bjoernager/rust
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Support float-like tuple indices in offset_of!()

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The tokenizer gives us whole float literal tokens, we have to split them up
in order to be able to create field access from them.
This commit is contained in:
est31 2023-06-02 18:53:04 +02:00
parent d74ec96e8d
commit 1b90f5efaf
4 changed files with 344 additions and 21 deletions
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47
compiler/rustc_parse/src/parser/expr.rs
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@ -1852,10 +1852,53 @@ impl<'a> Parser<'a> {
let (fields, _trailing, _recovered) = self.parse_seq_to_before_end(
&TokenKind::CloseDelim(Delimiter::Parenthesis),
seq_sep,
Parser::parse_field_name,
|this| {
let token::Literal(token::Lit { kind: token::Float, symbol, suffix }) = this.token.kind
else {
return Ok(thin_vec![this.parse_field_name()?]);
};
let res = match this.break_up_float(symbol) {
// 1e2
DestructuredFloat::Single(sym, sp) => {
this.bump();
thin_vec![Ident::new(sym, sp)]
}
// 1.
DestructuredFloat::TrailingDot(sym, sym_span, dot_span) => {
assert!(suffix.is_none());
// Analogous to Self::break_and_eat
this.token_cursor.break_last_token = true;
// This might work, in cases like `1. 2.3`, and might not,
// in cases like `offset_of!(Ty, 1.)`.
this.token = Token::new(token::Ident(sym, false), sym_span);
this.bump_with((Token::new(token::Dot, dot_span), this.token_spacing));
thin_vec![Ident::new(sym, sym_span)]
}
// 1.2 | 1.2e3
DestructuredFloat::MiddleDot(
symbol1,
ident1_span,
_dot_span,
symbol2,
ident2_span,
) => {
this.bump();
thin_vec![
Ident::new(symbol1, ident1_span),
Ident::new(symbol2, ident2_span)
]
}
DestructuredFloat::Error => {
this.bump();
thin_vec![Ident::new(symbol, this.prev_token.span)]
}
};
Ok(res)
},
)?;
let fields = fields.into_iter().flatten().collect::<Vec<_>>();
let span = lo.to(self.token.span);
Ok(self.mk_expr(span, ExprKind::OffsetOf(container, fields.to_vec().into())))
Ok(self.mk_expr(span, ExprKind::OffsetOf(container, fields.into())))
}
/// Returns a string literal if the next token is a string literal.