Auto merge of #47748 - alexcrichton:rollup, r=alexcrichton

Rollup of 19 pull requests

- Successful merges: #47415, #47437, #47439, #47453, #47460, #47502, #47529, #47600, #47607, #47618, #47626, #47656, #47668, #47696, #47701, #47705, #47710, #47711, #47719
- Failed merges: #47455, #47521

src/bootstrap/bin/rustc.rs

@@ -125,11 +125,6 @@ fn main() {
             cmd.arg(format!("-Clinker={}", target_linker));
         }
 
-        // Pass down incremental directory, if any.
-        if let Ok(dir) = env::var("RUSTC_INCREMENTAL") {
-            cmd.arg(format!("-Zincremental={}", dir));
-        }
-
         let crate_name = args.windows(2)
             .find(|a| &*a[0] == "--crate-name")
             .unwrap();

src/bootstrap/bootstrap.py

@@ -602,6 +602,7 @@ class RustBuild(object):
         env["LIBRARY_PATH"] = os.path.join(self.bin_root(), "lib") + \
             (os.pathsep + env["LIBRARY_PATH"]) \
             if "LIBRARY_PATH" in env else ""
+        env["RUSTFLAGS"] = "-Cdebuginfo=2"
         env["PATH"] = os.path.join(self.bin_root(), "bin") + \
             os.pathsep + env["PATH"]
         if not os.path.isfile(self.cargo()):

src/bootstrap/builder.rs

@@ -26,6 +26,7 @@ use util::{exe, libdir, add_lib_path};
 use {Build, Mode};
 use cache::{INTERNER, Interned, Cache};
 use check;
+use test;
 use flags::Subcommand;
 use doc;
 use tool;
@@ -230,6 +231,7 @@ impl<'a> ShouldRun<'a> {
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum Kind {
     Build,
+    Check,
     Test,
     Bench,
     Dist,
@@ -251,13 +253,13 @@ impl<'a> Builder<'a> {
                 tool::Compiletest, tool::RemoteTestServer, tool::RemoteTestClient,
                 tool::RustInstaller, tool::Cargo, tool::Rls, tool::Rustdoc, tool::Clippy,
                 native::Llvm, tool::Rustfmt, tool::Miri),
-            Kind::Test => describe!(check::Tidy, check::Bootstrap, check::DefaultCompiletest,
+            Kind::Check => describe!(check::Std, check::Test, check::Rustc),
-                check::HostCompiletest, check::Crate, check::CrateLibrustc, check::Rustdoc,
+            Kind::Test => describe!(test::Tidy, test::Bootstrap, test::DefaultCompiletest,
-                check::Linkcheck, check::Cargotest, check::Cargo, check::Rls, check::Docs,
+                test::HostCompiletest, test::Crate, test::CrateLibrustc, test::Rustdoc,
-                check::ErrorIndex, check::Distcheck, check::Rustfmt, check::Miri, check::Clippy,
+                test::Linkcheck, test::Cargotest, test::Cargo, test::Rls, test::Docs,
-                check::RustdocJS),
+                test::ErrorIndex, test::Distcheck, test::Rustfmt, test::Miri, test::Clippy,
-
+                test::RustdocJS),
-            Kind::Bench => describe!(check::Crate, check::CrateLibrustc),
+            Kind::Bench => describe!(test::Crate, test::CrateLibrustc),
             Kind::Doc => describe!(doc::UnstableBook, doc::UnstableBookGen, doc::TheBook,
                 doc::Standalone, doc::Std, doc::Test, doc::Rustc, doc::ErrorIndex, doc::Nomicon,
                 doc::Reference, doc::Rustdoc, doc::RustByExample, doc::CargoBook),
@@ -304,6 +306,7 @@ impl<'a> Builder<'a> {
     pub fn run(build: &Build) {
         let (kind, paths) = match build.config.cmd {
             Subcommand::Build { ref paths } => (Kind::Build, &paths[..]),
+            Subcommand::Check { ref paths } => (Kind::Check, &paths[..]),
             Subcommand::Doc { ref paths } => (Kind::Doc, &paths[..]),
             Subcommand::Test { ref paths, .. } => (Kind::Test, &paths[..]),
             Subcommand::Bench { ref paths, .. } => (Kind::Bench, &paths[..]),
@@ -493,13 +496,14 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_CODEGEN_UNITS", n.to_string());
         }
 
+
         if let Some(host_linker) = self.build.linker(compiler.host) {
             cargo.env("RUSTC_HOST_LINKER", host_linker);
         }
         if let Some(target_linker) = self.build.linker(target) {
             cargo.env("RUSTC_TARGET_LINKER", target_linker);
         }
-        if cmd != "build" {
+        if cmd != "build" && cmd != "check" {
             cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(self.compiler(2, self.build.build)));
         }
 
@@ -566,8 +570,7 @@ impl<'a> Builder<'a> {
         // not guaranteeing correctness across builds if the compiler
         // is changing under your feet.`
         if self.config.incremental && compiler.stage == 0 {
-            let incr_dir = self.incremental_dir(compiler);
+            cargo.env("CARGO_INCREMENTAL", "1");
-            cargo.env("RUSTC_INCREMENTAL", incr_dir);
         }
 
         if let Some(ref on_fail) = self.config.on_fail {

src/bootstrap/compile.rs

@@ -108,7 +108,8 @@ impl Step for Std {
         std_cargo(build, &compiler, target, &mut cargo);
         run_cargo(build,
                   &mut cargo,
-                  &libstd_stamp(build, compiler, target));
+                  &libstd_stamp(build, compiler, target),
+                  false);
 
         builder.ensure(StdLink {
             compiler: builder.compiler(compiler.stage, build.build),
@@ -360,7 +361,8 @@ impl Step for Test {
         test_cargo(build, &compiler, target, &mut cargo);
         run_cargo(build,
                   &mut cargo,
-                  &libtest_stamp(build, compiler, target));
+                  &libtest_stamp(build, compiler, target),
+                  false);
 
         builder.ensure(TestLink {
             compiler: builder.compiler(compiler.stage, build.build),
@@ -488,7 +490,8 @@ impl Step for Rustc {
         rustc_cargo(build, target, &mut cargo);
         run_cargo(build,
                   &mut cargo,
-                  &librustc_stamp(build, compiler, target));
+                  &librustc_stamp(build, compiler, target),
+                  false);
 
         builder.ensure(RustcLink {
             compiler: builder.compiler(compiler.stage, build.build),
@@ -755,7 +758,7 @@ impl Step for Assemble {
 ///
 /// For a particular stage this will link the file listed in `stamp` into the
 /// `sysroot_dst` provided.
-fn add_to_sysroot(sysroot_dst: &Path, stamp: &Path) {
+pub fn add_to_sysroot(sysroot_dst: &Path, stamp: &Path) {
     t!(fs::create_dir_all(&sysroot_dst));
     for path in read_stamp_file(stamp) {
         copy(&path, &sysroot_dst.join(path.file_name().unwrap()));
@@ -785,7 +788,7 @@ fn stderr_isatty() -> bool {
     }
 }
 
-fn run_cargo(build: &Build, cargo: &mut Command, stamp: &Path) {
+pub fn run_cargo(build: &Build, cargo: &mut Command, stamp: &Path, is_check: bool) {
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.
     cargo.arg("--message-format").arg("json")
@@ -836,7 +839,8 @@ fn run_cargo(build: &Build, cargo: &mut Command, stamp: &Path) {
             // Skip files like executables
             if !filename.ends_with(".rlib") &&
                !filename.ends_with(".lib") &&
-               !is_dylib(&filename) {
+               !is_dylib(&filename) &&
+               !(is_check && filename.ends_with(".rmeta")) {
                 continue
             }
 

src/bootstrap/flags.rs

@@ -48,6 +48,9 @@ pub enum Subcommand {
     Build {
         paths: Vec<PathBuf>,
     },
+    Check {
+        paths: Vec<PathBuf>,
+    },
     Doc {
         paths: Vec<PathBuf>,
     },
@@ -88,6 +91,7 @@ Usage: x.py <subcommand> [options] [<paths>...]
 
 Subcommands:
     build       Compile either the compiler or libraries
+    check       Compile either the compiler or libraries, using cargo check
     test        Build and run some test suites
     bench       Build and run some benchmarks
     doc         Build documentation
@@ -128,6 +132,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`");
         // there on out.
         let subcommand = args.iter().find(|&s|
             (s == "build")
+            || (s == "check")
             || (s == "test")
             || (s == "bench")
             || (s == "doc")
@@ -217,6 +222,21 @@ Arguments:
     arguments would), and then use the compiler built in stage 0 to build
     src/libtest and its dependencies.
     Once this is done, build/$ARCH/stage1 contains a usable compiler.");
+            }
+            "check" => {
+                subcommand_help.push_str("\n
+Arguments:
+    This subcommand accepts a number of paths to directories to the crates
+    and/or artifacts to compile. For example:
+
+        ./x.py check src/libcore
+        ./x.py check src/libcore src/libproc_macro
+
+    If no arguments are passed then the complete artifacts are compiled: std, test, and rustc. Note
+    also that since we use `cargo check`, by default this will automatically enable incremental
+    compilation, so there's no need to pass it separately, though it won't hurt. We also completely
+    ignore the stage passed, as there's no way to compile in non-stage 0 without actually building
+    the compiler.");
             }
             "test" => {
                 subcommand_help.push_str("\n
@@ -286,6 +306,9 @@ Arguments:
             "build" => {
                 Subcommand::Build { paths: paths }
             }
+            "check" => {
+                Subcommand::Check { paths: paths }
+            }
             "test" => {
                 Subcommand::Test {
                     paths,

src/bootstrap/lib.rs

@@ -150,6 +150,7 @@ use util::{exe, libdir, OutputFolder, CiEnv};
 mod cc_detect;
 mod channel;
 mod check;
+mod test;
 mod clean;
 mod compile;
 mod metadata;
@@ -449,12 +450,6 @@ impl Build {
         out
     }
 
-    /// Get the directory for incremental by-products when using the
-    /// given compiler.
-    fn incremental_dir(&self, compiler: Compiler) -> PathBuf {
-        self.out.join(&*compiler.host).join(format!("stage{}-incremental", compiler.stage))
-    }
-
     /// Returns the root directory for all output generated in a particular
     /// stage when running with a particular host compiler.
     ///
@@ -776,7 +771,11 @@ impl Build {
     fn release(&self, num: &str) -> String {
         match &self.config.channel[..] {
             "stable" => num.to_string(),
-            "beta" => format!("{}-beta.{}", num, self.beta_prerelease_version()),
+            "beta" => if self.rust_info.is_git() {
+                format!("{}-beta.{}", num, self.beta_prerelease_version())
+            } else {
+                format!("{}-beta", num)
+            },
             "nightly" => format!("{}-nightly", num),
             _ => format!("{}-dev", num),
         }

src/ci/docker/dist-x86_64-freebsd/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
   clang \

src/libcompiler_builtins

@@ -1 +1 @@
-Subproject commit 0ba07e49264a54cb5bbd4856fcea083bb3fbec15
+Subproject commit 0a95675bab808c49f86208bacc89c5d9c53ac43f

src/librustc/dep_graph/dep_node.rs

@@ -638,6 +638,7 @@ define_dep_nodes!( <'tcx>
     [input] TargetFeaturesWhitelist,
     [] TargetFeaturesEnabled(DefId),
 
+    [] InstanceDefSizeEstimate { instance_def: InstanceDef<'tcx> },
 );
 
 trait DepNodeParams<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> : fmt::Debug {

src/librustc/hir/intravisit.rs

@@ -43,7 +43,6 @@
 
 use syntax::abi::Abi;
 use syntax::ast::{NodeId, CRATE_NODE_ID, Name, Attribute};
-use syntax::codemap::Spanned;
 use syntax_pos::Span;
 use hir::*;
 use hir::def::Def;
@@ -336,6 +335,9 @@ pub trait Visitor<'v> : Sized {
     fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) {
         walk_variant(self, v, g, item_id)
     }
+    fn visit_label(&mut self, label: &'v Label) {
+        walk_label(self, label)
+    }
     fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
         walk_lifetime(self, lifetime)
     }
@@ -370,18 +372,6 @@ pub trait Visitor<'v> : Sized {
     }
 }
 
-pub fn walk_opt_name<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
-    if let Some(name) = opt_name {
-        visitor.visit_name(span, name);
-    }
-}
-
-pub fn walk_opt_sp_name<'v, V: Visitor<'v>>(visitor: &mut V, opt_sp_name: &Option<Spanned<Name>>) {
-    if let Some(ref sp_name) = *opt_sp_name {
-        visitor.visit_name(sp_name.span, sp_name.node);
-    }
-}
-
 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
     visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
@@ -420,6 +410,10 @@ pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
     walk_list!(visitor, visit_ty, &local.ty);
 }
 
+pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
+    visitor.visit_name(label.span, label.name);
+}
+
 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
     visitor.visit_id(lifetime.id);
     match lifetime.name {
@@ -452,7 +446,9 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
     match item.node {
         ItemExternCrate(opt_name) => {
             visitor.visit_id(item.id);
-            walk_opt_name(visitor, item.span, opt_name)
+            if let Some(name) = opt_name {
+                visitor.visit_name(item.span, name);
+            }
         }
         ItemUse(ref path, _) => {
             visitor.visit_id(item.id);
@@ -993,14 +989,14 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             visitor.visit_expr(if_block);
             walk_list!(visitor, visit_expr, optional_else);
         }
-        ExprWhile(ref subexpression, ref block, ref opt_sp_name) => {
+        ExprWhile(ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_name(visitor, opt_sp_name);
         }
-        ExprLoop(ref block, ref opt_sp_name, _) => {
+        ExprLoop(ref block, ref opt_label, _) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_block(block);
-            walk_opt_sp_name(visitor, opt_sp_name);
         }
         ExprMatch(ref subexpression, ref arms, _) => {
             visitor.visit_expr(subexpression);
@@ -1036,28 +1032,28 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
         ExprPath(ref qpath) => {
             visitor.visit_qpath(qpath, expression.id, expression.span);
         }
-        ExprBreak(label, ref opt_expr) => {
+        ExprBreak(ref destination, ref opt_expr) => {
-            label.ident.map(|ident| {
+            if let Some(ref label) = destination.label {
-                match label.target_id {
+                visitor.visit_label(label);
+                match destination.target_id {
                     ScopeTarget::Block(node_id) |
                     ScopeTarget::Loop(LoopIdResult::Ok(node_id)) =>
                         visitor.visit_def_mention(Def::Label(node_id)),
                     ScopeTarget::Loop(LoopIdResult::Err(_)) => {},
                 };
-                visitor.visit_name(ident.span, ident.node.name);
+            }
-            });
             walk_list!(visitor, visit_expr, opt_expr);
         }
-        ExprAgain(label) => {
+        ExprAgain(ref destination) => {
-            label.ident.map(|ident| {
+            if let Some(ref label) = destination.label {
-                match label.target_id {
+                visitor.visit_label(label);
+                match destination.target_id {
                     ScopeTarget::Block(_) => bug!("can't `continue` to a non-loop block"),
                     ScopeTarget::Loop(LoopIdResult::Ok(node_id)) =>
                         visitor.visit_def_mention(Def::Label(node_id)),
                     ScopeTarget::Loop(LoopIdResult::Err(_)) => {},
                 };
-                visitor.visit_name(ident.span, ident.node.name);
+            }
-            });
         }
         ExprRet(ref optional_expression) => {
             walk_list!(visitor, visit_expr, optional_expression);

src/librustc/hir/lowering.rs

@@ -773,22 +773,22 @@ impl<'a> LoweringContext<'a> {
         *self.name_map.entry(ident).or_insert_with(|| Symbol::from_ident(ident))
     }
 
-    fn lower_opt_sp_ident(&mut self, o_id: Option<Spanned<Ident>>) -> Option<Spanned<Name>> {
+    fn lower_label(&mut self, label: Option<Label>) -> Option<hir::Label> {
-        o_id.map(|sp_ident| respan(sp_ident.span, sp_ident.node.name))
+        label.map(|label| hir::Label { name: label.ident.name, span: label.span })
     }
 
-    fn lower_loop_destination(&mut self, destination: Option<(NodeId, Spanned<Ident>)>)
+    fn lower_loop_destination(&mut self, destination: Option<(NodeId, Label)>)
         -> hir::Destination
     {
         match destination {
-            Some((id, label_ident)) => {
+            Some((id, label)) => {
                 let target = if let Def::Label(loop_id) = self.expect_full_def(id) {
                     hir::LoopIdResult::Ok(self.lower_node_id(loop_id).node_id)
                 } else {
                     hir::LoopIdResult::Err(hir::LoopIdError::UnresolvedLabel)
                 };
                 hir::Destination {
-                    ident: Some(label_ident),
+                    label: self.lower_label(Some(label)),
                     target_id: hir::ScopeTarget::Loop(target),
                 }
             },
@@ -798,7 +798,7 @@ impl<'a> LoweringContext<'a> {
                                   .map(|innermost_loop_id| *innermost_loop_id);
 
                 hir::Destination {
-                    ident: None,
+                    label: None,
                     target_id: hir::ScopeTarget::Loop(
                         loop_id.map(|id| Ok(self.lower_node_id(id).node_id))
                                .unwrap_or(Err(hir::LoopIdError::OutsideLoopScope))
@@ -2751,17 +2751,17 @@ impl<'a> LoweringContext<'a> {
 
                 hir::ExprIf(P(self.lower_expr(cond)), P(then_expr), else_opt)
             }
-            ExprKind::While(ref cond, ref body, opt_ident) => {
+            ExprKind::While(ref cond, ref body, opt_label) => {
                 self.with_loop_scope(e.id, |this|
                     hir::ExprWhile(
                         this.with_loop_condition_scope(|this| P(this.lower_expr(cond))),
                         this.lower_block(body, false),
-                        this.lower_opt_sp_ident(opt_ident)))
+                        this.lower_label(opt_label)))
             }
-            ExprKind::Loop(ref body, opt_ident) => {
+            ExprKind::Loop(ref body, opt_label) => {
                 self.with_loop_scope(e.id, |this|
                     hir::ExprLoop(this.lower_block(body, false),
-                                  this.lower_opt_sp_ident(opt_ident),
+                                  this.lower_label(opt_label),
                                   hir::LoopSource::Loop))
             }
             ExprKind::Catch(ref body) => {
@@ -2837,8 +2837,8 @@ impl<'a> LoweringContext<'a> {
                     (&None, &Some(..), Closed) => "RangeToInclusive",
                     (&Some(..), &Some(..), Closed) => "RangeInclusive",
                     (_, &None, Closed) =>
-                        panic!(self.diagnostic().span_fatal(
+                        self.diagnostic().span_fatal(
-                            e.span, "inclusive range with no end")),
+                            e.span, "inclusive range with no end").raise(),
                 };
 
                 let fields =
@@ -2877,30 +2877,30 @@ impl<'a> LoweringContext<'a> {
                 hir::ExprPath(self.lower_qpath(e.id, qself, path, ParamMode::Optional,
                                                ImplTraitContext::Disallowed))
             }
-            ExprKind::Break(opt_ident, ref opt_expr) => {
+            ExprKind::Break(opt_label, ref opt_expr) => {
-                let label_result = if self.is_in_loop_condition && opt_ident.is_none() {
+                let destination = if self.is_in_loop_condition && opt_label.is_none() {
                     hir::Destination {
-                        ident: opt_ident,
+                        label: None,
                         target_id: hir::ScopeTarget::Loop(
                                 Err(hir::LoopIdError::UnlabeledCfInWhileCondition).into()),
                     }
                 } else {
-                    self.lower_loop_destination(opt_ident.map(|ident| (e.id, ident)))
+                    self.lower_loop_destination(opt_label.map(|label| (e.id, label)))
                 };
                 hir::ExprBreak(
-                        label_result,
+                        destination,
                         opt_expr.as_ref().map(|x| P(self.lower_expr(x))))
             }
-            ExprKind::Continue(opt_ident) =>
+            ExprKind::Continue(opt_label) =>
                 hir::ExprAgain(
-                    if self.is_in_loop_condition && opt_ident.is_none() {
+                    if self.is_in_loop_condition && opt_label.is_none() {
                         hir::Destination {
-                            ident: opt_ident,
+                            label: None,
                             target_id: hir::ScopeTarget::Loop(Err(
                                 hir::LoopIdError::UnlabeledCfInWhileCondition).into()),
                         }
                     } else {
-                        self.lower_loop_destination(opt_ident.map( |ident| (e.id, ident)))
+                        self.lower_loop_destination(opt_label.map(|label| (e.id, label)))
                     }),
             ExprKind::Ret(ref e) => hir::ExprRet(e.as_ref().map(|x| P(self.lower_expr(x)))),
             ExprKind::InlineAsm(ref asm) => {
@@ -3000,7 +3000,7 @@ impl<'a> LoweringContext<'a> {
 
             // Desugar ExprWhileLet
             // From: `[opt_ident]: while let <pat> = <sub_expr> <body>`
-            ExprKind::WhileLet(ref pat, ref sub_expr, ref body, opt_ident) => {
+            ExprKind::WhileLet(ref pat, ref sub_expr, ref body, opt_label) => {
                 // to:
                 //
                 //   [opt_ident]: loop {
@@ -3041,7 +3041,7 @@ impl<'a> LoweringContext<'a> {
 
                 // `[opt_ident]: loop { ... }`
                 let loop_block = P(self.block_expr(P(match_expr)));
-                let loop_expr = hir::ExprLoop(loop_block, self.lower_opt_sp_ident(opt_ident),
+                let loop_expr = hir::ExprLoop(loop_block, self.lower_label(opt_label),
                                               hir::LoopSource::WhileLet);
                 // add attributes to the outer returned expr node
                 loop_expr
@@ -3049,7 +3049,7 @@ impl<'a> LoweringContext<'a> {
 
             // Desugar ExprForLoop
             // From: `[opt_ident]: for <pat> in <head> <body>`
-            ExprKind::ForLoop(ref pat, ref head, ref body, opt_ident) => {
+            ExprKind::ForLoop(ref pat, ref head, ref body, opt_label) => {
                 // to:
                 //
                 //   {
@@ -3150,7 +3150,7 @@ impl<'a> LoweringContext<'a> {
                                                   None));
 
                 // `[opt_ident]: loop { ... }`
-                let loop_expr = hir::ExprLoop(loop_block, self.lower_opt_sp_ident(opt_ident),
+                let loop_expr = hir::ExprLoop(loop_block, self.lower_label(opt_label),
                                               hir::LoopSource::ForLoop);
                 let LoweredNodeId { node_id, hir_id } = self.lower_node_id(e.id);
                 let loop_expr = P(hir::Expr {
@@ -3270,7 +3270,7 @@ impl<'a> LoweringContext<'a> {
                             e.span,
                             hir::ExprBreak(
                                 hir::Destination {
-                                    ident: None,
+                                    label: None,
                                     target_id: hir::ScopeTarget::Block(catch_node),
                                 },
                                 Some(from_err_expr)

src/librustc/hir/mod.rs

@@ -34,7 +34,7 @@ use util::nodemap::{NodeMap, FxHashSet};
 use syntax_pos::{Span, DUMMY_SP};
 use syntax::codemap::{self, Spanned};
 use syntax::abi::Abi;
-use syntax::ast::{self, Ident, Name, NodeId, DUMMY_NODE_ID, AsmDialect};
+use syntax::ast::{self, Name, NodeId, DUMMY_NODE_ID, AsmDialect};
 use syntax::ast::{Attribute, Lit, StrStyle, FloatTy, IntTy, UintTy, MetaItem};
 use syntax::ext::hygiene::SyntaxContext;
 use syntax::ptr::P;
@@ -172,6 +172,18 @@ pub const DUMMY_HIR_ID: HirId = HirId {
 
 pub const DUMMY_ITEM_LOCAL_ID: ItemLocalId = ItemLocalId(!0);
 
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
+pub struct Label {
+    pub name: Name,
+    pub span: Span,
+}
+
+impl fmt::Debug for Label {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "label({:?})", self.name)
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
@@ -1276,11 +1288,11 @@ pub enum Expr_ {
     /// A while loop, with an optional label
     ///
     /// `'label: while expr { block }`
-    ExprWhile(P<Expr>, P<Block>, Option<Spanned<Name>>),
+    ExprWhile(P<Expr>, P<Block>, Option<Label>),
     /// Conditionless loop (can be exited with break, continue, or return)
     ///
     /// `'label: loop { block }`
-    ExprLoop(P<Block>, Option<Spanned<Name>>, LoopSource),
+    ExprLoop(P<Block>, Option<Label>, LoopSource),
     /// A `match` block, with a source that indicates whether or not it is
     /// the result of a desugaring, and if so, which kind.
     ExprMatch(P<Expr>, HirVec<Arm>, MatchSource),
@@ -1459,7 +1471,7 @@ impl ScopeTarget {
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub struct Destination {
     // This is `Some(_)` iff there is an explicit user-specified `label
-    pub ident: Option<Spanned<Ident>>,
+    pub label: Option<Label>,
 
     // These errors are caught and then reported during the diagnostics pass in
     // librustc_passes/loops.rs

src/librustc/hir/print.rs

@@ -1337,9 +1337,9 @@ impl<'a> State<'a> {
             hir::ExprIf(ref test, ref blk, ref elseopt) => {
                 self.print_if(&test, &blk, elseopt.as_ref().map(|e| &**e))?;
             }
-            hir::ExprWhile(ref test, ref blk, opt_sp_name) => {
+            hir::ExprWhile(ref test, ref blk, opt_label) => {
-                if let Some(sp_name) = opt_sp_name {
+                if let Some(label) = opt_label {
-                    self.print_name(sp_name.node)?;
+                    self.print_name(label.name)?;
                     self.word_space(":")?;
                 }
                 self.head("while")?;
@@ -1347,9 +1347,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block(&blk)?;
             }
-            hir::ExprLoop(ref blk, opt_sp_name, _) => {
+            hir::ExprLoop(ref blk, opt_label, _) => {
-                if let Some(sp_name) = opt_sp_name {
+                if let Some(label) = opt_label {
-                    self.print_name(sp_name.node)?;
+                    self.print_name(label.name)?;
                     self.word_space(":")?;
                 }
                 self.head("loop")?;
@@ -1424,11 +1424,11 @@ impl<'a> State<'a> {
             hir::ExprPath(ref qpath) => {
                 self.print_qpath(qpath, true)?
             }
-            hir::ExprBreak(label, ref opt_expr) => {
+            hir::ExprBreak(destination, ref opt_expr) => {
                 self.s.word("break")?;
                 self.s.space()?;
-                if let Some(label_ident) = label.ident {
+                if let Some(label) = destination.label {
-                    self.print_name(label_ident.node.name)?;
+                    self.print_name(label.name)?;
                     self.s.space()?;
                 }
                 if let Some(ref expr) = *opt_expr {
@@ -1436,11 +1436,11 @@ impl<'a> State<'a> {
                     self.s.space()?;
                 }
             }
-            hir::ExprAgain(label) => {
+            hir::ExprAgain(destination) => {
                 self.s.word("continue")?;
                 self.s.space()?;
-                if let Some(label_ident) = label.ident {
+                if let Some(label) = destination.label {
-                    self.print_name(label_ident.node.name)?;
+                    self.print_name(label.name)?;
                     self.s.space()?
                 }
             }

src/librustc/ich/impls_hir.rs

@@ -148,6 +148,11 @@ impl_stable_hash_for!(enum hir::LifetimeName {
     Name(name)
 });
 
+impl_stable_hash_for!(struct hir::Label {
+    span,
+    name
+});
+
 impl_stable_hash_for!(struct hir::Lifetime {
     id,
     span,
@@ -619,7 +624,7 @@ impl_stable_hash_for!(enum hir::CaptureClause {
 impl_stable_hash_for_spanned!(usize);
 
 impl_stable_hash_for!(struct hir::Destination {
-    ident,
+    label,
     target_id
 });
 

src/librustc/infer/region_constraints/mod.rs

@@ -82,7 +82,7 @@ pub type VarOrigins = IndexVec<RegionVid, RegionVariableOrigin>;
 /// Describes constraints between the region variables and other
 /// regions, as well as other conditions that must be verified, or
 /// assumptions that can be made.
-#[derive(Default)]
+#[derive(Debug, Default)]
 pub struct RegionConstraintData<'tcx> {
     /// Constraints of the form `A <= B`, where either `A` or `B` can
     /// be a region variable (or neither, as it happens).

src/librustc/middle/resolve_lifetime.rs

@@ -1018,7 +1018,7 @@ fn extract_labels(ctxt: &mut LifetimeContext<'_, '_>, body: &hir::Body) {
     fn expression_label(ex: &hir::Expr) -> Option<(ast::Name, Span)> {
         match ex.node {
             hir::ExprWhile(.., Some(label)) | hir::ExprLoop(_, Some(label), _) => {
-                Some((label.node, label.span))
+                Some((label.name, label.span))
             }
             _ => None,
         }

src/librustc/mir/mono.rs

@@ -10,7 +10,7 @@
 
 use syntax::ast::NodeId;
 use syntax::symbol::InternedString;
-use ty::Instance;
+use ty::{Instance, TyCtxt};
 use util::nodemap::FxHashMap;
 use rustc_data_structures::base_n;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasherResult,
@@ -25,6 +25,21 @@ pub enum MonoItem<'tcx> {
     GlobalAsm(NodeId),
 }
 
+impl<'tcx> MonoItem<'tcx> {
+    pub fn size_estimate<'a>(&self, tcx: &TyCtxt<'a, 'tcx, 'tcx>) -> usize {
+        match *self {
+            MonoItem::Fn(instance) => {
+                // Estimate the size of a function based on how many statements
+                // it contains.
+                tcx.instance_def_size_estimate(instance.def)
+            },
+            // Conservatively estimate the size of a static declaration
+            // or assembly to be 1.
+            MonoItem::Static(_) | MonoItem::GlobalAsm(_) => 1,
+        }
+    }
+}
+
 impl<'tcx> HashStable<StableHashingContext<'tcx>> for MonoItem<'tcx> {
     fn hash_stable<W: StableHasherResult>(&self,
                                            hcx: &mut StableHashingContext<'tcx>,
@@ -52,6 +67,7 @@ pub struct CodegenUnit<'tcx> {
     /// as well as the crate name and disambiguator.
     name: InternedString,
     items: FxHashMap<MonoItem<'tcx>, (Linkage, Visibility)>,
+    size_estimate: Option<usize>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
@@ -101,6 +117,7 @@ impl<'tcx> CodegenUnit<'tcx> {
         CodegenUnit {
             name: name,
             items: FxHashMap(),
+            size_estimate: None,
         }
     }
 
@@ -131,6 +148,24 @@ impl<'tcx> CodegenUnit<'tcx> {
         let hash = hash & ((1u128 << 80) - 1);
         base_n::encode(hash, base_n::CASE_INSENSITIVE)
     }
+
+    pub fn estimate_size<'a>(&mut self, tcx: &TyCtxt<'a, 'tcx, 'tcx>) {
+        // Estimate the size of a codegen unit as (approximately) the number of MIR
+        // statements it corresponds to.
+        self.size_estimate = Some(self.items.keys().map(|mi| mi.size_estimate(tcx)).sum());
+    }
+
+    pub fn size_estimate(&self) -> usize {
+        // Should only be called if `estimate_size` has previously been called.
+        self.size_estimate.expect("estimate_size must be called before getting a size_estimate")
+    }
+
+    pub fn modify_size_estimate(&mut self, delta: usize) {
+        assert!(self.size_estimate.is_some());
+        if let Some(size_estimate) = self.size_estimate {
+            self.size_estimate = Some(size_estimate + delta);
+        }
+    }
 }
 
 impl<'tcx> HashStable<StableHashingContext<'tcx>> for CodegenUnit<'tcx> {
@@ -140,6 +175,8 @@ impl<'tcx> HashStable<StableHashingContext<'tcx>> for CodegenUnit<'tcx> {
         let CodegenUnit {
             ref items,
             name,
+            // The size estimate is not relevant to the hash
+            size_estimate: _,
         } = *self;
 
         name.hash_stable(hcx, hasher);

src/librustc/session/config.rs

@@ -72,6 +72,26 @@ pub enum OptLevel {
     SizeMin, // -Oz
 }
 
+#[derive(Clone, Copy, PartialEq, Hash)]
+pub enum Lto {
+    /// Don't do any LTO whatsoever
+    No,
+
+    /// Do a full crate graph LTO. The flavor is determined by the compiler
+    /// (currently the default is "fat").
+    Yes,
+
+    /// Do a full crate graph LTO with ThinLTO
+    Thin,
+
+    /// Do a local graph LTO with ThinLTO (only relevant for multiple codegen
+    /// units).
+    ThinLocal,
+
+    /// Do a full crate graph LTO with "fat" LTO
+    Fat,
+}
+
 #[derive(Clone, Copy, PartialEq, Hash)]
 pub enum DebugInfoLevel {
     NoDebugInfo,
@@ -389,7 +409,7 @@ top_level_options!(
         // commands like `--emit llvm-ir` which they're often incompatible with
         // if we otherwise use the defaults of rustc.
         cli_forced_codegen_units: Option<usize> [UNTRACKED],
-        cli_forced_thinlto: Option<bool> [UNTRACKED],
+        cli_forced_thinlto_off: bool [UNTRACKED],
     }
 );
 
@@ -590,7 +610,7 @@ pub fn basic_options() -> Options {
         debug_assertions: true,
         actually_rustdoc: false,
         cli_forced_codegen_units: None,
-        cli_forced_thinlto: None,
+        cli_forced_thinlto_off: false,
     }
 }
 
@@ -780,11 +800,13 @@ macro_rules! options {
             Some("crate=integer");
         pub const parse_unpretty: Option<&'static str> =
             Some("`string` or `string=string`");
+        pub const parse_lto: Option<&'static str> =
+            Some("one of `thin`, `fat`, or omitted");
     }
 
     #[allow(dead_code)]
     mod $mod_set {
-        use super::{$struct_name, Passes, SomePasses, AllPasses, Sanitizer};
+        use super::{$struct_name, Passes, SomePasses, AllPasses, Sanitizer, Lto};
         use rustc_back::{LinkerFlavor, PanicStrategy, RelroLevel};
         use std::path::PathBuf;
 
@@ -978,6 +1000,16 @@ macro_rules! options {
                 _ => false,
             }
         }
+
+        fn parse_lto(slot: &mut Lto, v: Option<&str>) -> bool {
+            *slot = match v {
+                None => Lto::Yes,
+                Some("thin") => Lto::Thin,
+                Some("fat") => Lto::Fat,
+                Some(_) => return false,
+            };
+            true
+        }
     }
 ) }
 
@@ -994,7 +1026,7 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
         "extra arguments to append to the linker invocation (space separated)"),
     link_dead_code: bool = (false, parse_bool, [UNTRACKED],
         "don't let linker strip dead code (turning it on can be used for code coverage)"),
-    lto: bool = (false, parse_bool, [TRACKED],
+    lto: Lto = (Lto::No, parse_lto, [TRACKED],
         "perform LLVM link-time optimizations"),
     target_cpu: Option<String> = (None, parse_opt_string, [TRACKED],
         "select target processor (rustc --print target-cpus for details)"),
@@ -1135,6 +1167,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "treat all errors that occur as bugs"),
     external_macro_backtrace: bool = (false, parse_bool, [UNTRACKED],
           "show macro backtraces even for non-local macros"),
+    teach: bool = (false, parse_bool, [TRACKED],
+          "show extended diagnostic help"),
     continue_parse_after_error: bool = (false, parse_bool, [TRACKED],
           "attempt to recover from parse errors (experimental)"),
     incremental: Option<String> = (None, parse_opt_string, [UNTRACKED],
@@ -1333,7 +1367,7 @@ pub fn build_target_config(opts: &Options, sp: &Handler) -> Config {
             sp.struct_fatal(&format!("Error loading target specification: {}", e))
                 .help("Use `--print target-list` for a list of built-in targets")
                 .emit();
-            panic!(FatalError);
+            FatalError.raise();
         }
     };
 
@@ -1341,8 +1375,8 @@ pub fn build_target_config(opts: &Options, sp: &Handler) -> Config {
         "16" => (ast::IntTy::I16, ast::UintTy::U16),
         "32" => (ast::IntTy::I32, ast::UintTy::U32),
         "64" => (ast::IntTy::I64, ast::UintTy::U64),
-        w    => panic!(sp.fatal(&format!("target specification was invalid: \
+        w    => sp.fatal(&format!("target specification was invalid: \
-                                          unrecognized target-pointer-width {}", w))),
+                                          unrecognized target-pointer-width {}", w)).raise(),
     };
 
     Config {
@@ -1632,8 +1666,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
     let mut debugging_opts = build_debugging_options(matches, error_format);
 
     if !debugging_opts.unstable_options && error_format == ErrorOutputType::Json(true) {
-        early_error(ErrorOutputType::Json(false),
+        early_error(ErrorOutputType::Json(false), "--error-format=pretty-json is unstable");
-                    "--error-format=pretty-json is unstable");
     }
 
     let mut output_types = BTreeMap::new();
@@ -1677,7 +1710,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
 
     let mut cg = build_codegen_options(matches, error_format);
     let mut codegen_units = cg.codegen_units;
-    let mut thinlto = None;
+    let mut disable_thinlto = false;
 
     // Issue #30063: if user requests llvm-related output to one
     // particular path, disable codegen-units.
@@ -1699,12 +1732,12 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
                     }
                     early_warn(error_format, "resetting to default -C codegen-units=1");
                     codegen_units = Some(1);
-                    thinlto = Some(false);
+                    disable_thinlto = true;
                 }
             }
             _ => {
                 codegen_units = Some(1);
-                thinlto = Some(false);
+                disable_thinlto = true;
             }
         }
     }
@@ -1734,7 +1767,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         (&None, &None) => None,
     }.map(|m| PathBuf::from(m));
 
-    if cg.lto && incremental.is_some() {
+    if cg.lto != Lto::No && incremental.is_some() {
         early_error(error_format, "can't perform LTO when compiling incrementally");
     }
 
@@ -1934,7 +1967,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         debug_assertions,
         actually_rustdoc: false,
         cli_forced_codegen_units: codegen_units,
-        cli_forced_thinlto: thinlto,
+        cli_forced_thinlto_off: disable_thinlto,
     },
     cfg)
 }
@@ -2052,7 +2085,7 @@ mod dep_tracking {
     use std::hash::Hash;
     use std::path::PathBuf;
     use std::collections::hash_map::DefaultHasher;
-    use super::{Passes, CrateType, OptLevel, DebugInfoLevel,
+    use super::{Passes, CrateType, OptLevel, DebugInfoLevel, Lto,
                 OutputTypes, Externs, ErrorOutputType, Sanitizer};
     use syntax::feature_gate::UnstableFeatures;
     use rustc_back::{PanicStrategy, RelroLevel};
@@ -2107,6 +2140,7 @@ mod dep_tracking {
     impl_dep_tracking_hash_via_hash!(RelroLevel);
     impl_dep_tracking_hash_via_hash!(Passes);
     impl_dep_tracking_hash_via_hash!(OptLevel);
+    impl_dep_tracking_hash_via_hash!(Lto);
     impl_dep_tracking_hash_via_hash!(DebugInfoLevel);
     impl_dep_tracking_hash_via_hash!(UnstableFeatures);
     impl_dep_tracking_hash_via_hash!(Externs);
@@ -2180,6 +2214,7 @@ mod tests {
     use lint;
     use middle::cstore;
     use session::config::{build_configuration, build_session_options_and_crate_config};
+    use session::config::Lto;
     use session::build_session;
     use std::collections::{BTreeMap, BTreeSet};
     use std::iter::FromIterator;
@@ -2656,7 +2691,7 @@ mod tests {
 
         // Make sure changing a [TRACKED] option changes the hash
         opts = reference.clone();
-        opts.cg.lto = true;
+        opts.cg.lto = Lto::Fat;
         assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());
 
         opts = reference.clone();

src/librustc/session/mod.rs

@@ -250,7 +250,7 @@ impl Session {
     }
 
     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
-        panic!(self.diagnostic().span_fatal(sp, msg))
+        self.diagnostic().span_fatal(sp, msg).raise()
     }
     pub fn span_fatal_with_code<S: Into<MultiSpan>>(
         &self,
@@ -258,10 +258,10 @@ impl Session {
         msg: &str,
         code: DiagnosticId,
     ) -> ! {
-        panic!(self.diagnostic().span_fatal_with_code(sp, msg, code))
+        self.diagnostic().span_fatal_with_code(sp, msg, code).raise()
     }
     pub fn fatal(&self, msg: &str) -> ! {
-        panic!(self.diagnostic().fatal(msg))
+        self.diagnostic().fatal(msg).raise()
     }
     pub fn span_err_or_warn<S: Into<MultiSpan>>(&self, is_warning: bool, sp: S, msg: &str) {
         if is_warning {
@@ -498,9 +498,65 @@ impl Session {
             self.use_mir()
     }
 
-    pub fn lto(&self) -> bool {
+    /// Calculates the flavor of LTO to use for this compilation.
-        self.opts.cg.lto || self.target.target.options.requires_lto
+    pub fn lto(&self) -> config::Lto {
+        // If our target has codegen requirements ignore the command line
+        if self.target.target.options.requires_lto {
+            return config::Lto::Fat
+        }
+
+        // If the user specified something, return that. If they only said `-C
+        // lto` and we've for whatever reason forced off ThinLTO via the CLI,
+        // then ensure we can't use a ThinLTO.
+        match self.opts.cg.lto {
+            config::Lto::No => {}
+            config::Lto::Yes if self.opts.cli_forced_thinlto_off => {
+                return config::Lto::Fat
+            }
+            other => return other,
+        }
+
+        // Ok at this point the target doesn't require anything and the user
+        // hasn't asked for anything. Our next decision is whether or not
+        // we enable "auto" ThinLTO where we use multiple codegen units and
+        // then do ThinLTO over those codegen units. The logic below will
+        // either return `No` or `ThinLocal`.
+
+        // If processing command line options determined that we're incompatible
+        // with ThinLTO (e.g. `-C lto --emit llvm-ir`) then return that option.
+        if self.opts.cli_forced_thinlto_off {
+            return config::Lto::No
+        }
+
+        // If `-Z thinlto` specified process that, but note that this is mostly
+        // a deprecated option now that `-C lto=thin` exists.
+        if let Some(enabled) = self.opts.debugging_opts.thinlto {
+            if enabled {
+                return config::Lto::ThinLocal
+            } else {
+                return config::Lto::No
+            }
+        }
+
+        // If there's only one codegen unit and LTO isn't enabled then there's
+        // no need for ThinLTO so just return false.
+        if self.codegen_units() == 1 {
+            return config::Lto::No
+        }
+
+        // Right now ThinLTO isn't compatible with incremental compilation.
+        if self.opts.incremental.is_some() {
+            return config::Lto::No
+        }
+
+        // Now we're in "defaults" territory. By default we enable ThinLTO for
+        // optimized compiles (anything greater than O0).
+        match self.opts.optimize {
+            config::OptLevel::No => config::Lto::No,
+            _ => config::Lto::ThinLocal,
+        }
     }
+
     /// Returns the panic strategy for this compile session. If the user explicitly selected one
     /// using '-C panic', use that, otherwise use the panic strategy defined by the target.
     pub fn panic_strategy(&self) -> PanicStrategy {
@@ -805,36 +861,8 @@ impl Session {
         16
     }
 
-    /// Returns whether ThinLTO is enabled for this compilation
+    pub fn teach(&self, code: &DiagnosticId) -> bool {
-    pub fn thinlto(&self) -> bool {
+        self.opts.debugging_opts.teach && !self.parse_sess.span_diagnostic.code_emitted(code)
-        // If processing command line options determined that we're incompatible
-        // with ThinLTO (e.g. `-C lto --emit llvm-ir`) then return that option.
-        if let Some(enabled) = self.opts.cli_forced_thinlto {
-            return enabled
-        }
-
-        // If explicitly specified, use that with the next highest priority
-        if let Some(enabled) = self.opts.debugging_opts.thinlto {
-            return enabled
-        }
-
-        // If there's only one codegen unit and LTO isn't enabled then there's
-        // no need for ThinLTO so just return false.
-        if self.codegen_units() == 1 && !self.lto() {
-            return false
-        }
-
-        // Right now ThinLTO isn't compatible with incremental compilation.
-        if self.opts.incremental.is_some() {
-            return false
-        }
-
-        // Now we're in "defaults" territory. By default we enable ThinLTO for
-        // optimized compiles (anything greater than O0).
-        match self.opts.optimize {
-            config::OptLevel::No => false,
-            _ => true,
-        }
     }
 }
 
@@ -919,7 +947,7 @@ pub fn build_session_(sopts: config::Options,
     let host = match Target::search(config::host_triple()) {
         Ok(t) => t,
         Err(e) => {
-            panic!(span_diagnostic.fatal(&format!("Error loading host specification: {}", e)));
+            span_diagnostic.fatal(&format!("Error loading host specification: {}", e)).raise();
         }
     };
     let target_cfg = config::build_target_config(&sopts, &span_diagnostic);
@@ -945,7 +973,7 @@ pub fn build_session_(sopts: config::Options,
     let working_dir = match env::current_dir() {
         Ok(dir) => dir,
         Err(e) => {
-            panic!(p_s.span_diagnostic.fatal(&format!("Current directory is invalid: {}", e)))
+            p_s.span_diagnostic.fatal(&format!("Current directory is invalid: {}", e)).raise()
         }
     };
     let working_dir = file_path_mapping.map_prefix(working_dir);
@@ -1076,7 +1104,7 @@ pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
     };
     let handler = errors::Handler::with_emitter(true, false, emitter);
     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
-    panic!(errors::FatalError);
+    errors::FatalError.raise();
 }
 
 pub fn early_warn(output: config::ErrorOutputType, msg: &str) {

src/librustc/traits/error_reporting.rs

@@ -794,48 +794,56 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     }
 
     fn get_fn_like_arguments(&self, node: hir::map::Node) -> (Span, Vec<ArgKind>) {
-        if let hir::map::NodeExpr(&hir::Expr {
+        match node {
-            node: hir::ExprClosure(_, ref _decl, id, span, _),
+            hir::map::NodeExpr(&hir::Expr {
-            ..
+                node: hir::ExprClosure(_, ref _decl, id, span, _),
-        }) = node {
+                ..
-            (self.tcx.sess.codemap().def_span(span), self.tcx.hir.body(id).arguments.iter()
+            }) => {
-                .map(|arg| {
+                (self.tcx.sess.codemap().def_span(span), self.tcx.hir.body(id).arguments.iter()
-                    if let hir::Pat {
+                    .map(|arg| {
-                        node: hir::PatKind::Tuple(args, _),
+                        if let hir::Pat {
-                        span,
+                            node: hir::PatKind::Tuple(args, _),
-                        ..
-                    } = arg.pat.clone().into_inner() {
-                        ArgKind::Tuple(
                             span,
-                            args.iter().map(|pat| {
+                            ..
-                                let snippet = self.tcx.sess.codemap()
+                        } = arg.pat.clone().into_inner() {
-                                    .span_to_snippet(pat.span).unwrap();
+                            ArgKind::Tuple(
-                                (snippet, "_".to_owned())
+                                span,
-                            }).collect::<Vec<_>>(),
+                                args.iter().map(|pat| {
-                        )
+                                    let snippet = self.tcx.sess.codemap()
-                    } else {
+                                        .span_to_snippet(pat.span).unwrap();
-                        let name = self.tcx.sess.codemap().span_to_snippet(arg.pat.span).unwrap();
+                                    (snippet, "_".to_owned())
-                        ArgKind::Arg(name, "_".to_owned())
+                                }).collect::<Vec<_>>(),
-                    }
+                            )
-                })
+                        } else {
-                .collect::<Vec<ArgKind>>())
+                            let name = self.tcx.sess.codemap()
-        } else if let hir::map::NodeItem(&hir::Item {
+                                .span_to_snippet(arg.pat.span).unwrap();
-            span,
+                            ArgKind::Arg(name, "_".to_owned())
-            node: hir::ItemFn(ref decl, ..),
+                        }
-            ..
+                    })
-        }) = node {
+                    .collect::<Vec<ArgKind>>())
-            (self.tcx.sess.codemap().def_span(span), decl.inputs.iter()
+            }
-                    .map(|arg| match arg.clone().into_inner().node {
+            hir::map::NodeItem(&hir::Item {
-                hir::TyTup(ref tys) => ArgKind::Tuple(
+                span,
-                    arg.span,
+                node: hir::ItemFn(ref decl, ..),
-                    tys.iter()
+                ..
-                        .map(|_| ("_".to_owned(), "_".to_owned()))
+            }) |
-                        .collect::<Vec<_>>(),
+            hir::map::NodeImplItem(&hir::ImplItem {
-                ),
+                span,
-                _ => ArgKind::Arg("_".to_owned(), "_".to_owned())
+                node: hir::ImplItemKind::Method(hir::MethodSig { ref decl, .. }, _),
-            }).collect::<Vec<ArgKind>>())
+                ..
-        } else {
+            }) => {
-            panic!("non-FnLike node found: {:?}", node);
+                (self.tcx.sess.codemap().def_span(span), decl.inputs.iter()
+                        .map(|arg| match arg.clone().into_inner().node {
+                    hir::TyTup(ref tys) => ArgKind::Tuple(
+                        arg.span,
+                        tys.iter()
+                            .map(|_| ("_".to_owned(), "_".to_owned()))
+                            .collect::<Vec<_>>(),
+                    ),
+                    _ => ArgKind::Arg("_".to_owned(), "_".to_owned())
+                }).collect::<Vec<ArgKind>>())
+            }
+            _ => panic!("non-FnLike node found: {:?}", node),
         }
     }
 

src/librustc/traits/project.rs

@@ -101,7 +101,7 @@ pub struct MismatchedProjectionTypes<'tcx> {
     pub err: ty::error::TypeError<'tcx>
 }
 
-#[derive(PartialEq, Eq, Debug)]
+#[derive(PartialEq, Eq, PartialOrd, Ord, Debug)]
 enum ProjectionTyCandidate<'tcx> {
     // from a where-clause in the env or object type
     ParamEnv(ty::PolyProjectionPredicate<'tcx>),
@@ -293,9 +293,23 @@ impl<'a, 'b, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for AssociatedTypeNormalizer<'a,
                     Reveal::UserFacing => ty,
 
                     Reveal::All => {
+                        let recursion_limit = self.tcx().sess.recursion_limit.get();
+                        if self.depth >= recursion_limit {
+                            let obligation = Obligation::with_depth(
+                                self.cause.clone(),
+                                recursion_limit,
+                                self.param_env,
+                                ty,
+                            );
+                            self.selcx.infcx().report_overflow_error(&obligation, true);
+                        }
+
                         let generic_ty = self.tcx().type_of(def_id);
                         let concrete_ty = generic_ty.subst(self.tcx(), substs);
-                        self.fold_ty(concrete_ty)
+                        self.depth += 1;
+                        let folded_ty = self.fold_ty(concrete_ty);
+                        self.depth -= 1;
+                        folded_ty
                     }
                 }
             }
@@ -824,21 +838,12 @@ fn project_type<'cx, 'gcx, 'tcx>(
     // Drop duplicates.
     //
     // Note: `candidates.vec` seems to be on the critical path of the
-    // compiler. Replacing it with an hash set was also tried, which would
+    // compiler. Replacing it with an HashSet was also tried, which would
-    // render the following dedup unnecessary. It led to cleaner code but
+    // render the following dedup unnecessary. The original comment indicated
-    // prolonged compiling time of `librustc` from 5m30s to 6m in one test, or
+    // that it was 9% slower, but that data is now obsolete and a new
-    // ~9% performance lost.
+    // benchmark should be performed.
-    if candidates.vec.len() > 1 {
+    candidates.vec.sort_unstable();
-        let mut i = 0;
+    candidates.vec.dedup();
-        while i < candidates.vec.len() {
-            let has_dup = (0..i).any(|j| candidates.vec[i] == candidates.vec[j]);
-            if has_dup {
-                candidates.vec.swap_remove(i);
-            } else {
-                i += 1;
-            }
-        }
-    }
 
     // Prefer where-clauses. As in select, if there are multiple
     // candidates, we prefer where-clause candidates over impls.  This

src/librustc/ty/inhabitedness/mod.rs

@@ -262,10 +262,11 @@ impl<'a, 'gcx, 'tcx> TyS<'tcx> {
                 }))
             },
             TyArray(ty, len) => {
-                if len.val.to_const_int().and_then(|i| i.to_u64()) == Some(0) {
+                match len.val.to_const_int().and_then(|i| i.to_u64()) {
-                    DefIdForest::empty()
+                    // If the array is definitely non-empty, it's uninhabited if
-                } else {
+                    // the type of its elements is uninhabited.
-                    ty.uninhabited_from(visited, tcx)
+                    Some(n) if n != 0 => ty.uninhabited_from(visited, tcx),
+                    _ => DefIdForest::empty()
                 }
             }
             TyRef(_, ref tm) => {

src/librustc/ty/maps/config.rs

@@ -617,8 +617,8 @@ impl<'tcx> QueryDescription<'tcx> for queries::optimized_mir<'tcx> {
     }
 
     fn try_load_from_disk<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                          id: SerializedDepNodeIndex)
+                              id: SerializedDepNodeIndex)
-                          -> Option<Self::Value> {
+                              -> Option<Self::Value> {
         let mir: Option<::mir::Mir<'tcx>> = tcx.on_disk_query_result_cache
                                                .try_load_query_result(tcx, id);
         mir.map(|x| tcx.alloc_mir(x))
@@ -637,6 +637,27 @@ impl<'tcx> QueryDescription<'tcx> for queries::target_features_whitelist<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription<'tcx> for queries::instance_def_size_estimate<'tcx> {
+    fn describe(tcx: TyCtxt, def: ty::InstanceDef<'tcx>) -> String {
+        format!("estimating size for `{}`", tcx.item_path_str(def.def_id()))
+    }
+}
+
+impl<'tcx> QueryDescription<'tcx> for queries::generics_of<'tcx> {
+    #[inline]
+    fn cache_on_disk(def_id: Self::Key) -> bool {
+        def_id.is_local()
+    }
+
+    fn try_load_from_disk<'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                              id: SerializedDepNodeIndex)
+                              -> Option<Self::Value> {
+        let generics: Option<ty::Generics> = tcx.on_disk_query_result_cache
+                                                .try_load_query_result(tcx, id);
+        generics.map(|x| tcx.alloc_generics(x))
+    }
+}
+
 macro_rules! impl_disk_cacheable_query(
     ($query_name:ident, |$key:tt| $cond:expr) => {
         impl<'tcx> QueryDescription<'tcx> for queries::$query_name<'tcx> {
@@ -662,3 +683,6 @@ impl_disk_cacheable_query!(mir_const_qualif, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(check_match, |def_id| def_id.is_local());
 impl_disk_cacheable_query!(contains_extern_indicator, |_| true);
 impl_disk_cacheable_query!(def_symbol_name, |_| true);
+impl_disk_cacheable_query!(type_of, |def_id| def_id.is_local());
+impl_disk_cacheable_query!(predicates_of, |def_id| def_id.is_local());
+impl_disk_cacheable_query!(used_trait_imports, |def_id| def_id.is_local());

src/librustc/ty/maps/mod.rs

@@ -365,6 +365,9 @@ define_maps! { <'tcx>
         target_features_whitelist_node(CrateNum) -> Rc<FxHashSet<String>>,
     [] fn target_features_enabled: TargetFeaturesEnabled(DefId) -> Rc<Vec<String>>,
 
+    // Get an estimate of the size of an InstanceDef based on its MIR for CGU partitioning.
+    [] fn instance_def_size_estimate: instance_def_size_estimate_dep_node(ty::InstanceDef<'tcx>)
+        -> usize,
 }
 
 //////////////////////////////////////////////////////////////////////
@@ -514,3 +517,10 @@ fn substitute_normalize_and_test_predicates_node<'tcx>(key: (DefId, &'tcx Substs
 fn target_features_whitelist_node<'tcx>(_: CrateNum) -> DepConstructor<'tcx> {
     DepConstructor::TargetFeaturesWhitelist
 }
+
+fn instance_def_size_estimate_dep_node<'tcx>(instance_def: ty::InstanceDef<'tcx>)
+                                              -> DepConstructor<'tcx> {
+    DepConstructor::InstanceDefSizeEstimate {
+        instance_def
+    }
+}

src/librustc/ty/maps/on_disk_cache.rs

@@ -204,8 +204,12 @@ impl<'sess> OnDiskCache<'sess> {
                 let enc = &mut encoder;
                 let qri = &mut query_result_index;
 
-                // Encode TypeckTables
+                encode_query_results::<type_of, _>(tcx, enc, qri)?;
+                encode_query_results::<generics_of, _>(tcx, enc, qri)?;
+                encode_query_results::<predicates_of, _>(tcx, enc, qri)?;
+                encode_query_results::<used_trait_imports, _>(tcx, enc, qri)?;
                 encode_query_results::<typeck_tables_of, _>(tcx, enc, qri)?;
+                encode_query_results::<trans_fulfill_obligation, _>(tcx, enc, qri)?;
                 encode_query_results::<optimized_mir, _>(tcx, enc, qri)?;
                 encode_query_results::<unsafety_check_result, _>(tcx, enc, qri)?;
                 encode_query_results::<borrowck, _>(tcx, enc, qri)?;
@@ -215,7 +219,6 @@ impl<'sess> OnDiskCache<'sess> {
                 encode_query_results::<const_is_rvalue_promotable_to_static, _>(tcx, enc, qri)?;
                 encode_query_results::<contains_extern_indicator, _>(tcx, enc, qri)?;
                 encode_query_results::<symbol_name, _>(tcx, enc, qri)?;
-                encode_query_results::<trans_fulfill_obligation, _>(tcx, enc, qri)?;
                 encode_query_results::<check_match, _>(tcx, enc, qri)?;
             }
 

src/librustc/ty/maps/plumbing.rs

@@ -761,6 +761,7 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>,
         DepKind::EraseRegionsTy |
         DepKind::NormalizeTy |
         DepKind::SubstituteNormalizeAndTestPredicates |
+        DepKind::InstanceDefSizeEstimate |
 
         // This one should never occur in this context
         DepKind::Null => {
@@ -982,4 +983,8 @@ impl_load_from_cache!(
     ConstIsRvaluePromotableToStatic => const_is_rvalue_promotable_to_static,
     ContainsExternIndicator => contains_extern_indicator,
     CheckMatch => check_match,
+    TypeOfItem => type_of,
+    GenericsOfItem => generics_of,
+    PredicatesOfItem => predicates_of,
+    UsedTraitImports => used_trait_imports,
 );

src/librustc/ty/mod.rs

@@ -17,7 +17,7 @@ pub use self::fold::TypeFoldable;
 
 use hir::{map as hir_map, FreevarMap, TraitMap};
 use hir::def::{Def, CtorKind, ExportMap};
-use hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
+use hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use hir::map::DefPathData;
 use hir::svh::Svh;
 use ich::Fingerprint;
@@ -39,8 +39,8 @@ use util::nodemap::{NodeSet, DefIdMap, FxHashMap, FxHashSet};
 
 use serialize::{self, Encodable, Encoder};
 use std::cell::RefCell;
-use std::collections::BTreeMap;
 use std::cmp;
+use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
@@ -499,6 +499,20 @@ impl<'tcx> Hash for TyS<'tcx> {
     }
 }
 
+impl<'tcx> Ord for TyS<'tcx> {
+    #[inline]
+    fn cmp(&self, other: &TyS<'tcx>) -> Ordering {
+        // (self as *const _).cmp(other as *const _)
+        (self as *const TyS<'tcx>).cmp(&(other as *const TyS<'tcx>))
+    }
+}
+impl<'tcx> PartialOrd for TyS<'tcx> {
+    #[inline]
+    fn partial_cmp(&self, other: &TyS<'tcx>) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
 impl<'tcx> TyS<'tcx> {
     pub fn is_primitive_ty(&self) -> bool {
         match self.sty {
@@ -568,6 +582,19 @@ impl<T> PartialEq for Slice<T> {
 }
 impl<T> Eq for Slice<T> {}
 
+impl<T> Ord for Slice<T> {
+    #[inline]
+    fn cmp(&self, other: &Slice<T>) -> Ordering {
+        (&self.0 as *const [T]).cmp(&(&other.0 as *const [T]))
+    }
+}
+impl<T> PartialOrd for Slice<T> {
+    #[inline]
+    fn partial_cmp(&self, other: &Slice<T>) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
 impl<T> Hash for Slice<T> {
     fn hash<H: Hasher>(&self, s: &mut H) {
         (self.as_ptr(), self.len()).hash(s)
@@ -758,9 +785,8 @@ pub struct Generics {
     pub regions: Vec<RegionParameterDef>,
     pub types: Vec<TypeParameterDef>,
 
-    /// Reverse map to each `TypeParameterDef`'s `index` field, from
+    /// Reverse map to each `TypeParameterDef`'s `index` field
-    /// `def_id.index` (`def_id.krate` is the same as the item's).
+    pub type_param_to_index: FxHashMap<DefId, u32>,
-    pub type_param_to_index: BTreeMap<DefIndex, u32>,
 
     pub has_self: bool,
     pub has_late_bound_regions: Option<Span>,
@@ -1103,7 +1129,7 @@ pub type PolySubtypePredicate<'tcx> = ty::Binder<SubtypePredicate<'tcx>>;
 /// equality between arbitrary types. Processing an instance of
 /// Form #2 eventually yields one of these `ProjectionPredicate`
 /// instances to normalize the LHS.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
 pub struct ProjectionPredicate<'tcx> {
     pub projection_ty: ProjectionTy<'tcx>,
     pub ty: Ty<'tcx>,
@@ -2695,6 +2721,20 @@ fn crate_hash<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     tcx.hir.crate_hash
 }
 
+fn instance_def_size_estimate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                        instance_def: InstanceDef<'tcx>)
+                                        -> usize {
+    match instance_def {
+        InstanceDef::Item(..) |
+        InstanceDef::DropGlue(..) => {
+            let mir = tcx.instance_mir(instance_def);
+            mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum()
+        },
+        // Estimate the size of other compiler-generated shims to be 1.
+        _ => 1
+    }
+}
+
 pub fn provide(providers: &mut ty::maps::Providers) {
     context::provide(providers);
     erase_regions::provide(providers);
@@ -2712,6 +2752,7 @@ pub fn provide(providers: &mut ty::maps::Providers) {
         original_crate_name,
         crate_hash,
         trait_impls_of: trait_def::trait_impls_of_provider,
+        instance_def_size_estimate,
         ..*providers
     };
 }

src/librustc/ty/sty.rs

@@ -638,7 +638,7 @@ impl<'tcx> PolyExistentialTraitRef<'tcx> {
 /// erase, or otherwise "discharge" these bound regions, we change the
 /// type from `Binder<T>` to just `T` (see
 /// e.g. `liberate_late_bound_regions`).
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct Binder<T>(pub T);
 
 impl<T> Binder<T> {
@@ -738,7 +738,7 @@ impl<T> Binder<T> {
 
 /// Represents the projection of an associated type. In explicit UFCS
 /// form this would be written `<T as Trait<..>>::N`.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
 pub struct ProjectionTy<'tcx> {
     /// The parameters of the associated item.
     pub substs: &'tcx Substs<'tcx>,

src/librustc/ty/subst.rs

@@ -29,7 +29,7 @@ use std::mem;
 /// To reduce memory usage, a `Kind` is a interned pointer,
 /// with the lowest 2 bits being reserved for a tag to
 /// indicate the type (`Ty` or `Region`) it points to.
-#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Kind<'tcx> {
     ptr: NonZero<usize>,
     marker: PhantomData<(Ty<'tcx>, ty::Region<'tcx>)>

src/librustc_back/target/mod.rs

@@ -320,8 +320,8 @@ pub struct TargetOptions {
     /// Relocation model to use in object file. Corresponds to `llc
     /// -relocation-model=$relocation_model`. Defaults to "pic".
     pub relocation_model: String,
-    /// Code model to use. Corresponds to `llc -code-model=$code_model`. Defaults to "default".
+    /// Code model to use. Corresponds to `llc -code-model=$code_model`.
-    pub code_model: String,
+    pub code_model: Option<String>,
     /// TLS model to use. Options are "global-dynamic" (default), "local-dynamic", "initial-exec"
     /// and "local-exec". This is similar to the -ftls-model option in GCC/Clang.
     pub tls_model: String,
@@ -483,7 +483,7 @@ impl Default for TargetOptions {
             only_cdylib: false,
             executables: false,
             relocation_model: "pic".to_string(),
-            code_model: "default".to_string(),
+            code_model: None,
             tls_model: "global-dynamic".to_string(),
             disable_redzone: false,
             eliminate_frame_pointer: true,
@@ -736,7 +736,7 @@ impl Target {
         key!(only_cdylib, bool);
         key!(executables, bool);
         key!(relocation_model);
-        key!(code_model);
+        key!(code_model, optional);
         key!(tls_model);
         key!(disable_redzone, bool);
         key!(eliminate_frame_pointer, bool);

src/librustc_driver/lib.rs

@@ -87,11 +87,11 @@ use std::env;
 use std::ffi::OsString;
 use std::io::{self, Read, Write};
 use std::iter::repeat;
+use std::panic;
 use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::rc::Rc;
 use std::str;
-use std::sync::{Arc, Mutex};
 use std::thread;
 
 use syntax::ast;
@@ -168,7 +168,7 @@ pub fn run<F>(run_compiler: F) -> isize
                     handler.emit(&MultiSpan::new(),
                                  "aborting due to previous error(s)",
                                  errors::Level::Fatal);
-                    exit_on_err();
+                    panic::resume_unwind(Box::new(errors::FatalErrorMarker));
                 }
             }
         }
@@ -1228,27 +1228,16 @@ pub fn in_rustc_thread<F, R>(f: F) -> Result<R, Box<Any + Send>>
 /// The diagnostic emitter yielded to the procedure should be used for reporting
 /// errors of the compiler.
 pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
-    struct Sink(Arc<Mutex<Vec<u8>>>);
-    impl Write for Sink {
-        fn write(&mut self, data: &[u8]) -> io::Result<usize> {
-            Write::write(&mut *self.0.lock().unwrap(), data)
-        }
-        fn flush(&mut self) -> io::Result<()> {
-            Ok(())
-        }
-    }
-
-    let data = Arc::new(Mutex::new(Vec::new()));
-    let err = Sink(data.clone());
-
     let result = in_rustc_thread(move || {
-        io::set_panic(Some(box err));
         f()
     });
 
     if let Err(value) = result {
         // Thread panicked without emitting a fatal diagnostic
-        if !value.is::<errors::FatalError>() {
+        if !value.is::<errors::FatalErrorMarker>() {
+            // Emit a newline
+            eprintln!("");
+
             let emitter =
                 Box::new(errors::emitter::EmitterWriter::stderr(errors::ColorConfig::Auto,
                                                                 None,
@@ -1273,22 +1262,12 @@ pub fn monitor<F: FnOnce() + Send + 'static>(f: F) {
                              &note,
                              errors::Level::Note);
             }
-
-            eprintln!("{}", str::from_utf8(&data.lock().unwrap()).unwrap());
         }
 
-        exit_on_err();
+        panic::resume_unwind(Box::new(errors::FatalErrorMarker));
     }
 }
 
-fn exit_on_err() -> ! {
-    // Panic so the process returns a failure code, but don't pollute the
-    // output with some unnecessary panic messages, we've already
-    // printed everything that we needed to.
-    io::set_panic(Some(box io::sink()));
-    panic!();
-}
-
 #[cfg(stage0)]
 pub fn diagnostics_registry() -> errors::registry::Registry {
     use errors::registry::Registry;

src/librustc_errors/diagnostic.rs

@@ -27,7 +27,7 @@ pub struct Diagnostic {
     pub suggestions: Vec<CodeSuggestion>,
 }
 
-#[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
 pub enum DiagnosticId {
     Error(String),
     Lint(String),
@@ -281,6 +281,10 @@ impl Diagnostic {
         self
     }
 
+    pub fn get_code(&self) -> Option<DiagnosticId> {
+        self.code.clone()
+    }
+
     pub fn message(&self) -> String {
         self.message.iter().map(|i| i.0.to_owned()).collect::<String>()
     }

src/librustc_errors/lib.rs

@@ -19,6 +19,7 @@
 #![cfg_attr(unix, feature(libc))]
 #![feature(conservative_impl_trait)]
 #![feature(i128_type)]
+#![feature(optin_builtin_traits)]
 
 extern crate term;
 #[cfg(unix)]
@@ -44,6 +45,7 @@ use std::rc::Rc;
 use std::{error, fmt};
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering::SeqCst;
+use std::panic;
 
 mod diagnostic;
 mod diagnostic_builder;
@@ -201,6 +203,18 @@ impl CodeSuggestion {
 #[must_use]
 pub struct FatalError;
 
+pub struct FatalErrorMarker;
+
+// Don't implement Send on FatalError. This makes it impossible to panic!(FatalError).
+// We don't want to invoke the panic handler and print a backtrace for fatal errors.
+impl !Send for FatalError {}
+
+impl FatalError {
+    pub fn raise(self) -> ! {
+        panic::resume_unwind(Box::new(FatalErrorMarker))
+    }
+}
+
 impl fmt::Display for FatalError {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         write!(f, "parser fatal error")
@@ -245,6 +259,11 @@ pub struct Handler {
     delayed_span_bug: RefCell<Option<Diagnostic>>,
     tracked_diagnostics: RefCell<Option<Vec<Diagnostic>>>,
 
+    // This set contains the `DiagnosticId` of all emitted diagnostics to avoid
+    // emitting the same diagnostic with extended help (`--teach`) twice, which
+    // would be uneccessary repetition.
+    tracked_diagnostic_codes: RefCell<FxHashSet<DiagnosticId>>,
+
     // This set contains a hash of every diagnostic that has been emitted by
     // this handler. These hashes is used to avoid emitting the same error
     // twice.
@@ -303,6 +322,7 @@ impl Handler {
             continue_after_error: Cell::new(true),
             delayed_span_bug: RefCell::new(None),
             tracked_diagnostics: RefCell::new(None),
+            tracked_diagnostic_codes: RefCell::new(FxHashSet()),
             emitted_diagnostics: RefCell::new(FxHashSet()),
         }
     }
@@ -539,7 +559,7 @@ impl Handler {
             }
         }
 
-        panic!(self.fatal(&s));
+        self.fatal(&s).raise();
     }
     pub fn emit(&self, msp: &MultiSpan, msg: &str, lvl: Level) {
         if lvl == Warning && !self.flags.can_emit_warnings {
@@ -575,6 +595,14 @@ impl Handler {
         (ret, diagnostics)
     }
 
+    /// `true` if a diagnostic with this code has already been emitted in this handler.
+    ///
+    /// Used to suppress emitting the same error multiple times with extended explanation when
+    /// calling `-Zteach`.
+    pub fn code_emitted(&self, code: &DiagnosticId) -> bool {
+        self.tracked_diagnostic_codes.borrow().contains(code)
+    }
+
     fn emit_db(&self, db: &DiagnosticBuilder) {
         let diagnostic = &**db;
 
@@ -582,6 +610,10 @@ impl Handler {
             list.push(diagnostic.clone());
         }
 
+        if let Some(ref code) = diagnostic.code {
+            self.tracked_diagnostic_codes.borrow_mut().insert(code.clone());
+        }
+
         let diagnostic_hash = {
             use std::hash::Hash;
             let mut hasher = StableHasher::new();

src/librustc_llvm/ffi.rs

@@ -299,12 +299,11 @@ pub enum RelocMode {
 #[repr(C)]
 pub enum CodeModel {
     Other,
-    Default,
-    JITDefault,
     Small,
     Kernel,
     Medium,
     Large,
+    None,
 }
 
 /// LLVMRustDiagnosticKind
@@ -331,7 +330,6 @@ pub enum DiagnosticKind {
 pub enum ArchiveKind {
     Other,
     K_GNU,
-    K_MIPS64,
     K_BSD,
     K_COFF,
 }
@@ -498,6 +496,10 @@ pub mod debuginfo {
             const FlagStaticMember        = (1 << 12);
             const FlagLValueReference     = (1 << 13);
             const FlagRValueReference     = (1 << 14);
+            const FlagExternalTypeRef     = (1 << 15);
+            const FlagIntroducedVirtual   = (1 << 18);
+            const FlagBitField            = (1 << 19);
+            const FlagNoReturn            = (1 << 20);
             const FlagMainSubprogram      = (1 << 21);
         }
     }

src/librustc_llvm/lib.rs

@@ -105,7 +105,6 @@ impl FromStr for ArchiveKind {
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s {
             "gnu" => Ok(ArchiveKind::K_GNU),
-            "mips64" => Ok(ArchiveKind::K_MIPS64),
             "bsd" => Ok(ArchiveKind::K_BSD),
             "coff" => Ok(ArchiveKind::K_COFF),
             _ => Err(()),

src/librustc_mir/borrow_check/nll/type_check/mod.rs

@@ -681,6 +681,8 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
 
         let data = self.infcx.take_and_reset_region_constraints();
         if !data.is_empty() {
+            debug!("fully_perform_op: constraints generated at {:?} are {:#?}",
+                   locations, data);
             self.constraints
                 .outlives_sets
                 .push(OutlivesSet { locations, data });
@@ -1539,6 +1541,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
     where
         T: fmt::Debug + TypeFoldable<'tcx>,
     {
+        debug!("normalize(value={:?}, location={:?})", value, location);
         self.fully_perform_op(location.at_self(), |this| {
             let mut selcx = traits::SelectionContext::new(this.infcx);
             let cause = this.misc(this.last_span);

src/librustc_mir/monomorphize/partitioning.rs

@@ -115,6 +115,7 @@ use syntax::ast::NodeId;
 use syntax::symbol::{Symbol, InternedString};
 use rustc::mir::mono::MonoItem;
 use monomorphize::item::{MonoItemExt, InstantiationMode};
+use core::usize;
 
 pub use rustc::mir::mono::CodegenUnit;
 
@@ -224,6 +225,8 @@ pub fn partition<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let mut initial_partitioning = place_root_translation_items(tcx,
                                                                 trans_items);
 
+    initial_partitioning.codegen_units.iter_mut().for_each(|cgu| cgu.estimate_size(&tcx));
+
     debug_dump(tcx, "INITIAL PARTITIONING:", initial_partitioning.codegen_units.iter());
 
     // If the partitioning should produce a fixed count of codegen units, merge
@@ -241,6 +244,8 @@ pub fn partition<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let mut post_inlining = place_inlined_translation_items(initial_partitioning,
                                                             inlining_map);
 
+    post_inlining.codegen_units.iter_mut().for_each(|cgu| cgu.estimate_size(&tcx));
+
     debug_dump(tcx, "POST INLINING:", post_inlining.codegen_units.iter());
 
     // Next we try to make as many symbols "internal" as possible, so LLVM has
@@ -422,14 +427,13 @@ fn merge_codegen_units<'tcx>(initial_partitioning: &mut PreInliningPartitioning<
     codegen_units.sort_by_key(|cgu| cgu.name().clone());
 
     // Merge the two smallest codegen units until the target size is reached.
-    // Note that "size" is estimated here rather inaccurately as the number of
-    // translation items in a given unit. This could be improved on.
     while codegen_units.len() > target_cgu_count {
         // Sort small cgus to the back
-        codegen_units.sort_by_key(|cgu| -(cgu.items().len() as i64));
+        codegen_units.sort_by_key(|cgu| usize::MAX - cgu.size_estimate());
         let mut smallest = codegen_units.pop().unwrap();
         let second_smallest = codegen_units.last_mut().unwrap();
 
+        second_smallest.modify_size_estimate(smallest.size_estimate());
         for (k, v) in smallest.items_mut().drain() {
             second_smallest.items_mut().insert(k, v);
         }

src/librustc_passes/ast_validation.rs

@@ -141,14 +141,6 @@ impl<'a> AstValidator<'a> {
 impl<'a> Visitor<'a> for AstValidator<'a> {
     fn visit_expr(&mut self, expr: &'a Expr) {
         match expr.node {
-            ExprKind::While(.., Some(ident)) |
-            ExprKind::Loop(_, Some(ident)) |
-            ExprKind::WhileLet(.., Some(ident)) |
-            ExprKind::ForLoop(.., Some(ident)) |
-            ExprKind::Break(Some(ident), _) |
-            ExprKind::Continue(Some(ident)) => {
-                self.check_label(ident.node, ident.span);
-            }
             ExprKind::InlineAsm(..) if !self.session.target.target.options.allow_asm => {
                 span_err!(self.session, expr.span, E0472, "asm! is unsupported on this target");
             }
@@ -211,6 +203,11 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         visit::walk_use_tree(self, use_tree, id);
     }
 
+    fn visit_label(&mut self, label: &'a Label) {
+        self.check_label(label.ident, label.span);
+        visit::walk_label(self, label);
+    }
+
     fn visit_lifetime(&mut self, lifetime: &'a Lifetime) {
         self.check_lifetime(lifetime);
         visit::walk_lifetime(self, lifetime);

src/librustc_resolve/lib.rs

@@ -55,7 +55,7 @@ use syntax::attr;
 use syntax::ast::{Arm, BindingMode, Block, Crate, Expr, ExprKind};
 use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParam, Generics};
 use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
-use syntax::ast::{Local, Mutability, Pat, PatKind, Path};
+use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
 use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
 use syntax::feature_gate::{feature_err, emit_feature_err, GateIssue};
 use syntax::parse::token;
@@ -2045,7 +2045,7 @@ impl<'a> Resolver<'a> {
                     segments: vec![],
                     span: use_tree.span,
                 };
-                self.resolve_use_tree(item, use_tree, &path);
+                self.resolve_use_tree(item.id, use_tree, &path);
             }
 
             ItemKind::ExternCrate(_) | ItemKind::MacroDef(..) | ItemKind::GlobalAsm(_) => {
@@ -2056,7 +2056,7 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn resolve_use_tree(&mut self, item: &Item, use_tree: &ast::UseTree, prefix: &Path) {
+    fn resolve_use_tree(&mut self, id: NodeId, use_tree: &ast::UseTree, prefix: &Path) {
         match use_tree.kind {
             ast::UseTreeKind::Nested(ref items) => {
                 let path = Path {
@@ -2070,10 +2070,10 @@ impl<'a> Resolver<'a> {
 
                 if items.len() == 0 {
                     // Resolve prefix of an import with empty braces (issue #28388).
-                    self.smart_resolve_path(item.id, None, &path, PathSource::ImportPrefix);
+                    self.smart_resolve_path(id, None, &path, PathSource::ImportPrefix);
                 } else {
-                    for &(ref tree, _) in items {
+                    for &(ref tree, nested_id) in items {
-                        self.resolve_use_tree(item, tree, &path);
+                        self.resolve_use_tree(nested_id, tree, &path);
                     }
                 }
             }
@@ -3415,13 +3415,13 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn with_resolved_label<F>(&mut self, label: Option<SpannedIdent>, id: NodeId, f: F)
+    fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
         where F: FnOnce(&mut Resolver)
     {
         if let Some(label) = label {
             let def = Def::Label(id);
             self.with_label_rib(|this| {
-                this.label_ribs.last_mut().unwrap().bindings.insert(label.node, def);
+                this.label_ribs.last_mut().unwrap().bindings.insert(label.ident, def);
                 f(this);
             });
         } else {
@@ -3429,7 +3429,7 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn resolve_labeled_block(&mut self, label: Option<SpannedIdent>, id: NodeId, block: &Block) {
+    fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
         self.with_resolved_label(label, id, |this| this.visit_block(block));
     }
 
@@ -3452,19 +3452,19 @@ impl<'a> Resolver<'a> {
             }
 
             ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
-                match self.search_label(label.node, |rib, id| rib.bindings.get(&id).cloned()) {
+                match self.search_label(label.ident, |rib, id| rib.bindings.get(&id).cloned()) {
                     None => {
                         // Search again for close matches...
                         // Picks the first label that is "close enough", which is not necessarily
                         // the closest match
-                        let close_match = self.search_label(label.node, |rib, ident| {
+                        let close_match = self.search_label(label.ident, |rib, ident| {
                             let names = rib.bindings.iter().map(|(id, _)| &id.name);
                             find_best_match_for_name(names, &*ident.name.as_str(), None)
                         });
                         self.record_def(expr.id, err_path_resolution());
                         resolve_error(self,
                                       label.span,
-                                      ResolutionError::UndeclaredLabel(&label.node.name.as_str(),
+                                      ResolutionError::UndeclaredLabel(&label.ident.name.as_str(),
                                                                        close_match));
                     }
                     Some(def @ Def::Label(_)) => {

src/librustc_trans/abi.rs

@@ -871,6 +871,31 @@ impl<'a, 'tcx> FnType<'tcx> {
 
                 match arg.layout.abi {
                     layout::Abi::Aggregate { .. } => {}
+
+                    // This is a fun case! The gist of what this is doing is
+                    // that we want callers and callees to always agree on the
+                    // ABI of how they pass SIMD arguments. If we were to *not*
+                    // make these arguments indirect then they'd be immediates
+                    // in LLVM, which means that they'd used whatever the
+                    // appropriate ABI is for the callee and the caller. That
+                    // means, for example, if the caller doesn't have AVX
+                    // enabled but the callee does, then passing an AVX argument
+                    // across this boundary would cause corrupt data to show up.
+                    //
+                    // This problem is fixed by unconditionally passing SIMD
+                    // arguments through memory between callers and callees
+                    // which should get them all to agree on ABI regardless of
+                    // target feature sets. Some more information about this
+                    // issue can be found in #44367.
+                    //
+                    // Note that the platform intrinsic ABI is exempt here as
+                    // that's how we connect up to LLVM and it's unstable
+                    // anyway, we control all calls to it in libstd.
+                    layout::Abi::Vector { .. } if abi != Abi::PlatformIntrinsic => {
+                        arg.make_indirect();
+                        return
+                    }
+
                     _ => return
                 }
 

src/librustc_trans/back/link.rs

@@ -16,7 +16,7 @@ use super::rpath::RPathConfig;
 use super::rpath;
 use metadata::METADATA_FILENAME;
 use rustc::session::config::{self, NoDebugInfo, OutputFilenames, OutputType, PrintRequest};
-use rustc::session::config::RUST_CGU_EXT;
+use rustc::session::config::{RUST_CGU_EXT, Lto};
 use rustc::session::filesearch;
 use rustc::session::search_paths::PathKind;
 use rustc::session::Session;
@@ -503,7 +503,8 @@ fn link_staticlib(sess: &Session,
         });
         ab.add_rlib(path,
                     &name.as_str(),
-                    sess.lto() && !ignored_for_lto(sess, &trans.crate_info, cnum),
+                    is_full_lto_enabled(sess) &&
+                        !ignored_for_lto(sess, &trans.crate_info, cnum),
                     skip_object_files).unwrap();
 
         all_native_libs.extend(trans.crate_info.native_libraries[&cnum].iter().cloned());
@@ -1211,7 +1212,8 @@ fn add_upstream_rust_crates(cmd: &mut Linker,
             lib.kind == NativeLibraryKind::NativeStatic && !relevant_lib(sess, lib)
         });
 
-        if (!sess.lto() || ignored_for_lto(sess, &trans.crate_info, cnum)) &&
+        if (!is_full_lto_enabled(sess) ||
+            ignored_for_lto(sess, &trans.crate_info, cnum)) &&
            crate_type != config::CrateTypeDylib &&
            !skip_native {
             cmd.link_rlib(&fix_windows_verbatim_for_gcc(cratepath));
@@ -1264,7 +1266,7 @@ fn add_upstream_rust_crates(cmd: &mut Linker,
                 // file, then we don't need the object file as it's part of the
                 // LTO module. Note that `#![no_builtins]` is excluded from LTO,
                 // though, so we let that object file slide.
-                let skip_because_lto = sess.lto() &&
+                let skip_because_lto = is_full_lto_enabled(sess) &&
                     is_rust_object &&
                     (sess.target.target.options.no_builtins ||
                      !trans.crate_info.is_no_builtins.contains(&cnum));
@@ -1301,7 +1303,7 @@ fn add_upstream_rust_crates(cmd: &mut Linker,
     fn add_dynamic_crate(cmd: &mut Linker, sess: &Session, cratepath: &Path) {
         // If we're performing LTO, then it should have been previously required
         // that all upstream rust dependencies were available in an rlib format.
-        assert!(!sess.lto());
+        assert!(!is_full_lto_enabled(sess));
 
         // Just need to tell the linker about where the library lives and
         // what its name is
@@ -1409,3 +1411,13 @@ fn link_binaryen(sess: &Session,
                             e));
     }
 }
+
+fn is_full_lto_enabled(sess: &Session) -> bool {
+    match sess.lto() {
+        Lto::Yes |
+        Lto::Thin |
+        Lto::Fat => true,
+        Lto::No |
+        Lto::ThinLocal => false,
+    }
+}

src/librustc_trans/back/lto.rs

@@ -18,7 +18,7 @@ use llvm::{ModuleRef, TargetMachineRef, True, False};
 use llvm;
 use rustc::hir::def_id::LOCAL_CRATE;
 use rustc::middle::exported_symbols::SymbolExportLevel;
-use rustc::session::config;
+use rustc::session::config::{self, Lto};
 use rustc::util::common::time;
 use time_graph::Timeline;
 use {ModuleTranslation, ModuleLlvm, ModuleKind, ModuleSource};
@@ -95,25 +95,22 @@ impl LtoModuleTranslation {
     }
 }
 
-pub enum LTOMode {
-    WholeCrateGraph,
-    JustThisCrate,
-}
-
 pub(crate) fn run(cgcx: &CodegenContext,
-           modules: Vec<ModuleTranslation>,
+                  modules: Vec<ModuleTranslation>,
-           mode: LTOMode,
+                  timeline: &mut Timeline)
-           timeline: &mut Timeline)
     -> Result<Vec<LtoModuleTranslation>, FatalError>
 {
     let diag_handler = cgcx.create_diag_handler();
-    let export_threshold = match mode {
+    let export_threshold = match cgcx.lto {
-        LTOMode::WholeCrateGraph => {
+        // We're just doing LTO for our one crate
+        Lto::ThinLocal => SymbolExportLevel::Rust,
+
+        // We're doing LTO for the entire crate graph
+        Lto::Yes | Lto::Fat | Lto::Thin => {
             symbol_export::crates_export_threshold(&cgcx.crate_types)
         }
-        LTOMode::JustThisCrate => {
+
-            SymbolExportLevel::Rust
+        Lto::No => panic!("didn't request LTO but we're doing LTO"),
-        }
     };
 
     let symbol_filter = &|&(ref name, _, level): &(String, _, SymbolExportLevel)| {
@@ -140,7 +137,7 @@ pub(crate) fn run(cgcx: &CodegenContext,
     // We save off all the bytecode and LLVM module ids for later processing
     // with either fat or thin LTO
     let mut upstream_modules = Vec::new();
-    if let LTOMode::WholeCrateGraph = mode {
+    if cgcx.lto != Lto::ThinLocal {
         if cgcx.opts.cg.prefer_dynamic {
             diag_handler.struct_err("cannot prefer dynamic linking when performing LTO")
                         .note("only 'staticlib', 'bin', and 'cdylib' outputs are \
@@ -186,13 +183,16 @@ pub(crate) fn run(cgcx: &CodegenContext,
     }
 
     let arr = symbol_white_list.iter().map(|c| c.as_ptr()).collect::<Vec<_>>();
-    match mode {
+    match cgcx.lto {
-        LTOMode::WholeCrateGraph if !cgcx.thinlto => {
+        Lto::Yes | // `-C lto` == fat LTO by default
+        Lto::Fat => {
             fat_lto(cgcx, &diag_handler, modules, upstream_modules, &arr, timeline)
         }
-        _ => {
+        Lto::Thin |
+        Lto::ThinLocal => {
             thin_lto(&diag_handler, modules, upstream_modules, &arr, timeline)
         }
+        Lto::No => unreachable!(),
     }
 }
 

src/librustc_trans/back/write.rs

@@ -11,6 +11,7 @@
 use back::bytecode::{self, RLIB_BYTECODE_EXTENSION};
 use back::lto::{self, ModuleBuffer, ThinBuffer};
 use back::link::{self, get_linker, remove};
+use back::command::Command;
 use back::linker::LinkerInfo;
 use back::symbol_export::ExportedSymbols;
 use base;
@@ -18,8 +19,8 @@ use consts;
 use rustc_incremental::{save_trans_partition, in_incr_comp_dir};
 use rustc::dep_graph::{DepGraph, WorkProductFileKind};
 use rustc::middle::cstore::{LinkMeta, EncodedMetadata};
-use rustc::session::config::{self, OutputFilenames, OutputType, OutputTypes, Passes, SomePasses,
+use rustc::session::config::{self, OutputFilenames, OutputType, Passes, SomePasses,
-                             AllPasses, Sanitizer};
+                             AllPasses, Sanitizer, Lto};
 use rustc::session::Session;
 use rustc::util::nodemap::FxHashMap;
 use rustc_back::LinkerFlavor;
@@ -32,7 +33,7 @@ use CrateInfo;
 use rustc::hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc::ty::TyCtxt;
 use rustc::util::common::{time, time_depth, set_time_depth, path2cstr, print_time_passes_entry};
-use rustc::util::fs::{link_or_copy, rename_or_copy_remove};
+use rustc::util::fs::{link_or_copy};
 use errors::{self, Handler, Level, DiagnosticBuilder, FatalError, DiagnosticId};
 use errors::emitter::{Emitter};
 use syntax::attr;
@@ -68,8 +69,7 @@ pub const RELOC_MODEL_ARGS : [(&'static str, llvm::RelocMode); 7] = [
     ("ropi-rwpi", llvm::RelocMode::ROPI_RWPI),
 ];
 
-pub const CODE_GEN_MODEL_ARGS : [(&'static str, llvm::CodeModel); 5] = [
+pub const CODE_GEN_MODEL_ARGS: &[(&str, llvm::CodeModel)] = &[
-    ("default", llvm::CodeModel::Default),
     ("small", llvm::CodeModel::Small),
     ("kernel", llvm::CodeModel::Kernel),
     ("medium", llvm::CodeModel::Medium),
@@ -155,7 +155,7 @@ fn get_llvm_opt_size(optimize: config::OptLevel) -> llvm::CodeGenOptSize {
 
 pub fn create_target_machine(sess: &Session) -> TargetMachineRef {
     target_machine_factory(sess)().unwrap_or_else(|err| {
-        panic!(llvm_err(sess.diagnostic(), err))
+        llvm_err(sess.diagnostic(), err).raise()
     })
 }
 
@@ -170,20 +170,23 @@ pub fn target_machine_factory(sess: &Session)
     let ffunction_sections = sess.target.target.options.function_sections;
     let fdata_sections = ffunction_sections;
 
-    let code_model_arg = match sess.opts.cg.code_model {
+    let code_model_arg = sess.opts.cg.code_model.as_ref().or(
-        Some(ref s) => &s,
+        sess.target.target.options.code_model.as_ref(),
-        None => &sess.target.target.options.code_model,
+    );
-    };
 
-    let code_model = match CODE_GEN_MODEL_ARGS.iter().find(
+    let code_model = match code_model_arg {
-        |&&arg| arg.0 == code_model_arg) {
+        Some(s) => {
-        Some(x) => x.1,
+            match CODE_GEN_MODEL_ARGS.iter().find(|arg| arg.0 == s) {
-        _ => {
+                Some(x) => x.1,
-            sess.err(&format!("{:?} is not a valid code model",
+                _ => {
-                              code_model_arg));
+                    sess.err(&format!("{:?} is not a valid code model",
-            sess.abort_if_errors();
+                                      code_model_arg));
-            bug!();
+                    sess.abort_if_errors();
+                    bug!();
+                }
+            }
         }
+        None => llvm::CodeModel::None,
     };
 
     let singlethread = sess.target.target.options.singlethread;
@@ -258,6 +261,7 @@ pub struct ModuleConfig {
     // make the object file bitcode. Provides easy compatibility with
     // emscripten's ecc compiler, when used as the linker.
     obj_is_bitcode: bool,
+    no_integrated_as: bool,
 }
 
 impl ModuleConfig {
@@ -275,6 +279,7 @@ impl ModuleConfig {
             emit_asm: false,
             emit_obj: false,
             obj_is_bitcode: false,
+            no_integrated_as: false,
 
             no_verify: false,
             no_prepopulate_passes: false,
@@ -313,13 +318,18 @@ impl ModuleConfig {
     }
 }
 
+/// Assembler name and command used by codegen when no_integrated_as is enabled
+struct AssemblerCommand {
+    name: PathBuf,
+    cmd: Command,
+}
+
 /// Additional resources used by optimize_and_codegen (not module specific)
 #[derive(Clone)]
 pub struct CodegenContext {
     // Resouces needed when running LTO
     pub time_passes: bool,
-    pub lto: bool,
+    pub lto: Lto,
-    pub thinlto: bool,
     pub no_landing_pads: bool,
     pub save_temps: bool,
     pub fewer_names: bool,
@@ -356,6 +366,8 @@ pub struct CodegenContext {
     // A reference to the TimeGraph so we can register timings. None means that
     // measuring is disabled.
     time_graph: Option<TimeGraph>,
+    // The assembler command if no_integrated_as option is enabled, None otherwise
+    assembler_cmd: Option<Arc<AssemblerCommand>>,
 }
 
 impl CodegenContext {
@@ -576,13 +588,8 @@ fn generate_lto_work(cgcx: &CodegenContext,
                  TRANS_WORK_PACKAGE_KIND,
                  "generate lto")
     }).unwrap_or(Timeline::noop());
-    let mode = if cgcx.lto {
+    let lto_modules = lto::run(cgcx, modules, &mut timeline)
-        lto::LTOMode::WholeCrateGraph
+        .unwrap_or_else(|e| e.raise());
-    } else {
-        lto::LTOMode::JustThisCrate
-    };
-    let lto_modules = lto::run(cgcx, modules, mode, &mut timeline)
-        .unwrap_or_else(|e| panic!(e));
 
     lto_modules.into_iter().map(|module| {
         let cost = module.cost();
@@ -639,13 +646,17 @@ unsafe fn codegen(cgcx: &CodegenContext,
         !cgcx.crate_types.contains(&config::CrateTypeRlib) &&
         mtrans.kind == ModuleKind::Regular;
 
+    // If we don't have the integrated assembler, then we need to emit asm
+    // from LLVM and use `gcc` to create the object file.
+    let asm_to_obj = config.emit_obj && config.no_integrated_as;
+
     // Change what we write and cleanup based on whether obj files are
     // just llvm bitcode. In that case write bitcode, and possibly
     // delete the bitcode if it wasn't requested. Don't generate the
     // machine code, instead copy the .o file from the .bc
     let write_bc = config.emit_bc || (config.obj_is_bitcode && !asm2wasm);
     let rm_bc = !config.emit_bc && config.obj_is_bitcode && !asm2wasm;
-    let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm2wasm;
+    let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm2wasm && !asm_to_obj;
     let copy_bc_to_obj = config.emit_obj && config.obj_is_bitcode && !asm2wasm;
 
     let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
@@ -725,13 +736,13 @@ unsafe fn codegen(cgcx: &CodegenContext,
             timeline.record("ir");
         }
 
-        if config.emit_asm || (asm2wasm && config.emit_obj) {
+        if config.emit_asm || (asm2wasm && config.emit_obj) || asm_to_obj {
             let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
 
             // We can't use the same module for asm and binary output, because that triggers
             // various errors like invalid IR or broken binaries, so we might have to clone the
             // module to produce the asm output
-            let llmod = if config.emit_obj {
+            let llmod = if config.emit_obj && !asm2wasm {
                 llvm::LLVMCloneModule(llmod)
             } else {
                 llmod
@@ -740,7 +751,7 @@ unsafe fn codegen(cgcx: &CodegenContext,
                 write_output_file(diag_handler, tm, cpm, llmod, &path,
                                   llvm::FileType::AssemblyFile)
             })?;
-            if config.emit_obj {
+            if config.emit_obj && !asm2wasm {
                 llvm::LLVMDisposeModule(llmod);
             }
             timeline.record("asm");
@@ -760,6 +771,14 @@ unsafe fn codegen(cgcx: &CodegenContext,
                                   llvm::FileType::ObjectFile)
             })?;
             timeline.record("obj");
+        } else if asm_to_obj {
+            let assembly = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
+            run_assembler(cgcx, diag_handler, &assembly, &obj_out);
+            timeline.record("asm_to_obj");
+
+            if !config.emit_asm && !cgcx.save_temps {
+                drop(fs::remove_file(&assembly));
+            }
         }
 
         Ok(())
@@ -841,7 +860,6 @@ pub fn start_async_translation(tcx: TyCtxt,
                                total_cgus: usize)
                                -> OngoingCrateTranslation {
     let sess = tcx.sess;
-    let crate_output = tcx.output_filenames(LOCAL_CRATE);
     let crate_name = tcx.crate_name(LOCAL_CRATE);
     let no_builtins = attr::contains_name(&tcx.hir.krate().attrs, "no_builtins");
     let subsystem = attr::first_attr_value_str_by_name(&tcx.hir.krate().attrs,
@@ -855,19 +873,9 @@ pub fn start_async_translation(tcx: TyCtxt,
         subsystem.to_string()
     });
 
-    let no_integrated_as = tcx.sess.opts.cg.no_integrated_as ||
-        (tcx.sess.target.target.options.no_integrated_as &&
-         (crate_output.outputs.contains_key(&OutputType::Object) ||
-          crate_output.outputs.contains_key(&OutputType::Exe)));
     let linker_info = LinkerInfo::new(tcx);
     let crate_info = CrateInfo::new(tcx);
 
-    let output_types_override = if no_integrated_as {
-        OutputTypes::new(&[(OutputType::Assembly, None)])
-    } else {
-        sess.opts.output_types.clone()
-    };
-
     // Figure out what we actually need to build.
     let mut modules_config = ModuleConfig::new(sess.opts.cg.passes.clone());
     let mut metadata_config = ModuleConfig::new(vec![]);
@@ -913,7 +921,10 @@ pub fn start_async_translation(tcx: TyCtxt,
         allocator_config.emit_bc_compressed = true;
     }
 
-    for output_type in output_types_override.keys() {
+    modules_config.no_integrated_as = tcx.sess.opts.cg.no_integrated_as ||
+        tcx.sess.target.target.options.no_integrated_as;
+
+    for output_type in sess.opts.output_types.keys() {
         match *output_type {
             OutputType::Bitcode => { modules_config.emit_bc = true; }
             OutputType::LlvmAssembly => { modules_config.emit_ir = true; }
@@ -976,7 +987,6 @@ pub fn start_async_translation(tcx: TyCtxt,
         metadata,
         windows_subsystem,
         linker_info,
-        no_integrated_as,
         crate_info,
 
         time_graph,
@@ -1280,28 +1290,51 @@ fn execute_work_item(cgcx: &CodegenContext,
         unsafe {
             optimize(cgcx, &diag_handler, &mtrans, config, timeline)?;
 
-            let lto = cgcx.lto;
+            // After we've done the initial round of optimizations we need to
-
+            // decide whether to synchronously codegen this module or ship it
-            let auto_thin_lto =
+            // back to the coordinator thread for further LTO processing (which
-                cgcx.thinlto &&
+            // has to wait for all the initial modules to be optimized).
-                cgcx.total_cgus > 1 &&
-                mtrans.kind != ModuleKind::Allocator;
-
-            // If we're a metadata module we never participate in LTO.
             //
-            // If LTO was explicitly requested on the command line, we always
+            // Here we dispatch based on the `cgcx.lto` and kind of module we're
-            // LTO everything else.
+            // translating...
-            //
+            let needs_lto = match cgcx.lto {
-            // If LTO *wasn't* explicitly requested and we're not a metdata
+                Lto::No => false,
-            // module, then we may automatically do ThinLTO if we've got
+
-            // multiple codegen units. Note, however, that the allocator module
+                // Here we've got a full crate graph LTO requested. We ignore
-            // doesn't participate here automatically because of linker
+                // this, however, if the crate type is only an rlib as there's
-            // shenanigans later on.
+                // no full crate graph to process, that'll happen later.
-            if mtrans.kind == ModuleKind::Metadata || (!lto && !auto_thin_lto) {
+                //
+                // This use case currently comes up primarily for targets that
+                // require LTO so the request for LTO is always unconditionally
+                // passed down to the backend, but we don't actually want to do
+                // anything about it yet until we've got a final product.
+                Lto::Yes | Lto::Fat | Lto::Thin => {
+                    cgcx.crate_types.len() != 1 ||
+                        cgcx.crate_types[0] != config::CrateTypeRlib
+                }
+
+                // When we're automatically doing ThinLTO for multi-codegen-unit
+                // builds we don't actually want to LTO the allocator modules if
+                // it shows up. This is due to various linker shenanigans that
+                // we'll encounter later.
+                //
+                // Additionally here's where we also factor in the current LLVM
+                // version. If it doesn't support ThinLTO we skip this.
+                Lto::ThinLocal => {
+                    mtrans.kind != ModuleKind::Allocator &&
+                        llvm::LLVMRustThinLTOAvailable()
+                }
+            };
+
+            // Metadata modules never participate in LTO regardless of the lto
+            // settings.
+            let needs_lto = needs_lto && mtrans.kind != ModuleKind::Metadata;
+
+            if needs_lto {
+                Ok(WorkItemResult::NeedsLTO(mtrans))
+            } else {
                 let module = codegen(cgcx, &diag_handler, mtrans, config, timeline)?;
                 Ok(WorkItemResult::Compiled(module))
-            } else {
-                Ok(WorkItemResult::NeedsLTO(mtrans))
             }
         }
     }
@@ -1377,28 +1410,25 @@ fn start_executing_work(tcx: TyCtxt,
         each_linked_rlib_for_lto.push((cnum, path.to_path_buf()));
     }));
 
-    let crate_types = sess.crate_types.borrow();
-    let only_rlib = crate_types.len() == 1 &&
-        crate_types[0] == config::CrateTypeRlib;
-
     let wasm_import_memory =
         attr::contains_name(&tcx.hir.krate().attrs, "wasm_import_memory");
 
+    let assembler_cmd = if modules_config.no_integrated_as {
+        // HACK: currently we use linker (gcc) as our assembler
+        let (name, mut cmd, _) = get_linker(sess);
+        cmd.args(&sess.target.target.options.asm_args);
+        Some(Arc::new(AssemblerCommand {
+            name,
+            cmd,
+        }))
+    } else {
+        None
+    };
+
     let cgcx = CodegenContext {
         crate_types: sess.crate_types.borrow().clone(),
         each_linked_rlib_for_lto,
-        // If we're only building an rlibc then allow the LTO flag to be passed
+        lto: sess.lto(),
-        // but don't actually do anything, the full LTO will happen later
-        lto: sess.lto() && !only_rlib,
-
-        // Enable ThinLTO if requested, but only if the target we're compiling
-        // for doesn't require full LTO. Some targets require one LLVM module
-        // (they effectively don't have a linker) so it's up to us to use LTO to
-        // link everything together.
-        thinlto: sess.thinlto() &&
-            !sess.target.target.options.requires_lto &&
-            unsafe { llvm::LLVMRustThinLTOAvailable() },
-
         no_landing_pads: sess.no_landing_pads(),
         fewer_names: sess.fewer_names(),
         save_temps: sess.opts.cg.save_temps,
@@ -1423,6 +1453,7 @@ fn start_executing_work(tcx: TyCtxt,
         binaryen_linker: tcx.sess.linker_flavor() == LinkerFlavor::Binaryen,
         debuginfo: tcx.sess.opts.debuginfo,
         wasm_import_memory: wasm_import_memory,
+        assembler_cmd,
     };
 
     // This is the "main loop" of parallel work happening for parallel codegen.
@@ -1931,15 +1962,14 @@ fn spawn_work(cgcx: CodegenContext, work: WorkItem) {
     });
 }
 
-pub fn run_assembler(sess: &Session, outputs: &OutputFilenames) {
+pub fn run_assembler(cgcx: &CodegenContext, handler: &Handler, assembly: &Path, object: &Path) {
-    let (pname, mut cmd, _) = get_linker(sess);
+    let assembler = cgcx.assembler_cmd
+        .as_ref()
+        .expect("cgcx.assembler_cmd is missing?");
 
-    for arg in &sess.target.target.options.asm_args {
+    let pname = &assembler.name;
-        cmd.arg(arg);
+    let mut cmd = assembler.cmd.clone();
-    }
+    cmd.arg("-c").arg("-o").arg(object).arg(assembly);
-
-    cmd.arg("-c").arg("-o").arg(&outputs.path(OutputType::Object))
-                           .arg(&outputs.temp_path(OutputType::Assembly, None));
     debug!("{:?}", cmd);
 
     match cmd.output() {
@@ -1948,18 +1978,18 @@ pub fn run_assembler(sess: &Session, outputs: &OutputFilenames) {
                 let mut note = prog.stderr.clone();
                 note.extend_from_slice(&prog.stdout);
 
-                sess.struct_err(&format!("linking with `{}` failed: {}",
+                handler.struct_err(&format!("linking with `{}` failed: {}",
-                                         pname.display(),
+                                            pname.display(),
-                                         prog.status))
+                                            prog.status))
                     .note(&format!("{:?}", &cmd))
                     .note(str::from_utf8(&note[..]).unwrap())
                     .emit();
-                sess.abort_if_errors();
+                handler.abort_if_errors();
             }
         },
         Err(e) => {
-            sess.err(&format!("could not exec the linker `{}`: {}", pname.display(), e));
+            handler.err(&format!("could not exec the linker `{}`: {}", pname.display(), e));
-            sess.abort_if_errors();
+            handler.abort_if_errors();
         }
     }
 }
@@ -2133,7 +2163,6 @@ pub struct OngoingCrateTranslation {
     metadata: EncodedMetadata,
     windows_subsystem: Option<String>,
     linker_info: LinkerInfo,
-    no_integrated_as: bool,
     crate_info: CrateInfo,
     time_graph: Option<TimeGraph>,
     coordinator_send: Sender<Box<Any + Send>>,
@@ -2189,26 +2218,6 @@ impl OngoingCrateTranslation {
             metadata_module: compiled_modules.metadata_module,
         };
 
-        if self.no_integrated_as {
-            run_assembler(sess,  &self.output_filenames);
-
-            // HACK the linker expects the object file to be named foo.0.o but
-            // `run_assembler` produces an object named just foo.o. Rename it if we
-            // are going to build an executable
-            if sess.opts.output_types.contains_key(&OutputType::Exe) {
-                let f =  self.output_filenames.path(OutputType::Object);
-                rename_or_copy_remove(&f,
-                    f.with_file_name(format!("{}.0.o",
-                                             f.file_stem().unwrap().to_string_lossy()))).unwrap();
-            }
-
-            // Remove assembly source, unless --save-temps was specified
-            if !sess.opts.cg.save_temps {
-                fs::remove_file(&self.output_filenames
-                                     .temp_path(OutputType::Assembly, None)).unwrap();
-            }
-        }
-
         trans
     }
 

src/librustc_trans/base.rs

@@ -78,7 +78,7 @@ use std::ffi::CString;
 use std::str;
 use std::sync::Arc;
 use std::time::{Instant, Duration};
-use std::i32;
+use std::{i32, usize};
 use std::iter;
 use std::sync::mpsc;
 use syntax_pos::Span;
@@ -823,12 +823,10 @@ pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     ongoing_translation.submit_pre_translated_module_to_llvm(tcx, metadata_module);
 
     // We sort the codegen units by size. This way we can schedule work for LLVM
-    // a bit more efficiently. Note that "size" is defined rather crudely at the
+    // a bit more efficiently.
-    // moment as it is just the number of TransItems in the CGU, not taking into
-    // account the size of each TransItem.
     let codegen_units = {
         let mut codegen_units = codegen_units;
-        codegen_units.sort_by_key(|cgu| -(cgu.items().len() as isize));
+        codegen_units.sort_by_key(|cgu| usize::MAX - cgu.size_estimate());
         codegen_units
     };
 

src/librustc_trans/cabi_x86_64.rs

@@ -16,9 +16,11 @@ use context::CodegenCx;
 
 use rustc::ty::layout::{self, TyLayout, Size};
 
-#[derive(Clone, Copy, PartialEq, Debug)]
+/// Classification of "eightbyte" components.
+// NB: the order of the variants is from general to specific,
+// such that `unify(a, b)` is the "smaller" of `a` and `b`.
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)]
 enum Class {
-    None,
     Int,
     Sse,
     SseUp
@@ -32,29 +34,10 @@ const LARGEST_VECTOR_SIZE: usize = 512;
 const MAX_EIGHTBYTES: usize = LARGEST_VECTOR_SIZE / 64;
 
 fn classify_arg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, arg: &ArgType<'tcx>)
-                          -> Result<[Class; MAX_EIGHTBYTES], Memory> {
+                          -> Result<[Option<Class>; MAX_EIGHTBYTES], Memory> {
-    fn unify(cls: &mut [Class],
-             off: Size,
-             c: Class) {
-        let i = (off.bytes() / 8) as usize;
-        let to_write = match (cls[i], c) {
-            (Class::None, _) => c,
-            (_, Class::None) => return,
-
-            (Class::Int, _) |
-            (_, Class::Int) => Class::Int,
-
-            (Class::Sse, _) |
-            (_, Class::Sse) => Class::Sse,
-
-            (Class::SseUp, Class::SseUp) => Class::SseUp
-        };
-        cls[i] = to_write;
-    }
-
     fn classify<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>,
                           layout: TyLayout<'tcx>,
-                          cls: &mut [Class],
+                          cls: &mut [Option<Class>],
                           off: Size)
                           -> Result<(), Memory> {
         if !off.is_abi_aligned(layout.align) {
@@ -64,31 +47,20 @@ fn classify_arg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, arg: &ArgType<'tcx>)
             return Ok(());
         }
 
-        match layout.abi {
+        let mut c = match layout.abi {
-            layout::Abi::Uninhabited => {}
+            layout::Abi::Uninhabited => return Ok(()),
 
             layout::Abi::Scalar(ref scalar) => {
-                let reg = match scalar.value {
+                match scalar.value {
                     layout::Int(..) |
                     layout::Pointer => Class::Int,
                     layout::F32 |
                     layout::F64 => Class::Sse
-                };
-                unify(cls, off, reg);
-            }
-
-            layout::Abi::Vector { ref element, count } => {
-                unify(cls, off, Class::Sse);
-
-                // everything after the first one is the upper
-                // half of a register.
-                let stride = element.value.size(cx);
-                for i in 1..count {
-                    let field_off = off + stride * i;
-                    unify(cls, field_off, Class::SseUp);
                 }
             }
 
+            layout::Abi::Vector { .. } => Class::Sse,
+
             layout::Abi::ScalarPair(..) |
             layout::Abi::Aggregate { .. } => {
                 match layout.variants {
@@ -97,12 +69,26 @@ fn classify_arg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, arg: &ArgType<'tcx>)
                             let field_off = off + layout.fields.offset(i);
                             classify(cx, layout.field(cx, i), cls, field_off)?;
                         }
+                        return Ok(());
                     }
                     layout::Variants::Tagged { .. } |
                     layout::Variants::NicheFilling { .. } => return Err(Memory),
                 }
             }
 
+        };
+
+        // Fill in `cls` for scalars (Int/Sse) and vectors (Sse).
+        let first = (off.bytes() / 8) as usize;
+        let last = ((off.bytes() + layout.size.bytes() - 1) / 8) as usize;
+        for cls in &mut cls[first..=last] {
+            *cls = Some(cls.map_or(c, |old| old.min(c)));
+
+            // Everything after the first Sse "eightbyte"
+            // component is the upper half of a register.
+            if c == Class::Sse {
+                c = Class::SseUp;
+            }
         }
 
         Ok(())
@@ -113,23 +99,23 @@ fn classify_arg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, arg: &ArgType<'tcx>)
         return Err(Memory);
     }
 
-    let mut cls = [Class::None; MAX_EIGHTBYTES];
+    let mut cls = [None; MAX_EIGHTBYTES];
     classify(cx, arg.layout, &mut cls, Size::from_bytes(0))?;
     if n > 2 {
-        if cls[0] != Class::Sse {
+        if cls[0] != Some(Class::Sse) {
             return Err(Memory);
         }
-        if cls[1..n].iter().any(|&c| c != Class::SseUp) {
+        if cls[1..n].iter().any(|&c| c != Some(Class::SseUp)) {
             return Err(Memory);
         }
     } else {
         let mut i = 0;
         while i < n {
-            if cls[i] == Class::SseUp {
+            if cls[i] == Some(Class::SseUp) {
-                cls[i] = Class::Sse;
+                cls[i] = Some(Class::Sse);
-            } else if cls[i] == Class::Sse {
+            } else if cls[i] == Some(Class::Sse) {
                 i += 1;
-                while i != n && cls[i] == Class::SseUp { i += 1; }
+                while i != n && cls[i] == Some(Class::SseUp) { i += 1; }
             } else {
                 i += 1;
             }
@@ -139,14 +125,14 @@ fn classify_arg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, arg: &ArgType<'tcx>)
     Ok(cls)
 }
 
-fn reg_component(cls: &[Class], i: &mut usize, size: Size) -> Option<Reg> {
+fn reg_component(cls: &[Option<Class>], i: &mut usize, size: Size) -> Option<Reg> {
     if *i >= cls.len() {
         return None;
     }
 
     match cls[*i] {
-        Class::None => None,
+        None => None,
-        Class::Int => {
+        Some(Class::Int) => {
             *i += 1;
             Some(match size.bytes() {
                 1 => Reg::i8(),
@@ -156,8 +142,10 @@ fn reg_component(cls: &[Class], i: &mut usize, size: Size) -> Option<Reg> {
                 _ => Reg::i64()
             })
         }
-        Class::Sse => {
+        Some(Class::Sse) => {
-            let vec_len = 1 + cls[*i+1..].iter().take_while(|&&c| c == Class::SseUp).count();
+            let vec_len = 1 + cls[*i+1..].iter()
+                .take_while(|&&c| c == Some(Class::SseUp))
+                .count();
             *i += vec_len;
             Some(if vec_len == 1 {
                 match size.bytes() {
@@ -171,20 +159,20 @@ fn reg_component(cls: &[Class], i: &mut usize, size: Size) -> Option<Reg> {
                 }
             })
         }
-        c => bug!("reg_component: unhandled class {:?}", c)
+        Some(c) => bug!("reg_component: unhandled class {:?}", c)
     }
 }
 
-fn cast_target(cls: &[Class], size: Size) -> CastTarget {
+fn cast_target(cls: &[Option<Class>], size: Size) -> CastTarget {
     let mut i = 0;
     let lo = reg_component(cls, &mut i, size).unwrap();
     let offset = Size::from_bytes(8) * (i as u64);
-    let target = if size <= offset {
+    let mut target = CastTarget::from(lo);
-        CastTarget::from(lo)
+    if size > offset {
-    } else {
+        if let Some(hi) = reg_component(cls, &mut i, size - offset) {
-        let hi = reg_component(cls, &mut i, size - offset).unwrap();
+            target = CastTarget::Pair(lo, hi);
-        CastTarget::Pair(lo, hi)
+        }
-    };
+    }
     assert_eq!(reg_component(cls, &mut i, Size::from_bytes(0)), None);
     target
 }
@@ -194,44 +182,48 @@ pub fn compute_abi_info<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, fty: &mut FnType<'tc
     let mut sse_regs = 8; // XMM0-7
 
     let mut x86_64_ty = |arg: &mut ArgType<'tcx>, is_arg: bool| {
-        let cls = classify_arg(cx, arg);
+        let mut cls_or_mem = classify_arg(cx, arg);
 
         let mut needed_int = 0;
         let mut needed_sse = 0;
-        let in_mem = match cls {
+        if is_arg {
-            Err(Memory) => true,
+            if let Ok(cls) = cls_or_mem {
-            Ok(ref cls) if is_arg => {
+                for &c in &cls {
-                for &c in cls {
                     match c {
-                        Class::Int => needed_int += 1,
+                        Some(Class::Int) => needed_int += 1,
-                        Class::Sse => needed_sse += 1,
+                        Some(Class::Sse) => needed_sse += 1,
                         _ => {}
                     }
                 }
-                arg.layout.is_aggregate() &&
+                if arg.layout.is_aggregate() {
-                    (int_regs < needed_int || sse_regs < needed_sse)
+                    if int_regs < needed_int || sse_regs < needed_sse {
+                        cls_or_mem = Err(Memory);
+                    }
+                }
             }
-            Ok(_) => false
+        }
-        };
 
-        if in_mem {
+        match cls_or_mem {
-            if is_arg {
+            Err(Memory) => {
-                arg.make_indirect_byval();
+                if is_arg {
-            } else {
+                    arg.make_indirect_byval();
-                // `sret` parameter thus one less integer register available
+                } else {
-                arg.make_indirect();
+                    // `sret` parameter thus one less integer register available
-                int_regs -= 1;
+                    arg.make_indirect();
+                    int_regs -= 1;
+                }
             }
-        } else {
+            Ok(ref cls) => {
-            // split into sized chunks passed individually
+                // split into sized chunks passed individually
-            int_regs -= needed_int;
+                int_regs -= needed_int;
-            sse_regs -= needed_sse;
+                sse_regs -= needed_sse;
 
-            if arg.layout.is_aggregate() {
+                if arg.layout.is_aggregate() {
-                let size = arg.layout.size;
+                    let size = arg.layout.size;
-                arg.cast_to(cast_target(cls.as_ref().unwrap(), size))
+                    arg.cast_to(cast_target(cls, size))
-            } else {
+                } else {
-                arg.extend_integer_width_to(32);
+                    arg.extend_integer_width_to(32);
+                }
             }
         }
     };

src/librustc_trans/debuginfo/mod.rs

@@ -270,6 +270,9 @@ pub fn create_function_debug_context<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>,
         }
         None => {}
     };
+    if sig.output().is_never() {
+        flags = flags | DIFlags::FlagNoReturn;
+    }
 
     let fn_metadata = unsafe {
         llvm::LLVMRustDIBuilderCreateFunction(

src/librustc_trans/mir/mod.rs

@@ -487,16 +487,18 @@ fn arg_local_refs<'a, 'tcx>(bx: &Builder<'a, 'tcx>,
                 // The Rust ABI passes indirect variables using a pointer and a manual copy, so we
                 // need to insert a deref here, but the C ABI uses a pointer and a copy using the
                 // byval attribute, for which LLVM does the deref itself, so we must not add it.
+                // Starting with D31439 in LLVM 5, it *always* does the deref itself.
                 let mut variable_access = VariableAccess::DirectVariable {
                     alloca: place.llval
                 };
-
+                if unsafe { llvm::LLVMRustVersionMajor() < 5 } {
-                if let PassMode::Indirect(ref attrs) = arg.mode {
+                    if let PassMode::Indirect(ref attrs) = arg.mode {
-                    if !attrs.contains(ArgAttribute::ByVal) {
+                        if !attrs.contains(ArgAttribute::ByVal) {
-                        variable_access = VariableAccess::IndirectVariable {
+                            variable_access = VariableAccess::IndirectVariable {
-                            alloca: place.llval,
+                                alloca: place.llval,
-                            address_operations: &deref_op,
+                                address_operations: &deref_op,
-                        };
+                            };
+                        }
                     }
                 }
 

src/librustc_typeck/astconv.rs

@@ -979,7 +979,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                 let item_id = tcx.hir.get_parent_node(node_id);
                 let item_def_id = tcx.hir.local_def_id(item_id);
                 let generics = tcx.generics_of(item_def_id);
-                let index = generics.type_param_to_index[&tcx.hir.local_def_id(node_id).index];
+                let index = generics.type_param_to_index[&tcx.hir.local_def_id(node_id)];
                 tcx.mk_param(index, tcx.hir.name(node_id))
             }
             Def::SelfTy(_, Some(def_id)) => {
@@ -1206,22 +1206,27 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
         let output = bare_fn_ty.output();
         let late_bound_in_ret = tcx.collect_referenced_late_bound_regions(&output);
         for br in late_bound_in_ret.difference(&late_bound_in_args) {
-            let br_name = match *br {
+            let lifetime_name = match *br {
-                ty::BrNamed(_, name) => name,
+                ty::BrNamed(_, name) => format!("lifetime `{}`,", name),
-                _ => {
+                ty::BrAnon(_) | ty::BrFresh(_) | ty::BrEnv => format!("an anonymous lifetime"),
-                    span_bug!(
-                        decl.output.span(),
-                        "anonymous bound region {:?} in return but not args",
-                        br);
-                }
             };
-            struct_span_err!(tcx.sess,
+            let mut err = struct_span_err!(tcx.sess,
-                             decl.output.span(),
+                                           decl.output.span(),
-                             E0581,
+                                           E0581,
-                             "return type references lifetime `{}`, \
+                                           "return type references {} \
-                             which does not appear in the fn input types",
+                                            which is not constrained by the fn input types",
-                             br_name)
+                                           lifetime_name);
-                .emit();
+            if let ty::BrAnon(_) = *br {
+                // The only way for an anonymous lifetime to wind up
+                // in the return type but **also** be unconstrained is
+                // if it only appears in "associated types" in the
+                // input. See #47511 for an example. In this case,
+                // though we can easily give a hint that ought to be
+                // relevant.
+                err.note("lifetimes appearing in an associated type \
+                          are not considered constrained");
+            }
+            err.emit();
         }
 
         bare_fn_ty

src/librustc_typeck/check/cast.rs

@@ -281,10 +281,12 @@ impl<'a, 'gcx, 'tcx> CastCheck<'tcx> {
                                 .emit();
             }
             CastError::SizedUnsizedCast => {
-                type_error_struct!(fcx.tcx.sess, self.span, self.expr_ty, E0607,
+                use structured_errors::{SizedUnsizedCastError, StructuredDiagnostic};
-                                 "cannot cast thin pointer `{}` to fat pointer `{}`",
+                SizedUnsizedCastError::new(&fcx.tcx.sess,
-                                 self.expr_ty,
+                                           self.span,
-                                 fcx.ty_to_string(self.cast_ty)).emit();
+                                           self.expr_ty,
+                                           fcx.ty_to_string(self.cast_ty))
+                    .diagnostic().emit();
             }
             CastError::UnknownCastPtrKind |
             CastError::UnknownExprPtrKind => {

src/librustc_typeck/check/mod.rs

@@ -103,6 +103,7 @@ use rustc::ty::maps::Providers;
 use rustc::ty::util::{Representability, IntTypeExt};
 use rustc::ty::layout::LayoutOf;
 use errors::{DiagnosticBuilder, DiagnosticId};
+
 use require_c_abi_if_variadic;
 use session::{CompileIncomplete, config, Session};
 use TypeAndSubsts;
@@ -1636,7 +1637,7 @@ impl<'a, 'gcx, 'tcx> AstConv<'gcx, 'tcx> for FnCtxt<'a, 'gcx, 'tcx> {
         let item_id = tcx.hir.ty_param_owner(node_id);
         let item_def_id = tcx.hir.local_def_id(item_id);
         let generics = tcx.generics_of(item_def_id);
-        let index = generics.type_param_to_index[&def_id.index];
+        let index = generics.type_param_to_index[&def_id];
         ty::GenericPredicates {
             parent: None,
             predicates: self.param_env.caller_bounds.iter().filter(|predicate| {
@@ -2599,9 +2600,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         // arguments which we skipped above.
         if variadic {
             fn variadic_error<'tcx>(s: &Session, span: Span, t: Ty<'tcx>, cast_ty: &str) {
-                type_error_struct!(s, span, t, E0617,
+                use structured_errors::{VariadicError, StructuredDiagnostic};
-                                   "can't pass `{}` to variadic function, cast to `{}`",
+                VariadicError::new(s, span, t, cast_ty).diagnostic().emit();
-                                   t, cast_ty).emit();
             }
 
             for arg in args.iter().skip(expected_arg_count) {

src/librustc_typeck/collect.rs

@@ -40,8 +40,6 @@ use util::nodemap::FxHashMap;
 
 use rustc_const_math::ConstInt;
 
-use std::collections::BTreeMap;
-
 use syntax::{abi, ast};
 use syntax::codemap::Spanned;
 use syntax::symbol::{Symbol, keywords};
@@ -240,7 +238,7 @@ fn type_param_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     let param_owner = tcx.hir.ty_param_owner(param_id);
     let param_owner_def_id = tcx.hir.local_def_id(param_owner);
     let generics = tcx.generics_of(param_owner_def_id);
-    let index = generics.type_param_to_index[&def_id.index];
+    let index = generics.type_param_to_index[&def_id];
     let ty = tcx.mk_param(index, tcx.hir.ty_param_name(param_id));
 
     // Don't look for bounds where the type parameter isn't in scope.
@@ -1024,10 +1022,9 @@ fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         });
     }
 
-    let mut type_param_to_index = BTreeMap::new();
+    let type_param_to_index = types.iter()
-    for param in &types {
+                                   .map(|param| (param.def_id, param.index))
-        type_param_to_index.insert(param.def_id.index, param.index);
+                                   .collect();
-    }
 
     tcx.alloc_generics(ty::Generics {
         parent: parent_def_id,

src/librustc_typeck/lib.rs

@@ -123,16 +123,17 @@ use std::iter;
 // registered before they are used.
 mod diagnostics;
 
+mod astconv;
 mod check;
 mod check_unused;
-mod astconv;
+mod coherence;
 mod collect;
 mod constrained_type_params;
+mod structured_errors;
 mod impl_wf_check;
-mod coherence;
+mod namespace;
 mod outlives;
 mod variance;
-mod namespace;
 
 pub struct TypeAndSubsts<'tcx> {
     substs: &'tcx Substs<'tcx>,

src/librustc_typeck/structured_errors.rs

@@ -0,0 +1,150 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use rustc::session::Session;
+use syntax_pos::Span;
+use errors::{DiagnosticId, DiagnosticBuilder};
+use rustc::ty::{Ty, TypeFoldable};
+
+pub trait StructuredDiagnostic<'tcx> {
+    fn session(&self) -> &Session;
+
+    fn code(&self) -> DiagnosticId;
+
+    fn common(&self) -> DiagnosticBuilder<'tcx>;
+
+    fn diagnostic(&self) -> DiagnosticBuilder<'tcx> {
+        let err = self.common();
+        if self.session().teach(&self.code()) {
+            self.extended(err)
+        } else {
+            self.regular(err)
+        }
+    }
+
+    fn regular(&self, err: DiagnosticBuilder<'tcx>) -> DiagnosticBuilder<'tcx> {
+        err
+    }
+
+    fn extended(&self, err: DiagnosticBuilder<'tcx>) -> DiagnosticBuilder<'tcx> {
+        err
+    }
+}
+
+pub struct VariadicError<'tcx> {
+    sess: &'tcx Session,
+    span: Span,
+    t: Ty<'tcx>,
+    cast_ty: &'tcx str,
+}
+
+impl<'tcx> VariadicError<'tcx> {
+    pub fn new(sess: &'tcx Session,
+               span: Span,
+               t: Ty<'tcx>,
+               cast_ty: &'tcx str) -> VariadicError<'tcx> {
+        VariadicError { sess, span, t, cast_ty }
+    }
+}
+
+impl<'tcx> StructuredDiagnostic<'tcx> for VariadicError<'tcx> {
+    fn session(&self) -> &Session { self.sess }
+
+    fn code(&self) -> DiagnosticId {
+        __diagnostic_used!(E0617);
+        DiagnosticId::Error("E0617".to_owned())
+    }
+
+    fn common(&self) -> DiagnosticBuilder<'tcx> {
+        let mut err = if self.t.references_error() {
+            self.sess.diagnostic().struct_dummy()
+        } else {
+            self.sess.struct_span_fatal_with_code(
+                self.span,
+                &format!("can't pass `{}` to variadic function", self.t),
+                self.code(),
+            )
+        };
+        if let Ok(snippet) = self.sess.codemap().span_to_snippet(self.span) {
+            err.span_suggestion(self.span,
+                                &format!("cast the value to `{}`", self.cast_ty),
+                                format!("{} as {}", snippet, self.cast_ty));
+        } else {
+            err.help(&format!("cast the value to `{}`", self.cast_ty));
+        }
+        err
+    }
+
+    fn extended(&self, mut err: DiagnosticBuilder<'tcx>) -> DiagnosticBuilder<'tcx> {
+        err.note(&format!("certain types, like `{}`, must be cast before passing them to a \
+                           variadic function, because of arcane ABI rules dictated by the C \
+                           standard",
+                          self.t));
+        err
+    }
+}
+
+pub struct SizedUnsizedCastError<'tcx> {
+    sess: &'tcx Session,
+    span: Span,
+    expr_ty: Ty<'tcx>,
+    cast_ty: String,
+}
+
+impl<'tcx> SizedUnsizedCastError<'tcx> {
+    pub fn new(sess: &'tcx Session,
+               span: Span,
+               expr_ty: Ty<'tcx>,
+               cast_ty: String) -> SizedUnsizedCastError<'tcx> {
+        SizedUnsizedCastError { sess, span, expr_ty, cast_ty }
+    }
+}
+
+impl<'tcx> StructuredDiagnostic<'tcx> for SizedUnsizedCastError<'tcx> {
+    fn session(&self) -> &Session { self.sess }
+
+    fn code(&self) -> DiagnosticId {
+        __diagnostic_used!(E0607);
+        DiagnosticId::Error("E0607".to_owned())
+    }
+
+    fn common(&self) -> DiagnosticBuilder<'tcx> {
+        if self.expr_ty.references_error() {
+            self.sess.diagnostic().struct_dummy()
+        } else {
+            self.sess.struct_span_fatal_with_code(
+                self.span,
+                &format!("cannot cast thin pointer `{}` to fat pointer `{}`",
+                         self.expr_ty,
+                         self.cast_ty),
+                self.code(),
+            )
+        }
+    }
+
+    fn extended(&self, mut err: DiagnosticBuilder<'tcx>) -> DiagnosticBuilder<'tcx> {
+        err.help(
+            "Thin pointers are \"simple\" pointers: they are purely a reference to a
+memory address.
+
+Fat pointers are pointers referencing \"Dynamically Sized Types\" (also
+called DST). DST don't have a statically known size, therefore they can
+only exist behind some kind of pointers that contain additional
+information. Slices and trait objects are DSTs. In the case of slices,
+the additional information the fat pointer holds is their size.
+
+To fix this error, don't try to cast directly between thin and fat
+pointers.
+
+For more information about casts, take a look at The Book:
+https://doc.rust-lang.org/book/first-edition/casting-between-types.html");
+        err
+    }
+}

src/librustc_typeck/variance/constraints.rs

@@ -14,16 +14,12 @@
 //! We walk the set of items and, for each member, generate new constraints.
 
 use hir::def_id::DefId;
-use rustc::dep_graph::{DepGraphSafe, DepKind, DepNodeColor};
-use rustc::ich::StableHashingContext;
 use rustc::ty::subst::Substs;
 use rustc::ty::{self, Ty, TyCtxt};
 use syntax::ast;
 use rustc::hir;
 use rustc::hir::itemlikevisit::ItemLikeVisitor;
 
-use rustc_data_structures::stable_hasher::StableHashingContextProvider;
-
 use super::terms::*;
 use super::terms::VarianceTerm::*;
 
@@ -132,50 +128,11 @@ impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for ConstraintContext<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> StableHashingContextProvider for ConstraintContext<'a, 'tcx> {
-    type ContextType = StableHashingContext<'tcx>;
-
-    fn create_stable_hashing_context(&self) -> Self::ContextType {
-         self.terms_cx.tcx.create_stable_hashing_context()
-    }
-}
-
-impl<'a, 'tcx> DepGraphSafe for ConstraintContext<'a, 'tcx> {}
-
 impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
     fn visit_node_helper(&mut self, id: ast::NodeId) {
         let tcx = self.terms_cx.tcx;
         let def_id = tcx.hir.local_def_id(id);
-
+        self.build_constraints_for_item(def_id);
-        // Encapsulate constructing the constraints into a task we can
-        // reference later. This can go away once the red-green
-        // algorithm is in place.
-        //
-        // See README.md for a detailed discussion
-        // on dep-graph management.
-        let dep_node = def_id.to_dep_node(tcx, DepKind::ItemVarianceConstraints);
-
-        if let Some(DepNodeColor::Green(_)) = tcx.dep_graph.node_color(&dep_node) {
-            // If the corresponding node has already been marked as green, the
-            // appropriate portion of the DepGraph has already been loaded from
-            // the previous graph, so we don't do any dep-tracking. Since we
-            // don't cache any values though, we still have to re-run the
-            // computation.
-            tcx.dep_graph.with_ignore(|| {
-                self.build_constraints_for_item(def_id);
-            });
-        } else {
-            tcx.dep_graph.with_task(dep_node,
-                                    self,
-                                    def_id,
-                                    visit_item_task);
-        }
-
-        fn visit_item_task<'a, 'tcx>(ccx: &mut ConstraintContext<'a, 'tcx>,
-                                     def_id: DefId)
-        {
-            ccx.build_constraints_for_item(def_id);
-        }
     }
 
     fn tcx(&self) -> TyCtxt<'a, 'tcx, 'tcx> {

src/librustc_typeck/variance/mod.rs

@@ -12,7 +12,6 @@
 //! parameters. See README.md for details.
 
 use arena;
-use rustc::dep_graph::DepKind;
 use rustc::hir;
 use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use rustc::ty::{self, CrateVariancesMap, TyCtxt};
@@ -95,9 +94,6 @@ fn variances_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item_def_id: DefId)
     // Everything else must be inferred.
 
     let crate_map = tcx.crate_variances(LOCAL_CRATE);
-    let dep_node = item_def_id.to_dep_node(tcx, DepKind::ItemVarianceConstraints);
-    tcx.dep_graph.read(dep_node);
-
     crate_map.variances.get(&item_def_id)
                        .unwrap_or(&crate_map.empty_variance)
                        .clone()

src/librustdoc/clean/mod.rs

@@ -659,7 +659,8 @@ pub struct Attributes {
     pub other_attrs: Vec<ast::Attribute>,
     pub cfg: Option<Rc<Cfg>>,
     pub span: Option<syntax_pos::Span>,
-    pub links: Vec<(String, DefId)>,
+    /// map from Rust paths to resolved defs and potential URL fragments
+    pub links: Vec<(String, DefId, Option<String>)>,
 }
 
 impl Attributes {
@@ -820,8 +821,12 @@ impl Attributes {
     /// Cache must be populated before call
     pub fn links(&self) -> Vec<(String, String)> {
         use html::format::href;
-        self.links.iter().filter_map(|&(ref s, did)| {
+        self.links.iter().filter_map(|&(ref s, did, ref fragment)| {
-            if let Some((href, ..)) = href(did) {
+            if let Some((mut href, ..)) = href(did) {
+                if let Some(ref fragment) = *fragment {
+                    href.push_str("#");
+                    href.push_str(fragment);
+                }
                 Some((s.clone(), href))
             } else {
                 None
@@ -843,10 +848,8 @@ impl AttributesExt for Attributes {
 /// they exist in both namespaces (structs and modules)
 fn value_ns_kind(def: Def, path_str: &str) -> Option<(&'static str, String)> {
     match def {
-        // structs and mods exist in both namespaces. skip them
+        // structs, variants, and mods exist in both namespaces. skip them
-        Def::StructCtor(..) | Def::Mod(..) => None,
+        Def::StructCtor(..) | Def::Mod(..) | Def::Variant(..) | Def::VariantCtor(..) => None,
-        Def::Variant(..) | Def::VariantCtor(..)
-            => Some(("variant", format!("{}()", path_str))),
         Def::Fn(..)
             => Some(("function", format!("{}()", path_str))),
         Def::Method(..)
@@ -880,10 +883,10 @@ fn ambiguity_error(cx: &DocContext, attrs: &Attributes,
     let sp = attrs.doc_strings.first()
                   .map_or(DUMMY_SP, |a| a.span());
     cx.sess()
-      .struct_span_err(sp,
+      .struct_span_warn(sp,
-                       &format!("`{}` is both {} {} and {} {}",
+                        &format!("`{}` is both {} {} and {} {}",
-                                path_str, article1, kind1,
+                                 path_str, article1, kind1,
-                                article2, kind2))
+                                 article2, kind2))
       .help(&format!("try `{}` if you want to select the {}, \
                       or `{}` if you want to \
                       select the {}",
@@ -892,21 +895,114 @@ fn ambiguity_error(cx: &DocContext, attrs: &Attributes,
              .emit();
 }
 
+/// Given an enum variant's def, return the def of its enum and the associated fragment
+fn handle_variant(cx: &DocContext, def: Def) -> Result<(Def, Option<String>), ()> {
+    use rustc::ty::DefIdTree;
+
+    let parent = if let Some(parent) = cx.tcx.parent(def.def_id()) {
+        parent
+    } else {
+        return Err(())
+    };
+    let parent_def = Def::Enum(parent);
+    let variant = cx.tcx.expect_variant_def(def);
+    Ok((parent_def, Some(format!("{}.v", variant.name))))
+}
+
 /// Resolve a given string as a path, along with whether or not it is
-/// in the value namespace
+/// in the value namespace. Also returns an optional URL fragment in the case
-fn resolve(cx: &DocContext, path_str: &str, is_val: bool) -> Result<hir::Path, ()> {
+/// of variants and methods
+fn resolve(cx: &DocContext, path_str: &str, is_val: bool) -> Result<(Def, Option<String>), ()> {
     // In case we're in a module, try to resolve the relative
     // path
     if let Some(id) = cx.mod_ids.borrow().last() {
-        cx.resolver.borrow_mut()
+        let result = cx.resolver.borrow_mut()
-                   .with_scope(*id, |resolver| {
+                                .with_scope(*id,
-                        resolver.resolve_str_path_error(DUMMY_SP,
+            |resolver| {
-                                                        &path_str, is_val)
+                resolver.resolve_str_path_error(DUMMY_SP,
-                    })
+                                                &path_str, is_val)
+        });
+
+        if let Ok(result) = result {
+            // In case this is a trait item, skip the
+            // early return and try looking for the trait
+            let value = match result.def {
+                Def::Method(_) | Def::AssociatedConst(_) => true,
+                Def::AssociatedTy(_)  => false,
+                Def::Variant(_) => return handle_variant(cx, result.def),
+                // not a trait item, just return what we found
+                _ => return Ok((result.def, None))
+            };
+
+            if value != is_val {
+                return Err(())
+            }
+        } else {
+            // If resolution failed, it may still be a method
+            // because methods are not handled by the resolver
+            // If so, bail when we're not looking for a value
+            if !is_val {
+                return Err(())
+            }
+        }
+
+        // Try looking for methods and associated items
+        let mut split = path_str.rsplitn(2, "::");
+        let mut item_name = if let Some(first) = split.next() {
+            first
+        } else {
+            return Err(())
+        };
+
+        let mut path = if let Some(second) = split.next() {
+            second
+        } else {
+            return Err(())
+        };
+
+        let ty = cx.resolver.borrow_mut()
+                            .with_scope(*id,
+            |resolver| {
+                resolver.resolve_str_path_error(DUMMY_SP,
+                                                &path, false)
+        })?;
+        match ty.def {
+            Def::Struct(did) | Def::Union(did) | Def::Enum(did) | Def::TyAlias(did) => {
+                let item = cx.tcx.inherent_impls(did).iter()
+                                 .flat_map(|imp| cx.tcx.associated_items(*imp))
+                                 .find(|item| item.name == item_name);
+                if let Some(item) = item {
+                    if item.kind == ty::AssociatedKind::Method && is_val {
+                        Ok((ty.def, Some(format!("method.{}", item_name))))
+                    } else {
+                        Err(())
+                    }
+                } else {
+                    Err(())
+                }
+            }
+            Def::Trait(did) => {
+                let item = cx.tcx.associated_item_def_ids(did).iter()
+                             .map(|item| cx.tcx.associated_item(*item))
+                             .find(|item| item.name == item_name);
+                if let Some(item) = item {
+                    let kind = match item.kind {
+                        ty::AssociatedKind::Const if is_val => "associatedconstant",
+                        ty::AssociatedKind::Type if !is_val => "associatedtype",
+                        ty::AssociatedKind::Method if is_val => "tymethod",
+                        _ => return Err(())
+                    };
+
+                    Ok((ty.def, Some(format!("{}.{}", kind, item_name))))
+                } else {
+                    Err(())
+                }
+            }
+            _ => Err(())
+        }
+
     } else {
-        // FIXME(Manishearth) this branch doesn't seem to ever be hit, really
+        Err(())
-        cx.resolver.borrow_mut()
-                   .resolve_str_path_error(DUMMY_SP, &path_str, is_val)
     }
 }
 
@@ -955,7 +1051,7 @@ impl Clean<Attributes> for [ast::Attribute] {
         if UnstableFeatures::from_environment().is_nightly_build() {
             let dox = attrs.collapsed_doc_value().unwrap_or_else(String::new);
             for link in markdown_links(&dox, cx.render_type) {
-                let def = {
+                let (def, fragment)  = {
                     let mut kind = PathKind::Unknown;
                     let path_str = if let Some(prefix) =
                         ["struct@", "enum@", "type@",
@@ -965,7 +1061,8 @@ impl Clean<Attributes> for [ast::Attribute] {
                         link.trim_left_matches(prefix)
                     } else if let Some(prefix) =
                         ["const@", "static@",
-                         "value@", "function@", "mod@", "fn@", "module@"]
+                         "value@", "function@", "mod@",
+                         "fn@", "module@", "method@"]
                             .iter().find(|p| link.starts_with(**p)) {
                         kind = PathKind::Value;
                         link.trim_left_matches(prefix)
@@ -993,8 +1090,8 @@ impl Clean<Attributes> for [ast::Attribute] {
 
                     match kind {
                         PathKind::Value => {
-                            if let Ok(path) = resolve(cx, path_str, true) {
+                            if let Ok(def) = resolve(cx, path_str, true) {
-                                path.def
+                                def
                             } else {
                                 // this could just be a normal link or a broken link
                                 // we could potentially check if something is
@@ -1003,8 +1100,8 @@ impl Clean<Attributes> for [ast::Attribute] {
                             }
                         }
                         PathKind::Type => {
-                            if let Ok(path) = resolve(cx, path_str, false) {
+                            if let Ok(def) = resolve(cx, path_str, false) {
-                                path.def
+                                def
                             } else {
                                 // this could just be a normal link
                                 continue;
@@ -1013,42 +1110,42 @@ impl Clean<Attributes> for [ast::Attribute] {
                         PathKind::Unknown => {
                             // try everything!
                             if let Some(macro_def) = macro_resolve(cx, path_str) {
-                                if let Ok(type_path) = resolve(cx, path_str, false) {
+                                if let Ok(type_def) = resolve(cx, path_str, false) {
                                     let (type_kind, article, type_disambig)
-                                        = type_ns_kind(type_path.def, path_str);
+                                        = type_ns_kind(type_def.0, path_str);
                                     ambiguity_error(cx, &attrs, path_str,
                                                     article, type_kind, &type_disambig,
                                                     "a", "macro", &format!("macro@{}", path_str));
                                     continue;
-                                } else if let Ok(value_path) = resolve(cx, path_str, true) {
+                                } else if let Ok(value_def) = resolve(cx, path_str, true) {
                                     let (value_kind, value_disambig)
-                                        = value_ns_kind(value_path.def, path_str)
+                                        = value_ns_kind(value_def.0, path_str)
                                             .expect("struct and mod cases should have been \
                                                      caught in previous branch");
                                     ambiguity_error(cx, &attrs, path_str,
                                                     "a", value_kind, &value_disambig,
                                                     "a", "macro", &format!("macro@{}", path_str));
                                 }
-                                macro_def
+                                (macro_def, None)
-                            } else if let Ok(type_path) = resolve(cx, path_str, false) {
+                            } else if let Ok(type_def) = resolve(cx, path_str, false) {
                                 // It is imperative we search for not-a-value first
                                 // Otherwise we will find struct ctors for when we are looking
                                 // for structs, and the link won't work.
                                 // if there is something in both namespaces
-                                if let Ok(value_path) = resolve(cx, path_str, true) {
+                                if let Ok(value_def) = resolve(cx, path_str, true) {
-                                    let kind = value_ns_kind(value_path.def, path_str);
+                                    let kind = value_ns_kind(value_def.0, path_str);
                                     if let Some((value_kind, value_disambig)) = kind {
                                         let (type_kind, article, type_disambig)
-                                            = type_ns_kind(type_path.def, path_str);
+                                            = type_ns_kind(type_def.0, path_str);
                                         ambiguity_error(cx, &attrs, path_str,
                                                         article, type_kind, &type_disambig,
                                                         "a", value_kind, &value_disambig);
                                         continue;
                                     }
                                 }
-                                type_path.def
+                                type_def
-                            } else if let Ok(value_path) = resolve(cx, path_str, true) {
+                            } else if let Ok(value_def) = resolve(cx, path_str, true) {
-                                value_path.def
+                                value_def
                             } else {
                                 // this could just be a normal link
                                 continue;
@@ -1056,7 +1153,7 @@ impl Clean<Attributes> for [ast::Attribute] {
                         }
                         PathKind::Macro => {
                             if let Some(def) = macro_resolve(cx, path_str) {
-                                def
+                                (def, None)
                             } else {
                                 continue
                             }
@@ -1066,7 +1163,7 @@ impl Clean<Attributes> for [ast::Attribute] {
 
 
                 let id = register_def(cx, def);
-                attrs.links.push((link, id));
+                attrs.links.push((link, id, fragment));
             }
 
             cx.sess().abort_if_errors();

src/librustdoc/html/render.rs

@@ -1243,6 +1243,16 @@ impl DocFolder for Cache {
             _ => self.stripped_mod,
         };
 
+        // If the impl is from a masked crate or references something from a
+        // masked crate then remove it completely.
+        if let clean::ImplItem(ref i) = item.inner {
+            if self.masked_crates.contains(&item.def_id.krate) ||
+               i.trait_.def_id().map_or(false, |d| self.masked_crates.contains(&d.krate)) ||
+               i.for_.def_id().map_or(false, |d| self.masked_crates.contains(&d.krate)) {
+                return None;
+            }
+        }
+
         // Register any generics to their corresponding string. This is used
         // when pretty-printing types.
         if let Some(generics) = item.inner.generics() {
@@ -1257,14 +1267,10 @@ impl DocFolder for Cache {
 
         // Collect all the implementors of traits.
         if let clean::ImplItem(ref i) = item.inner {
-            if !self.masked_crates.contains(&item.def_id.krate) {
+            if let Some(did) = i.trait_.def_id() {
-                if let Some(did) = i.trait_.def_id() {
+                self.implementors.entry(did).or_insert(vec![]).push(Impl {
-                    if i.for_.def_id().map_or(true, |d| !self.masked_crates.contains(&d.krate)) {
+                    impl_item: item.clone(),
-                        self.implementors.entry(did).or_insert(vec![]).push(Impl {
+                });
-                            impl_item: item.clone(),
-                        });
-                    }
-                }
             }
         }
 
@@ -1427,24 +1433,20 @@ impl DocFolder for Cache {
                 // Note: matching twice to restrict the lifetime of the `i` borrow.
                 let mut dids = FxHashSet();
                 if let clean::Item { inner: clean::ImplItem(ref i), .. } = item {
-                    let masked_trait = i.trait_.def_id().map_or(false,
+                    match i.for_ {
-                        |d| self.masked_crates.contains(&d.krate));
+                        clean::ResolvedPath { did, .. } |
-                    if !masked_trait {
+                        clean::BorrowedRef {
-                        match i.for_ {
+                            type_: box clean::ResolvedPath { did, .. }, ..
-                            clean::ResolvedPath { did, .. } |
+                        } => {
-                            clean::BorrowedRef {
+                            dids.insert(did);
-                                type_: box clean::ResolvedPath { did, .. }, ..
+                        }
-                            } => {
+                        ref t => {
-                                dids.insert(did);
+                            let did = t.primitive_type().and_then(|t| {
-                            }
+                                self.primitive_locations.get(&t).cloned()
-                            ref t => {
+                            });
-                                let did = t.primitive_type().and_then(|t| {
-                                    self.primitive_locations.get(&t).cloned()
-                                });
 
-                                if let Some(did) = did {
+                            if let Some(did) = did {
-                                    dids.insert(did);
+                                dids.insert(did);
-                                }
                             }
                         }
                     }

src/libsyntax/ast.rs

@@ -33,6 +33,18 @@ use std::fmt;
 use std::rc::Rc;
 use std::u32;
 
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
+pub struct Label {
+    pub ident: Ident,
+    pub span: Span,
+}
+
+impl fmt::Debug for Label {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "label({:?})", self.ident)
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
@@ -1078,23 +1090,23 @@ pub enum ExprKind {
     /// A while loop, with an optional label
     ///
     /// `'label: while expr { block }`
-    While(P<Expr>, P<Block>, Option<SpannedIdent>),
+    While(P<Expr>, P<Block>, Option<Label>),
     /// A while-let loop, with an optional label
     ///
     /// `'label: while let pat = expr { block }`
     ///
     /// This is desugared to a combination of `loop` and `match` expressions.
-    WhileLet(P<Pat>, P<Expr>, P<Block>, Option<SpannedIdent>),
+    WhileLet(P<Pat>, P<Expr>, P<Block>, Option<Label>),
     /// A for loop, with an optional label
     ///
     /// `'label: for pat in expr { block }`
     ///
     /// This is desugared to a combination of `loop` and `match` expressions.
-    ForLoop(P<Pat>, P<Expr>, P<Block>, Option<SpannedIdent>),
+    ForLoop(P<Pat>, P<Expr>, P<Block>, Option<Label>),
     /// Conditionless loop (can be exited with break, continue, or return)
     ///
     /// `'label: loop { block }`
-    Loop(P<Block>, Option<SpannedIdent>),
+    Loop(P<Block>, Option<Label>),
     /// A `match` block.
     Match(P<Expr>, Vec<Arm>),
     /// A closure (for example, `move |a, b, c| a + b + c`)
@@ -1133,9 +1145,9 @@ pub enum ExprKind {
     /// A referencing operation (`&a` or `&mut a`)
     AddrOf(Mutability, P<Expr>),
     /// A `break`, with an optional label to break, and an optional expression
-    Break(Option<SpannedIdent>, Option<P<Expr>>),
+    Break(Option<Label>, Option<P<Expr>>),
     /// A `continue`, with an optional label
-    Continue(Option<SpannedIdent>),
+    Continue(Option<Label>),
     /// A `return`, with an optional value to be returned
     Ret(Option<P<Expr>>),
 

src/libsyntax/ext/base.rs

@@ -786,7 +786,7 @@ impl<'a> ExtCtxt<'a> {
     ///   substitute; we never hit resolve/type-checking so the dummy
     ///   value doesn't have to match anything)
     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
-        panic!(self.parse_sess.span_diagnostic.span_fatal(sp, msg));
+        self.parse_sess.span_diagnostic.span_fatal(sp, msg).raise();
     }
 
     /// Emit `msg` attached to `sp`, without immediately stopping

src/libsyntax/ext/expand.rs

@@ -455,7 +455,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 suggested_limit));
             err.emit();
             self.cx.trace_macros_diag();
-            panic!(FatalError);
+            FatalError.raise();
         }
 
         Some(result)

src/libsyntax/ext/source_util.rs

@@ -116,9 +116,10 @@ pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[tokenstream::T
             while self.p.token != token::Eof {
                 match panictry!(self.p.parse_item()) {
                     Some(item) => ret.push(item),
-                    None => panic!(self.p.diagnostic().span_fatal(self.p.span,
+                    None => self.p.diagnostic().span_fatal(self.p.span,
                                                            &format!("expected item, found `{}`",
-                                                                    self.p.this_token_to_string())))
+                                                                    self.p.this_token_to_string()))
+                                               .raise()
                 }
             }
             Some(ret)

src/libsyntax/ext/tt/macro_parser.rs

@@ -573,7 +573,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
             Some(i) => token::NtItem(i),
             None => {
                 p.fatal("expected an item keyword").emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         },
         "block" => token::NtBlock(panictry!(p.parse_block())),
@@ -581,7 +581,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
             Some(s) => token::NtStmt(s),
             None => {
                 p.fatal("expected a statement").emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         },
         "pat" => token::NtPat(panictry!(p.parse_pat())),
@@ -597,7 +597,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
                 let token_str = pprust::token_to_string(&p.token);
                 p.fatal(&format!("expected ident, found {}",
                                  &token_str[..])).emit();
-                panic!(FatalError)
+                FatalError.raise()
             }
         },
         "path" => token::NtPath(panictry!(p.parse_path_common(PathStyle::Type, false))),

src/libsyntax/ext/tt/macro_rules.rs

@@ -222,10 +222,10 @@ pub fn compile(sess: &ParseSess, features: &RefCell<Features>, def: &ast::Item)
         Success(m) => m,
         Failure(sp, tok) => {
             let s = parse_failure_msg(tok);
-            panic!(sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s));
+            sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
         }
         Error(sp, s) => {
-            panic!(sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s));
+            sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
         }
     };
 

src/libsyntax/feature_gate.rs

@@ -1954,7 +1954,7 @@ impl FeatureChecker {
                 .span_note(ca_span, "`#![feature(custom_attribute)]` declared here")
                 .emit();
 
-            panic!(FatalError);
+            FatalError.raise();
         }
 
         if let (Some(span), None) = (self.copy_closures, self.clone_closures) {
@@ -1963,7 +1963,7 @@ impl FeatureChecker {
                   .span_note(span, "`#![feature(copy_closures)]` declared here")
                   .emit();
 
-            panic!(FatalError);
+            FatalError.raise();
         }
     }
 }

src/libsyntax/fold.rs

@@ -193,6 +193,10 @@ pub trait Folder : Sized {
         noop_fold_macro_def(def, self)
     }
 
+    fn fold_label(&mut self, label: Label) -> Label {
+        noop_fold_label(label, self)
+    }
+
     fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
         noop_fold_lifetime(l, self)
     }
@@ -696,6 +700,13 @@ pub fn noop_fold_generic_params<T: Folder>(
     params.move_map(|p| fld.fold_generic_param(p))
 }
 
+pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
+    Label {
+        ident: fld.fold_ident(label.ident),
+        span: fld.new_span(label.span),
+    }
+}
+
 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
     Lifetime {
         id: fld.new_id(l.id),
@@ -1206,30 +1217,26 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mu
                           folder.fold_block(tr),
                           fl.map(|x| folder.fold_expr(x)))
             }
-            ExprKind::While(cond, body, opt_ident) => {
+            ExprKind::While(cond, body, opt_label) => {
                 ExprKind::While(folder.fold_expr(cond),
                           folder.fold_block(body),
-                          opt_ident.map(|label| respan(folder.new_span(label.span),
+                          opt_label.map(|label| folder.fold_label(label)))
-                                                       folder.fold_ident(label.node))))
             }
-            ExprKind::WhileLet(pat, expr, body, opt_ident) => {
+            ExprKind::WhileLet(pat, expr, body, opt_label) => {
                 ExprKind::WhileLet(folder.fold_pat(pat),
                              folder.fold_expr(expr),
                              folder.fold_block(body),
-                             opt_ident.map(|label| respan(folder.new_span(label.span),
+                             opt_label.map(|label| folder.fold_label(label)))
-                                                          folder.fold_ident(label.node))))
             }
-            ExprKind::ForLoop(pat, iter, body, opt_ident) => {
+            ExprKind::ForLoop(pat, iter, body, opt_label) => {
                 ExprKind::ForLoop(folder.fold_pat(pat),
                             folder.fold_expr(iter),
                             folder.fold_block(body),
-                            opt_ident.map(|label| respan(folder.new_span(label.span),
+                            opt_label.map(|label| folder.fold_label(label)))
-                                                         folder.fold_ident(label.node))))
             }
-            ExprKind::Loop(body, opt_ident) => {
+            ExprKind::Loop(body, opt_label) => {
                 ExprKind::Loop(folder.fold_block(body),
-                               opt_ident.map(|label| respan(folder.new_span(label.span),
+                               opt_label.map(|label| folder.fold_label(label)))
-                                                            folder.fold_ident(label.node))))
             }
             ExprKind::Match(expr, arms) => {
                 ExprKind::Match(folder.fold_expr(expr),
@@ -1278,15 +1285,13 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mu
                 });
                 ExprKind::Path(qself, folder.fold_path(path))
             }
-            ExprKind::Break(opt_ident, opt_expr) => {
+            ExprKind::Break(opt_label, opt_expr) => {
-                ExprKind::Break(opt_ident.map(|label| respan(folder.new_span(label.span),
+                ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
-                                                             folder.fold_ident(label.node))),
                                 opt_expr.map(|e| folder.fold_expr(e)))
             }
-            ExprKind::Continue(opt_ident) => ExprKind::Continue(opt_ident.map(|label|
+            ExprKind::Continue(opt_label) => {
-                respan(folder.new_span(label.span),
+                ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
-                       folder.fold_ident(label.node)))
+            }
-            ),
             ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
             ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
                 InlineAsm {

src/libsyntax/lib.rs

@@ -54,7 +54,7 @@ macro_rules! panictry {
             Ok(e) => e,
             Err(mut e) => {
                 e.emit();
-                panic!(FatalError);
+                FatalError.raise()
             }
         }
     })

src/libsyntax/parse/lexer/comments.rs

@@ -265,7 +265,7 @@ fn read_block_comment(rdr: &mut StringReader,
         while level > 0 {
             debug!("=== block comment level {}", level);
             if rdr.is_eof() {
-                panic!(rdr.fatal("unterminated block comment"));
+                rdr.fatal("unterminated block comment").raise();
             }
             if rdr.ch_is('\n') {
                 trim_whitespace_prefix_and_push_line(&mut lines, curr_line, col);

src/libsyntax/parse/lexer/mod.rs

@@ -90,7 +90,7 @@ impl<'a> StringReader<'a> {
             Ok(tok) => tok,
             Err(_) => {
                 self.emit_fatal_errors();
-                panic!(FatalError);
+                FatalError.raise();
             }
         }
     }
@@ -191,7 +191,7 @@ impl<'a> StringReader<'a> {
         let mut sr = StringReader::new_raw(sess, filemap);
         if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
-            panic!(FatalError);
+            FatalError.raise();
         }
         sr
     }
@@ -216,7 +216,7 @@ impl<'a> StringReader<'a> {
 
         if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
-            panic!(FatalError);
+            FatalError.raise();
         }
         sr
     }
@@ -647,7 +647,7 @@ impl<'a> StringReader<'a> {
                     "unterminated block comment"
                 };
                 let last_bpos = self.pos;
-                panic!(self.fatal_span_(start_bpos, last_bpos, msg));
+                self.fatal_span_(start_bpos, last_bpos, msg).raise();
             }
             let n = self.ch.unwrap();
             match n {
@@ -808,9 +808,9 @@ impl<'a> StringReader<'a> {
         for _ in 0..n_digits {
             if self.is_eof() {
                 let last_bpos = self.pos;
-                panic!(self.fatal_span_(start_bpos,
+                self.fatal_span_(start_bpos,
-                                        last_bpos,
+                                 last_bpos,
-                                        "unterminated numeric character escape"));
+                                 "unterminated numeric character escape").raise();
             }
             if self.ch_is(delim) {
                 let last_bpos = self.pos;
@@ -1025,9 +1025,9 @@ impl<'a> StringReader<'a> {
                     }
                 },
                 None => {
-                    panic!(self.fatal_span_(start_bpos,
+                    self.fatal_span_(start_bpos,
-                                            self.pos,
+                                     self.pos,
-                                            "unterminated unicode escape (found EOF)"));
+                                     "unterminated unicode escape (found EOF)").raise();
                 }
             }
             self.bump();
@@ -1283,9 +1283,9 @@ impl<'a> StringReader<'a> {
                     // lifetimes shouldn't end with a single quote
                     // if we find one, then this is an invalid character literal
                     if self.ch_is('\'') {
-                        panic!(self.fatal_span_verbose(
+                        self.fatal_span_verbose(start_with_quote, self.next_pos,
-                               start_with_quote, self.next_pos,
+                                String::from("character literal may only contain one codepoint"))
-                               String::from("character literal may only contain one codepoint")));
+                            .raise();
 
                     }
 
@@ -1332,9 +1332,8 @@ impl<'a> StringReader<'a> {
                             break;
                         }
                     }
-                    panic!(self.fatal_span_verbose(
+                    self.fatal_span_verbose(start_with_quote, pos,
-                           start_with_quote, pos,
+                        String::from("character literal may only contain one codepoint")).raise();
-                           String::from("character literal may only contain one codepoint")));
                 }
 
                 let id = if valid {
@@ -1364,9 +1363,9 @@ impl<'a> StringReader<'a> {
                 while !self.ch_is('"') {
                     if self.is_eof() {
                         let last_bpos = self.pos;
-                        panic!(self.fatal_span_(start_bpos,
+                        self.fatal_span_(start_bpos,
-                                                last_bpos,
+                                         last_bpos,
-                                                "unterminated double quote string"));
+                                         "unterminated double quote string").raise();
                     }
 
                     let ch_start = self.pos;
@@ -1399,15 +1398,15 @@ impl<'a> StringReader<'a> {
 
                 if self.is_eof() {
                     let last_bpos = self.pos;
-                    panic!(self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"));
+                    self.fatal_span_(start_bpos, last_bpos, "unterminated raw string").raise();
                 } else if !self.ch_is('"') {
                     let last_bpos = self.pos;
                     let curr_char = self.ch.unwrap();
-                    panic!(self.fatal_span_char(start_bpos,
+                    self.fatal_span_char(start_bpos,
-                                                last_bpos,
+                                         last_bpos,
-                                                "found invalid character; only `#` is allowed \
+                                         "found invalid character; only `#` is allowed \
-                                                 in raw string delimitation",
+                                         in raw string delimitation",
-                                                curr_char));
+                                         curr_char).raise();
                 }
                 self.bump();
                 let content_start_bpos = self.pos;
@@ -1416,7 +1415,7 @@ impl<'a> StringReader<'a> {
                 'outer: loop {
                     if self.is_eof() {
                         let last_bpos = self.pos;
-                        panic!(self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"));
+                        self.fatal_span_(start_bpos, last_bpos, "unterminated raw string").raise();
                     }
                     // if self.ch_is('"') {
                     // content_end_bpos = self.pos;
@@ -1573,9 +1572,9 @@ impl<'a> StringReader<'a> {
             // character before position `start` are an
             // ascii single quote and ascii 'b'.
             let pos = self.pos;
-            panic!(self.fatal_span_verbose(start - BytePos(2),
+            self.fatal_span_verbose(start - BytePos(2),
-                                           pos,
+                                    pos,
-                                           "unterminated byte constant".to_string()));
+                                    "unterminated byte constant".to_string()).raise();
         }
 
         let id = if valid {
@@ -1599,7 +1598,7 @@ impl<'a> StringReader<'a> {
         while !self.ch_is('"') {
             if self.is_eof() {
                 let pos = self.pos;
-                panic!(self.fatal_span_(start, pos, "unterminated double quote byte string"));
+                self.fatal_span_(start, pos, "unterminated double quote byte string").raise();
             }
 
             let ch_start = self.pos;
@@ -1631,15 +1630,15 @@ impl<'a> StringReader<'a> {
 
         if self.is_eof() {
             let pos = self.pos;
-            panic!(self.fatal_span_(start_bpos, pos, "unterminated raw string"));
+            self.fatal_span_(start_bpos, pos, "unterminated raw string").raise();
         } else if !self.ch_is('"') {
             let pos = self.pos;
             let ch = self.ch.unwrap();
-            panic!(self.fatal_span_char(start_bpos,
+            self.fatal_span_char(start_bpos,
                                         pos,
                                         "found invalid character; only `#` is allowed in raw \
                                          string delimitation",
-                                        ch));
+                                        ch).raise();
         }
         self.bump();
         let content_start_bpos = self.pos;
@@ -1648,7 +1647,7 @@ impl<'a> StringReader<'a> {
             match self.ch {
                 None => {
                     let pos = self.pos;
-                    panic!(self.fatal_span_(start_bpos, pos, "unterminated raw string"))
+                    self.fatal_span_(start_bpos, pos, "unterminated raw string").raise()
                 }
                 Some('"') => {
                     content_end_bpos = self.pos;

src/libsyntax/parse/mod.rs

@@ -212,8 +212,8 @@ fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
         Err(e) => {
             let msg = format!("couldn't read {:?}: {}", path.display(), e);
             match spanopt {
-                Some(sp) => panic!(sess.span_diagnostic.span_fatal(sp, &msg)),
+                Some(sp) => sess.span_diagnostic.span_fatal(sp, &msg).raise(),
-                None => panic!(sess.span_diagnostic.fatal(&msg))
+                None => sess.span_diagnostic.fatal(&msg).raise()
             }
         }
     }

src/libsyntax/parse/parser.rs

@@ -23,7 +23,7 @@ use ast::{Field, FnDecl};
 use ast::{ForeignItem, ForeignItemKind, FunctionRetTy};
 use ast::GenericParam;
 use ast::{Ident, ImplItem, IsAuto, Item, ItemKind};
-use ast::{Lifetime, LifetimeDef, Lit, LitKind, UintTy};
+use ast::{Label, Lifetime, LifetimeDef, Lit, LitKind, UintTy};
 use ast::Local;
 use ast::MacStmtStyle;
 use ast::Mac_;
@@ -1325,15 +1325,17 @@ impl<'a> Parser<'a> {
             self.check_keyword(keywords::Extern)
     }
 
-    fn get_label(&mut self) -> ast::Ident {
+    fn eat_label(&mut self) -> Option<Label> {
-        match self.token {
+        let ident = match self.token {
             token::Lifetime(ref ident) => *ident,
             token::Interpolated(ref nt) => match nt.0 {
                 token::NtLifetime(lifetime) => lifetime.ident,
-                _ => self.bug("not a lifetime"),
+                _ => return None,
             },
-            _ => self.bug("not a lifetime"),
+            _ => return None,
-        }
+        };
+        self.bump();
+        Some(Label { ident, span: self.prev_span })
     }
 
     /// parse a TyKind::BareFn type:
@@ -2317,11 +2319,8 @@ impl<'a> Parser<'a> {
                     let lo = self.prev_span;
                     return self.parse_while_expr(None, lo, attrs);
                 }
-                if self.token.is_lifetime() {
+                if let Some(label) = self.eat_label() {
-                    let label = Spanned { node: self.get_label(),
+                    let lo = label.span;
-                                          span: self.span };
-                    let lo = self.span;
-                    self.bump();
                     self.expect(&token::Colon)?;
                     if self.eat_keyword(keywords::While) {
                         return self.parse_while_expr(Some(label), lo, attrs)
@@ -2339,16 +2338,8 @@ impl<'a> Parser<'a> {
                     return self.parse_loop_expr(None, lo, attrs);
                 }
                 if self.eat_keyword(keywords::Continue) {
-                    let ex = if self.token.is_lifetime() {
+                    let label = self.eat_label();
-                        let ex = ExprKind::Continue(Some(Spanned{
+                    let ex = ExprKind::Continue(label);
-                            node: self.get_label(),
-                            span: self.span
-                        }));
-                        self.bump();
-                        ex
-                    } else {
-                        ExprKind::Continue(None)
-                    };
                     let hi = self.prev_span;
                     return Ok(self.mk_expr(lo.to(hi), ex, attrs));
                 }
@@ -2376,16 +2367,7 @@ impl<'a> Parser<'a> {
                         ex = ExprKind::Ret(None);
                     }
                 } else if self.eat_keyword(keywords::Break) {
-                    let lt = if self.token.is_lifetime() {
+                    let label = self.eat_label();
-                        let spanned_lt = Spanned {
-                            node: self.get_label(),
-                            span: self.span
-                        };
-                        self.bump();
-                        Some(spanned_lt)
-                    } else {
-                        None
-                    };
                     let e = if self.token.can_begin_expr()
                                && !(self.token == token::OpenDelim(token::Brace)
                                     && self.restrictions.contains(
@@ -2394,7 +2376,7 @@ impl<'a> Parser<'a> {
                     } else {
                         None
                     };
-                    ex = ExprKind::Break(lt, e);
+                    ex = ExprKind::Break(label, e);
                     hi = self.prev_span;
                 } else if self.eat_keyword(keywords::Yield) {
                     if self.token.can_begin_expr() {
@@ -3291,7 +3273,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a 'for' .. 'in' expression ('for' token already eaten)
-    pub fn parse_for_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_for_expr(&mut self, opt_label: Option<Label>,
                           span_lo: Span,
                           mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         // Parse: `for <src_pat> in <src_expr> <src_loop_block>`
@@ -3309,25 +3291,25 @@ impl<'a> Parser<'a> {
         attrs.extend(iattrs);
 
         let hi = self.prev_span;
-        Ok(self.mk_expr(span_lo.to(hi), ExprKind::ForLoop(pat, expr, loop_block, opt_ident), attrs))
+        Ok(self.mk_expr(span_lo.to(hi), ExprKind::ForLoop(pat, expr, loop_block, opt_label), attrs))
     }
 
     /// Parse a 'while' or 'while let' expression ('while' token already eaten)
-    pub fn parse_while_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_while_expr(&mut self, opt_label: Option<Label>,
                             span_lo: Span,
                             mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         if self.token.is_keyword(keywords::Let) {
-            return self.parse_while_let_expr(opt_ident, span_lo, attrs);
+            return self.parse_while_let_expr(opt_label, span_lo, attrs);
         }
         let cond = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?;
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        return Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_ident), attrs));
+        return Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_label), attrs));
     }
 
     /// Parse a 'while let' expression ('while' token already eaten)
-    pub fn parse_while_let_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_while_let_expr(&mut self, opt_label: Option<Label>,
                                 span_lo: Span,
                                 mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         self.expect_keyword(keywords::Let)?;
@@ -3337,17 +3319,17 @@ impl<'a> Parser<'a> {
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        return Ok(self.mk_expr(span, ExprKind::WhileLet(pat, expr, body, opt_ident), attrs));
+        return Ok(self.mk_expr(span, ExprKind::WhileLet(pat, expr, body, opt_label), attrs));
     }
 
     // parse `loop {...}`, `loop` token already eaten
-    pub fn parse_loop_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_loop_expr(&mut self, opt_label: Option<Label>,
                            span_lo: Span,
                            mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        Ok(self.mk_expr(span, ExprKind::Loop(body, opt_ident), attrs))
+        Ok(self.mk_expr(span, ExprKind::Loop(body, opt_label), attrs))
     }
 
     /// Parse a `do catch {...}` expression (`do catch` token already eaten)

src/libsyntax/print/pprust.rs

@@ -2104,9 +2104,9 @@ impl<'a> State<'a> {
             ast::ExprKind::IfLet(ref pat, ref expr, ref blk, ref elseopt) => {
                 self.print_if_let(pat, expr, blk, elseopt.as_ref().map(|e| &**e))?;
             }
-            ast::ExprKind::While(ref test, ref blk, opt_ident) => {
+            ast::ExprKind::While(ref test, ref blk, opt_label) => {
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("while")?;
@@ -2114,9 +2114,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::WhileLet(ref pat, ref expr, ref blk, opt_ident) => {
+            ast::ExprKind::WhileLet(ref pat, ref expr, ref blk, opt_label) => {
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("while let")?;
@@ -2127,9 +2127,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_ident) => {
+            ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_label) => {
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("for")?;
@@ -2140,9 +2140,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::Loop(ref blk, opt_ident) => {
+            ast::ExprKind::Loop(ref blk, opt_label) => {
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("loop")?;
@@ -2238,11 +2238,11 @@ impl<'a> State<'a> {
             ast::ExprKind::Path(Some(ref qself), ref path) => {
                 self.print_qpath(path, qself, true)?
             }
-            ast::ExprKind::Break(opt_ident, ref opt_expr) => {
+            ast::ExprKind::Break(opt_label, ref opt_expr) => {
                 self.s.word("break")?;
                 self.s.space()?;
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.s.space()?;
                 }
                 if let Some(ref expr) = *opt_expr {
@@ -2250,11 +2250,11 @@ impl<'a> State<'a> {
                     self.s.space()?;
                 }
             }
-            ast::ExprKind::Continue(opt_ident) => {
+            ast::ExprKind::Continue(opt_label) => {
                 self.s.word("continue")?;
                 self.s.space()?;
-                if let Some(ident) = opt_ident {
+                if let Some(label) = opt_label {
-                    self.print_ident(ident.node)?;
+                    self.print_ident(label.ident)?;
                     self.s.space()?
                 }
             }

src/libsyntax/test.rs

@@ -123,7 +123,7 @@ impl<'a> fold::Folder for TestHarnessGenerator<'a> {
             match i.node {
                 ast::ItemKind::Fn(_, ast::Unsafety::Unsafe, _, _, _, _) => {
                     let diag = self.cx.span_diagnostic;
-                    panic!(diag.span_fatal(i.span, "unsafe functions cannot be used for tests"));
+                    diag.span_fatal(i.span, "unsafe functions cannot be used for tests").raise();
                 }
                 _ => {
                     debug!("this is a test function");

src/libsyntax/visit.rs

@@ -101,6 +101,9 @@ pub trait Visitor<'ast>: Sized {
     fn visit_variant(&mut self, v: &'ast Variant, g: &'ast Generics, item_id: NodeId) {
         walk_variant(self, v, g, item_id)
     }
+    fn visit_label(&mut self, label: &'ast Label) {
+        walk_label(self, label)
+    }
     fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
         walk_lifetime(self, lifetime)
     }
@@ -163,25 +166,6 @@ macro_rules! walk_list {
     }
 }
 
-pub fn walk_opt_name<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
-    if let Some(name) = opt_name {
-        visitor.visit_name(span, name);
-    }
-}
-
-pub fn walk_opt_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
-    if let Some(ident) = opt_ident {
-        visitor.visit_ident(span, ident);
-    }
-}
-
-pub fn walk_opt_sp_ident<'a, V: Visitor<'a>>(visitor: &mut V,
-                                             opt_sp_ident: &Option<Spanned<Ident>>) {
-    if let Some(ref sp_ident) = *opt_sp_ident {
-        visitor.visit_ident(sp_ident.span, sp_ident.node);
-    }
-}
-
 pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, ident: Ident) {
     visitor.visit_name(span, ident.name);
 }
@@ -204,6 +188,10 @@ pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
     walk_list!(visitor, visit_expr, &local.init);
 }
 
+pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
+    visitor.visit_ident(label.span, label.ident);
+}
+
 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
     visitor.visit_ident(lifetime.span, lifetime.ident);
 }
@@ -226,7 +214,9 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
     visitor.visit_ident(item.span, item.ident);
     match item.node {
         ItemKind::ExternCrate(opt_name) => {
-            walk_opt_name(visitor, item.span, opt_name)
+            if let Some(name) = opt_name {
+                visitor.visit_name(item.span, name);
+            }
         }
         ItemKind::Use(ref use_tree) => {
             visitor.visit_use_tree(use_tree, item.id, false)
@@ -622,7 +612,9 @@ pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &
 
 pub fn walk_struct_field<'a, V: Visitor<'a>>(visitor: &mut V, struct_field: &'a StructField) {
     visitor.visit_vis(&struct_field.vis);
-    walk_opt_ident(visitor, struct_field.span, struct_field.ident);
+    if let Some(ident) = struct_field.ident {
+        visitor.visit_ident(struct_field.span, ident);
+    }
     visitor.visit_ty(&struct_field.ty);
     walk_list!(visitor, visit_attribute, &struct_field.attrs);
 }
@@ -708,10 +700,10 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_block(if_block);
             walk_list!(visitor, visit_expr, optional_else);
         }
-        ExprKind::While(ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::While(ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
         ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
             visitor.visit_pat(pattern);
@@ -719,21 +711,21 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_block(if_block);
             walk_list!(visitor, visit_expr, optional_else);
         }
-        ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_pat(pattern);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
-        ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_pat(pattern);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
-        ExprKind::Loop(ref block, ref opt_sp_ident) => {
+        ExprKind::Loop(ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
         ExprKind::Match(ref subexpression, ref arms) => {
             visitor.visit_expr(subexpression);
@@ -775,12 +767,12 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             }
             visitor.visit_path(path, expression.id)
         }
-        ExprKind::Break(ref opt_sp_ident, ref opt_expr) => {
+        ExprKind::Break(ref opt_label, ref opt_expr) => {
-            walk_opt_sp_ident(visitor, opt_sp_ident);
+            walk_list!(visitor, visit_label, opt_label);
             walk_list!(visitor, visit_expr, opt_expr);
         }
-        ExprKind::Continue(ref opt_sp_ident) => {
+        ExprKind::Continue(ref opt_label) => {
-            walk_opt_sp_ident(visitor, opt_sp_ident);
+            walk_list!(visitor, visit_label, opt_label);
         }
         ExprKind::Ret(ref optional_expression) => {
             walk_list!(visitor, visit_expr, optional_expression);

src/libsyntax_ext/deriving/custom.rs

@@ -92,7 +92,7 @@ impl MultiItemModifier for ProcMacroDerive {
                 }
 
                 err.emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         };
 
@@ -103,13 +103,13 @@ impl MultiItemModifier for ProcMacroDerive {
                 // fail if there have been errors emitted
                 Ok(_) if ecx.parse_sess.span_diagnostic.err_count() > error_count_before => {
                     ecx.struct_span_fatal(span, msg).emit();
-                    panic!(FatalError);
+                    FatalError.raise();
                 }
                 Ok(new_items) => new_items.into_iter().map(Annotatable::Item).collect(),
                 Err(_) => {
                     // FIXME: handle this better
                     ecx.struct_span_fatal(span, msg).emit();
-                    panic!(FatalError);
+                    FatalError.raise();
                 }
             }
         })

src/libsyntax_ext/proc_macro_impl.rs

@@ -51,7 +51,7 @@ impl base::AttrProcMacro for AttrProcMacro {
                 }
 
                 err.emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         }
     }
@@ -86,7 +86,7 @@ impl base::ProcMacro for BangProcMacro {
                 }
 
                 err.emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         }
     }

src/llvm

@@ -1 +1 @@
-Subproject commit 2717444753318e461e0c3b30dacd03ffbac96903
+Subproject commit bc344d5bc23c61ff9baf82d268a0edf199933cc3

src/rustllvm/ArchiveWrapper.cpp

@@ -42,7 +42,6 @@ struct RustArchiveIterator {
 enum class LLVMRustArchiveKind {
   Other,
   GNU,
-  MIPS64,
   BSD,
   COFF,
 };
@@ -51,8 +50,6 @@ static Archive::Kind fromRust(LLVMRustArchiveKind Kind) {
   switch (Kind) {
   case LLVMRustArchiveKind::GNU:
     return Archive::K_GNU;
-  case LLVMRustArchiveKind::MIPS64:
-    return Archive::K_MIPS64;
   case LLVMRustArchiveKind::BSD:
     return Archive::K_BSD;
   case LLVMRustArchiveKind::COFF:
@@ -235,9 +232,16 @@ LLVMRustWriteArchive(char *Dst, size_t NumMembers,
       Members.push_back(std::move(*MOrErr));
     }
   }
-  auto Pair = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
+  auto Result = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
-  if (!Pair.second)
+#if LLVM_VERSION_GE(6, 0)
+  if (!Result)
     return LLVMRustResult::Success;
-  LLVMRustSetLastError(Pair.second.message().c_str());
+  LLVMRustSetLastError(toString(std::move(Result)).c_str());
+#else
+  if (!Result.second)
+    return LLVMRustResult::Success;
+  LLVMRustSetLastError(Result.second.message().c_str());
+#endif
+
   return LLVMRustResult::Failure;
 }

src/rustllvm/PassWrapper.cpp

@@ -23,9 +23,15 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 
+#if LLVM_VERSION_GE(6, 0)
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/IR/IntrinsicInst.h"
+#else
+#include "llvm/Target/TargetSubtargetInfo.h"
+#endif
+
 #if LLVM_VERSION_GE(4, 0)
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
@@ -210,20 +216,15 @@ extern "C" bool LLVMRustHasFeature(LLVMTargetMachineRef TM,
 
 enum class LLVMRustCodeModel {
   Other,
-  Default,
-  JITDefault,
   Small,
   Kernel,
   Medium,
   Large,
+  None,
 };
 
 static CodeModel::Model fromRust(LLVMRustCodeModel Model) {
   switch (Model) {
-  case LLVMRustCodeModel::Default:
-    return CodeModel::Default;
-  case LLVMRustCodeModel::JITDefault:
-    return CodeModel::JITDefault;
   case LLVMRustCodeModel::Small:
     return CodeModel::Small;
   case LLVMRustCodeModel::Kernel:
@@ -360,7 +361,6 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     bool TrapUnreachable,
     bool Singlethread) {
 
-  auto CM = fromRust(RustCM);
   auto OptLevel = fromRust(RustOptLevel);
   auto RM = fromRust(RustReloc);
 
@@ -399,6 +399,13 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     Options.ThreadModel = ThreadModel::Single;
   }
 
+#if LLVM_VERSION_GE(6, 0)
+  Optional<CodeModel::Model> CM;
+#else
+  CodeModel::Model CM = CodeModel::Model::Default;
+#endif
+  if (RustCM != LLVMRustCodeModel::None)
+    CM = fromRust(RustCM);
   TargetMachine *TM = TheTarget->createTargetMachine(
       Trip.getTriple(), RealCPU, Feature, Options, RM, CM, OptLevel);
   return wrap(TM);

src/rustllvm/RustWrapper.cpp

@@ -315,7 +315,11 @@ extern "C" void LLVMRustRemoveFunctionAttributes(LLVMValueRef Fn,
 // enable fpmath flag UnsafeAlgebra
 extern "C" void LLVMRustSetHasUnsafeAlgebra(LLVMValueRef V) {
   if (auto I = dyn_cast<Instruction>(unwrap<Value>(V))) {
+#if LLVM_VERSION_GE(6, 0)
+    I->setFast(true);
+#else
     I->setHasUnsafeAlgebra(true);
+#endif
   }
 }
 
@@ -457,9 +461,13 @@ enum class LLVMRustDIFlags : uint32_t {
   FlagStaticMember = (1 << 12),
   FlagLValueReference = (1 << 13),
   FlagRValueReference = (1 << 14),
-  FlagMainSubprogram      = (1 << 21),
+  FlagExternalTypeRef = (1 << 15),
+  FlagIntroducedVirtual = (1 << 18),
+  FlagBitField = (1 << 19),
+  FlagNoReturn = (1 << 20),
+  FlagMainSubprogram = (1 << 21),
   // Do not add values that are not supported by the minimum LLVM
-  // version we support!
+  // version we support! see llvm/include/llvm/IR/DebugInfoFlags.def
 };
 
 inline LLVMRustDIFlags operator&(LLVMRustDIFlags A, LLVMRustDIFlags B) {
@@ -544,7 +552,19 @@ static unsigned fromRust(LLVMRustDIFlags Flags) {
   if (isSet(Flags & LLVMRustDIFlags::FlagRValueReference)) {
     Result |= DINode::DIFlags::FlagRValueReference;
   }
+  if (isSet(Flags & LLVMRustDIFlags::FlagExternalTypeRef)) {
+    Result |= DINode::DIFlags::FlagExternalTypeRef;
+  }
+  if (isSet(Flags & LLVMRustDIFlags::FlagIntroducedVirtual)) {
+    Result |= DINode::DIFlags::FlagIntroducedVirtual;
+  }
+  if (isSet(Flags & LLVMRustDIFlags::FlagBitField)) {
+    Result |= DINode::DIFlags::FlagBitField;
+  }
 #if LLVM_RUSTLLVM || LLVM_VERSION_GE(4, 0)
+  if (isSet(Flags & LLVMRustDIFlags::FlagNoReturn)) {
+    Result |= DINode::DIFlags::FlagNoReturn;
+  }
   if (isSet(Flags & LLVMRustDIFlags::FlagMainSubprogram)) {
     Result |= DINode::DIFlags::FlagMainSubprogram;
   }

src/rustllvm/llvm-rebuild-trigger

@@ -1,4 +1,4 @@
 # If this file is modified, then llvm will be (optionally) cleaned and then rebuilt.
 # The actual contents of this file do not matter, but to trigger a change on the
 # build bots then the contents should be changed so git updates the mtime.
-2017-11-08
+2018-01-25

src/test/codegen/noreturnflag.rs

@@ -0,0 +1,24 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+// min-llvm-version 4.0
+
+// compile-flags: -g -C no-prepopulate-passes
+
+// CHECK: {{.*}}DISubprogram{{.*}}name: "foo"{{.*}}DIFlagNoReturn
+
+fn foo() -> ! {
+    loop {}
+}
+
+pub fn main() {
+    foo();
+}

src/test/codegen/x86_mmx.rs

@@ -22,9 +22,7 @@ pub struct i8x8(u64);
 
 #[no_mangle]
 pub fn a(a: &mut i8x8, b: i8x8) -> i8x8 {
-    // CHECK-LABEL: define x86_mmx @a(x86_mmx*{{.*}}, x86_mmx{{.*}})
+    // CHECK-LABEL: define void @a(x86_mmx*{{.*}}, x86_mmx*{{.*}}, x86_mmx*{{.*}})
-    // CHECK: store x86_mmx %b, x86_mmx* %a
-    // CHECK: ret x86_mmx %b
     *a = b;
     return b
 }

src/test/compile-fail/E0617.rs

@@ -17,16 +17,22 @@ extern {
 fn main() {
     unsafe {
         printf(::std::ptr::null(), 0f32);
-        //~^ ERROR can't pass `f32` to variadic function, cast to `c_double` [E0617]
+        //~^ ERROR can't pass `f32` to variadic function
+        //~| HELP cast the value to `c_double`
         printf(::std::ptr::null(), 0i8);
-        //~^ ERROR can't pass `i8` to variadic function, cast to `c_int` [E0617]
+        //~^ ERROR can't pass `i8` to variadic function
+        //~| HELP cast the value to `c_int`
         printf(::std::ptr::null(), 0i16);
-        //~^ ERROR can't pass `i16` to variadic function, cast to `c_int` [E0617]
+        //~^ ERROR can't pass `i16` to variadic function
+        //~| HELP cast the value to `c_int`
         printf(::std::ptr::null(), 0u8);
-        //~^ ERROR can't pass `u8` to variadic function, cast to `c_uint` [E0617]
+        //~^ ERROR can't pass `u8` to variadic function
+        //~| HELP cast the value to `c_uint`
         printf(::std::ptr::null(), 0u16);
-        //~^ ERROR can't pass `u16` to variadic function, cast to `c_uint` [E0617]
+        //~^ ERROR can't pass `u16` to variadic function
+        //~| HELP cast the value to `c_uint`
         printf(::std::ptr::null(), printf);
-        //~^ ERROR can't pass `unsafe extern "C" fn(*const i8, ...) {printf}` to variadic function, cast to `unsafe extern "C" fn(*const i8, ...)` [E0617]
+        //~^ ERROR can't pass `unsafe extern "C" fn(*const i8, ...) {printf}` to variadic function
+        //~| HELP cast the value to `unsafe extern "C" fn(*const i8, ...)`
     }
 }

src/test/compile-fail/dep-graph-variance-alias.rs

@@ -23,7 +23,7 @@ struct Foo<T> {
     f: T
 }
 
-#[rustc_if_this_changed]
+#[rustc_if_this_changed(Krate)]
 type TypeAlias<T> = Foo<T>;
 
 #[rustc_then_this_would_need(ItemVariances)] //~ ERROR OK

src/test/compile-fail/empty-never-array.rs

@@ -0,0 +1,27 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(never_type)]
+
+enum Helper<T, U> {
+    T(T, [!; 0]),
+    #[allow(dead_code)]
+    U(U),
+}
+
+fn transmute<T, U>(t: T) -> U {
+    let Helper::U(u) = Helper::T(t, []);
+    //~^ ERROR refutable pattern in local binding: `T(_, _)` not covered
+    u
+}
+
+fn main() {
+    println!("{:?}", transmute::<&str, (*const u8, u64)>("type safety"));
+}

src/test/compile-fail/impl-trait/infinite-impl-trait-issue-38064.rs

@@ -0,0 +1,39 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that attempts to construct infinite types via impl trait fail
+// in a graceful way.
+//
+// Regression test for #38064.
+
+// error-pattern:overflow evaluating the requirement `impl Quux`
+
+#![feature(conservative_impl_trait)]
+
+trait Quux {}
+
+fn foo() -> impl Quux {
+    struct Foo<T>(T);
+    impl<T> Quux for Foo<T> {}
+    Foo(bar())
+}
+
+fn bar() -> impl Quux {
+    struct Bar<T>(T);
+    impl<T> Quux for Bar<T> {}
+    Bar(foo())
+}
+
+// effectively:
+//     struct Foo(Bar);
+//     struct Bar(Foo);
+// should produce an error about infinite size
+
+fn main() { foo(); }

src/test/compile-fail/issue-32201.rs

@@ -17,6 +17,7 @@ fn bar(_: *const u8) {}
 fn main() {
     unsafe {
         foo(0, bar);
-        //~^ ERROR can't pass `fn(*const u8) {bar}` to variadic function, cast to `fn(*const u8)`
+        //~^ ERROR can't pass `fn(*const u8) {bar}` to variadic function
+        //~| HELP cast the value to `fn(*const u8)`
     }
 }

src/test/compile-fail/panic-runtime/runtime-depend-on-needs-runtime.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 // aux-build:needs-panic-runtime.rs
-// aux-build:runtime-depending-on-panic-runtime.rs
+// aux-build:depends.rs
 // error-pattern:cannot depend on a crate that needs a panic runtime
 
-extern crate runtime_depending_on_panic_runtime;
+extern crate depends;

src/test/run-make/codegen-options-parsing/Makefile

@@ -16,11 +16,11 @@ all:
 	$(RUSTC) -C extra-filename=foo dummy.rs 2>&1
 	#Option taking no argument
 	$(RUSTC) -C lto= dummy.rs 2>&1 | \
-		$(CGREP) 'codegen option `lto` takes no value'
+		$(CGREP) 'codegen option `lto` - one of `thin`, `fat`, or'
 	$(RUSTC) -C lto=1 dummy.rs 2>&1 | \
-		$(CGREP) 'codegen option `lto` takes no value'
+		$(CGREP) 'codegen option `lto` - one of `thin`, `fat`, or'
 	$(RUSTC) -C lto=foo dummy.rs 2>&1 | \
-		$(CGREP) 'codegen option `lto` takes no value'
+		$(CGREP) 'codegen option `lto` - one of `thin`, `fat`, or'
 	$(RUSTC) -C lto dummy.rs
 
 	# Should not link dead code...

src/test/run-make/no-integrated-as/Makefile

@@ -0,0 +1,7 @@
+-include ../tools.mk
+
+all:
+ifeq ($(TARGET),x86_64-unknown-linux-gnu)
+	$(RUSTC) hello.rs -C no_integrated_as
+	$(call RUN,hello)
+endif

src/test/run-make/no-integrated-as/hello.rs

@@ -0,0 +1,13 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    println!("Hello, world!");
+}

src/test/run-pass/align-with-extern-c-fn.rs

@@ -14,10 +14,10 @@
 #![feature(attr_literals)]
 
 #[repr(align(16))]
-pub struct A {
+pub struct A(i64);
-    y: i64,
-}
 
 pub extern "C" fn foo(x: A) {}
 
-fn main() {}
+fn main() {
+    foo(A(0));
+}

src/test/run-pass/conditional-compile-arch.rs

@@ -28,6 +28,9 @@ pub fn main() { }
 #[cfg(target_arch = "mips64")]
 pub fn main() { }
 
+#[cfg(target_arch = "powerpc")]
+pub fn main() { }
+
 #[cfg(target_arch = "powerpc64")]
 pub fn main() { }
 

src/test/run-pass/fat-lto.rs

@@ -0,0 +1,17 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: -Clto=fat
+// no-prefer-dynamic
+
+fn main() {
+    println!("hello!");
+}
+

src/test/run-pass/intrinsic-alignment.rs

@@ -19,7 +19,8 @@ mod rusti {
     }
 }
 
-#[cfg(any(target_os = "cloudabi",
+#[cfg(any(target_os = "android",
+          target_os = "cloudabi",
           target_os = "dragonfly",
           target_os = "emscripten",
           target_os = "freebsd",
@@ -80,15 +81,3 @@ mod m {
         }
     }
 }
-
-#[cfg(target_os = "android")]
-mod m {
-    #[main]
-    #[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
-    pub fn main() {
-        unsafe {
-            assert_eq!(::rusti::pref_align_of::<u64>(), 8);
-            assert_eq!(::rusti::min_align_of::<u64>(), 8);
-        }
-    }
-}

src/test/run-pass/issue-38763.rs

@@ -0,0 +1,23 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-emscripten
+
+#![feature(i128_type)]
+
+#[repr(C)]
+pub struct Foo(i128);
+
+#[no_mangle]
+pub extern "C" fn foo(x: Foo) -> Foo { x }
+
+fn main() {
+    foo(Foo(1));
+}