Auto merge of #59012 - pietroalbini:rollup, r=pietroalbini

Rollup of 24 pull requests

Successful merges:

 - #58080 (Add FreeBSD armv6 and armv7 targets)
 - #58204 (On return type `impl Trait` for block with no expr point at last semi)
 - #58269 (Add librustc and libsyntax to rust-src distribution.)
 - #58369 (Make the Entry API of HashMap<K, V> Sync and Send)
 - #58861 (Expand where negative supertrait specific error is shown)
 - #58877 (Suggest removal of `&` when borrowing macro and appropriate)
 - #58883 (Suggest appropriate code for unused field when destructuring pattern)
 - #58891 (Remove stray ` in the docs for the FromIterator implementation for Option)
 - #58893 (race condition in thread local storage example)
 - #58906 (Monomorphize generator field types for debuginfo)
 - #58911 (Regression test for #58435.)
 - #58912 (Regression test for #58813)
 - #58916 (Fix release note problems noticed after merging.)
 - #58918 (Regression test added for an async ICE.)
 - #58921 (Add an explicit test for issue #50582)
 - #58926 (Make the lifetime parameters of tcx consistent.)
 - #58931 (Elide invalid method receiver error when it contains TyErr)
 - #58940 (Remove JSBackend from config.toml)
 - #58950 (Add self to mailmap)
 - #58961 (On incorrect cfg literal/identifier, point at the right span)
 - #58963 (libstd: implement Error::source for io::Error)
 - #58970 (delay_span_bug in wfcheck's ty.lift_to_tcx unwrap)
 - #58984 (Teach `-Z treat-err-as-bug` to take a number of errors to emit)
 - #59007 (Add a test for invalid const arguments)

Failed merges:

 - #58959 (Add release notes for PR #56243)

r? @ghost

.mailmap

@@ -161,6 +161,7 @@ Michael Woerister <michaelwoerister@posteo> <michaelwoerister@gmail>
 Mickaël Raybaud-Roig <raybaudroigm@gmail.com> m-r-r <raybaudroigm@gmail.com>
 Ms2ger <ms2ger@gmail.com> <Ms2ger@gmail.com>
 Mukilan Thiagarajan <mukilanthiagarajan@gmail.com>
+Nathan West <Lucretiel@gmail.com> <lucretiel@gmail.com>
 Nathan Wilson <wilnathan@gmail.com>
 Nathaniel Herman <nherman@post.harvard.edu> Nathaniel Herman <nherman@college.harvard.edu>
 Neil Pankey <npankey@gmail.com> <neil@wire.im>

RELEASES.md

@@ -4,10 +4,10 @@ Version 1.33.0 (2019-02-28)
 Language
 --------
 - [You can now use the `cfg(target_vendor)` attribute.][57465] E.g.
-  `#[cfg(target_vendor="linux")] fn main() { println!("Hello Linux!"); }`
+  `#[cfg(target_vendor="apple")] fn main() { println!("Hello Apple!"); }`
 - [Integer patterns such as in a match expression can now be exhaustive.][56362]
   E.g. You can have match statement on a `u8` that covers `0..=255` and
-  you would no longer be required to have a `_ => unreachable!()` case. 
+  you would no longer be required to have a `_ => unreachable!()` case.
 - [You can now have multiple patterns in `if let` and `while let`
   expressions.][57532] You can do this with the same syntax as a `match`
   expression. E.g.
@@ -51,8 +51,7 @@ Language
   // Allowed as there is only one `Read` in the module.
   pub trait Read {}
   ```
-- [`extern` functions will now abort by default when panicking.][55982]
+- [You may now use `Rc`, `Arc`, and `Pin` as method receivers][56805].
-  This was previously undefined behaviour.
 
 Compiler
 --------
@@ -109,27 +108,30 @@ Compatibility Notes
   are now deprecated in the standard library, and their usage will now produce a warning.
   Please use the `str::{trim_start, trim_end, trim_start_matches, trim_end_matches}`
   methods instead.
+- The `Error::cause` method has been deprecated in favor of `Error::source` which supports
+  downcasting.
 
-[57615]: https://github.com/rust-lang/rust/pull/57615/
+[55982]: https://github.com/rust-lang/rust/pull/55982/
-[57465]: https://github.com/rust-lang/rust/pull/57465/
+[56303]: https://github.com/rust-lang/rust/pull/56303/
-[57532]: https://github.com/rust-lang/rust/pull/57532/
+[56351]: https://github.com/rust-lang/rust/pull/56351/
-[57535]: https://github.com/rust-lang/rust/pull/57535/
+[56362]: https://github.com/rust-lang/rust/pull/56362
-[57566]: https://github.com/rust-lang/rust/pull/57566/
+[56642]: https://github.com/rust-lang/rust/pull/56642/
+[56769]: https://github.com/rust-lang/rust/pull/56769/
+[56805]: https://github.com/rust-lang/rust/pull/56805
+[56947]: https://github.com/rust-lang/rust/pull/56947/
+[57049]: https://github.com/rust-lang/rust/pull/57049/
+[57067]: https://github.com/rust-lang/rust/pull/57067/
+[57105]: https://github.com/rust-lang/rust/pull/57105
 [57130]: https://github.com/rust-lang/rust/pull/57130/
 [57167]: https://github.com/rust-lang/rust/pull/57167/
 [57175]: https://github.com/rust-lang/rust/pull/57175/
 [57234]: https://github.com/rust-lang/rust/pull/57234/
 [57332]: https://github.com/rust-lang/rust/pull/57332/
-[56947]: https://github.com/rust-lang/rust/pull/56947/
+[57465]: https://github.com/rust-lang/rust/pull/57465/
-[57049]: https://github.com/rust-lang/rust/pull/57049/
+[57532]: https://github.com/rust-lang/rust/pull/57532/
-[57067]: https://github.com/rust-lang/rust/pull/57067/
+[57535]: https://github.com/rust-lang/rust/pull/57535/
-[56769]: https://github.com/rust-lang/rust/pull/56769/
+[57566]: https://github.com/rust-lang/rust/pull/57566/
-[56642]: https://github.com/rust-lang/rust/pull/56642/
+[57615]: https://github.com/rust-lang/rust/pull/57615/
-[56303]: https://github.com/rust-lang/rust/pull/56303/
-[56351]: https://github.com/rust-lang/rust/pull/56351/
-[55982]: https://github.com/rust-lang/rust/pull/55982/
-[56362]: https://github.com/rust-lang/rust/pull/56362
-[57105]: https://github.com/rust-lang/rust/pull/57105
 [cargo/6484]: https://github.com/rust-lang/cargo/pull/6484/
 [`unix::FileExt::read_exact_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.read_exact_at
 [`unix::FileExt::write_all_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.write_all_at
@@ -170,7 +172,7 @@ Language
 - [You can now match against literals in macros with the `literal`
   specifier.][56072] This will match against a literal of any type.
   E.g. `1`, `'A'`, `"Hello World"`
-- [Self can now be used as a constructor and pattern for unit and tuple structs.][56365] E.g. 
+- [Self can now be used as a constructor and pattern for unit and tuple structs.][56365] E.g.
   ```rust
   struct Point(i32, i32);
 
@@ -460,7 +462,7 @@ Version 1.31.0 (2018-12-06)
 
 Language
 --------
-- 🎉 [This version marks the release of the 2018 edition of Rust.][54057] 🎉 
+- 🎉 [This version marks the release of the 2018 edition of Rust.][54057] 🎉
 - [New lifetime elision rules now allow for eliding lifetimes in functions and
   impl headers.][54778] E.g. `impl<'a> Reader for BufReader<'a> {}` can now be
   `impl Reader for BufReader<'_> {}`. Lifetimes are still required to be defined

config.toml.example

@@ -61,7 +61,7 @@
 # support. You'll need to write a target specification at least, and most
 # likely, teach rustc about the C ABI of the target. Get in touch with the
 # Rust team and file an issue if you need assistance in porting!
-#targets = "X86;ARM;AArch64;Mips;PowerPC;SystemZ;JSBackend;MSP430;Sparc;NVPTX;Hexagon"
+#targets = "X86;ARM;AArch64;Mips;PowerPC;SystemZ;MSP430;Sparc;NVPTX;Hexagon"
 
 # LLVM experimental targets to build support for. These targets are specified in
 # the same format as above, but since these targets are experimental, they are

src/bootstrap/bootstrap.py

@@ -262,6 +262,10 @@ def default_build_triple():
         cputype = 'arm'
         if ostype == 'linux-android':
             ostype = 'linux-androideabi'
+        elif ostype == 'unknown-freebsd':
+            cputype = subprocess.check_output(
+                ['uname', '-p']).strip().decode(default_encoding)
+            ostype = 'unknown-freebsd'
     elif cputype == 'armv6l':
         cputype = 'arm'
         if ostype == 'linux-android':

src/bootstrap/dist.rs

@@ -904,6 +904,8 @@ impl Step for Src {
             "src/stdsimd",
             "src/libproc_macro",
             "src/tools/rustc-std-workspace-core",
+            "src/librustc",
+            "src/libsyntax",
         ];
 
         copy_src_dirs(builder, &std_src_dirs[..], &[], &dst_src);

src/libcore/option.rs

@@ -1286,7 +1286,7 @@ impl<A, V: FromIterator<A>> FromIterator<Option<A>> for Option<V> {
     /// # Examples
     ///
     /// Here is an example which increments every integer in a vector.
-    /// `We use the checked variant of `add` that returns `None` when the
+    /// We use the checked variant of `add` that returns `None` when the
     /// calculation would result in an overflow.
     ///
     /// ```

src/librustc/middle/liveness.rs

@@ -379,9 +379,22 @@ fn visit_fn<'a, 'tcx: 'a>(ir: &mut IrMaps<'a, 'tcx>,
     let body = ir.tcx.hir().body(body_id);
 
     for arg in &body.arguments {
+        let is_shorthand = match arg.pat.node {
+            crate::hir::PatKind::Struct(..) => true,
+            _ => false,
+        };
         arg.pat.each_binding(|_bm, hir_id, _x, ident| {
             debug!("adding argument {:?}", hir_id);
-            fn_maps.add_variable(Arg(hir_id, ident.name));
+            let var = if is_shorthand {
+                Local(LocalInfo {
+                    id: hir_id,
+                    name: ident.name,
+                    is_shorthand: true,
+                })
+            } else {
+                Arg(hir_id, ident.name)
+            };
+            fn_maps.add_variable(var);
         })
     };
 

src/librustc/session/config.rs

@@ -816,6 +816,8 @@ macro_rules! options {
             Some("crate=integer");
         pub const parse_unpretty: Option<&str> =
             Some("`string` or `string=string`");
+        pub const parse_treat_err_as_bug: Option<&str> =
+            Some("either no value or a number bigger than 0");
         pub const parse_lto: Option<&str> =
             Some("either a boolean (`yes`, `no`, `on`, `off`, etc), `thin`, \
                   `fat`, or omitted");
@@ -1022,6 +1024,13 @@ macro_rules! options {
             }
         }
 
+        fn parse_treat_err_as_bug(slot: &mut Option<usize>, v: Option<&str>) -> bool {
+            match v {
+                Some(s) => { *slot = s.parse().ok().filter(|&x| x != 0); slot.unwrap_or(0) != 0 }
+                None => { *slot = Some(1); true }
+            }
+        }
+
         fn parse_lto(slot: &mut LtoCli, v: Option<&str>) -> bool {
             if v.is_some() {
                 let mut bool_arg = None;
@@ -1236,8 +1245,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "load proc macros for both target and host, but only link to the target"),
     no_codegen: bool = (false, parse_bool, [TRACKED],
         "run all passes except codegen; no output"),
-    treat_err_as_bug: bool = (false, parse_bool, [TRACKED],
+    treat_err_as_bug: Option<usize> = (None, parse_treat_err_as_bug, [TRACKED],
-        "treat all errors that occur as bugs"),
+        "treat error number `val` that occurs as bug"),
     report_delayed_bugs: bool = (false, parse_bool, [TRACKED],
         "immediately print bugs registered with `delay_span_bug`"),
     external_macro_backtrace: bool = (false, parse_bool, [UNTRACKED],
@@ -3214,7 +3223,7 @@ mod tests {
         assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());
 
         opts = reference.clone();
-        opts.debugging_opts.treat_err_as_bug = true;
+        opts.debugging_opts.treat_err_as_bug = Some(1);
         assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());
 
         opts = reference.clone();

src/librustc/session/mod.rs

@@ -1315,7 +1315,7 @@ pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
             Box::new(EmitterWriter::stderr(color_config, None, true, false))
         }
     };
-    let handler = errors::Handler::with_emitter(true, false, emitter);
+    let handler = errors::Handler::with_emitter(true, None, emitter);
     handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
     errors::FatalError.raise();
 }
@@ -1330,7 +1330,7 @@ pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
             Box::new(EmitterWriter::stderr(color_config, None, true, false))
         }
     };
-    let handler = errors::Handler::with_emitter(true, false, emitter);
+    let handler = errors::Handler::with_emitter(true, None, emitter);
     handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
 }
 

src/librustc/traits/error_reporting.rs

@@ -599,11 +599,12 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
-    pub fn report_selection_error(&self,
+    pub fn report_selection_error(
-                                  obligation: &PredicateObligation<'tcx>,
+        &self,
-                                  error: &SelectionError<'tcx>,
+        obligation: &PredicateObligation<'tcx>,
-                                  fallback_has_occurred: bool)
+        error: &SelectionError<'tcx>,
-    {
+        fallback_has_occurred: bool,
+    ) {
         let span = obligation.cause.span;
 
         let mut err = match *error {
@@ -673,6 +674,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
                         self.suggest_borrow_on_unsized_slice(&obligation.cause.code, &mut err);
                         self.suggest_remove_reference(&obligation, &mut err, &trait_ref);
+                        self.suggest_semicolon_removal(&obligation, &mut err, span, &trait_ref);
 
                         // Try to report a help message
                         if !trait_ref.has_infer_types() &&
@@ -900,9 +902,11 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     /// When encountering an assignment of an unsized trait, like `let x = ""[..];`, provide a
     /// suggestion to borrow the initializer in order to use have a slice instead.
-    fn suggest_borrow_on_unsized_slice(&self,
+    fn suggest_borrow_on_unsized_slice(
-                                       code: &ObligationCauseCode<'tcx>,
+        &self,
-                                       err: &mut DiagnosticBuilder<'tcx>) {
+        code: &ObligationCauseCode<'tcx>,
+        err: &mut DiagnosticBuilder<'tcx>,
+    ) {
         if let &ObligationCauseCode::VariableType(node_id) = code {
             let parent_node = self.tcx.hir().get_parent_node(node_id);
             if let Some(Node::Local(ref local)) = self.tcx.hir().find(parent_node) {
@@ -924,10 +928,12 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     /// Whenever references are used by mistake, like `for (i, e) in &vec.iter().enumerate()`,
     /// suggest removing these references until we reach a type that implements the trait.
-    fn suggest_remove_reference(&self,
+    fn suggest_remove_reference(
-                                obligation: &PredicateObligation<'tcx>,
+        &self,
-                                err: &mut DiagnosticBuilder<'tcx>,
+        obligation: &PredicateObligation<'tcx>,
-                                trait_ref: &ty::Binder<ty::TraitRef<'tcx>>) {
+        err: &mut DiagnosticBuilder<'tcx>,
+        trait_ref: &ty::Binder<ty::TraitRef<'tcx>>,
+    ) {
         let trait_ref = trait_ref.skip_binder();
         let span = obligation.cause.span;
 
@@ -969,6 +975,40 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
+    fn suggest_semicolon_removal(
+        &self,
+        obligation: &PredicateObligation<'tcx>,
+        err: &mut DiagnosticBuilder<'tcx>,
+        span: Span,
+        trait_ref: &ty::Binder<ty::TraitRef<'tcx>>,
+    ) {
+        let hir = self.tcx.hir();
+        let parent_node = hir.get_parent_node(
+            hir.hir_to_node_id(obligation.cause.body_id),
+        );
+        let node = hir.find(parent_node);
+        if let Some(hir::Node::Item(hir::Item {
+            node: hir::ItemKind::Fn(decl, _, _, body_id),
+            ..
+        })) = node {
+            let body = hir.body(*body_id);
+            if let hir::ExprKind::Block(blk, _) = &body.value.node {
+                if decl.output.span().overlaps(span) && blk.expr.is_none() &&
+                    "()" == &trait_ref.self_ty().to_string()
+                {
+                    // FIXME(estebank): When encountering a method with a trait
+                    // bound not satisfied in the return type with a body that has
+                    // no return, suggest removal of semicolon on last statement.
+                    // Once that is added, close #54771.
+                    if let Some(ref stmt) = blk.stmts.last() {
+                        let sp = self.tcx.sess.source_map().end_point(stmt.span);
+                        err.span_label(sp, "consider removing this semicolon");
+                    }
+                }
+            }
+        }
+    }
+
     /// Given some node representing a fn-like thing in the HIR map,
     /// returns a span and `ArgKind` information that describes the
     /// arguments it expects. This can be supplied to

src/librustc_codegen_llvm/lib.rs

@@ -123,9 +123,9 @@ impl ExtraBackendMethods for LlvmCodegenBackend {
     ) -> EncodedMetadata {
         base::write_metadata(tcx, metadata)
     }
-    fn codegen_allocator(
+    fn codegen_allocator<'b, 'gcx>(
         &self,
-        tcx: TyCtxt<'_, '_, '_>,
+        tcx: TyCtxt<'b, 'gcx, 'gcx>,
         mods: &mut ModuleLlvm,
         kind: AllocatorKind
     ) {

src/librustc_codegen_ssa/back/write.rs

@@ -247,7 +247,7 @@ pub struct CodegenContext<B: WriteBackendMethods> {
 
 impl<B: WriteBackendMethods> CodegenContext<B> {
     pub fn create_diag_handler(&self) -> Handler {
-        Handler::with_emitter(true, false, Box::new(self.diag_emitter.clone()))
+        Handler::with_emitter(true, None, Box::new(self.diag_emitter.clone()))
     }
 
     pub fn config(&self, kind: ModuleKind) -> &ModuleConfig {

src/librustc_codegen_ssa/mir/mod.rs

@@ -673,6 +673,7 @@ fn arg_local_refs<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
                         .zip(state_tys)
                         .enumerate()
                         .filter_map(move |(i, (decl, ty))| {
+                            let ty = fx.monomorphize(&ty);
                             decl.name.map(|name| (i + upvar_count + 1, name, false, ty))
                         })
                 }).into_iter().flatten();

src/librustc_codegen_ssa/traits/backend.rs

@@ -38,9 +38,9 @@ pub trait ExtraBackendMethods: CodegenBackend + WriteBackendMethods + Sized + Se
         tcx: TyCtxt<'b, 'gcx, 'gcx>,
         metadata: &mut Self::Module,
     ) -> EncodedMetadata;
-    fn codegen_allocator(
+    fn codegen_allocator<'b, 'gcx>(
         &self,
-        tcx: TyCtxt<'_, '_, '_>,
+        tcx: TyCtxt<'b, 'gcx, 'gcx>,
         mods: &mut Self::Module,
         kind: AllocatorKind
     );

src/librustc_driver/lib.rs

@@ -148,7 +148,7 @@ pub fn run<F>(run_compiler: F) -> isize
                                 true,
                                 false
                             );
-                        let handler = errors::Handler::with_emitter(true, false, Box::new(emitter));
+                        let handler = errors::Handler::with_emitter(true, None, Box::new(emitter));
                         handler.emit(&MultiSpan::new(),
                                      "aborting due to previous error(s)",
                                      errors::Level::Fatal);
@@ -1327,7 +1327,7 @@ pub fn monitor<F: FnOnce() + Send + 'static>(f: F) -> Result<(), CompilationFail
                                                                 None,
                                                                 false,
                                                                 false));
-            let handler = errors::Handler::with_emitter(true, false, emitter);
+            let handler = errors::Handler::with_emitter(true, None, emitter);
 
             // a .span_bug or .bug call has already printed what
             // it wants to print.

src/librustc_driver/test.rs

@@ -113,7 +113,7 @@ fn test_env_with_pool<F>(
 ) where
     F: FnOnce(Env),
 {
-    let diagnostic_handler = errors::Handler::with_emitter(true, false, emitter);
+    let diagnostic_handler = errors::Handler::with_emitter(true, None, emitter);
     let sess = session::build_session_(
         options,
         None,

src/librustc_errors/diagnostic_builder.rs

@@ -103,7 +103,9 @@ impl<'a> DiagnosticBuilder<'a> {
     /// Buffers the diagnostic for later emission, unless handler
     /// has disabled such buffering.
     pub fn buffer(mut self, buffered_diagnostics: &mut Vec<Diagnostic>) {
-        if self.handler.flags.dont_buffer_diagnostics || self.handler.flags.treat_err_as_bug {
+        if self.handler.flags.dont_buffer_diagnostics ||
+            self.handler.flags.treat_err_as_bug.is_some()
+        {
             self.emit();
             return;
         }

src/librustc_errors/lib.rs

@@ -330,7 +330,7 @@ pub struct HandlerFlags {
     pub can_emit_warnings: bool,
     /// If true, error-level diagnostics are upgraded to bug-level.
     /// (rustc: see `-Z treat-err-as-bug`)
-    pub treat_err_as_bug: bool,
+    pub treat_err_as_bug: Option<usize>,
     /// If true, immediately emit diagnostics that would otherwise be buffered.
     /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
     pub dont_buffer_diagnostics: bool,
@@ -360,7 +360,7 @@ impl Drop for Handler {
 impl Handler {
     pub fn with_tty_emitter(color_config: ColorConfig,
                             can_emit_warnings: bool,
-                            treat_err_as_bug: bool,
+                            treat_err_as_bug: Option<usize>,
                             cm: Option<Lrc<SourceMapperDyn>>)
                             -> Handler {
         Handler::with_tty_emitter_and_flags(
@@ -382,7 +382,7 @@ impl Handler {
     }
 
     pub fn with_emitter(can_emit_warnings: bool,
-                        treat_err_as_bug: bool,
+                        treat_err_as_bug: Option<usize>,
                         e: Box<dyn Emitter + sync::Send>)
                         -> Handler {
         Handler::with_emitter_and_flags(
@@ -516,8 +516,20 @@ impl Handler {
     }
 
     fn panic_if_treat_err_as_bug(&self) {
-        if self.flags.treat_err_as_bug {
+        if self.treat_err_as_bug() {
-            panic!("encountered error with `-Z treat_err_as_bug");
+            let s = match (self.err_count(), self.flags.treat_err_as_bug.unwrap_or(0)) {
+                (0, _) => return,
+                (1, 1) => "aborting due to `-Z treat-err-as-bug=1`".to_string(),
+                (1, _) => return,
+                (count, as_bug) => {
+                    format!(
+                        "aborting after {} errors due to `-Z treat-err-as-bug={}`",
+                        count,
+                        as_bug,
+                    )
+                }
+            };
+            panic!(s);
         }
     }
 
@@ -558,7 +570,7 @@ impl Handler {
         panic!(ExplicitBug);
     }
     pub fn delay_span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
-        if self.flags.treat_err_as_bug {
+        if self.treat_err_as_bug() {
             // FIXME: don't abort here if report_delayed_bugs is off
             self.span_bug(sp, msg);
         }
@@ -593,14 +605,14 @@ impl Handler {
         DiagnosticBuilder::new(self, FailureNote, msg).emit()
     }
     pub fn fatal(&self, msg: &str) -> FatalError {
-        if self.flags.treat_err_as_bug {
+        if self.treat_err_as_bug() {
             self.bug(msg);
         }
         DiagnosticBuilder::new(self, Fatal, msg).emit();
         FatalError
     }
     pub fn err(&self, msg: &str) {
-        if self.flags.treat_err_as_bug {
+        if self.treat_err_as_bug() {
             self.bug(msg);
         }
         let mut db = DiagnosticBuilder::new(self, Error, msg);
@@ -610,6 +622,9 @@ impl Handler {
         let mut db = DiagnosticBuilder::new(self, Warning, msg);
         db.emit();
     }
+    fn treat_err_as_bug(&self) -> bool {
+        self.flags.treat_err_as_bug.map(|c| self.err_count() >= c).unwrap_or(false)
+    }
     pub fn note_without_error(&self, msg: &str) {
         let mut db = DiagnosticBuilder::new(self, Note, msg);
         db.emit();
@@ -624,8 +639,8 @@ impl Handler {
     }
 
     fn bump_err_count(&self) {
-        self.panic_if_treat_err_as_bug();
         self.err_count.fetch_add(1, SeqCst);
+        self.panic_if_treat_err_as_bug();
     }
 
     pub fn err_count(&self) -> usize {
@@ -642,6 +657,9 @@ impl Handler {
             1 => "aborting due to previous error".to_string(),
             _ => format!("aborting due to {} previous errors", self.err_count())
         };
+        if self.treat_err_as_bug() {
+            return;
+        }
 
         let _ = self.fatal(&s);
 

src/librustc_target/spec/armv6_unknown_freebsd.rs

@@ -0,0 +1,24 @@
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
+
+pub fn target() -> TargetResult {
+    let base = super::freebsd_base::opts();
+    Ok(Target {
+        llvm_target: "armv6-unknown-freebsd-gnueabihf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
+        arch: "arm".to_string(),
+        target_os: "freebsd".to_string(),
+        target_env: "gnueabihf".to_string(),
+        target_vendor: "unknown".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+
+        options: TargetOptions {
+            features: "+v6,+vfp2".to_string(),
+            max_atomic_width: Some(64),
+            abi_blacklist: super::arm_base::abi_blacklist(),
+            .. base
+        }
+    })
+}

src/librustc_target/spec/armv7_unknown_freebsd.rs

@@ -0,0 +1,24 @@
+use crate::spec::{LinkerFlavor, Target, TargetOptions, TargetResult};
+
+pub fn target() -> TargetResult {
+    let base = super::freebsd_base::opts();
+    Ok(Target {
+        llvm_target: "armv7-unknown-freebsd-gnueabihf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
+        arch: "arm".to_string(),
+        target_os: "freebsd".to_string(),
+        target_env: "gnueabihf".to_string(),
+        target_vendor: "unknown".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+
+        options: TargetOptions {
+            features: "+v7,+vfp3,+d16,+thumb2,-neon".to_string(),
+            max_atomic_width: Some(64),
+            abi_blacklist: super::arm_base::abi_blacklist(),
+            .. base
+        }
+    })
+}

src/librustc_target/spec/mod.rs

@@ -376,6 +376,8 @@ supported_targets! {
     ("aarch64-linux-android", aarch64_linux_android),
 
     ("aarch64-unknown-freebsd", aarch64_unknown_freebsd),
+    ("armv6-unknown-freebsd", armv6_unknown_freebsd),
+    ("armv7-unknown-freebsd", armv7_unknown_freebsd),
     ("i686-unknown-freebsd", i686_unknown_freebsd),
     ("powerpc64-unknown-freebsd", powerpc64_unknown_freebsd),
     ("x86_64-unknown-freebsd", x86_64_unknown_freebsd),

src/librustc_typeck/check/demand.rs

@@ -367,6 +367,15 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                         // Maybe remove `&`?
                         hir::ExprKind::AddrOf(_, ref expr) => {
                             if !cm.span_to_filename(expr.span).is_real() {
+                                if let Ok(code) = cm.span_to_snippet(sp) {
+                                    if code.chars().next() == Some('&') {
+                                        return Some((
+                                            sp,
+                                            "consider removing the borrow",
+                                            code[1..].to_string()),
+                                        );
+                                    }
+                                }
                                 return None;
                             }
                             if let Ok(code) = cm.span_to_snippet(expr.span) {

src/librustc_typeck/check/wfcheck.rs

@@ -251,11 +251,14 @@ fn check_type_defn<'a, 'tcx, F>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             let needs_drop_copy = || {
                 packed && {
                     let ty = variant.fields.last().unwrap().ty;
-                    let ty = fcx.tcx.erase_regions(&ty).lift_to_tcx(fcx_tcx)
+                    fcx.tcx.erase_regions(&ty).lift_to_tcx(fcx_tcx)
+                        .map(|ty| ty.needs_drop(fcx_tcx, fcx_tcx.param_env(def_id)))
                         .unwrap_or_else(|| {
-                            span_bug!(item.span, "inference variables in {:?}", ty)
+                            fcx_tcx.sess.delay_span_bug(
-                        });
+                                item.span, &format!("inference variables in {:?}", ty));
-                    ty.needs_drop(fcx_tcx, fcx_tcx.param_env(def_id))
+                            // Just treat unresolved type expression as if it needs drop.
+                            true
+                        })
                 }
             };
             let all_sized =
@@ -881,7 +884,9 @@ fn receiver_is_valid<'fcx, 'tcx, 'gcx>(
         } else {
             debug!("receiver_is_valid: type `{:?}` does not deref to `{:?}`",
                 receiver_ty, self_ty);
-            return false
+            // If he receiver already has errors reported due to it, consider it valid to avoid
+            // unecessary errors (#58712).
+            return receiver_ty.references_error();
         }
 
         // without the `arbitrary_self_types` feature, `receiver_ty` must directly deref to

src/librustdoc/core.rs

@@ -277,7 +277,7 @@ impl DocAccessLevels for AccessLevels<DefId> {
 /// will be created for the handler.
 pub fn new_handler(error_format: ErrorOutputType,
                    source_map: Option<Lrc<source_map::SourceMap>>,
-                   treat_err_as_bug: bool,
+                   treat_err_as_bug: Option<usize>,
                    ui_testing: bool,
 ) -> errors::Handler {
     // rustdoc doesn't override (or allow to override) anything from this that is relevant here, so

src/librustdoc/test.rs

@@ -67,7 +67,7 @@ pub fn run(mut options: Options) -> isize {
         let source_map = Lrc::new(SourceMap::new(sessopts.file_path_mapping()));
         let handler =
             errors::Handler::with_tty_emitter(ColorConfig::Auto,
-                                            true, false,
+                                            true, None,
                                             Some(source_map.clone()));
 
         let mut sess = session::build_session_(
@@ -272,7 +272,7 @@ fn run_test(test: &str, cratename: &str, filename: &FileName, line: usize,
                                                         false);
 
         // Compile the code
-        let diagnostic_handler = errors::Handler::with_emitter(true, false, box emitter);
+        let diagnostic_handler = errors::Handler::with_emitter(true, None, box emitter);
 
         let mut sess = session::build_session_(
             sessopts, None, diagnostic_handler, source_map, Default::default(),
@@ -424,7 +424,7 @@ pub fn make_test(s: &str,
         // send all the errors that libsyntax emits directly into a `Sink` instead of stderr.
         let cm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
         let emitter = EmitterWriter::new(box io::sink(), None, false, false);
-        let handler = Handler::with_emitter(false, false, box emitter);
+        let handler = Handler::with_emitter(false, None, box emitter);
         let sess = ParseSess::with_span_handler(handler, cm);
 
         let mut found_main = false;

src/libstd/collections/hash/map.rs

@@ -2341,6 +2341,11 @@ pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
     elem: FullBucket<K, V, &'a mut RawTable<K, V>>,
 }
 
+#[stable(feature = "rust1", since = "1.0.0")]
+unsafe impl<'a, K: 'a + Send, V: 'a + Send> Send for OccupiedEntry<'a, K, V> {}
+#[stable(feature = "rust1", since = "1.0.0")]
+unsafe impl<'a, K: 'a + Sync, V: 'a + Sync> Sync for OccupiedEntry<'a, K, V> {}
+
 #[stable(feature= "debug_hash_map", since = "1.12.0")]
 impl<K: Debug, V: Debug> Debug for OccupiedEntry<'_, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -2362,6 +2367,11 @@ pub struct VacantEntry<'a, K: 'a, V: 'a> {
     elem: VacantEntryState<K, V, &'a mut RawTable<K, V>>,
 }
 
+#[stable(feature = "rust1", since = "1.0.0")]
+unsafe impl<'a, K: 'a + Send, V: 'a + Send> Send for VacantEntry<'a, K, V> {}
+#[stable(feature = "rust1", since = "1.0.0")]
+unsafe impl<'a, K: 'a + Sync, V: 'a + Sync> Sync for VacantEntry<'a, K, V> {}
+
 #[stable(feature= "debug_hash_map", since = "1.12.0")]
 impl<K: Debug, V> Debug for VacantEntry<'_, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

src/libstd/io/error.rs

@@ -556,6 +556,14 @@ impl error::Error for Error {
             Repr::Custom(ref c) => c.error.cause(),
         }
     }
+
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match self.repr {
+            Repr::Os(..) => None,
+            Repr::Simple(..) => None,
+            Repr::Custom(ref c) => c.error.source(),
+        }
+    }
 }
 
 fn _assert_error_is_sync_send() {

src/libstd/thread/local.rs

@@ -40,13 +40,16 @@ use crate::mem;
 /// });
 ///
 /// // each thread starts out with the initial value of 1
-/// thread::spawn(move|| {
+/// let t = thread::spawn(move|| {
 ///     FOO.with(|f| {
 ///         assert_eq!(*f.borrow(), 1);
 ///         *f.borrow_mut() = 3;
 ///     });
 /// });
 ///
+/// // wait for the thread to complete and bail out on panic
+/// t.join().unwrap();
+///
 /// // we retain our original value of 2 despite the child thread
 /// FOO.with(|f| {
 ///     assert_eq!(*f.borrow(), 2);

src/libsyntax/parse/attr.rs

@@ -285,8 +285,8 @@ impl<'a> Parser<'a> {
         }
 
         let found = self.this_token_to_string();
-        let msg = format!("expected unsuffixed literal or identifier, found {}", found);
+        let msg = format!("expected unsuffixed literal or identifier, found `{}`", found);
-        Err(self.diagnostic().struct_span_err(lo, &msg))
+        Err(self.diagnostic().struct_span_err(self.span, &msg))
     }
 
     /// matches meta_seq = ( COMMASEP(meta_item_inner) )

src/libsyntax/parse/lexer/mod.rs

@@ -1920,7 +1920,7 @@ mod tests {
                                                           false,
                                                           false);
         ParseSess {
-            span_diagnostic: errors::Handler::with_emitter(true, false, Box::new(emitter)),
+            span_diagnostic: errors::Handler::with_emitter(true, None, Box::new(emitter)),
             unstable_features: UnstableFeatures::from_environment(),
             config: CrateConfig::default(),
             included_mod_stack: Lock::new(Vec::new()),

src/libsyntax/parse/mod.rs

@@ -54,7 +54,7 @@ impl ParseSess {
         let cm = Lrc::new(SourceMap::new(file_path_mapping));
         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
                                                 true,
-                                                false,
+                                                None,
                                                 Some(cm.clone()));
         ParseSess::with_span_handler(handler, cm)
     }

src/libsyntax/parse/parser.rs

@@ -1818,7 +1818,7 @@ impl<'a> Parser<'a> {
         let mut bounds = vec![GenericBound::Trait(poly_trait_ref, TraitBoundModifier::None)];
         if parse_plus {
             self.eat_plus(); // `+`, or `+=` gets split and `+` is discarded
-            bounds.append(&mut self.parse_generic_bounds(None)?);
+            bounds.append(&mut self.parse_generic_bounds(Some(self.prev_span))?);
         }
         Ok(TyKind::TraitObject(bounds, TraitObjectSyntax::None))
     }
@@ -5538,6 +5538,7 @@ impl<'a> Parser<'a> {
         let mut bounds = Vec::new();
         let mut negative_bounds = Vec::new();
         let mut last_plus_span = None;
+        let mut was_negative = false;
         loop {
             // This needs to be synchronized with `Token::can_begin_bound`.
             let is_bound_start = self.check_path() || self.check_lifetime() ||
@@ -5582,9 +5583,10 @@ impl<'a> Parser<'a> {
                     }
                     let poly_span = lo.to(self.prev_span);
                     if is_negative {
-                        negative_bounds.push(
+                        was_negative = true;
-                            last_plus_span.or(colon_span).unwrap()
+                        if let Some(sp) = last_plus_span.or(colon_span) {
-                                .to(poly_span));
+                            negative_bounds.push(sp.to(poly_span));
+                        }
                     } else {
                         let poly_trait = PolyTraitRef::new(lifetime_defs, path, poly_span);
                         let modifier = if question.is_some() {
@@ -5606,26 +5608,28 @@ impl<'a> Parser<'a> {
             }
         }
 
-        if !negative_bounds.is_empty() {
+        if !negative_bounds.is_empty() || was_negative {
             let plural = negative_bounds.len() > 1;
             let mut err = self.struct_span_err(negative_bounds,
                                                "negative trait bounds are not supported");
-            let bound_list = colon_span.unwrap().to(self.prev_span);
+            if let Some(bound_list) = colon_span {
-            let mut new_bound_list = String::new();
+                let bound_list = bound_list.to(self.prev_span);
-            if !bounds.is_empty() {
+                let mut new_bound_list = String::new();
-                let mut snippets = bounds.iter().map(|bound| bound.span())
+                if !bounds.is_empty() {
-                    .map(|span| self.sess.source_map().span_to_snippet(span));
+                    let mut snippets = bounds.iter().map(|bound| bound.span())
-                while let Some(Ok(snippet)) = snippets.next() {
+                        .map(|span| self.sess.source_map().span_to_snippet(span));
-                    new_bound_list.push_str(" + ");
+                    while let Some(Ok(snippet)) = snippets.next() {
-                    new_bound_list.push_str(&snippet);
+                        new_bound_list.push_str(" + ");
+                        new_bound_list.push_str(&snippet);
+                    }
+                    new_bound_list = new_bound_list.replacen(" +", ":", 1);
                 }
-                new_bound_list = new_bound_list.replacen(" +", ":", 1);
+                err.span_suggestion_short(bound_list,
+                                        &format!("remove the trait bound{}",
+                                                if plural { "s" } else { "" }),
+                                        new_bound_list,
+                                        Applicability::MachineApplicable);
             }
-            err.span_suggestion_short(bound_list,
-                                      &format!("remove the trait bound{}",
-                                              if plural { "s" } else { "" }),
-                                      new_bound_list,
-                                      Applicability::MachineApplicable);
             err.emit();
         }
 
@@ -5661,7 +5665,7 @@ impl<'a> Parser<'a> {
 
         // Parse optional colon and param bounds.
         let bounds = if self.eat(&token::Colon) {
-            self.parse_generic_bounds(None)?
+            self.parse_generic_bounds(Some(self.prev_span))?
         } else {
             Vec::new()
         };
@@ -6106,7 +6110,7 @@ impl<'a> Parser<'a> {
                 // or with mandatory equality sign and the second type.
                 let ty = self.parse_ty()?;
                 if self.eat(&token::Colon) {
-                    let bounds = self.parse_generic_bounds(None)?;
+                    let bounds = self.parse_generic_bounds(Some(self.prev_span))?;
                     where_clause.predicates.push(ast::WherePredicate::BoundPredicate(
                         ast::WhereBoundPredicate {
                             span: lo.to(self.prev_span),
@@ -7665,7 +7669,7 @@ impl<'a> Parser<'a> {
         tps.where_clause = self.parse_where_clause()?;
         let alias = if existential {
             self.expect(&token::Colon)?;
-            let bounds = self.parse_generic_bounds(None)?;
+            let bounds = self.parse_generic_bounds(Some(self.prev_span))?;
             AliasKind::Existential(bounds)
         } else {
             self.expect(&token::Eq)?;

src/libsyntax/test_snippet.rs

@@ -58,7 +58,7 @@ fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &
                                         Some(source_map.clone()),
                                         false,
                                         false);
-        let handler = Handler::with_emitter(true, false, Box::new(emitter));
+        let handler = Handler::with_emitter(true, None, Box::new(emitter));
         handler.span_err(msp, "foo");
 
         assert!(expected_output.chars().next() == Some('\n'),

src/test/incremental/cyclic-trait-hierarchy.rs

@@ -0,0 +1,14 @@
+// Adapated from rust-lang/rust#58813
+
+// revisions: rpass1 cfail2
+
+#[cfg(rpass1)]
+pub trait T2 { }
+#[cfg(cfail2)]
+pub trait T2: T1 { }
+//[cfail2]~^ ERROR cycle detected when computing the supertraits of `T2`
+//[cfail2]~| ERROR cycle detected when computing the supertraits of `T2`
+
+pub trait T1: T2 { }
+
+fn main() { }

src/test/run-make-fulldeps/treat-err-as-bug/Makefile

@@ -2,4 +2,4 @@
 
 all:
 	$(RUSTC) err.rs -Z treat-err-as-bug 2>&1 \
-	    | $(CGREP) "panicked at 'encountered error with \`-Z treat_err_as_bug'"
+	    | $(CGREP) "panicked at 'aborting due to \`-Z treat-err-as-bug=1\`'"

src/test/run-pass/generator/issue-57084.rs

@@ -0,0 +1,28 @@
+// This issue reproduces an ICE on compile (E.g. fails on 2018-12-19 nightly).
+// "cannot relate bound region: ReLateBound(DebruijnIndex(1), BrAnon(1)) <= '_#1r"
+// run-pass
+// edition:2018
+#![feature(generators,generator_trait)]
+use std::ops::Generator;
+
+fn with<F>(f: F) -> impl Generator<Yield=(), Return=()>
+where F: Fn() -> ()
+{
+    move || {
+        loop {
+            match f() {
+                _ => yield,
+            }
+        }
+    }
+}
+
+fn main() {
+    let data = &vec![1];
+    || {
+        let _to_pin = with(move || println!("{:p}", data));
+        loop {
+            yield
+        }
+    };
+}

src/test/run-pass/generator/issue-58888.rs

@@ -0,0 +1,27 @@
+// run-pass
+// compile-flags: -g
+
+#![feature(generators, generator_trait)]
+
+use std::ops::Generator;
+
+struct Database;
+
+impl Database {
+    fn get_connection(&self) -> impl Iterator<Item = ()> {
+        Some(()).into_iter()
+    }
+
+    fn check_connection(&self) -> impl Generator<Yield = (), Return = ()> + '_ {
+        move || {
+            let iter = self.get_connection();
+            for i in iter {
+                yield i
+            }
+        }
+    }
+}
+
+fn main() {
+    Database.check_connection();
+}

src/test/run-pass/issues/issue-58435-ice-with-assoc-const.rs

@@ -0,0 +1,17 @@
+// The const-evaluator was at one point ICE'ing while trying to
+// evaluate the body of `fn id` during the `s.id()` call in main.
+
+struct S<T>(T);
+
+impl<T> S<T> {
+    const ID: fn(&S<T>) -> &S<T> = |s| s;
+    pub fn id(&self) -> &Self {
+        Self::ID(self) // This, plus call below ...
+    }
+}
+
+fn main() {
+    let s = S(10u32);
+    assert!(S::<u32>::ID(&s).0 == 10); // Works fine
+    assert!(s.id().0 == 10); // ... causes compiler to panic
+}

src/test/run-pass/threads-sendsync/sync-send-iterators-in-libcollections.rs

@@ -53,6 +53,7 @@ fn main() {
     is_sync_send!(BTreeSet::<usize>::new(), union(&BTreeSet::<usize>::new()));
 
     all_sync_send!(HashMap::<usize, usize>::new(), iter, iter_mut, drain, into_iter, keys, values);
+    is_sync_send!(HashMap::<usize, usize>::new(), entry(0));
     all_sync_send!(HashSet::<usize>::new(), iter, drain, into_iter);
     is_sync_send!(HashSet::<usize>::new(), difference(&HashSet::<usize>::new()));
     is_sync_send!(HashSet::<usize>::new(), symmetric_difference(&HashSet::<usize>::new()));

src/test/ui/block-result/issue-5500.stderr

@@ -4,7 +4,10 @@ error[E0308]: mismatched types
 LL | fn main() {
    |           - expected `()` because of default return type
 LL |     &panic!()
-   |     ^^^^^^^^^ expected (), found reference
+   |     ^^^^^^^^^
+   |     |
+   |     expected (), found reference
+   |     help: consider removing the borrow: `panic!()`
    |
    = note: expected type `()`
               found type `&_`

src/test/ui/conditional-compilation/cfg-attr-syntax-validation.rs

@@ -28,7 +28,7 @@ struct S9;
 macro_rules! generate_s10 {
     ($expr: expr) => {
         #[cfg(feature = $expr)]
-        //~^ ERROR expected unsuffixed literal or identifier, found concat!("nonexistent")
+        //~^ ERROR expected unsuffixed literal or identifier, found `concat!("nonexistent")`
         struct S10;
     }
 }

src/test/ui/conditional-compilation/cfg-attr-syntax-validation.stderr

@@ -52,11 +52,11 @@ error[E0565]: literal in `cfg` predicate value must be a string
 LL | #[cfg(a = b"hi")]  //~ ERROR literal in `cfg` predicate value must be a string
    |           ^^^^^ help: consider removing the prefix: `"hi"`
 
-error: expected unsuffixed literal or identifier, found concat!("nonexistent")
+error: expected unsuffixed literal or identifier, found `concat!("nonexistent")`
-  --> $DIR/cfg-attr-syntax-validation.rs:30:15
+  --> $DIR/cfg-attr-syntax-validation.rs:30:25
    |
 LL |         #[cfg(feature = $expr)]
-   |               ^^^^^^^
+   |                         ^^^^^
 ...
 LL | generate_s10!(concat!("nonexistent"));
    | -------------------------------------- in this macro invocation

src/test/ui/const-generics/invalid-constant-in-args.rs

@@ -0,0 +1,3 @@
+fn main() {
+    let _: Vec<&str, "a"> = Vec::new(); //~ ERROR wrong number of const arguments
+}

src/test/ui/const-generics/invalid-constant-in-args.stderr

@@ -0,0 +1,9 @@
+error[E0107]: wrong number of const arguments: expected 0, found 1
+  --> $DIR/invalid-constant-in-args.rs:2:22
+   |
+LL |     let _: Vec<&str, "a"> = Vec::new(); //~ ERROR wrong number of const arguments
+   |                      ^^^ unexpected const argument
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0107`.

src/test/ui/diverging-tuple-parts-39485.stderr

@@ -1,13 +1,19 @@
 error[E0308]: mismatched types
   --> $DIR/diverging-tuple-parts-39485.rs:8:5
    |
-LL | fn g() {
-   |        - help: try adding a return type: `-> &_`
 LL |     &panic!() //~ ERROR mismatched types
    |     ^^^^^^^^^ expected (), found reference
    |
    = note: expected type `()`
               found type `&_`
+help: try adding a return type
+   |
+LL | fn g() -> &_ {
+   |        ^^^^^
+help: consider removing the borrow
+   |
+LL |     panic!() //~ ERROR mismatched types
+   |     ^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/diverging-tuple-parts-39485.rs:12:5

src/test/ui/issues/issue-50582.rs

@@ -0,0 +1,4 @@
+fn main() {
+    Vec::<[(); 1 + for x in 0..1 {}]>::new();
+    //~^ ERROR cannot add
+}

src/test/ui/issues/issue-50582.stderr

@@ -0,0 +1,11 @@
+error[E0277]: cannot add `()` to `{integer}`
+  --> $DIR/issue-50582.rs:2:18
+   |
+LL |     Vec::<[(); 1 + for x in 0..1 {}]>::new();
+   |                  ^ no implementation for `{integer} + ()`
+   |
+   = help: the trait `std::ops::Add<()>` is not implemented for `{integer}`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.

src/test/ui/issues/issue-58712.rs

@@ -0,0 +1,15 @@
+struct AddrVec<H, A> {
+    h: H,
+    a: A,
+}
+
+impl<H> AddrVec<H, DeviceId> {
+    //~^ ERROR cannot find type `DeviceId` in this scope
+    pub fn device(&self) -> DeviceId {
+    //~^ ERROR cannot find type `DeviceId` in this scope
+        self.tail()
+    }
+}
+
+fn main() {}
+

src/test/ui/issues/issue-58712.stderr

@@ -0,0 +1,15 @@
+error[E0412]: cannot find type `DeviceId` in this scope
+  --> $DIR/issue-58712.rs:6:20
+   |
+LL | impl<H> AddrVec<H, DeviceId> {
+   |                    ^^^^^^^^ not found in this scope
+
+error[E0412]: cannot find type `DeviceId` in this scope
+  --> $DIR/issue-58712.rs:8:29
+   |
+LL |     pub fn device(&self) -> DeviceId {
+   |                             ^^^^^^^^ not found in this scope
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0412`.

src/test/ui/issues/issue-58857.rs

@@ -0,0 +1,7 @@
+struct Conj<A> {a : A}
+trait Valid {}
+
+impl<A: !Valid> Conj<A>{}
+//~^ ERROR negative trait bounds are not supported
+
+fn main() {}

src/test/ui/issues/issue-58857.stderr

@@ -0,0 +1,8 @@
+error: negative trait bounds are not supported
+  --> $DIR/issue-58857.rs:4:7
+   |
+LL | impl<A: !Valid> Conj<A>{}
+   |       ^^^^^^^^ help: remove the trait bound
+
+error: aborting due to previous error
+

src/test/ui/suggestions/format-borrow.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let a: String = &String::from("a");
+    //~^ ERROR mismatched types
+    let b: String = &format!("b");
+    //~^ ERROR mismatched types
+}

src/test/ui/suggestions/format-borrow.stderr

@@ -0,0 +1,27 @@
+error[E0308]: mismatched types
+  --> $DIR/format-borrow.rs:2:21
+   |
+LL |     let a: String = &String::from("a");
+   |                     ^^^^^^^^^^^^^^^^^^
+   |                     |
+   |                     expected struct `std::string::String`, found reference
+   |                     help: consider removing the borrow: `String::from("a")`
+   |
+   = note: expected type `std::string::String`
+              found type `&std::string::String`
+
+error[E0308]: mismatched types
+  --> $DIR/format-borrow.rs:4:21
+   |
+LL |     let b: String = &format!("b");
+   |                     ^^^^^^^^^^^^^
+   |                     |
+   |                     expected struct `std::string::String`, found reference
+   |                     help: consider removing the borrow: `format!("b")`
+   |
+   = note: expected type `std::string::String`
+              found type `&std::string::String`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/suggestions/impl-trait-return-trailing-semicolon.rs

@@ -0,0 +1,7 @@
+trait Bar {}
+impl Bar for u8 {}
+fn foo() -> impl Bar {
+    5; //~^ ERROR the trait bound `(): Bar` is not satisfied
+}
+
+fn main() {}

src/test/ui/suggestions/impl-trait-return-trailing-semicolon.stderr

@@ -0,0 +1,13 @@
+error[E0277]: the trait bound `(): Bar` is not satisfied
+  --> $DIR/impl-trait-return-trailing-semicolon.rs:3:13
+   |
+LL | fn foo() -> impl Bar {
+   |             ^^^^^^^^ the trait `Bar` is not implemented for `()`
+LL |     5; //~^ ERROR the trait bound `(): Bar` is not satisfied
+   |      - consider removing this semicolon
+   |
+   = note: the return type of a function must have a statically known size
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.

src/test/ui/suggestions/unused-closure-argument.rs

@@ -0,0 +1,20 @@
+#![deny(unused_variables)]
+
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+fn main() {
+    let points = vec!(Point { x: 1, y: 2 }, Point { x: 3, y: 4 });
+
+    let _: i32 = points.iter()
+        .map(|Point { x, y }| y)
+        //~^ ERROR unused variable
+        .sum();
+
+    let _: i32 = points.iter()
+        .map(|x| 4)
+        //~^ ERROR unused variable
+        .sum();
+}

src/test/ui/suggestions/unused-closure-argument.stderr

@@ -0,0 +1,20 @@
+error: unused variable: `x`
+  --> $DIR/unused-closure-argument.rs:12:23
+   |
+LL |         .map(|Point { x, y }| y)
+   |                       ^ help: try ignoring the field: `x: _`
+   |
+note: lint level defined here
+  --> $DIR/unused-closure-argument.rs:1:9
+   |
+LL | #![deny(unused_variables)]
+   |         ^^^^^^^^^^^^^^^^
+
+error: unused variable: `x`
+  --> $DIR/unused-closure-argument.rs:17:15
+   |
+LL |         .map(|x| 4)
+   |               ^ help: consider prefixing with an underscore: `_x`
+
+error: aborting due to 2 previous errors
+

src/test/ui/wf/wf-packed-on-proj-of-type-as-unimpl-trait.rs

@@ -0,0 +1,31 @@
+// rust-lang/rust#58158: We have special-case code to deal with case
+// when a type is both packed and needs drop glue, (we move the fields
+// out of their potentially unaligned locations before dropping them,
+// which requires they be Sized; see PR #44884).
+//
+// So, we need to check if a given type needs drop-glue. That requires
+// that we actually know that the concrete type, and we guard against
+// the type having unknown parts (i.e. type variables) by ICE'ing in
+// that scenario.
+//
+// But in a case where we have a projection (`Type as Trait::Assoc`)
+// where `Type` does not actually implement `Trait`, we of course
+// cannot have a concrete type, because there is no impl to look up
+// the concrete type for the associated type `Assoc`.
+//
+// So, this test is just making sure that in such a case that we do
+// not immediately ICE, and instead allow the underlying type error to
+// surface.
+
+pub struct Matrix<S>(S);
+pub struct DefaultAllocator;
+
+pub trait Allocator { type Buffer; }
+
+// impl Allocator for DefaultAllocator { type Buffer = (); }
+
+#[repr(packed)]
+struct Foo(Matrix<<DefaultAllocator as Allocator>::Buffer>);
+//~^ ERROR the trait bound `DefaultAllocator: Allocator` is not satisfied
+
+fn main() { }

src/test/ui/wf/wf-packed-on-proj-of-type-as-unimpl-trait.stderr

@@ -0,0 +1,9 @@
+error[E0277]: the trait bound `DefaultAllocator: Allocator` is not satisfied
+  --> $DIR/wf-packed-on-proj-of-type-as-unimpl-trait.rs:28:12
+   |
+LL | struct Foo(Matrix<<DefaultAllocator as Allocator>::Buffer>);
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Allocator` is not implemented for `DefaultAllocator`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.