bjoernager/rust
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Move literal parsing code into a separate file

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Remove some dead code
This commit is contained in:
Vadim Petrochenkov 2019-05-11 02:31:34 +03:00
parent 8739668438
commit 3f064cae3d
13 changed files with 521 additions and 537 deletions
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352
src/libsyntax/parse/mod.rs
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@ -1,11 +1,10 @@
//! The main parser interface.
use crate::ast::{self, CrateConfig, LitKind, NodeId};
use crate::ast::{self, CrateConfig, NodeId};
use crate::early_buffered_lints::{BufferedEarlyLint, BufferedEarlyLintId};
use crate::source_map::{SourceMap, FilePathMapping};
use crate::feature_gate::UnstableFeatures;
use crate::parse::parser::Parser;
use crate::symbol::{keywords, Symbol};
use crate::syntax::parse::parser::emit_unclosed_delims;
use crate::tokenstream::{TokenStream, TokenTree};
use crate::diagnostics::plugin::ErrorMap;
@ -14,7 +13,6 @@ use crate::print::pprust::token_to_string;
use errors::{Applicability, FatalError, Level, Handler, ColorConfig, Diagnostic, DiagnosticBuilder};
use rustc_data_structures::sync::{Lrc, Lock};
use syntax_pos::{Span, SourceFile, FileName, MultiSpan};
use log::debug;
use rustc_data_structures::fx::{FxHashSet, FxHashMap};
use std::borrow::Cow;
@ -25,18 +23,15 @@ pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
#[macro_use]
pub mod parser;
pub mod attr;
pub mod lexer;
pub mod token;
pub mod attr;
pub mod diagnostics;
pub mod classify;
pub(crate) mod unescape;
use unescape::{unescape_str, unescape_char, unescape_byte_str, unescape_byte};
pub(crate) mod unescape_error_reporting;
crate mod classify;
crate mod diagnostics;
crate mod literal;
crate mod unescape;
crate mod unescape_error_reporting;
/// Info about a parsing session.
pub struct ParseSess {
@ -334,339 +329,6 @@ pub fn stream_to_parser(sess: &ParseSess, stream: TokenStream) -> Parser<'_> {
Parser::new(sess, stream, None, true, false)
}
/// Parses a string representing a raw string literal into its final form. The
/// only operation this does is convert embedded CRLF into a single LF.
fn raw_str_lit(lit: &str) -> String {
debug!("raw_str_lit: given {}", lit.escape_default());
let mut res = String::with_capacity(lit.len());
let mut chars = lit.chars().peekable();
while let Some(c) = chars.next() {
if c == '\r' {
if *chars.peek().unwrap() != '\n' {
panic!("lexer accepted bare CR");
}
chars.next();
res.push('\n');
} else {
res.push(c);
}
}
res.shrink_to_fit();
res
}
// check if `s` looks like i32 or u1234 etc.
fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
s.starts_with(first_chars) && s[1..].chars().all(|c| c.is_ascii_digit())
}
macro_rules! err {
($opt_diag:expr, |$span:ident, $diag:ident| $($body:tt)*) => {
match $opt_diag {
Some(($span, $diag)) => { $($body)* }
None => return None,
}
}
}
crate fn expect_no_suffix(sp: Span, diag: &Handler, kind: &str, suffix: Option<ast::Name>) {
match suffix {
None => {/* everything ok */}
Some(suf) => {
let text = suf.as_str();
if text.is_empty() {
diag.span_bug(sp, "found empty literal suffix in Some")
}
let mut err = if kind == "a tuple index" &&
["i32", "u32", "isize", "usize"].contains(&text.to_string().as_str())
{
// #59553: warn instead of reject out of hand to allow the fix to percolate
// through the ecosystem when people fix their macros
let mut err = diag.struct_span_warn(
sp,
&format!("suffixes on {} are invalid", kind),
);
err.note(&format!(
"`{}` is *temporarily* accepted on tuple index fields as it was \
incorrectly accepted on stable for a few releases",
text,
));
err.help(
"on proc macros, you'll want to use `syn::Index::from` or \
`proc_macro::Literal::*_unsuffixed` for code that will desugar \
to tuple field access",
);
err.note(
"for more context, see https://github.com/rust-lang/rust/issues/60210",
);
err
} else {
diag.struct_span_err(sp, &format!("suffixes on {} are invalid", kind))
};
err.span_label(sp, format!("invalid suffix `{}`", text));
err.emit();
}
}
}
impl LitKind {
/// Converts literal token with a suffix into a semantic literal.
/// Works speculatively and may return `None` is diagnostic handler is not passed.
/// If diagnostic handler is passed, always returns `Some`,
/// possibly after reporting non-fatal errors and recovery.
crate fn from_lit_token(
lit: token::Lit,
suf: Option<Symbol>,
diag: Option<(Span, &Handler)>
) -> Option<LitKind> {
if suf.is_some() && !lit.may_have_suffix() {
err!(diag, |span, diag| {
expect_no_suffix(span, diag, &format!("a {}", lit.literal_name()), suf)
});
}
Some(match lit {
token::Bool(i) => {
assert!(i == keywords::True.name() || i == keywords::False.name());
LitKind::Bool(i == keywords::True.name())
}
token::Byte(i) => {
match unescape_byte(&i.as_str()) {
Ok(c) => LitKind::Byte(c),
Err(_) => LitKind::Err(i),
}
},
token::Char(i) => {
match unescape_char(&i.as_str()) {
Ok(c) => LitKind::Char(c),
Err(_) => LitKind::Err(i),
}
},
token::Err(i) => LitKind::Err(i),
// There are some valid suffixes for integer and float literals,
// so all the handling is done internally.
token::Integer(s) => return integer_lit(&s.as_str(), suf, diag),
token::Float(s) => return float_lit(&s.as_str(), suf, diag),
token::Str_(mut sym) => {
// If there are no characters requiring special treatment we can
// reuse the symbol from the Token. Otherwise, we must generate a
// new symbol because the string in the LitKind is different to the
// string in the Token.
let mut has_error = false;
let s = &sym.as_str();
if s.as_bytes().iter().any(|&c| c == b'\\' || c == b'\r') {
let mut buf = String::with_capacity(s.len());
unescape_str(s, &mut |_, unescaped_char| {
match unescaped_char {
Ok(c) => buf.push(c),
Err(_) => has_error = true,
}
});
if has_error {
return Some(LitKind::Err(sym));
}
sym = Symbol::intern(&buf)
}
LitKind::Str(sym, ast::StrStyle::Cooked)
}
token::StrRaw(mut sym, n) => {
// Ditto.
let s = &sym.as_str();
if s.contains('\r') {
sym = Symbol::intern(&raw_str_lit(s));
}
LitKind::Str(sym, ast::StrStyle::Raw(n))
}
token::ByteStr(i) => {
let s = &i.as_str();
let mut buf = Vec::with_capacity(s.len());
let mut has_error = false;
unescape_byte_str(s, &mut |_, unescaped_byte| {
match unescaped_byte {
Ok(c) => buf.push(c),
Err(_) => has_error = true,
}
});
if has_error {
return Some(LitKind::Err(i));
}
buf.shrink_to_fit();
LitKind::ByteStr(Lrc::new(buf))
}
token::ByteStrRaw(i, _) => {
LitKind::ByteStr(Lrc::new(i.to_string().into_bytes()))
}
})
}
}
fn filtered_float_lit(data: Symbol, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
-> Option<LitKind> {
debug!("filtered_float_lit: {}, {:?}", data, suffix);
let suffix = match suffix {
Some(suffix) => suffix,
None => return Some(LitKind::FloatUnsuffixed(data)),
};
Some(match &*suffix.as_str() {
"f32" => LitKind::Float(data, ast::FloatTy::F32),
"f64" => LitKind::Float(data, ast::FloatTy::F64),
suf => {
err!(diag, |span, diag| {
if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
// if it looks like a width, lets try to be helpful.
let msg = format!("invalid width `{}` for float literal", &suf[1..]);
diag.struct_span_err(span, &msg).help("valid widths are 32 and 64").emit()
} else {
let msg = format!("invalid suffix `{}` for float literal", suf);
diag.struct_span_err(span, &msg)
.span_label(span, format!("invalid suffix `{}`", suf))
.help("valid suffixes are `f32` and `f64`")
.emit();
}
});
LitKind::FloatUnsuffixed(data)
}
})
}
fn float_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
-> Option<LitKind> {
debug!("float_lit: {:?}, {:?}", s, suffix);
// FIXME #2252: bounds checking float literals is deferred until trans
// Strip underscores without allocating a new String unless necessary.
let s2;
let s = if s.chars().any(|c| c == '_') {
s2 = s.chars().filter(|&c| c != '_').collect::<String>();
&s2
} else {
s
};
filtered_float_lit(Symbol::intern(s), suffix, diag)
}
fn integer_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
-> Option<LitKind> {
// s can only be ascii, byte indexing is fine
// Strip underscores without allocating a new String unless necessary.
let s2;
let mut s = if s.chars().any(|c| c == '_') {
s2 = s.chars().filter(|&c| c != '_').collect::<String>();
&s2
} else {
s
};
debug!("integer_lit: {}, {:?}", s, suffix);
let mut base = 10;
let orig = s;
let mut ty = ast::LitIntType::Unsuffixed;
if s.starts_with('0') && s.len() > 1 {
match s.as_bytes()[1] {
b'x' => base = 16,
b'o' => base = 8,
b'b' => base = 2,
_ => { }
}
}
// 1f64 and 2f32 etc. are valid float literals.
if let Some(suf) = suffix {
if looks_like_width_suffix(&['f'], &suf.as_str()) {
let err = match base {
16 => Some("hexadecimal float literal is not supported"),
8 => Some("octal float literal is not supported"),
2 => Some("binary float literal is not supported"),
_ => None,
};
if let Some(err) = err {
err!(diag, |span, diag| {
diag.struct_span_err(span, err)
.span_label(span, "not supported")
.emit();
});
}
return filtered_float_lit(Symbol::intern(s), Some(suf), diag)
}
}
if base != 10 {
s = &s[2..];
}
if let Some(suf) = suffix {
if suf.as_str().is_empty() {
err!(diag, |span, diag| diag.span_bug(span, "found empty literal suffix in Some"));
}
ty = match &*suf.as_str() {
"isize" => ast::LitIntType::Signed(ast::IntTy::Isize),
"i8" => ast::LitIntType::Signed(ast::IntTy::I8),
"i16" => ast::LitIntType::Signed(ast::IntTy::I16),
"i32" => ast::LitIntType::Signed(ast::IntTy::I32),
"i64" => ast::LitIntType::Signed(ast::IntTy::I64),
"i128" => ast::LitIntType::Signed(ast::IntTy::I128),
"usize" => ast::LitIntType::Unsigned(ast::UintTy::Usize),
"u8" => ast::LitIntType::Unsigned(ast::UintTy::U8),
"u16" => ast::LitIntType::Unsigned(ast::UintTy::U16),
"u32" => ast::LitIntType::Unsigned(ast::UintTy::U32),
"u64" => ast::LitIntType::Unsigned(ast::UintTy::U64),
"u128" => ast::LitIntType::Unsigned(ast::UintTy::U128),
suf => {
// i<digits> and u<digits> look like widths, so lets
// give an error message along those lines
err!(diag, |span, diag| {
if looks_like_width_suffix(&['i', 'u'], suf) {
let msg = format!("invalid width `{}` for integer literal", &suf[1..]);
diag.struct_span_err(span, &msg)
.help("valid widths are 8, 16, 32, 64 and 128")
.emit();
} else {
let msg = format!("invalid suffix `{}` for numeric literal", suf);
diag.struct_span_err(span, &msg)
.span_label(span, format!("invalid suffix `{}`", suf))
.help("the suffix must be one of the integral types \
(`u32`, `isize`, etc)")
.emit();
}
});
ty
}
}
}
debug!("integer_lit: the type is {:?}, base {:?}, the new string is {:?}, the original \
string was {:?}, the original suffix was {:?}", ty, base, s, orig, suffix);
Some(match u128::from_str_radix(s, base) {
Ok(r) => LitKind::Int(r, ty),
Err(_) => {
// small bases are lexed as if they were base 10, e.g, the string
// might be `0b10201`. This will cause the conversion above to fail,
// but these cases have errors in the lexer: we don't want to emit
// two errors, and we especially don't want to emit this error since
// it isn't necessarily true.
let already_errored = base < 10 &&
s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
if !already_errored {
err!(diag, |span, diag| diag.span_err(span, "int literal is too large"));
}
LitKind::Int(0, ty)
}
})
}
/// A sequence separator.
pub struct SeqSep {
/// The seperator token.