Auto merge of #63607 - Centril:rollup-yry7nsw, r=Centril

Rollup of 5 pull requests

Successful merges:

 - #63173 (Use libunwind from llvm-project submodule for musl targets)
 - #63462 (Opaque builtin derive macros)
 - #63539 (Suggest Rust 2018 on `<expr>.await` with no such field)
 - #63545 (Feature gate 'yield $expr?' pre-expansion)
 - #63584 (libcore: more cleanups using `#![feature(associated_type_bounds)]`)

Failed merges:

r? @ghost

src/bootstrap/sanity.rs

@@ -202,10 +202,6 @@ pub fn check(build: &mut Build) {
                         panic!("couldn't find libc.a in musl dir: {}",
                                root.join("lib").display());
                     }
-                    if fs::metadata(root.join("lib/libunwind.a")).is_err() {
-                        panic!("couldn't find libunwind.a in musl dir: {}",
-                               root.join("lib").display());
-                    }
                 }
                 None => {
                     panic!("when targeting MUSL either the rust.musl-root \

src/ci/docker/scripts/musl-toolchain.sh

@@ -54,29 +54,3 @@ if [ "$REPLACE_CC" = "1" ]; then
         ln -s $TARGET-g++ /usr/local/bin/$exec
     done
 fi
-
-export CC=$TARGET-gcc
-export CXX=$TARGET-g++
-
-LLVM=70
-
-# may have been downloaded in a previous run
-if [ ! -d libunwind-release_$LLVM ]; then
-  curl -L https://github.com/llvm-mirror/llvm/archive/release_$LLVM.tar.gz | tar xzf -
-  curl -L https://github.com/llvm-mirror/libunwind/archive/release_$LLVM.tar.gz | tar xzf -
-fi
-
-# fixme(mati865): Replace it with https://github.com/rust-lang/rust/pull/59089
-mkdir libunwind-build
-cd libunwind-build
-cmake ../libunwind-release_$LLVM \
-          -DLLVM_PATH=/build/llvm-release_$LLVM \
-          -DLIBUNWIND_ENABLE_SHARED=0 \
-          -DCMAKE_C_COMPILER=$CC \
-          -DCMAKE_CXX_COMPILER=$CXX \
-          -DCMAKE_C_FLAGS="$CFLAGS" \
-          -DCMAKE_CXX_FLAGS="$CXXFLAGS"
-
-hide_output make -j$(nproc)
-cp lib/libunwind.a $OUTPUT/$TARGET/lib
-cd - && rm -rf libunwind-build

src/ci/docker/scripts/musl.sh

@@ -20,6 +20,8 @@ exit 1
 TAG=$1
 shift
 
+# Ancient binutils versions don't understand debug symbols produced by more recent tools.
+# Apparently applying `-fPIC` everywhere allows them to link successfully.
 export CFLAGS="-fPIC $CFLAGS"
 
 MUSL=musl-1.1.22
@@ -38,27 +40,3 @@ else
 fi
 hide_output make install
 hide_output make clean
-
-cd ..
-
-LLVM=70
-
-# may have been downloaded in a previous run
-if [ ! -d libunwind-release_$LLVM ]; then
-  curl -L https://github.com/llvm-mirror/llvm/archive/release_$LLVM.tar.gz | tar xzf -
-  curl -L https://github.com/llvm-mirror/libunwind/archive/release_$LLVM.tar.gz | tar xzf -
-fi
-
-mkdir libunwind-build
-cd libunwind-build
-cmake ../libunwind-release_$LLVM \
-          -DLLVM_PATH=/build/llvm-release_$LLVM \
-          -DLIBUNWIND_ENABLE_SHARED=0 \
-          -DCMAKE_C_COMPILER=$CC \
-          -DCMAKE_CXX_COMPILER=$CXX \
-          -DCMAKE_C_FLAGS="$CFLAGS" \
-          -DCMAKE_CXX_FLAGS="$CXXFLAGS"
-
-hide_output make -j$(nproc)
-cp lib/libunwind.a /musl-$TAG/lib
-cd ../ && rm -rf libunwind-build

src/libcore/clone.rs

@@ -135,7 +135,6 @@ pub trait Clone : Sized {
 
 /// Derive macro generating an impl of the trait `Clone`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics, derive_clone_copy)]
 pub macro Clone($item:item) { /* compiler built-in */ }

src/libcore/cmp.rs

@@ -202,7 +202,6 @@ pub trait PartialEq<Rhs: ?Sized = Self> {
 
 /// Derive macro generating an impl of the trait `PartialEq`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics)]
 pub macro PartialEq($item:item) { /* compiler built-in */ }
@@ -265,7 +264,6 @@ pub trait Eq: PartialEq<Self> {
 
 /// Derive macro generating an impl of the trait `Eq`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics, derive_eq)]
 pub macro Eq($item:item) { /* compiler built-in */ }
@@ -616,7 +614,6 @@ pub trait Ord: Eq + PartialOrd<Self> {
 
 /// Derive macro generating an impl of the trait `Ord`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics)]
 pub macro Ord($item:item) { /* compiler built-in */ }
@@ -865,7 +862,6 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
 
 /// Derive macro generating an impl of the trait `PartialOrd`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics)]
 pub macro PartialOrd($item:item) { /* compiler built-in */ }

src/libcore/default.rs

@@ -117,7 +117,6 @@ pub trait Default: Sized {
 
 /// Derive macro generating an impl of the trait `Default`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics)]
 pub macro Default($item:item) { /* compiler built-in */ }

src/libcore/fmt/builders.rs

@@ -98,7 +98,7 @@ pub struct DebugStruct<'a, 'b: 'a> {
     has_fields: bool,
 }
 
-pub fn debug_struct_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>,
+pub(super) fn debug_struct_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>,
                                 name: &str)
                                 -> DebugStruct<'a, 'b> {
     let result = fmt.write_str(name);
@@ -251,7 +251,10 @@ pub struct DebugTuple<'a, 'b: 'a> {
     empty_name: bool,
 }
 
-pub fn debug_tuple_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>, name: &str) -> DebugTuple<'a, 'b> {
+pub(super) fn debug_tuple_new<'a, 'b>(
+    fmt: &'a mut fmt::Formatter<'b>,
+    name: &str,
+) -> DebugTuple<'a, 'b> {
     let result = fmt.write_str(name);
     DebugTuple {
         fmt,
@@ -418,7 +421,7 @@ pub struct DebugSet<'a, 'b: 'a> {
     inner: DebugInner<'a, 'b>,
 }
 
-pub fn debug_set_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugSet<'a, 'b> {
+pub(super) fn debug_set_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugSet<'a, 'b> {
     let result = fmt.write_str("{");
     DebugSet {
         inner: DebugInner {
@@ -555,7 +558,7 @@ pub struct DebugList<'a, 'b: 'a> {
     inner: DebugInner<'a, 'b>,
 }
 
-pub fn debug_list_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugList<'a, 'b> {
+pub(super) fn debug_list_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugList<'a, 'b> {
     let result = fmt.write_str("[");
     DebugList {
         inner: DebugInner {
@@ -697,7 +700,7 @@ pub struct DebugMap<'a, 'b: 'a> {
     state: PadAdapterState,
 }
 
-pub fn debug_map_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugMap<'a, 'b> {
+pub(super) fn debug_map_new<'a, 'b>(fmt: &'a mut fmt::Formatter<'b>) -> DebugMap<'a, 'b> {
     let result = fmt.write_str("{");
     DebugMap {
         fmt,

src/libcore/fmt/mod.rs

@@ -549,7 +549,6 @@ pub trait Debug {
 pub(crate) mod macros {
     /// Derive macro generating an impl of the trait `Debug`.
     #[rustc_builtin_macro]
-    #[rustc_macro_transparency = "semitransparent"]
     #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
     #[allow_internal_unstable(core_intrinsics)]
     pub macro Debug($item:item) { /* compiler built-in */ }

src/libcore/hash/mod.rs

@@ -202,7 +202,6 @@ pub trait Hash {
 pub(crate) mod macros {
     /// Derive macro generating an impl of the trait `Hash`.
     #[rustc_builtin_macro]
-    #[rustc_macro_transparency = "semitransparent"]
     #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
     #[allow_internal_unstable(core_intrinsics)]
     pub macro Hash($item:item) { /* compiler built-in */ }

src/libcore/iter/adapters/flatten.rs

@@ -72,8 +72,7 @@ impl<I: Iterator, U: IntoIterator, F> Iterator for FlatMap<I, U, F>
 impl<I: DoubleEndedIterator, U, F> DoubleEndedIterator for FlatMap<I, U, F>
 where
     F: FnMut(I::Item) -> U,
-    U: IntoIterator,
-    U::IntoIter: DoubleEndedIterator,
+    U: IntoIterator<IntoIter: DoubleEndedIterator>,
 {
     #[inline]
     fn next_back(&mut self) -> Option<U::Item> { self.inner.next_back() }
@@ -107,10 +106,7 @@ impl<I, U, F> FusedIterator for FlatMap<I, U, F>
 /// [`Iterator`]: trait.Iterator.html
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 #[stable(feature = "iterator_flatten", since = "1.29.0")]
-pub struct Flatten<I: Iterator>
-where
-    I::Item: IntoIterator,
-{
+pub struct Flatten<I: Iterator<Item: IntoIterator>> {
     inner: FlattenCompat<I, <I::Item as IntoIterator>::IntoIter>,
 }
 

src/libcore/macros.rs

@@ -1270,14 +1270,12 @@ pub(crate) mod builtin {
 
     /// Unstable implementation detail of the `rustc` compiler, do not use.
     #[rustc_builtin_macro]
-    #[rustc_macro_transparency = "semitransparent"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[allow_internal_unstable(core_intrinsics, libstd_sys_internals)]
     pub macro RustcDecodable($item:item) { /* compiler built-in */ }
 
     /// Unstable implementation detail of the `rustc` compiler, do not use.
     #[rustc_builtin_macro]
-    #[rustc_macro_transparency = "semitransparent"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[allow_internal_unstable(core_intrinsics)]
     pub macro RustcEncodable($item:item) { /* compiler built-in */ }

src/libcore/marker.rs

@@ -290,7 +290,6 @@ pub trait Copy : Clone {
 
 /// Derive macro generating an impl of the trait `Copy`.
 #[rustc_builtin_macro]
-#[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow_internal_unstable(core_intrinsics, derive_clone_copy)]
 pub macro Copy($item:item) { /* compiler built-in */ }

src/librustc/hir/lowering/expr.rs

@@ -984,7 +984,6 @@ impl LoweringContext<'_> {
             volatile: asm.volatile,
             alignstack: asm.alignstack,
             dialect: asm.dialect,
-            ctxt: asm.ctxt,
         };
 
         let outputs = asm.outputs

src/librustc/hir/lowering/item.rs

@@ -750,10 +750,7 @@ impl LoweringContext<'_> {
     }
 
     fn lower_global_asm(&mut self, ga: &GlobalAsm) -> P<hir::GlobalAsm> {
-        P(hir::GlobalAsm {
-            asm: ga.asm,
-            ctxt: ga.ctxt,
-        })
+        P(hir::GlobalAsm { asm: ga.asm })
     }
 
     fn lower_variant(&mut self, v: &Variant) -> hir::Variant {

src/librustc/hir/mod.rs

@@ -23,7 +23,6 @@ use rustc_target::spec::abi::Abi;
 use syntax::ast::{self, CrateSugar, Ident, Name, NodeId, AsmDialect};
 use syntax::ast::{Attribute, Label, LitKind, StrStyle, FloatTy, IntTy, UintTy};
 use syntax::attr::{InlineAttr, OptimizeAttr};
-use syntax::ext::hygiene::SyntaxContext;
 use syntax::symbol::{Symbol, kw};
 use syntax::tokenstream::TokenStream;
 use syntax::util::parser::ExprPrecedence;
@@ -2004,8 +2003,6 @@ pub struct InlineAsm {
     pub volatile: bool,
     pub alignstack: bool,
     pub dialect: AsmDialect,
-    #[stable_hasher(ignore)] // This is used for error reporting
-    pub ctxt: SyntaxContext,
 }
 
 /// Represents an argument in a function header.
@@ -2184,8 +2181,6 @@ pub struct ForeignMod {
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]
 pub struct GlobalAsm {
     pub asm: Symbol,
-    #[stable_hasher(ignore)] // This is used for error reporting
-    pub ctxt: SyntaxContext,
 }
 
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]

src/librustc_codegen_llvm/asm.rs

@@ -6,9 +6,9 @@ use crate::value::Value;
 
 use rustc::hir;
 use rustc_codegen_ssa::traits::*;
-
 use rustc_codegen_ssa::mir::place::PlaceRef;
 use rustc_codegen_ssa::mir::operand::OperandValue;
+use syntax_pos::Span;
 
 use std::ffi::{CStr, CString};
 use libc::{c_uint, c_char};
@@ -19,7 +19,8 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         ia: &hir::InlineAsm,
         outputs: Vec<PlaceRef<'tcx, &'ll Value>>,
-        mut inputs: Vec<&'ll Value>
+        mut inputs: Vec<&'ll Value>,
+        span: Span,
     ) -> bool {
         let mut ext_constraints = vec![];
         let mut output_types = vec![];
@@ -102,7 +103,7 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
             let kind = llvm::LLVMGetMDKindIDInContext(self.llcx,
                 key.as_ptr() as *const c_char, key.len() as c_uint);
 
-            let val: &'ll Value = self.const_i32(ia.ctxt.outer_expn().as_u32() as i32);
+            let val: &'ll Value = self.const_i32(span.ctxt().outer_expn().as_u32() as i32);
 
             llvm::LLVMSetMetadata(r, kind,
                 llvm::LLVMMDNodeInContext(self.llcx, &val, 1));

src/librustc_codegen_ssa/mir/statement.rs

@@ -89,7 +89,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 });
 
                 if input_vals.len() == asm.inputs.len() {
-                    let res = bx.codegen_inline_asm(&asm.asm, outputs, input_vals);
+                    let res = bx.codegen_inline_asm(
+                        &asm.asm,
+                        outputs,
+                        input_vals,
+                        statement.source_info.span,
+                    );
                     if !res {
                         span_err!(bx.sess(), statement.source_info.span, E0668,
                                   "malformed inline assembly");

src/librustc_codegen_ssa/traits/asm.rs

@@ -1,6 +1,7 @@
 use super::BackendTypes;
 use crate::mir::place::PlaceRef;
 use rustc::hir::{GlobalAsm, InlineAsm};
+use syntax_pos::Span;
 
 pub trait AsmBuilderMethods<'tcx>: BackendTypes {
     /// Take an inline assembly expression and splat it out via LLVM
@@ -9,6 +10,7 @@ pub trait AsmBuilderMethods<'tcx>: BackendTypes {
         ia: &InlineAsm,
         outputs: Vec<PlaceRef<'tcx, Self::Value>>,
         inputs: Vec<Self::Value>,
+        span: Span,
     ) -> bool;
 }
 

src/librustc_metadata/decoder.rs

@@ -348,6 +348,14 @@ impl<'a, 'tcx> SpecializedDecoder<Span> for DecodeContext<'a, 'tcx> {
     }
 }
 
+impl SpecializedDecoder<Ident> for DecodeContext<'_, '_> {
+    fn specialized_decode(&mut self) -> Result<Ident, Self::Error> {
+        // FIXME(jseyfried): intercrate hygiene
+
+        Ok(Ident::with_empty_ctxt(Symbol::decode(self)?))
+    }
+}
+
 impl<'a, 'tcx> SpecializedDecoder<Fingerprint> for DecodeContext<'a, 'tcx> {
     fn specialized_decode(&mut self) -> Result<Fingerprint, Self::Error> {
         Fingerprint::decode_opaque(&mut self.opaque)

src/librustc_metadata/encoder.rs

@@ -31,7 +31,7 @@ use std::u32;
 use syntax::ast;
 use syntax::attr;
 use syntax::source_map::Spanned;
-use syntax::symbol::{kw, sym};
+use syntax::symbol::{kw, sym, Ident};
 use syntax_pos::{self, FileName, SourceFile, Span};
 use log::{debug, trace};
 
@@ -173,6 +173,13 @@ impl<'tcx> SpecializedEncoder<Span> for EncodeContext<'tcx> {
     }
 }
 
+impl SpecializedEncoder<Ident> for EncodeContext<'tcx> {
+    fn specialized_encode(&mut self, ident: &Ident) -> Result<(), Self::Error> {
+        // FIXME(jseyfried): intercrate hygiene
+        ident.name.encode(self)
+    }
+}
+
 impl<'tcx> SpecializedEncoder<LocalDefId> for EncodeContext<'tcx> {
     #[inline]
     fn specialized_encode(&mut self, def_id: &LocalDefId) -> Result<(), Self::Error> {

src/librustc_resolve/diagnostics.rs

@@ -166,12 +166,14 @@ impl<'a> Resolver<'a> {
                 err
             }
             ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => {
-                let mut err = struct_span_err!(self.session,
-                                                span,
-                                                E0403,
-                                                "the name `{}` is already used for a generic \
-                                                parameter in this list of generic parameters",
-                                                name);
+                let mut err = struct_span_err!(
+                    self.session,
+                    span,
+                    E0403,
+                    "the name `{}` is already used for a generic \
+                     parameter in this item's generic parameters",
+                    name,
+                );
                 err.span_label(span, "already used");
                 err.span_label(first_use_span, format!("first use of `{}`", name));
                 err