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::collections::HashSet;
29 use std::collections::BitvSet;
31 local_data_key!(used_attrs: BitvSet)
33 pub fn mark_used(attr: &Attribute) {
34 let mut used = used_attrs.replace(None).unwrap_or_else(|| BitvSet::new());
35 let AttrId(id) = attr.node.id;
37 used_attrs.replace(Some(used));
40 pub fn is_used(attr: &Attribute) -> bool {
41 let AttrId(id) = attr.node.id;
42 used_attrs.get().map_or(false, |used| used.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.as_slice()),
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>(&self, f: |&Attribute| -> T) -> T;
122 impl AttributeMethods for Attribute {
123 /// Extract the MetaItem from inside this Attribute.
124 fn meta<'a>(&'a self) -> &'a MetaItem {
128 /// Convert self to a normal #[doc="foo"] comment, if it is a
129 /// comment like `///` or `/** */`. (Returns self unchanged for
130 /// non-sugared doc attributes.)
131 fn with_desugared_doc<T>(&self, f: |&Attribute| -> T) -> T {
132 if self.node.is_sugared_doc {
133 let comment = self.value_str().unwrap();
134 let meta = mk_name_value_item_str(
135 InternedString::new("doc"),
136 token::intern_and_get_ident(strip_doc_comment_decoration(
137 comment.get()).as_slice()));
138 if self.node.style == ast::AttrOuter {
139 f(&mk_attr_outer(self.node.id, meta))
141 f(&mk_attr_inner(self.node.id, meta))
151 pub fn mk_name_value_item_str(name: InternedString, value: InternedString)
153 let value_lit = dummy_spanned(ast::LitStr(value, ast::CookedStr));
154 mk_name_value_item(name, value_lit)
157 pub fn mk_name_value_item(name: InternedString, value: ast::Lit)
159 P(dummy_spanned(MetaNameValue(name, value)))
162 pub fn mk_list_item(name: InternedString, items: Vec<P<MetaItem>>) -> P<MetaItem> {
163 P(dummy_spanned(MetaList(name, items)))
166 pub fn mk_word_item(name: InternedString) -> P<MetaItem> {
167 P(dummy_spanned(MetaWord(name)))
170 local_data_key!(next_attr_id: uint)
172 pub fn mk_attr_id() -> AttrId {
173 let id = next_attr_id.replace(None).unwrap_or(0);
174 next_attr_id.replace(Some(id + 1));
178 /// Returns an inner attribute with the given value.
179 pub fn mk_attr_inner(id: AttrId, item: P<MetaItem>) -> Attribute {
180 dummy_spanned(Attribute_ {
182 style: ast::AttrInner,
184 is_sugared_doc: false,
188 /// Returns an outer attribute with the given value.
189 pub fn mk_attr_outer(id: AttrId, item: P<MetaItem>) -> Attribute {
190 dummy_spanned(Attribute_ {
192 style: ast::AttrOuter,
194 is_sugared_doc: false,
198 pub fn mk_sugared_doc_attr(id: AttrId, text: InternedString, lo: BytePos,
201 let style = doc_comment_style(text.get());
202 let lit = spanned(lo, hi, ast::LitStr(text, ast::CookedStr));
203 let attr = Attribute_ {
206 value: P(spanned(lo, hi, MetaNameValue(InternedString::new("doc"),
210 spanned(lo, hi, attr)
214 /// Check if `needle` occurs in `haystack` by a structural
215 /// comparison. This is slightly subtle, and relies on ignoring the
216 /// span included in the `==` comparison a plain MetaItem.
217 pub fn contains(haystack: &[P<MetaItem>], needle: &MetaItem) -> bool {
218 debug!("attr::contains (name={})", needle.name());
219 haystack.iter().any(|item| {
220 debug!(" testing: {}", item.name());
221 item.node == needle.node
225 pub fn contains_name<AM: AttrMetaMethods>(metas: &[AM], name: &str) -> bool {
226 debug!("attr::contains_name (name={})", name);
227 metas.iter().any(|item| {
228 debug!(" testing: {}", item.name());
229 item.check_name(name)
233 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str)
234 -> Option<InternedString> {
236 .find(|at| at.check_name(name))
237 .and_then(|at| at.value_str())
240 pub fn last_meta_item_value_str_by_name(items: &[P<MetaItem>], name: &str)
241 -> Option<InternedString> {
244 .find(|mi| mi.check_name(name))
245 .and_then(|i| i.value_str())
248 /* Higher-level applications */
250 pub fn sort_meta_items(items: Vec<P<MetaItem>>) -> Vec<P<MetaItem>> {
251 // This is sort of stupid here, but we need to sort by
252 // human-readable strings.
253 let mut v = items.into_iter()
254 .map(|mi| (mi.name(), mi))
255 .collect::<Vec<(InternedString, P<MetaItem>)>>();
257 v.sort_by(|&(ref a, _), &(ref b, _)| a.cmp(b));
259 // There doesn't seem to be a more optimal way to do this
260 v.into_iter().map(|(_, m)| m.map(|Spanned {node, span}| {
263 MetaList(n, mis) => MetaList(n, sort_meta_items(mis)),
271 pub fn find_crate_name(attrs: &[Attribute]) -> Option<InternedString> {
272 first_attr_value_str_by_name(attrs, "crate_name")
275 #[deriving(PartialEq)]
276 pub enum InlineAttr {
283 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
284 pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
285 // FIXME (#2809)---validate the usage of #[inline] and #[inline]
286 attrs.iter().fold(InlineNone, |ia,attr| {
287 match attr.node.value.node {
288 MetaWord(ref n) if n.equiv(&("inline")) => {
292 MetaList(ref n, ref items) if n.equiv(&("inline")) => {
294 if contains_name(items.as_slice(), "always") {
296 } else if contains_name(items.as_slice(), "never") {
307 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
308 pub fn requests_inline(attrs: &[Attribute]) -> bool {
309 match find_inline_attr(attrs) {
310 InlineHint | InlineAlways => true,
311 InlineNone | InlineNever => false,
315 /// Tests if a cfg-pattern matches the cfg set
316 pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem) -> bool {
318 ast::MetaList(ref pred, ref mis) if pred.get() == "any" =>
319 mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
320 ast::MetaList(ref pred, ref mis) if pred.get() == "all" =>
321 mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
322 ast::MetaList(ref pred, ref mis) if pred.get() == "not" => {
324 diagnostic.span_err(cfg.span, "expected 1 cfg-pattern");
327 !cfg_matches(diagnostic, cfgs, &*mis[0])
329 ast::MetaList(ref pred, _) => {
330 diagnostic.span_err(cfg.span, format!("invalid predicate `{}`", pred).as_slice());
333 ast::MetaWord(_) | ast::MetaNameValue(..) => contains(cfgs, cfg),
337 /// Represents the #[deprecated="foo"] and friends attributes.
338 #[deriving(Encodable,Decodable,Clone,Show)]
339 pub struct Stability {
340 pub level: StabilityLevel,
341 pub text: Option<InternedString>
344 /// The available stability levels.
345 #[deriving(Encodable,Decodable,PartialEq,PartialOrd,Clone,Show)]
346 pub enum StabilityLevel {
355 pub fn find_stability_generic<'a,
359 -> Option<(Stability, &'a AM)> {
361 let level = match attr.name().get() {
362 "deprecated" => Deprecated,
363 "experimental" => Experimental,
364 "unstable" => Unstable,
368 _ => continue // not a stability level
371 return Some((Stability {
373 text: attr.value_str()
379 /// Find the first stability attribute. `None` if none exists.
380 pub fn find_stability(attrs: &[Attribute]) -> Option<Stability> {
381 find_stability_generic(attrs.iter()).map(|(s, attr)| {
387 pub fn require_unique_names(diagnostic: &SpanHandler, metas: &[P<MetaItem>]) {
388 let mut set = HashSet::new();
389 for meta in metas.iter() {
390 let name = meta.name();
392 if !set.insert(name.clone()) {
393 diagnostic.span_fatal(meta.span,
394 format!("duplicate meta item `{}`",
401 /// Parse #[repr(...)] forms.
403 /// Valid repr contents: any of the primitive integral type names (see
404 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
405 /// the same discriminant size that the corresponding C enum would or C
406 /// structure layout, and `packed` to remove padding.
407 pub fn find_repr_attrs(diagnostic: &SpanHandler, attr: &Attribute) -> Vec<ReprAttr> {
408 let mut acc = Vec::new();
409 match attr.node.value.node {
410 ast::MetaList(ref s, ref items) if s.equiv(&("repr")) => {
412 for item in items.iter() {
414 ast::MetaWord(ref word) => {
415 let hint = match word.get() {
416 // Can't use "extern" because it's not a lexical identifier.
417 "C" => Some(ReprExtern),
418 "packed" => Some(ReprPacked),
419 _ => match int_type_of_word(word.get()) {
420 Some(ity) => Some(ReprInt(item.span, ity)),
422 // Not a word we recognize
423 diagnostic.span_err(item.span,
424 "unrecognized representation hint");
431 Some(h) => acc.push(h),
436 _ => diagnostic.span_err(item.span, "unrecognized enum representation hint")
440 // Not a "repr" hint: ignore.
446 fn int_type_of_word(s: &str) -> Option<IntType> {
448 "i8" => Some(SignedInt(ast::TyI8)),
449 "u8" => Some(UnsignedInt(ast::TyU8)),
450 "i16" => Some(SignedInt(ast::TyI16)),
451 "u16" => Some(UnsignedInt(ast::TyU16)),
452 "i32" => Some(SignedInt(ast::TyI32)),
453 "u32" => Some(UnsignedInt(ast::TyU32)),
454 "i64" => Some(SignedInt(ast::TyI64)),
455 "u64" => Some(UnsignedInt(ast::TyU64)),
456 "int" => Some(SignedInt(ast::TyI)),
457 "uint" => Some(UnsignedInt(ast::TyU)),
462 #[deriving(PartialEq, Show, Encodable, Decodable)]
465 ReprInt(Span, IntType),
471 pub fn is_ffi_safe(&self) -> bool {
474 ReprInt(_sp, ity) => ity.is_ffi_safe(),
481 #[deriving(Eq, Hash, PartialEq, Show, Encodable, Decodable)]
483 SignedInt(ast::IntTy),
484 UnsignedInt(ast::UintTy)
489 pub fn is_signed(self) -> bool {
491 SignedInt(..) => true,
492 UnsignedInt(..) => false
495 fn is_ffi_safe(self) -> bool {
497 SignedInt(ast::TyI8) | UnsignedInt(ast::TyU8) |
498 SignedInt(ast::TyI16) | UnsignedInt(ast::TyU16) |
499 SignedInt(ast::TyI32) | UnsignedInt(ast::TyU32) |
500 SignedInt(ast::TyI64) | UnsignedInt(ast::TyU64) => true,
501 SignedInt(ast::TyI) | UnsignedInt(ast::TyU) => false