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path: root/compiler/rustc_attr_parsing/src/parser.rs
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Diffstat (limited to 'compiler/rustc_attr_parsing/src/parser.rs')
-rw-r--r--compiler/rustc_attr_parsing/src/parser.rs92
1 files changed, 54 insertions, 38 deletions
diff --git a/compiler/rustc_attr_parsing/src/parser.rs b/compiler/rustc_attr_parsing/src/parser.rs
index 364f8819d13..4f903594225 100644
--- a/compiler/rustc_attr_parsing/src/parser.rs
+++ b/compiler/rustc_attr_parsing/src/parser.rs
@@ -10,11 +10,11 @@ use rustc_ast::token::{self, Delimiter, MetaVarKind};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::{AttrArgs, DelimArgs, Expr, ExprKind, LitKind, MetaItemLit, NormalAttr, Path};
 use rustc_ast_pretty::pprust;
-use rustc_errors::PResult;
+use rustc_errors::{Diag, PResult};
 use rustc_hir::{self as hir, AttrPath};
 use rustc_parse::exp;
 use rustc_parse::parser::{Parser, PathStyle, token_descr};
-use rustc_session::errors::report_lit_error;
+use rustc_session::errors::{create_lit_error, report_lit_error};
 use rustc_session::parse::ParseSess;
 use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, sym};
 use thin_vec::ThinVec;
@@ -328,15 +328,16 @@ fn expr_to_lit(
         match res {
             Ok(lit) => {
                 if token_lit.suffix.is_some() {
-                    psess
-                        .dcx()
-                        .create_err(SuffixedLiteralInAttribute { span: lit.span })
-                        .emit_unless_delay(!should_emit.should_emit());
+                    should_emit.emit_err(
+                        psess.dcx().create_err(SuffixedLiteralInAttribute { span: lit.span }),
+                    );
                     None
                 } else {
-                    if should_emit.should_emit() && !lit.kind.is_unsuffixed() {
+                    if !lit.kind.is_unsuffixed() {
                         // Emit error and continue, we can still parse the attribute as if the suffix isn't there
-                        psess.dcx().emit_err(SuffixedLiteralInAttribute { span: lit.span });
+                        should_emit.emit_err(
+                            psess.dcx().create_err(SuffixedLiteralInAttribute { span: lit.span }),
+                        );
                     }
 
                     Some(lit)
@@ -354,6 +355,10 @@ fn expr_to_lit(
             }
         }
     } else {
+        if matches!(should_emit, ShouldEmit::Nothing) {
+            return None;
+        }
+
         // Example cases:
         // - `#[foo = 1+1]`: results in `ast::ExprKind::BinOp`.
         // - `#[foo = include_str!("nonexistent-file.rs")]`:
@@ -361,12 +366,8 @@ fn expr_to_lit(
         //   the error because an earlier error will have already
         //   been reported.
         let msg = "attribute value must be a literal";
-        let mut err = psess.dcx().struct_span_err(span, msg);
-        if let ExprKind::Err(_) = expr.kind {
-            err.downgrade_to_delayed_bug();
-        }
-
-        err.emit_unless_delay(!should_emit.should_emit());
+        let err = psess.dcx().struct_span_err(span, msg);
+        should_emit.emit_err(err);
         None
     }
 }
@@ -378,28 +379,31 @@ struct MetaItemListParserContext<'a, 'sess> {
 
 impl<'a, 'sess> MetaItemListParserContext<'a, 'sess> {
     fn parse_unsuffixed_meta_item_lit(&mut self) -> PResult<'sess, MetaItemLit> {
-        let uninterpolated_span = self.parser.token_uninterpolated_span();
-        let Some(token_lit) = self.parser.eat_token_lit() else {
-            return self.parser.handle_missing_lit(Parser::mk_meta_item_lit_char);
-        };
+        let Some(token_lit) = self.parser.eat_token_lit() else { return Err(self.expected_lit()) };
+        self.unsuffixed_meta_item_from_lit(token_lit)
+    }
 
+    fn unsuffixed_meta_item_from_lit(
+        &mut self,
+        token_lit: token::Lit,
+    ) -> PResult<'sess, MetaItemLit> {
         let lit = match MetaItemLit::from_token_lit(token_lit, self.parser.prev_token.span) {
             Ok(lit) => lit,
             Err(err) => {
-                let guar =
-                    report_lit_error(&self.parser.psess, err, token_lit, uninterpolated_span);
-                // Pack possible quotes and prefixes from the original literal into
-                // the error literal's symbol so they can be pretty-printed faithfully.
-                let suffixless_lit = token::Lit::new(token_lit.kind, token_lit.symbol, None);
-                let symbol = Symbol::intern(&suffixless_lit.to_string());
-                let token_lit = token::Lit::new(token::Err(guar), symbol, token_lit.suffix);
-                MetaItemLit::from_token_lit(token_lit, uninterpolated_span).unwrap()
+                return Err(create_lit_error(
+                    &self.parser.psess,
+                    err,
+                    token_lit,
+                    self.parser.prev_token_uninterpolated_span(),
+                ));
             }
         };
 
-        if self.should_emit.should_emit() && !lit.kind.is_unsuffixed() {
+        if !lit.kind.is_unsuffixed() {
             // Emit error and continue, we can still parse the attribute as if the suffix isn't there
-            self.parser.dcx().emit_err(SuffixedLiteralInAttribute { span: lit.span });
+            self.should_emit.emit_err(
+                self.parser.dcx().create_err(SuffixedLiteralInAttribute { span: lit.span }),
+            );
         }
 
         Ok(lit)
@@ -445,16 +449,28 @@ impl<'a, 'sess> MetaItemListParserContext<'a, 'sess> {
     }
 
     fn parse_meta_item_inner(&mut self) -> PResult<'sess, MetaItemOrLitParser<'static>> {
-        match self.parse_unsuffixed_meta_item_lit() {
-            Ok(lit) => return Ok(MetaItemOrLitParser::Lit(lit)),
-            Err(err) => err.cancel(), // we provide a better error below
-        }
-
-        match self.parse_attr_item() {
-            Ok(mi) => return Ok(MetaItemOrLitParser::MetaItemParser(mi)),
-            Err(err) => err.cancel(), // we provide a better error below
+        if let Some(token_lit) = self.parser.eat_token_lit() {
+            // If a literal token is parsed, we commit to parsing a MetaItemLit for better errors
+            Ok(MetaItemOrLitParser::Lit(self.unsuffixed_meta_item_from_lit(token_lit)?))
+        } else {
+            let prev_pros = self.parser.approx_token_stream_pos();
+            match self.parse_attr_item() {
+                Ok(item) => Ok(MetaItemOrLitParser::MetaItemParser(item)),
+                Err(err) => {
+                    // If `parse_attr_item` made any progress, it likely has a more precise error we should prefer
+                    // If it didn't make progress we use the `expected_lit` from below
+                    if self.parser.approx_token_stream_pos() != prev_pros {
+                        Err(err)
+                    } else {
+                        err.cancel();
+                        Err(self.expected_lit())
+                    }
+                }
+            }
         }
+    }
 
+    fn expected_lit(&mut self) -> Diag<'sess> {
         let mut err = InvalidMetaItem {
             span: self.parser.token.span,
             descr: token_descr(&self.parser.token),
@@ -489,7 +505,7 @@ impl<'a, 'sess> MetaItemListParserContext<'a, 'sess> {
             self.parser.bump();
         }
 
-        Err(self.parser.dcx().create_err(err))
+        self.parser.dcx().create_err(err)
     }
 
     fn parse(
@@ -539,7 +555,7 @@ impl<'a> MetaItemListParser<'a> {
         ) {
             Ok(s) => Some(s),
             Err(e) => {
-                e.emit_unless_delay(!should_emit.should_emit());
+                should_emit.emit_err(e);
                 None
             }
         }