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
14 use ast::{AttrId, Attribute, Attribute_, MetaItem, MetaWord, MetaNameValue, MetaList};
15 use codemap::{Span, Spanned, spanned, dummy_spanned};
17 use diagnostic::SpanHandler;
18 use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
19 use parse::token::InternedString;
23 use std::collections::HashSet;
24 use std::collections::BitvSet;
26 local_data_key!(used_attrs: BitvSet)
28 pub fn mark_used(attr: &Attribute) {
29 let mut used = used_attrs.replace(None).unwrap_or_else(|| BitvSet::new());
30 let AttrId(id) = attr.node.id;
32 used_attrs.replace(Some(used));
35 pub fn is_used(attr: &Attribute) -> bool {
36 let AttrId(id) = attr.node.id;
37 used_attrs.get().map_or(false, |used| used.contains(&id))
40 pub trait AttrMetaMethods {
41 fn check_name(&self, name: &str) -> bool {
42 name == self.name().get()
45 /// Retrieve the name of the meta item, e.g. foo in #[foo],
46 /// #[foo="bar"] and #[foo(bar)]
47 fn name(&self) -> InternedString;
49 /// Gets the string value if self is a MetaNameValue variant
50 /// containing a string, otherwise None.
51 fn value_str(&self) -> Option<InternedString>;
52 /// Gets a list of inner meta items from a list MetaItem type.
53 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]>;
56 impl AttrMetaMethods for Attribute {
57 fn check_name(&self, name: &str) -> bool {
58 let matches = name == self.name().get();
64 fn name(&self) -> InternedString { self.meta().name() }
65 fn value_str(&self) -> Option<InternedString> {
66 self.meta().value_str()
68 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
69 self.node.value.meta_item_list()
73 impl AttrMetaMethods for MetaItem {
74 fn name(&self) -> InternedString {
76 MetaWord(ref n) => (*n).clone(),
77 MetaNameValue(ref n, _) => (*n).clone(),
78 MetaList(ref n, _) => (*n).clone(),
82 fn value_str(&self) -> Option<InternedString> {
84 MetaNameValue(_, ref v) => {
86 ast::LitStr(ref s, _) => Some((*s).clone()),
94 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
96 MetaList(_, ref l) => Some(l.as_slice()),
102 // Annoying, but required to get test_cfg to work
103 impl AttrMetaMethods for P<MetaItem> {
104 fn name(&self) -> InternedString { (**self).name() }
105 fn value_str(&self) -> Option<InternedString> { (**self).value_str() }
106 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
107 (**self).meta_item_list()
112 pub trait AttributeMethods {
113 fn meta<'a>(&'a self) -> &'a MetaItem;
114 fn with_desugared_doc<T>(&self, f: |&Attribute| -> T) -> T;
117 impl AttributeMethods for Attribute {
118 /// Extract the MetaItem from inside this Attribute.
119 fn meta<'a>(&'a self) -> &'a MetaItem {
123 /// Convert self to a normal #[doc="foo"] comment, if it is a
124 /// comment like `///` or `/** */`. (Returns self unchanged for
125 /// non-sugared doc attributes.)
126 fn with_desugared_doc<T>(&self, f: |&Attribute| -> T) -> T {
127 if self.node.is_sugared_doc {
128 let comment = self.value_str().unwrap();
129 let meta = mk_name_value_item_str(
130 InternedString::new("doc"),
131 token::intern_and_get_ident(strip_doc_comment_decoration(
132 comment.get()).as_slice()));
133 if self.node.style == ast::AttrOuter {
134 f(&mk_attr_outer(self.node.id, meta))
136 f(&mk_attr_inner(self.node.id, meta))
146 pub fn mk_name_value_item_str(name: InternedString, value: InternedString)
148 let value_lit = dummy_spanned(ast::LitStr(value, ast::CookedStr));
149 mk_name_value_item(name, value_lit)
152 pub fn mk_name_value_item(name: InternedString, value: ast::Lit)
154 P(dummy_spanned(MetaNameValue(name, value)))
157 pub fn mk_list_item(name: InternedString, items: Vec<P<MetaItem>>) -> P<MetaItem> {
158 P(dummy_spanned(MetaList(name, items)))
161 pub fn mk_word_item(name: InternedString) -> P<MetaItem> {
162 P(dummy_spanned(MetaWord(name)))
165 local_data_key!(next_attr_id: uint)
167 pub fn mk_attr_id() -> AttrId {
168 let id = next_attr_id.replace(None).unwrap_or(0);
169 next_attr_id.replace(Some(id + 1));
173 /// Returns an inner attribute with the given value.
174 pub fn mk_attr_inner(id: AttrId, item: P<MetaItem>) -> Attribute {
175 dummy_spanned(Attribute_ {
177 style: ast::AttrInner,
179 is_sugared_doc: false,
183 /// Returns an outer attribute with the given value.
184 pub fn mk_attr_outer(id: AttrId, item: P<MetaItem>) -> Attribute {
185 dummy_spanned(Attribute_ {
187 style: ast::AttrOuter,
189 is_sugared_doc: false,
193 pub fn mk_sugared_doc_attr(id: AttrId, text: InternedString, lo: BytePos,
196 let style = doc_comment_style(text.get());
197 let lit = spanned(lo, hi, ast::LitStr(text, ast::CookedStr));
198 let attr = Attribute_ {
201 value: P(spanned(lo, hi, MetaNameValue(InternedString::new("doc"),
205 spanned(lo, hi, attr)
209 /// Check if `needle` occurs in `haystack` by a structural
210 /// comparison. This is slightly subtle, and relies on ignoring the
211 /// span included in the `==` comparison a plain MetaItem.
212 pub fn contains(haystack: &[P<MetaItem>], needle: &MetaItem) -> bool {
213 debug!("attr::contains (name={})", needle.name());
214 haystack.iter().any(|item| {
215 debug!(" testing: {}", item.name());
216 item.node == needle.node
220 pub fn contains_name<AM: AttrMetaMethods>(metas: &[AM], name: &str) -> bool {
221 debug!("attr::contains_name (name={})", name);
222 metas.iter().any(|item| {
223 debug!(" testing: {}", item.name());
224 item.check_name(name)
228 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str)
229 -> Option<InternedString> {
231 .find(|at| at.check_name(name))
232 .and_then(|at| at.value_str())
235 pub fn last_meta_item_value_str_by_name(items: &[P<MetaItem>], name: &str)
236 -> Option<InternedString> {
239 .find(|mi| mi.check_name(name))
240 .and_then(|i| i.value_str())
243 /* Higher-level applications */
245 pub fn sort_meta_items(items: Vec<P<MetaItem>>) -> Vec<P<MetaItem>> {
246 // This is sort of stupid here, but we need to sort by
247 // human-readable strings.
248 let mut v = items.into_iter()
249 .map(|mi| (mi.name(), mi))
250 .collect::<Vec<(InternedString, P<MetaItem>)>>();
252 v.sort_by(|&(ref a, _), &(ref b, _)| a.cmp(b));
254 // There doesn't seem to be a more optimal way to do this
255 v.into_iter().map(|(_, m)| m.map(|Spanned {node, span}| {
258 MetaList(n, mis) => MetaList(n, sort_meta_items(mis)),
266 pub fn find_crate_name(attrs: &[Attribute]) -> Option<InternedString> {
267 first_attr_value_str_by_name(attrs, "crate_name")
270 #[deriving(PartialEq)]
271 pub enum InlineAttr {
278 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
279 pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
280 // FIXME (#2809)---validate the usage of #[inline] and #[inline]
281 attrs.iter().fold(InlineNone, |ia,attr| {
282 match attr.node.value.node {
283 MetaWord(ref n) if n.equiv(&("inline")) => {
287 MetaList(ref n, ref items) if n.equiv(&("inline")) => {
289 if contains_name(items.as_slice(), "always") {
291 } else if contains_name(items.as_slice(), "never") {
302 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
303 pub fn requests_inline(attrs: &[Attribute]) -> bool {
304 match find_inline_attr(attrs) {
305 InlineHint | InlineAlways => true,
306 InlineNone | InlineNever => false,
310 /// Tests if a cfg-pattern matches the cfg set
311 pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem) -> bool {
313 ast::MetaList(ref pred, ref mis) if pred.get() == "any" =>
314 mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
315 ast::MetaList(ref pred, ref mis) if pred.get() == "all" =>
316 mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
317 ast::MetaList(ref pred, ref mis) if pred.get() == "not" => {
319 diagnostic.span_warn(cfg.span, "the use of multiple cfgs in the same `not` \
320 statement is deprecated. Change `not(a, b)` to \
323 !mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi))
325 ast::MetaList(ref pred, _) => {
326 diagnostic.span_err(cfg.span, format!("invalid predicate `{}`", pred).as_slice());
329 ast::MetaWord(_) | ast::MetaNameValue(..) => contains(cfgs, cfg),
333 /// Tests if any `cfg(...)` meta items in `metas` match `cfg`. e.g.
335 /// test_cfg(`[foo="a", bar]`, `[cfg(foo), cfg(bar)]`) == true
336 /// test_cfg(`[foo="a", bar]`, `[cfg(not(bar))]`) == false
337 /// test_cfg(`[foo="a", bar]`, `[cfg(bar, foo="a")]`) == true
338 /// test_cfg(`[foo="a", bar]`, `[cfg(bar, foo="b")]`) == false
339 pub fn test_cfg<'a, AM: AttrMetaMethods, It: Iterator<&'a AM>>
340 (cfg: &[P<MetaItem>], mut metas: It) -> bool {
341 // having no #[cfg(...)] attributes counts as matching.
342 let mut no_cfgs = true;
344 // this would be much nicer as a chain of iterator adaptors, but
345 // this doesn't work.
346 let some_cfg_matches = metas.fold(false, |matches, mi| {
347 debug!("testing name: {}", mi.name());
348 let this_matches = if mi.check_name("cfg") { // it is a #[cfg()] attribute
351 // only #[cfg(...)] ones are understood.
352 match mi.meta_item_list() {
354 debug!("is cfg(...)");
355 cfg_meta.iter().all(|cfg_mi| {
356 debug!("cfg({}[...])", cfg_mi.name());
358 ast::MetaList(ref s, ref not_cfgs)
359 if s.equiv(&("not")) => {
361 // inside #[cfg(not(...))], so these need to all
363 !not_cfgs.iter().all(|mi| {
364 debug!("cfg(not({}[...]))", mi.name());
368 _ => contains(cfg, &**cfg_mi)
377 matches || this_matches
379 debug!("test_cfg (no_cfgs={}, some_cfg_matches={})", no_cfgs, some_cfg_matches);
380 no_cfgs || some_cfg_matches
383 /// Represents the #[deprecated="foo"] and friends attributes.
384 #[deriving(Encodable,Decodable,Clone,Show)]
385 pub struct Stability {
386 pub level: StabilityLevel,
387 pub text: Option<InternedString>
390 /// The available stability levels.
391 #[deriving(Encodable,Decodable,PartialEq,PartialOrd,Clone,Show)]
392 pub enum StabilityLevel {
401 pub fn find_stability_generic<'a,
405 -> Option<(Stability, &'a AM)> {
407 let level = match attr.name().get() {
408 "deprecated" => Deprecated,
409 "experimental" => Experimental,
410 "unstable" => Unstable,
414 _ => continue // not a stability level
417 return Some((Stability {
419 text: attr.value_str()
425 /// Find the first stability attribute. `None` if none exists.
426 pub fn find_stability(attrs: &[Attribute]) -> Option<Stability> {
427 find_stability_generic(attrs.iter()).map(|(s, attr)| {
433 pub fn require_unique_names(diagnostic: &SpanHandler, metas: &[P<MetaItem>]) {
434 let mut set = HashSet::new();
435 for meta in metas.iter() {
436 let name = meta.name();
438 if !set.insert(name.clone()) {
439 diagnostic.span_fatal(meta.span,
440 format!("duplicate meta item `{}`",
447 /// Parse #[repr(...)] forms.
449 /// Valid repr contents: any of the primitive integral type names (see
450 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
451 /// the same discriminant size that the corresponding C enum would or C
452 /// structure layout, and `packed` to remove padding.
453 pub fn find_repr_attrs(diagnostic: &SpanHandler, attr: &Attribute) -> Vec<ReprAttr> {
454 let mut acc = Vec::new();
455 match attr.node.value.node {
456 ast::MetaList(ref s, ref items) if s.equiv(&("repr")) => {
458 for item in items.iter() {
460 ast::MetaWord(ref word) => {
461 let hint = match word.get() {
462 // Can't use "extern" because it's not a lexical identifier.
463 "C" => Some(ReprExtern),
464 "packed" => Some(ReprPacked),
465 _ => match int_type_of_word(word.get()) {
466 Some(ity) => Some(ReprInt(item.span, ity)),
468 // Not a word we recognize
469 diagnostic.span_err(item.span,
470 "unrecognized representation hint");
477 Some(h) => acc.push(h),
482 _ => diagnostic.span_err(item.span, "unrecognized enum representation hint")
486 // Not a "repr" hint: ignore.
492 fn int_type_of_word(s: &str) -> Option<IntType> {
494 "i8" => Some(SignedInt(ast::TyI8)),
495 "u8" => Some(UnsignedInt(ast::TyU8)),
496 "i16" => Some(SignedInt(ast::TyI16)),
497 "u16" => Some(UnsignedInt(ast::TyU16)),
498 "i32" => Some(SignedInt(ast::TyI32)),
499 "u32" => Some(UnsignedInt(ast::TyU32)),
500 "i64" => Some(SignedInt(ast::TyI64)),
501 "u64" => Some(UnsignedInt(ast::TyU64)),
502 "int" => Some(SignedInt(ast::TyI)),
503 "uint" => Some(UnsignedInt(ast::TyU)),
508 #[deriving(PartialEq, Show, Encodable, Decodable)]
511 ReprInt(Span, IntType),
517 pub fn is_ffi_safe(&self) -> bool {
520 ReprInt(_sp, ity) => ity.is_ffi_safe(),
527 #[deriving(Eq, Hash, PartialEq, Show, Encodable, Decodable)]
529 SignedInt(ast::IntTy),
530 UnsignedInt(ast::UintTy)
535 pub fn is_signed(self) -> bool {
537 SignedInt(..) => true,
538 UnsignedInt(..) => false
541 fn is_ffi_safe(self) -> bool {
543 SignedInt(ast::TyI8) | UnsignedInt(ast::TyU8) |
544 SignedInt(ast::TyI16) | UnsignedInt(ast::TyU16) |
545 SignedInt(ast::TyI32) | UnsignedInt(ast::TyU32) |
546 SignedInt(ast::TyI64) | UnsignedInt(ast::TyU64) => true,
547 SignedInt(ast::TyI) | UnsignedInt(ast::TyU) => false