Merge pull request #2293 from jieyouxu/rustc-pull

Rustc pull

4 files changed, 25 insertions, 7 deletions

diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 1d17290e1c7..4a3fda86c86 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -1,12 +1,12 @@
 use std::ops::Range;
 
+use literal_escaper::{self, EscapeError, Mode};
 use rustc_ast::ast::{self, AttrStyle};
 use rustc_ast::token::{self, CommentKind, Delimiter, IdentIsRaw, Token, TokenKind};
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast::util::unicode::contains_text_flow_control_chars;
 use rustc_errors::codes::*;
 use rustc_errors::{Applicability, Diag, DiagCtxtHandle, StashKey};
-use rustc_lexer::unescape::{self, EscapeError, Mode};
 use rustc_lexer::{Base, Cursor, DocStyle, LiteralKind, RawStrError};
 use rustc_session::lint::BuiltinLintDiag;
 use rustc_session::lint::builtin::{
@@ -970,7 +970,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         postfix_len: u32,
     ) -> (token::LitKind, Symbol) {
         self.cook_common(kind, mode, start, end, prefix_len, postfix_len, |src, mode, callback| {
-            unescape::unescape_unicode(src, mode, &mut |span, result| {
+            literal_escaper::unescape_unicode(src, mode, &mut |span, result| {
                 callback(span, result.map(drop))
             })
         })
@@ -986,7 +986,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         postfix_len: u32,
     ) -> (token::LitKind, Symbol) {
         self.cook_common(kind, mode, start, end, prefix_len, postfix_len, |src, mode, callback| {
-            unescape::unescape_mixed(src, mode, &mut |span, result| {
+            literal_escaper::unescape_mixed(src, mode, &mut |span, result| {
                 callback(span, result.map(drop))
             })
         })
diff --git a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
index 2e066f0179c..e8aa400e73d 100644
--- a/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
+++ b/compiler/rustc_parse/src/lexer/unescape_error_reporting.rs
@@ -3,8 +3,8 @@
 use std::iter::once;
 use std::ops::Range;
 
+use literal_escaper::{EscapeError, Mode};
 use rustc_errors::{Applicability, DiagCtxtHandle, ErrorGuaranteed};
-use rustc_lexer::unescape::{EscapeError, Mode};
 use rustc_span::{BytePos, Span};
 use tracing::debug;
 
diff --git a/compiler/rustc_parse/src/parser/attr.rs b/compiler/rustc_parse/src/parser/attr.rs
index 066b570c23f..53614049f08 100644
--- a/compiler/rustc_parse/src/parser/attr.rs
+++ b/compiler/rustc_parse/src/parser/attr.rs
@@ -127,12 +127,29 @@ impl<'a> Parser<'a> {
         let lo = self.token.span;
         // Attributes can't have attributes of their own [Editor's note: not with that attitude]
         self.collect_tokens_no_attrs(|this| {
+            let pound_hi = this.token.span.hi();
             assert!(this.eat(exp!(Pound)), "parse_attribute called in non-attribute position");
 
+            let not_lo = this.token.span.lo();
             let style =
                 if this.eat(exp!(Bang)) { ast::AttrStyle::Inner } else { ast::AttrStyle::Outer };
 
-            this.expect(exp!(OpenBracket))?;
+            let mut bracket_res = this.expect(exp!(OpenBracket));
+            // If `#!` is not followed by `[`
+            if let Err(err) = &mut bracket_res
+                && style == ast::AttrStyle::Inner
+                && pound_hi == not_lo
+            {
+                err.note(
+                    "the token sequence `#!` here looks like the start of \
+                    a shebang interpreter directive but it is not",
+                );
+                err.help(
+                    "if you meant this to be a shebang interpreter directive, \
+                    move it to the very start of the file",
+                );
+            }
+            bracket_res?;
             let item = this.parse_attr_item(ForceCollect::No)?;
             this.expect(exp!(CloseBracket))?;
             let attr_sp = lo.to(this.prev_token.span);
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 9b2d562a69e..85d94400b1c 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -6,6 +6,7 @@ use core::ops::{Bound, ControlFlow};
 use ast::mut_visit::{self, MutVisitor};
 use ast::token::{IdentIsRaw, MetaVarKind};
 use ast::{CoroutineKind, ForLoopKind, GenBlockKind, MatchKind, Pat, Path, PathSegment, Recovered};
+use literal_escaper::unescape_char;
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, Delimiter, Token, TokenKind};
 use rustc_ast::tokenstream::TokenTree;
@@ -21,7 +22,6 @@ use rustc_ast::{
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{Applicability, Diag, PResult, StashKey, Subdiagnostic};
-use rustc_lexer::unescape::unescape_char;
 use rustc_macros::Subdiagnostic;
 use rustc_session::errors::{ExprParenthesesNeeded, report_lit_error};
 use rustc_session::lint::BuiltinLintDiag;
@@ -2588,7 +2588,8 @@ impl<'a> Parser<'a> {
     }
 
     /// Parses the condition of a `if` or `while` expression.
-    fn parse_expr_cond(&mut self) -> PResult<'a, P<Expr>> {
+    // Public because it is used in rustfmt forks such as https://github.com/tucant/rustfmt/blob/30c83df9e1db10007bdd16dafce8a86b404329b2/src/parse/macros/html.rs#L57 for custom if expressions.
+    pub fn parse_expr_cond(&mut self) -> PResult<'a, P<Expr>> {
         let attrs = self.parse_outer_attributes()?;
         let (mut cond, _) =
             self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL | Restrictions::ALLOW_LET, attrs)?;