1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Functions dealing with attributes and meta items
13 pub use self::InlineAttr::*;
14 pub use self::StabilityLevel::*;
15 pub use self::ReprAttr::*;
16 pub use self::IntType::*;
19 use ast::{AttrId, Attribute, Attribute_, MetaItem, MetaWord, MetaNameValue, MetaList};
20 use codemap::{Span, Spanned, spanned, dummy_spanned};
22 use diagnostic::SpanHandler;
23 use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
24 use parse::token::InternedString;
28 use std::cell::{RefCell, Cell};
29 use std::collections::BitvSet;
30 use std::collections::HashSet;
33 thread_local! { static USED_ATTRS: RefCell<BitvSet> = RefCell::new(BitvSet::new()) }
35 pub fn mark_used(attr: &Attribute) {
36 let AttrId(id) = attr.node.id;
37 USED_ATTRS.with(|slot| slot.borrow_mut().insert(id));
40 pub fn is_used(attr: &Attribute) -> bool {
41 let AttrId(id) = attr.node.id;
42 USED_ATTRS.with(|slot| slot.borrow().contains(&id))
45 pub trait AttrMetaMethods {
46 fn check_name(&self, name: &str) -> bool {
47 name == self.name().get()
50 /// Retrieve the name of the meta item, e.g. `foo` in `#[foo]`,
51 /// `#[foo="bar"]` and `#[foo(bar)]`
52 fn name(&self) -> InternedString;
54 /// Gets the string value if self is a MetaNameValue variant
55 /// containing a string, otherwise None.
56 fn value_str(&self) -> Option<InternedString>;
57 /// Gets a list of inner meta items from a list MetaItem type.
58 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]>;
61 impl AttrMetaMethods for Attribute {
62 fn check_name(&self, name: &str) -> bool {
63 let matches = name == self.name().get();
69 fn name(&self) -> InternedString { self.meta().name() }
70 fn value_str(&self) -> Option<InternedString> {
71 self.meta().value_str()
73 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
74 self.node.value.meta_item_list()
78 impl AttrMetaMethods for MetaItem {
79 fn name(&self) -> InternedString {
81 MetaWord(ref n) => (*n).clone(),
82 MetaNameValue(ref n, _) => (*n).clone(),
83 MetaList(ref n, _) => (*n).clone(),
87 fn value_str(&self) -> Option<InternedString> {
89 MetaNameValue(_, ref v) => {
91 ast::LitStr(ref s, _) => Some((*s).clone()),
99 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
101 MetaList(_, ref l) => Some(&l[]),
107 // Annoying, but required to get test_cfg to work
108 impl AttrMetaMethods for P<MetaItem> {
109 fn name(&self) -> InternedString { (**self).name() }
110 fn value_str(&self) -> Option<InternedString> { (**self).value_str() }
111 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
112 (**self).meta_item_list()
117 pub trait AttributeMethods {
118 fn meta<'a>(&'a self) -> &'a MetaItem;
119 fn with_desugared_doc<T, F>(&self, f: F) -> T where
120 F: FnOnce(&Attribute) -> T;
123 impl AttributeMethods for Attribute {
124 /// Extract the MetaItem from inside this Attribute.
125 fn meta<'a>(&'a self) -> &'a MetaItem {
129 /// Convert self to a normal #[doc="foo"] comment, if it is a
130 /// comment like `///` or `/** */`. (Returns self unchanged for
131 /// non-sugared doc attributes.)
132 fn with_desugared_doc<T, F>(&self, f: F) -> T where
133 F: FnOnce(&Attribute) -> T,
135 if self.node.is_sugared_doc {
136 let comment = self.value_str().unwrap();
137 let meta = mk_name_value_item_str(
138 InternedString::new("doc"),
139 token::intern_and_get_ident(&strip_doc_comment_decoration(
141 if self.node.style == ast::AttrOuter {
142 f(&mk_attr_outer(self.node.id, meta))
144 f(&mk_attr_inner(self.node.id, meta))
154 pub fn mk_name_value_item_str(name: InternedString, value: InternedString)
156 let value_lit = dummy_spanned(ast::LitStr(value, ast::CookedStr));
157 mk_name_value_item(name, value_lit)
160 pub fn mk_name_value_item(name: InternedString, value: ast::Lit)
162 P(dummy_spanned(MetaNameValue(name, value)))
165 pub fn mk_list_item(name: InternedString, items: Vec<P<MetaItem>>) -> P<MetaItem> {
166 P(dummy_spanned(MetaList(name, items)))
169 pub fn mk_word_item(name: InternedString) -> P<MetaItem> {
170 P(dummy_spanned(MetaWord(name)))
173 thread_local! { static NEXT_ATTR_ID: Cell<usize> = Cell::new(0) }
175 pub fn mk_attr_id() -> AttrId {
176 let id = NEXT_ATTR_ID.with(|slot| {
184 /// Returns an inner attribute with the given value.
185 pub fn mk_attr_inner(id: AttrId, item: P<MetaItem>) -> Attribute {
186 dummy_spanned(Attribute_ {
188 style: ast::AttrInner,
190 is_sugared_doc: false,
194 /// Returns an outer attribute with the given value.
195 pub fn mk_attr_outer(id: AttrId, item: P<MetaItem>) -> Attribute {
196 dummy_spanned(Attribute_ {
198 style: ast::AttrOuter,
200 is_sugared_doc: false,
204 pub fn mk_sugared_doc_attr(id: AttrId, text: InternedString, lo: BytePos,
207 let style = doc_comment_style(text.get());
208 let lit = spanned(lo, hi, ast::LitStr(text, ast::CookedStr));
209 let attr = Attribute_ {
212 value: P(spanned(lo, hi, MetaNameValue(InternedString::new("doc"),
216 spanned(lo, hi, attr)
220 /// Check if `needle` occurs in `haystack` by a structural
221 /// comparison. This is slightly subtle, and relies on ignoring the
222 /// span included in the `==` comparison a plain MetaItem.
223 pub fn contains(haystack: &[P<MetaItem>], needle: &MetaItem) -> bool {
224 debug!("attr::contains (name={})", needle.name());
225 haystack.iter().any(|item| {
226 debug!(" testing: {}", item.name());
227 item.node == needle.node
231 pub fn contains_name<AM: AttrMetaMethods>(metas: &[AM], name: &str) -> bool {
232 debug!("attr::contains_name (name={})", name);
233 metas.iter().any(|item| {
234 debug!(" testing: {}", item.name());
235 item.check_name(name)
239 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str)
240 -> Option<InternedString> {
242 .find(|at| at.check_name(name))
243 .and_then(|at| at.value_str())
246 pub fn last_meta_item_value_str_by_name(items: &[P<MetaItem>], name: &str)
247 -> Option<InternedString> {
250 .find(|mi| mi.check_name(name))
251 .and_then(|i| i.value_str())
254 /* Higher-level applications */
256 pub fn sort_meta_items(items: Vec<P<MetaItem>>) -> Vec<P<MetaItem>> {
257 // This is sort of stupid here, but we need to sort by
258 // human-readable strings.
259 let mut v = items.into_iter()
260 .map(|mi| (mi.name(), mi))
261 .collect::<Vec<(InternedString, P<MetaItem>)>>();
263 v.sort_by(|&(ref a, _), &(ref b, _)| a.cmp(b));
265 // There doesn't seem to be a more optimal way to do this
266 v.into_iter().map(|(_, m)| m.map(|Spanned {node, span}| {
269 MetaList(n, mis) => MetaList(n, sort_meta_items(mis)),
277 pub fn find_crate_name(attrs: &[Attribute]) -> Option<InternedString> {
278 first_attr_value_str_by_name(attrs, "crate_name")
281 #[derive(Copy, PartialEq)]
282 pub enum InlineAttr {
289 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
290 pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
291 // FIXME (#2809)---validate the usage of #[inline] and #[inline]
292 attrs.iter().fold(InlineNone, |ia,attr| {
293 match attr.node.value.node {
294 MetaWord(ref n) if *n == "inline" => {
298 MetaList(ref n, ref items) if *n == "inline" => {
300 if contains_name(&items[], "always") {
302 } else if contains_name(&items[], "never") {
313 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
314 pub fn requests_inline(attrs: &[Attribute]) -> bool {
315 match find_inline_attr(attrs) {
316 InlineHint | InlineAlways => true,
317 InlineNone | InlineNever => false,
321 /// Tests if a cfg-pattern matches the cfg set
322 pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem) -> bool {
324 ast::MetaList(ref pred, ref mis) if pred.get() == "any" =>
325 mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
326 ast::MetaList(ref pred, ref mis) if pred.get() == "all" =>
327 mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
328 ast::MetaList(ref pred, ref mis) if pred.get() == "not" => {
330 diagnostic.span_err(cfg.span, "expected 1 cfg-pattern");
333 !cfg_matches(diagnostic, cfgs, &*mis[0])
335 ast::MetaList(ref pred, _) => {
336 diagnostic.span_err(cfg.span, format!("invalid predicate `{}`", pred).as_slice());
339 ast::MetaWord(_) | ast::MetaNameValue(..) => contains(cfgs, cfg),
343 /// Represents the #[deprecated="foo"] and friends attributes.
344 #[derive(RustcEncodable,RustcDecodable,Clone,Show)]
345 pub struct Stability {
346 pub level: StabilityLevel,
347 pub text: Option<InternedString>
350 /// The available stability levels.
351 #[derive(RustcEncodable,RustcDecodable,PartialEq,PartialOrd,Clone,Show,Copy)]
352 pub enum StabilityLevel {
361 impl fmt::String for StabilityLevel {
362 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
363 fmt::Show::fmt(self, f)
367 pub fn find_stability_generic<'a,
369 I: Iterator<Item=&'a AM>>
371 -> Option<(Stability, &'a AM)> {
373 let level = match attr.name().get() {
374 "deprecated" => Deprecated,
375 "experimental" => Experimental,
376 "unstable" => Unstable,
380 _ => continue // not a stability level
383 return Some((Stability {
385 text: attr.value_str()
391 /// Find the first stability attribute. `None` if none exists.
392 pub fn find_stability(attrs: &[Attribute]) -> Option<Stability> {
393 find_stability_generic(attrs.iter()).map(|(s, attr)| {
399 pub fn require_unique_names(diagnostic: &SpanHandler, metas: &[P<MetaItem>]) {
400 let mut set = HashSet::new();
401 for meta in metas.iter() {
402 let name = meta.name();
404 if !set.insert(name.clone()) {
405 diagnostic.span_fatal(meta.span,
406 &format!("duplicate meta item `{}`", name)[]);
412 /// Parse #[repr(...)] forms.
414 /// Valid repr contents: any of the primitive integral type names (see
415 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
416 /// the same discriminant size that the corresponding C enum would or C
417 /// structure layout, and `packed` to remove padding.
418 pub fn find_repr_attrs(diagnostic: &SpanHandler, attr: &Attribute) -> Vec<ReprAttr> {
419 let mut acc = Vec::new();
420 match attr.node.value.node {
421 ast::MetaList(ref s, ref items) if *s == "repr" => {
423 for item in items.iter() {
425 ast::MetaWord(ref word) => {
426 let hint = match word.get() {
427 // Can't use "extern" because it's not a lexical identifier.
428 "C" => Some(ReprExtern),
429 "packed" => Some(ReprPacked),
430 _ => match int_type_of_word(word.get()) {
431 Some(ity) => Some(ReprInt(item.span, ity)),
433 // Not a word we recognize
434 diagnostic.span_err(item.span,
435 "unrecognized representation hint");
442 Some(h) => acc.push(h),
447 _ => diagnostic.span_err(item.span, "unrecognized enum representation hint")
451 // Not a "repr" hint: ignore.
457 fn int_type_of_word(s: &str) -> Option<IntType> {
459 "i8" => Some(SignedInt(ast::TyI8)),
460 "u8" => Some(UnsignedInt(ast::TyU8)),
461 "i16" => Some(SignedInt(ast::TyI16)),
462 "u16" => Some(UnsignedInt(ast::TyU16)),
463 "i32" => Some(SignedInt(ast::TyI32)),
464 "u32" => Some(UnsignedInt(ast::TyU32)),
465 "i64" => Some(SignedInt(ast::TyI64)),
466 "u64" => Some(UnsignedInt(ast::TyU64)),
467 "int" => Some(SignedInt(ast::TyIs(true))),
468 "uint" => Some(UnsignedInt(ast::TyUs(true))),
469 "isize" => Some(SignedInt(ast::TyIs(false))),
470 "usize" => Some(UnsignedInt(ast::TyUs(false))),
475 #[derive(PartialEq, Show, RustcEncodable, RustcDecodable, Copy)]
478 ReprInt(Span, IntType),
484 pub fn is_ffi_safe(&self) -> bool {
487 ReprInt(_sp, ity) => ity.is_ffi_safe(),
494 #[derive(Eq, Hash, PartialEq, Show, RustcEncodable, RustcDecodable, Copy)]
496 SignedInt(ast::IntTy),
497 UnsignedInt(ast::UintTy)
502 pub fn is_signed(self) -> bool {
504 SignedInt(..) => true,
505 UnsignedInt(..) => false
508 fn is_ffi_safe(self) -> bool {
510 SignedInt(ast::TyI8) | UnsignedInt(ast::TyU8) |
511 SignedInt(ast::TyI16) | UnsignedInt(ast::TyU16) |
512 SignedInt(ast::TyI32) | UnsignedInt(ast::TyU32) |
513 SignedInt(ast::TyI64) | UnsignedInt(ast::TyU64) => true,
514 SignedInt(ast::TyIs(_)) | UnsignedInt(ast::TyUs(_)) => false