Merging upstream version 1.72.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 147 insertions, 55 deletions

diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 4671adccc..8a251ea29 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -947,6 +947,8 @@ pub trait ResolverExpand {
     /// HIR proc macros items back to their harness items.
     fn declare_proc_macro(&mut self, id: NodeId);
 
+    fn append_stripped_cfg_item(&mut self, parent_node: NodeId, name: Ident, cfg: ast::MetaItem);
+
     /// Tools registered with `#![register_tool]` and used by tool attributes and lints.
     fn registered_tools(&self) -> &RegisteredTools;
 }
@@ -965,7 +967,7 @@ pub trait LintStoreExpand {
 
 type LintStoreExpandDyn<'a> = Option<&'a (dyn LintStoreExpand + 'a)>;
 
-#[derive(Clone, Default)]
+#[derive(Debug, Clone, Default)]
 pub struct ModuleData {
     /// Path to the module starting from the crate name, like `my_crate::foo::bar`.
     pub mod_path: Vec<Ident>,
@@ -1108,6 +1110,7 @@ impl<'a> ExtCtxt<'a> {
     }
 
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_span_err<S: Into<MultiSpan>>(
         &self,
         sp: S,
@@ -1116,6 +1119,7 @@ impl<'a> ExtCtxt<'a> {
         self.sess.parse_sess.span_diagnostic.struct_span_err(sp, msg)
     }
 
+    #[track_caller]
     pub fn create_err(
         &self,
         err: impl IntoDiagnostic<'a>,
@@ -1123,6 +1127,7 @@ impl<'a> ExtCtxt<'a> {
         self.sess.create_err(err)
     }
 
+    #[track_caller]
     pub fn emit_err(&self, err: impl IntoDiagnostic<'a>) -> ErrorGuaranteed {
         self.sess.emit_err(err)
     }
@@ -1133,10 +1138,12 @@ impl<'a> ExtCtxt<'a> {
     /// Compilation will be stopped in the near future (at the end of
     /// the macro expansion phase).
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) {
         self.sess.parse_sess.span_diagnostic.span_err(sp, msg);
     }
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) {
         self.sess.parse_sess.span_diagnostic.span_warn(sp, msg);
     }
@@ -1154,7 +1161,7 @@ impl<'a> ExtCtxt<'a> {
         // Fixme: does this result in errors?
         self.expansions.clear();
     }
-    pub fn bug(&self, msg: &str) -> ! {
+    pub fn bug(&self, msg: &'static str) -> ! {
         self.sess.parse_sess.span_diagnostic.bug(msg);
     }
     pub fn trace_macros(&self) -> bool {
@@ -1224,7 +1231,7 @@ pub fn resolve_path(
 pub fn expr_to_spanned_string<'a>(
     cx: &'a mut ExtCtxt<'_>,
     expr: P<ast::Expr>,
-    err_msg: &str,
+    err_msg: &'static str,
 ) -> Result<(Symbol, ast::StrStyle, Span), Option<(DiagnosticBuilder<'a, ErrorGuaranteed>, bool)>> {
     // Perform eager expansion on the expression.
     // We want to be able to handle e.g., `concat!("foo", "bar")`.
@@ -1262,7 +1269,7 @@ pub fn expr_to_spanned_string<'a>(
 pub fn expr_to_string(
     cx: &mut ExtCtxt<'_>,
     expr: P<ast::Expr>,
-    err_msg: &str,
+    err_msg: &'static str,
 ) -> Option<(Symbol, ast::StrStyle)> {
     expr_to_spanned_string(cx, expr, err_msg)
         .map_err(|err| {
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 4ff8e409d..3e43eae00 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -197,9 +197,11 @@ pub fn pre_configure_attrs(sess: &Session, attrs: &[Attribute]) -> ast::AttrVec
         config_tokens: false,
         lint_node_id: ast::CRATE_NODE_ID,
     };
-    let attrs: ast::AttrVec =
-        attrs.iter().flat_map(|attr| strip_unconfigured.process_cfg_attr(attr)).collect();
-    if strip_unconfigured.in_cfg(&attrs) { attrs } else { ast::AttrVec::new() }
+    attrs
+        .iter()
+        .flat_map(|attr| strip_unconfigured.process_cfg_attr(attr))
+        .take_while(|attr| !is_cfg(attr) || strip_unconfigured.cfg_true(attr).0)
+        .collect()
 }
 
 #[macro_export]
@@ -416,26 +418,34 @@ impl<'a> StripUnconfigured<'a> {
 
     /// Determines if a node with the given attributes should be included in this configuration.
     fn in_cfg(&self, attrs: &[Attribute]) -> bool {
-        attrs.iter().all(|attr| !is_cfg(attr) || self.cfg_true(attr))
+        attrs.iter().all(|attr| !is_cfg(attr) || self.cfg_true(attr).0)
     }
 
-    pub(crate) fn cfg_true(&self, attr: &Attribute) -> bool {
+    pub(crate) fn cfg_true(&self, attr: &Attribute) -> (bool, Option<MetaItem>) {
         let meta_item = match validate_attr::parse_meta(&self.sess.parse_sess, attr) {
             Ok(meta_item) => meta_item,
             Err(mut err) => {
                 err.emit();
-                return true;
+                return (true, None);
             }
         };
-        parse_cfg(&meta_item, &self.sess).map_or(true, |meta_item| {
-            attr::cfg_matches(&meta_item, &self.sess.parse_sess, self.lint_node_id, self.features)
-        })
+        (
+            parse_cfg(&meta_item, &self.sess).map_or(true, |meta_item| {
+                attr::cfg_matches(
+                    &meta_item,
+                    &self.sess.parse_sess,
+                    self.lint_node_id,
+                    self.features,
+                )
+            }),
+            Some(meta_item),
+        )
     }
 
     /// If attributes are not allowed on expressions, emit an error for `attr`
     #[instrument(level = "trace", skip(self))]
     pub(crate) fn maybe_emit_expr_attr_err(&self, attr: &Attribute) {
-        if !self.features.map_or(true, |features| features.stmt_expr_attributes) {
+        if self.features.is_some_and(|features| !features.stmt_expr_attributes) {
             let mut err = feature_err(
                 &self.sess.parse_sess,
                 sym::stmt_expr_attributes,
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index ce0093c7d..9850723a8 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -1039,9 +1039,20 @@ trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
     ) -> Result<Self::OutputTy, Self> {
         Ok(noop_flat_map(node, collector))
     }
-    fn expand_cfg_false(&mut self, collector: &mut InvocationCollector<'_, '_>, span: Span) {
+    fn expand_cfg_false(
+        &mut self,
+        collector: &mut InvocationCollector<'_, '_>,
+        _pos: usize,
+        span: Span,
+    ) {
         collector.cx.emit_err(RemoveNodeNotSupported { span, descr: Self::descr() });
     }
+
+    /// All of the names (items) declared by this node.
+    /// This is an approximation and should only be used for diagnostics.
+    fn declared_names(&self) -> Vec<Ident> {
+        vec![]
+    }
 }
 
 impl InvocationCollectorNode for P<ast::Item> {
@@ -1148,6 +1159,27 @@ impl InvocationCollectorNode for P<ast::Item> {
         collector.cx.current_expansion.module = orig_module;
         res
     }
+    fn declared_names(&self) -> Vec<Ident> {
+        if let ItemKind::Use(ut) = &self.kind {
+            fn collect_use_tree_leaves(ut: &ast::UseTree, idents: &mut Vec<Ident>) {
+                match &ut.kind {
+                    ast::UseTreeKind::Glob => {}
+                    ast::UseTreeKind::Simple(_) => idents.push(ut.ident()),
+                    ast::UseTreeKind::Nested(nested) => {
+                        for (ut, _) in nested {
+                            collect_use_tree_leaves(&ut, idents);
+                        }
+                    }
+                }
+            }
+
+            let mut idents = Vec::new();
+            collect_use_tree_leaves(&ut, &mut idents);
+            return idents;
+        }
+
+        vec![self.ident]
+    }
 }
 
 struct TraitItemTag;
@@ -1382,8 +1414,15 @@ impl InvocationCollectorNode for ast::Crate {
     fn noop_visit<V: MutVisitor>(&mut self, visitor: &mut V) {
         noop_visit_crate(self, visitor)
     }
-    fn expand_cfg_false(&mut self, collector: &mut InvocationCollector<'_, '_>, _span: Span) {
-        self.attrs.clear();
+    fn expand_cfg_false(
+        &mut self,
+        collector: &mut InvocationCollector<'_, '_>,
+        pos: usize,
+        _span: Span,
+    ) {
+        // Attributes above `cfg(FALSE)` are left in place, because we may want to configure
+        // some global crate properties even on fully unconfigured crates.
+        self.attrs.truncate(pos);
         // Standard prelude imports are left in the crate for backward compatibility.
         self.items.truncate(collector.cx.num_standard_library_imports);
     }
@@ -1685,8 +1724,8 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
         node: &mut impl HasAttrs,
         attr: ast::Attribute,
         pos: usize,
-    ) -> bool {
-        let res = self.cfg().cfg_true(&attr);
+    ) -> (bool, Option<ast::MetaItem>) {
+        let (res, meta_item) = self.cfg().cfg_true(&attr);
         if res {
             // FIXME: `cfg(TRUE)` attributes do not currently remove themselves during expansion,
             // and some tools like rustdoc and clippy rely on that. Find a way to remove them
@@ -1694,7 +1733,8 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
             self.cx.expanded_inert_attrs.mark(&attr);
             node.visit_attrs(|attrs| attrs.insert(pos, attr));
         }
-        res
+
+        (res, meta_item)
     }
 
     fn expand_cfg_attr(&self, node: &mut impl HasAttrs, attr: &ast::Attribute, pos: usize) {
@@ -1715,9 +1755,20 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
             return match self.take_first_attr(&mut node) {
                 Some((attr, pos, derives)) => match attr.name_or_empty() {
                     sym::cfg => {
-                        if self.expand_cfg_true(&mut node, attr, pos) {
+                        let (res, meta_item) = self.expand_cfg_true(&mut node, attr, pos);
+                        if res {
                             continue;
                         }
+
+                        if let Some(meta_item) = meta_item {
+                            for name in node.declared_names() {
+                                self.cx.resolver.append_stripped_cfg_item(
+                                    self.cx.current_expansion.lint_node_id,
+                                    name,
+                                    meta_item.clone(),
+                                )
+                            }
+                        }
                         Default::default()
                     }
                     sym::cfg_attr => {
@@ -1761,11 +1812,11 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
                 Some((attr, pos, derives)) => match attr.name_or_empty() {
                     sym::cfg => {
                         let span = attr.span;
-                        if self.expand_cfg_true(node, attr, pos) {
+                        if self.expand_cfg_true(node, attr, pos).0 {
                             continue;
                         }
 
-                        node.expand_cfg_false(self, span);
+                        node.expand_cfg_false(self, pos, span);
                         continue;
                     }
                     sym::cfg_attr => {
diff --git a/compiler/rustc_expand/src/mbe/diagnostics.rs b/compiler/rustc_expand/src/mbe/diagnostics.rs
index cb8b4899e..3593bed2d 100644
--- a/compiler/rustc_expand/src/mbe/diagnostics.rs
+++ b/compiler/rustc_expand/src/mbe/diagnostics.rs
@@ -170,7 +170,7 @@ impl<'a, 'cx, 'matcher> Tracker<'matcher> for CollectTrackerAndEmitter<'a, 'cx,
             }
             Error(err_sp, msg) => {
                 let span = err_sp.substitute_dummy(self.root_span);
-                self.cx.struct_span_err(span, msg.as_str()).emit();
+                self.cx.struct_span_err(span, msg.clone()).emit();
                 self.result = Some(DummyResult::any(span));
             }
             ErrorReported(_) => self.result = Some(DummyResult::any(self.root_span)),
@@ -222,7 +222,7 @@ pub(super) fn emit_frag_parse_err(
     {
         let msg = &e.message[0];
         e.message[0] = (
-            DiagnosticMessage::Str(format!(
+            DiagnosticMessage::from(format!(
                 "macro expansion ends with an incomplete expression: {}",
                 message.replace(", found `<eof>`", ""),
             )),
@@ -313,9 +313,9 @@ pub(super) fn annotate_doc_comment(err: &mut Diagnostic, sm: &SourceMap, span: S
 
 /// Generates an appropriate parsing failure message. For EOF, this is "unexpected end...". For
 /// other tokens, this is "unexpected token...".
-pub(super) fn parse_failure_msg(tok: &Token) -> String {
+pub(super) fn parse_failure_msg(tok: &Token) -> Cow<'static, str> {
     match tok.kind {
-        token::Eof => "unexpected end of macro invocation".to_string(),
-        _ => format!("no rules expected the token `{}`", pprust::token_to_string(tok),),
+        token::Eof => Cow::from("unexpected end of macro invocation"),
+        _ => Cow::from(format!("no rules expected the token `{}`", pprust::token_to_string(tok))),
     }
 }
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs
index 1c222fb4a..f0e67cfd5 100644
--- a/compiler/rustc_expand/src/mbe/macro_parser.rs
+++ b/compiler/rustc_expand/src/mbe/macro_parser.rs
@@ -249,6 +249,7 @@ pub(super) fn compute_locs(matcher: &[TokenTree]) -> Vec<MatcherLoc> {
 }
 
 /// A single matcher position, representing the state of matching.
+#[derive(Debug)]
 struct MatcherPos {
     /// The index into `TtParser::locs`, which represents the "dot".
     idx: usize,
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index e4c65a204..42cc0a6b1 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -223,8 +223,7 @@ fn expand_macro<'cx>(
             // 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(|i, tt| {
-                    let mut tt = tt.clone();
+                tts = tts.map_enumerated_owned(|i, mut tt| {
                     let rhs_tt = &rhs.tts[i];
                     let ctxt = tt.span().ctxt();
                     match (&mut tt, rhs_tt) {
@@ -535,7 +534,7 @@ pub fn compile_declarative_macro(
                     .pop()
                     .unwrap();
                 }
-                sess.parse_sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
+                sess.parse_sess.span_diagnostic.span_bug(def.span, "wrong-structured rhs")
             })
             .collect::<Vec<mbe::TokenTree>>(),
         _ => sess.parse_sess.span_diagnostic.span_bug(def.span, "wrong-structured rhs"),
@@ -628,6 +627,40 @@ fn check_lhs_nt_follows(sess: &ParseSess, def: &ast::Item, lhs: &mbe::TokenTree)
     // after parsing/expansion. we can report every error in every macro this way.
 }
 
+fn is_empty_token_tree(sess: &ParseSess, seq: &mbe::SequenceRepetition) -> bool {
+    if seq.separator.is_some() {
+        false
+    } else {
+        let mut is_empty = true;
+        let mut iter = seq.tts.iter().peekable();
+        while let Some(tt) = iter.next() {
+            match tt {
+                mbe::TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Vis)) => {}
+                mbe::TokenTree::Token(t @ Token { kind: DocComment(..), .. }) => {
+                    let mut now = t;
+                    while let Some(&mbe::TokenTree::Token(
+                        next @ Token { kind: DocComment(..), .. },
+                    )) = iter.peek()
+                    {
+                        now = next;
+                        iter.next();
+                    }
+                    let span = t.span.to(now.span);
+                    sess.span_diagnostic.span_note_without_error(
+                        span,
+                        "doc comments are ignored in matcher position",
+                    );
+                }
+                mbe::TokenTree::Sequence(_, sub_seq)
+                    if (sub_seq.kleene.op == mbe::KleeneOp::ZeroOrMore
+                        || sub_seq.kleene.op == mbe::KleeneOp::ZeroOrOne) => {}
+                _ => is_empty = false,
+            }
+        }
+        is_empty
+    }
+}
+
 /// Checks that the lhs contains no repetition which could match an empty token
 /// tree, because then the matcher would hang indefinitely.
 fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[mbe::TokenTree]) -> bool {
@@ -644,16 +677,7 @@ fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[mbe::TokenTree]) -> bool {
                 }
             }
             TokenTree::Sequence(span, seq) => {
-                if seq.separator.is_none()
-                    && seq.tts.iter().all(|seq_tt| match seq_tt {
-                        TokenTree::MetaVarDecl(_, _, Some(NonterminalKind::Vis)) => true,
-                        TokenTree::Sequence(_, sub_seq) => {
-                            sub_seq.kleene.op == mbe::KleeneOp::ZeroOrMore
-                                || sub_seq.kleene.op == mbe::KleeneOp::ZeroOrOne
-                        }
-                        _ => false,
-                    })
-                {
+                if is_empty_token_tree(sess, seq) {
                     let sp = span.entire();
                     sess.span_diagnostic.span_err(sp, "repetition matches empty token tree");
                     return false;
diff --git a/compiler/rustc_expand/src/mbe/quoted.rs b/compiler/rustc_expand/src/mbe/quoted.rs
index b2bdf9c7e..40bfa3715 100644
--- a/compiler/rustc_expand/src/mbe/quoted.rs
+++ b/compiler/rustc_expand/src/mbe/quoted.rs
@@ -9,7 +9,7 @@ use rustc_session::parse::{feature_err, ParseSess};
 use rustc_span::symbol::{kw, sym, Ident};
 
 use rustc_span::edition::Edition;
-use rustc_span::{Span, SyntaxContext};
+use rustc_span::Span;
 
 const VALID_FRAGMENT_NAMES_MSG: &str = "valid fragment specifiers are \
                                         `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, \
@@ -72,7 +72,7 @@ pub(super) fn parse(
                                             // `SyntaxContext::root()` from a foreign crate will
                                             // have the edition of that crate (which we manually
                                             // retrieve via the `edition` parameter).
-                                            if span.ctxt() == SyntaxContext::root() {
+                                            if span.ctxt().is_root() {
                                                 edition
                                             } else {
                                                 span.edition()
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 891e84a2f..ecd231511 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -2,7 +2,7 @@ use crate::base::ExtCtxt;
 use pm::bridge::{
     server, DelimSpan, Diagnostic, ExpnGlobals, Group, Ident, LitKind, Literal, Punct, TokenTree,
 };
-use pm::{Delimiter, Level, LineColumn};
+use pm::{Delimiter, Level};
 use rustc_ast as ast;
 use rustc_ast::token;
 use rustc_ast::tokenstream::{self, Spacing::*, TokenStream};
@@ -648,23 +648,22 @@ impl server::Span for Rustc<'_, '_> {
 
         Range { start: relative_start_pos.0 as usize, end: relative_end_pos.0 as usize }
     }
-
-    fn start(&mut self, span: Self::Span) -> LineColumn {
-        let loc = self.sess().source_map().lookup_char_pos(span.lo());
-        LineColumn { line: loc.line, column: loc.col.to_usize() }
+    fn start(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_lo()
     }
 
-    fn end(&mut self, span: Self::Span) -> LineColumn {
-        let loc = self.sess().source_map().lookup_char_pos(span.hi());
-        LineColumn { line: loc.line, column: loc.col.to_usize() }
+    fn end(&mut self, span: Self::Span) -> Self::Span {
+        span.shrink_to_hi()
     }
 
-    fn before(&mut self, span: Self::Span) -> Self::Span {
-        span.shrink_to_lo()
+    fn line(&mut self, span: Self::Span) -> usize {
+        let loc = self.sess().source_map().lookup_char_pos(span.lo());
+        loc.line
     }
 
-    fn after(&mut self, span: Self::Span) -> Self::Span {
-        span.shrink_to_hi()
+    fn column(&mut self, span: Self::Span) -> usize {
+        let loc = self.sess().source_map().lookup_char_pos(span.lo());
+        loc.col.to_usize() + 1
     }
 
     fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {