Rollup of 10 pull requests

compiler/rustc_ast/src/tokenstream.rs

@@ -26,7 +26,7 @@ use rustc_span::{sym, Span, Symbol, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 
 use std::borrow::Cow;
-use std::{cmp, fmt, iter, mem};
+use std::{cmp, fmt, iter};
 
 /// When the main Rust parser encounters a syntax-extension invocation, it
 /// parses the arguments to the invocation as a token tree. This is a very
@@ -81,14 +81,6 @@ impl TokenTree {
         }
     }
 
-    /// Modify the `TokenTree`'s span in-place.
-    pub fn set_span(&mut self, span: Span) {
-        match self {
-            TokenTree::Token(token, _) => token.span = span,
-            TokenTree::Delimited(dspan, ..) => *dspan = DelimSpan::from_single(span),
-        }
-    }
-
     /// Create a `TokenTree::Token` with alone spacing.
     pub fn token_alone(kind: TokenKind, span: Span) -> TokenTree {
         TokenTree::Token(Token::new(kind, span), Spacing::Alone)
@@ -461,19 +453,6 @@ impl TokenStream {
         t1.next().is_none() && t2.next().is_none()
     }
 
-    /// Applies the supplied function to each `TokenTree` and its index in `self`, returning a new `TokenStream`
-    ///
-    /// It is equivalent to `TokenStream::new(self.trees().cloned().enumerate().map(|(i, tt)| f(i, tt)).collect())`.
-    pub fn map_enumerated_owned(
-        mut self,
-        mut f: impl FnMut(usize, TokenTree) -> TokenTree,
-    ) -> TokenStream {
-        let owned = Lrc::make_mut(&mut self.0); // clone if necessary
-        // rely on vec's in-place optimizations to avoid another allocation
-        *owned = mem::take(owned).into_iter().enumerate().map(|(i, tree)| f(i, tree)).collect();
-        self
-    }
-
     /// Create a token stream containing a single token with alone spacing. The
     /// spacing used for the final token in a constructed stream doesn't matter
     /// because it's never used. In practice we arbitrarily use

compiler/rustc_ast_lowering/src/lib.rs

@@ -1434,19 +1434,21 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 let (bounds, lifetime_bound) = self.with_dyn_type_scope(true, |this| {
                     let bounds =
                         this.arena.alloc_from_iter(bounds.iter().filter_map(|bound| match bound {
-                            GenericBound::Trait(
-                                ty,
-                                TraitBoundModifiers {
-                                    polarity: BoundPolarity::Positive | BoundPolarity::Negative(_),
-                                    constness,
-                                },
-                            ) => Some(this.lower_poly_trait_ref(ty, itctx, *constness)),
-                            // We can safely ignore constness here, since AST validation
-                            // will take care of invalid modifier combinations.
-                            GenericBound::Trait(
-                                _,
-                                TraitBoundModifiers { polarity: BoundPolarity::Maybe(_), .. },
-                            ) => None,
+                            // We can safely ignore constness here since AST validation
+                            // takes care of rejecting invalid modifier combinations and
+                            // const trait bounds in trait object types.
+                            GenericBound::Trait(ty, modifiers) => match modifiers.polarity {
+                                BoundPolarity::Positive | BoundPolarity::Negative(_) => {
+                                    Some(this.lower_poly_trait_ref(
+                                        ty,
+                                        itctx,
+                                        // Still, don't pass along the constness here; we don't want to
+                                        // synthesize any host effect args, it'd only cause problems.
+                                        ast::BoundConstness::Never,
+                                    ))
+                                }
+                                BoundPolarity::Maybe(_) => None,
+                            },
                             GenericBound::Outlives(lifetime) => {
                                 if lifetime_bound.is_none() {
                                     lifetime_bound = Some(this.lower_lifetime(lifetime));

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1186,15 +1186,22 @@ mod win {
     }
 }
 
-fn add_sanitizer_libraries(sess: &Session, crate_type: CrateType, linker: &mut dyn Linker) {
-    // On macOS the runtimes are distributed as dylibs which should be linked to
-    // both executables and dynamic shared objects. Everywhere else the runtimes
-    // are currently distributed as static libraries which should be linked to
-    // executables only.
+fn add_sanitizer_libraries(
+    sess: &Session,
+    flavor: LinkerFlavor,
+    crate_type: CrateType,
+    linker: &mut dyn Linker,
+) {
+    // On macOS and Windows using MSVC the runtimes are distributed as dylibs
+    // which should be linked to both executables and dynamic libraries.
+    // Everywhere else the runtimes are currently distributed as static
+    // libraries which should be linked to executables only.
     let needs_runtime = !sess.target.is_like_android
         && match crate_type {
             CrateType::Executable => true,
-            CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro => sess.target.is_like_osx,
+            CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro => {
+                sess.target.is_like_osx || sess.target.is_like_msvc
+            }
             CrateType::Rlib | CrateType::Staticlib => false,
         };
 
@@ -1204,26 +1211,31 @@ fn add_sanitizer_libraries(sess: &Session, crate_type: CrateType, linker: &mut d
 
     let sanitizer = sess.opts.unstable_opts.sanitizer;
     if sanitizer.contains(SanitizerSet::ADDRESS) {
-        link_sanitizer_runtime(sess, linker, "asan");
+        link_sanitizer_runtime(sess, flavor, linker, "asan");
     }
     if sanitizer.contains(SanitizerSet::LEAK) {
-        link_sanitizer_runtime(sess, linker, "lsan");
+        link_sanitizer_runtime(sess, flavor, linker, "lsan");
     }
     if sanitizer.contains(SanitizerSet::MEMORY) {
-        link_sanitizer_runtime(sess, linker, "msan");
+        link_sanitizer_runtime(sess, flavor, linker, "msan");
     }
     if sanitizer.contains(SanitizerSet::THREAD) {
-        link_sanitizer_runtime(sess, linker, "tsan");
+        link_sanitizer_runtime(sess, flavor, linker, "tsan");
     }
     if sanitizer.contains(SanitizerSet::HWADDRESS) {
-        link_sanitizer_runtime(sess, linker, "hwasan");
+        link_sanitizer_runtime(sess, flavor, linker, "hwasan");
     }
     if sanitizer.contains(SanitizerSet::SAFESTACK) {
-        link_sanitizer_runtime(sess, linker, "safestack");
+        link_sanitizer_runtime(sess, flavor, linker, "safestack");
     }
 }
 
-fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {
+fn link_sanitizer_runtime(
+    sess: &Session,
+    flavor: LinkerFlavor,
+    linker: &mut dyn Linker,
+    name: &str,
+) {
     fn find_sanitizer_runtime(sess: &Session, filename: &str) -> PathBuf {
         let session_tlib =
             filesearch::make_target_lib_path(&sess.sysroot, sess.opts.target_triple.triple());
@@ -1254,6 +1266,10 @@ fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {
         let rpath = path.to_str().expect("non-utf8 component in path");
         linker.args(&["-Wl,-rpath", "-Xlinker", rpath]);
         linker.link_dylib(&filename, false, true);
+    } else if sess.target.is_like_msvc && flavor == LinkerFlavor::Msvc(Lld::No) && name == "asan" {
+        // MSVC provides the `/INFERASANLIBS` argument to automatically find the
+        // compatible ASAN library.
+        linker.arg("/INFERASANLIBS");
     } else {
         let filename = format!("librustc{channel}_rt.{name}.a");
         let path = find_sanitizer_runtime(sess, &filename).join(&filename);
@@ -2076,7 +2092,7 @@ fn linker_with_args<'a>(
     );
 
     // Sanitizer libraries.
-    add_sanitizer_libraries(sess, crate_type, cmd);
+    add_sanitizer_libraries(sess, flavor, crate_type, cmd);
 
     // Object code from the current crate.
     // Take careful note of the ordering of the arguments we pass to the linker

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -10,7 +10,7 @@ use crate::mbe::transcribe::transcribe;
 
 use rustc_ast as ast;
 use rustc_ast::token::{self, Delimiter, NonterminalKind, Token, TokenKind, TokenKind::*};
-use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree};
+use rustc_ast::tokenstream::{DelimSpan, TokenStream};
 use rustc_ast::{NodeId, DUMMY_NODE_ID};
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, TransparencyError};
@@ -213,45 +213,14 @@ fn expand_macro<'cx>(
             let arm_span = rhses[i].span();
 
             // rhs has holes ( `$id` and `$(...)` that need filled)
-            let mut tts = match transcribe(cx, &named_matches, rhs, rhs_span, transparency) {
+            let tts = match transcribe(cx, &named_matches, rhs, rhs_span, transparency) {
                 Ok(tts) => tts,
                 Err(mut err) => {
                     err.emit();
                     return DummyResult::any(arm_span);
                 }
             };
 
-            // Replace all the tokens for the corresponding positions in the macro, to maintain
-            // proper positions in error reporting, while maintaining the macro_backtrace.
-            if tts.len() == rhs.tts.len() {
-                tts = tts.map_enumerated_owned(|i, mut tt| {
-                    let rhs_tt = &rhs.tts[i];
-                    let ctxt = tt.span().ctxt();
-                    match (&mut tt, rhs_tt) {
-                        // preserve the delim spans if able
-                        (
-                            TokenTree::Delimited(target_sp, ..),
-                            mbe::TokenTree::Delimited(source_sp, ..),
-                        ) => {
-                            target_sp.open = source_sp.open.with_ctxt(ctxt);
-                            target_sp.close = source_sp.close.with_ctxt(ctxt);
-                        }
-                        (
-                            TokenTree::Delimited(target_sp, ..),
-                            mbe::TokenTree::MetaVar(source_sp, ..),
-                        ) => {
-                            target_sp.open = source_sp.with_ctxt(ctxt);
-                            target_sp.close = source_sp.with_ctxt(ctxt).shrink_to_hi();
-                        }
-                        _ => {
-                            let sp = rhs_tt.span().with_ctxt(ctxt);
-                            tt.set_span(sp);
-                        }
-                    }
-                    tt
-                });
-            }
-
             if cx.trace_macros() {
                 let msg = format!("to `{}`", pprust::tts_to_string(&tts));
                 trace_macros_note(&mut cx.expansions, sp, msg);

compiler/rustc_expand/src/mbe/transcribe.rs

@@ -4,7 +4,7 @@ use crate::errors::{
     NoSyntaxVarsExprRepeat, VarStillRepeating,
 };
 use crate::mbe::macro_parser::{MatchedNonterminal, MatchedSeq, MatchedTokenTree, NamedMatch};
-use crate::mbe::{self, MetaVarExpr};
+use crate::mbe::{self, KleeneOp, MetaVarExpr};
 use rustc_ast::mut_visit::{self, MutVisitor};
 use rustc_ast::token::{self, Delimiter, Token, TokenKind};
 use rustc_ast::tokenstream::{DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree};
@@ -42,6 +42,7 @@ enum Frame<'a> {
         tts: &'a [mbe::TokenTree],
         idx: usize,
         sep: Option<Token>,
+        kleene_op: KleeneOp,
     },
 }
 
@@ -207,7 +208,7 @@ pub(super) fn transcribe<'a>(
 
                         // Is the repetition empty?
                         if len == 0 {
-                            if seq.kleene.op == mbe::KleeneOp::OneOrMore {
+                            if seq.kleene.op == KleeneOp::OneOrMore {
                                 // FIXME: this really ought to be caught at macro definition
                                 // time... It happens when the Kleene operator in the matcher and
                                 // the body for the same meta-variable do not match.
@@ -227,6 +228,7 @@ pub(super) fn transcribe<'a>(
                                 idx: 0,
                                 sep: seq.separator.clone(),
                                 tts: &delimited.tts,
+                                kleene_op: seq.kleene.op,
                             });
                         }
                     }
@@ -243,7 +245,7 @@ pub(super) fn transcribe<'a>(
                         MatchedTokenTree(tt) => {
                             // `tt`s are emitted into the output stream directly as "raw tokens",
                             // without wrapping them into groups.
-                            result.push(tt.clone());
+                            result.push(maybe_use_metavar_location(cx, &stack, sp, tt));
                         }
                         MatchedNonterminal(nt) => {
                             // Other variables are emitted into the output stream as groups with
@@ -308,6 +310,62 @@ pub(super) fn transcribe<'a>(
     }
 }
 
+/// Usually metavariables `$var` produce interpolated tokens, which have an additional place for
+/// keeping both the original span and the metavariable span. For `tt` metavariables that's not the
+/// case however, and there's no place for keeping a second span. So we try to give the single
+/// produced span a location that would be most useful in practice (the hygiene part of the span
+/// must not be changed).
+///
+/// Different locations are useful for different purposes:
+/// - The original location is useful when we need to report a diagnostic for the original token in
+///   isolation, without combining it with any surrounding tokens. This case occurs, but it is not
+///   very common in practice.
+/// - The metavariable location is useful when we need to somehow combine the token span with spans
+///   of its surrounding tokens. This is the most common way to use token spans.
+///
+/// So this function replaces the original location with the metavariable location in all cases
+/// except these two:
+/// - The metavariable is an element of undelimited sequence `$($tt)*`.
+///   These are typically used for passing larger amounts of code, and tokens in that code usually
+///   combine with each other and not with tokens outside of the sequence.
+/// - The metavariable span comes from a different crate, then we prefer the more local span.
+///
+/// FIXME: Find a way to keep both original and metavariable spans for all tokens without
+/// regressing compilation time too much. Several experiments for adding such spans were made in
+/// the past (PR #95580, #118517, #118671) and all showed some regressions.
+fn maybe_use_metavar_location(
+    cx: &ExtCtxt<'_>,
+    stack: &[Frame<'_>],
+    metavar_span: Span,
+    orig_tt: &TokenTree,
+) -> TokenTree {
+    let undelimited_seq = matches!(
+        stack.last(),
+        Some(Frame::Sequence {
+            tts: [_],
+            sep: None,
+            kleene_op: KleeneOp::ZeroOrMore | KleeneOp::OneOrMore,
+            ..
+        })
+    );
+    if undelimited_seq || cx.source_map().is_imported(metavar_span) {
+        return orig_tt.clone();
+    }
+
+    match orig_tt {
+        TokenTree::Token(Token { kind, span }, spacing) => {
+            let span = metavar_span.with_ctxt(span.ctxt());
+            TokenTree::Token(Token { kind: kind.clone(), span }, *spacing)
+        }
+        TokenTree::Delimited(dspan, dspacing, delimiter, tts) => {
+            let open = metavar_span.shrink_to_lo().with_ctxt(dspan.open.ctxt());
+            let close = metavar_span.shrink_to_hi().with_ctxt(dspan.close.ctxt());
+            let dspan = DelimSpan::from_pair(open, close);
+            TokenTree::Delimited(dspan, *dspacing, *delimiter, tts.clone())
+        }
+    }
+}
+
 /// Lookup the meta-var named `ident` and return the matched token tree from the invocation using
 /// the set of matches `interpolations`.
 ///