зеркало из https://github.com/mozilla/gecko-dev.git
106 строки
4.3 KiB
Rust
106 строки
4.3 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#[macro_use] extern crate procedural_masquerade;
|
|
extern crate phf_codegen;
|
|
extern crate proc_macro;
|
|
#[macro_use] extern crate quote;
|
|
extern crate syn;
|
|
|
|
use std::ascii::AsciiExt;
|
|
|
|
define_proc_macros! {
|
|
/// Input: the arms of a `match` expression.
|
|
///
|
|
/// Output: a `MAX_LENGTH` constant with the length of the longest string pattern.
|
|
///
|
|
/// Panic if the arms contain non-string patterns,
|
|
/// or string patterns that contains ASCII uppercase letters.
|
|
#[allow(non_snake_case)]
|
|
pub fn cssparser_internal__assert_ascii_lowercase__max_len(input: &str) -> String {
|
|
let expr = syn::parse_expr(&format!("match x {{ {} }}", input)).unwrap();
|
|
let arms = match expr {
|
|
syn::Expr { node: syn::ExprKind::Match(_, ref arms), .. } => arms,
|
|
_ => panic!("expected a match expression, got {:?}", expr)
|
|
};
|
|
max_len(arms.iter().flat_map(|arm| &arm.pats).filter_map(|pattern| {
|
|
let expr = match *pattern {
|
|
syn::Pat::Lit(ref expr) => expr,
|
|
syn::Pat::Wild |
|
|
syn::Pat::Ident(_, _, None) => return None,
|
|
syn::Pat::Ident(_, _, Some(ref sub_pattern)) => {
|
|
match **sub_pattern {
|
|
syn::Pat::Lit(ref expr) => expr,
|
|
syn::Pat::Wild => return None,
|
|
_ => panic!("expected string or wildcard pattern, got {:?}", pattern)
|
|
}
|
|
}
|
|
_ => panic!("expected string or wildcard pattern, got {:?}", pattern)
|
|
};
|
|
match **expr {
|
|
syn::Expr { node: syn::ExprKind::Lit(syn::Lit::Str(ref string, _)), .. } => {
|
|
assert_eq!(*string, string.to_ascii_lowercase(),
|
|
"string patterns must be given in ASCII lowercase");
|
|
Some(string.len())
|
|
}
|
|
_ => panic!("expected string pattern, got {:?}", expr)
|
|
}
|
|
}))
|
|
}
|
|
|
|
/// Input: string literals with no separator
|
|
///
|
|
/// Output: a `MAX_LENGTH` constant with the length of the longest string.
|
|
#[allow(non_snake_case)]
|
|
pub fn cssparser_internal__max_len(input: &str) -> String {
|
|
max_len(syn::parse_token_trees(input).unwrap().iter().map(|tt| string_literal(tt).len()))
|
|
}
|
|
|
|
/// Input: parsed as token trees. The first TT is a type. (Can be wrapped in parens.)
|
|
/// following TTs are grouped in pairs, each pair being a key as a string literal
|
|
/// and the corresponding value as a const expression.
|
|
///
|
|
/// Output: a rust-phf map, with keys ASCII-lowercased:
|
|
/// ```
|
|
/// static MAP: &'static ::cssparser::phf::Map<&'static str, $ValueType> = …;
|
|
/// ```
|
|
#[allow(non_snake_case)]
|
|
pub fn cssparser_internal__phf_map(input: &str) -> String {
|
|
let token_trees = syn::parse_token_trees(input).unwrap();
|
|
let value_type = &token_trees[0];
|
|
let pairs: Vec<_> = token_trees[1..].chunks(2).map(|chunk| {
|
|
let key = string_literal(&chunk[0]);
|
|
let value = &chunk[1];
|
|
(key.to_ascii_lowercase(), quote!(#value).to_string())
|
|
}).collect();
|
|
|
|
let mut map = phf_codegen::Map::new();
|
|
map.phf_path("::cssparser::_internal__phf");
|
|
for &(ref key, ref value) in &pairs {
|
|
map.entry(&**key, &**value);
|
|
}
|
|
|
|
let mut tokens = quote! {
|
|
static MAP: ::cssparser::_internal__phf::Map<&'static str, #value_type> =
|
|
};
|
|
let mut initializer_bytes = Vec::new();
|
|
map.build(&mut initializer_bytes).unwrap();
|
|
tokens.append(::std::str::from_utf8(&initializer_bytes).unwrap());
|
|
tokens.append(";");
|
|
tokens.into_string()
|
|
}
|
|
}
|
|
|
|
fn max_len<I: Iterator<Item=usize>>(lengths: I) -> String {
|
|
let max_length = lengths.max().expect("expected at least one string");
|
|
quote!( const MAX_LENGTH: usize = #max_length; ).into_string()
|
|
}
|
|
|
|
fn string_literal(token: &syn::TokenTree) -> &str {
|
|
match *token {
|
|
syn::TokenTree::Token(syn::Token::Literal(syn::Lit::Str(ref string, _))) => string,
|
|
_ => panic!("expected string literal, got {:?}", token)
|
|
}
|
|
}
|