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preserve delim spans during macro_rules! expansion if able

This commit is contained in:
Lukas Markeffsky 2023-01-15 17:49:34 +01:00
parent b9e8286c85
commit 31443c63b5
4 changed files with 30 additions and 23 deletions

View file

@ -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};
use rustc_ast::tokenstream::{DelimSpan, TokenStream, TokenTree};
use rustc_ast::{NodeId, DUMMY_NODE_ID};
use rustc_ast_pretty::pprust;
use rustc_attr::{self as attr, TransparencyError};
@ -212,7 +212,6 @@ fn expand_macro<'cx>(
};
let arm_span = rhses[i].span();
let rhs_spans = rhs.tts.iter().map(|t| t.span()).collect::<Vec<_>>();
// rhs has holes ( `$id` and `$(...)` that need filled)
let mut tts = match transcribe(cx, &named_matches, &rhs, rhs_span, transparency) {
Ok(tts) => tts,
@ -224,12 +223,25 @@ 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 rhs_spans.len() == tts.len() {
if tts.len() == rhs.tts.len() {
tts = tts.map_enumerated(|i, tt| {
let mut tt = tt.clone();
let mut sp = rhs_spans[i];
sp = sp.with_ctxt(tt.span().ctxt());
tt.set_span(sp);
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);
}
_ => {
let sp = rhs_tt.span().with_ctxt(ctxt);
tt.set_span(sp);
}
}
tt
});
}