Auto merge of #139996 - matthiaskrgr:rollup-0nka2hw, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #138528 (deref patterns: implement implicit deref patterns)
 - #139393 (rustdoc-json: Output target feature information)
 - #139553 (sync::mpsc: prevent double free on `Drop`)
 - #139615 (Remove `name_or_empty`)
 - #139853 (Disable combining LLD with external llvm-config)
 - #139913 (rustdoc/clean: Fix lowering of fn params (fixes correctness & HIR vs. middle parity regressions))
 - #139942 (Ignore aix for tests/ui/erros/pic-linker.rs)

r? `@ghost`
`@rustbot` modify labels: rollup

tests/rustdoc-json/targets/aarch64_apple_darwin.rs

@@ -0,0 +1,14 @@
+//@ only-aarch64-apple-darwin
+
+//@ is "$.target.triple" \"aarch64-apple-darwin\"
+//@ is "$.target.target_features[?(@.name=='vh')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='sve')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='sve2')].implies_features" '["sve"]'
+//@ is "$.target.target_features[?(@.name=='sve2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='cssc')].unstable_feature_gate" '"aarch64_unstable_target_feature"'
+//@ is "$.target.target_features[?(@.name=='v9a')].unstable_feature_gate" '"aarch64_ver_target_feature"'
+
+// Ensure we don't look like x86-64
+//@ !has "$.target.target_features[?(@.name=='avx2')]"

tests/rustdoc-json/targets/aarch64_reflects_compiler_options.rs

@@ -0,0 +1,10 @@
+//@ only-aarch64
+
+// If we enable SVE Bit Permute, we should see that it is enabled
+//@ compile-flags: -Ctarget-feature=+sve2-bitperm
+//@ is "$.target.target_features[?(@.name=='sve2-bitperm')].globally_enabled" true
+
+// As well as its dependency chain
+//@ is "$.target.target_features[?(@.name=='sve2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='sve')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='neon')].globally_enabled" true

tests/rustdoc-json/targets/aarch64_unknown_linux_gnu.rs

@@ -0,0 +1,14 @@
+//@ only-aarch64-unknown-linux-gnu
+
+//@ is "$.target.triple" \"aarch64-unknown-linux-gnu\"
+//@ is "$.target.target_features[?(@.name=='neon')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='sve')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='sve2')].implies_features" '["sve"]'
+//@ is "$.target.target_features[?(@.name=='sve2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='cssc')].unstable_feature_gate" '"aarch64_unstable_target_feature"'
+//@ is "$.target.target_features[?(@.name=='v9a')].unstable_feature_gate" '"aarch64_ver_target_feature"'
+
+// Ensure we don't look like x86-64
+//@ !has "$.target.target_features[?(@.name=='avx2')]"

tests/rustdoc-json/targets/i686_pc_windows_msvc.rs

@@ -0,0 +1,14 @@
+//@ only-i686-pc-windows-msvc
+
+//@ is "$.target.triple" \"i686-pc-windows-msvc\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc-json/targets/i686_unknown_linux_gnu.rs

@@ -0,0 +1,14 @@
+//@ only-i686-unknown-linux-gnu
+
+//@ is "$.target.triple" \"i686-unknown-linux-gnu\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc-json/targets/x86_64_apple_darwin.rs

@@ -0,0 +1,14 @@
+//@ only-x86_64-apple-darwin
+
+//@ is "$.target.triple" \"x86_64-apple-darwin\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc-json/targets/x86_64_pc_windows_gnu.rs

@@ -0,0 +1,14 @@
+//@ only-x86_64-pc-windows-gnu
+
+//@ is "$.target.triple" \"x86_64-pc-windows-gnu\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc-json/targets/x86_64_pc_windows_msvc.rs

@@ -0,0 +1,14 @@
+//@ only-x86_64-pc-windows-msvc
+
+//@ is "$.target.triple" \"x86_64-pc-windows-msvc\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc-json/targets/x86_64_reflects_compiler_options.rs

@@ -0,0 +1,10 @@
+//@ only-x86_64
+
+// If we enable AVX2, we should see that it is enabled
+//@ compile-flags: -Ctarget-feature=+avx2
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" true
+
+// As well as its dependency chain
+//@ is "$.target.target_features[?(@.name=='avx')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='sse4.2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='sse4.1')].globally_enabled" true

tests/rustdoc-json/targets/x86_64_unknown_linux_gnu.rs

@@ -0,0 +1,14 @@
+//@ only-x86_64-unknown-linux-gnu
+
+//@ is "$.target.triple" \"x86_64-unknown-linux-gnu\"
+//@ is "$.target.target_features[?(@.name=='sse2')].globally_enabled" true
+//@ is "$.target.target_features[?(@.name=='avx2')].globally_enabled" false
+//@ has "$.target.target_features[?(@.name=='avx2')].implies_features" '["avx"]'
+//@ is "$.target.target_features[?(@.name=='avx2')].unstable_feature_gate" null
+
+// If this breaks due to stabilization, check rustc_target::target_features for a replacement
+//@ is "$.target.target_features[?(@.name=='amx-tile')].unstable_feature_gate" '"x86_amx_intrinsics"'
+//@ is "$.target.target_features[?(@.name=='x87')].unstable_feature_gate" '"x87_target_feature"'
+
+// Ensure we don't look like aarch64
+//@ !has "$.target.target_features[?(@.name=='sve2')]"

tests/rustdoc/anon-fn-params.rs

@@ -0,0 +1,25 @@
+// Test that we render the deprecated anonymous trait function parameters from Rust 2015 as
+// underscores in order not to perpetuate it and for legibility.
+
+//@ edition: 2015
+#![expect(anonymous_parameters)]
+
+// Check the "local case" (HIR cleaning) //
+
+//@ has anon_fn_params/trait.Trait.html
+pub trait Trait {
+    //@ has - '//*[@id="tymethod.required"]' 'fn required(_: Option<i32>, _: impl Fn(&str) -> bool)'
+    fn required(Option<i32>, impl Fn(&str) -> bool);
+    //@ has - '//*[@id="method.provided"]' 'fn provided(_: [i32; 2])'
+    fn provided([i32; 2]) {}
+}
+
+// Check the "extern case" (middle cleaning) //
+
+//@ aux-build: ext-anon-fn-params.rs
+extern crate ext_anon_fn_params;
+
+//@ has anon_fn_params/trait.ExtTrait.html
+//@ has - '//*[@id="tymethod.required"]' 'fn required(_: Option<i32>, _: impl Fn(&str) -> bool)'
+//@ has - '//*[@id="method.provided"]' 'fn provided(_: [i32; 2])'
+pub use ext_anon_fn_params::Trait as ExtTrait;

tests/rustdoc/assoc-fns.rs

@@ -0,0 +1,13 @@
+// Basic testing for associated functions (in traits, trait impls & inherent impls).
+
+//@ has assoc_fns/trait.Trait.html
+pub trait Trait {
+    //@ has - '//*[@id="tymethod.required"]' 'fn required(first: i32, second: &str)'
+    fn required(first: i32, second: &str);
+
+    //@ has - '//*[@id="method.provided"]' 'fn provided(only: ())'
+    fn provided(only: ()) {}
+
+    //@ has - '//*[@id="tymethod.params_are_unnamed"]' 'fn params_are_unnamed(_: i32, _: u32)'
+    fn params_are_unnamed(_: i32, _: u32);
+}

tests/rustdoc/auxiliary/ext-anon-fn-params.rs

@@ -0,0 +1,7 @@
+//@ edition: 2015
+#![expect(anonymous_parameters)]
+
+pub trait Trait {
+    fn required(Option<i32>, impl Fn(&str) -> bool);
+    fn provided([i32; 2]) {}
+}

tests/rustdoc/ffi.rs

@@ -9,4 +9,8 @@ pub use lib::foreigner;
 extern "C" {
     //@ has ffi/fn.another.html //pre 'pub unsafe extern "C" fn another(cold_as_ice: u32)'
     pub fn another(cold_as_ice: u32);
+
+    //@ has ffi/fn.params_are_unnamed.html //pre \
+    //      'pub unsafe extern "C" fn params_are_unnamed(_: i32, _: u32)'
+    pub fn params_are_unnamed(_: i32, _: u32);
 }

tests/rustdoc/inline_cross/default-generic-args.rs

@@ -53,17 +53,17 @@ pub use default_generic_args::R2;
 
 //@ has user/type.H0.html
 // Check that we handle higher-ranked regions correctly:
-//@ has - '//*[@class="rust item-decl"]//code' "fn(_: for<'a> fn(_: Re<'a>))"
+//@ has - '//*[@class="rust item-decl"]//code' "fn(for<'a> fn(Re<'a>))"
 pub use default_generic_args::H0;
 
 //@ has user/type.H1.html
 // Check that we don't conflate distinct universially quantified regions (#1):
-//@ has - '//*[@class="rust item-decl"]//code' "for<'b> fn(_: for<'a> fn(_: Re<'a, &'b ()>))"
+//@ has - '//*[@class="rust item-decl"]//code' "for<'b> fn(for<'a> fn(Re<'a, &'b ()>))"
 pub use default_generic_args::H1;
 
 //@ has user/type.H2.html
 // Check that we don't conflate distinct universially quantified regions (#2):
-//@ has - '//*[@class="rust item-decl"]//code' "for<'a> fn(_: for<'b> fn(_: Re<'a, &'b ()>))"
+//@ has - '//*[@class="rust item-decl"]//code' "for<'a> fn(for<'b> fn(Re<'a, &'b ()>))"
 pub use default_generic_args::H2;
 
 //@ has user/type.P0.html
@@ -86,7 +86,7 @@ pub use default_generic_args::A0;
 // Demonstrates that we currently don't elide generic arguments that are alpha-equivalent to their
 // respective generic parameter (after instantiation) for perf reasons (it would require us to
 // create an inference context).
-//@ has - '//*[@class="rust item-decl"]//code' "Alpha<for<'arbitrary> fn(_: &'arbitrary ())>"
+//@ has - '//*[@class="rust item-decl"]//code' "Alpha<for<'arbitrary> fn(&'arbitrary ())>"
 pub use default_generic_args::A1;
 
 //@ has user/type.M0.html

tests/rustdoc/inline_cross/fn-ptr-ty.rs

@@ -2,11 +2,11 @@
 // They should be rendered exactly as the user wrote it, i.e., in source order and with unused
 // parameters present, not stripped.
 
-//@ aux-crate:fn_type=fn-type.rs
+//@ aux-crate:fn_ptr_ty=fn-ptr-ty.rs
 //@ edition: 2021
 #![crate_name = "user"]
 
 //@ has user/type.F.html
 //@ has - '//*[@class="rust item-decl"]//code' \
-//     "for<'z, 'a, '_unused> fn(_: &'z for<'b> fn(_: &'b str), _: &'a ()) -> &'a ();"
-pub use fn_type::F;
+//     "for<'z, 'a, '_unused> fn(&'z for<'b> fn(&'b str), &'a ()) -> &'a ();"
+pub use fn_ptr_ty::F;

tests/rustdoc/inline_cross/impl_trait.rs

@@ -29,7 +29,7 @@ pub use impl_trait_aux::func4;
 //@ has impl_trait/fn.func5.html
 //@ has - '//pre[@class="rust item-decl"]' "func5("
 //@ has - '//pre[@class="rust item-decl"]' "_f: impl for<'any> Fn(&'any str, &'any str) -> bool + for<'r> Other<T<'r> = ()>,"
-//@ has - '//pre[@class="rust item-decl"]' "_a: impl for<'beta, 'alpha, '_gamma> Auxiliary<'alpha, Item<'beta> = fn(_: &'beta ())>"
+//@ has - '//pre[@class="rust item-decl"]' "_a: impl for<'beta, 'alpha, '_gamma> Auxiliary<'alpha, Item<'beta> = fn(&'beta ())>"
 //@ !has - '//pre[@class="rust item-decl"]' 'where'
 pub use impl_trait_aux::func5;
 

tests/ui/abi/debug.rs

@@ -52,3 +52,6 @@ type TestAbiNeSign = (fn(i32), fn(u32)); //~ ERROR: ABIs are not compatible
 
 #[rustc_abi(assert_eq)]
 type TestAbiEqNonsense = (fn((str, str)), fn((str, str))); //~ ERROR: cannot be known at compilation time
+
+#[rustc_abi("assert_eq")] //~ ERROR unrecognized argument
+type Bad = u32;

tests/ui/abi/debug.stderr

@@ -906,6 +906,12 @@ LL | type TestAbiEqNonsense = (fn((str, str)), fn((str, str)));
    = help: the trait `Sized` is not implemented for `str`
    = note: only the last element of a tuple may have a dynamically sized type
 
+error: unrecognized argument
+  --> $DIR/debug.rs:56:13
+   |
+LL | #[rustc_abi("assert_eq")]
+   |             ^^^^^^^^^^^
+
 error: `#[rustc_abi]` can only be applied to function items, type aliases, and associated functions
   --> $DIR/debug.rs:29:5
    |
@@ -1004,6 +1010,6 @@ error: fn_abi_of(assoc_test) = FnAbi {
 LL |     fn assoc_test(&self) { }
    |     ^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 11 previous errors
+error: aborting due to 12 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/attributes/check-builtin-attr-ice.rs

@@ -39,13 +39,17 @@
 
 // Notably, `should_panic` is a `AttributeType::Normal` attribute that is checked separately.
 
+#![deny(unused_attributes)]
+
 struct Foo {
     #[should_panic::skip]
     //~^ ERROR failed to resolve
+    //~| ERROR `#[should_panic::skip]` only has an effect on functions
     pub field: u8,
 
     #[should_panic::a::b::c]
     //~^ ERROR failed to resolve
+    //~| ERROR `#[should_panic::a::b::c]` only has an effect on functions
     pub field2: u8,
 }
 

tests/ui/attributes/check-builtin-attr-ice.stderr

@@ -1,21 +1,39 @@
 error[E0433]: failed to resolve: use of unresolved module or unlinked crate `should_panic`
-  --> $DIR/check-builtin-attr-ice.rs:43:7
+  --> $DIR/check-builtin-attr-ice.rs:45:7
    |
 LL |     #[should_panic::skip]
    |       ^^^^^^^^^^^^ use of unresolved module or unlinked crate `should_panic`
 
 error[E0433]: failed to resolve: use of unresolved module or unlinked crate `should_panic`
-  --> $DIR/check-builtin-attr-ice.rs:47:7
+  --> $DIR/check-builtin-attr-ice.rs:50:7
    |
 LL |     #[should_panic::a::b::c]
    |       ^^^^^^^^^^^^ use of unresolved module or unlinked crate `should_panic`
 
 error[E0433]: failed to resolve: use of unresolved module or unlinked crate `deny`
-  --> $DIR/check-builtin-attr-ice.rs:55:7
+  --> $DIR/check-builtin-attr-ice.rs:59:7
    |
 LL |     #[deny::skip]
    |       ^^^^ use of unresolved module or unlinked crate `deny`
 
-error: aborting due to 3 previous errors
+error: `#[should_panic::skip]` only has an effect on functions
+  --> $DIR/check-builtin-attr-ice.rs:45:5
+   |
+LL |     #[should_panic::skip]
+   |     ^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/check-builtin-attr-ice.rs:42:9
+   |
+LL | #![deny(unused_attributes)]
+   |         ^^^^^^^^^^^^^^^^^
+
+error: `#[should_panic::a::b::c]` only has an effect on functions
+  --> $DIR/check-builtin-attr-ice.rs:50:5
+   |
+LL |     #[should_panic::a::b::c]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0433`.

tests/ui/attributes/invalid_macro_export_argument.deny.stderr

@@ -10,11 +10,17 @@ note: the lint level is defined here
 LL | #![cfg_attr(deny, deny(invalid_macro_export_arguments))]
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: `not_local_inner_macros` isn't a valid `#[macro_export]` argument
+error: invalid `#[macro_export]` argument
   --> $DIR/invalid_macro_export_argument.rs:13:16
    |
 LL | #[macro_export(not_local_inner_macros)]
    |                ^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: invalid `#[macro_export]` argument
+  --> $DIR/invalid_macro_export_argument.rs:33:16
+   |
+LL | #[macro_export("blah")]
+   |                ^^^^^^
+
+error: aborting due to 3 previous errors
 

tests/ui/attributes/invalid_macro_export_argument.rs

@@ -11,7 +11,7 @@ macro_rules! a {
 }
 
 #[macro_export(not_local_inner_macros)]
-//[deny]~^ ERROR `not_local_inner_macros` isn't a valid `#[macro_export]` argument
+//[deny]~^ ERROR invalid `#[macro_export]` argument
 macro_rules! b {
     () => ()
 }
@@ -30,4 +30,10 @@ macro_rules! e {
     () => ()
 }
 
+#[macro_export("blah")]
+//[deny]~^ ERROR invalid `#[macro_export]` argument
+macro_rules! f {
+    () => ()
+}
+
 fn main() {}

tests/ui/attributes/no-sanitize.rs

@@ -38,3 +38,8 @@ fn valid() {}
 
 #[no_sanitize(address)]
 static VALID : i32 = 0;
+
+#[no_sanitize("address")]
+//~^ ERROR `#[no_sanitize(...)]` should be applied to a function
+//~| ERROR invalid argument for `no_sanitize`
+static VALID2 : i32 = 0;

tests/ui/attributes/no-sanitize.stderr

@@ -59,5 +59,22 @@ LL | #[no_sanitize(address, memory)]
 LL | static INVALID : i32 = 0;
    | ------------------------- not a function
 
-error: aborting due to 7 previous errors
+error: `#[no_sanitize(...)]` should be applied to a function
+  --> $DIR/no-sanitize.rs:42:15
+   |
+LL | #[no_sanitize("address")]
+   |               ^^^^^^^^^
+...
+LL | static VALID2 : i32 = 0;
+   | ------------------------ not a function
+
+error: invalid argument for `no_sanitize`
+  --> $DIR/no-sanitize.rs:42:15
+   |
+LL | #[no_sanitize("address")]
+   |               ^^^^^^^^^
+   |
+   = note: expected one of: `address`, `cfi`, `hwaddress`, `kcfi`, `memory`, `memtag`, `shadow-call-stack`, or `thread`
+
+error: aborting due to 9 previous errors
 

tests/ui/errors/pic-linker.rs

@@ -5,6 +5,7 @@
 //@ ignore-windows
 //@ ignore-macos
 //@ ignore-cross-compile
+//@ ignore-aix
 
 //@ compile-flags: -Clink-args=-Wl,-z,text
 //@ run-pass

tests/ui/pattern/deref-patterns/bindings.rs

@@ -1,7 +1,9 @@
+//@ revisions: explicit implicit
 //@ run-pass
 #![feature(deref_patterns)]
 #![allow(incomplete_features)]
 
+#[cfg(explicit)]
 fn simple_vec(vec: Vec<u32>) -> u32 {
     match vec {
         deref!([]) => 100,
@@ -13,6 +15,19 @@ fn simple_vec(vec: Vec<u32>) -> u32 {
     }
 }
 
+#[cfg(implicit)]
+fn simple_vec(vec: Vec<u32>) -> u32 {
+    match vec {
+        [] => 100,
+        [x] if x == 4 => x + 4,
+        [x] => x,
+        [1, x] => x + 200,
+        deref!(ref slice) => slice.iter().sum(),
+        _ => 2000,
+    }
+}
+
+#[cfg(explicit)]
 fn nested_vec(vecvec: Vec<Vec<u32>>) -> u32 {
     match vecvec {
         deref!([]) => 0,
@@ -24,6 +39,19 @@ fn nested_vec(vecvec: Vec<Vec<u32>>) -> u32 {
     }
 }
 
+#[cfg(implicit)]
+fn nested_vec(vecvec: Vec<Vec<u32>>) -> u32 {
+    match vecvec {
+        [] => 0,
+        [[x]] => x,
+        [[0, x] | [1, x]] => x,
+        [ref x] => x.iter().sum(),
+        [[], [1, x, y]] => y - x,
+        _ => 2000,
+    }
+}
+
+#[cfg(explicit)]
 fn ref_mut(val: u32) -> u32 {
     let mut b = Box::new(0u32);
     match &mut b {
@@ -37,6 +65,21 @@ fn ref_mut(val: u32) -> u32 {
     *x
 }
 
+#[cfg(implicit)]
+fn ref_mut(val: u32) -> u32 {
+    let mut b = Box::new((0u32,));
+    match &mut b {
+        (_x,) if false => unreachable!(),
+        (x,) => {
+            *x = val;
+        }
+        _ => unreachable!(),
+    }
+    let (x,) = &b else { unreachable!() };
+    *x
+}
+
+#[cfg(explicit)]
 #[rustfmt::skip]
 fn or_and_guard(tuple: (u32, u32)) -> u32 {
     let mut sum = 0;
@@ -48,6 +91,18 @@ fn or_and_guard(tuple: (u32, u32)) -> u32 {
     sum
 }
 
+#[cfg(implicit)]
+#[rustfmt::skip]
+fn or_and_guard(tuple: (u32, u32)) -> u32 {
+    let mut sum = 0;
+    let b = Box::new(tuple);
+    match b {
+        (x, _) | (_, x) if { sum += x; false } => {},
+        _ => {},
+    }
+    sum
+}
+
 fn main() {
     assert_eq!(simple_vec(vec![1]), 1);
     assert_eq!(simple_vec(vec![1, 2]), 202);

tests/ui/pattern/deref-patterns/branch.rs

@@ -1,8 +1,10 @@
+//@ revisions: explicit implicit
 //@ run-pass
 // Test the execution of deref patterns.
 #![feature(deref_patterns)]
 #![allow(incomplete_features)]
 
+#[cfg(explicit)]
 fn branch(vec: Vec<u32>) -> u32 {
     match vec {
         deref!([]) => 0,
@@ -12,6 +14,17 @@ fn branch(vec: Vec<u32>) -> u32 {
     }
 }
 
+#[cfg(implicit)]
+fn branch(vec: Vec<u32>) -> u32 {
+    match vec {
+        [] => 0,
+        [1, _, 3] => 1,
+        [2, ..] => 2,
+        _ => 1000,
+    }
+}
+
+#[cfg(explicit)]
 fn nested(vec: Vec<Vec<u32>>) -> u32 {
     match vec {
         deref!([deref!([]), ..]) => 1,
@@ -20,6 +33,15 @@ fn nested(vec: Vec<Vec<u32>>) -> u32 {
     }
 }
 
+#[cfg(implicit)]
+fn nested(vec: Vec<Vec<u32>>) -> u32 {
+    match vec {
+        [[], ..] => 1,
+        [[0, ..], [1, ..]] => 2,
+        _ => 1000,
+    }
+}
+
 fn main() {
     assert!(matches!(Vec::<u32>::new(), deref!([])));
     assert!(matches!(vec![1], deref!([1])));

tests/ui/pattern/deref-patterns/cant_move_out_of_pattern.rs

@@ -21,4 +21,22 @@ fn cant_move_out_rc(rc: Rc<Struct>) -> Struct {
     }
 }
 
+struct Container(Struct);
+
+fn cant_move_out_box_implicit(b: Box<Container>) -> Struct {
+    match b {
+        //~^ ERROR: cannot move out of a shared reference
+        Container(x) => x,
+        _ => unreachable!(),
+    }
+}
+
+fn cant_move_out_rc_implicit(rc: Rc<Container>) -> Struct {
+    match rc {
+        //~^ ERROR: cannot move out of a shared reference
+        Container(x) => x,
+        _ => unreachable!(),
+    }
+}
+
 fn main() {}

tests/ui/pattern/deref-patterns/cant_move_out_of_pattern.stderr

@@ -32,6 +32,40 @@ help: consider borrowing the pattern binding
 LL |         deref!(ref x) => x,
    |                +++
 
-error: aborting due to 2 previous errors
+error[E0507]: cannot move out of a shared reference
+  --> $DIR/cant_move_out_of_pattern.rs:27:11
+   |
+LL |     match b {
+   |           ^
+LL |
+LL |         Container(x) => x,
+   |                   -
+   |                   |
+   |                   data moved here
+   |                   move occurs because `x` has type `Struct`, which does not implement the `Copy` trait
+   |
+help: consider borrowing the pattern binding
+   |
+LL |         Container(ref x) => x,
+   |                   +++
+
+error[E0507]: cannot move out of a shared reference
+  --> $DIR/cant_move_out_of_pattern.rs:35:11
+   |
+LL |     match rc {
+   |           ^^
+LL |
+LL |         Container(x) => x,
+   |                   -
+   |                   |
+   |                   data moved here
+   |                   move occurs because `x` has type `Struct`, which does not implement the `Copy` trait
+   |
+help: consider borrowing the pattern binding
+   |
+LL |         Container(ref x) => x,
+   |                   +++
+
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0507`.

tests/ui/pattern/deref-patterns/closure_capture.rs

@@ -11,6 +11,15 @@ fn main() {
     assert_eq!(b.len(), 3);
     f();
 
+    let v = vec![1, 2, 3];
+    let f = || {
+        // this should count as a borrow of `v` as a whole
+        let [.., x] = v else { unreachable!() };
+        assert_eq!(x, 3);
+    };
+    assert_eq!(v, [1, 2, 3]);
+    f();
+
     let mut b = Box::new("aaa".to_string());
     let mut f = || {
         let deref!(ref mut s) = b else { unreachable!() };
@@ -18,4 +27,22 @@ fn main() {
     };
     f();
     assert_eq!(b.len(), 5);
+
+    let mut v = vec![1, 2, 3];
+    let mut f = || {
+        // this should count as a mutable borrow of `v` as a whole
+        let [.., ref mut x] = v else { unreachable!() };
+        *x = 4;
+    };
+    f();
+    assert_eq!(v, [1, 2, 4]);
+
+    let mut v = vec![1, 2, 3];
+    let mut f = || {
+        // here, `[.., x]` is adjusted by both an overloaded deref and a builtin deref
+        let [.., x] = &mut v else { unreachable!() };
+        *x = 4;
+    };
+    f();
+    assert_eq!(v, [1, 2, 4]);
 }

tests/ui/pattern/deref-patterns/fake_borrows.rs

@@ -11,4 +11,11 @@ fn main() {
         deref!(false) => {}
         _ => {},
     }
+    match b {
+        true => {}
+        _ if { *b = true; false } => {}
+        //~^ ERROR cannot assign `*b` in match guard
+        false => {}
+        _ => {},
+    }
 }

tests/ui/pattern/deref-patterns/fake_borrows.stderr

@@ -7,6 +7,15 @@ LL |         deref!(true) => {}
 LL |         _ if { *b = true; false } => {}
    |                ^^^^^^^^^ cannot assign
 
-error: aborting due to 1 previous error
+error[E0510]: cannot assign `*b` in match guard
+  --> $DIR/fake_borrows.rs:16:16
+   |
+LL |     match b {
+   |           - value is immutable in match guard
+LL |         true => {}
+LL |         _ if { *b = true; false } => {}
+   |                ^^^^^^^^^ cannot assign
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0510`.

tests/ui/pattern/deref-patterns/implicit-const-deref.rs

@@ -0,0 +1,19 @@
+//! Test that we get an error about structural equality rather than a type error when attempting to
+//! use const patterns of library pointer types. Currently there aren't any smart pointers that can
+//! be used in constant patterns, but we still need to make sure we don't implicitly dereference the
+//! scrutinee and end up with a type error; this would prevent us from reporting that only constants
+//! supporting structural equality can be used as patterns.
+#![feature(deref_patterns)]
+#![allow(incomplete_features)]
+
+const EMPTY: Vec<()> = Vec::new();
+
+fn main() {
+    // FIXME(inline_const_pat): if `inline_const_pat` is reinstated, there should be a case here for
+    // inline const block patterns as well; they're checked differently than named constants.
+    match vec![()] {
+        EMPTY => {}
+        //~^ ERROR: constant of non-structural type `Vec<()>` in a pattern
+        _ => {}
+    }
+}

tests/ui/pattern/deref-patterns/implicit-const-deref.stderr

@@ -0,0 +1,16 @@
+error: constant of non-structural type `Vec<()>` in a pattern
+  --> $DIR/implicit-const-deref.rs:15:9
+   |
+LL | const EMPTY: Vec<()> = Vec::new();
+   | -------------------- constant defined here
+...
+LL |         EMPTY => {}
+   |         ^^^^^ constant of non-structural type
+  --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
+   |
+   = note: `Vec<()>` must be annotated with `#[derive(PartialEq)]` to be usable in patterns
+   |
+   = note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details
+
+error: aborting due to 1 previous error
+

tests/ui/pattern/deref-patterns/implicit-cow-deref.rs

@@ -0,0 +1,45 @@
+//@ run-pass
+//! Test that implicit deref patterns interact as expected with `Cow` constructor patterns.
+#![feature(deref_patterns)]
+#![allow(incomplete_features)]
+
+use std::borrow::Cow;
+
+fn main() {
+    let cow: Cow<'static, [u8]> = Cow::Borrowed(&[1, 2, 3]);
+
+    match cow {
+        [..] => {}
+        _ => unreachable!(),
+    }
+
+    match cow {
+        Cow::Borrowed(_) => {}
+        Cow::Owned(_) => unreachable!(),
+    }
+
+    match Box::new(&cow) {
+        Cow::Borrowed { 0: _ } => {}
+        Cow::Owned { 0: _ } => unreachable!(),
+        _ => unreachable!(),
+    }
+
+    let cow_of_cow: Cow<'_, Cow<'static, [u8]>> = Cow::Owned(cow);
+
+    match cow_of_cow {
+        [..] => {}
+        _ => unreachable!(),
+    }
+
+    // This matches on the outer `Cow` (the owned one).
+    match cow_of_cow {
+        Cow::Borrowed(_) => unreachable!(),
+        Cow::Owned(_) => {}
+    }
+
+    match Box::new(&cow_of_cow) {
+        Cow::Borrowed { 0: _ } => unreachable!(),
+        Cow::Owned { 0: _ } => {}
+        _ => unreachable!(),
+    }
+}

tests/ui/pattern/deref-patterns/needs-gate.rs

@@ -0,0 +1,15 @@
+// gate-test-deref_patterns
+
+fn main() {
+    match Box::new(0) {
+        deref!(0) => {}
+        //~^ ERROR: use of unstable library feature `deref_patterns`: placeholder syntax for deref patterns
+        _ => {}
+    }
+
+    match Box::new(0) {
+        0 => {}
+        //~^ ERROR: mismatched types
+        _ => {}
+    }
+}

tests/ui/pattern/deref-patterns/needs-gate.stderr

@@ -0,0 +1,29 @@
+error[E0658]: use of unstable library feature `deref_patterns`: placeholder syntax for deref patterns
+  --> $DIR/needs-gate.rs:5:9
+   |
+LL |         deref!(0) => {}
+   |         ^^^^^
+   |
+   = note: see issue #87121 <https://github.com/rust-lang/rust/issues/87121> for more information
+   = help: add `#![feature(deref_patterns)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0308]: mismatched types
+  --> $DIR/needs-gate.rs:11:9
+   |
+LL |     match Box::new(0) {
+   |           ----------- this expression has type `Box<{integer}>`
+LL |         0 => {}
+   |         ^ expected `Box<{integer}>`, found integer
+   |
+   = note: expected struct `Box<{integer}>`
+                found type `{integer}`
+help: consider dereferencing to access the inner value using the Deref trait
+   |
+LL |     match *Box::new(0) {
+   |           +
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0308, E0658.
+For more information about an error, try `rustc --explain E0308`.

tests/ui/pattern/deref-patterns/recursion-limit.rs

@@ -0,0 +1,23 @@
+//! Test that implicit deref patterns respect the recursion limit
+#![feature(deref_patterns)]
+#![allow(incomplete_features)]
+#![recursion_limit = "8"]
+
+use std::ops::Deref;
+
+struct Cyclic;
+impl Deref for Cyclic {
+    type Target = Cyclic;
+    fn deref(&self) -> &Cyclic {
+        &Cyclic
+    }
+}
+
+fn main() {
+    match &Box::new(Cyclic) {
+        () => {}
+        //~^ ERROR: reached the recursion limit while auto-dereferencing `Cyclic`
+        //~| ERROR: the trait bound `Cyclic: DerefPure` is not satisfied
+        _ => {}
+    }
+}

tests/ui/pattern/deref-patterns/recursion-limit.stderr

@@ -0,0 +1,18 @@
+error[E0055]: reached the recursion limit while auto-dereferencing `Cyclic`
+  --> $DIR/recursion-limit.rs:18:9
+   |
+LL |         () => {}
+   |         ^^ deref recursion limit reached
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "16"]` attribute to your crate (`recursion_limit`)
+
+error[E0277]: the trait bound `Cyclic: DerefPure` is not satisfied
+  --> $DIR/recursion-limit.rs:18:9
+   |
+LL |         () => {}
+   |         ^^ the trait `DerefPure` is not implemented for `Cyclic`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0055, E0277.
+For more information about an error, try `rustc --explain E0055`.

tests/ui/pattern/deref-patterns/ref-mut.rs

@@ -8,10 +8,19 @@ fn main() {
         deref!(x) => {}
         _ => {}
     }
+    match &mut vec![1] {
+        [x] => {}
+        _ => {}
+    }
 
     match &mut Rc::new(1) {
         deref!(x) => {}
         //~^ ERROR the trait bound `Rc<{integer}>: DerefMut` is not satisfied
         _ => {}
     }
+    match &mut Rc::new((1,)) {
+        (x,) => {}
+        //~^ ERROR the trait bound `Rc<({integer},)>: DerefMut` is not satisfied
+        _ => {}
+    }
 }

tests/ui/pattern/deref-patterns/ref-mut.stderr

@@ -8,13 +8,19 @@ LL | #![feature(deref_patterns)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0277]: the trait bound `Rc<{integer}>: DerefMut` is not satisfied
-  --> $DIR/ref-mut.rs:13:9
+  --> $DIR/ref-mut.rs:17:9
    |
 LL |         deref!(x) => {}
    |         ^^^^^^^^^ the trait `DerefMut` is not implemented for `Rc<{integer}>`
    |
    = note: this error originates in the macro `deref` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 1 previous error; 1 warning emitted
+error[E0277]: the trait bound `Rc<({integer},)>: DerefMut` is not satisfied
+  --> $DIR/ref-mut.rs:22:9
+   |
+LL |         (x,) => {}
+   |         ^^^^ the trait `DerefMut` is not implemented for `Rc<({integer},)>`
+
+error: aborting due to 2 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/pattern/deref-patterns/typeck.rs

@@ -10,26 +10,32 @@ fn main() {
     let vec: Vec<u32> = Vec::new();
     match vec {
         deref!([..]) => {}
+        [..] => {}
         _ => {}
     }
     match Box::new(true) {
         deref!(true) => {}
+        true => {}
         _ => {}
     }
     match &Box::new(true) {
         deref!(true) => {}
+        true => {}
         _ => {}
     }
     match &Rc::new(0) {
         deref!(1..) => {}
+        1.. => {}
         _ => {}
     }
     let _: &Struct = match &Rc::new(Struct) {
         deref!(x) => x,
+        Struct => &Struct,
         _ => unreachable!(),
     };
     let _: &[Struct] = match &Rc::new(vec![Struct]) {
         deref!(deref!(x)) => x,
+        [Struct] => &[Struct],
         _ => unreachable!(),
     };
 }

tests/ui/pattern/deref-patterns/typeck_fail.rs

@@ -7,11 +7,22 @@ fn main() {
     match "foo".to_string() {
         deref!("foo") => {}
         //~^ ERROR: mismatched types
+        "foo" => {}
+        //~^ ERROR: mismatched types
         _ => {}
     }
     match &"foo".to_string() {
         deref!("foo") => {}
         //~^ ERROR: mismatched types
+        "foo" => {}
+        //~^ ERROR: mismatched types
+        _ => {}
+    }
+
+    // Make sure we don't try implicitly dereferncing any ADT.
+    match Some(0) {
+        Ok(0) => {}
+        //~^ ERROR: mismatched types
         _ => {}
     }
 }

tests/ui/pattern/deref-patterns/typeck_fail.stderr

@@ -7,13 +7,45 @@ LL |         deref!("foo") => {}
    |                ^^^^^ expected `str`, found `&str`
 
 error[E0308]: mismatched types
-  --> $DIR/typeck_fail.rs:13:16
+  --> $DIR/typeck_fail.rs:10:9
+   |
+LL |     match "foo".to_string() {
+   |           ----------------- this expression has type `String`
+...
+LL |         "foo" => {}
+   |         ^^^^^ expected `String`, found `&str`
+
+error[E0308]: mismatched types
+  --> $DIR/typeck_fail.rs:15:16
    |
 LL |     match &"foo".to_string() {
    |           ------------------ this expression has type `&String`
 LL |         deref!("foo") => {}
    |                ^^^^^ expected `str`, found `&str`
 
-error: aborting due to 2 previous errors
+error[E0308]: mismatched types
+  --> $DIR/typeck_fail.rs:17:9
+   |
+LL |     match &"foo".to_string() {
+   |           ------------------ this expression has type `&String`
+...
+LL |         "foo" => {}
+   |         ^^^^^ expected `&String`, found `&str`
+   |
+   = note: expected reference `&String`
+              found reference `&'static str`
+
+error[E0308]: mismatched types
+  --> $DIR/typeck_fail.rs:24:9
+   |
+LL |     match Some(0) {
+   |           ------- this expression has type `Option<{integer}>`
+LL |         Ok(0) => {}
+   |         ^^^^^ expected `Option<{integer}>`, found `Result<_, _>`
+   |
+   = note: expected enum `Option<{integer}>`
+              found enum `Result<_, _>`
+
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0308`.

tests/ui/pattern/deref-patterns/unsatisfied-bounds.rs

@@ -0,0 +1,21 @@
+#![feature(deref_patterns)]
+#![allow(incomplete_features)]
+
+struct MyPointer;
+
+impl std::ops::Deref for MyPointer {
+    type Target = ();
+    fn deref(&self) -> &() {
+        &()
+    }
+}
+
+fn main() {
+    // Test that we get a trait error if a user attempts implicit deref pats on their own impls.
+    // FIXME(deref_patterns): there should be a special diagnostic for missing `DerefPure`.
+    match MyPointer {
+        () => {}
+        //~^ the trait bound `MyPointer: DerefPure` is not satisfied
+        _ => {}
+    }
+}

tests/ui/pattern/deref-patterns/unsatisfied-bounds.stderr

@@ -0,0 +1,9 @@
+error[E0277]: the trait bound `MyPointer: DerefPure` is not satisfied
+  --> $DIR/unsatisfied-bounds.rs:17:9
+   |
+LL |         () => {}
+   |         ^^ the trait `DerefPure` is not implemented for `MyPointer`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.