Auto merge of rust-lang#85458 - jackh726:rollup-zvvybmt, r=jackh726

Rollup of 8 pull requests

Successful merges:

 - rust-lang#83366 (Stabilize extended_key_value_attributes)
 - rust-lang#83767 (Fix v0 symbol mangling bug)
 - rust-lang#84883 (compiletest: "fix" FileCheck with --allow-unused-prefixes)
 - rust-lang#85274 (Only pass --[no-]gc-sections if linker is GNU ld.)
 - rust-lang#85297 (bootstrap: build cargo only if requested in tools)
 - rust-lang#85396 (rustdoc: restore header sizes)
 - rust-lang#85425 (Fix must_use on `Option::is_none`)
 - rust-lang#85438 (Fix escape handling)

Failed merges:

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

Author: bors

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -712,10 +712,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
     gate_all!(const_trait_impl, "const trait impls are experimental");
     gate_all!(half_open_range_patterns, "half-open range patterns are unstable");
     gate_all!(inline_const, "inline-const is experimental");
-    gate_all!(
-        extended_key_value_attributes,
-        "arbitrary expressions in key-value attributes are unstable"
-    );
     gate_all!(
         const_generics_defaults,
         "default values for const generic parameters are experimental"

compiler/rustc_codegen_llvm/src/lib.rs

@@ -8,7 +8,7 @@
 #![feature(bool_to_option)]
 #![feature(const_cstr_unchecked)]
 #![feature(crate_visibility_modifier)]
-#![feature(extended_key_value_attributes)]
+#![cfg_attr(bootstrap, feature(extended_key_value_attributes))]
 #![feature(extern_types)]
 #![feature(in_band_lifetimes)]
 #![feature(iter_zip)]

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -281,8 +281,11 @@ impl<'a> Linker for GccLinker<'a> {
                 }
             }
             LinkOutputKind::DynamicPicExe => {
-                // `-pie` works for both gcc wrapper and ld.
-                self.cmd.arg("-pie");
+                // noop on windows w/ gcc & ld, error w/ lld
+                if !self.sess.target.is_like_windows {
+                    // `-pie` works for both gcc wrapper and ld.
+                    self.cmd.arg("-pie");
+                }
             }
             LinkOutputKind::StaticNoPicExe => {
                 // `-static` works for both gcc wrapper and ld.
@@ -347,7 +350,7 @@ impl<'a> Linker for GccLinker<'a> {
                 // has -needed-l{} / -needed_library {}
                 // but we have no way to detect that here.
                 self.sess.warn("`as-needed` modifier not implemented yet for ld64");
-            } else if self.sess.target.linker_is_gnu {
+            } else if self.sess.target.linker_is_gnu && !self.sess.target.is_like_windows {
                 self.linker_arg("--no-as-needed");
             } else {
                 self.sess.warn("`as-needed` modifier not supported for current linker");
@@ -358,7 +361,7 @@ impl<'a> Linker for GccLinker<'a> {
         if !as_needed {
             if self.sess.target.is_like_osx {
                 // See above FIXME comment
-            } else if self.sess.target.linker_is_gnu {
+            } else if self.sess.target.linker_is_gnu && !self.sess.target.is_like_windows {
                 self.linker_arg("--as-needed");
             }
         }
@@ -469,17 +472,15 @@ impl<'a> Linker for GccLinker<'a> {
         // eliminate the metadata. If we're building an executable, however,
         // --gc-sections drops the size of hello world from 1.8MB to 597K, a 67%
         // reduction.
-        } else if !keep_metadata {
+        } else if self.sess.target.linker_is_gnu && !keep_metadata {
             self.linker_arg("--gc-sections");
         }
     }
 
     fn no_gc_sections(&mut self) {
         if self.sess.target.is_like_osx {
             self.linker_arg("-no_dead_strip");
-        } else if self.sess.target.is_like_solaris {
-            self.linker_arg("-zrecord");
-        } else {
+        } else if self.sess.target.linker_is_gnu {
             self.linker_arg("--no-gc-sections");
         }
     }
@@ -692,7 +693,7 @@ impl<'a> Linker for GccLinker<'a> {
     }
 
     fn add_as_needed(&mut self) {
-        if self.sess.target.linker_is_gnu {
+        if self.sess.target.linker_is_gnu && !self.sess.target.is_like_windows {
             self.linker_arg("--as-needed");
         } else if self.sess.target.is_like_solaris {
             // -z ignore is the Solaris equivalent to the GNU ld --as-needed option

compiler/rustc_errors/src/lib.rs

@@ -5,7 +5,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(crate_visibility_modifier)]
 #![feature(backtrace)]
-#![feature(extended_key_value_attributes)]
+#![cfg_attr(bootstrap, feature(extended_key_value_attributes))]
 #![feature(format_args_capture)]
 #![feature(iter_zip)]
 #![feature(nll)]

compiler/rustc_feature/src/accepted.rs

@@ -281,6 +281,8 @@ declare_features! (
     (accepted, or_patterns, "1.53.0", Some(54883), None),
     /// Allows defining identifiers beyond ASCII.
     (accepted, non_ascii_idents, "1.53.0", Some(55467), None),
+    /// Allows arbitrary expressions in key-value attributes at parse time.
+    (accepted, extended_key_value_attributes, "1.54.0", Some(78835), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features

compiler/rustc_feature/src/active.rs

@@ -601,9 +601,6 @@ declare_features! (
     /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
     (active, capture_disjoint_fields, "1.49.0", Some(53488), None),
 
-    /// Allows arbitrary expressions in key-value attributes at parse time.
-    (active, extended_key_value_attributes, "1.50.0", Some(78835), None),
-
     /// Allows const generics to have default values (e.g. `struct Foo<const N: usize = 3>(...);`).
     (active, const_generics_defaults, "1.51.0", Some(44580), None),
 

compiler/rustc_hir/src/lib.rs

@@ -4,7 +4,7 @@
 
 #![feature(crate_visibility_modifier)]
 #![feature(const_panic)]
-#![feature(extended_key_value_attributes)]
+#![cfg_attr(bootstrap, feature(extended_key_value_attributes))]
 #![feature(in_band_lifetimes)]
 #![feature(once_cell)]
 #![cfg_attr(bootstrap, feature(or_patterns))]

compiler/rustc_parse/src/parser/mod.rs

@@ -1065,24 +1065,11 @@ impl<'a> Parser<'a> {
             } else if !delimited_only {
                 if self.eat(&token::Eq) {
                     let eq_span = self.prev_token.span;
-                    let mut is_interpolated_expr = false;
-                    if let token::Interpolated(nt) = &self.token.kind {
-                        if let token::NtExpr(..) = **nt {
-                            is_interpolated_expr = true;
-                        }
-                    }
 
                     // Collect tokens because they are used during lowering to HIR.
                     let expr = self.parse_expr_force_collect()?;
                     let span = expr.span;
 
-                    match &expr.kind {
-                        // Not gated to support things like `doc = $expr` that work on stable.
-                        _ if is_interpolated_expr => {}
-                        ExprKind::Lit(lit) if lit.kind.is_unsuffixed() => {}
-                        _ => self.sess.gated_spans.gate(sym::extended_key_value_attributes, span),
-                    }
-
                     let token_kind = token::Interpolated(Lrc::new(token::NtExpr(expr)));
                     MacArgs::Eq(eq_span, Token::new(token_kind, span))
                 } else {

compiler/rustc_symbol_mangling/src/v0.rs

@@ -485,9 +485,39 @@ impl Printer<'tcx> for SymbolMangler<'tcx> {
         mut self,
         predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
     ) -> Result<Self::DynExistential, Self::Error> {
-        for predicate in predicates {
-            self = self.in_binder(&predicate, |mut cx, predicate| {
-                match predicate {
+        // Okay, so this is a bit tricky. Imagine we have a trait object like
+        // `dyn for<'a> Foo<'a, Bar = &'a ()>`. When we mangle this, the
+        // output looks really close to the syntax, where the `Bar = &'a ()` bit
+        // is under the same binders (`['a]`) as the `Foo<'a>` bit. However, we
+        // actually desugar these into two separate `ExistentialPredicate`s. We
+        // can't enter/exit the "binder scope" twice though, because then we
+        // would mangle the binders twice. (Also, side note, we merging these
+        // two is kind of difficult, because of potential HRTBs in the Projection
+        // predicate.)
+        //
+        // Also worth mentioning: imagine that we instead had
+        // `dyn for<'a> Foo<'a, Bar = &'a ()> + Send`. In this case, `Send` is
+        // under the same binders as `Foo`. Currently, this doesn't matter,
+        // because only *auto traits* are allowed other than the principal trait
+        // and all auto traits don't have any generics. Two things could
+        // make this not an "okay" mangling:
+        // 1) Instead of mangling only *used*
+        // bound vars, we want to mangle *all* bound vars (`for<'b> Send` is a
+        // valid trait predicate);
+        // 2) We allow multiple "principal" traits in the future, or at least
+        // allow in any form another trait predicate that can take generics.
+        //
+        // Here we assume that predicates have the following structure:
+        // [<Trait> [{<Projection>}]] [{<Auto>}]
+        // Since any predicates after the first one shouldn't change the binders,
+        // just put them all in the binders of the first.
+        self = self.in_binder(&predicates[0], |mut cx, _| {
+            for predicate in predicates.iter() {
+                // It would be nice to be able to validate bound vars here, but
+                // projections can actually include bound vars from super traits
+                // because of HRTBs (only in the `Self` type). Also, auto traits
+                // could have different bound vars *anyways*.
+                match predicate.as_ref().skip_binder() {
                     ty::ExistentialPredicate::Trait(trait_ref) => {
                         // Use a type that can't appear in defaults of type parameters.
                         let dummy_self = cx.tcx.mk_ty_infer(ty::FreshTy(0));
@@ -504,9 +534,10 @@ impl Printer<'tcx> for SymbolMangler<'tcx> {
                         cx = cx.print_def_path(*def_id, &[])?;
                     }
                 }
-                Ok(cx)
-            })?;
-        }
+            }
+            Ok(cx)
+        })?;
+
         self.push("E");
         Ok(self)
     }

compiler/rustc_target/src/spec/windows_gnu_base.rs

@@ -66,6 +66,7 @@ pub fn opts() -> TargetOptions {
         // FIXME(#13846) this should be enabled for windows
         function_sections: false,
         linker: Some("gcc".to_string()),
+        linker_is_gnu: true,
         dynamic_linking: true,
         executables: true,
         dll_prefix: String::new(),