Auto merge of #123258 - lnicola:sync-from-ra, r=lnicola

Subtree update of `rust-analyzer`

src/tools/rust-analyzer/.github/workflows/ci.yaml

@@ -71,7 +71,7 @@ jobs:
         run: echo "::add-matcher::.github/rust.json"
 
       - name: Cache Dependencies
-        uses: Swatinem/rust-cache@988c164c3d0e93c4dbab36aaf5bbeb77425b2894
+        uses: Swatinem/rust-cache@640a22190e7a783d4c409684cea558f081f92012
         with:
           key: ${{ env.RUST_CHANNEL }}
 
@@ -140,7 +140,7 @@ jobs:
           rustup target add ${{ env.targets }} ${{ env.targets_ide }}
 
       - name: Cache Dependencies
-        uses: Swatinem/rust-cache@988c164c3d0e93c4dbab36aaf5bbeb77425b2894
+        uses: Swatinem/rust-cache@640a22190e7a783d4c409684cea558f081f92012
 
       - name: Check
         run: |

src/tools/rust-analyzer/.github/workflows/publish-libs.yaml

@@ -32,4 +32,5 @@ jobs:
           git config --global user.name "GitHub Action"
           # Remove r-a crates from the workspaces so we don't auto-publish them as well
           sed -i 's/ "crates\/\*"//' ./Cargo.toml
+          sed -i 's/ "xtask\/"//' ./Cargo.toml
           cargo workspaces publish --yes --exact --from-git --no-git-commit --allow-dirty

src/tools/rust-analyzer/.github/workflows/release.yaml

@@ -36,6 +36,7 @@ jobs:
           - os: ubuntu-20.04
             target: x86_64-unknown-linux-gnu
             code-target: linux-x64
+            container: rockylinux:8
           - os: ubuntu-20.04
             target: aarch64-unknown-linux-gnu
             code-target: linux-arm64
@@ -58,10 +59,18 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: ${{ env.FETCH_DEPTH }}
 
+      - name: Install toolchain dependencies
+        if: matrix.container == 'rockylinux:8'
+        shell: bash
+        run: |
+          dnf install -y gcc
+          curl --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused -fsSL "https://sh.rustup.rs" | sh -s -- --profile minimal --default-toolchain none -y
+          echo "${CARGO_HOME:-$HOME/.cargo}/bin" >> $GITHUB_PATH
+
       - name: Install Rust toolchain
         run: |
           rustup update --no-self-update stable
@@ -69,9 +78,9 @@ jobs:
           rustup component add rust-src
 
       - name: Install Node.js
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 18
 
       - name: Update apt repositories
         if: matrix.target == 'aarch64-unknown-linux-gnu' || matrix.target == 'arm-unknown-linux-gnueabihf'
@@ -181,7 +190,7 @@ jobs:
       - name: Install Nodejs
         uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
 
       - run: echo "TAG=$(date --iso -u)" >> $GITHUB_ENV
         if: github.ref == 'refs/heads/release'

src/tools/rust-analyzer/Cargo.lock

@@ -594,6 +594,7 @@ dependencies = [
  "rustc-hash",
  "scoped-tls",
  "smallvec",
+ "span",
  "stdx",
  "syntax",
  "test-fixture",
@@ -637,6 +638,7 @@ dependencies = [
  "pulldown-cmark",
  "pulldown-cmark-to-cmark",
  "smallvec",
+ "span",
  "stdx",
  "syntax",
  "test-fixture",
@@ -732,6 +734,7 @@ dependencies = [
  "ide-db",
  "itertools",
  "once_cell",
+ "paths",
  "serde_json",
  "stdx",
  "syntax",
@@ -931,6 +934,7 @@ dependencies = [
  "hir-expand",
  "ide-db",
  "itertools",
+ "paths",
  "proc-macro-api",
  "project-model",
  "span",
@@ -1225,6 +1229,9 @@ checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
 [[package]]
 name = "paths"
 version = "0.0.0"
+dependencies = [
+ "camino",
+]
 
 [[package]]
 name = "percent-encoding"
@@ -1375,6 +1382,7 @@ dependencies = [
  "semver",
  "serde",
  "serde_json",
+ "span",
  "stdx",
  "toolchain",
  "tracing",
@@ -1432,9 +1440,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_abi"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2ae52e2d5b08762c9464b541345f519b8719d57b643b73632bade43ecece9dc"
+checksum = "b8709df2a746f055316bc0c62bd30948695a25e734863bf6e1f9755403e010ab"
 dependencies = [
  "bitflags 2.4.2",
  "ra-ap-rustc_index",
@@ -1443,9 +1451,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_index"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfd7e10c7853fe79443d46e1d2d8ab09fe99926118e59653fb8b480d5045f126"
+checksum = "9ad68bacffb87dcdbb23a3ce11261375078aaa06b85d348c49f39ffd5510dc20"
 dependencies = [
  "arrayvec",
  "ra-ap-rustc_index_macros",
@@ -1454,9 +1462,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_index_macros"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47f1d1c589be6c9a9e852fadee0e60329c0f862e87442ac2fe5adae30663cc76"
+checksum = "8782aaf3a113837c533dfb1c45df91cd17e1fdd1d2f9a20c2e0d1976025c4f1f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1466,9 +1474,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_lexer"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa852373a757b4c723bbdc96ced7f575cad68a1e266e45fee12bc4c69a482d80"
+checksum = "aab683fc8579d09eb72033bd5dc9ba6d701aa9645b5fed087ef19af71184dff3"
 dependencies = [
  "unicode-properties",
  "unicode-xid",
@@ -1476,9 +1484,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_parse_format"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2afe3c49accd95a53ac4d72ae13bafc7d115bdd80c8cd56ab09e6fc68f482210"
+checksum = "0bcf9ff5edbf784b67b8ad5e03a068f1300fcc24062c0d476b3018965135d933"
 dependencies = [
  "ra-ap-rustc_index",
  "ra-ap-rustc_lexer",
@@ -1486,9 +1494,9 @@ dependencies = [
 
 [[package]]
 name = "ra-ap-rustc_pattern_analysis"
-version = "0.42.0"
+version = "0.44.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1253da23515d80c377a3998731e0ec3794997b62b989fd47db73efbde6a0bd7c"
+checksum = "d63d1e1d5b2a13273cee1a10011147418f40e12b70f70578ce1dee0f1cafc334"
 dependencies = [
  "ra-ap-rustc_index",
  "rustc-hash",
@@ -1598,6 +1606,7 @@ dependencies = [
  "oorandom",
  "parking_lot",
  "parser",
+ "paths",
  "proc-macro-api",
  "profile",
  "project-model",
@@ -1869,20 +1878,16 @@ dependencies = [
  "itertools",
  "once_cell",
  "parser",
- "proc-macro2",
- "quote",
  "ra-ap-rustc_lexer",
  "rayon",
  "rowan",
  "rustc-hash",
  "smol_str",
- "sourcegen",
  "stdx",
  "test-utils",
  "text-edit",
  "tracing",
  "triomphe",
- "ungrammar",
 ]
 
 [[package]]
@@ -2024,6 +2029,7 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 name = "toolchain"
 version = "0.0.0"
 dependencies = [
+ "camino",
  "home",
 ]
 
@@ -2109,7 +2115,6 @@ name = "tt"
 version = "0.0.0"
 dependencies = [
  "smol_str",
- "span",
  "stdx",
  "text-size",
 ]
@@ -2438,8 +2443,12 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "flate2",
+ "itertools",
+ "proc-macro2",
+ "quote",
  "stdx",
  "time",
+ "ungrammar",
  "write-json",
  "xflags",
  "xshell",

src/tools/rust-analyzer/Cargo.toml

@@ -84,11 +84,11 @@ tt = { path = "./crates/tt", version = "0.0.0" }
 vfs-notify = { path = "./crates/vfs-notify", version = "0.0.0" }
 vfs = { path = "./crates/vfs", version = "0.0.0" }
 
-ra-ap-rustc_lexer = { version = "0.42.0", default-features = false }
+ra-ap-rustc_lexer = { version = "0.44.0", default-features = false }
-ra-ap-rustc_parse_format = { version = "0.42.0", default-features = false }
+ra-ap-rustc_parse_format = { version = "0.44.0", default-features = false }
-ra-ap-rustc_index = { version = "0.42.0", default-features = false }
+ra-ap-rustc_index = { version = "0.44.0", default-features = false }
-ra-ap-rustc_abi = { version = "0.42.0", default-features = false }
+ra-ap-rustc_abi = { version = "0.44.0", default-features = false }
-ra-ap-rustc_pattern_analysis = { version = "0.42.0", default-features = false }
+ra-ap-rustc_pattern_analysis = { version = "0.44.0", default-features = false }
 
 # local crates that aren't published to crates.io. These should not have versions.
 sourcegen = { path = "./crates/sourcegen" }
@@ -105,6 +105,7 @@ anyhow = "1.0.75"
 arrayvec = "0.7.4"
 bitflags = "2.4.1"
 cargo_metadata = "0.18.1"
+camino = "1.1.6"
 chalk-solve = { version = "0.96.0", default-features = false }
 chalk-ir = "0.96.0"
 chalk-recursive = { version = "0.96.0", default-features = false }

src/tools/rust-analyzer/crates/base-db/src/input.rs

@@ -6,11 +6,12 @@
 //! actual IO. See `vfs` and `project_model` in the `rust-analyzer` crate for how
 //! actual IO is done and lowered to input.
 
-use std::{fmt, mem, ops, str::FromStr};
+use std::{fmt, mem, ops};
 
 use cfg::CfgOptions;
 use la_arena::{Arena, Idx, RawIdx};
 use rustc_hash::{FxHashMap, FxHashSet};
+use span::Edition;
 use syntax::SmolStr;
 use triomphe::Arc;
 use vfs::{file_set::FileSet, AbsPathBuf, AnchoredPath, FileId, VfsPath};
@@ -293,42 +294,11 @@ pub struct CrateData {
     pub is_proc_macro: bool,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Edition {
-    Edition2015,
-    Edition2018,
-    Edition2021,
-    Edition2024,
-}
-
-impl Edition {
-    pub const CURRENT: Edition = Edition::Edition2021;
-    pub const DEFAULT: Edition = Edition::Edition2015;
-}
-
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct Env {
     entries: FxHashMap<String, String>,
 }
 
-impl Env {
-    pub fn new_for_test_fixture() -> Self {
-        Env {
-            entries: FxHashMap::from_iter([(
-                String::from("__ra_is_test_fixture"),
-                String::from("__ra_is_test_fixture"),
-            )]),
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub enum DependencyKind {
-    Normal,
-    Dev,
-    Build,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Dependency {
     pub crate_id: CrateId,
@@ -530,13 +500,6 @@ impl CrateGraph {
         }
     }
 
-    // FIXME: this only finds one crate with the given root; we could have multiple
-    pub fn crate_id_for_crate_root(&self, file_id: FileId) -> Option<CrateId> {
-        let (crate_id, _) =
-            self.arena.iter().find(|(_crate_id, data)| data.root_file_id == file_id)?;
-        Some(crate_id)
-    }
-
     pub fn sort_deps(&mut self) {
         self.arena
             .iter_mut()
@@ -653,6 +616,10 @@ impl CrateGraph {
         }
         id_map
     }
+
+    pub fn shrink_to_fit(&mut self) {
+        self.arena.shrink_to_fit();
+    }
 }
 
 impl ops::Index<CrateId> for CrateGraph {
@@ -670,32 +637,6 @@ impl CrateData {
     }
 }
 
-impl FromStr for Edition {
-    type Err = ParseEditionError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let res = match s {
-            "2015" => Edition::Edition2015,
-            "2018" => Edition::Edition2018,
-            "2021" => Edition::Edition2021,
-            "2024" => Edition::Edition2024,
-            _ => return Err(ParseEditionError { invalid_input: s.to_owned() }),
-        };
-        Ok(res)
-    }
-}
-
-impl fmt::Display for Edition {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(match self {
-            Edition::Edition2015 => "2015",
-            Edition::Edition2018 => "2018",
-            Edition::Edition2021 => "2021",
-            Edition::Edition2024 => "2024",
-        })
-    }
-}
-
 impl Extend<(String, String)> for Env {
     fn extend<T: IntoIterator<Item = (String, String)>>(&mut self, iter: T) {
         self.entries.extend(iter);
@@ -722,19 +663,6 @@ impl Env {
     }
 }
 
-#[derive(Debug)]
-pub struct ParseEditionError {
-    invalid_input: String,
-}
-
-impl fmt::Display for ParseEditionError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "invalid edition: {:?}", self.invalid_input)
-    }
-}
-
-impl std::error::Error for ParseEditionError {}
-
 #[derive(Debug)]
 pub struct CyclicDependenciesError {
     path: Vec<(CrateId, Option<CrateDisplayName>)>,

src/tools/rust-analyzer/crates/base-db/src/lib.rs

@@ -14,9 +14,9 @@ use triomphe::Arc;
 pub use crate::{
     change::FileChange,
     input::{
-        CrateData, CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency,
+        CrateData, CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency, Env,
-        DependencyKind, Edition, Env, LangCrateOrigin, ProcMacroPaths, ReleaseChannel, SourceRoot,
+        LangCrateOrigin, ProcMacroPaths, ReleaseChannel, SourceRoot, SourceRootId,
-        SourceRootId, TargetLayoutLoadResult,
+        TargetLayoutLoadResult,
     },
 };
 pub use salsa::{self, Cancelled};

src/tools/rust-analyzer/crates/flycheck/src/lib.rs

@@ -8,10 +8,10 @@
 
 #![warn(rust_2018_idioms, unused_lifetimes)]
 
-use std::{fmt, io, path::PathBuf, process::Command, time::Duration};
+use std::{fmt, io, process::Command, time::Duration};
 
 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
@@ -53,7 +53,7 @@ pub enum FlycheckConfig {
         extra_args: Vec<String>,
         extra_env: FxHashMap<String, String>,
         ansi_color_output: bool,
-        target_dir: Option<PathBuf>,
+        target_dir: Option<Utf8PathBuf>,
     },
     CustomCommand {
         command: String,
@@ -363,7 +363,7 @@ impl FlycheckActor {
                 });
 
                 cmd.arg("--manifest-path");
-                cmd.arg(self.root.join("Cargo.toml").as_os_str());
+                cmd.arg(self.root.join("Cargo.toml"));
 
                 for target in target_triples {
                     cmd.args(["--target", target.as_str()]);

src/tools/rust-analyzer/crates/flycheck/src/test_runner.rs

@@ -55,13 +55,16 @@ pub struct CargoTestHandle {
 }
 
 // Example of a cargo test command:
-// cargo test -- module::func -Z unstable-options --format=json
+// cargo test --workspace --no-fail-fast -- module::func -Z unstable-options --format=json
 
 impl CargoTestHandle {
     pub fn new(path: Option<&str>) -> std::io::Result<Self> {
         let mut cmd = Command::new(Tool::Cargo.path());
         cmd.env("RUSTC_BOOTSTRAP", "1");
         cmd.arg("test");
+        cmd.arg("--workspace");
+        // --no-fail-fast is needed to ensure that all requested tests will run
+        cmd.arg("--no-fail-fast");
         cmd.arg("--");
         if let Some(path) = path {
             cmd.arg(path);

src/tools/rust-analyzer/crates/hir-def/src/attr.rs

@@ -148,12 +148,12 @@ impl Attrs {
         }
     }
 
-    pub fn lang(&self) -> Option<&SmolStr> {
+    pub fn lang(&self) -> Option<&str> {
         self.by_key("lang").string_value()
     }
 
     pub fn lang_item(&self) -> Option<LangItem> {
-        self.by_key("lang").string_value().and_then(|it| LangItem::from_str(it))
+        self.by_key("lang").string_value().and_then(LangItem::from_str)
     }
 
     pub fn has_doc_hidden(&self) -> bool {
@@ -178,7 +178,7 @@ impl Attrs {
         self.doc_exprs().flat_map(|doc_expr| doc_expr.aliases().to_vec())
     }
 
-    pub fn export_name(&self) -> Option<&SmolStr> {
+    pub fn export_name(&self) -> Option<&str> {
         self.by_key("export_name").string_value()
     }
 
@@ -565,7 +565,7 @@ impl<'attr> AttrQuery<'attr> {
         self.attrs().filter_map(|attr| attr.token_tree_value())
     }
 
-    pub fn string_value(self) -> Option<&'attr SmolStr> {
+    pub fn string_value(self) -> Option<&'attr str> {
         self.attrs().find_map(|attr| attr.string_value())
     }
 

src/tools/rust-analyzer/crates/hir-def/src/data.rs

@@ -453,8 +453,8 @@ impl ProcMacroData {
             (
                 def.name,
                 match def.kind {
-                    ProcMacroKind::CustomDerive { helpers } => Some(helpers),
+                    ProcMacroKind::Derive { helpers } => Some(helpers),
-                    ProcMacroKind::FnLike | ProcMacroKind::Attr => None,
+                    ProcMacroKind::Bang | ProcMacroKind::Attr => None,
                 },
             )
         } else {
@@ -484,10 +484,11 @@ impl ExternCrateDeclData {
         let extern_crate = &item_tree[loc.id.value];
 
         let name = extern_crate.name.clone();
+        let krate = loc.container.krate();
         let crate_id = if name == hir_expand::name![self] {
-            Some(loc.container.krate())
+            Some(krate)
         } else {
-            db.crate_def_map(loc.container.krate())
+            db.crate_def_map(krate)
                 .extern_prelude()
                 .find(|&(prelude_name, ..)| *prelude_name == name)
                 .map(|(_, (root, _))| root.krate())

src/tools/rust-analyzer/crates/hir-def/src/generics.rs

@@ -22,8 +22,8 @@ use crate::{
     lower::LowerCtx,
     nameres::{DefMap, MacroSubNs},
     type_ref::{ConstRef, LifetimeRef, TypeBound, TypeRef},
-    AdtId, ConstParamId, GenericDefId, HasModule, ItemTreeLoc, LocalTypeOrConstParamId, Lookup,
+    AdtId, ConstParamId, GenericDefId, HasModule, ItemTreeLoc, LifetimeParamId,
-    TypeOrConstParamId, TypeParamId,
+    LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,
 };
 
 /// Data about a generic type parameter (to a function, struct, impl, ...).
@@ -102,6 +102,52 @@ impl TypeOrConstParamData {
 
 impl_from!(TypeParamData, ConstParamData for TypeOrConstParamData);
 
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub enum GenericParamData {
+    TypeParamData(TypeParamData),
+    ConstParamData(ConstParamData),
+    LifetimeParamData(LifetimeParamData),
+}
+
+impl GenericParamData {
+    pub fn name(&self) -> Option<&Name> {
+        match self {
+            GenericParamData::TypeParamData(it) => it.name.as_ref(),
+            GenericParamData::ConstParamData(it) => Some(&it.name),
+            GenericParamData::LifetimeParamData(it) => Some(&it.name),
+        }
+    }
+
+    pub fn type_param(&self) -> Option<&TypeParamData> {
+        match self {
+            GenericParamData::TypeParamData(it) => Some(it),
+            _ => None,
+        }
+    }
+
+    pub fn const_param(&self) -> Option<&ConstParamData> {
+        match self {
+            GenericParamData::ConstParamData(it) => Some(it),
+            _ => None,
+        }
+    }
+
+    pub fn lifetime_param(&self) -> Option<&LifetimeParamData> {
+        match self {
+            GenericParamData::LifetimeParamData(it) => Some(it),
+            _ => None,
+        }
+    }
+}
+
+impl_from!(TypeParamData, ConstParamData, LifetimeParamData for GenericParamData);
+
+pub enum GenericParamDataRef<'a> {
+    TypeParamData(&'a TypeParamData),
+    ConstParamData(&'a ConstParamData),
+    LifetimeParamData(&'a LifetimeParamData),
+}
+
 /// Data about the generic parameters of a function, struct, impl, etc.
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub struct GenericParams {
@@ -358,6 +404,15 @@ impl GenericParamsCollector {
 }
 
 impl GenericParams {
+    /// Number of Generic parameters (type_or_consts + lifetimes)
+    pub fn len(&self) -> usize {
+        self.type_or_consts.len() + self.lifetimes.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Iterator of type_or_consts field
     pub fn iter(
         &self,
@@ -365,6 +420,13 @@ impl GenericParams {
         self.type_or_consts.iter()
     }
 
+    /// Iterator of lifetimes field
+    pub fn iter_lt(
+        &self,
+    ) -> impl DoubleEndedIterator<Item = (Idx<LifetimeParamData>, &LifetimeParamData)> {
+        self.lifetimes.iter()
+    }
+
     pub(crate) fn generic_params_query(
         db: &dyn DefDatabase,
         def: GenericDefId,
@@ -507,4 +569,18 @@ impl GenericParams {
             .then(|| id)
         })
     }
+
+    pub fn find_lifetime_by_name(
+        &self,
+        name: &Name,
+        parent: GenericDefId,
+    ) -> Option<LifetimeParamId> {
+        self.lifetimes.iter().find_map(|(id, p)| {
+            if &p.name == name {
+                Some(LifetimeParamId { local_id: id, parent })
+            } else {
+                None
+            }
+        })
+    }
 }

src/tools/rust-analyzer/crates/hir-def/src/item_tree/pretty.rs

@@ -526,7 +526,7 @@ impl Printer<'_> {
     }
 
     fn print_generic_params(&mut self, params: &GenericParams) {
-        if params.type_or_consts.is_empty() && params.lifetimes.is_empty() {
+        if params.is_empty() {
             return;
         }
 

src/tools/rust-analyzer/crates/hir-def/src/lang_item.rs

@@ -192,7 +192,7 @@ impl LangItems {
 
 pub(crate) fn lang_attr(db: &dyn DefDatabase, item: AttrDefId) -> Option<LangItem> {
     let attrs = db.attrs(item);
-    attrs.by_key("lang").string_value().and_then(|it| LangItem::from_str(it))
+    attrs.by_key("lang").string_value().and_then(LangItem::from_str)
 }
 
 pub(crate) fn notable_traits_in_deps(

src/tools/rust-analyzer/crates/hir-def/src/lib.rs

@@ -73,7 +73,7 @@ use std::{
 use base_db::{
     impl_intern_key,
     salsa::{self, impl_intern_value_trivial},
-    CrateId, Edition,
+    CrateId,
 };
 use hir_expand::{
     builtin_attr_macro::BuiltinAttrExpander,
@@ -90,7 +90,7 @@ use hir_expand::{
 use item_tree::ExternBlock;
 use la_arena::Idx;
 use nameres::DefMap;
-use span::{AstIdNode, FileAstId, FileId, SyntaxContextId};
+use span::{AstIdNode, Edition, FileAstId, FileId, SyntaxContextId};
 use stdx::impl_from;
 use syntax::{ast, AstNode};
 

src/tools/rust-analyzer/crates/hir-def/src/macro_expansion_tests/mbe.rs

@@ -1449,6 +1449,7 @@ ok!();
 #[test]
 fn test_new_std_matches() {
     check(
+        //- edition:2021
         r#"
 macro_rules! matches {
     ($expression:expr, $pattern:pat $(if $guard:expr)? $(,)?) => {
@@ -1480,6 +1481,90 @@ fn main() {
     );
 }
 
+#[test]
+fn test_hygienic_pat() {
+    check(
+        r#"
+//- /new.rs crate:new deps:old edition:2015
+old::make!();
+fn main() {
+    matches!(0, 0 | 1 if true);
+}
+//- /old.rs crate:old edition:2021
+#[macro_export]
+macro_rules! make {
+    () => {
+        macro_rules! matches {
+            ($expression:expr, $pattern:pat if $guard:expr ) => {
+                match $expression {
+                    $pattern if $guard => true,
+                    _ => false
+                }
+            };
+        }
+    }
+}
+ "#,
+        expect![[r#"
+macro_rules !matches {
+    ($expression: expr, $pattern: pat if $guard: expr) = > {
+        match $expression {
+            $pattern if $guard = > true , _ = > false
+        }
+    }
+    ;
+}
+fn main() {
+    match 0 {
+        0|1 if true =>true , _=>false
+    };
+}
+"#]],
+    );
+    check(
+        r#"
+//- /new.rs crate:new deps:old edition:2021
+old::make!();
+fn main() {
+    matches/*+errors*/!(0, 0 | 1 if true);
+}
+//- /old.rs crate:old edition:2015
+#[macro_export]
+macro_rules! make {
+    () => {
+        macro_rules! matches {
+            ($expression:expr, $pattern:pat if $guard:expr ) => {
+                match $expression {
+                    $pattern if $guard => true,
+                    _ => false
+                }
+            };
+        }
+    }
+}
+ "#,
+        expect![[r#"
+macro_rules !matches {
+    ($expression: expr, $pattern: pat if $guard: expr) = > {
+        match $expression {
+            $pattern if $guard = > true , _ = > false
+        }
+    }
+    ;
+}
+fn main() {
+    /* error: unexpected token in input *//* parse error: expected expression */
+/* parse error: expected FAT_ARROW */
+/* parse error: expected `,` */
+/* parse error: expected pattern */
+match 0 {
+        0 if $guard=>true , _=>false
+    };
+}
+"#]],
+    );
+}
+
 #[test]
 fn test_dollar_crate_lhs_is_not_meta() {
     check(

src/tools/rust-analyzer/crates/hir-def/src/nameres.rs

@@ -59,14 +59,14 @@ mod tests;
 
 use std::ops::Deref;
 
-use base_db::{CrateId, Edition, FileId};
+use base_db::{CrateId, FileId};
 use hir_expand::{
     name::Name, proc_macro::ProcMacroKind, ErasedAstId, HirFileId, InFile, MacroCallId, MacroDefId,
 };
 use itertools::Itertools;
 use la_arena::Arena;
 use rustc_hash::{FxHashMap, FxHashSet};
-use span::{FileAstId, ROOT_ERASED_FILE_AST_ID};
+use span::{Edition, FileAstId, ROOT_ERASED_FILE_AST_ID};
 use stdx::format_to;
 use syntax::{ast, SmolStr};
 use triomphe::Arc;
@@ -737,7 +737,7 @@ impl MacroSubNs {
             MacroId::ProcMacroId(it) => {
                 return match it.lookup(db).kind {
                     ProcMacroKind::CustomDerive | ProcMacroKind::Attr => Self::Attr,
-                    ProcMacroKind::FuncLike => Self::Bang,
+                    ProcMacroKind::Bang => Self::Bang,
                 };
             }
         };

src/tools/rust-analyzer/crates/hir-def/src/nameres/attr_resolution.rs

@@ -136,6 +136,7 @@ pub(super) fn derive_macro_as_call_id(
     call_site: SyntaxContextId,
     krate: CrateId,
     resolver: impl Fn(path::ModPath) -> Option<(MacroId, MacroDefId)>,
+    derive_macro_id: MacroCallId,
 ) -> Result<(MacroId, MacroDefId, MacroCallId), UnresolvedMacro> {
     let (macro_id, def_id) = resolver(item_attr.path.clone())
         .filter(|(_, def_id)| def_id.is_derive())
@@ -147,6 +148,7 @@ pub(super) fn derive_macro_as_call_id(
             ast_id: item_attr.ast_id,
             derive_index: derive_pos,
             derive_attr_index,
+            derive_macro_id,
         },
         call_site,
     );

src/tools/rust-analyzer/crates/hir-def/src/nameres/collector.rs

@@ -5,7 +5,7 @@
 
 use std::{cmp::Ordering, iter, mem, ops::Not};
 
-use base_db::{CrateId, Dependency, Edition, FileId};
+use base_db::{CrateId, Dependency, FileId};
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{
@@ -22,9 +22,9 @@ use itertools::{izip, Itertools};
 use la_arena::Idx;
 use limit::Limit;
 use rustc_hash::{FxHashMap, FxHashSet};
-use span::{ErasedFileAstId, FileAstId, Span, SyntaxContextId};
+use span::{Edition, ErasedFileAstId, FileAstId, Span, SyntaxContextId};
 use stdx::always;
-use syntax::{ast, SmolStr};
+use syntax::ast;
 use triomphe::Arc;
 
 use crate::{
@@ -237,6 +237,8 @@ enum MacroDirectiveKind {
         derive_attr: AttrId,
         derive_pos: usize,
         ctxt: SyntaxContextId,
+        /// The "parent" macro it is resolved to.
+        derive_macro_id: MacroCallId,
     },
     Attr {
         ast_id: AstIdWithPath<ast::Item>,
@@ -312,7 +314,7 @@ impl DefCollector<'_> {
                     }
                 }
                 () if *attr_name == hir_expand::name![crate_type] => {
-                    if let Some("proc-macro") = attr.string_value().map(SmolStr::as_str) {
+                    if let Some("proc-macro") = attr.string_value() {
                         self.is_proc_macro = true;
                     }
                 }
@@ -602,7 +604,7 @@ impl DefCollector<'_> {
         .intern(self.db);
         self.define_proc_macro(def.name.clone(), proc_macro_id);
         let crate_data = Arc::get_mut(&mut self.def_map.data).unwrap();
-        if let ProcMacroKind::CustomDerive { helpers } = def.kind {
+        if let ProcMacroKind::Derive { helpers } = def.kind {
             crate_data.exported_derives.insert(self.db.macro_def(proc_macro_id.into()), helpers);
         }
         crate_data.fn_proc_macro_mapping.insert(fn_id, proc_macro_id);
@@ -1146,7 +1148,13 @@ impl DefCollector<'_> {
                         return Resolved::Yes;
                     }
                 }
-                MacroDirectiveKind::Derive { ast_id, derive_attr, derive_pos, ctxt: call_site } => {
+                MacroDirectiveKind::Derive {
+                    ast_id,
+                    derive_attr,
+                    derive_pos,
+                    ctxt: call_site,
+                    derive_macro_id,
+                } => {
                     let id = derive_macro_as_call_id(
                         self.db,
                         ast_id,
@@ -1155,6 +1163,7 @@ impl DefCollector<'_> {
                         *call_site,
                         self.def_map.krate,
                         resolver,
+                        *derive_macro_id,
                     );
 
                     if let Ok((macro_id, def_id, call_id)) = id {
@@ -1224,6 +1233,8 @@ impl DefCollector<'_> {
                         _ => return Resolved::No,
                     };
 
+                    let call_id =
+                        attr_macro_as_call_id(self.db, file_ast_id, attr, self.def_map.krate, def);
                     if let MacroDefId {
                         kind:
                             MacroDefKind::BuiltInAttr(
@@ -1252,6 +1263,7 @@ impl DefCollector<'_> {
                                 return recollect_without(self);
                             }
                         };
+
                         let ast_id = ast_id.with_value(ast_adt_id);
 
                         match attr.parse_path_comma_token_tree(self.db.upcast()) {
@@ -1267,6 +1279,7 @@ impl DefCollector<'_> {
                                             derive_attr: attr.id,
                                             derive_pos: idx,
                                             ctxt: call_site.ctx,
+                                            derive_macro_id: call_id,
                                         },
                                         container: directive.container,
                                     });
@@ -1301,10 +1314,6 @@ impl DefCollector<'_> {
                         return recollect_without(self);
                     }
 
-                    // Not resolved to a derive helper or the derive attribute, so try to treat as a normal attribute.
-                    let call_id =
-                        attr_macro_as_call_id(self.db, file_ast_id, attr, self.def_map.krate, def);
-
                     // Skip #[test]/#[bench] expansion, which would merely result in more memory usage
                     // due to duplicating functions into macro expansions
                     if matches!(
@@ -1460,13 +1469,20 @@ impl DefCollector<'_> {
                         ));
                     }
                 }
-                MacroDirectiveKind::Derive { ast_id, derive_attr, derive_pos, ctxt: _ } => {
+                MacroDirectiveKind::Derive {
+                    ast_id,
+                    derive_attr,
+                    derive_pos,
+                    derive_macro_id,
+                    ..
+                } => {
                     self.def_map.diagnostics.push(DefDiagnostic::unresolved_macro_call(
                         directive.module_id,
                         MacroCallKind::Derive {
                             ast_id: ast_id.ast_id,
                             derive_attr_index: *derive_attr,
                             derive_index: *derive_pos as u32,
+                            derive_macro_id: *derive_macro_id,
                         },
                         ast_id.path.clone(),
                     ));
@@ -1902,7 +1918,7 @@ impl ModCollector<'_, '_> {
     }
 
     fn collect_module(&mut self, module_id: FileItemTreeId<Mod>, attrs: &Attrs) {
-        let path_attr = attrs.by_key("path").string_value().map(SmolStr::as_str);
+        let path_attr = attrs.by_key("path").string_value();
         let is_macro_use = attrs.by_key("macro_use").exists();
         let module = &self.item_tree[module_id];
         match &module.kind {
@@ -2146,7 +2162,7 @@ impl ModCollector<'_, '_> {
                 Some(it) => {
                     // FIXME: a hacky way to create a Name from string.
                     name = tt::Ident {
-                        text: it.clone(),
+                        text: it.into(),
                         span: Span {
                             range: syntax::TextRange::empty(syntax::TextSize::new(0)),
                             anchor: span::SpanAnchor {

src/tools/rust-analyzer/crates/hir-def/src/nameres/path_resolution.rs

@@ -10,8 +10,8 @@
 //!
 //! `ReachedFixedPoint` signals about this.
 
-use base_db::Edition;
 use hir_expand::{name::Name, Lookup};
+use span::Edition;
 use triomphe::Arc;
 
 use crate::{

src/tools/rust-analyzer/crates/hir-def/src/nameres/proc_macro.rs

@@ -13,18 +13,16 @@ pub struct ProcMacroDef {
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum ProcMacroKind {
-    CustomDerive { helpers: Box<[Name]> },
+    Derive { helpers: Box<[Name]> },
-    FnLike,
+    Bang,
     Attr,
 }
 
 impl ProcMacroKind {
     pub(super) fn to_basedb_kind(&self) -> hir_expand::proc_macro::ProcMacroKind {
         match self {
-            ProcMacroKind::CustomDerive { .. } => {
+            ProcMacroKind::Derive { .. } => hir_expand::proc_macro::ProcMacroKind::CustomDerive,
-                hir_expand::proc_macro::ProcMacroKind::CustomDerive
+            ProcMacroKind::Bang => hir_expand::proc_macro::ProcMacroKind::Bang,
-            }
-            ProcMacroKind::FnLike => hir_expand::proc_macro::ProcMacroKind::FuncLike,
             ProcMacroKind::Attr => hir_expand::proc_macro::ProcMacroKind::Attr,
         }
     }
@@ -34,13 +32,13 @@ impl Attrs {
     #[rustfmt::skip]
     pub fn parse_proc_macro_decl(&self, func_name: &Name) -> Option<ProcMacroDef> {
         if self.is_proc_macro() {
-            Some(ProcMacroDef { name: func_name.clone(), kind: ProcMacroKind::FnLike })
+            Some(ProcMacroDef { name: func_name.clone(), kind: ProcMacroKind::Bang })
         } else if self.is_proc_macro_attribute() {
             Some(ProcMacroDef { name: func_name.clone(), kind: ProcMacroKind::Attr })
         } else if self.by_key("proc_macro_derive").exists() {
             let derive = self.by_key("proc_macro_derive").tt_values().next()?;
             let def = parse_macro_name_and_helper_attrs(&derive.token_trees)
-                .map(|(name, helpers)| ProcMacroDef { name, kind: ProcMacroKind::CustomDerive { helpers } });
+                .map(|(name, helpers)| ProcMacroDef { name, kind: ProcMacroKind::Derive { helpers } });
 
             if def.is_none() {
                 tracing::trace!("malformed `#[proc_macro_derive]`: {}", derive);

src/tools/rust-analyzer/crates/hir-def/src/resolver.rs

@@ -24,6 +24,7 @@ use crate::{
     nameres::{DefMap, MacroSubNs},
     path::{ModPath, Path, PathKind},
     per_ns::PerNs,
+    type_ref::LifetimeRef,
     visibility::{RawVisibility, Visibility},
     AdtId, ConstId, ConstParamId, CrateRootModuleId, DefWithBodyId, EnumId, EnumVariantId,
     ExternBlockId, ExternCrateId, FunctionId, GenericDefId, GenericParamId, HasModule, ImplId,
@@ -120,6 +121,12 @@ pub enum ValueNs {
     GenericParam(ConstParamId),
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub enum LifetimeNs {
+    Static,
+    LifetimeParam(LifetimeParamId),
+}
+
 impl Resolver {
     /// Resolve known trait from std, like `std::futures::Future`
     pub fn resolve_known_trait(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<TraitId> {
@@ -418,6 +425,19 @@ impl Resolver {
         self.resolve_path_as_macro(db, path, expected_macro_kind).map(|(it, _)| db.macro_def(it))
     }
 
+    pub fn resolve_lifetime(&self, lifetime: &LifetimeRef) -> Option<LifetimeNs> {
+        if lifetime.name == name::known::STATIC_LIFETIME {
+            return Some(LifetimeNs::Static);
+        }
+
+        self.scopes().find_map(|scope| match scope {
+            Scope::GenericParams { def, params } => {
+                params.find_lifetime_by_name(&lifetime.name, *def).map(LifetimeNs::LifetimeParam)
+            }
+            _ => None,
+        })
+    }
+
     /// Returns a set of names available in the current scope.
     ///
     /// Note that this is a somewhat fuzzy concept -- internally, the compiler

src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs

@@ -8,8 +8,8 @@ use intern::Interned;
 use mbe::{syntax_node_to_token_tree, DelimiterKind, Punct};
 use smallvec::{smallvec, SmallVec};
 use span::{Span, SyntaxContextId};
-use syntax::{ast, match_ast, AstNode, AstToken, SmolStr, SyntaxNode};
+use syntax::{ast, format_smolstr, match_ast, AstNode, AstToken, SmolStr, SyntaxNode};
-use triomphe::Arc;
+use triomphe::ThinArc;
 
 use crate::{
     db::ExpandDatabase,
@@ -22,8 +22,7 @@ use crate::{
 /// Syntactical attributes, without filtering of `cfg_attr`s.
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct RawAttrs {
-    // FIXME: Make this a ThinArc
+    entries: Option<ThinArc<(), Attr>>,
-    entries: Option<Arc<[Attr]>>,
 }
 
 impl ops::Deref for RawAttrs {
@@ -31,7 +30,7 @@ impl ops::Deref for RawAttrs {
 
     fn deref(&self) -> &[Attr] {
         match &self.entries {
-            Some(it) => it,
+            Some(it) => &it.slice,
             None => &[],
         }
     }
@@ -45,20 +44,34 @@ impl RawAttrs {
         owner: &dyn ast::HasAttrs,
         span_map: SpanMapRef<'_>,
     ) -> Self {
-        let entries = collect_attrs(owner).filter_map(|(id, attr)| match attr {
+        let entries: Vec<_> = collect_attrs(owner)
-            Either::Left(attr) => {
+            .filter_map(|(id, attr)| match attr {
-                attr.meta().and_then(|meta| Attr::from_src(db, meta, span_map, id))
+                Either::Left(attr) => {
-            }
+                    attr.meta().and_then(|meta| Attr::from_src(db, meta, span_map, id))
-            Either::Right(comment) => comment.doc_comment().map(|doc| Attr {
+                }
-                id,
+                Either::Right(comment) => comment.doc_comment().map(|doc| {
-                input: Some(Interned::new(AttrInput::Literal(SmolStr::new(doc)))),
+                    let span = span_map.span_for_range(comment.syntax().text_range());
-                path: Interned::new(ModPath::from(crate::name!(doc))),
+                    Attr {
-                ctxt: span_map.span_for_range(comment.syntax().text_range()).ctx,
+                        id,
-            }),
+                        input: Some(Interned::new(AttrInput::Literal(tt::Literal {
-        });
+                            // FIXME: Escape quotes from comment content
-        let entries: Arc<[Attr]> = Arc::from_iter(entries);
+                            text: SmolStr::new(format_smolstr!("\"{doc}\"",)),
+                            span,
+                        }))),
+                        path: Interned::new(ModPath::from(crate::name!(doc))),
+                        ctxt: span.ctx,
+                    }
+                }),
+            })
+            .collect();
 
-        Self { entries: if entries.is_empty() { None } else { Some(entries) } }
+        let entries = if entries.is_empty() {
+            None
+        } else {
+            Some(ThinArc::from_header_and_iter((), entries.into_iter()))
+        };
+
+        RawAttrs { entries }
     }
 
     pub fn from_attrs_owner(
@@ -75,16 +88,20 @@ impl RawAttrs {
             (None, entries @ Some(_)) => Self { entries },
             (Some(entries), None) => Self { entries: Some(entries.clone()) },
             (Some(a), Some(b)) => {
-                let last_ast_index = a.last().map_or(0, |it| it.id.ast_index() + 1) as u32;
+                let last_ast_index = a.slice.last().map_or(0, |it| it.id.ast_index() + 1) as u32;
-                Self {
+                let items = a
-                    entries: Some(Arc::from_iter(a.iter().cloned().chain(b.iter().map(|it| {
+                    .slice
+                    .iter()
+                    .cloned()
+                    .chain(b.slice.iter().map(|it| {
                         let mut it = it.clone();
                         it.id.id = (it.id.ast_index() as u32 + last_ast_index)
                             | (it.id.cfg_attr_index().unwrap_or(0) as u32)
                                 << AttrId::AST_INDEX_BITS;
                         it
-                    })))),
+                    }))
-                }
+                    .collect::<Vec<_>>();
+                Self { entries: Some(ThinArc::from_header_and_iter((), items.into_iter())) }
             }
         }
     }
@@ -100,41 +117,47 @@ impl RawAttrs {
         }
 
         let crate_graph = db.crate_graph();
-        let new_attrs = Arc::from_iter(self.iter().flat_map(|attr| -> SmallVec<[_; 1]> {
+        let new_attrs =
-            let is_cfg_attr =
+            self.iter()
-                attr.path.as_ident().map_or(false, |name| *name == crate::name![cfg_attr]);
+                .flat_map(|attr| -> SmallVec<[_; 1]> {
-            if !is_cfg_attr {
+                    let is_cfg_attr =
-                return smallvec![attr.clone()];
+                        attr.path.as_ident().map_or(false, |name| *name == crate::name![cfg_attr]);
-            }
+                    if !is_cfg_attr {
+                        return smallvec![attr.clone()];
+                    }
 
-            let subtree = match attr.token_tree_value() {
+                    let subtree = match attr.token_tree_value() {
-                Some(it) => it,
+                        Some(it) => it,
-                _ => return smallvec![attr.clone()],
+                        _ => return smallvec![attr.clone()],
-            };
+                    };
 
-            let (cfg, parts) = match parse_cfg_attr_input(subtree) {
+                    let (cfg, parts) = match parse_cfg_attr_input(subtree) {
-                Some(it) => it,
+                        Some(it) => it,
-                None => return smallvec![attr.clone()],
+                        None => return smallvec![attr.clone()],
-            };
+                    };
-            let index = attr.id;
+                    let index = attr.id;
-            let attrs = parts
+                    let attrs = parts.enumerate().take(1 << AttrId::CFG_ATTR_BITS).filter_map(
-                .enumerate()
+                        |(idx, attr)| Attr::from_tt(db, attr, index.with_cfg_attr(idx)),
-                .take(1 << AttrId::CFG_ATTR_BITS)
+                    );
-                .filter_map(|(idx, attr)| Attr::from_tt(db, attr, index.with_cfg_attr(idx)));
 
-            let cfg_options = &crate_graph[krate].cfg_options;
+                    let cfg_options = &crate_graph[krate].cfg_options;
-            let cfg = Subtree { delimiter: subtree.delimiter, token_trees: Box::from(cfg) };
+                    let cfg = Subtree { delimiter: subtree.delimiter, token_trees: Box::from(cfg) };
-            let cfg = CfgExpr::parse(&cfg);
+                    let cfg = CfgExpr::parse(&cfg);
-            if cfg_options.check(&cfg) == Some(false) {
+                    if cfg_options.check(&cfg) == Some(false) {
-                smallvec![]
+                        smallvec![]
-            } else {
+                    } else {
-                cov_mark::hit!(cfg_attr_active);
+                        cov_mark::hit!(cfg_attr_active);
 
-                attrs.collect()
+                        attrs.collect()
-            }
+                    }
-        }));
+                })
-
+                .collect::<Vec<_>>();
-        RawAttrs { entries: Some(new_attrs) }
+        let entries = if new_attrs.is_empty() {
+            None
+        } else {
+            Some(ThinArc::from_header_and_iter((), new_attrs.into_iter()))
+        };
+        RawAttrs { entries }
     }
 }
 
@@ -179,8 +202,7 @@ pub struct Attr {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum AttrInput {
     /// `#[attr = "string"]`
-    // FIXME: This is losing span
+    Literal(tt::Literal),
-    Literal(SmolStr),
     /// `#[attr(subtree)]`
     TokenTree(Box<tt::Subtree>),
 }
@@ -188,7 +210,7 @@ pub enum AttrInput {
 impl fmt::Display for AttrInput {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            AttrInput::Literal(lit) => write!(f, " = \"{}\"", lit.escape_debug()),
+            AttrInput::Literal(lit) => write!(f, " = {lit}"),
             AttrInput::TokenTree(tt) => tt.fmt(f),
         }
     }
@@ -208,11 +230,10 @@ impl Attr {
         })?);
         let span = span_map.span_for_range(range);
         let input = if let Some(ast::Expr::Literal(lit)) = ast.expr() {
-            let value = match lit.kind() {
+            Some(Interned::new(AttrInput::Literal(tt::Literal {
-                ast::LiteralKind::String(string) => string.value()?.into(),
+                text: lit.token().text().into(),
-                _ => lit.syntax().first_token()?.text().trim_matches('"').into(),
+                span,
-            };
+            })))
-            Some(Interned::new(AttrInput::Literal(value)))
         } else if let Some(tt) = ast.token_tree() {
             let tree = syntax_node_to_token_tree(tt.syntax(), span_map, span);
             Some(Interned::new(AttrInput::TokenTree(Box::new(tree))))
@@ -245,9 +266,8 @@ impl Attr {
             }
             Some(tt::TokenTree::Leaf(tt::Leaf::Punct(tt::Punct { char: '=', .. }))) => {
                 let input = match input.get(1) {
-                    Some(tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal { text, .. }))) => {
+                    Some(tt::TokenTree::Leaf(tt::Leaf::Literal(lit))) => {
-                        //FIXME the trimming here isn't quite right, raw strings are not handled
+                        Some(Interned::new(AttrInput::Literal(lit.clone())))
-                        Some(Interned::new(AttrInput::Literal(text.trim_matches('"').into())))
                     }
                     _ => None,
                 };
@@ -265,9 +285,14 @@ impl Attr {
 
 impl Attr {
     /// #[path = "string"]
-    pub fn string_value(&self) -> Option<&SmolStr> {
+    pub fn string_value(&self) -> Option<&str> {
         match self.input.as_deref()? {
-            AttrInput::Literal(it) => Some(it),
+            AttrInput::Literal(it) => match it.text.strip_prefix('r') {
+                Some(it) => it.trim_matches('#'),
+                None => it.text.as_str(),
+            }
+            .strip_prefix('"')?
+            .strip_suffix('"'),
             _ => None,
         }
     }

src/tools/rust-analyzer/crates/hir-expand/src/builtin_fn_macro.rs

@@ -1,11 +1,11 @@
 //! Builtin macro
 
-use base_db::{AnchoredPath, Edition, FileId};
+use base_db::{AnchoredPath, FileId};
 use cfg::CfgExpr;
 use either::Either;
 use itertools::Itertools;
 use mbe::{parse_exprs_with_sep, parse_to_token_tree};
-use span::{Span, SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
+use span::{Edition, Span, SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
 use syntax::ast::{self, AstToken};
 
 use crate::{

src/tools/rust-analyzer/crates/hir-expand/src/cfg_process.rs

@@ -10,7 +10,7 @@ use syntax::{
 use tracing::{debug, warn};
 use tt::SmolStr;
 
-use crate::{db::ExpandDatabase, MacroCallKind, MacroCallLoc};
+use crate::{db::ExpandDatabase, proc_macro::ProcMacroKind, MacroCallLoc, MacroDefKind};
 
 fn check_cfg_attr(attr: &Attr, loc: &MacroCallLoc, db: &dyn ExpandDatabase) -> Option<bool> {
     if !attr.simple_name().as_deref().map(|v| v == "cfg")? {
@@ -139,7 +139,7 @@ fn process_enum(
     'variant: for variant in variants.variants() {
         for attr in variant.attrs() {
             if check_cfg_attr(&attr, loc, db).map(|enabled| !enabled).unwrap_or_default() {
-                // Rustc does not strip the attribute if it is enabled. So we will will leave it
+                // Rustc does not strip the attribute if it is enabled. So we will leave it
                 debug!("censoring type {:?}", variant.syntax());
                 remove.insert(variant.syntax().clone().into());
                 // We need to remove the , as well
@@ -180,7 +180,13 @@ pub(crate) fn process_cfg_attrs(
     db: &dyn ExpandDatabase,
 ) -> Option<FxHashSet<SyntaxElement>> {
     // FIXME: #[cfg_eval] is not implemented. But it is not stable yet
-    if !matches!(loc.kind, MacroCallKind::Derive { .. }) {
+    let is_derive = match loc.def.kind {
+        MacroDefKind::BuiltInDerive(..)
+        | MacroDefKind::ProcMacro(_, ProcMacroKind::CustomDerive, _) => true,
+        MacroDefKind::BuiltInAttr(expander, _) => expander.is_derive(),
+        _ => false,
+    };
+    if !is_derive {
         return None;
     }
     let mut remove = FxHashSet::default();

src/tools/rust-analyzer/crates/hir-expand/src/db.rs

@@ -24,7 +24,8 @@ use crate::{
     HirFileId, HirFileIdRepr, MacroCallId, MacroCallKind, MacroCallLoc, MacroDefId, MacroDefKind,
     MacroFileId,
 };
-
+/// This is just to ensure the types of smart_macro_arg and macro_arg are the same
+type MacroArgResult = (Arc<tt::Subtree>, SyntaxFixupUndoInfo, Span);
 /// Total limit on the number of tokens produced by any macro invocation.
 ///
 /// If an invocation produces more tokens than this limit, it will not be stored in the database and
@@ -98,7 +99,13 @@ pub trait ExpandDatabase: SourceDatabase {
     /// Lowers syntactic macro call to a token tree representation. That's a firewall
     /// query, only typing in the macro call itself changes the returned
     /// subtree.
-    fn macro_arg(&self, id: MacroCallId) -> (Arc<tt::Subtree>, SyntaxFixupUndoInfo, Span);
+    fn macro_arg(&self, id: MacroCallId) -> MacroArgResult;
+    #[salsa::transparent]
+    fn macro_arg_considering_derives(
+        &self,
+        id: MacroCallId,
+        kind: &MacroCallKind,
+    ) -> MacroArgResult;
     /// Fetches the expander for this macro.
     #[salsa::transparent]
     #[salsa::invoke(TokenExpander::macro_expander)]
@@ -144,7 +151,7 @@ pub fn expand_speculative(
     let span_map = RealSpanMap::absolute(FileId::BOGUS);
     let span_map = SpanMapRef::RealSpanMap(&span_map);
 
-    let (_, _, span) = db.macro_arg(actual_macro_call);
+    let (_, _, span) = db.macro_arg_considering_derives(actual_macro_call, &loc.kind);
 
     // Build the subtree and token mapping for the speculative args
     let (mut tt, undo_info) = match loc.kind {
@@ -339,12 +346,24 @@ pub(crate) fn parse_with_map(
     }
 }
 
-// FIXME: for derive attributes, this will return separate copies of the same structures! Though
+/// This resolves the [MacroCallId] to check if it is a derive macro if so get the [macro_arg] for the derive.
-// they may differ in spans due to differing call sites...
+/// Other wise return the [macro_arg] for the macro_call_id.
-fn macro_arg(
+///
+/// This is not connected to the database so it does not cached the result. However, the inner [macro_arg] query is
+fn macro_arg_considering_derives(
     db: &dyn ExpandDatabase,
     id: MacroCallId,
-) -> (Arc<tt::Subtree>, SyntaxFixupUndoInfo, Span) {
+    kind: &MacroCallKind,
+) -> MacroArgResult {
+    match kind {
+        // Get the macro arg for the derive macro
+        MacroCallKind::Derive { derive_macro_id, .. } => db.macro_arg(*derive_macro_id),
+        // Normal macro arg
+        _ => db.macro_arg(id),
+    }
+}
+
+fn macro_arg(db: &dyn ExpandDatabase, id: MacroCallId) -> MacroArgResult {
     let loc = db.lookup_intern_macro_call(id);
 
     if let MacroCallLoc {
@@ -414,29 +433,30 @@ fn macro_arg(
             }
             return (Arc::new(tt), SyntaxFixupUndoInfo::NONE, span);
         }
-        MacroCallKind::Derive { ast_id, derive_attr_index, .. } => {
+        // MacroCallKind::Derive should not be here. As we are getting the argument for the derive macro
-            let node = ast_id.to_ptr(db).to_node(&root);
+        MacroCallKind::Derive { .. } => {
-            let censor_derive_input = censor_derive_input(derive_attr_index, &node);
+            unreachable!("`ExpandDatabase::macro_arg` called with `MacroCallKind::Derive`")
-            let item_node = node.into();
-            let attr_source = attr_source(derive_attr_index, &item_node);
-            // FIXME: This is wrong, this should point to the path of the derive attribute`
-            let span =
-                map.span_for_range(attr_source.as_ref().and_then(|it| it.path()).map_or_else(
-                    || item_node.syntax().text_range(),
-                    |it| it.syntax().text_range(),
-                ));
-            (censor_derive_input, item_node, span)
         }
         MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
             let node = ast_id.to_ptr(db).to_node(&root);
             let attr_source = attr_source(invoc_attr_index, &node);
+
             let span = map.span_for_range(
                 attr_source
                     .as_ref()
                     .and_then(|it| it.path())
                     .map_or_else(|| node.syntax().text_range(), |it| it.syntax().text_range()),
             );
-            (attr_source.into_iter().map(|it| it.syntax().clone().into()).collect(), node, span)
+            // If derive attribute we need to censor the derive input
+            if matches!(loc.def.kind, MacroDefKind::BuiltInAttr(expander, ..) if expander.is_derive())
+                && ast::Adt::can_cast(node.syntax().kind())
+            {
+                let adt = ast::Adt::cast(node.syntax().clone()).unwrap();
+                let censor_derive_input = censor_derive_input(invoc_attr_index, &adt);
+                (censor_derive_input, node, span)
+            } else {
+                (attr_source.into_iter().map(|it| it.syntax().clone().into()).collect(), node, span)
+            }
         }
     };
 
@@ -526,7 +546,8 @@ fn macro_expand(
     let (ExpandResult { value: tt, err }, span) = match loc.def.kind {
         MacroDefKind::ProcMacro(..) => return db.expand_proc_macro(macro_call_id).map(CowArc::Arc),
         _ => {
-            let (macro_arg, undo_info, span) = db.macro_arg(macro_call_id);
+            let (macro_arg, undo_info, span) =
+                db.macro_arg_considering_derives(macro_call_id, &loc.kind);
 
             let arg = &*macro_arg;
             let res =
@@ -603,7 +624,7 @@ fn proc_macro_span(db: &dyn ExpandDatabase, ast: AstId<ast::Fn>) -> Span {
 
 fn expand_proc_macro(db: &dyn ExpandDatabase, id: MacroCallId) -> ExpandResult<Arc<tt::Subtree>> {
     let loc = db.lookup_intern_macro_call(id);
-    let (macro_arg, undo_info, span) = db.macro_arg(id);
+    let (macro_arg, undo_info, span) = db.macro_arg_considering_derives(id, &loc.kind);
 
     let (expander, ast) = match loc.def.kind {
         MacroDefKind::ProcMacro(expander, _, ast) => (expander, ast),

src/tools/rust-analyzer/crates/hir-expand/src/declarative.rs

@@ -1,8 +1,8 @@
 //! Compiled declarative macro expanders (`macro_rules!`` and `macro`)
 use std::sync::OnceLock;
 
-use base_db::{CrateId, Edition, VersionReq};
+use base_db::{CrateId, VersionReq};
-use span::{MacroCallId, Span};
+use span::{MacroCallId, Span, SyntaxContextId};
 use syntax::{ast, AstNode};
 use triomphe::Arc;
 
@@ -10,13 +10,13 @@ use crate::{
     attrs::RawAttrs,
     db::ExpandDatabase,
     hygiene::{apply_mark, Transparency},
-    tt, AstId, ExpandError, ExpandResult,
+    tt, AstId, ExpandError, ExpandResult, Lookup,
 };
 
 /// Old-style `macro_rules` or the new macros 2.0
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct DeclarativeMacroExpander {
-    pub mac: mbe::DeclarativeMacro<span::Span>,
+    pub mac: mbe::DeclarativeMacro,
     pub transparency: Transparency,
 }
 
@@ -94,8 +94,6 @@ impl DeclarativeMacroExpander {
         def_crate: CrateId,
         id: AstId<ast::Macro>,
     ) -> Arc<DeclarativeMacroExpander> {
-        let crate_data = &db.crate_graph()[def_crate];
-        let is_2021 = crate_data.edition >= Edition::Edition2021;
         let (root, map) = crate::db::parse_with_map(db, id.file_id);
         let root = root.syntax_node();
 
@@ -133,6 +131,16 @@ impl DeclarativeMacroExpander {
             )
         });
 
+        let edition = |ctx: SyntaxContextId| {
+            let crate_graph = db.crate_graph();
+            if ctx.is_root() {
+                crate_graph[def_crate].edition
+            } else {
+                let data = db.lookup_intern_syntax_context(ctx);
+                // UNWRAP-SAFETY: Only the root context has no outer expansion
+                crate_graph[data.outer_expn.unwrap().lookup(db).def.krate].edition
+            }
+        };
         let (mac, transparency) = match id.to_ptr(db).to_node(&root) {
             ast::Macro::MacroRules(macro_rules) => (
                 match macro_rules.token_tree() {
@@ -145,12 +153,11 @@ impl DeclarativeMacroExpander {
                             ),
                         );
 
-                        mbe::DeclarativeMacro::parse_macro_rules(&tt, is_2021, new_meta_vars)
+                        mbe::DeclarativeMacro::parse_macro_rules(&tt, edition, new_meta_vars)
                     }
-                    None => mbe::DeclarativeMacro::from_err(
+                    None => mbe::DeclarativeMacro::from_err(mbe::ParseError::Expected(
-                        mbe::ParseError::Expected("expected a token tree".into()),
+                        "expected a token tree".into(),
-                        is_2021,
+                    )),
-                    ),
                 },
                 transparency(&macro_rules).unwrap_or(Transparency::SemiTransparent),
             ),
@@ -163,12 +170,11 @@ impl DeclarativeMacroExpander {
                             map.span_for_range(macro_def.macro_token().unwrap().text_range()),
                         );
 
-                        mbe::DeclarativeMacro::parse_macro2(&tt, is_2021, new_meta_vars)
+                        mbe::DeclarativeMacro::parse_macro2(&tt, edition, new_meta_vars)
                     }
-                    None => mbe::DeclarativeMacro::from_err(
+                    None => mbe::DeclarativeMacro::from_err(mbe::ParseError::Expected(
-                        mbe::ParseError::Expected("expected a token tree".into()),
+                        "expected a token tree".into(),
-                        is_2021,
+                    )),
-                    ),
                 },
                 transparency(&macro_def).unwrap_or(Transparency::Opaque),
             ),

src/tools/rust-analyzer/crates/hir-expand/src/lib.rs

@@ -30,10 +30,11 @@ use triomphe::Arc;
 
 use std::{fmt, hash::Hash};
 
-use base_db::{salsa::impl_intern_value_trivial, CrateId, Edition, FileId};
+use base_db::{salsa::impl_intern_value_trivial, CrateId, FileId};
 use either::Either;
 use span::{
-    ErasedFileAstId, FileRange, HirFileIdRepr, Span, SpanAnchor, SyntaxContextData, SyntaxContextId,
+    Edition, ErasedFileAstId, FileRange, HirFileIdRepr, Span, SpanAnchor, SyntaxContextData,
+    SyntaxContextId,
 };
 use syntax::{
     ast::{self, AstNode},
@@ -53,11 +54,9 @@ use crate::{
 
 pub use crate::files::{AstId, ErasedAstId, InFile, InMacroFile, InRealFile};
 
-pub use mbe::ValueResult;
+pub use mbe::{DeclarativeMacro, ValueResult};
 pub use span::{HirFileId, MacroCallId, MacroFileId};
 
-pub type DeclarativeMacro = ::mbe::DeclarativeMacro<tt::Span>;
-
 pub mod tt {
     pub use span::Span;
     pub use tt::{DelimiterKind, Spacing};
@@ -201,7 +200,7 @@ pub struct EagerCallInfo {
     /// Call id of the eager macro's input file (this is the macro file for its fully expanded input).
     arg_id: MacroCallId,
     error: Option<ExpandError>,
-    /// TODO: Doc
+    /// The call site span of the eager macro
     span: Span,
 }
 
@@ -212,7 +211,7 @@ pub enum MacroCallKind {
         expand_to: ExpandTo,
         /// Some if this is a macro call for an eager macro. Note that this is `None`
         /// for the eager input macro file.
-        // FIXME: This is being interned, subtrees can vary quickly differ just slightly causing
+        // FIXME: This is being interned, subtrees can vary quickly differing just slightly causing
         // leakage problems here
         eager: Option<Arc<EagerCallInfo>>,
     },
@@ -225,6 +224,9 @@ pub enum MacroCallKind {
         derive_attr_index: AttrId,
         /// Index of the derive macro in the derive attribute
         derive_index: u32,
+        /// The "parent" macro call.
+        /// We will resolve the same token tree for all derive macros in the same derive attribute.
+        derive_macro_id: MacroCallId,
     },
     Attr {
         ast_id: AstId<ast::Item>,
@@ -484,7 +486,7 @@ impl MacroDefId {
         matches!(
             self.kind,
             MacroDefKind::BuiltIn(..)
-                | MacroDefKind::ProcMacro(_, ProcMacroKind::FuncLike, _)
+                | MacroDefKind::ProcMacro(_, ProcMacroKind::Bang, _)
                 | MacroDefKind::BuiltInEager(..)
                 | MacroDefKind::Declarative(..)
         )
@@ -806,7 +808,8 @@ impl ExpansionInfo {
         let (parse, exp_map) = db.parse_macro_expansion(macro_file).value;
         let expanded = InMacroFile { file_id: macro_file, value: parse.syntax_node() };
 
-        let (macro_arg, _, _) = db.macro_arg(macro_file.macro_call_id);
+        let (macro_arg, _, _) =
+            db.macro_arg_considering_derives(macro_file.macro_call_id, &loc.kind);
 
         let def = loc.def.ast_id().left().and_then(|id| {
             let def_tt = match id.to_node(db) {

src/tools/rust-analyzer/crates/hir-expand/src/mod_path.rs

@@ -225,6 +225,26 @@ fn convert_path(
     let mut segments = path.segments();
 
     let segment = &segments.next()?;
+    let handle_super_kw = &mut |init_deg| {
+        let mut deg = init_deg;
+        let mut next_segment = None;
+        for segment in segments.by_ref() {
+            match segment.kind()? {
+                ast::PathSegmentKind::SuperKw => deg += 1,
+                ast::PathSegmentKind::Name(name) => {
+                    next_segment = Some(name.as_name());
+                    break;
+                }
+                ast::PathSegmentKind::Type { .. }
+                | ast::PathSegmentKind::SelfTypeKw
+                | ast::PathSegmentKind::SelfKw
+                | ast::PathSegmentKind::CrateKw => return None,
+            }
+        }
+
+        Some(ModPath::from_segments(PathKind::Super(deg), next_segment))
+    };
+
     let mut mod_path = match segment.kind()? {
         ast::PathSegmentKind::Name(name_ref) => {
             if name_ref.text() == "$crate" {
@@ -245,26 +265,8 @@ fn convert_path(
             ModPath::from_segments(PathKind::Plain, Some(known::SELF_TYPE))
         }
         ast::PathSegmentKind::CrateKw => ModPath::from_segments(PathKind::Crate, iter::empty()),
-        ast::PathSegmentKind::SelfKw => ModPath::from_segments(PathKind::Super(0), iter::empty()),
+        ast::PathSegmentKind::SelfKw => handle_super_kw(0)?,
-        ast::PathSegmentKind::SuperKw => {
+        ast::PathSegmentKind::SuperKw => handle_super_kw(1)?,
-            let mut deg = 1;
-            let mut next_segment = None;
-            for segment in segments.by_ref() {
-                match segment.kind()? {
-                    ast::PathSegmentKind::SuperKw => deg += 1,
-                    ast::PathSegmentKind::Name(name) => {
-                        next_segment = Some(name.as_name());
-                        break;
-                    }
-                    ast::PathSegmentKind::Type { .. }
-                    | ast::PathSegmentKind::SelfTypeKw
-                    | ast::PathSegmentKind::SelfKw
-                    | ast::PathSegmentKind::CrateKw => return None,
-                }
-            }
-
-            ModPath::from_segments(PathKind::Super(deg), next_segment)
-        }
         ast::PathSegmentKind::Type { .. } => {
             // not allowed in imports
             return None;

src/tools/rust-analyzer/crates/hir-expand/src/proc_macro.rs

@@ -23,7 +23,7 @@ impl ProcMacroId {
 #[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
 pub enum ProcMacroKind {
     CustomDerive,
-    FuncLike,
+    Bang,
     Attr,
 }
 

src/tools/rust-analyzer/crates/hir-ty/Cargo.toml

@@ -47,13 +47,14 @@ hir-expand.workspace = true
 base-db.workspace = true
 syntax.workspace = true
 limit.workspace = true
+span.workspace = true
 
 [dev-dependencies]
 expect-test = "1.4.0"
 tracing.workspace = true
 tracing-subscriber.workspace = true
 tracing-tree.workspace = true
-project-model = { path = "../project-model" }
+project-model.workspace = true
 
 # local deps
 test-utils.workspace = true

src/tools/rust-analyzer/crates/hir-ty/src/builder.rs

@@ -9,21 +9,21 @@ use chalk_ir::{
     AdtId, DebruijnIndex, Scalar,
 };
 use hir_def::{
-    builtin_type::BuiltinType, generics::TypeOrConstParamData, ConstParamId, DefWithBodyId,
+    builtin_type::BuiltinType, DefWithBodyId, GenericDefId, GenericParamId, TraitId, TypeAliasId,
-    GenericDefId, TraitId, TypeAliasId,
 };
 use smallvec::SmallVec;
 
 use crate::{
-    consteval::unknown_const_as_generic, db::HirDatabase, infer::unify::InferenceTable, primitive,
+    consteval::unknown_const_as_generic, db::HirDatabase, error_lifetime,
-    to_assoc_type_id, to_chalk_trait_id, utils::generics, Binders, BoundVar, CallableSig,
+    infer::unify::InferenceTable, primitive, to_assoc_type_id, to_chalk_trait_id, utils::generics,
-    GenericArg, GenericArgData, Interner, ProjectionTy, Substitution, TraitRef, Ty, TyDefId, TyExt,
+    Binders, BoundVar, CallableSig, GenericArg, GenericArgData, Interner, ProjectionTy,
-    TyKind,
+    Substitution, TraitRef, Ty, TyDefId, TyExt, TyKind,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ParamKind {
     Type,
+    Lifetime,
     Const(Ty),
 }
 
@@ -107,6 +107,9 @@ impl<D> TyBuilder<D> {
             ParamKind::Const(ty) => {
                 BoundVar::new(debruijn, idx).to_const(Interner, ty.clone()).cast(Interner)
             }
+            ParamKind::Lifetime => {
+                BoundVar::new(debruijn, idx).to_lifetime(Interner).cast(Interner)
+            }
         });
         this.vec.extend(filler.take(this.remaining()).casted(Interner));
         assert_eq!(this.remaining(), 0);
@@ -119,6 +122,7 @@ impl<D> TyBuilder<D> {
         let filler = this.param_kinds[this.vec.len()..].iter().map(|x| match x {
             ParamKind::Type => TyKind::Error.intern(Interner).cast(Interner),
             ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+            ParamKind::Lifetime => error_lifetime().cast(Interner),
         });
         this.vec.extend(filler.casted(Interner));
         assert_eq!(this.remaining(), 0);
@@ -130,6 +134,7 @@ impl<D> TyBuilder<D> {
         self.fill(|x| match x {
             ParamKind::Type => table.new_type_var().cast(Interner),
             ParamKind::Const(ty) => table.new_const_var(ty.clone()).cast(Interner),
+            ParamKind::Lifetime => table.new_lifetime_var().cast(Interner),
         })
     }
 
@@ -142,7 +147,8 @@ impl<D> TyBuilder<D> {
     fn assert_match_kind(&self, a: &chalk_ir::GenericArg<Interner>, e: &ParamKind) {
         match (a.data(Interner), e) {
             (GenericArgData::Ty(_), ParamKind::Type)
-            | (GenericArgData::Const(_), ParamKind::Const(_)) => (),
+            | (GenericArgData::Const(_), ParamKind::Const(_))
+            | (GenericArgData::Lifetime(_), ParamKind::Lifetime) => (),
             _ => panic!("Mismatched kinds: {a:?}, {:?}, {:?}", self.vec, self.param_kinds),
         }
     }
@@ -201,10 +207,11 @@ impl TyBuilder<()> {
         Substitution::from_iter(
             Interner,
             params.iter_id().map(|id| match id {
-                either::Either::Left(_) => TyKind::Error.intern(Interner).cast(Interner),
+                GenericParamId::TypeParamId(_) => TyKind::Error.intern(Interner).cast(Interner),
-                either::Either::Right(id) => {
+                GenericParamId::ConstParamId(id) => {
                     unknown_const_as_generic(db.const_param_ty(id)).cast(Interner)
                 }
+                GenericParamId::LifetimeParamId(_) => error_lifetime().cast(Interner),
             }),
         )
     }
@@ -219,11 +226,10 @@ impl TyBuilder<()> {
         assert!(generics.parent_generics().is_some() == parent_subst.is_some());
         let params = generics
             .iter_self()
-            .map(|(id, data)| match data {
+            .map(|(id, _data)| match id {
-                TypeOrConstParamData::TypeParamData(_) => ParamKind::Type,
+                GenericParamId::TypeParamId(_) => ParamKind::Type,
-                TypeOrConstParamData::ConstParamData(_) => {
+                GenericParamId::ConstParamId(id) => ParamKind::Const(db.const_param_ty(id)),
-                    ParamKind::Const(db.const_param_ty(ConstParamId::from_unchecked(id)))
+                GenericParamId::LifetimeParamId(_) => ParamKind::Lifetime,
-                }
             })
             .collect();
         TyBuilder::new((), params, parent_subst)

src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs

@@ -272,6 +272,19 @@ impl chalk_solve::RustIrDatabase<Interner> for ChalkContext<'_> {
                 };
                 chalk_ir::Binders::new(binders, bound)
             }
+            crate::ImplTraitId::AssociatedTypeImplTrait(alias, idx) => {
+                let datas = self
+                    .db
+                    .type_alias_impl_traits(alias)
+                    .expect("impl trait id without impl traits");
+                let (datas, binders) = (*datas).as_ref().into_value_and_skipped_binders();
+                let data = &datas.impl_traits[idx];
+                let bound = OpaqueTyDatumBound {
+                    bounds: make_single_type_binders(data.bounds.skip_binders().to_vec()),
+                    where_clauses: chalk_ir::Binders::empty(Interner, vec![]),
+                };
+                chalk_ir::Binders::new(binders, bound)
+            }
             crate::ImplTraitId::AsyncBlockTypeImplTrait(..) => {
                 if let Some((future_trait, future_output)) = self
                     .db

src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs

@@ -268,6 +268,13 @@ impl TyExt for Ty {
                             data.substitute(Interner, &subst).into_value_and_skipped_binders().0
                         })
                     }
+                    ImplTraitId::AssociatedTypeImplTrait(alias, idx) => {
+                        db.type_alias_impl_traits(alias).map(|it| {
+                            let data =
+                                (*it).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
+                            data.substitute(Interner, &subst).into_value_and_skipped_binders().0
+                        })
+                    }
                 }
             }
             TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
@@ -280,6 +287,13 @@ impl TyExt for Ty {
                             data.substitute(Interner, &opaque_ty.substitution)
                         })
                     }
+                    ImplTraitId::AssociatedTypeImplTrait(alias, idx) => {
+                        db.type_alias_impl_traits(alias).map(|it| {
+                            let data =
+                                (*it).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
+                            data.substitute(Interner, &opaque_ty.substitution)
+                        })
+                    }
                     // It always has an parameter for Future::Output type.
                     ImplTraitId::AsyncBlockTypeImplTrait(..) => unreachable!(),
                 };

src/tools/rust-analyzer/crates/hir-ty/src/consteval/tests.rs

@@ -2825,3 +2825,30 @@ fn unsized_local() {
         |e| matches!(e, ConstEvalError::MirLowerError(MirLowerError::UnsizedTemporary(_))),
     );
 }
+
+#[test]
+fn recursive_adt() {
+    check_fail(
+        r#"
+        //- minicore: coerce_unsized, index, slice
+        pub enum TagTree {
+            Leaf,
+            Choice(&'static [TagTree]),
+        }
+        const GOAL: TagTree = {
+            const TAG_TREE: TagTree = TagTree::Choice(&[
+                {
+                    const VARIANT_TAG_TREE: TagTree = TagTree::Choice(
+                        &[
+                            TagTree::Leaf,
+                        ],
+                    );
+                    VARIANT_TAG_TREE
+                },
+            ]);
+            TAG_TREE
+        };
+    "#,
+        |e| matches!(e, ConstEvalError::MirEvalError(MirEvalError::StackOverflow)),
+    );
+}

src/tools/rust-analyzer/crates/hir-ty/src/db.rs

@@ -11,7 +11,7 @@ use base_db::{
 use hir_def::{
     db::DefDatabase, hir::ExprId, layout::TargetDataLayout, AdtId, BlockId, ConstParamId,
     DefWithBodyId, EnumVariantId, FunctionId, GeneralConstId, GenericDefId, ImplId,
-    LifetimeParamId, LocalFieldId, StaticId, TypeOrConstParamId, VariantId,
+    LifetimeParamId, LocalFieldId, StaticId, TypeAliasId, TypeOrConstParamId, VariantId,
 };
 use la_arena::ArenaMap;
 use smallvec::SmallVec;
@@ -23,9 +23,9 @@ use crate::{
     layout::{Layout, LayoutError},
     method_resolution::{InherentImpls, TraitImpls, TyFingerprint},
     mir::{BorrowckResult, MirBody, MirLowerError},
-    Binders, CallableDefId, ClosureId, Const, FnDefId, GenericArg, ImplTraitId, InferenceResult,
+    Binders, CallableDefId, ClosureId, Const, FnDefId, GenericArg, ImplTraitId, ImplTraits,
-    Interner, PolyFnSig, QuantifiedWhereClause, ReturnTypeImplTraits, Substitution,
+    InferenceResult, Interner, PolyFnSig, QuantifiedWhereClause, Substitution, TraitEnvironment,
-    TraitEnvironment, TraitRef, Ty, TyDefId, ValueTyDefId,
+    TraitRef, Ty, TyDefId, ValueTyDefId,
 };
 use hir_expand::name::Name;
 
@@ -132,10 +132,10 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     fn callable_item_signature(&self, def: CallableDefId) -> PolyFnSig;
 
     #[salsa::invoke(crate::lower::return_type_impl_traits)]
-    fn return_type_impl_traits(
+    fn return_type_impl_traits(&self, def: FunctionId) -> Option<Arc<Binders<ImplTraits>>>;
-        &self,
+
-        def: FunctionId,
+    #[salsa::invoke(crate::lower::type_alias_impl_traits)]
-    ) -> Option<Arc<Binders<ReturnTypeImplTraits>>>;
+    fn type_alias_impl_traits(&self, def: TypeAliasId) -> Option<Arc<Binders<ImplTraits>>>;
 
     #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
     #[salsa::cycle(crate::lower::generic_predicates_for_param_recover)]

src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/expr.rs

@@ -11,7 +11,6 @@ use hir_def::{ItemContainerId, Lookup};
 use hir_expand::name;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
-use rustc_pattern_analysis::usefulness::{compute_match_usefulness, ValidityConstraint};
 use syntax::{ast, AstNode};
 use tracing::debug;
 use triomphe::Arc;
@@ -234,13 +233,7 @@ impl ExprValidator {
             return;
         }
 
-        let report = match compute_match_usefulness(
+        let report = match cx.compute_match_usefulness(m_arms.as_slice(), scrut_ty.clone()) {
-            &cx,
-            m_arms.as_slice(),
-            scrut_ty.clone(),
-            ValidityConstraint::ValidOnly,
-            None,
-        ) {
             Ok(report) => report,
             Err(()) => return,
         };
@@ -282,13 +275,7 @@ impl ExprValidator {
                 continue;
             }
 
-            let report = match compute_match_usefulness(
+            let report = match cx.compute_match_usefulness(&[match_arm], ty.clone()) {
-                &cx,
-                &[match_arm],
-                ty.clone(),
-                ValidityConstraint::ValidOnly,
-                None,
-            ) {
                 Ok(v) => v,
                 Err(e) => {
                     debug!(?e, "match usefulness error");

src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs

@@ -8,7 +8,8 @@ use rustc_hash::FxHashMap;
 use rustc_pattern_analysis::{
     constructor::{Constructor, ConstructorSet, VariantVisibility},
     index::IdxContainer,
-    Captures, PrivateUninhabitedField, TypeCx,
+    usefulness::{compute_match_usefulness, PlaceValidity, UsefulnessReport},
+    Captures, PatCx, PrivateUninhabitedField,
 };
 use smallvec::{smallvec, SmallVec};
 use stdx::never;
@@ -59,6 +60,18 @@ impl<'p> MatchCheckCtx<'p> {
         Self { module, body, db, exhaustive_patterns, min_exhaustive_patterns }
     }
 
+    pub(crate) fn compute_match_usefulness(
+        &self,
+        arms: &[MatchArm<'p>],
+        scrut_ty: Ty,
+    ) -> Result<UsefulnessReport<'p, Self>, ()> {
+        // FIXME: Determine place validity correctly. For now, err on the safe side.
+        let place_validity = PlaceValidity::MaybeInvalid;
+        // Measured to take ~100ms on modern hardware.
+        let complexity_limit = Some(500000);
+        compute_match_usefulness(self, arms, scrut_ty, place_validity, complexity_limit)
+    }
+
     fn is_uninhabited(&self, ty: &Ty) -> bool {
         is_ty_uninhabited_from(ty, self.module, self.db)
     }
@@ -107,15 +120,17 @@ impl<'p> MatchCheckCtx<'p> {
     }
 
     pub(crate) fn lower_pat(&self, pat: &Pat) -> DeconstructedPat<'p> {
-        let singleton = |pat| vec![pat];
+        let singleton = |pat: DeconstructedPat<'p>| vec![pat.at_index(0)];
         let ctor;
-        let fields: Vec<_>;
+        let mut fields: Vec<_>;
+        let arity;
 
         match pat.kind.as_ref() {
             PatKind::Binding { subpattern: Some(subpat), .. } => return self.lower_pat(subpat),
             PatKind::Binding { subpattern: None, .. } | PatKind::Wild => {
                 ctor = Wildcard;
                 fields = Vec::new();
+                arity = 0;
             }
             PatKind::Deref { subpattern } => {
                 ctor = match pat.ty.kind(Interner) {
@@ -128,23 +143,22 @@ impl<'p> MatchCheckCtx<'p> {
                     }
                 };
                 fields = singleton(self.lower_pat(subpattern));
+                arity = 1;
             }
             PatKind::Leaf { subpatterns } | PatKind::Variant { subpatterns, .. } => {
+                fields = subpatterns
+                    .iter()
+                    .map(|pat| {
+                        let idx: u32 = pat.field.into_raw().into();
+                        self.lower_pat(&pat.pattern).at_index(idx as usize)
+                    })
+                    .collect();
                 match pat.ty.kind(Interner) {
                     TyKind::Tuple(_, substs) => {
                         ctor = Struct;
-                        let mut wilds: Vec<_> = substs
+                        arity = substs.len(Interner);
-                            .iter(Interner)
-                            .map(|arg| arg.assert_ty_ref(Interner).clone())
-                            .map(DeconstructedPat::wildcard)
-                            .collect();
-                        for pat in subpatterns {
-                            let idx: u32 = pat.field.into_raw().into();
-                            wilds[idx as usize] = self.lower_pat(&pat.pattern);
-                        }
-                        fields = wilds
                     }
-                    TyKind::Adt(adt, substs) if is_box(self.db, adt.0) => {
+                    TyKind::Adt(adt, _) if is_box(self.db, adt.0) => {
                         // The only legal patterns of type `Box` (outside `std`) are `_` and box
                         // patterns. If we're here we can assume this is a box pattern.
                         // FIXME(Nadrieril): A `Box` can in theory be matched either with `Box(_,
@@ -157,16 +171,9 @@ impl<'p> MatchCheckCtx<'p> {
                         // normally or through box-patterns. We'll have to figure out a proper
                         // solution when we introduce generalized deref patterns. Also need to
                         // prevent mixing of those two options.
-                        let pat =
+                        fields.retain(|ipat| ipat.idx == 0);
-                            subpatterns.iter().find(|pat| pat.field.into_raw() == 0u32.into());
-                        let field = if let Some(pat) = pat {
-                            self.lower_pat(&pat.pattern)
-                        } else {
-                            let ty = substs.at(Interner, 0).assert_ty_ref(Interner).clone();
-                            DeconstructedPat::wildcard(ty)
-                        };
                         ctor = Struct;
-                        fields = singleton(field);
+                        arity = 1;
                     }
                     &TyKind::Adt(adt, _) => {
                         ctor = match pat.kind.as_ref() {
@@ -181,37 +188,33 @@ impl<'p> MatchCheckCtx<'p> {
                             }
                         };
                         let variant = Self::variant_id_for_adt(&ctor, adt.0).unwrap();
-                        // Fill a vec with wildcards, then place the fields we have at the right
+                        arity = variant.variant_data(self.db.upcast()).fields().len();
-                        // index.
-                        let mut wilds: Vec<_> = self
-                            .list_variant_fields(&pat.ty, variant)
-                            .map(|(_, ty)| ty)
-                            .map(DeconstructedPat::wildcard)
-                            .collect();
-                        for pat in subpatterns {
-                            let field_id: u32 = pat.field.into_raw().into();
-                            wilds[field_id as usize] = self.lower_pat(&pat.pattern);
-                        }
-                        fields = wilds;
                     }
                     _ => {
                         never!("pattern has unexpected type: pat: {:?}, ty: {:?}", pat, &pat.ty);
                         ctor = Wildcard;
-                        fields = Vec::new();
+                        fields.clear();
+                        arity = 0;
                     }
                 }
             }
             &PatKind::LiteralBool { value } => {
                 ctor = Bool(value);
                 fields = Vec::new();
+                arity = 0;
             }
             PatKind::Or { pats } => {
                 ctor = Or;
-                fields = pats.iter().map(|pat| self.lower_pat(pat)).collect();
+                fields = pats
+                    .iter()
+                    .enumerate()
+                    .map(|(i, pat)| self.lower_pat(pat).at_index(i))
+                    .collect();
+                arity = pats.len();
             }
         }
         let data = PatData { db: self.db };
-        DeconstructedPat::new(ctor, fields, pat.ty.clone(), data)
+        DeconstructedPat::new(ctor, fields, arity, pat.ty.clone(), data)
     }
 
     pub(crate) fn hoist_witness_pat(&self, pat: &WitnessPat<'p>) -> Pat {
@@ -271,7 +274,7 @@ impl<'p> MatchCheckCtx<'p> {
     }
 }
 
-impl<'p> TypeCx for MatchCheckCtx<'p> {
+impl<'p> PatCx for MatchCheckCtx<'p> {
     type Error = ();
     type Ty = Ty;
     type VariantIdx = EnumVariantId;
@@ -453,7 +456,7 @@ impl<'p> TypeCx for MatchCheckCtx<'p> {
         let variant =
             pat.ty().as_adt().and_then(|(adt, _)| Self::variant_id_for_adt(pat.ctor(), adt));
 
-        let db = pat.data().unwrap().db;
+        let db = pat.data().db;
         if let Some(variant) = variant {
             match variant {
                 VariantId::EnumVariantId(v) => {
@@ -475,7 +478,6 @@ impl<'p> TypeCx for MatchCheckCtx<'p> {
     }
 
     fn complexity_exceeded(&self) -> Result<(), Self::Error> {
-        // FIXME(Nadrieril): make use of the complexity counter.
         Err(())
     }
 }

src/tools/rust-analyzer/crates/hir-ty/src/display.rs

@@ -938,18 +938,32 @@ impl HirDisplay for Ty {
                 f.end_location_link();
                 if parameters.len(Interner) > 0 {
                     let generics = generics(db.upcast(), def.into());
-                    let (parent_params, self_param, type_params, const_params, _impl_trait_params) =
+                    let (
-                        generics.provenance_split();
+                        parent_params,
-                    let total_len = parent_params + self_param + type_params + const_params;
+                        self_param,
+                        type_params,
+                        const_params,
+                        _impl_trait_params,
+                        lifetime_params,
+                    ) = generics.provenance_split();
+                    let total_len =
+                        parent_params + self_param + type_params + const_params + lifetime_params;
                     // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
                     if total_len > 0 {
-                        // `parameters` are in the order of fn's params (including impl traits),
+                        // `parameters` are in the order of fn's params (including impl traits), fn's lifetimes
                         // parent's params (those from enclosing impl or trait, if any).
                         let parameters = parameters.as_slice(Interner);
                         let fn_params_len = self_param + type_params + const_params;
+                        // This will give slice till last type or const
                         let fn_params = parameters.get(..fn_params_len);
+                        let fn_lt_params =
+                            parameters.get(fn_params_len..(fn_params_len + lifetime_params));
                         let parent_params = parameters.get(parameters.len() - parent_params..);
-                        let params = parent_params.into_iter().chain(fn_params).flatten();
+                        let params = parent_params
+                            .into_iter()
+                            .chain(fn_lt_params)
+                            .chain(fn_params)
+                            .flatten();
                         write!(f, "<")?;
                         f.write_joined(params, ", ")?;
                         write!(f, ">")?;
@@ -1063,6 +1077,20 @@ impl HirDisplay for Ty {
                         )?;
                         // FIXME: it would maybe be good to distinguish this from the alias type (when debug printing), and to show the substitution
                     }
+                    ImplTraitId::AssociatedTypeImplTrait(alias, idx) => {
+                        let datas =
+                            db.type_alias_impl_traits(alias).expect("impl trait id without data");
+                        let data =
+                            (*datas).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
+                        let bounds = data.substitute(Interner, &parameters);
+                        let krate = alias.krate(db.upcast());
+                        write_bounds_like_dyn_trait_with_prefix(
+                            f,
+                            "impl",
+                            bounds.skip_binders(),
+                            SizedByDefault::Sized { anchor: krate },
+                        )?;
+                    }
                     ImplTraitId::AsyncBlockTypeImplTrait(body, ..) => {
                         let future_trait = db
                             .lang_item(body.module(db.upcast()).krate(), LangItem::Future)
@@ -1228,6 +1256,20 @@ impl HirDisplay for Ty {
                             SizedByDefault::Sized { anchor: krate },
                         )?;
                     }
+                    ImplTraitId::AssociatedTypeImplTrait(alias, idx) => {
+                        let datas =
+                            db.type_alias_impl_traits(alias).expect("impl trait id without data");
+                        let data =
+                            (*datas).as_ref().map(|rpit| rpit.impl_traits[idx].bounds.clone());
+                        let bounds = data.substitute(Interner, &opaque_ty.substitution);
+                        let krate = alias.krate(db.upcast());
+                        write_bounds_like_dyn_trait_with_prefix(
+                            f,
+                            "impl",
+                            bounds.skip_binders(),
+                            SizedByDefault::Sized { anchor: krate },
+                        )?;
+                    }
                     ImplTraitId::AsyncBlockTypeImplTrait(..) => {
                         write!(f, "{{async block}}")?;
                     }
@@ -1280,8 +1322,17 @@ fn hir_fmt_generics(
     generic_def: Option<hir_def::GenericDefId>,
 ) -> Result<(), HirDisplayError> {
     let db = f.db;
-    let lifetime_args_count = generic_def.map_or(0, |g| db.generic_params(g).lifetimes.len());
+    if parameters.len(Interner) > 0 {
-    if parameters.len(Interner) + lifetime_args_count > 0 {
+        use std::cmp::Ordering;
+        let param_compare =
+            |a: &GenericArg, b: &GenericArg| match (a.data(Interner), b.data(Interner)) {
+                (crate::GenericArgData::Lifetime(_), crate::GenericArgData::Lifetime(_)) => {
+                    Ordering::Equal
+                }
+                (crate::GenericArgData::Lifetime(_), _) => Ordering::Less,
+                (_, crate::GenericArgData::Lifetime(_)) => Ordering::Less,
+                (_, _) => Ordering::Equal,
+            };
         let parameters_to_write = if f.display_target.is_source_code() || f.omit_verbose_types() {
             match generic_def
                 .map(|generic_def_id| db.generic_defaults(generic_def_id))
@@ -1307,6 +1358,11 @@ fn hir_fmt_generics(
                                 return true;
                             }
                         }
+                        if parameter.lifetime(Interner).map(|it| it.data(Interner))
+                            == Some(&crate::LifetimeData::Static)
+                        {
+                            return true;
+                        }
                         let default_parameter = match default_parameters.get(i) {
                             Some(it) => it,
                             None => return true,
@@ -1327,16 +1383,12 @@ fn hir_fmt_generics(
         } else {
             parameters.as_slice(Interner)
         };
-        if !parameters_to_write.is_empty() || lifetime_args_count != 0 {
+        //FIXME: Should handle the ordering of lifetimes when creating substitutions
+        let mut parameters_to_write = parameters_to_write.to_vec();
+        parameters_to_write.sort_by(param_compare);
+        if !parameters_to_write.is_empty() {
             write!(f, "<")?;
             let mut first = true;
-            for _ in 0..lifetime_args_count {
-                if !first {
-                    write!(f, ", ")?;
-                }
-                first = false;
-                write!(f, "'_")?;
-            }
             for generic_arg in parameters_to_write {
                 if !first {
                     write!(f, ", ")?;

src/tools/rust-analyzer/crates/hir-ty/src/infer.rs

@@ -25,8 +25,11 @@ pub(crate) mod unify;
 use std::{convert::identity, iter, ops::Index};
 
 use chalk_ir::{
-    cast::Cast, fold::TypeFoldable, interner::HasInterner, DebruijnIndex, Mutability, Safety,
+    cast::Cast,
-    Scalar, TyKind, TypeFlags, Variance,
+    fold::TypeFoldable,
+    interner::HasInterner,
+    visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor},
+    DebruijnIndex, Mutability, Safety, Scalar, TyKind, TypeFlags, Variance,
 };
 use either::Either;
 use hir_def::{
@@ -39,7 +42,7 @@ use hir_def::{
     layout::Integer,
     path::{ModPath, Path},
     resolver::{HasResolver, ResolveValueResult, Resolver, TypeNs, ValueNs},
-    type_ref::TypeRef,
+    type_ref::{LifetimeRef, TypeRef},
     AdtId, AssocItemId, DefWithBodyId, FieldId, FunctionId, ItemContainerId, Lookup, TraitId,
     TupleFieldId, TupleId, TypeAliasId, VariantId,
 };
@@ -53,14 +56,14 @@ use triomphe::Arc;
 use crate::{
     db::HirDatabase,
     fold_tys,
-    infer::coerce::CoerceMany,
+    infer::{coerce::CoerceMany, unify::InferenceTable},
     lower::ImplTraitLoweringMode,
     static_lifetime, to_assoc_type_id,
     traits::FnTrait,
     utils::{InTypeConstIdMetadata, UnevaluatedConstEvaluatorFolder},
     AliasEq, AliasTy, Binders, ClosureId, Const, DomainGoal, GenericArg, Goal, ImplTraitId,
-    InEnvironment, Interner, Lifetime, ProjectionTy, RpitId, Substitution, TraitEnvironment,
+    ImplTraitIdx, InEnvironment, Interner, Lifetime, OpaqueTyId, ProjectionTy, Substitution,
-    TraitRef, Ty, TyBuilder, TyExt,
+    TraitEnvironment, Ty, TyBuilder, TyExt,
 };
 
 // This lint has a false positive here. See the link below for details.
@@ -422,7 +425,7 @@ pub struct InferenceResult {
     /// unresolved or missing subpatterns or subpatterns of mismatched types.
     pub type_of_pat: ArenaMap<PatId, Ty>,
     pub type_of_binding: ArenaMap<BindingId, Ty>,
-    pub type_of_rpit: ArenaMap<RpitId, Ty>,
+    pub type_of_rpit: ArenaMap<ImplTraitIdx, Ty>,
     /// Type of the result of `.into_iter()` on the for. `ExprId` is the one of the whole for loop.
     pub type_of_for_iterator: FxHashMap<ExprId, Ty>,
     type_mismatches: FxHashMap<ExprOrPatId, TypeMismatch>,
@@ -752,7 +755,12 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn collect_const(&mut self, data: &ConstData) {
-        self.return_ty = self.make_ty(&data.type_ref);
+        let return_ty = self.make_ty(&data.type_ref);
+
+        // Constants might be associated items that define ATPITs.
+        self.insert_atpit_coercion_table(iter::once(&return_ty));
+
+        self.return_ty = return_ty;
     }
 
     fn collect_static(&mut self, data: &StaticData) {
@@ -785,11 +793,13 @@ impl<'a> InferenceContext<'a> {
                 self.write_binding_ty(self_param, ty);
             }
         }
+        let mut params_and_ret_tys = Vec::new();
         for (ty, pat) in param_tys.zip(&*self.body.params) {
             let ty = self.insert_type_vars(ty);
             let ty = self.normalize_associated_types_in(ty);
 
             self.infer_top_pat(*pat, &ty);
+            params_and_ret_tys.push(ty);
         }
         let return_ty = &*data.ret_type;
 
@@ -801,8 +811,11 @@ impl<'a> InferenceContext<'a> {
         let return_ty = if let Some(rpits) = self.db.return_type_impl_traits(func) {
             // RPIT opaque types use substitution of their parent function.
             let fn_placeholders = TyBuilder::placeholder_subst(self.db, func);
-            let result =
+            let result = self.insert_inference_vars_for_impl_trait(
-                self.insert_inference_vars_for_rpit(return_ty, rpits.clone(), fn_placeholders);
+                return_ty,
+                rpits.clone(),
+                fn_placeholders,
+            );
             let rpits = rpits.skip_binders();
             for (id, _) in rpits.impl_traits.iter() {
                 if let Entry::Vacant(e) = self.result.type_of_rpit.entry(id) {
@@ -817,13 +830,19 @@ impl<'a> InferenceContext<'a> {
 
         self.return_ty = self.normalize_associated_types_in(return_ty);
         self.return_coercion = Some(CoerceMany::new(self.return_ty.clone()));
+
+        // Functions might be associated items that define ATPITs.
+        // To define an ATPITs, that ATPIT must appear in the function's signatures.
+        // So, it suffices to check for params and return types.
+        params_and_ret_tys.push(self.return_ty.clone());
+        self.insert_atpit_coercion_table(params_and_ret_tys.iter());
     }
 
-    fn insert_inference_vars_for_rpit<T>(
+    fn insert_inference_vars_for_impl_trait<T>(
         &mut self,
         t: T,
-        rpits: Arc<chalk_ir::Binders<crate::ReturnTypeImplTraits>>,
+        rpits: Arc<chalk_ir::Binders<crate::ImplTraits>>,
-        fn_placeholders: Substitution,
+        placeholders: Substitution,
     ) -> T
     where
         T: crate::HasInterner<Interner = Interner> + crate::TypeFoldable<Interner>,
@@ -837,6 +856,7 @@ impl<'a> InferenceContext<'a> {
                 };
                 let idx = match self.db.lookup_intern_impl_trait_id(opaque_ty_id.into()) {
                     ImplTraitId::ReturnTypeImplTrait(_, idx) => idx,
+                    ImplTraitId::AssociatedTypeImplTrait(_, idx) => idx,
                     _ => unreachable!(),
                 };
                 let bounds =
@@ -844,15 +864,14 @@ impl<'a> InferenceContext<'a> {
                 let var = self.table.new_type_var();
                 let var_subst = Substitution::from1(Interner, var.clone());
                 for bound in bounds {
-                    let predicate =
+                    let predicate = bound.map(|it| it.cloned()).substitute(Interner, &placeholders);
-                        bound.map(|it| it.cloned()).substitute(Interner, &fn_placeholders);
                     let (var_predicate, binders) =
                         predicate.substitute(Interner, &var_subst).into_value_and_skipped_binders();
                     always!(binders.is_empty(Interner)); // quantified where clauses not yet handled
-                    let var_predicate = self.insert_inference_vars_for_rpit(
+                    let var_predicate = self.insert_inference_vars_for_impl_trait(
                         var_predicate,
                         rpits.clone(),
-                        fn_placeholders.clone(),
+                        placeholders.clone(),
                     );
                     self.push_obligation(var_predicate.cast(Interner));
                 }
@@ -863,6 +882,106 @@ impl<'a> InferenceContext<'a> {
         )
     }
 
+    /// The coercion of a non-inference var into an opaque type should fail,
+    /// but not in the defining sites of the ATPITs.
+    /// In such cases, we insert an proxy inference var for each ATPIT,
+    /// and coerce into it instead of ATPIT itself.
+    ///
+    /// The inference var stretagy is effective because;
+    ///
+    /// - It can still unify types that coerced into ATPIT
+    /// - We are pushing `impl Trait` bounds into it
+    ///
+    /// This function inserts a map that maps the opaque type to that proxy inference var.
+    fn insert_atpit_coercion_table<'b>(&mut self, tys: impl Iterator<Item = &'b Ty>) {
+        struct OpaqueTyCollector<'a, 'b> {
+            table: &'b mut InferenceTable<'a>,
+            opaque_tys: FxHashMap<OpaqueTyId, Ty>,
+        }
+
+        impl<'a, 'b> TypeVisitor<Interner> for OpaqueTyCollector<'a, 'b> {
+            type BreakTy = ();
+
+            fn as_dyn(&mut self) -> &mut dyn TypeVisitor<Interner, BreakTy = Self::BreakTy> {
+                self
+            }
+
+            fn interner(&self) -> Interner {
+                Interner
+            }
+
+            fn visit_ty(
+                &mut self,
+                ty: &chalk_ir::Ty<Interner>,
+                outer_binder: DebruijnIndex,
+            ) -> std::ops::ControlFlow<Self::BreakTy> {
+                let ty = self.table.resolve_ty_shallow(ty);
+
+                if let TyKind::OpaqueType(id, _) = ty.kind(Interner) {
+                    self.opaque_tys.insert(*id, ty.clone());
+                }
+
+                ty.super_visit_with(self, outer_binder)
+            }
+        }
+
+        // Early return if this is not happening inside the impl block
+        let impl_id = if let Some(impl_id) = self.resolver.impl_def() {
+            impl_id
+        } else {
+            return;
+        };
+
+        let assoc_tys: FxHashSet<_> = self
+            .db
+            .impl_data(impl_id)
+            .items
+            .iter()
+            .filter_map(|item| match item {
+                AssocItemId::TypeAliasId(alias) => Some(*alias),
+                _ => None,
+            })
+            .collect();
+        if assoc_tys.is_empty() {
+            return;
+        }
+
+        let mut collector =
+            OpaqueTyCollector { table: &mut self.table, opaque_tys: FxHashMap::default() };
+        for ty in tys {
+            ty.visit_with(collector.as_dyn(), DebruijnIndex::INNERMOST);
+        }
+        let atpit_coercion_table: FxHashMap<_, _> = collector
+            .opaque_tys
+            .into_iter()
+            .filter_map(|(opaque_ty_id, ty)| {
+                if let ImplTraitId::AssociatedTypeImplTrait(alias_id, _) =
+                    self.db.lookup_intern_impl_trait_id(opaque_ty_id.into())
+                {
+                    if assoc_tys.contains(&alias_id) {
+                        let atpits = self
+                            .db
+                            .type_alias_impl_traits(alias_id)
+                            .expect("Marked as ATPIT but no impl traits!");
+                        let alias_placeholders = TyBuilder::placeholder_subst(self.db, alias_id);
+                        let ty = self.insert_inference_vars_for_impl_trait(
+                            ty,
+                            atpits,
+                            alias_placeholders,
+                        );
+                        return Some((opaque_ty_id, ty));
+                    }
+                }
+
+                None
+            })
+            .collect();
+
+        if !atpit_coercion_table.is_empty() {
+            self.table.atpit_coercion_table = Some(atpit_coercion_table);
+        }
+    }
+
     fn infer_body(&mut self) {
         match self.return_coercion {
             Some(_) => self.infer_return(self.body.body_expr),
@@ -918,6 +1037,12 @@ impl<'a> InferenceContext<'a> {
         self.result.standard_types.unknown.clone()
     }
 
+    fn make_lifetime(&mut self, lifetime_ref: &LifetimeRef) -> Lifetime {
+        let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver, self.owner.into());
+        let lt = ctx.lower_lifetime(lifetime_ref);
+        self.insert_type_vars(lt)
+    }
+
     /// Replaces `Ty::Error` by a new type var, so we can maybe still infer it.
     fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
         self.table.insert_type_vars_shallow(ty)

src/tools/rust-analyzer/crates/hir-ty/src/infer/coerce.rs

@@ -276,6 +276,23 @@ impl InferenceTable<'_> {
             return success(simple(Adjust::NeverToAny)(to_ty.clone()), to_ty.clone(), vec![]);
         }
 
+        // If we are coercing into an ATPIT, coerce into its proxy inference var, instead.
+        let mut to_ty = to_ty;
+        let _to;
+        if let Some(atpit_table) = &self.atpit_coercion_table {
+            if let TyKind::OpaqueType(opaque_ty_id, _) = to_ty.kind(Interner) {
+                if !matches!(
+                    from_ty.kind(Interner),
+                    TyKind::InferenceVar(..) | TyKind::OpaqueType(..)
+                ) {
+                    if let Some(ty) = atpit_table.get(opaque_ty_id) {
+                        _to = ty.clone();
+                        to_ty = &_to;
+                    }
+                }
+            }
+        }
+
         // Consider coercing the subtype to a DST
         if let Ok(ret) = self.try_coerce_unsized(&from_ty, to_ty) {
             return Ok(ret);

src/tools/rust-analyzer/crates/hir-ty/src/infer/expr.rs

@@ -8,13 +8,12 @@ use std::{
 use chalk_ir::{cast::Cast, fold::Shift, DebruijnIndex, Mutability, TyVariableKind};
 use either::Either;
 use hir_def::{
-    generics::TypeOrConstParamData,
     hir::{
         ArithOp, Array, BinaryOp, ClosureKind, Expr, ExprId, LabelId, Literal, Statement, UnaryOp,
     },
     lang_item::{LangItem, LangItemTarget},
-    path::{GenericArg, GenericArgs, Path},
+    path::{GenericArgs, Path},
-    BlockId, ConstParamId, FieldId, ItemContainerId, Lookup, TupleFieldId, TupleId,
+    BlockId, FieldId, GenericParamId, ItemContainerId, Lookup, TupleFieldId, TupleId,
 };
 use hir_expand::name::{name, Name};
 use stdx::always;
@@ -1816,10 +1815,17 @@ impl InferenceContext<'_> {
         def_generics: Generics,
         generic_args: Option<&GenericArgs>,
     ) -> Substitution {
-        let (parent_params, self_params, type_params, const_params, impl_trait_params) =
+        let (
-            def_generics.provenance_split();
+            parent_params,
+            self_params,
+            type_params,
+            const_params,
+            impl_trait_params,
+            lifetime_params,
+        ) = def_generics.provenance_split();
         assert_eq!(self_params, 0); // method shouldn't have another Self param
-        let total_len = parent_params + type_params + const_params + impl_trait_params;
+        let total_len =
+            parent_params + type_params + const_params + impl_trait_params + lifetime_params;
         let mut substs = Vec::with_capacity(total_len);
 
         // handle provided arguments
@@ -1828,8 +1834,7 @@ impl InferenceContext<'_> {
             for (arg, kind_id) in generic_args
                 .args
                 .iter()
-                .filter(|arg| !matches!(arg, GenericArg::Lifetime(_)))
+                .take(type_params + const_params + lifetime_params)
-                .take(type_params + const_params)
                 .zip(def_generics.iter_id())
             {
                 if let Some(g) = generic_arg_to_chalk(
@@ -1850,6 +1855,7 @@ impl InferenceContext<'_> {
                             DebruijnIndex::INNERMOST,
                         )
                     },
+                    |this, lt_ref| this.make_lifetime(lt_ref),
                 ) {
                     substs.push(g);
                 }
@@ -1858,16 +1864,17 @@ impl InferenceContext<'_> {
 
         // Handle everything else as unknown. This also handles generic arguments for the method's
         // parent (impl or trait), which should come after those for the method.
-        for (id, data) in def_generics.iter().skip(substs.len()) {
+        for (id, _data) in def_generics.iter().skip(substs.len()) {
-            match data {
+            match id {
-                TypeOrConstParamData::TypeParamData(_) => {
+                GenericParamId::TypeParamId(_) => {
                     substs.push(self.table.new_type_var().cast(Interner))
                 }
-                TypeOrConstParamData::ConstParamData(_) => substs.push(
+                GenericParamId::ConstParamId(id) => {
-                    self.table
+                    substs.push(self.table.new_const_var(self.db.const_param_ty(id)).cast(Interner))
-                        .new_const_var(self.db.const_param_ty(ConstParamId::from_unchecked(id)))
+                }
-                        .cast(Interner),
+                GenericParamId::LifetimeParamId(_) => {
-                ),
+                    substs.push(self.table.new_lifetime_var().cast(Interner))
+                }
             }
         }
         assert_eq!(substs.len(), total_len);

src/tools/rust-analyzer/crates/hir-ty/src/infer/path.rs

@@ -11,15 +11,15 @@ use stdx::never;
 
 use crate::{
     builder::ParamKind,
-    consteval,
+    consteval, error_lifetime,
     method_resolution::{self, VisibleFromModule},
     to_chalk_trait_id,
     utils::generics,
-    InferenceDiagnostic, Interner, Substitution, TraitRefExt, Ty, TyBuilder, TyExt, TyKind,
+    InferenceDiagnostic, Interner, Substitution, TraitRef, TraitRefExt, Ty, TyBuilder, TyExt,
-    ValueTyDefId,
+    TyKind, ValueTyDefId,
 };
 
-use super::{ExprOrPatId, InferenceContext, TraitRef};
+use super::{ExprOrPatId, InferenceContext};
 
 impl InferenceContext<'_> {
     pub(super) fn infer_path(&mut self, path: &Path, id: ExprOrPatId) -> Option<Ty> {
@@ -111,6 +111,7 @@ impl InferenceContext<'_> {
                 it.next().unwrap_or_else(|| match x {
                     ParamKind::Type => self.result.standard_types.unknown.clone().cast(Interner),
                     ParamKind::Const(ty) => consteval::unknown_const_as_generic(ty.clone()),
+                    ParamKind::Lifetime => error_lifetime().cast(Interner),
                 })
             })
             .build();

src/tools/rust-analyzer/crates/hir-ty/src/infer/unify.rs

@@ -10,16 +10,18 @@ use chalk_solve::infer::ParameterEnaVariableExt;
 use either::Either;
 use ena::unify::UnifyKey;
 use hir_expand::name;
+use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use triomphe::Arc;
 
 use super::{InferOk, InferResult, InferenceContext, TypeError};
 use crate::{
-    consteval::unknown_const, db::HirDatabase, fold_tys_and_consts, static_lifetime,
+    consteval::unknown_const, db::HirDatabase, fold_generic_args, fold_tys_and_consts,
-    to_chalk_trait_id, traits::FnTrait, AliasEq, AliasTy, BoundVar, Canonical, Const, ConstValue,
+    static_lifetime, to_chalk_trait_id, traits::FnTrait, AliasEq, AliasTy, BoundVar, Canonical,
-    DebruijnIndex, DomainGoal, GenericArg, GenericArgData, Goal, GoalData, Guidance, InEnvironment,
+    Const, ConstValue, DebruijnIndex, DomainGoal, GenericArg, GenericArgData, Goal, GoalData,
-    InferenceVar, Interner, Lifetime, ParamKind, ProjectionTy, ProjectionTyExt, Scalar, Solution,
+    Guidance, InEnvironment, InferenceVar, Interner, Lifetime, OpaqueTyId, ParamKind, ProjectionTy,
-    Substitution, TraitEnvironment, Ty, TyBuilder, TyExt, TyKind, VariableKind, WhereClause,
+    ProjectionTyExt, Scalar, Solution, Substitution, TraitEnvironment, Ty, TyBuilder, TyExt,
+    TyKind, VariableKind, WhereClause,
 };
 
 impl InferenceContext<'_> {
@@ -239,6 +241,7 @@ type ChalkInferenceTable = chalk_solve::infer::InferenceTable<Interner>;
 pub(crate) struct InferenceTable<'a> {
     pub(crate) db: &'a dyn HirDatabase,
     pub(crate) trait_env: Arc<TraitEnvironment>,
+    pub(crate) atpit_coercion_table: Option<FxHashMap<OpaqueTyId, Ty>>,
     var_unification_table: ChalkInferenceTable,
     type_variable_table: SmallVec<[TypeVariableFlags; 16]>,
     pending_obligations: Vec<Canonicalized<InEnvironment<Goal>>>,
@@ -258,6 +261,7 @@ impl<'a> InferenceTable<'a> {
         InferenceTable {
             db,
             trait_env,
+            atpit_coercion_table: None,
             var_unification_table: ChalkInferenceTable::new(),
             type_variable_table: SmallVec::new(),
             pending_obligations: Vec::new(),
@@ -803,6 +807,7 @@ impl<'a> InferenceTable<'a> {
             .fill(|it| {
                 let arg = match it {
                     ParamKind::Type => self.new_type_var(),
+                    ParamKind::Lifetime => unreachable!("Tuple with lifetime parameter"),
                     ParamKind::Const(_) => unreachable!("Tuple with const parameter"),
                 };
                 arg_tys.push(arg.clone());
@@ -857,11 +862,16 @@ impl<'a> InferenceTable<'a> {
     where
         T: HasInterner<Interner = Interner> + TypeFoldable<Interner>,
     {
-        fold_tys_and_consts(
+        fold_generic_args(
             ty,
-            |it, _| match it {
+            |arg, _| match arg {
-                Either::Left(ty) => Either::Left(self.insert_type_vars_shallow(ty)),
+                GenericArgData::Ty(ty) => GenericArgData::Ty(self.insert_type_vars_shallow(ty)),
-                Either::Right(c) => Either::Right(self.insert_const_vars_shallow(c)),
+                // FIXME: insert lifetime vars once LifetimeData::InferenceVar
+                // and specific error variant for lifetimes start being constructed
+                GenericArgData::Lifetime(lt) => GenericArgData::Lifetime(lt),
+                GenericArgData::Const(c) => {
+                    GenericArgData::Const(self.insert_const_vars_shallow(c))
+                }
             },
             DebruijnIndex::INNERMOST,
         )

src/tools/rust-analyzer/crates/hir-ty/src/layout.rs

@@ -389,6 +389,9 @@ pub fn layout_of_ty_query(
                     let infer = db.infer(func.into());
                     return db.layout_of_ty(infer.type_of_rpit[idx].clone(), trait_env);
                 }
+                crate::ImplTraitId::AssociatedTypeImplTrait(..) => {
+                    return Err(LayoutError::NotImplemented);
+                }
                 crate::ImplTraitId::AsyncBlockTypeImplTrait(_, _) => {
                     return Err(LayoutError::NotImplemented)
                 }

src/tools/rust-analyzer/crates/hir-ty/src/lib.rs

@@ -15,7 +15,8 @@ extern crate rustc_abi;
 #[cfg(not(feature = "in-rust-tree"))]
 extern crate ra_ap_rustc_abi as rustc_abi;
 
-// No need to use the in-tree one.
+// Use the crates.io version unconditionally until the API settles enough that we can switch to
+// using the in-tree one.
 extern crate ra_ap_rustc_pattern_analysis as rustc_pattern_analysis;
 
 mod builder;
@@ -89,8 +90,8 @@ pub use lower::{
 };
 pub use mapping::{
     from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
-    lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
+    lt_from_placeholder_idx, lt_to_placeholder_idx, to_assoc_type_id, to_chalk_trait_id,
-    to_placeholder_idx,
+    to_foreign_def_id, to_placeholder_idx,
 };
 pub use method_resolution::check_orphan_rules;
 pub use traits::TraitEnvironment;
@@ -334,11 +335,23 @@ pub(crate) fn make_binders_with_count<T: HasInterner<Interner = Interner>>(
     generics: &Generics,
     value: T,
 ) -> Binders<T> {
-    let it = generics.iter_id().take(count).map(|id| match id {
+    let it = generics.iter_id().take(count);
-        Either::Left(_) => None,
+
-        Either::Right(id) => Some(db.const_param_ty(id)),
+    Binders::new(
-    });
+        VariableKinds::from_iter(
-    crate::make_type_and_const_binders(it, value)
+            Interner,
+            it.map(|x| match x {
+                hir_def::GenericParamId::ConstParamId(id) => {
+                    chalk_ir::VariableKind::Const(db.const_param_ty(id))
+                }
+                hir_def::GenericParamId::TypeParamId(_) => {
+                    chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
+                }
+                hir_def::GenericParamId::LifetimeParamId(_) => chalk_ir::VariableKind::Lifetime,
+            }),
+        ),
+        value,
+    )
 }
 
 pub(crate) fn make_binders<T: HasInterner<Interner = Interner>>(
@@ -584,29 +597,34 @@ impl TypeFoldable<Interner> for CallableSig {
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 pub enum ImplTraitId {
-    ReturnTypeImplTrait(hir_def::FunctionId, RpitId),
+    ReturnTypeImplTrait(hir_def::FunctionId, ImplTraitIdx),
+    AssociatedTypeImplTrait(hir_def::TypeAliasId, ImplTraitIdx),
     AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
 }
 impl_intern_value_trivial!(ImplTraitId);
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct ReturnTypeImplTraits {
+pub struct ImplTraits {
-    pub(crate) impl_traits: Arena<ReturnTypeImplTrait>,
+    pub(crate) impl_traits: Arena<ImplTrait>,
 }
 
-has_interner!(ReturnTypeImplTraits);
+has_interner!(ImplTraits);
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub struct ReturnTypeImplTrait {
+pub struct ImplTrait {
     pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
 }
 
-pub type RpitId = Idx<ReturnTypeImplTrait>;
+pub type ImplTraitIdx = Idx<ImplTrait>;
 
 pub fn static_lifetime() -> Lifetime {
     LifetimeData::Static.intern(Interner)
 }
 
+pub fn error_lifetime() -> Lifetime {
+    static_lifetime()
+}
+
 pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
     t: T,
     for_ty: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
@@ -696,6 +714,55 @@ pub(crate) fn fold_tys_and_consts<T: HasInterner<Interner = Interner> + TypeFold
     t.fold_with(&mut TyFolder(f), binders)
 }
 
+pub(crate) fn fold_generic_args<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
+    t: T,
+    f: impl FnMut(GenericArgData, DebruijnIndex) -> GenericArgData,
+    binders: DebruijnIndex,
+) -> T {
+    use chalk_ir::fold::{TypeFolder, TypeSuperFoldable};
+    #[derive(chalk_derive::FallibleTypeFolder)]
+    #[has_interner(Interner)]
+    struct TyFolder<F: FnMut(GenericArgData, DebruijnIndex) -> GenericArgData>(F);
+    impl<F: FnMut(GenericArgData, DebruijnIndex) -> GenericArgData> TypeFolder<Interner>
+        for TyFolder<F>
+    {
+        fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner> {
+            self
+        }
+
+        fn interner(&self) -> Interner {
+            Interner
+        }
+
+        fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Ty {
+            let ty = ty.super_fold_with(self.as_dyn(), outer_binder);
+            self.0(GenericArgData::Ty(ty), outer_binder)
+                .intern(Interner)
+                .ty(Interner)
+                .unwrap()
+                .clone()
+        }
+
+        fn fold_const(&mut self, c: Const, outer_binder: DebruijnIndex) -> Const {
+            self.0(GenericArgData::Const(c), outer_binder)
+                .intern(Interner)
+                .constant(Interner)
+                .unwrap()
+                .clone()
+        }
+
+        fn fold_lifetime(&mut self, lt: Lifetime, outer_binder: DebruijnIndex) -> Lifetime {
+            let lt = lt.super_fold_with(self.as_dyn(), outer_binder);
+            self.0(GenericArgData::Lifetime(lt), outer_binder)
+                .intern(Interner)
+                .lifetime(Interner)
+                .unwrap()
+                .clone()
+        }
+    }
+    t.fold_with(&mut TyFolder(f), binders)
+}
+
 /// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
 /// ensures there are no unbound variables or inference variables anywhere in
 /// the `t`.

src/tools/rust-analyzer/crates/hir-ty/src/lower.rs

@@ -24,17 +24,20 @@ use hir_def::{
     data::adt::StructKind,
     expander::Expander,
     generics::{
-        TypeOrConstParamData, TypeParamProvenance, WherePredicate, WherePredicateTypeTarget,
+        GenericParamDataRef, TypeOrConstParamData, TypeParamProvenance, WherePredicate,
+        WherePredicateTypeTarget,
     },
     lang_item::LangItem,
     nameres::MacroSubNs,
     path::{GenericArg, GenericArgs, ModPath, Path, PathKind, PathSegment, PathSegments},
-    resolver::{HasResolver, Resolver, TypeNs},
+    resolver::{HasResolver, LifetimeNs, Resolver, TypeNs},
-    type_ref::{ConstRef, TraitBoundModifier, TraitRef as HirTraitRef, TypeBound, TypeRef},
+    type_ref::{
+        ConstRef, LifetimeRef, TraitBoundModifier, TraitRef as HirTraitRef, TypeBound, TypeRef,
+    },
     AdtId, AssocItemId, ConstId, ConstParamId, DefWithBodyId, EnumId, EnumVariantId, FunctionId,
-    GenericDefId, HasModule, ImplId, InTypeConstLoc, ItemContainerId, LocalFieldId, Lookup,
+    GenericDefId, GenericParamId, HasModule, ImplId, InTypeConstLoc, ItemContainerId, LocalFieldId,
-    ModuleDefId, StaticId, StructId, TraitId, TypeAliasId, TypeOrConstParamId, TypeOwnerId,
+    Lookup, ModuleDefId, StaticId, StructId, TraitId, TypeAliasId, TypeOrConstParamId, TypeOwnerId,
-    TypeParamId, UnionId, VariantId,
+    UnionId, VariantId,
 };
 use hir_expand::{name::Name, ExpandResult};
 use intern::Interned;
@@ -52,18 +55,18 @@ use crate::{
         unknown_const_as_generic,
     },
     db::HirDatabase,
-    make_binders,
+    error_lifetime, make_binders,
-    mapping::{from_chalk_trait_id, ToChalk},
+    mapping::{from_chalk_trait_id, lt_to_placeholder_idx, ToChalk},
     static_lifetime, to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
-    utils::Generics,
     utils::{
-        all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
+        all_super_trait_refs, associated_type_by_name_including_super_traits, generics, Generics,
         InTypeConstIdMetadata,
     },
     AliasEq, AliasTy, Binders, BoundVar, CallableSig, Const, ConstScalar, DebruijnIndex, DynTy,
-    FnAbi, FnPointer, FnSig, FnSubst, ImplTraitId, Interner, ParamKind, PolyFnSig, ProjectionTy,
+    FnAbi, FnPointer, FnSig, FnSubst, ImplTrait, ImplTraitId, ImplTraits, Interner, Lifetime,
-    QuantifiedWhereClause, QuantifiedWhereClauses, ReturnTypeImplTrait, ReturnTypeImplTraits,
+    LifetimeData, ParamKind, PolyFnSig, ProjectionTy, QuantifiedWhereClause,
-    Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyKind, WhereClause,
+    QuantifiedWhereClauses, Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder,
+    TyKind, WhereClause,
 };
 
 #[derive(Debug)]
@@ -76,7 +79,7 @@ enum ImplTraitLoweringState {
     /// we're grouping the mutable data (the counter and this field) together
     /// with the immutable context (the references to the DB and resolver).
     /// Splitting this up would be a possible fix.
-    Opaque(RefCell<Arena<ReturnTypeImplTrait>>),
+    Opaque(RefCell<Arena<ImplTrait>>),
     Param(Cell<u16>),
     Variable(Cell<u16>),
     Disallowed,
@@ -275,9 +278,11 @@ impl<'a> TyLoweringContext<'a> {
                 let inner_ty = self.lower_ty(inner);
                 TyKind::Slice(inner_ty).intern(Interner)
             }
-            TypeRef::Reference(inner, _, mutability) => {
+            TypeRef::Reference(inner, lifetime, mutability) => {
                 let inner_ty = self.lower_ty(inner);
-                let lifetime = static_lifetime();
+                // FIXME: It should infer the eldided lifetimes instead of stubbing with static
+                let lifetime =
+                    lifetime.as_ref().map_or_else(static_lifetime, |lr| self.lower_lifetime(lr));
                 TyKind::Ref(lower_to_chalk_mutability(*mutability), lifetime, inner_ty)
                     .intern(Interner)
             }
@@ -301,15 +306,18 @@ impl<'a> TyLoweringContext<'a> {
             TypeRef::ImplTrait(bounds) => {
                 match &self.impl_trait_mode {
                     ImplTraitLoweringState::Opaque(opaque_type_data) => {
-                        let func = match self.resolver.generic_def() {
+                        let origin = match self.resolver.generic_def() {
-                            Some(GenericDefId::FunctionId(f)) => f,
+                            Some(GenericDefId::FunctionId(it)) => Either::Left(it),
-                            _ => panic!("opaque impl trait lowering in non-function"),
+                            Some(GenericDefId::TypeAliasId(it)) => Either::Right(it),
+                            _ => panic!(
+                                "opaque impl trait lowering must be in function or type alias"
+                            ),
                         };
 
                         // this dance is to make sure the data is in the right
                         // place even if we encounter more opaque types while
                         // lowering the bounds
-                        let idx = opaque_type_data.borrow_mut().alloc(ReturnTypeImplTrait {
+                        let idx = opaque_type_data.borrow_mut().alloc(ImplTrait {
                             bounds: crate::make_single_type_binders(Vec::new()),
                         });
                         // We don't want to lower the bounds inside the binders
@@ -323,13 +331,17 @@ impl<'a> TyLoweringContext<'a> {
                         // away instead of two.
                         let actual_opaque_type_data = self
                             .with_debruijn(DebruijnIndex::INNERMOST, |ctx| {
-                                ctx.lower_impl_trait(bounds, func)
+                                ctx.lower_impl_trait(bounds, self.resolver.krate())
                             });
                         opaque_type_data.borrow_mut()[idx] = actual_opaque_type_data;
 
-                        let impl_trait_id = ImplTraitId::ReturnTypeImplTrait(func, idx);
+                        let impl_trait_id = origin.either(
+                            |f| ImplTraitId::ReturnTypeImplTrait(f, idx),
+                            |a| ImplTraitId::AssociatedTypeImplTrait(a, idx),
+                        );
                         let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into();
-                        let generics = generics(self.db.upcast(), func.into());
+                        let generics =
+                            generics(self.db.upcast(), origin.either(|f| f.into(), |a| a.into()));
                         let parameters = generics.bound_vars_subst(self.db, self.in_binders);
                         TyKind::OpaqueType(opaque_ty_id, parameters).intern(Interner)
                     }
@@ -344,13 +356,18 @@ impl<'a> TyLoweringContext<'a> {
                                 .filter(|(_, data)| {
                                     matches!(
                                         data,
-                                        TypeOrConstParamData::TypeParamData(data)
+                                        GenericParamDataRef::TypeParamData(data)
                                         if data.provenance == TypeParamProvenance::ArgumentImplTrait
                                     )
                                 })
                                 .nth(idx as usize)
                                 .map_or(TyKind::Error, |(id, _)| {
-                                    TyKind::Placeholder(to_placeholder_idx(self.db, id))
+                                    if let GenericParamId::TypeParamId(id) = id {
+                                        TyKind::Placeholder(to_placeholder_idx(self.db, id.into()))
+                                    } else {
+                                        // we just filtered them out
+                                        unreachable!("Unexpected lifetime or const argument");
+                                    }
                                 });
                             param.intern(Interner)
                         } else {
@@ -367,11 +384,12 @@ impl<'a> TyLoweringContext<'a> {
                             list_params,
                             const_params,
                             _impl_trait_params,
+                            _lifetime_params,
                         ) = if let Some(def) = self.resolver.generic_def() {
                             let generics = generics(self.db.upcast(), def);
                             generics.provenance_split()
                         } else {
-                            (0, 0, 0, 0, 0)
+                            (0, 0, 0, 0, 0, 0)
                         };
                         TyKind::BoundVar(BoundVar::new(
                             self.in_binders,
@@ -808,9 +826,16 @@ impl<'a> TyLoweringContext<'a> {
             return Substitution::empty(Interner);
         };
         let def_generics = generics(self.db.upcast(), def);
-        let (parent_params, self_params, type_params, const_params, impl_trait_params) =
+        let (
-            def_generics.provenance_split();
+            parent_params,
-        let item_len = self_params + type_params + const_params + impl_trait_params;
+            self_params,
+            type_params,
+            const_params,
+            impl_trait_params,
+            lifetime_params,
+        ) = def_generics.provenance_split();
+        let item_len =
+            self_params + type_params + const_params + impl_trait_params + lifetime_params;
         let total_len = parent_params + item_len;
 
         let ty_error = TyKind::Error.intern(Interner).cast(Interner);
@@ -825,7 +850,10 @@ impl<'a> TyLoweringContext<'a> {
                 .take(self_params)
             {
                 if let Some(id) = def_generic_iter.next() {
-                    assert!(id.is_left());
+                    assert!(matches!(
+                        id,
+                        GenericParamId::TypeParamId(_) | GenericParamId::LifetimeParamId(_)
+                    ));
                     substs.push(x);
                 }
             }
@@ -858,6 +886,7 @@ impl<'a> TyLoweringContext<'a> {
                         &mut (),
                         |_, type_ref| self.lower_ty(type_ref),
                         |_, const_ref, ty| self.lower_const(const_ref, ty),
+                        |_, lifetime_ref| self.lower_lifetime(lifetime_ref),
                     ) {
                         had_explicit_args = true;
                         substs.push(x);
@@ -867,15 +896,45 @@ impl<'a> TyLoweringContext<'a> {
                     }
                 }
             }
+
+            for arg in generic_args
+                .args
+                .iter()
+                .filter(|arg| matches!(arg, GenericArg::Lifetime(_)))
+                .take(lifetime_params)
+            {
+                // Taking into the fact that def_generic_iter will always have lifetimes at the end
+                // Should have some test cases tho to test this behaviour more properly
+                if let Some(id) = def_generic_iter.next() {
+                    if let Some(x) = generic_arg_to_chalk(
+                        self.db,
+                        id,
+                        arg,
+                        &mut (),
+                        |_, type_ref| self.lower_ty(type_ref),
+                        |_, const_ref, ty| self.lower_const(const_ref, ty),
+                        |_, lifetime_ref| self.lower_lifetime(lifetime_ref),
+                    ) {
+                        had_explicit_args = true;
+                        substs.push(x);
+                    } else {
+                        // Never return a None explicitly
+                        never!("Unexpected None by generic_arg_to_chalk");
+                    }
+                }
+            }
         } else {
             fill_self_params();
         }
 
         // These params include those of parent.
         let remaining_params: SmallVec<[_; 2]> = def_generic_iter
-            .map(|eid| match eid {
+            .map(|id| match id {
-                Either::Left(_) => ty_error.clone(),
+                GenericParamId::ConstParamId(x) => {
-                Either::Right(x) => unknown_const_as_generic(self.db.const_param_ty(x)),
+                    unknown_const_as_generic(self.db.const_param_ty(x))
+                }
+                GenericParamId::TypeParamId(_) => ty_error.clone(),
+                GenericParamId::LifetimeParamId(_) => error_lifetime().cast(Interner),
             })
             .collect();
         assert_eq!(remaining_params.len() + substs.len(), total_len);
@@ -1107,8 +1166,12 @@ impl<'a> TyLoweringContext<'a> {
                     binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(),
                 );
                 if let Some(type_ref) = &binding.type_ref {
-                    if let (TypeRef::ImplTrait(bounds), ImplTraitLoweringState::Disallowed) =
+                    if let (
-                        (type_ref, &self.impl_trait_mode)
+                        TypeRef::ImplTrait(bounds),
+                        ImplTraitLoweringState::Param(_)
+                        | ImplTraitLoweringState::Variable(_)
+                        | ImplTraitLoweringState::Disallowed,
+                    ) = (type_ref, &self.impl_trait_mode)
                     {
                         for bound in bounds {
                             predicates.extend(
@@ -1270,11 +1333,7 @@ impl<'a> TyLoweringContext<'a> {
         }
     }
 
-    fn lower_impl_trait(
+    fn lower_impl_trait(&self, bounds: &[Interned<TypeBound>], krate: CrateId) -> ImplTrait {
-        &self,
-        bounds: &[Interned<TypeBound>],
-        func: FunctionId,
-    ) -> ReturnTypeImplTrait {
         cov_mark::hit!(lower_rpit);
         let self_ty = TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
         let predicates = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
@@ -1284,7 +1343,6 @@ impl<'a> TyLoweringContext<'a> {
                 .collect();
 
             if !ctx.unsized_types.borrow().contains(&self_ty) {
-                let krate = func.krate(ctx.db.upcast());
                 let sized_trait = ctx
                     .db
                     .lang_item(krate, LangItem::Sized)
@@ -1301,7 +1359,34 @@ impl<'a> TyLoweringContext<'a> {
             }
             predicates
         });
-        ReturnTypeImplTrait { bounds: crate::make_single_type_binders(predicates) }
+        ImplTrait { bounds: crate::make_single_type_binders(predicates) }
+    }
+
+    pub fn lower_lifetime(&self, lifetime: &LifetimeRef) -> Lifetime {
+        match self.resolver.resolve_lifetime(lifetime) {
+            Some(resolution) => match resolution {
+                LifetimeNs::Static => static_lifetime(),
+                LifetimeNs::LifetimeParam(id) => match self.type_param_mode {
+                    ParamLoweringMode::Placeholder => {
+                        LifetimeData::Placeholder(lt_to_placeholder_idx(self.db, id))
+                    }
+                    ParamLoweringMode::Variable => {
+                        let generics = generics(
+                            self.db.upcast(),
+                            self.resolver.generic_def().expect("generics in scope"),
+                        );
+                        let idx = match generics.lifetime_idx(id) {
+                            None => return error_lifetime(),
+                            Some(idx) => idx,
+                        };
+
+                        LifetimeData::BoundVar(BoundVar::new(self.in_binders, idx))
+                    }
+                }
+                .intern(Interner),
+            },
+            None => error_lifetime(),
+        }
     }
 }
 
@@ -1685,7 +1770,7 @@ pub(crate) fn generic_defaults_query(
 
     let defaults = Arc::from_iter(generic_params.iter().enumerate().map(|(idx, (id, p))| {
         match p {
-            TypeOrConstParamData::TypeParamData(p) => {
+            GenericParamDataRef::TypeParamData(p) => {
                 let mut ty =
                     p.default.as_ref().map_or(TyKind::Error.intern(Interner), |t| ctx.lower_ty(t));
                 // Each default can only refer to previous parameters.
@@ -1694,13 +1779,13 @@ pub(crate) fn generic_defaults_query(
                 ty = fallback_bound_vars(ty, idx, parent_start_idx);
                 crate::make_binders(db, &generic_params, ty.cast(Interner))
             }
-            TypeOrConstParamData::ConstParamData(p) => {
+            GenericParamDataRef::ConstParamData(p) => {
+                let GenericParamId::ConstParamId(id) = id else {
+                    unreachable!("Unexpected lifetime or type argument")
+                };
+
                 let mut val = p.default.as_ref().map_or_else(
-                    || {
+                    || unknown_const_as_generic(db.const_param_ty(id)),
-                        unknown_const_as_generic(
-                            db.const_param_ty(ConstParamId::from_unchecked(id)),
-                        )
-                    },
                     |c| {
                         let c = ctx.lower_const(c, ctx.lower_ty(&p.ty));
                         c.cast(Interner)
@@ -1710,6 +1795,10 @@ pub(crate) fn generic_defaults_query(
                 val = fallback_bound_vars(val, idx, parent_start_idx);
                 make_binders(db, &generic_params, val)
             }
+            GenericParamDataRef::LifetimeParamData(_) => {
+                // using static because it requires defaults
+                make_binders(db, &generic_params, static_lifetime().cast(Interner))
+            }
         }
     }));
 
@@ -1726,8 +1815,9 @@ pub(crate) fn generic_defaults_recover(
     // we still need one default per parameter
     let defaults = Arc::from_iter(generic_params.iter_id().map(|id| {
         let val = match id {
-            Either::Left(_) => TyKind::Error.intern(Interner).cast(Interner),
+            GenericParamId::TypeParamId(_) => TyKind::Error.intern(Interner).cast(Interner),
-            Either::Right(id) => unknown_const_as_generic(db.const_param_ty(id)),
+            GenericParamId::ConstParamId(id) => unknown_const_as_generic(db.const_param_ty(id)),
+            GenericParamId::LifetimeParamId(_) => static_lifetime().cast(Interner),
         };
         crate::make_binders(db, &generic_params, val)
     }));
@@ -1869,6 +1959,7 @@ fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
     let generics = generics(db.upcast(), t.into());
     let resolver = t.resolver(db.upcast());
     let ctx = TyLoweringContext::new(db, &resolver, t.into())
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
         .with_type_param_mode(ParamLoweringMode::Variable);
     let type_alias_data = db.type_alias_data(t);
     if type_alias_data.is_extern {
@@ -2029,7 +2120,7 @@ pub(crate) fn impl_trait_query(db: &dyn HirDatabase, impl_id: ImplId) -> Option<
 pub(crate) fn return_type_impl_traits(
     db: &dyn HirDatabase,
     def: hir_def::FunctionId,
-) -> Option<Arc<Binders<ReturnTypeImplTraits>>> {
+) -> Option<Arc<Binders<ImplTraits>>> {
     // FIXME unify with fn_sig_for_fn instead of doing lowering twice, maybe
     let data = db.function_data(def);
     let resolver = def.resolver(db.upcast());
@@ -2038,7 +2129,7 @@ pub(crate) fn return_type_impl_traits(
         .with_type_param_mode(ParamLoweringMode::Variable);
     let _ret = ctx_ret.lower_ty(&data.ret_type);
     let generics = generics(db.upcast(), def.into());
-    let return_type_impl_traits = ReturnTypeImplTraits {
+    let return_type_impl_traits = ImplTraits {
         impl_traits: match ctx_ret.impl_trait_mode {
             ImplTraitLoweringState::Opaque(x) => x.into_inner(),
             _ => unreachable!(),
@@ -2051,6 +2142,32 @@ pub(crate) fn return_type_impl_traits(
     }
 }
 
+pub(crate) fn type_alias_impl_traits(
+    db: &dyn HirDatabase,
+    def: hir_def::TypeAliasId,
+) -> Option<Arc<Binders<ImplTraits>>> {
+    let data = db.type_alias_data(def);
+    let resolver = def.resolver(db.upcast());
+    let ctx = TyLoweringContext::new(db, &resolver, def.into())
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
+        .with_type_param_mode(ParamLoweringMode::Variable);
+    if let Some(type_ref) = &data.type_ref {
+        let _ty = ctx.lower_ty(type_ref);
+    }
+    let generics = generics(db.upcast(), def.into());
+    let type_alias_impl_traits = ImplTraits {
+        impl_traits: match ctx.impl_trait_mode {
+            ImplTraitLoweringState::Opaque(x) => x.into_inner(),
+            _ => unreachable!(),
+        },
+    };
+    if type_alias_impl_traits.impl_traits.is_empty() {
+        None
+    } else {
+        Some(Arc::new(make_binders(db, &generics, type_alias_impl_traits)))
+    }
+}
+
 pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mutability {
     match m {
         hir_def::type_ref::Mutability::Shared => Mutability::Not,
@@ -2064,23 +2181,29 @@ pub(crate) fn lower_to_chalk_mutability(m: hir_def::type_ref::Mutability) -> Mut
 /// Returns `Some` of the lowered generic arg. `None` if the provided arg is a lifetime.
 pub(crate) fn generic_arg_to_chalk<'a, T>(
     db: &dyn HirDatabase,
-    kind_id: Either<TypeParamId, ConstParamId>,
+    kind_id: GenericParamId,
     arg: &'a GenericArg,
     this: &mut T,
     for_type: impl FnOnce(&mut T, &TypeRef) -> Ty + 'a,
     for_const: impl FnOnce(&mut T, &ConstRef, Ty) -> Const + 'a,
+    for_lifetime: impl FnOnce(&mut T, &LifetimeRef) -> Lifetime + 'a,
 ) -> Option<crate::GenericArg> {
     let kind = match kind_id {
-        Either::Left(_) => ParamKind::Type,
+        GenericParamId::TypeParamId(_) => ParamKind::Type,
-        Either::Right(id) => {
+        GenericParamId::ConstParamId(id) => {
             let ty = db.const_param_ty(id);
             ParamKind::Const(ty)
         }
+        GenericParamId::LifetimeParamId(_) => ParamKind::Lifetime,
     };
     Some(match (arg, kind) {
         (GenericArg::Type(type_ref), ParamKind::Type) => for_type(this, type_ref).cast(Interner),
         (GenericArg::Const(c), ParamKind::Const(c_ty)) => for_const(this, c, c_ty).cast(Interner),
+        (GenericArg::Lifetime(lifetime_ref), ParamKind::Lifetime) => {
+            for_lifetime(this, lifetime_ref).cast(Interner)
+        }
         (GenericArg::Const(_), ParamKind::Type) => TyKind::Error.intern(Interner).cast(Interner),
+        (GenericArg::Lifetime(_), ParamKind::Type) => TyKind::Error.intern(Interner).cast(Interner),
         (GenericArg::Type(t), ParamKind::Const(c_ty)) => {
             // We want to recover simple idents, which parser detects them
             // as types. Maybe here is not the best place to do it, but
@@ -2096,7 +2219,9 @@ pub(crate) fn generic_arg_to_chalk<'a, T>(
             }
             unknown_const_as_generic(c_ty)
         }
-        (GenericArg::Lifetime(_), _) => return None,
+        (GenericArg::Lifetime(_), ParamKind::Const(c_ty)) => unknown_const_as_generic(c_ty),
+        (GenericArg::Type(_), ParamKind::Lifetime) => error_lifetime().cast(Interner),
+        (GenericArg::Const(_), ParamKind::Lifetime) => error_lifetime().cast(Interner),
     })
 }
 

src/tools/rust-analyzer/crates/hir-ty/src/mapping.rs

@@ -151,6 +151,14 @@ pub fn lt_from_placeholder_idx(db: &dyn HirDatabase, idx: PlaceholderIndex) -> L
     db.lookup_intern_lifetime_param_id(interned_id)
 }
 
+pub fn lt_to_placeholder_idx(db: &dyn HirDatabase, id: LifetimeParamId) -> PlaceholderIndex {
+    let interned_id = db.intern_lifetime_param_id(id);
+    PlaceholderIndex {
+        ui: chalk_ir::UniverseIndex::ROOT,
+        idx: salsa::InternKey::as_intern_id(&interned_id).as_usize(),
+    }
+}
+
 pub fn to_chalk_trait_id(id: TraitId) -> ChalkTraitId {
     chalk_ir::TraitId(salsa::InternKey::as_intern_id(&id))
 }

src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs

@@ -4,7 +4,7 @@
 //! and the corresponding code mostly in rustc_hir_analysis/check/method/probe.rs.
 use std::ops::ControlFlow;
 
-use base_db::{CrateId, Edition};
+use base_db::CrateId;
 use chalk_ir::{cast::Cast, Mutability, TyKind, UniverseIndex, WhereClause};
 use hir_def::{
     data::{adt::StructFlags, ImplData},
@@ -15,6 +15,7 @@ use hir_def::{
 use hir_expand::name::Name;
 use rustc_hash::{FxHashMap, FxHashSet};
 use smallvec::{smallvec, SmallVec};
+use span::Edition;
 use stdx::never;
 use triomphe::Arc;
 
@@ -643,7 +644,7 @@ pub fn is_dyn_method(
     let ItemContainerId::TraitId(trait_id) = func.lookup(db.upcast()).container else {
         return None;
     };
-    let trait_params = db.generic_params(trait_id.into()).type_or_consts.len();
+    let trait_params = db.generic_params(trait_id.into()).len();
     let fn_params = fn_subst.len(Interner) - trait_params;
     let trait_ref = TraitRef {
         trait_id: to_chalk_trait_id(trait_id),
@@ -685,7 +686,7 @@ pub(crate) fn lookup_impl_method_query(
     let ItemContainerId::TraitId(trait_id) = func.lookup(db.upcast()).container else {
         return (func, fn_subst);
     };
-    let trait_params = db.generic_params(trait_id.into()).type_or_consts.len();
+    let trait_params = db.generic_params(trait_id.into()).len();
     let fn_params = fn_subst.len(Interner) - trait_params;
     let trait_ref = TraitRef {
         trait_id: to_chalk_trait_id(trait_id),
@@ -966,7 +967,7 @@ pub fn iterate_method_candidates_dyn(
             // the methods by autoderef order of *receiver types*, not *self
             // types*.
 
-            let mut table = InferenceTable::new(db, env.clone());
+            let mut table = InferenceTable::new(db, env);
             let ty = table.instantiate_canonical(ty.clone());
             let deref_chain = autoderef_method_receiver(&mut table, ty);
 
@@ -1044,7 +1045,7 @@ fn iterate_method_candidates_with_autoref(
     let ref_muted = Canonical {
         value: TyKind::Ref(Mutability::Mut, static_lifetime(), receiver_ty.value.clone())
             .intern(Interner),
-        binders: receiver_ty.binders.clone(),
+        binders: receiver_ty.binders,
     };
 
     iterate_method_candidates_by_receiver(ref_muted, first_adjustment.with_autoref(Mutability::Mut))
@@ -1060,7 +1061,7 @@ fn iterate_method_candidates_by_receiver(
     name: Option<&Name>,
     mut callback: &mut dyn FnMut(ReceiverAdjustments, AssocItemId, bool) -> ControlFlow<()>,
 ) -> ControlFlow<()> {
-    let receiver_ty = table.instantiate_canonical(receiver_ty.clone());
+    let receiver_ty = table.instantiate_canonical(receiver_ty);
     // We're looking for methods with *receiver* type receiver_ty. These could
     // be found in any of the derefs of receiver_ty, so we have to go through
     // that, including raw derefs.
@@ -1456,7 +1457,7 @@ fn is_valid_trait_method_candidate(
                 if let Some(receiver_ty) = receiver_ty {
                     check_that!(data.has_self_param());
 
-                    let fn_subst = TyBuilder::subst_for_def(db, fn_id, Some(impl_subst.clone()))
+                    let fn_subst = TyBuilder::subst_for_def(db, fn_id, Some(impl_subst))
                         .fill_with_inference_vars(table)
                         .build();
 

src/tools/rust-analyzer/crates/hir-ty/src/mir/eval.rs

@@ -1931,7 +1931,11 @@ impl Evaluator<'_> {
             ty: &Ty,
             locals: &Locals,
             mm: &mut ComplexMemoryMap,
+            stack_depth_limit: usize,
         ) -> Result<()> {
+            if stack_depth_limit.checked_sub(1).is_none() {
+                return Err(MirEvalError::StackOverflow);
+            }
             match ty.kind(Interner) {
                 TyKind::Ref(_, _, t) => {
                     let size = this.size_align_of(t, locals)?;
@@ -1970,7 +1974,14 @@ impl Evaluator<'_> {
                             if let Some(ty) = check_inner {
                                 for i in 0..count {
                                     let offset = element_size * i;
-                                    rec(this, &b[offset..offset + element_size], ty, locals, mm)?;
+                                    rec(
+                                        this,
+                                        &b[offset..offset + element_size],
+                                        ty,
+                                        locals,
+                                        mm,
+                                        stack_depth_limit - 1,
+                                    )?;
                                 }
                             }
                         }
@@ -1984,7 +1995,14 @@ impl Evaluator<'_> {
                     let size = this.size_of_sized(inner, locals, "inner of array")?;
                     for i in 0..len {
                         let offset = i * size;
-                        rec(this, &bytes[offset..offset + size], inner, locals, mm)?;
+                        rec(
+                            this,
+                            &bytes[offset..offset + size],
+                            inner,
+                            locals,
+                            mm,
+                            stack_depth_limit - 1,
+                        )?;
                     }
                 }
                 chalk_ir::TyKind::Tuple(_, subst) => {
@@ -1993,7 +2011,14 @@ impl Evaluator<'_> {
                         let ty = ty.assert_ty_ref(Interner); // Tuple only has type argument
                         let offset = layout.fields.offset(id).bytes_usize();
                         let size = this.layout(ty)?.size.bytes_usize();
-                        rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
+                        rec(
+                            this,
+                            &bytes[offset..offset + size],
+                            ty,
+                            locals,
+                            mm,
+                            stack_depth_limit - 1,
+                        )?;
                     }
                 }
                 chalk_ir::TyKind::Adt(adt, subst) => match adt.0 {
@@ -2008,7 +2033,14 @@ impl Evaluator<'_> {
                                 .bytes_usize();
                             let ty = &field_types[f].clone().substitute(Interner, subst);
                             let size = this.layout(ty)?.size.bytes_usize();
-                            rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
+                            rec(
+                                this,
+                                &bytes[offset..offset + size],
+                                ty,
+                                locals,
+                                mm,
+                                stack_depth_limit - 1,
+                            )?;
                         }
                     }
                     AdtId::EnumId(e) => {
@@ -2027,7 +2059,14 @@ impl Evaluator<'_> {
                                     l.fields.offset(u32::from(f.into_raw()) as usize).bytes_usize();
                                 let ty = &field_types[f].clone().substitute(Interner, subst);
                                 let size = this.layout(ty)?.size.bytes_usize();
-                                rec(this, &bytes[offset..offset + size], ty, locals, mm)?;
+                                rec(
+                                    this,
+                                    &bytes[offset..offset + size],
+                                    ty,
+                                    locals,
+                                    mm,
+                                    stack_depth_limit - 1,
+                                )?;
                             }
                         }
                     }
@@ -2038,7 +2077,7 @@ impl Evaluator<'_> {
             Ok(())
         }
         let mut mm = ComplexMemoryMap::default();
-        rec(self, bytes, ty, locals, &mut mm)?;
+        rec(self, bytes, ty, locals, &mut mm, self.stack_depth_limit - 1)?;
         Ok(mm)
     }
 
@@ -2317,7 +2356,7 @@ impl Evaluator<'_> {
 
     fn exec_fn_with_args(
         &mut self,
-        def: FunctionId,
+        mut def: FunctionId,
         args: &[IntervalAndTy],
         generic_args: Substitution,
         locals: &Locals,
@@ -2335,6 +2374,9 @@ impl Evaluator<'_> {
         )? {
             return Ok(None);
         }
+        if let Some(redirect_def) = self.detect_and_redirect_special_function(def)? {
+            def = redirect_def;
+        }
         let arg_bytes = args.iter().map(|it| IntervalOrOwned::Borrowed(it.interval));
         match self.get_mir_or_dyn_index(def, generic_args.clone(), locals, span)? {
             MirOrDynIndex::Dyn(self_ty_idx) => {

src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs

@@ -13,7 +13,7 @@ use crate::mir::eval::{
     name, pad16, static_lifetime, Address, AdtId, Arc, BuiltinType, Evaluator, FunctionId,
     HasModule, HirDisplay, Interned, InternedClosure, Interner, Interval, IntervalAndTy,
     IntervalOrOwned, ItemContainerId, LangItem, Layout, Locals, Lookup, MirEvalError, MirSpan,
-    ModPath, Mutability, Result, Substitution, Ty, TyBuilder, TyExt,
+    Mutability, Result, Substitution, Ty, TyBuilder, TyExt,
 };
 
 mod simd;
@@ -158,6 +158,25 @@ impl Evaluator<'_> {
         Ok(false)
     }
 
+    pub(super) fn detect_and_redirect_special_function(
+        &mut self,
+        def: FunctionId,
+    ) -> Result<Option<FunctionId>> {
+        // `PanicFmt` is redirected to `ConstPanicFmt`
+        if let Some(LangItem::PanicFmt) = self.db.lang_attr(def.into()) {
+            let resolver =
+                self.db.crate_def_map(self.crate_id).crate_root().resolver(self.db.upcast());
+
+            let Some(hir_def::lang_item::LangItemTarget::Function(const_panic_fmt)) =
+                self.db.lang_item(resolver.krate(), LangItem::ConstPanicFmt)
+            else {
+                not_supported!("const_panic_fmt lang item not found or not a function");
+            };
+            return Ok(Some(const_panic_fmt));
+        }
+        Ok(None)
+    }
+
     /// Clone has special impls for tuples and function pointers
     fn exec_clone(
         &mut self,
@@ -291,9 +310,14 @@ impl Evaluator<'_> {
         use LangItem::*;
         let candidate = self.db.lang_attr(def.into())?;
         // We want to execute these functions with special logic
-        if [PanicFmt, BeginPanic, SliceLen, DropInPlace].contains(&candidate) {
+        // `PanicFmt` is not detected here as it's redirected later.
+        if [BeginPanic, SliceLen, DropInPlace].contains(&candidate) {
             return Some(candidate);
         }
+        if self.db.attrs(def.into()).by_key("rustc_const_panic_str").exists() {
+            // `#[rustc_const_panic_str]` is treated like `lang = "begin_panic"` by rustc CTFE.
+            return Some(LangItem::BeginPanic);
+        }
         None
     }
 
@@ -309,43 +333,6 @@ impl Evaluator<'_> {
         let mut args = args.iter();
         match it {
             BeginPanic => Err(MirEvalError::Panic("<unknown-panic-payload>".to_owned())),
-            PanicFmt => {
-                let message = (|| {
-                    let resolver = self
-                        .db
-                        .crate_def_map(self.crate_id)
-                        .crate_root()
-                        .resolver(self.db.upcast());
-                    let Some(format_fn) = resolver.resolve_path_in_value_ns_fully(
-                        self.db.upcast(),
-                        &hir_def::path::Path::from_known_path_with_no_generic(
-                            ModPath::from_segments(
-                                hir_expand::mod_path::PathKind::Abs,
-                                [name![std], name![fmt], name![format]],
-                            ),
-                        ),
-                    ) else {
-                        not_supported!("std::fmt::format not found");
-                    };
-                    let hir_def::resolver::ValueNs::FunctionId(format_fn) = format_fn else {
-                        not_supported!("std::fmt::format is not a function")
-                    };
-                    let interval = self.interpret_mir(
-                        self.db
-                            .mir_body(format_fn.into())
-                            .map_err(|e| MirEvalError::MirLowerError(format_fn, e))?,
-                        args.map(|x| IntervalOrOwned::Owned(x.clone())),
-                    )?;
-                    let message_string = interval.get(self)?;
-                    let addr =
-                        Address::from_bytes(&message_string[self.ptr_size()..2 * self.ptr_size()])?;
-                    let size = from_bytes!(usize, message_string[2 * self.ptr_size()..]);
-                    Ok(std::string::String::from_utf8_lossy(self.read_memory(addr, size)?)
-                        .into_owned())
-                })()
-                .unwrap_or_else(|e| format!("Failed to render panic format args: {e:?}"));
-                Err(MirEvalError::Panic(message))
-            }
             SliceLen => {
                 let arg = args.next().ok_or(MirEvalError::InternalError(
                     "argument of <[T]>::len() is not provided".into(),

src/tools/rust-analyzer/crates/hir-ty/src/mir/monomorphization.rs

@@ -82,6 +82,9 @@ impl FallibleTypeFolder<Interner> for Filler<'_> {
                         };
                         filler.try_fold_ty(infer.type_of_rpit[idx].clone(), outer_binder)
                     }
+                    crate::ImplTraitId::AssociatedTypeImplTrait(..) => {
+                        not_supported!("associated type impl trait");
+                    }
                     crate::ImplTraitId::AsyncBlockTypeImplTrait(_, _) => {
                         not_supported!("async block impl trait");
                     }
@@ -181,8 +184,16 @@ impl Filler<'_> {
                                     self.generics
                                         .as_ref()
                                         .and_then(|it| it.iter().nth(b.index))
-                                        .unwrap()
+                                        .and_then(|(id, _)| match id {
-                                        .0,
+                                            hir_def::GenericParamId::ConstParamId(id) => {
+                                                Some(hir_def::TypeOrConstParamId::from(id))
+                                            }
+                                            hir_def::GenericParamId::TypeParamId(id) => {
+                                                Some(hir_def::TypeOrConstParamId::from(id))
+                                            }
+                                            _ => None,
+                                        })
+                                        .unwrap(),
                                     self.subst.clone(),
                                 )
                             })?

src/tools/rust-analyzer/crates/hir-ty/src/tests.rs

@@ -298,7 +298,7 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
             if let Some(syntax_ptr) = body_source_map.self_param_syntax() {
                 let root = db.parse_or_expand(syntax_ptr.file_id);
                 let node = syntax_ptr.map(|ptr| ptr.to_node(&root).syntax().clone());
-                types.push((node.clone(), ty));
+                types.push((node, ty));
             }
         }
 

src/tools/rust-analyzer/crates/hir-ty/src/tests/display_source_code.rs

@@ -85,7 +85,7 @@ fn render_dyn_for_ty() {
 trait Foo<'a> {}
 
 fn foo(foo: &dyn for<'a> Foo<'a>) {}
-    // ^^^ &dyn Foo
+    // ^^^ &dyn Foo<'static>
 "#,
     );
 }

src/tools/rust-analyzer/crates/hir-ty/src/tests/patterns.rs

@@ -1109,7 +1109,7 @@ fn var_args() {
 #[lang = "va_list"]
 pub struct VaListImpl<'f>;
 fn my_fn(foo: ...) {}
-       //^^^ VaListImpl<'_>
+       //^^^ VaListImpl<'static>
 "#,
     );
 }

src/tools/rust-analyzer/crates/hir-ty/src/tests/regression.rs

@@ -896,13 +896,13 @@ fn flush(&self) {
 "#,
         expect![[r#"
             123..127 'self': &Mutex<T>
-            150..152 '{}': MutexGuard<'_, T>
+            150..152 '{}': MutexGuard<'static, T>
             234..238 'self': &{unknown}
             240..290 '{     ...()); }': ()
             250..251 'w': &Mutex<BufWriter>
             276..287 '*(w.lock())': BufWriter
             278..279 'w': &Mutex<BufWriter>
-            278..286 'w.lock()': MutexGuard<'_, BufWriter>
+            278..286 'w.lock()': MutexGuard<'static, BufWriter>
         "#]],
     );
 }

src/tools/rust-analyzer/crates/hir-ty/src/tests/simple.rs

@@ -3092,7 +3092,7 @@ fn main() {
             389..394 'boxed': Box<Foo<i32>>
             389..406 'boxed....nner()': &i32
             416..421 'good1': &i32
-            424..438 'Foo::get_inner': fn get_inner<i32>(&Box<Foo<i32>>) -> &i32
+            424..438 'Foo::get_inner': fn get_inner<i32, 'static>(&Box<Foo<i32>>) -> &i32
             424..446 'Foo::g...boxed)': &i32
             439..445 '&boxed': &Box<Foo<i32>>
             440..445 'boxed': Box<Foo<i32>>
@@ -3100,7 +3100,7 @@ fn main() {
             464..469 'boxed': Box<Foo<i32>>
             464..480 'boxed....self()': &Foo<i32>
             490..495 'good2': &Foo<i32>
-            498..511 'Foo::get_self': fn get_self<i32>(&Box<Foo<i32>>) -> &Foo<i32>
+            498..511 'Foo::get_self': fn get_self<i32, 'static>(&Box<Foo<i32>>) -> &Foo<i32>
             498..519 'Foo::g...boxed)': &Foo<i32>
             512..518 '&boxed': &Box<Foo<i32>>
             513..518 'boxed': Box<Foo<i32>>
@@ -3659,7 +3659,7 @@ fn main() {
     let are = "are";
     let count = 10;
     builtin#format_args("hello {count:02} {} friends, we {are:?} {0}{last}", "fancy", last = "!");
- // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type: Arguments<'_>
+ // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type: Arguments<'static>
 }
 "#,
     );

src/tools/rust-analyzer/crates/hir-ty/src/tests/traits.rs

@@ -1278,6 +1278,40 @@ fn bar() {
     );
 }
 
+#[test]
+fn argument_assoc_impl_trait() {
+    check_infer(
+        r#"
+trait Outer {
+    type Item;
+}
+
+trait Inner { }
+
+fn foo<T: Outer<Item = impl Inner>>(baz: T) {
+}
+
+impl Outer for usize {
+    type Item = usize;
+}
+
+impl Inner for usize {}
+
+fn main() {
+    foo(2);
+}
+"#,
+        expect![[r#"
+            85..88 'baz': T
+            93..96 '{ }': ()
+            182..197 '{     foo(2); }': ()
+            188..191 'foo': fn foo<usize>(usize)
+            188..194 'foo(2)': ()
+            192..193 '2': usize
+        "#]],
+    );
+}
+
 #[test]
 fn simple_return_pos_impl_trait() {
     cov_mark::check!(lower_rpit);
@@ -4655,3 +4689,78 @@ fn f<T: Send, U>() {
 "#,
     );
 }
+
+#[test]
+fn associated_type_impl_trait() {
+    check_types(
+        r#"
+trait Foo {}
+struct S1;
+impl Foo for S1 {}
+
+trait Bar {
+    type Item;
+    fn bar(&self) -> Self::Item;
+}
+struct S2;
+impl Bar for S2 {
+    type Item = impl Foo;
+    fn bar(&self) -> Self::Item {
+        S1
+    }
+}
+
+fn test() {
+    let x = S2.bar();
+      //^ impl Foo + ?Sized
+}
+        "#,
+    );
+}
+
+#[test]
+fn associated_type_impl_traits_complex() {
+    check_types(
+        r#"
+struct Unary<T>(T);
+struct Binary<T, U>(T, U);
+
+trait Foo {}
+struct S1;
+impl Foo for S1 {}
+
+trait Bar {
+    type Item;
+    fn bar(&self) -> Unary<Self::Item>;
+}
+struct S2;
+impl Bar for S2 {
+    type Item = Unary<impl Foo>;
+    fn bar(&self) -> Unary<<Self as Bar>::Item> {
+        Unary(Unary(S1))
+    }
+}
+
+trait Baz {
+    type Target1;
+    type Target2;
+    fn baz(&self) -> Binary<Self::Target1, Self::Target2>;
+}
+struct S3;
+impl Baz for S3 {
+    type Target1 = impl Foo;
+    type Target2 = Unary<impl Bar>;
+    fn baz(&self) -> Binary<Self::Target1, Self::Target2> {
+        Binary(S1, Unary(S2))
+    }
+}
+
+fn test() {
+    let x = S3.baz();
+      //^ Binary<impl Foo + ?Sized, Unary<impl Bar + ?Sized>>
+    let y = x.1.0.bar();
+      //^ Unary<Bar::Item<impl Bar + ?Sized>>
+}
+        "#,
+    );
+}

src/tools/rust-analyzer/crates/hir-ty/src/utils.rs

@@ -9,18 +9,18 @@ use chalk_ir::{
     fold::{FallibleTypeFolder, Shift},
     BoundVar, DebruijnIndex,
 };
-use either::Either;
 use hir_def::{
     db::DefDatabase,
     generics::{
-        GenericParams, TypeOrConstParamData, TypeParamProvenance, WherePredicate,
+        GenericParamDataRef, GenericParams, LifetimeParamData, TypeOrConstParamData,
-        WherePredicateTypeTarget,
+        TypeParamProvenance, WherePredicate, WherePredicateTypeTarget,
     },
     lang_item::LangItem,
     resolver::{HasResolver, TypeNs},
     type_ref::{TraitBoundModifier, TypeRef},
-    ConstParamId, EnumId, EnumVariantId, FunctionId, GenericDefId, ItemContainerId, Lookup,
+    ConstParamId, EnumId, EnumVariantId, FunctionId, GenericDefId, GenericParamId, ItemContainerId,
-    OpaqueInternableThing, TraitId, TypeAliasId, TypeOrConstParamId, TypeParamId,
+    LifetimeParamId, Lookup, OpaqueInternableThing, TraitId, TypeAliasId, TypeOrConstParamId,
+    TypeParamId,
 };
 use hir_expand::name::Name;
 use intern::Interned;
@@ -270,64 +270,130 @@ pub(crate) struct Generics {
 }
 
 impl Generics {
-    pub(crate) fn iter_id(&self) -> impl Iterator<Item = Either<TypeParamId, ConstParamId>> + '_ {
+    pub(crate) fn iter_id(&self) -> impl Iterator<Item = GenericParamId> + '_ {
-        self.iter().map(|(id, data)| match data {
+        self.iter().map(|(id, _)| id)
-            TypeOrConstParamData::TypeParamData(_) => Either::Left(TypeParamId::from_unchecked(id)),
-            TypeOrConstParamData::ConstParamData(_) => {
-                Either::Right(ConstParamId::from_unchecked(id))
-            }
-        })
     }
 
     /// Iterator over types and const params of self, then parent.
     pub(crate) fn iter<'a>(
         &'a self,
-    ) -> impl DoubleEndedIterator<Item = (TypeOrConstParamId, &'a TypeOrConstParamData)> + 'a {
+    ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'a>)> + 'a {
-        let to_toc_id = |it: &'a Generics| {
+        let from_toc_id = |it: &'a Generics| {
-            move |(local_id, p)| (TypeOrConstParamId { parent: it.def, local_id }, p)
+            move |(local_id, p): (_, &'a TypeOrConstParamData)| {
+                let id = TypeOrConstParamId { parent: it.def, local_id };
+                match p {
+                    TypeOrConstParamData::TypeParamData(p) => (
+                        GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)),
+                        GenericParamDataRef::TypeParamData(p),
+                    ),
+                    TypeOrConstParamData::ConstParamData(p) => (
+                        GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)),
+                        GenericParamDataRef::ConstParamData(p),
+                    ),
+                }
+            }
         };
-        self.params.iter().map(to_toc_id(self)).chain(self.iter_parent())
+
+        let from_lt_id = |it: &'a Generics| {
+            move |(local_id, p): (_, &'a LifetimeParamData)| {
+                (
+                    GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }),
+                    GenericParamDataRef::LifetimeParamData(p),
+                )
+            }
+        };
+
+        let lt_iter = self.params.iter_lt().map(from_lt_id(self));
+        self.params.iter().map(from_toc_id(self)).chain(lt_iter).chain(self.iter_parent())
     }
 
     /// Iterate over types and const params without parent params.
     pub(crate) fn iter_self<'a>(
         &'a self,
-    ) -> impl DoubleEndedIterator<Item = (TypeOrConstParamId, &'a TypeOrConstParamData)> + 'a {
+    ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'a>)> + 'a {
-        let to_toc_id = |it: &'a Generics| {
+        let from_toc_id = |it: &'a Generics| {
-            move |(local_id, p)| (TypeOrConstParamId { parent: it.def, local_id }, p)
+            move |(local_id, p): (_, &'a TypeOrConstParamData)| {
+                let id = TypeOrConstParamId { parent: it.def, local_id };
+                match p {
+                    TypeOrConstParamData::TypeParamData(p) => (
+                        GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)),
+                        GenericParamDataRef::TypeParamData(p),
+                    ),
+                    TypeOrConstParamData::ConstParamData(p) => (
+                        GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)),
+                        GenericParamDataRef::ConstParamData(p),
+                    ),
+                }
+            }
         };
-        self.params.iter().map(to_toc_id(self))
+
+        let from_lt_id = |it: &'a Generics| {
+            move |(local_id, p): (_, &'a LifetimeParamData)| {
+                (
+                    GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }),
+                    GenericParamDataRef::LifetimeParamData(p),
+                )
+            }
+        };
+
+        self.params.iter().map(from_toc_id(self)).chain(self.params.iter_lt().map(from_lt_id(self)))
     }
 
     /// Iterator over types and const params of parent.
-    pub(crate) fn iter_parent(
+    #[allow(clippy::needless_lifetimes)]
-        &self,
+    pub(crate) fn iter_parent<'a>(
-    ) -> impl DoubleEndedIterator<Item = (TypeOrConstParamId, &TypeOrConstParamData)> {
+        &'a self,
+    ) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'a>)> + 'a {
         self.parent_generics().into_iter().flat_map(|it| {
-            let to_toc_id =
+            let from_toc_id = move |(local_id, p): (_, &'a TypeOrConstParamData)| {
-                move |(local_id, p)| (TypeOrConstParamId { parent: it.def, local_id }, p);
+                let id = TypeOrConstParamId { parent: it.def, local_id };
-            it.params.iter().map(to_toc_id)
+                match p {
+                    TypeOrConstParamData::TypeParamData(p) => (
+                        GenericParamId::TypeParamId(TypeParamId::from_unchecked(id)),
+                        GenericParamDataRef::TypeParamData(p),
+                    ),
+                    TypeOrConstParamData::ConstParamData(p) => (
+                        GenericParamId::ConstParamId(ConstParamId::from_unchecked(id)),
+                        GenericParamDataRef::ConstParamData(p),
+                    ),
+                }
+            };
+
+            let from_lt_id = move |(local_id, p): (_, &'a LifetimeParamData)| {
+                (
+                    GenericParamId::LifetimeParamId(LifetimeParamId { parent: it.def, local_id }),
+                    GenericParamDataRef::LifetimeParamData(p),
+                )
+            };
+            let lt_iter = it.params.iter_lt().map(from_lt_id);
+            it.params.iter().map(from_toc_id).chain(lt_iter)
         })
     }
 
     /// Returns total number of generic parameters in scope, including those from parent.
     pub(crate) fn len(&self) -> usize {
         let parent = self.parent_generics().map_or(0, Generics::len);
-        let child = self.params.type_or_consts.len();
+        let child = self.params.len();
         parent + child
     }
 
-    /// Returns numbers of generic parameters excluding those from parent.
+    /// Returns numbers of generic parameters and lifetimes excluding those from parent.
     pub(crate) fn len_self(&self) -> usize {
+        self.params.len()
+    }
+
+    /// Returns number of generic parameter excluding those from parent
+    fn len_params(&self) -> usize {
         self.params.type_or_consts.len()
     }
 
-    /// (parent total, self param, type param list, const param list, impl trait)
+    /// (parent total, self param, type params, const params, impl trait list, lifetimes)
-    pub(crate) fn provenance_split(&self) -> (usize, usize, usize, usize, usize) {
+    pub(crate) fn provenance_split(&self) -> (usize, usize, usize, usize, usize, usize) {
         let mut self_params = 0;
         let mut type_params = 0;
         let mut impl_trait_params = 0;
         let mut const_params = 0;
+        let mut lifetime_params = 0;
         self.params.iter().for_each(|(_, data)| match data {
             TypeOrConstParamData::TypeParamData(p) => match p.provenance {
                 TypeParamProvenance::TypeParamList => type_params += 1,
@@ -337,8 +403,10 @@ impl Generics {
             TypeOrConstParamData::ConstParamData(_) => const_params += 1,
         });
 
+        self.params.iter_lt().for_each(|(_, _)| lifetime_params += 1);
+
         let parent_len = self.parent_generics().map_or(0, Generics::len);
-        (parent_len, self_params, type_params, const_params, impl_trait_params)
+        (parent_len, self_params, type_params, const_params, impl_trait_params, lifetime_params)
     }
 
     pub(crate) fn param_idx(&self, param: TypeOrConstParamId) -> Option<usize> {
@@ -358,6 +426,26 @@ impl Generics {
         }
     }
 
+    pub(crate) fn lifetime_idx(&self, lifetime: LifetimeParamId) -> Option<usize> {
+        Some(self.find_lifetime(lifetime)?.0)
+    }
+
+    fn find_lifetime(&self, lifetime: LifetimeParamId) -> Option<(usize, &LifetimeParamData)> {
+        if lifetime.parent == self.def {
+            let (idx, (_local_id, data)) = self
+                .params
+                .iter_lt()
+                .enumerate()
+                .find(|(_, (idx, _))| *idx == lifetime.local_id)?;
+
+            Some((self.len_params() + idx, data))
+        } else {
+            self.parent_generics()
+                .and_then(|g| g.find_lifetime(lifetime))
+                .map(|(idx, data)| (self.len_self() + idx, data))
+        }
+    }
+
     pub(crate) fn parent_generics(&self) -> Option<&Generics> {
         self.parent_generics.as_deref()
     }
@@ -371,10 +459,15 @@ impl Generics {
         Substitution::from_iter(
             Interner,
             self.iter_id().enumerate().map(|(idx, id)| match id {
-                Either::Left(_) => BoundVar::new(debruijn, idx).to_ty(Interner).cast(Interner),
+                GenericParamId::ConstParamId(id) => BoundVar::new(debruijn, idx)
-                Either::Right(id) => BoundVar::new(debruijn, idx)
                     .to_const(Interner, db.const_param_ty(id))
                     .cast(Interner),
+                GenericParamId::TypeParamId(_) => {
+                    BoundVar::new(debruijn, idx).to_ty(Interner).cast(Interner)
+                }
+                GenericParamId::LifetimeParamId(_) => {
+                    BoundVar::new(debruijn, idx).to_lifetime(Interner).cast(Interner)
+                }
             }),
         )
     }
@@ -384,12 +477,15 @@ impl Generics {
         Substitution::from_iter(
             Interner,
             self.iter_id().map(|id| match id {
-                Either::Left(id) => {
+                GenericParamId::TypeParamId(id) => {
                     crate::to_placeholder_idx(db, id.into()).to_ty(Interner).cast(Interner)
                 }
-                Either::Right(id) => crate::to_placeholder_idx(db, id.into())
+                GenericParamId::ConstParamId(id) => crate::to_placeholder_idx(db, id.into())
                     .to_const(Interner, db.const_param_ty(id))
                     .cast(Interner),
+                GenericParamId::LifetimeParamId(id) => {
+                    crate::lt_to_placeholder_idx(db, id).to_lifetime(Interner).cast(Interner)
+                }
             }),
         )
     }

src/tools/rust-analyzer/crates/hir/src/display.rs

@@ -186,18 +186,29 @@ impl HirDisplay for Struct {
             }
             StructKind::Record => {
                 let has_where_clause = write_where_clause(def_id, f)?;
-                let fields = self.fields(f.db);
+                if let Some(limit) = f.entity_limit {
-                f.write_char(if !has_where_clause { ' ' } else { '\n' })?;
+                    let fields = self.fields(f.db);
-                if fields.is_empty() {
+                    let count = fields.len().min(limit);
-                    f.write_str("{}")?;
+                    f.write_char(if !has_where_clause { ' ' } else { '\n' })?;
-                } else {
+                    if count == 0 {
-                    f.write_str("{\n")?;
+                        if fields.is_empty() {
-                    for field in self.fields(f.db) {
+                            f.write_str("{}")?;
-                        f.write_str("    ")?;
+                        } else {
-                        field.hir_fmt(f)?;
+                            f.write_str("{ /* … */ }")?;
-                        f.write_str(",\n")?;
+                        }
+                    } else {
+                        f.write_str(" {\n")?;
+                        for field in &fields[..count] {
+                            f.write_str("    ")?;
+                            field.hir_fmt(f)?;
+                            f.write_str(",\n")?;
+                        }
+
+                        if fields.len() > count {
+                            f.write_str("    /* … */\n")?;
+                        }
+                        f.write_str("}")?;
                     }
-                    f.write_str("}")?;
                 }
             }
             StructKind::Unit => _ = write_where_clause(def_id, f)?,

src/tools/rust-analyzer/crates/hir/src/lib.rs

@@ -38,7 +38,7 @@ mod display;
 use std::{iter, mem::discriminant, ops::ControlFlow};
 
 use arrayvec::ArrayVec;
-use base_db::{CrateDisplayName, CrateId, CrateOrigin, Edition, FileId};
+use base_db::{CrateDisplayName, CrateId, CrateOrigin, FileId};
 use either::Either;
 use hir_def::{
     body::{BodyDiagnostic, SyntheticSyntax},
@@ -65,7 +65,7 @@ use hir_ty::{
     consteval::{try_const_usize, unknown_const_as_generic, ConstExt},
     db::InternedClosure,
     diagnostics::BodyValidationDiagnostic,
-    known_const_to_ast,
+    error_lifetime, known_const_to_ast,
     layout::{Layout as TyLayout, RustcEnumVariantIdx, RustcFieldIdx, TagEncoding},
     method_resolution::{self, TyFingerprint},
     mir::{interpret_mir, MutBorrowKind},
@@ -79,6 +79,7 @@ use hir_ty::{
 use itertools::Itertools;
 use nameres::diagnostics::DefDiagnosticKind;
 use rustc_hash::FxHashSet;
+use span::Edition;
 use stdx::{impl_from, never};
 use syntax::{
     ast::{self, HasAttrs as _, HasName},
@@ -971,7 +972,7 @@ fn precise_macro_call_location(
                 MacroKind::ProcMacro,
             )
         }
-        MacroCallKind::Derive { ast_id, derive_attr_index, derive_index } => {
+        MacroCallKind::Derive { ast_id, derive_attr_index, derive_index, .. } => {
             let node = ast_id.to_node(db.upcast());
             // Compute the precise location of the macro name's token in the derive
             // list.
@@ -1099,13 +1100,14 @@ impl Field {
             VariantDef::Union(it) => it.id.into(),
             VariantDef::Variant(it) => it.parent_enum(db).id.into(),
         };
-        let mut generics = generics.map(|it| it.ty.clone());
+        let mut generics = generics.map(|it| it.ty);
         let substs = TyBuilder::subst_for_def(db, def_id, None)
             .fill(|x| match x {
                 ParamKind::Type => {
                     generics.next().unwrap_or_else(|| TyKind::Error.intern(Interner)).cast(Interner)
                 }
                 ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+                ParamKind::Lifetime => error_lifetime().cast(Interner),
             })
             .build();
         let ty = db.field_types(var_id)[self.id].clone().substitute(Interner, &substs);
@@ -1416,7 +1418,7 @@ impl Adt {
     }
 
     pub fn layout(self, db: &dyn HirDatabase) -> Result<Layout, LayoutError> {
-        if db.generic_params(self.into()).iter().count() != 0 {
+        if !db.generic_params(self.into()).is_empty() {
             return Err(LayoutError::HasPlaceholder);
         }
         let krate = self.krate(db).id;
@@ -1440,13 +1442,14 @@ impl Adt {
     /// the greatest API, FIXME find a better one.
     pub fn ty_with_args(self, db: &dyn HirDatabase, args: impl Iterator<Item = Type>) -> Type {
         let id = AdtId::from(self);
-        let mut it = args.map(|t| t.ty.clone());
+        let mut it = args.map(|t| t.ty);
         let ty = TyBuilder::def_ty(db, id.into(), None)
             .fill(|x| {
                 let r = it.next().unwrap_or_else(|| TyKind::Error.intern(Interner));
                 match x {
                     ParamKind::Type => r.cast(Interner),
                     ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+                    ParamKind::Lifetime => error_lifetime().cast(Interner),
                 }
             })
             .build();
@@ -1859,12 +1862,13 @@ impl Function {
             ItemContainerId::TraitId(it) => Some(it.into()),
             ItemContainerId::ModuleId(_) | ItemContainerId::ExternBlockId(_) => None,
         };
-        let mut generics = generics.map(|it| it.ty.clone());
+        let mut generics = generics.map(|it| it.ty);
         let mut filler = |x: &_| match x {
             ParamKind::Type => {
                 generics.next().unwrap_or_else(|| TyKind::Error.intern(Interner)).cast(Interner)
             }
             ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+            ParamKind::Lifetime => error_lifetime().cast(Interner),
         };
 
         let parent_substs =
@@ -1954,7 +1958,7 @@ impl Function {
             ItemContainerId::TraitId(it) => Some(it.into()),
             ItemContainerId::ModuleId(_) | ItemContainerId::ExternBlockId(_) => None,
         };
-        let mut generics = generics.map(|it| it.ty.clone());
+        let mut generics = generics.map(|it| it.ty);
         let parent_substs = parent_id.map(|id| {
             TyBuilder::subst_for_def(db, id, None)
                 .fill(|x| match x {
@@ -1963,6 +1967,7 @@ impl Function {
                         .unwrap_or_else(|| TyKind::Error.intern(Interner))
                         .cast(Interner),
                     ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+                    ParamKind::Lifetime => error_lifetime().cast(Interner),
                 })
                 .build()
         });
@@ -2007,8 +2012,7 @@ impl Function {
         }
         let data = db.function_data(self.id);
 
-        data.name.to_smol_str() == "main"
+        data.name.to_smol_str() == "main" || data.attrs.export_name() == Some("main")
-            || data.attrs.export_name().map(core::ops::Deref::deref) == Some("main")
     }
 
     /// Does this function have the ignore attribute?
@@ -2215,12 +2219,13 @@ impl SelfParam {
             }
         };
 
-        let mut generics = generics.map(|it| it.ty.clone());
+        let mut generics = generics.map(|it| it.ty);
         let mut filler = |x: &_| match x {
             ParamKind::Type => {
                 generics.next().unwrap_or_else(|| TyKind::Error.intern(Interner)).cast(Interner)
             }
             ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+            ParamKind::Lifetime => error_lifetime().cast(Interner),
         };
 
         let parent_substs = TyBuilder::subst_for_def(db, parent_id, None).fill(&mut filler).build();
@@ -2592,7 +2597,7 @@ impl Macro {
             },
             MacroId::ProcMacroId(it) => match it.lookup(db.upcast()).kind {
                 ProcMacroKind::CustomDerive => MacroKind::Derive,
-                ProcMacroKind::FuncLike => MacroKind::ProcMacro,
+                ProcMacroKind::Bang => MacroKind::ProcMacro,
                 ProcMacroKind::Attr => MacroKind::Attr,
             },
         }
@@ -3628,16 +3633,41 @@ impl Impl {
                     .filter(filter),
             );
         }
+
+        if let Some(block) =
+            ty.adt_id(Interner).and_then(|def| def.0.module(db.upcast()).containing_block())
+        {
+            if let Some(inherent_impls) = db.inherent_impls_in_block(block) {
+                all.extend(
+                    inherent_impls.for_self_ty(&ty).iter().cloned().map(Self::from).filter(filter),
+                );
+            }
+            if let Some(trait_impls) = db.trait_impls_in_block(block) {
+                all.extend(
+                    trait_impls
+                        .for_self_ty_without_blanket_impls(fp)
+                        .map(Self::from)
+                        .filter(filter),
+                );
+            }
+        }
+
         all
     }
 
     pub fn all_for_trait(db: &dyn HirDatabase, trait_: Trait) -> Vec<Impl> {
-        let krate = trait_.module(db).krate();
+        let module = trait_.module(db);
+        let krate = module.krate();
         let mut all = Vec::new();
         for Crate { id } in krate.transitive_reverse_dependencies(db) {
             let impls = db.trait_impls_in_crate(id);
             all.extend(impls.for_trait(trait_.id).map(Self::from))
         }
+        if let Some(block) = module.id.containing_block() {
+            if let Some(trait_impls) = db.trait_impls_in_block(block) {
+                all.extend(trait_impls.for_trait(trait_.id).map(Self::from));
+            }
+        }
         all
     }
 
@@ -3683,7 +3713,7 @@ impl Impl {
         let macro_file = src.file_id.macro_file()?;
         let loc = macro_file.macro_call_id.lookup(db.upcast());
         let (derive_attr, derive_index) = match loc.kind {
-            MacroCallKind::Derive { ast_id, derive_attr_index, derive_index } => {
+            MacroCallKind::Derive { ast_id, derive_attr_index, derive_index, .. } => {
                 let module_id = self.id.lookup(db.upcast()).container;
                 (
                     db.crate_def_map(module_id.krate())[module_id.local_id]
@@ -4114,6 +4144,7 @@ impl Type {
                         // FIXME: this code is not covered in tests.
                         unknown_const_as_generic(ty.clone())
                     }
+                    ParamKind::Lifetime => error_lifetime().cast(Interner),
                 }
             })
             .build();
@@ -4144,6 +4175,7 @@ impl Type {
                 match it {
                     ParamKind::Type => args.next().unwrap().ty.clone().cast(Interner),
                     ParamKind::Const(ty) => unknown_const_as_generic(ty.clone()),
+                    ParamKind::Lifetime => error_lifetime().cast(Interner),
                 }
             })
             .build();

src/tools/rust-analyzer/crates/hir/src/term_search/tactics.rs

@@ -177,7 +177,7 @@ pub(super) fn type_constructor<'a, DB: HirDatabase>(
                 // Note that we need special case for 0 param constructors because of multi cartesian
                 // product
                 let variant_exprs: Vec<Expr> = if param_exprs.is_empty() {
-                    vec![Expr::Variant { variant, generics: generics.clone(), params: Vec::new() }]
+                    vec![Expr::Variant { variant, generics, params: Vec::new() }]
                 } else {
                     param_exprs
                         .into_iter()
@@ -462,7 +462,7 @@ pub(super) fn free_function<'a, DB: HirDatabase>(
 
 /// # Impl method tactic
 ///
-/// Attempts to to call methods on types from lookup table.
+/// Attempts to call methods on types from lookup table.
 /// This includes both functions from direct impl blocks as well as functions from traits.
 /// Methods defined in impl blocks that are generic and methods that are themselves have
 /// generics are ignored for performance reasons.

src/tools/rust-analyzer/crates/ide-assists/src/handlers/extract_function.rs

@@ -5617,7 +5617,7 @@ fn func<T: Debug>(i: Struct<'_, T>) {
     fun_name(i);
 }
 
-fn $0fun_name(i: Struct<'_, T>) {
+fn $0fun_name(i: Struct<'static, T>) {
     foo(i);
 }
 "#,

src/tools/rust-analyzer/crates/ide-assists/src/handlers/generate_delegate_methods.rs

@@ -614,7 +614,7 @@ struct Foo<'a, T> {
 }
 
 impl<'a, T> Foo<'a, T> {
-    $0fn bar(self, mut b: Vec<&'a Bar<'_, T>>) -> &'a Bar<'_, T> {
+    $0fn bar(self, mut b: Vec<&'a Bar<'a, T>>) -> &'a Bar<'a, T> {
         self.field.bar(b)
     }
 }

src/tools/rust-analyzer/crates/ide-completion/src/completions/dot.rs

@@ -961,11 +961,11 @@ struct Foo { field: i32 }
 impl Foo { fn foo(&self) { $0 } }"#,
             expect![[r#"
                 fd self.field i32
+                me self.foo() fn(&self)
                 lc self       &Foo
                 sp Self       Foo
                 st Foo        Foo
                 bt u32        u32
-                me self.foo() fn(&self)
             "#]],
         );
         check(
@@ -975,11 +975,11 @@ struct Foo(i32);
 impl Foo { fn foo(&mut self) { $0 } }"#,
             expect![[r#"
                 fd self.0     i32
+                me self.foo() fn(&mut self)
                 lc self       &mut Foo
                 sp Self       Foo
                 st Foo        Foo
                 bt u32        u32
-                me self.foo() fn(&mut self)
             "#]],
         );
     }

src/tools/rust-analyzer/crates/ide-completion/src/completions/item_list/trait_impl.rs

@@ -186,11 +186,11 @@ fn add_function_impl(
         if func.assoc_fn_params(ctx.db).is_empty() { "" } else { ".." }
     );
 
-    let completion_kind = if func.has_self_param(ctx.db) {
+    let completion_kind = CompletionItemKind::SymbolKind(if func.has_self_param(ctx.db) {
-        CompletionItemKind::Method
+        SymbolKind::Method
     } else {
-        CompletionItemKind::SymbolKind(SymbolKind::Function)
+        SymbolKind::Function
-    };
+    });
 
     let mut item = CompletionItem::new(completion_kind, replacement_range, label);
     item.lookup_by(format!("fn {}", fn_name.display(ctx.db)))

src/tools/rust-analyzer/crates/ide-completion/src/completions/keyword.rs

@@ -75,8 +75,8 @@ impl Future for A {}
 fn foo(a: A) { a.$0 }
 "#,
             expect![[r#"
-                kw await                  expr.await
                 me into_future() (as IntoFuture) fn(self) -> <Self as IntoFuture>::IntoFuture
+                kw await                  expr.await
                 sn box                    Box::new(expr)
                 sn call                   function(expr)
                 sn dbg                    dbg!(expr)
@@ -102,8 +102,8 @@ fn foo() {
 }
 "#,
             expect![[r#"
-                kw await                  expr.await
                 me into_future() (use core::future::IntoFuture) fn(self) -> <Self as IntoFuture>::IntoFuture
+                kw await                  expr.await
                 sn box                    Box::new(expr)
                 sn call                   function(expr)
                 sn dbg                    dbg!(expr)
@@ -131,8 +131,8 @@ impl IntoFuture for A {}
 fn foo(a: A) { a.$0 }
 "#,
             expect![[r#"
-                kw await                  expr.await
                 me into_future() (as IntoFuture) fn(self) -> <Self as IntoFuture>::IntoFuture
+                kw await                  expr.await
                 sn box                    Box::new(expr)
                 sn call                   function(expr)
                 sn dbg                    dbg!(expr)

src/tools/rust-analyzer/crates/ide-completion/src/context.rs

@@ -540,7 +540,7 @@ impl CompletionContext<'_> {
     /// Whether the given trait is an operator trait or not.
     pub(crate) fn is_ops_trait(&self, trait_: hir::Trait) -> bool {
         match trait_.attrs(self.db).lang() {
-            Some(lang) => OP_TRAIT_LANG_NAMES.contains(&lang.as_str()),
+            Some(lang) => OP_TRAIT_LANG_NAMES.contains(&lang),
             None => false,
         }
     }

src/tools/rust-analyzer/crates/ide-completion/src/item.rs

@@ -342,7 +342,6 @@ pub enum CompletionItemKind {
     BuiltinType,
     InferredType,
     Keyword,
-    Method,
     Snippet,
     UnresolvedReference,
     Expression,
@@ -369,6 +368,7 @@ impl CompletionItemKind {
                 SymbolKind::LifetimeParam => "lt",
                 SymbolKind::Local => "lc",
                 SymbolKind::Macro => "ma",
+                SymbolKind::Method => "me",
                 SymbolKind::ProcMacro => "pm",
                 SymbolKind::Module => "md",
                 SymbolKind::SelfParam => "sp",
@@ -388,7 +388,6 @@ impl CompletionItemKind {
             CompletionItemKind::BuiltinType => "bt",
             CompletionItemKind::InferredType => "it",
             CompletionItemKind::Keyword => "kw",
-            CompletionItemKind::Method => "me",
             CompletionItemKind::Snippet => "sn",
             CompletionItemKind::UnresolvedReference => "??",
             CompletionItemKind::Expression => "ex",

src/tools/rust-analyzer/crates/ide-completion/src/render.rs

@@ -312,7 +312,7 @@ pub(crate) fn render_expr(
         None => ctx.source_range(),
     };
 
-    let mut item = CompletionItem::new(CompletionItemKind::Expression, source_range, label.clone());
+    let mut item = CompletionItem::new(CompletionItemKind::Expression, source_range, label);
 
     let snippet = format!(
         "{}$0",
@@ -677,10 +677,11 @@ mod tests {
 
     #[track_caller]
     fn check_function_relevance(ra_fixture: &str, expect: Expect) {
-        let actual: Vec<_> = do_completion(ra_fixture, CompletionItemKind::Method)
+        let actual: Vec<_> =
-            .into_iter()
+            do_completion(ra_fixture, CompletionItemKind::SymbolKind(SymbolKind::Method))
-            .map(|item| (item.detail.unwrap_or_default(), item.relevance.function))
+                .into_iter()
-            .collect();
+                .map(|item| (item.detail.unwrap_or_default(), item.relevance.function))
+                .collect();
 
         expect.assert_debug_eq(&actual);
     }
@@ -1392,7 +1393,10 @@ impl S {
     /// Method docs
     fn bar(self) { self.$0 }
 }"#,
-            &[CompletionItemKind::Method, CompletionItemKind::SymbolKind(SymbolKind::Field)],
+            &[
+                CompletionItemKind::SymbolKind(SymbolKind::Method),
+                CompletionItemKind::SymbolKind(SymbolKind::Field),
+            ],
             expect![[r#"
                 [
                     CompletionItem {
@@ -1400,7 +1404,9 @@ impl S {
                         source_range: 94..94,
                         delete: 94..94,
                         insert: "bar()$0",
-                        kind: Method,
+                        kind: SymbolKind(
+                            Method,
+                        ),
                         lookup: "bar",
                         detail: "fn(self)",
                         documentation: Documentation(
@@ -1520,7 +1526,7 @@ impl S {
 }
 fn foo(s: S) { s.$0 }
 "#,
-            CompletionItemKind::Method,
+            CompletionItemKind::SymbolKind(SymbolKind::Method),
             expect![[r#"
                 [
                     CompletionItem {
@@ -1528,7 +1534,9 @@ fn foo(s: S) { s.$0 }
                         source_range: 81..81,
                         delete: 81..81,
                         insert: "the_method()$0",
-                        kind: Method,
+                        kind: SymbolKind(
+                            Method,
+                        ),
                         lookup: "the_method",
                         detail: "fn(&self)",
                         relevance: CompletionRelevance {
@@ -2408,7 +2416,10 @@ impl Foo { fn baz(&self) -> u32 { 0 } }
 
 fn foo(f: Foo) { let _: &u32 = f.b$0 }
 "#,
-            &[CompletionItemKind::Method, CompletionItemKind::SymbolKind(SymbolKind::Field)],
+            &[
+                CompletionItemKind::SymbolKind(SymbolKind::Method),
+                CompletionItemKind::SymbolKind(SymbolKind::Field),
+            ],
             expect![[r#"
                 [
                     CompletionItem {
@@ -2416,7 +2427,9 @@ fn foo(f: Foo) { let _: &u32 = f.b$0 }
                         source_range: 109..110,
                         delete: 109..110,
                         insert: "baz()$0",
-                        kind: Method,
+                        kind: SymbolKind(
+                            Method,
+                        ),
                         lookup: "baz",
                         detail: "fn(&self) -> u32",
                         relevance: CompletionRelevance {
@@ -2631,7 +2644,7 @@ fn main() {
     let _: bool = (9 > 2).not$0;
 }
     "#,
-            &[CompletionItemKind::Snippet, CompletionItemKind::Method],
+            &[CompletionItemKind::Snippet, CompletionItemKind::SymbolKind(SymbolKind::Method)],
             expect![[r#"
                 sn not [snippet]
                 me not() (use ops::Not) [type_could_unify+requires_import]
@@ -2664,7 +2677,7 @@ fn main() {
     S.$0
 }
     "#,
-            &[CompletionItemKind::Snippet, CompletionItemKind::Method],
+            &[CompletionItemKind::Snippet, CompletionItemKind::SymbolKind(SymbolKind::Method)],
             expect![[r#"
                 me f() []
                 sn ref []
@@ -2907,7 +2920,7 @@ fn main() {
 }
 "#,
             &[
-                CompletionItemKind::Method,
+                CompletionItemKind::SymbolKind(SymbolKind::Method),
                 CompletionItemKind::SymbolKind(SymbolKind::Field),
                 CompletionItemKind::SymbolKind(SymbolKind::Function),
             ],
@@ -2918,7 +2931,9 @@ fn main() {
                         source_range: 193..193,
                         delete: 193..193,
                         insert: "flush()$0",
-                        kind: Method,
+                        kind: SymbolKind(
+                            Method,
+                        ),
                         lookup: "flush",
                         detail: "fn(&self)",
                         relevance: CompletionRelevance {
@@ -2941,7 +2956,9 @@ fn main() {
                         source_range: 193..193,
                         delete: 193..193,
                         insert: "write()$0",
-                        kind: Method,
+                        kind: SymbolKind(
+                            Method,
+                        ),
                         lookup: "write",
                         detail: "fn(&self)",
                         relevance: CompletionRelevance {

src/tools/rust-analyzer/crates/ide-completion/src/render/function.rs

@@ -68,11 +68,11 @@ fn render(
     };
     let has_self_param = func.self_param(db).is_some();
     let mut item = CompletionItem::new(
-        if has_self_param {
+        CompletionItemKind::SymbolKind(if has_self_param {
-            CompletionItemKind::Method
+            SymbolKind::Method
         } else {
-            CompletionItemKind::SymbolKind(SymbolKind::Function)
+            SymbolKind::Function
-        },
+        }),
         ctx.source_range(),
         call.clone(),
     );

src/tools/rust-analyzer/crates/ide-completion/src/tests/expression.rs

@@ -127,6 +127,7 @@ impl Unit {
             en Enum         Enum
             fn function()   fn()
             fn local_func() fn()
+            me self.foo()   fn(self)
             lc self         Unit
             ma makro!(…)    macro_rules! makro
             md module
@@ -166,7 +167,6 @@ impl Unit {
             kw use
             kw while
             kw while let
-            me self.foo()   fn(self)
             sn macro_rules
             sn pd
             sn ppd

src/tools/rust-analyzer/crates/ide-completion/src/tests/predicate.rs

@@ -19,7 +19,7 @@ struct Foo<'lt, T, const C: usize> where $0 {}
             en Enum      Enum
             ma makro!(…) macro_rules! makro
             md module
-            st Foo<…>    Foo<'_, {unknown}, _>
+            st Foo<…>    Foo<'static, {unknown}, _>
             st Record    Record
             st Tuple     Tuple
             st Unit      Unit
@@ -92,7 +92,7 @@ struct Foo<'lt, T, const C: usize> where for<'a> $0 {}
             en Enum      Enum
             ma makro!(…) macro_rules! makro
             md module
-            st Foo<…>    Foo<'_, {unknown}, _>
+            st Foo<…>    Foo<'static, {unknown}, _>
             st Record    Record
             st Tuple     Tuple
             st Unit      Unit

src/tools/rust-analyzer/crates/ide-completion/src/tests/special.rs

@@ -1,6 +1,7 @@
 //! Tests that don't fit into a specific category.
 
 use expect_test::{expect, Expect};
+use ide_db::SymbolKind;
 
 use crate::{
     tests::{
@@ -316,15 +317,15 @@ trait Sub: Super {
 fn foo<T: Sub>() { T::$0 }
 "#,
         expect![[r#"
-                ct C2 (as Sub)           const C2: ()
+            ct C2 (as Sub)           const C2: ()
-                ct CONST (as Super)      const CONST: u8
+            ct CONST (as Super)      const CONST: u8
-                fn func() (as Super)     fn()
+            fn func() (as Super)     fn()
-                fn subfunc() (as Sub)    fn()
+            fn subfunc() (as Sub)    fn()
-                ta SubTy (as Sub)        type SubTy
+            me method(…) (as Super)  fn(&self)
-                ta Ty (as Super)         type Ty
+            me submethod(…) (as Sub) fn(&self)
-                me method(…) (as Super)  fn(&self)
+            ta SubTy (as Sub)        type SubTy
-                me submethod(…) (as Sub) fn(&self)
+            ta Ty (as Super)         type Ty
-            "#]],
+        "#]],
     );
 }
 
@@ -356,15 +357,15 @@ impl<T> Sub for Wrap<T> {
 }
 "#,
         expect![[r#"
-                ct C2 (as Sub)           const C2: ()
+            ct C2 (as Sub)           const C2: ()
-                ct CONST (as Super)      const CONST: u8
+            ct CONST (as Super)      const CONST: u8
-                fn func() (as Super)     fn()
+            fn func() (as Super)     fn()
-                fn subfunc() (as Sub)    fn()
+            fn subfunc() (as Sub)    fn()
-                ta SubTy (as Sub)        type SubTy
+            me method(…) (as Super)  fn(&self)
-                ta Ty (as Super)         type Ty
+            me submethod(…) (as Sub) fn(&self)
-                me method(…) (as Super)  fn(&self)
+            ta SubTy (as Sub)        type SubTy
-                me submethod(…) (as Sub) fn(&self)
+            ta Ty (as Super)         type Ty
-            "#]],
+        "#]],
     );
 }
 
@@ -555,10 +556,10 @@ impl Foo {
 }
 "#,
         expect![[r#"
-                ev Bar    Bar
+            me foo(…) fn(self)
-                ev Baz    Baz
+            ev Bar    Bar
-                me foo(…) fn(self)
+            ev Baz    Baz
-            "#]],
+        "#]],
     );
 }
 
@@ -1399,7 +1400,7 @@ fn main() {
     bar.b$0
 }
 "#,
-        CompletionItemKind::Method,
+        CompletionItemKind::SymbolKind(SymbolKind::Method),
         expect!("const fn(&'foo mut self, &Foo) -> !"),
         expect!("pub const fn baz<'foo>(&'foo mut self, x: &'foo Foo) -> !"),
     );

src/tools/rust-analyzer/crates/ide-completion/src/tests/type_pos.rs

@@ -20,8 +20,8 @@ struct Foo<'lt, T, const C: usize> {
             en Enum      Enum
             ma makro!(…) macro_rules! makro
             md module
-            sp Self      Foo<'_, {unknown}, _>
+            sp Self      Foo<'static, {unknown}, _>
-            st Foo<…>    Foo<'_, {unknown}, _>
+            st Foo<…>    Foo<'static, {unknown}, _>
             st Record    Record
             st Tuple     Tuple
             st Unit      Unit
@@ -45,8 +45,8 @@ struct Foo<'lt, T, const C: usize>(f$0);
             en Enum       Enum
             ma makro!(…)  macro_rules! makro
             md module
-            sp Self       Foo<'_, {unknown}, _>
+            sp Self       Foo<'static, {unknown}, _>
-            st Foo<…>     Foo<'_, {unknown}, _>
+            st Foo<…>     Foo<'static, {unknown}, _>
             st Record     Record
             st Tuple      Tuple
             st Unit       Unit

src/tools/rust-analyzer/crates/ide-db/src/lib.rs

@@ -346,6 +346,7 @@ pub enum SymbolKind {
     Enum,
     Field,
     Function,
+    Method,
     Impl,
     Label,
     LifetimeParam,

src/tools/rust-analyzer/crates/ide-diagnostics/Cargo.toml

@@ -26,6 +26,7 @@ text-edit.workspace = true
 cfg.workspace = true
 hir.workspace = true
 ide-db.workspace = true
+paths.workspace = true
 
 [dev-dependencies]
 expect-test = "1.4.0"

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/missing_match_arms.rs

@@ -23,6 +23,7 @@ mod tests {
         },
         DiagnosticsConfig,
     };
+    use test_utils::skip_slow_tests;
 
     #[track_caller]
     fn check_diagnostics_no_bails(ra_fixture: &str) {
@@ -1004,6 +1005,32 @@ fn f() {
         );
     }
 
+    #[test]
+    fn exponential_match() {
+        if skip_slow_tests() {
+            return;
+        }
+        // Constructs a match where match checking takes exponential time. Ensures we bail early.
+        use std::fmt::Write;
+        let struct_arity = 50;
+        let mut code = String::new();
+        write!(code, "struct BigStruct {{").unwrap();
+        for i in 0..struct_arity {
+            write!(code, "  field{i}: bool,").unwrap();
+        }
+        write!(code, "}}").unwrap();
+        write!(code, "fn big_match(s: BigStruct) {{").unwrap();
+        write!(code, "  match s {{").unwrap();
+        for i in 0..struct_arity {
+            write!(code, "    BigStruct {{ field{i}: true, ..}} => {{}},").unwrap();
+            write!(code, "    BigStruct {{ field{i}: false, ..}} => {{}},").unwrap();
+        }
+        write!(code, "    _ => {{}},").unwrap();
+        write!(code, "  }}").unwrap();
+        write!(code, "}}").unwrap();
+        check_diagnostics_no_bails(&code);
+    }
+
     mod rust_unstable {
         use super::*;
 

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/mutability_errors.rs

@@ -7,7 +7,11 @@ use crate::{fix, Diagnostic, DiagnosticCode, DiagnosticsContext};
 // Diagnostic: need-mut
 //
 // This diagnostic is triggered on mutating an immutable variable.
-pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Diagnostic {
+pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Option<Diagnostic> {
+    if d.span.file_id.macro_file().is_some() {
+        // FIXME: Our infra can't handle allow from within macro expansions rn
+        return None;
+    }
     let fixes = (|| {
         if d.local.is_ref(ctx.sema.db) {
             // There is no simple way to add `mut` to `ref x` and `ref mut x`
@@ -29,24 +33,30 @@ pub(crate) fn need_mut(ctx: &DiagnosticsContext<'_>, d: &hir::NeedMut) -> Diagno
             use_range,
         )])
     })();
-    Diagnostic::new_with_syntax_node_ptr(
+    Some(
-        ctx,
+        Diagnostic::new_with_syntax_node_ptr(
-        // FIXME: `E0384` is not the only error that this diagnostic handles
+            ctx,
-        DiagnosticCode::RustcHardError("E0384"),
+            // FIXME: `E0384` is not the only error that this diagnostic handles
-        format!(
+            DiagnosticCode::RustcHardError("E0384"),
-            "cannot mutate immutable variable `{}`",
+            format!(
-            d.local.name(ctx.sema.db).display(ctx.sema.db)
+                "cannot mutate immutable variable `{}`",
-        ),
+                d.local.name(ctx.sema.db).display(ctx.sema.db)
-        d.span,
+            ),
+            d.span,
+        )
+        .with_fixes(fixes),
     )
-    .with_fixes(fixes)
 }
 
 // Diagnostic: unused-mut
 //
 // This diagnostic is triggered when a mutable variable isn't actually mutated.
-pub(crate) fn unused_mut(ctx: &DiagnosticsContext<'_>, d: &hir::UnusedMut) -> Diagnostic {
+pub(crate) fn unused_mut(ctx: &DiagnosticsContext<'_>, d: &hir::UnusedMut) -> Option<Diagnostic> {
     let ast = d.local.primary_source(ctx.sema.db).syntax_ptr();
+    if ast.file_id.macro_file().is_some() {
+        // FIXME: Our infra can't handle allow from within macro expansions rn
+        return None;
+    }
     let fixes = (|| {
         let file_id = ast.file_id.file_id()?;
         let mut edit_builder = TextEdit::builder();
@@ -70,14 +80,16 @@ pub(crate) fn unused_mut(ctx: &DiagnosticsContext<'_>, d: &hir::UnusedMut) -> Di
         )])
     })();
     let ast = d.local.primary_source(ctx.sema.db).syntax_ptr();
-    Diagnostic::new_with_syntax_node_ptr(
+    Some(
-        ctx,
+        Diagnostic::new_with_syntax_node_ptr(
-        DiagnosticCode::RustcLint("unused_mut"),
+            ctx,
-        "variable does not need to be mutable",
+            DiagnosticCode::RustcLint("unused_mut"),
-        ast,
+            "variable does not need to be mutable",
+            ast,
+        )
+        .experimental() // Not supporting `#[allow(unused_mut)]` in proc macros leads to false positive.
+        .with_fixes(fixes),
     )
-    .experimental() // Not supporting `#[allow(unused_mut)]` in proc macros leads to false positive.
-    .with_fixes(fixes)
 }
 
 pub(super) fn token(parent: &SyntaxNode, kind: SyntaxKind) -> Option<SyntaxToken> {

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/remove_trailing_return.rs

@@ -12,7 +12,12 @@ use crate::{adjusted_display_range, fix, Diagnostic, DiagnosticCode, Diagnostics
 pub(crate) fn remove_trailing_return(
     ctx: &DiagnosticsContext<'_>,
     d: &RemoveTrailingReturn,
-) -> Diagnostic {
+) -> Option<Diagnostic> {
+    if d.return_expr.file_id.macro_file().is_some() {
+        // FIXME: Our infra can't handle allow from within macro expansions rn
+        return None;
+    }
+
     let display_range = adjusted_display_range(ctx, d.return_expr, &|return_expr| {
         return_expr
             .syntax()
@@ -20,12 +25,14 @@ pub(crate) fn remove_trailing_return(
             .and_then(ast::ExprStmt::cast)
             .map(|stmt| stmt.syntax().text_range())
     });
-    Diagnostic::new(
+    Some(
-        DiagnosticCode::Clippy("needless_return"),
+        Diagnostic::new(
-        "replace return <expr>; with <expr>",
+            DiagnosticCode::Clippy("needless_return"),
-        display_range,
+            "replace return <expr>; with <expr>",
+            display_range,
+        )
+        .with_fixes(fixes(ctx, d)),
     )
-    .with_fixes(fixes(ctx, d))
 }
 
 fn fixes(ctx: &DiagnosticsContext<'_>, d: &RemoveTrailingReturn) -> Option<Vec<Assist>> {

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/remove_unnecessary_else.rs

@@ -21,23 +21,30 @@ use crate::{
 pub(crate) fn remove_unnecessary_else(
     ctx: &DiagnosticsContext<'_>,
     d: &RemoveUnnecessaryElse,
-) -> Diagnostic {
+) -> Option<Diagnostic> {
+    if d.if_expr.file_id.macro_file().is_some() {
+        // FIXME: Our infra can't handle allow from within macro expansions rn
+        return None;
+    }
+
     let display_range = adjusted_display_range(ctx, d.if_expr, &|if_expr| {
         if_expr.else_token().as_ref().map(SyntaxToken::text_range)
     });
-    Diagnostic::new(
+    Some(
-        DiagnosticCode::Ra("remove-unnecessary-else", Severity::WeakWarning),
+        Diagnostic::new(
-        "remove unnecessary else block",
+            DiagnosticCode::Ra("remove-unnecessary-else", Severity::WeakWarning),
-        display_range,
+            "remove unnecessary else block",
+            display_range,
+        )
+        .experimental()
+        .with_fixes(fixes(ctx, d)),
     )
-    .experimental()
-    .with_fixes(fixes(ctx, d))
 }
 
 fn fixes(ctx: &DiagnosticsContext<'_>, d: &RemoveUnnecessaryElse) -> Option<Vec<Assist>> {
     let root = ctx.sema.db.parse_or_expand(d.if_expr.file_id);
     let if_expr = d.if_expr.value.to_node(&root);
-    let if_expr = ctx.sema.original_ast_node(if_expr.clone())?;
+    let if_expr = ctx.sema.original_ast_node(if_expr)?;
 
     let mut indent = IndentLevel::from_node(if_expr.syntax());
     let has_parent_if_expr = if_expr.syntax().parent().and_then(ast::IfExpr::cast).is_some();

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unlinked_file.rs

@@ -8,6 +8,7 @@ use ide_db::{
     source_change::SourceChange,
     RootDatabase,
 };
+use paths::Utf8Component;
 use syntax::{
     ast::{self, edit::IndentLevel, HasModuleItem, HasName},
     AstNode, TextRange,
@@ -84,10 +85,10 @@ fn fixes(ctx: &DiagnosticsContext<'_>, file_id: FileId) -> Option<Vec<Assist>> {
 
         // try resolving the relative difference of the paths as inline modules
         let mut current = root_module;
-        for ele in rel.as_ref().components() {
+        for ele in rel.as_utf8_path().components() {
             let seg = match ele {
-                std::path::Component::Normal(seg) => seg.to_str()?,
+                Utf8Component::Normal(seg) => seg,
-                std::path::Component::RootDir => continue,
+                Utf8Component::RootDir => continue,
                 // shouldn't occur
                 _ => continue 'crates,
             };

src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unused_variables.rs

@@ -14,18 +14,24 @@ use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext};
 pub(crate) fn unused_variables(
     ctx: &DiagnosticsContext<'_>,
     d: &hir::UnusedVariable,
-) -> Diagnostic {
+) -> Option<Diagnostic> {
     let ast = d.local.primary_source(ctx.sema.db).syntax_ptr();
+    if ast.file_id.macro_file().is_some() {
+        // FIXME: Our infra can't handle allow from within macro expansions rn
+        return None;
+    }
     let diagnostic_range = ctx.sema.diagnostics_display_range(ast);
     let var_name = d.local.primary_source(ctx.sema.db).syntax().to_string();
-    Diagnostic::new_with_syntax_node_ptr(
+    Some(
-        ctx,
+        Diagnostic::new_with_syntax_node_ptr(
-        DiagnosticCode::RustcLint("unused_variables"),
+            ctx,
-        "unused variable",
+            DiagnosticCode::RustcLint("unused_variables"),
-        ast,
+            "unused variable",
+            ast,
+        )
+        .with_fixes(fixes(&var_name, diagnostic_range, ast.file_id.is_macro()))
+        .experimental(),
     )
-    .with_fixes(fixes(&var_name, diagnostic_range, ast.file_id.is_macro()))
-    .experimental()
 }
 
 fn fixes(var_name: &String, diagnostic_range: FileRange, is_in_marco: bool) -> Option<Vec<Assist>> {
@@ -47,7 +53,7 @@ fn fixes(var_name: &String, diagnostic_range: FileRange, is_in_marco: bool) -> O
 
 #[cfg(test)]
 mod tests {
-    use crate::tests::{check_diagnostics, check_fix, check_no_fix};
+    use crate::tests::{check_diagnostics, check_fix};
 
     #[test]
     fn unused_variables_simple() {
@@ -193,7 +199,7 @@ fn main() {
 
     #[test]
     fn no_fix_for_marco() {
-        check_no_fix(
+        check_diagnostics(
             r#"
 macro_rules! my_macro {
     () => {
@@ -202,7 +208,7 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    $0my_macro!();
+    my_macro!();
 }
 "#,
         );

src/tools/rust-analyzer/crates/ide-diagnostics/src/lib.rs

@@ -330,7 +330,6 @@ pub fn diagnostics(
     }
 
     for diag in diags {
-        #[rustfmt::skip]
         let d = match diag {
             AnyDiagnostic::ExpectedFunction(d) => handlers::expected_function::expected_function(&ctx, &d),
             AnyDiagnostic::InactiveCode(d) => match handlers::inactive_code::inactive_code(&ctx, &d) {
@@ -361,7 +360,10 @@ pub fn diagnostics(
             AnyDiagnostic::MissingMatchArms(d) => handlers::missing_match_arms::missing_match_arms(&ctx, &d),
             AnyDiagnostic::MissingUnsafe(d) => handlers::missing_unsafe::missing_unsafe(&ctx, &d),
             AnyDiagnostic::MovedOutOfRef(d) => handlers::moved_out_of_ref::moved_out_of_ref(&ctx, &d),
-            AnyDiagnostic::NeedMut(d) => handlers::mutability_errors::need_mut(&ctx, &d),
+            AnyDiagnostic::NeedMut(d) => match handlers::mutability_errors::need_mut(&ctx, &d) {
+                Some(it) => it,
+                None => continue,
+            },
             AnyDiagnostic::NonExhaustiveLet(d) => handlers::non_exhaustive_let::non_exhaustive_let(&ctx, &d),
             AnyDiagnostic::NoSuchField(d) => handlers::no_such_field::no_such_field(&ctx, &d),
             AnyDiagnostic::PrivateAssocItem(d) => handlers::private_assoc_item::private_assoc_item(&ctx, &d),
@@ -385,12 +387,24 @@ pub fn diagnostics(
             AnyDiagnostic::UnresolvedMethodCall(d) => handlers::unresolved_method::unresolved_method(&ctx, &d),
             AnyDiagnostic::UnresolvedModule(d) => handlers::unresolved_module::unresolved_module(&ctx, &d),
             AnyDiagnostic::UnresolvedProcMacro(d) => handlers::unresolved_proc_macro::unresolved_proc_macro(&ctx, &d, config.proc_macros_enabled, config.proc_attr_macros_enabled),
-            AnyDiagnostic::UnusedMut(d) => handlers::mutability_errors::unused_mut(&ctx, &d),
+            AnyDiagnostic::UnusedMut(d) => match handlers::mutability_errors::unused_mut(&ctx, &d) {
-            AnyDiagnostic::UnusedVariable(d) => handlers::unused_variables::unused_variables(&ctx, &d),
+                Some(it) => it,
+                None => continue,
+            },
+            AnyDiagnostic::UnusedVariable(d) => match handlers::unused_variables::unused_variables(&ctx, &d) {
+                Some(it) => it,
+                None => continue,
+            },
             AnyDiagnostic::BreakOutsideOfLoop(d) => handlers::break_outside_of_loop::break_outside_of_loop(&ctx, &d),
             AnyDiagnostic::MismatchedTupleStructPatArgCount(d) => handlers::mismatched_arg_count::mismatched_tuple_struct_pat_arg_count(&ctx, &d),
-            AnyDiagnostic::RemoveTrailingReturn(d) => handlers::remove_trailing_return::remove_trailing_return(&ctx, &d),
+            AnyDiagnostic::RemoveTrailingReturn(d) => match handlers::remove_trailing_return::remove_trailing_return(&ctx, &d) {
-            AnyDiagnostic::RemoveUnnecessaryElse(d) => handlers::remove_unnecessary_else::remove_unnecessary_else(&ctx, &d),
+                Some(it) => it,
+                None => continue,
+            },
+            AnyDiagnostic::RemoveUnnecessaryElse(d) => match handlers::remove_unnecessary_else::remove_unnecessary_else(&ctx, &d) {
+                Some(it) => it,
+                None => continue,
+            },
         };
         res.push(d)
     }
@@ -399,9 +413,9 @@ pub fn diagnostics(
         .iter_mut()
         .filter_map(|it| {
             Some((
-                it.main_node
+                it.main_node.map(|ptr| {
-                    .map(|ptr| ptr.map(|node| node.to_node(&ctx.sema.parse_or_expand(ptr.file_id))))
+                    ptr.map(|node| node.to_node(&ctx.sema.parse_or_expand(ptr.file_id)))
-                    .clone()?,
+                })?,
                 it,
             ))
         })

src/tools/rust-analyzer/crates/ide-diagnostics/src/tests.rs

@@ -283,6 +283,10 @@ fn test_disabled_diagnostics() {
 
 #[test]
 fn minicore_smoke_test() {
+    if test_utils::skip_slow_tests() {
+        return;
+    }
+
     fn check(minicore: MiniCore) {
         let source = minicore.source_code();
         let mut config = DiagnosticsConfig::test_sample();

src/tools/rust-analyzer/crates/ide/Cargo.toml

@@ -36,6 +36,7 @@ ide-ssr.workspace = true
 profile.workspace = true
 stdx.workspace = true
 syntax.workspace = true
+span.workspace = true
 text-edit.workspace = true
 # ide should depend only on the top-level `hir` package. if you need
 # something from some `hir-xxx` subpackage, reexport the API via `hir`.

src/tools/rust-analyzer/crates/ide/src/doc_links.rs

@@ -5,8 +5,6 @@ mod tests;
 
 mod intra_doc_links;
 
-use std::ffi::OsStr;
-
 use pulldown_cmark::{BrokenLink, CowStr, Event, InlineStr, LinkType, Options, Parser, Tag};
 use pulldown_cmark_to_cmark::{cmark_resume_with_options, Options as CMarkOptions};
 use stdx::format_to;
@@ -134,8 +132,8 @@ pub(crate) fn remove_links(markdown: &str) -> String {
 pub(crate) fn external_docs(
     db: &RootDatabase,
     FilePosition { file_id, offset }: FilePosition,
-    target_dir: Option<&OsStr>,
+    target_dir: Option<&str>,
-    sysroot: Option<&OsStr>,
+    sysroot: Option<&str>,
 ) -> Option<DocumentationLinks> {
     let sema = &Semantics::new(db);
     let file = sema.parse(file_id).syntax().clone();
@@ -331,8 +329,8 @@ fn broken_link_clone_cb(link: BrokenLink<'_>) -> Option<(CowStr<'_>, CowStr<'_>)
 fn get_doc_links(
     db: &RootDatabase,
     def: Definition,
-    target_dir: Option<&OsStr>,
+    target_dir: Option<&str>,
-    sysroot: Option<&OsStr>,
+    sysroot: Option<&str>,
 ) -> DocumentationLinks {
     let join_url = |base_url: Option<Url>, path: &str| -> Option<Url> {
         base_url.and_then(|url| url.join(path).ok())
@@ -479,15 +477,13 @@ fn map_links<'e>(
 fn get_doc_base_urls(
     db: &RootDatabase,
     def: Definition,
-    target_dir: Option<&OsStr>,
+    target_dir: Option<&str>,
-    sysroot: Option<&OsStr>,
+    sysroot: Option<&str>,
 ) -> (Option<Url>, Option<Url>) {
     let local_doc = target_dir
-        .and_then(|path| path.to_str())
         .and_then(|path| Url::parse(&format!("file:///{path}/")).ok())
         .and_then(|it| it.join("doc/").ok());
     let system_doc = sysroot
-        .and_then(|it| it.to_str())
         .map(|sysroot| format!("file:///{sysroot}/share/doc/rust/html/"))
         .and_then(|it| Url::parse(&it).ok());
 

src/tools/rust-analyzer/crates/ide/src/doc_links/tests.rs

@@ -1,4 +1,4 @@
-use std::{ffi::OsStr, iter};
+use std::iter;
 
 use expect_test::{expect, Expect};
 use hir::Semantics;
@@ -18,10 +18,10 @@ use crate::{
 
 fn check_external_docs(
     ra_fixture: &str,
-    target_dir: Option<&OsStr>,
+    target_dir: Option<&str>,
     expect_web_url: Option<Expect>,
     expect_local_url: Option<Expect>,
-    sysroot: Option<&OsStr>,
+    sysroot: Option<&str>,
 ) {
     let (analysis, position) = fixture::position(ra_fixture);
     let links = analysis.external_docs(position, target_dir, sysroot).unwrap();
@@ -127,10 +127,10 @@ fn external_docs_doc_builtin_type() {
 //- /main.rs crate:foo
 let x: u3$02 = 0;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://doc.rust-lang.org/nightly/core/primitive.u32.html"#]]),
         Some(expect![[r#"file:///sysroot/share/doc/rust/html/core/primitive.u32.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -143,10 +143,10 @@ use foo$0::Foo;
 //- /lib.rs crate:foo
 pub struct Foo;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/index.html"#]]),
         Some(expect![[r#"file:///home/user/project/doc/foo/index.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -157,10 +157,10 @@ fn external_docs_doc_url_std_crate() {
 //- /main.rs crate:std
 use self$0;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect!["https://doc.rust-lang.org/stable/std/index.html"]),
         Some(expect!["file:///sysroot/share/doc/rust/html/std/index.html"]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -171,10 +171,10 @@ fn external_docs_doc_url_struct() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///home/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -185,10 +185,10 @@ fn external_docs_doc_url_windows_backslash_path() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new(r"C:\Users\user\project")),
+        Some(r"C:\Users\user\project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///C:/Users/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -199,10 +199,10 @@ fn external_docs_doc_url_windows_slash_path() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new(r"C:/Users/user/project")),
+        Some("C:/Users/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///C:/Users/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 

src/tools/rust-analyzer/crates/ide/src/file_structure.rs

@@ -134,15 +134,22 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
                 if let Some(type_param_list) = it.generic_param_list() {
                     collapse_ws(type_param_list.syntax(), &mut detail);
                 }
-                if let Some(param_list) = it.param_list() {
+                let has_self_param = if let Some(param_list) = it.param_list() {
                     collapse_ws(param_list.syntax(), &mut detail);
-                }
+                    param_list.self_param().is_some()
+                } else {
+                    false
+                };
                 if let Some(ret_type) = it.ret_type() {
                     detail.push(' ');
                     collapse_ws(ret_type.syntax(), &mut detail);
                 }
 
-                decl_with_detail(&it, Some(detail), StructureNodeKind::SymbolKind(SymbolKind::Function))
+                decl_with_detail(&it, Some(detail), StructureNodeKind::SymbolKind(if has_self_param {
+                    SymbolKind::Method
+                } else {
+                    SymbolKind::Function
+                }))
             },
             ast::Struct(it) => decl(it, StructureNodeKind::SymbolKind(SymbolKind::Struct)),
             ast::Union(it) => decl(it, StructureNodeKind::SymbolKind(SymbolKind::Union)),

src/tools/rust-analyzer/crates/ide/src/goto_implementation.rs

@@ -337,6 +337,77 @@ impl Tr for S {
     const C: usize = 4;
         //^
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_adt_implementation_inside_block() {
+        check(
+            r#"
+//- minicore: copy, derive
+trait Bar {}
+
+fn test() {
+    #[derive(Copy)]
+  //^^^^^^^^^^^^^^^
+    struct Foo$0;
+
+    impl Foo {}
+       //^^^
+
+    trait Baz {}
+
+    impl Bar for Foo {}
+               //^^^
+
+    impl Baz for Foo {}
+               //^^^
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_trait_implementation_inside_block() {
+        check(
+            r#"
+struct Bar;
+
+fn test() {
+    trait Foo$0 {}
+
+    struct Baz;
+
+    impl Foo for Bar {}
+               //^^^
+
+    impl Foo for Baz {}
+               //^^^
+}
+"#,
+        );
+        check(
+            r#"
+struct Bar;
+
+fn test() {
+    trait Foo {
+        fn foo$0() {}
+    }
+
+    struct Baz;
+
+    impl Foo for Bar {
+        fn foo() {}
+         //^^^
+    }
+
+    impl Foo for Baz {
+        fn foo() {}
+         //^^^
+    }
+}
 "#,
         );
     }

src/tools/rust-analyzer/crates/ide/src/hover.rs

@@ -33,6 +33,7 @@ pub struct HoverConfig {
     pub keywords: bool,
     pub format: HoverDocFormat,
     pub max_trait_assoc_items_count: Option<usize>,
+    pub max_struct_field_count: Option<usize>,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]

src/tools/rust-analyzer/crates/ide/src/hover/render.rs

@@ -410,6 +410,9 @@ pub(super) fn definition(
         Definition::Trait(trait_) => {
             trait_.display_limited(db, config.max_trait_assoc_items_count).to_string()
         }
+        Definition::Adt(Adt::Struct(struct_)) => {
+            struct_.display_limited(db, config.max_struct_field_count).to_string()
+        }
         _ => def.label(db),
     };
     let docs = def.docs(db, famous_defs);

src/tools/rust-analyzer/crates/ide/src/hover/tests.rs

@@ -18,6 +18,7 @@ const HOVER_BASE_CONFIG: HoverConfig = HoverConfig {
     format: HoverDocFormat::Markdown,
     keywords: true,
     max_trait_assoc_items_count: None,
+    max_struct_field_count: None,
 };
 
 fn check_hover_no_result(ra_fixture: &str) {
@@ -49,6 +50,28 @@ fn check(ra_fixture: &str, expect: Expect) {
     expect.assert_eq(&actual)
 }
 
+#[track_caller]
+fn check_hover_struct_limit(count: usize, ra_fixture: &str, expect: Expect) {
+    let (analysis, position) = fixture::position(ra_fixture);
+    let hover = analysis
+        .hover(
+            &HoverConfig {
+                links_in_hover: true,
+                max_struct_field_count: Some(count),
+                ..HOVER_BASE_CONFIG
+            },
+            FileRange { file_id: position.file_id, range: TextRange::empty(position.offset) },
+        )
+        .unwrap()
+        .unwrap();
+
+    let content = analysis.db.file_text(position.file_id);
+    let hovered_element = &content[hover.range];
+
+    let actual = format!("*{hovered_element}*\n{}\n", hover.info.markup);
+    expect.assert_eq(&actual)
+}
+
 #[track_caller]
 fn check_assoc_count(count: usize, ra_fixture: &str, expect: Expect) {
     let (analysis, position) = fixture::position(ra_fixture);
@@ -853,9 +876,7 @@ struct Foo$0 { field: u32 }
 
             ```rust
             // size = 4, align = 4
-            struct Foo {
+            struct Foo
-                field: u32,
-            }
             ```
         "#]],
     );
@@ -875,8 +896,74 @@ struct Foo$0 where u32: Copy { field: u32 }
             struct Foo
             where
                 u32: Copy,
-            {
+            ```
-                field: u32,
+        "#]],
+    );
+}
+
+#[test]
+fn hover_record_struct_limit() {
+    check_hover_struct_limit(
+        3,
+        r#"
+    struct Foo$0 { a: u32, b: i32, c: i32 }
+    "#,
+        expect![[r#"
+            *Foo*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            // size = 12 (0xC), align = 4
+            struct Foo  {
+                a: u32,
+                b: i32,
+                c: i32,
+            }
+            ```
+        "#]],
+    );
+    check_hover_struct_limit(
+        3,
+        r#"
+    struct Foo$0 { a: u32 }
+    "#,
+        expect![[r#"
+            *Foo*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            // size = 4, align = 4
+            struct Foo  {
+                a: u32,
+            }
+            ```
+        "#]],
+    );
+    check_hover_struct_limit(
+        3,
+        r#"
+    struct Foo$0 { a: u32, b: i32, c: i32, d: u32 }
+    "#,
+        expect![[r#"
+            *Foo*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            // size = 16 (0x10), align = 4
+            struct Foo  {
+                a: u32,
+                b: i32,
+                c: i32,
+                /* … */
             }
             ```
         "#]],
@@ -1344,9 +1431,7 @@ impl Thing {
                 ```
 
                 ```rust
-                struct Thing {
+                struct Thing
-                    x: u32,
-                }
                 ```
             "#]],
     );
@@ -1365,9 +1450,7 @@ impl Thing {
                 ```
 
                 ```rust
-                struct Thing {
+                struct Thing
-                    x: u32,
-                }
                 ```
             "#]],
     );
@@ -2599,7 +2682,7 @@ fn main() { let s$0t = S{ f1:0 }; }
                                     focus_range: 7..8,
                                     name: "S",
                                     kind: Struct,
-                                    description: "struct S {\n    f1: u32,\n}",
+                                    description: "struct S",
                                 },
                             },
                         ],
@@ -2645,7 +2728,7 @@ fn main() { let s$0t = S{ f1:Arg(0) }; }
                                 focus_range: 24..25,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S<T> {\n    f1: T,\n}",
+                                description: "struct S<T>",
                             },
                         },
                     ],
@@ -2704,7 +2787,7 @@ fn main() { let s$0t = S{ f1: S{ f1: Arg(0) } }; }
                                 focus_range: 24..25,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S<T> {\n    f1: T,\n}",
+                                description: "struct S<T>",
                             },
                         },
                     ],
@@ -2957,7 +3040,7 @@ fn main() { let s$0t = foo(); }
                                 focus_range: 39..41,
                                 name: "S1",
                                 kind: Struct,
-                                description: "struct S1 {}",
+                                description: "struct S1",
                             },
                         },
                         HoverGotoTypeData {
@@ -2970,7 +3053,7 @@ fn main() { let s$0t = foo(); }
                                 focus_range: 52..54,
                                 name: "S2",
                                 kind: Struct,
-                                description: "struct S2 {}",
+                                description: "struct S2",
                             },
                         },
                     ],
@@ -3061,7 +3144,7 @@ fn foo(ar$0g: &impl Foo + Bar<S>) {}
                                 focus_range: 36..37,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S {}",
+                                description: "struct S",
                             },
                         },
                     ],
@@ -3161,7 +3244,7 @@ fn foo(ar$0g: &impl Foo<S>) {}
                                 focus_range: 23..24,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S {}",
+                                description: "struct S",
                             },
                         },
                     ],
@@ -3198,7 +3281,7 @@ fn main() { let s$0t = foo(); }
                                 focus_range: 49..50,
                                 name: "B",
                                 kind: Struct,
-                                description: "struct B<T> {}",
+                                description: "struct B<T>",
                             },
                         },
                         HoverGotoTypeData {
@@ -3287,7 +3370,7 @@ fn foo(ar$0g: &dyn Foo<S>) {}
                                 focus_range: 23..24,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S {}",
+                                description: "struct S",
                             },
                         },
                     ],
@@ -3322,7 +3405,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                 focus_range: 50..51,
                                 name: "B",
                                 kind: Struct,
-                                description: "struct B<T> {}",
+                                description: "struct B<T>",
                             },
                         },
                         HoverGotoTypeData {
@@ -3361,7 +3444,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                 focus_range: 65..66,
                                 name: "S",
                                 kind: Struct,
-                                description: "struct S {}",
+                                description: "struct S",
                             },
                         },
                     ],
@@ -5105,6 +5188,32 @@ fn foo(e: E) {
     );
 }
 
+#[test]
+fn hover_const_value() {
+    check(
+        r#"
+pub enum AA {
+    BB,
+}
+const CONST: AA = AA::BB;
+pub fn the_function() -> AA {
+    CON$0ST
+}
+"#,
+        expect![[r#"
+            *CONST*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            const CONST: AA = BB
+            ```
+        "#]],
+    );
+}
+
 #[test]
 fn array_repeat_exp() {
     check(
@@ -7747,3 +7856,25 @@ impl Iterator for S {
         "#]],
     );
 }
+
+#[test]
+fn hover_lifetime_regression_16963() {
+    check(
+        r#"
+struct Pedro$0<'a> {
+    hola: &'a str
+}
+"#,
+        expect![[r#"
+            *Pedro*
+
+            ```rust
+            test
+            ```
+
+            ```rust
+            struct Pedro<'a>
+            ```
+        "#]],
+    )
+}

src/tools/rust-analyzer/crates/ide/src/inlay_hints.rs

@@ -1,5 +1,6 @@
 use std::{
     fmt::{self, Write},
+    hash::{BuildHasher, BuildHasherDefault},
     mem::take,
 };
 
@@ -8,7 +9,7 @@ use hir::{
     known, ClosureStyle, HasVisibility, HirDisplay, HirDisplayError, HirWrite, ModuleDef,
     ModuleDefId, Semantics,
 };
-use ide_db::{base_db::FileRange, famous_defs::FamousDefs, RootDatabase};
+use ide_db::{base_db::FileRange, famous_defs::FamousDefs, FxHasher, RootDatabase};
 use itertools::Itertools;
 use smallvec::{smallvec, SmallVec};
 use stdx::never;
@@ -116,7 +117,7 @@ pub enum AdjustmentHintsMode {
     PreferPostfix,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
 pub enum InlayKind {
     Adjustment,
     BindingMode,
@@ -132,7 +133,7 @@ pub enum InlayKind {
     RangeExclusive,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Hash)]
 pub enum InlayHintPosition {
     Before,
     After,
@@ -151,13 +152,23 @@ pub struct InlayHint {
     pub label: InlayHintLabel,
     /// Text edit to apply when "accepting" this inlay hint.
     pub text_edit: Option<TextEdit>,
-    pub needs_resolve: bool,
+}
+
+impl std::hash::Hash for InlayHint {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.range.hash(state);
+        self.position.hash(state);
+        self.pad_left.hash(state);
+        self.pad_right.hash(state);
+        self.kind.hash(state);
+        self.label.hash(state);
+        self.text_edit.is_some().hash(state);
+    }
 }
 
 impl InlayHint {
     fn closing_paren_after(kind: InlayKind, range: TextRange) -> InlayHint {
         InlayHint {
-            needs_resolve: false,
             range,
             kind,
             label: InlayHintLabel::from(")"),
@@ -167,9 +178,9 @@ impl InlayHint {
             pad_right: false,
         }
     }
+
     fn opening_paren_before(kind: InlayKind, range: TextRange) -> InlayHint {
         InlayHint {
-            needs_resolve: false,
             range,
             kind,
             label: InlayHintLabel::from("("),
@@ -179,15 +190,19 @@ impl InlayHint {
             pad_right: false,
         }
     }
+
+    pub fn needs_resolve(&self) -> bool {
+        self.text_edit.is_some() || self.label.needs_resolve()
+    }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Hash)]
 pub enum InlayTooltip {
     String(String),
     Markdown(String),
 }
 
-#[derive(Default)]
+#[derive(Default, Hash)]
 pub struct InlayHintLabel {
     pub parts: SmallVec<[InlayHintLabelPart; 1]>,
 }
@@ -265,6 +280,7 @@ impl fmt::Debug for InlayHintLabel {
     }
 }
 
+#[derive(Hash)]
 pub struct InlayHintLabelPart {
     pub text: String,
     /// Source location represented by this label part. The client will use this to fetch the part's
@@ -313,9 +329,7 @@ impl fmt::Write for InlayHintLabelBuilder<'_> {
 
 impl HirWrite for InlayHintLabelBuilder<'_> {
     fn start_location_link(&mut self, def: ModuleDefId) {
-        if self.location.is_some() {
+        never!(self.location.is_some(), "location link is already started");
-            never!("location link is already started");
-        }
         self.make_new_part();
         let Some(location) = ModuleDef::from(def).try_to_nav(self.db) else { return };
         let location = location.call_site();
@@ -425,11 +439,6 @@ fn ty_to_text_edit(
     Some(builder.finish())
 }
 
-pub enum RangeLimit {
-    Fixed(TextRange),
-    NearestParent(TextSize),
-}
-
 // Feature: Inlay Hints
 //
 // rust-analyzer shows additional information inline with the source code.
@@ -451,7 +460,7 @@ pub enum RangeLimit {
 pub(crate) fn inlay_hints(
     db: &RootDatabase,
     file_id: FileId,
-    range_limit: Option<RangeLimit>,
+    range_limit: Option<TextRange>,
     config: &InlayHintsConfig,
 ) -> Vec<InlayHint> {
     let _p = tracing::span!(tracing::Level::INFO, "inlay_hints").entered();
@@ -466,31 +475,13 @@ pub(crate) fn inlay_hints(
 
         let hints = |node| hints(&mut acc, &famous_defs, config, file_id, node);
         match range_limit {
-            Some(RangeLimit::Fixed(range)) => match file.covering_element(range) {
+            Some(range) => match file.covering_element(range) {
                 NodeOrToken::Token(_) => return acc,
                 NodeOrToken::Node(n) => n
                     .descendants()
                     .filter(|descendant| range.intersect(descendant.text_range()).is_some())
                     .for_each(hints),
             },
-            Some(RangeLimit::NearestParent(position)) => {
-                match file.token_at_offset(position).left_biased() {
-                    Some(token) => {
-                        if let Some(parent_block) =
-                            token.parent_ancestors().find_map(ast::BlockExpr::cast)
-                        {
-                            parent_block.syntax().descendants().for_each(hints)
-                        } else if let Some(parent_item) =
-                            token.parent_ancestors().find_map(ast::Item::cast)
-                        {
-                            parent_item.syntax().descendants().for_each(hints)
-                        } else {
-                            return acc;
-                        }
-                    }
-                    None => return acc,
-                }
-            }
             None => file.descendants().for_each(hints),
         };
     }
@@ -498,6 +489,39 @@ pub(crate) fn inlay_hints(
     acc
 }
 
+pub(crate) fn inlay_hints_resolve(
+    db: &RootDatabase,
+    file_id: FileId,
+    position: TextSize,
+    hash: u64,
+    config: &InlayHintsConfig,
+) -> Option<InlayHint> {
+    let _p = tracing::span!(tracing::Level::INFO, "inlay_hints").entered();
+    let sema = Semantics::new(db);
+    let file = sema.parse(file_id);
+    let file = file.syntax();
+
+    let scope = sema.scope(file)?;
+    let famous_defs = FamousDefs(&sema, scope.krate());
+    let mut acc = Vec::new();
+
+    let hints = |node| hints(&mut acc, &famous_defs, config, file_id, node);
+    match file.token_at_offset(position).left_biased() {
+        Some(token) => {
+            if let Some(parent_block) = token.parent_ancestors().find_map(ast::BlockExpr::cast) {
+                parent_block.syntax().descendants().for_each(hints)
+            } else if let Some(parent_item) = token.parent_ancestors().find_map(ast::Item::cast) {
+                parent_item.syntax().descendants().for_each(hints)
+            } else {
+                return None;
+            }
+        }
+        None => return None,
+    }
+
+    acc.into_iter().find(|hint| BuildHasherDefault::<FxHasher>::default().hash_one(hint) == hash)
+}
+
 fn hints(
     hints: &mut Vec<InlayHint>,
     famous_defs @ FamousDefs(sema, _): &FamousDefs<'_, '_>,

src/tools/rust-analyzer/crates/ide/src/inlay_hints/adjustment.rs

@@ -147,7 +147,6 @@ pub(super) fn hints(
             None,
         );
         acc.push(InlayHint {
-            needs_resolve: label.needs_resolve(),
             range: expr.syntax().text_range(),
             pad_left: false,
             pad_right: false,

src/tools/rust-analyzer/crates/ide/src/inlay_hints/bind_pat.rs

@@ -99,7 +99,6 @@ pub(super) fn hints(
         None => pat.syntax().text_range(),
     };
     acc.push(InlayHint {
-        needs_resolve: label.needs_resolve() || text_edit.is_some(),
         range: match type_ascriptable {
             Some(Some(t)) => text_range.cover(t.text_range()),
             _ => text_range,
@@ -177,11 +176,7 @@ mod tests {
     use syntax::{TextRange, TextSize};
     use test_utils::extract_annotations;
 
-    use crate::{
+    use crate::{fixture, inlay_hints::InlayHintsConfig, ClosureReturnTypeHints};
-        fixture,
-        inlay_hints::{InlayHintsConfig, RangeLimit},
-        ClosureReturnTypeHints,
-    };
 
     use crate::inlay_hints::tests::{
         check, check_edit, check_no_edit, check_with_config, DISABLED_CONFIG, TEST_CONFIG,
@@ -404,7 +399,7 @@ fn main() {
             .inlay_hints(
                 &InlayHintsConfig { type_hints: true, ..DISABLED_CONFIG },
                 file_id,
-                Some(RangeLimit::Fixed(TextRange::new(TextSize::from(500), TextSize::from(600)))),
+                Some(TextRange::new(TextSize::from(500), TextSize::from(600))),
             )
             .unwrap();
         let actual =

src/tools/rust-analyzer/crates/ide/src/inlay_hints/binding_mode.rs

@@ -50,7 +50,6 @@ pub(super) fn hints(
             _ => return,
         };
         acc.push(InlayHint {
-            needs_resolve: false,
             range,
             kind: InlayKind::BindingMode,
             label: r.into(),
@@ -69,7 +68,6 @@ pub(super) fn hints(
                 hir::BindingMode::Ref(Mutability::Shared) => "ref",
             };
             acc.push(InlayHint {
-                needs_resolve: false,
                 range: pat.syntax().text_range(),
                 kind: InlayKind::BindingMode,
                 label: bm.into(),

src/tools/rust-analyzer/crates/ide/src/inlay_hints/chaining.rs

@@ -59,7 +59,6 @@ pub(super) fn hints(
             }
             let label = label_of_ty(famous_defs, config, &ty)?;
             acc.push(InlayHint {
-                needs_resolve: label.needs_resolve(),
                 range: expr.syntax().text_range(),
                 kind: InlayKind::Chaining,
                 label,

src/tools/rust-analyzer/crates/ide/src/inlay_hints/closing_brace.rs

@@ -109,7 +109,6 @@ pub(super) fn hints(
 
     let linked_location = name_range.map(|range| FileRange { file_id, range });
     acc.push(InlayHint {
-        needs_resolve: linked_location.is_some(),
         range: closing_token.text_range(),
         kind: InlayKind::ClosingBrace,
         label: InlayHintLabel::simple(label, None, linked_location),

src/tools/rust-analyzer/crates/ide/src/inlay_hints/closure_captures.rs

@@ -32,7 +32,6 @@ pub(super) fn hints(
             let range = closure.syntax().first_token()?.prev_token()?.text_range();
             let range = TextRange::new(range.end() - TextSize::from(1), range.end());
             acc.push(InlayHint {
-                needs_resolve: false,
                 range,
                 kind: InlayKind::ClosureCapture,
                 label: InlayHintLabel::from("move"),
@@ -45,7 +44,6 @@ pub(super) fn hints(
         }
     };
     acc.push(InlayHint {
-        needs_resolve: false,
         range: move_kw_range,
         kind: InlayKind::ClosureCapture,
         label: InlayHintLabel::from("("),
@@ -79,7 +77,6 @@ pub(super) fn hints(
             }),
         );
         acc.push(InlayHint {
-            needs_resolve: label.needs_resolve(),
             range: move_kw_range,
             kind: InlayKind::ClosureCapture,
             label,
@@ -91,7 +88,6 @@ pub(super) fn hints(
 
         if idx != last {
             acc.push(InlayHint {
-                needs_resolve: false,
                 range: move_kw_range,
                 kind: InlayKind::ClosureCapture,
                 label: InlayHintLabel::from(", "),
@@ -103,7 +99,6 @@ pub(super) fn hints(
         }
     }
     acc.push(InlayHint {
-        needs_resolve: false,
         range: move_kw_range,
         kind: InlayKind::ClosureCapture,
         label: InlayHintLabel::from(")"),