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rustc_parse: More precise spans for tuple.0.0

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This commit is contained in:
Vadim Petrochenkov 2020-10-10 02:01:44 +03:00
parent b1af43bc63
commit dee704930d
4 changed files with 45 additions and 19 deletions
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40
compiler/rustc_parse/src/parser/expr.rs
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@ -16,6 +16,7 @@ use rustc_ast_pretty::pprust;
use rustc_errors::{Applicability, DiagnosticBuilder, PResult};
use rustc_span::source_map::{self, Span, Spanned};
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::{BytePos, Pos};
use std::mem;
use tracing::debug;
@ -839,9 +840,10 @@ impl<'a> Parser<'a> {
}
use FloatComponent::*;
let float_str = float.as_str();
let mut components = Vec::new();
let mut ident_like = String::new();
for c in float.as_str().chars() {
for c in float_str.chars() {
if c == '_' || c.is_ascii_alphanumeric() {
ident_like.push(c);
} else if matches!(c, '.' | '+' | '-') {
@ -857,8 +859,13 @@ impl<'a> Parser<'a> {
components.push(IdentLike(ident_like));
}
// FIXME: Make the span more precise.
// With proc macros the span can refer to anything, the source may be too short,
// or too long, or non-ASCII. It only makes sense to break our span into components
// if its underlying text is identical to our float literal.
let span = self.token.span;
let can_take_span_apart =
|| self.span_to_snippet(span).as_deref() == Ok(float_str).as_deref();
match &*components {
// 1e2
[IdentLike(i)] => {
@ -866,21 +873,40 @@ impl<'a> Parser<'a> {
}
// 1.
[IdentLike(i), Punct('.')] => {
let (ident_span, dot_span) = if can_take_span_apart() {
let (span, ident_len) = (span.data(), BytePos::from_usize(i.len()));
let ident_span = span.with_hi(span.lo + ident_len);
let dot_span = span.with_lo(span.lo + ident_len);
(ident_span, dot_span)
} else {
(span, span)
};
assert!(suffix.is_none());
let symbol = Symbol::intern(&i);
self.token = Token::new(token::Ident(symbol, false), span);
let next_token = Token::new(token::Dot, span);
self.token = Token::new(token::Ident(symbol, false), ident_span);
let next_token = Token::new(token::Dot, dot_span);
self.parse_tuple_field_access_expr(lo, base, symbol, None, Some(next_token))
}
// 1.2 | 1.2e3
[IdentLike(i1), Punct('.'), IdentLike(i2)] => {
let (ident1_span, dot_span, ident2_span) = if can_take_span_apart() {
let (span, ident1_len) = (span.data(), BytePos::from_usize(i1.len()));
let ident1_span = span.with_hi(span.lo + ident1_len);
let dot_span = span
.with_lo(span.lo + ident1_len)
.with_hi(span.lo + ident1_len + BytePos(1));
let ident2_span = self.token.span.with_lo(span.lo + ident1_len + BytePos(1));
(ident1_span, dot_span, ident2_span)
} else {
(span, span, span)
};
let symbol1 = Symbol::intern(&i1);
self.token = Token::new(token::Ident(symbol1, false), span);
let next_token1 = Token::new(token::Dot, span);
self.token = Token::new(token::Ident(symbol1, false), ident1_span);
let next_token1 = Token::new(token::Dot, dot_span);
let base1 =
self.parse_tuple_field_access_expr(lo, base, symbol1, None, Some(next_token1));
let symbol2 = Symbol::intern(&i2);
let next_token2 = Token::new(token::Ident(symbol2, false), span);
let next_token2 = Token::new(token::Ident(symbol2, false), ident2_span);
self.bump_with(next_token2); // `.`
self.parse_tuple_field_access_expr(lo, base1, symbol2, suffix, None)
}