diff options
Diffstat (limited to 'compiler/rustc_expand/src/mbe/transcribe.rs')
| -rw-r--r-- | compiler/rustc_expand/src/mbe/transcribe.rs | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/compiler/rustc_expand/src/mbe/transcribe.rs b/compiler/rustc_expand/src/mbe/transcribe.rs index 595c8c3279f..7fe9fa7937d 100644 --- a/compiler/rustc_expand/src/mbe/transcribe.rs +++ b/compiler/rustc_expand/src/mbe/transcribe.rs @@ -1,10 +1,13 @@ use std::mem; use std::sync::Arc; -use rustc_ast::ExprKind; use rustc_ast::mut_visit::{self, MutVisitor}; -use rustc_ast::token::{self, Delimiter, IdentIsRaw, Lit, LitKind, Nonterminal, Token, TokenKind}; +use rustc_ast::token::{ + self, Delimiter, IdentIsRaw, InvisibleOrigin, Lit, LitKind, MetaVarKind, Nonterminal, Token, + TokenKind, +}; use rustc_ast::tokenstream::{DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree}; +use rustc_ast::{ExprKind, TyKind}; use rustc_data_structures::fx::FxHashMap; use rustc_errors::{Diag, DiagCtxtHandle, PResult, pluralize}; use rustc_parse::lexer::nfc_normalize; @@ -255,7 +258,7 @@ pub(super) fn transcribe<'a>( } // Replace the meta-var with the matched token tree from the invocation. - mbe::TokenTree::MetaVar(mut sp, mut original_ident) => { + &mbe::TokenTree::MetaVar(mut sp, mut original_ident) => { // Find the matched nonterminal from the macro invocation, and use it to replace // the meta-var. // @@ -274,6 +277,33 @@ pub(super) fn transcribe<'a>( // some of the unnecessary whitespace. let ident = MacroRulesNormalizedIdent::new(original_ident); if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) { + // We wrap the tokens in invisible delimiters, unless they are already wrapped + // in invisible delimiters with the same `MetaVarKind`. Because some proc + // macros can't multiple layers of invisible delimiters of the same + // `MetaVarKind`. This loses some span info, though it hopefully won't matter. + let mut mk_delimited = |mv_kind, mut stream: TokenStream| { + if stream.len() == 1 { + let tree = stream.iter().next().unwrap(); + if let TokenTree::Delimited(_, _, delim, inner) = tree + && let Delimiter::Invisible(InvisibleOrigin::MetaVar(mvk)) = delim + && mv_kind == *mvk + { + stream = inner.clone(); + } + } + + // Emit as a token stream within `Delimiter::Invisible` to maintain + // parsing priorities. + marker.visit_span(&mut sp); + // Both the open delim and close delim get the same span, which covers the + // `$foo` in the decl macro RHS. + TokenTree::Delimited( + DelimSpan::from_single(sp), + DelimSpacing::new(Spacing::Alone, Spacing::Alone), + Delimiter::Invisible(InvisibleOrigin::MetaVar(mv_kind)), + stream, + ) + }; let tt = match cur_matched { MatchedSingle(ParseNtResult::Tt(tt)) => { // `tt`s are emitted into the output stream directly as "raw tokens", @@ -292,6 +322,13 @@ pub(super) fn transcribe<'a>( let kind = token::NtLifetime(*ident, *is_raw); TokenTree::token_alone(kind, sp) } + MatchedSingle(ParseNtResult::Ty(ty)) => { + let is_path = matches!(&ty.kind, TyKind::Path(None, _path)); + mk_delimited(MetaVarKind::Ty { is_path }, TokenStream::from_ast(ty)) + } + MatchedSingle(ParseNtResult::Vis(vis)) => { + mk_delimited(MetaVarKind::Vis, TokenStream::from_ast(vis)) + } MatchedSingle(ParseNtResult::Nt(nt)) => { // Other variables are emitted into the output stream as groups with // `Delimiter::Invisible` to maintain parsing priorities. @@ -339,7 +376,7 @@ pub(super) fn transcribe<'a>( // We will produce all of the results of the inside of the `Delimited` and then we will // jump back out of the Delimited, pop the result_stack and add the new results back to // the previous results (from outside the Delimited). - mbe::TokenTree::Delimited(mut span, spacing, delimited) => { + &mbe::TokenTree::Delimited(mut span, ref spacing, ref delimited) => { mut_visit::visit_delim_span(&mut marker, &mut span); stack.push(Frame::new_delimited(delimited, span, *spacing)); result_stack.push(mem::take(&mut result)); |