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Add a b'x' byte literal of type u8.
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SimonSapin committed Jun 17, 2014
1 parent 2fd618e commit bccdba0
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Showing 16 changed files with 169 additions and 5 deletions.
1 change: 1 addition & 0 deletions src/librustc/middle/const_eval.rs
Expand Up @@ -506,6 +506,7 @@ pub fn lit_to_const(lit: &Lit) -> const_val {
LitBinary(ref data) => {
const_binary(Rc::new(data.iter().map(|x| *x).collect()))
}
LitByte(n) => const_uint(n as u64),
LitChar(n) => const_uint(n as u64),
LitInt(n, _) => const_int(n),
LitUint(n, _) => const_uint(n),
Expand Down
1 change: 1 addition & 0 deletions src/librustc/middle/lint.rs
Expand Up @@ -805,6 +805,7 @@ fn check_type_limits(cx: &Context, e: &ast::Expr) {
} else { t };
let (min, max) = uint_ty_range(uint_type);
let lit_val: u64 = match lit.node {
ast::LitByte(_v) => return, // _v is u8, within range by definition
ast::LitInt(v, _) => v as u64,
ast::LitUint(v, _) => v,
ast::LitIntUnsuffixed(v) => v as u64,
Expand Down
1 change: 1 addition & 0 deletions src/librustc/middle/trans/consts.rs
Expand Up @@ -43,6 +43,7 @@ pub fn const_lit(cx: &CrateContext, e: &ast::Expr, lit: ast::Lit)
-> ValueRef {
let _icx = push_ctxt("trans_lit");
match lit.node {
ast::LitByte(b) => C_integral(Type::uint_from_ty(cx, ast::TyU8), b as u64, false),
ast::LitChar(i) => C_integral(Type::char(cx), i as u64, false),
ast::LitInt(i, t) => C_integral(Type::int_from_ty(cx, t), i as u64, true),
ast::LitUint(u, t) => C_integral(Type::uint_from_ty(cx, t), u, false),
Expand Down
1 change: 1 addition & 0 deletions src/librustc/middle/typeck/check/mod.rs
Expand Up @@ -1715,6 +1715,7 @@ pub fn check_lit(fcx: &FnCtxt, lit: &ast::Lit) -> ty::t {
ast::LitBinary(..) => {
ty::mk_slice(tcx, ty::ReStatic, ty::mt{ ty: ty::mk_u8(), mutbl: ast::MutImmutable })
}
ast::LitByte(_) => ty::mk_u8(),
ast::LitChar(_) => ty::mk_char(),
ast::LitInt(_, t) => ty::mk_mach_int(t),
ast::LitUint(_, t) => ty::mk_mach_uint(t),
Expand Down
8 changes: 8 additions & 0 deletions src/librustdoc/clean/mod.rs
Expand Up @@ -1924,6 +1924,14 @@ fn lit_to_str(lit: &ast::Lit) -> String {
match lit.node {
ast::LitStr(ref st, _) => st.get().to_string(),
ast::LitBinary(ref data) => format!("{:?}", data.as_slice()),
ast::LitByte(b) => {
let mut res = String::from_str("b'");
(b as char).escape_default(|c| {
res.push_char(c);
});
res.push_char('\'');
res
},
ast::LitChar(c) => format!("'{}'", c),
ast::LitInt(i, _t) => i.to_str(),
ast::LitUint(u, _t) => u.to_str(),
Expand Down
2 changes: 1 addition & 1 deletion src/librustdoc/html/highlight.rs
Expand Up @@ -140,7 +140,7 @@ fn doit(sess: &parse::ParseSess, mut lexer: lexer::StringReader,
}

// text literals
t::LIT_CHAR(..) | t::LIT_STR(..) | t::LIT_STR_RAW(..) => "string",
t::LIT_BYTE(..) | t::LIT_CHAR(..) | t::LIT_STR(..) | t::LIT_STR_RAW(..) => "string",

// number literals
t::LIT_INT(..) | t::LIT_UINT(..) | t::LIT_INT_UNSUFFIXED(..) |
Expand Down
1 change: 1 addition & 0 deletions src/libsyntax/ast.rs
Expand Up @@ -616,6 +616,7 @@ pub type Lit = Spanned<Lit_>;
pub enum Lit_ {
LitStr(InternedString, StrStyle),
LitBinary(Rc<Vec<u8> >),
LitByte(u8),
LitChar(char),
LitInt(i64, IntTy),
LitUint(u64, UintTy),
Expand Down
1 change: 1 addition & 0 deletions src/libsyntax/ext/concat.rs
Expand Up @@ -47,6 +47,7 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
ast::LitBool(b) => {
accumulator.push_str(format!("{}", b).as_slice());
}
ast::LitByte(..) |
ast::LitBinary(..) => {
cx.span_err(e.span, "cannot concatenate a binary literal");
}
Expand Down
6 changes: 6 additions & 0 deletions src/libsyntax/ext/quote.rs
Expand Up @@ -436,6 +436,12 @@ fn mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> Gc<ast::Expr> {
vec!(mk_binop(cx, sp, binop)));
}

LIT_BYTE(i) => {
let e_byte = cx.expr_lit(sp, ast::LitByte(i));

return cx.expr_call(sp, mk_token_path(cx, sp, "LIT_BYTE"), vec!(e_byte));
}

LIT_CHAR(i) => {
let e_char = cx.expr_lit(sp, ast::LitChar(i));

Expand Down
68 changes: 65 additions & 3 deletions src/libsyntax/parse/lexer/mod.rs
Expand Up @@ -650,10 +650,13 @@ impl<'a> StringReader<'a> {
/// token, and updates the interner
fn next_token_inner(&mut self) -> token::Token {
let c = self.curr;
if ident_start(c) && !self.nextch_is('"') && !self.nextch_is('#') {
if ident_start(c) && match (c.unwrap(), self.nextch()) {
// Note: r as in r" or r#" is part of a raw string literal,
// not an identifier, and is handled further down.

// b as in b' is part of a byte literal.
// They are not identifiers, and are handled further down.
('r', Some('"')) | ('r', Some('#')) | ('b', Some('\'')) => false,
_ => true
} {
let start = self.last_pos;
while ident_continue(self.curr) {
self.bump();
Expand Down Expand Up @@ -854,6 +857,65 @@ impl<'a> StringReader<'a> {
self.bump(); // advance curr past token
return token::LIT_CHAR(c2);
}
'b' => {
self.bump();
assert!(self.curr_is('\''), "Should have been a token::IDENT");
self.bump();
let start = self.last_pos;

// the eof will be picked up by the final `'` check below
let mut c2 = self.curr.unwrap_or('\x00');
self.bump();

match c2 {
'\\' => {
// '\X' for some X must be a character constant:
let escaped = self.curr;
let escaped_pos = self.last_pos;
self.bump();
match escaped {
None => {}
Some(e) => {
c2 = match e {
'n' => '\n',
'r' => '\r',
't' => '\t',
'\\' => '\\',
'\'' => '\'',
'"' => '"',
'0' => '\x00',
'x' => self.scan_numeric_escape(2u, '\''),
c2 => {
self.err_span_char(escaped_pos, self.last_pos,
"unknown byte escape", c2);
c2
}
}
}
}
}
'\t' | '\n' | '\r' | '\'' => {
self.err_span_char( start, self.last_pos,
"byte constant must be escaped", c2);
}
_ if c2 > '\x7F' => {
self.err_span_char( start, self.last_pos,
"byte constant must be ASCII. \
Use a \\xHH escape for a non-ASCII byte", c2);
}
_ => {}
}
if !self.curr_is('\'') {
self.fatal_span_verbose(
// Byte offsetting here is okay because the
// character before position `start` are an
// ascii single quote and ascii 'b'.
start - BytePos(2), self.last_pos,
"unterminated byte constant".to_string());
}
self.bump(); // advance curr past token
return token::LIT_BYTE(c2 as u8);
}
'"' => {
let mut accum_str = String::new();
let start_bpos = self.last_pos;
Expand Down
3 changes: 2 additions & 1 deletion src/libsyntax/parse/parser.rs
Expand Up @@ -33,7 +33,7 @@ use ast::{ForeignItem, ForeignItemStatic, ForeignItemFn, ForeignMod};
use ast::{Ident, NormalFn, Inherited, Item, Item_, ItemStatic};
use ast::{ItemEnum, ItemFn, ItemForeignMod, ItemImpl};
use ast::{ItemMac, ItemMod, ItemStruct, ItemTrait, ItemTy, Lit, Lit_};
use ast::{LitBool, LitFloat, LitFloatUnsuffixed, LitInt, LitChar};
use ast::{LitBool, LitFloat, LitFloatUnsuffixed, LitInt, LitChar, LitByte};
use ast::{LitIntUnsuffixed, LitNil, LitStr, LitUint, Local, LocalLet};
use ast::{MutImmutable, MutMutable, Mac_, MacInvocTT, Matcher, MatchNonterminal};
use ast::{MatchSeq, MatchTok, Method, MutTy, BiMul, Mutability};
Expand Down Expand Up @@ -1512,6 +1512,7 @@ impl<'a> Parser<'a> {
// matches token_lit = LIT_INT | ...
pub fn lit_from_token(&mut self, tok: &token::Token) -> Lit_ {
match *tok {
token::LIT_BYTE(i) => LitByte(i),
token::LIT_CHAR(i) => LitChar(i),
token::LIT_INT(i, it) => LitInt(i, it),
token::LIT_UINT(u, ut) => LitUint(u, ut),
Expand Down
11 changes: 11 additions & 0 deletions src/libsyntax/parse/token.rs
Expand Up @@ -78,6 +78,7 @@ pub enum Token {
DOLLAR,

/* Literals */
LIT_BYTE(u8),
LIT_CHAR(char),
LIT_INT(i64, ast::IntTy),
LIT_UINT(u64, ast::UintTy),
Expand Down Expand Up @@ -193,6 +194,14 @@ pub fn to_str(t: &Token) -> String {
DOLLAR => "$".to_string(),

/* Literals */
LIT_BYTE(b) => {
let mut res = String::from_str("b'");
(b as char).escape_default(|c| {
res.push_char(c);
});
res.push_char('\'');
res
}
LIT_CHAR(c) => {
let mut res = String::from_str("'");
c.escape_default(|c| {
Expand Down Expand Up @@ -273,6 +282,7 @@ pub fn can_begin_expr(t: &Token) -> bool {
IDENT(_, _) => true,
UNDERSCORE => true,
TILDE => true,
LIT_BYTE(_) => true,
LIT_CHAR(_) => true,
LIT_INT(_, _) => true,
LIT_UINT(_, _) => true,
Expand Down Expand Up @@ -311,6 +321,7 @@ pub fn close_delimiter_for(t: &Token) -> Option<Token> {

pub fn is_lit(t: &Token) -> bool {
match *t {
LIT_BYTE(_) => true,
LIT_CHAR(_) => true,
LIT_INT(_, _) => true,
LIT_UINT(_, _) => true,
Expand Down
6 changes: 6 additions & 0 deletions src/libsyntax/print/pprust.rs
Expand Up @@ -2305,6 +2305,12 @@ impl<'a> State<'a> {
}
match lit.node {
ast::LitStr(ref st, style) => self.print_string(st.get(), style),
ast::LitByte(byte) => {
let mut res = String::from_str("b'");
(byte as char).escape_default(|c| res.push_char(c));
res.push_char('\'');
word(&mut self.s, res.as_slice())
}
ast::LitChar(ch) => {
let mut res = String::from_str("'");
ch.escape_default(|c| res.push_char(c));
Expand Down
25 changes: 25 additions & 0 deletions src/test/compile-fail/byte-literals.rs
@@ -0,0 +1,25 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.


// ignore-tidy-tab

static FOO: u8 = b'\f'; //~ ERROR unknown byte escape

pub fn main() {
b'\f'; //~ ERROR unknown byte escape
b'\x0Z'; //~ ERROR illegal character in numeric character escape: Z
b' '; //~ ERROR byte constant must be escaped
b'''; //~ ERROR byte constant must be escaped
b'é'; //~ ERROR byte constant must be ASCII
b'a //~ ERROR unterminated byte constant
}


1 change: 1 addition & 0 deletions src/test/compile-fail/concat.rs
Expand Up @@ -9,6 +9,7 @@
// except according to those terms.

fn main() {
concat!(b'f'); //~ ERROR: cannot concatenate a binary literal
concat!(foo); //~ ERROR: expected a literal
concat!(foo()); //~ ERROR: expected a literal
}
38 changes: 38 additions & 0 deletions src/test/run-pass/byte-literals.rs
@@ -0,0 +1,38 @@
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.


static FOO: u8 = b'\xF0';

pub fn main() {
assert_eq!(b'a', 97u8);
assert_eq!(b'\n', 10u8);
assert_eq!(b'\r', 13u8);
assert_eq!(b'\t', 9u8);
assert_eq!(b'\\', 92u8);
assert_eq!(b'\'', 39u8);
assert_eq!(b'\"', 34u8);
assert_eq!(b'\0', 0u8);
assert_eq!(b'\xF0', 240u8);
assert_eq!(FOO, 240u8);

// FIXME: Do we want this to be valid?
assert_eq!([42, ..b'\t'].as_slice(), &[42, 42, 42, 42, 42, 42, 42, 42, 42]);

match 42 {
b'*' => {},
_ => fail!()
}

match 100 {
b'a' .. b'z' => {},
_ => fail!()
}
}

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