mathieu/os-rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Simplify lower_mac_args.

Browse source 
The `token` is always an interpolated non-terminal expression, and
always a literal in valid code. This commit simplifies the processing
accordingly, by directly extracting and using the literal.
This commit is contained in:
Nicholas Nethercote 2022-04-28 14:12:40 +10:00
parent 481a4461ae
commit cde25f8dbe
1 changed files with 14 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

42
compiler/rustc_ast_lowering/src/lib.rs
View file

@ -38,8 +38,8 @@
#![recursion_limit = "256"]
#![allow(rustc::potential_query_instability)]
use rustc_ast::token::{Delimiter, Token};
use rustc_ast::tokenstream::{CanSynthesizeMissingTokens, TokenStream, TokenTree};
use rustc_ast::token::{self, Token, TokenKind};
use rustc_ast::tokenstream::{CanSynthesizeMissingTokens, TokenStream};
use rustc_ast::visit;
use rustc_ast::{self as ast, *};
use rustc_ast_pretty::pprust;
@ -878,33 +878,19 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
// spans to handle nonterminals in `#[doc]` (e.g. `#[doc = $e]`).
MacArgs::Eq(eq_span, ref token) => {
// In valid code the value is always representable as a single literal token.
fn unwrap_single_token(sess: &Session, tokens: TokenStream, span: Span) -> Token {
if tokens.len() != 1 {
sess.diagnostic()
.delay_span_bug(span, "multiple tokens in key-value attribute's value");
// Otherwise, a dummy token suffices because the error is handled elsewhere.
let token = if let token::Interpolated(nt) = &token.kind
&& let token::NtExpr(expr) = &**nt
{
if let ExprKind::Lit(Lit { token, span, .. }) = expr.kind {
Token::new(TokenKind::Literal(token), span)
} else {
Token::dummy()
}
match tokens.into_trees().next() {
Some(TokenTree::Token(token)) => token,
Some(TokenTree::Delimited(_, delim, tokens)) => {
if delim != Delimiter::Invisible {
sess.diagnostic().delay_span_bug(
span,
"unexpected delimiter in key-value attribute's value",
);
}
unwrap_single_token(sess, tokens, span)
}
None => Token::dummy(),
}
}
let tokens = FlattenNonterminals {
parse_sess: &self.sess.parse_sess,
synthesize_tokens: CanSynthesizeMissingTokens::Yes,
nt_to_tokenstream: self.nt_to_tokenstream,
}
.process_token(token.clone());
MacArgs::Eq(eq_span, unwrap_single_token(self.sess, tokens, token.span))
} else {
unreachable!()
};
MacArgs::Eq(eq_span, token)
}
}
}