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;
32 thread_local!(static USED_ATTRS: RefCell<BitvSet> = RefCell::new(BitvSet::new()))
34 pub fn mark_used(attr: &Attribute) {
35 let AttrId(id) = attr.node.id;
36 USED_ATTRS.with(|slot| slot.borrow_mut().insert(id));
39 pub fn is_used(attr: &Attribute) -> bool {
40 let AttrId(id) = attr.node.id;
41 USED_ATTRS.with(|slot| slot.borrow().contains(&id))
44 pub trait AttrMetaMethods {
45 fn check_name(&self, name: &str) -> bool {
46 name == self.name().get()
49 /// Retrieve the name of the meta item, e.g. `foo` in `#[foo]`,
50 /// `#[foo="bar"]` and `#[foo(bar)]`
51 fn name(&self) -> InternedString;
53 /// Gets the string value if self is a MetaNameValue variant
54 /// containing a string, otherwise None.
55 fn value_str(&self) -> Option<InternedString>;
56 /// Gets a list of inner meta items from a list MetaItem type.
57 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]>;
60 impl AttrMetaMethods for Attribute {
61 fn check_name(&self, name: &str) -> bool {
62 let matches = name == self.name().get();
68 fn name(&self) -> InternedString { self.meta().name() }
69 fn value_str(&self) -> Option<InternedString> {
70 self.meta().value_str()
72 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
73 self.node.value.meta_item_list()
77 impl AttrMetaMethods for MetaItem {
78 fn name(&self) -> InternedString {
80 MetaWord(ref n) => (*n).clone(),
81 MetaNameValue(ref n, _) => (*n).clone(),
82 MetaList(ref n, _) => (*n).clone(),
86 fn value_str(&self) -> Option<InternedString> {
88 MetaNameValue(_, ref v) => {
90 ast::LitStr(ref s, _) => Some((*s).clone()),
98 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
100 MetaList(_, ref l) => Some(l.as_slice()),
106 // Annoying, but required to get test_cfg to work
107 impl AttrMetaMethods for P<MetaItem> {
108 fn name(&self) -> InternedString { (**self).name() }
109 fn value_str(&self) -> Option<InternedString> { (**self).value_str() }
110 fn meta_item_list<'a>(&'a self) -> Option<&'a [P<MetaItem>]> {
111 (**self).meta_item_list()
116 pub trait AttributeMethods {
117 fn meta<'a>(&'a self) -> &'a MetaItem;
118 fn with_desugared_doc<T>(&self, f: |&Attribute| -> T) -> T;
121 impl AttributeMethods for Attribute {
122 /// Extract the MetaItem from inside this Attribute.
123 fn meta<'a>(&'a self) -> &'a MetaItem {
127 /// Convert self to a normal #[doc="foo"] comment, if it is a
128 /// comment like `///` or `/** */`. (Returns self unchanged for
129 /// non-sugared doc attributes.)
130 fn with_desugared_doc<T>(&self, f: |&Attribute| -> T) -> T {
131 if self.node.is_sugared_doc {
132 let comment = self.value_str().unwrap();
133 let meta = mk_name_value_item_str(
134 InternedString::new("doc"),
135 token::intern_and_get_ident(strip_doc_comment_decoration(
136 comment.get()).as_slice()));
137 if self.node.style == ast::AttrOuter {
138 f(&mk_attr_outer(self.node.id, meta))
140 f(&mk_attr_inner(self.node.id, meta))
150 pub fn mk_name_value_item_str(name: InternedString, value: InternedString)
152 let value_lit = dummy_spanned(ast::LitStr(value, ast::CookedStr));
153 mk_name_value_item(name, value_lit)
156 pub fn mk_name_value_item(name: InternedString, value: ast::Lit)
158 P(dummy_spanned(MetaNameValue(name, value)))
161 pub fn mk_list_item(name: InternedString, items: Vec<P<MetaItem>>) -> P<MetaItem> {
162 P(dummy_spanned(MetaList(name, items)))
165 pub fn mk_word_item(name: InternedString) -> P<MetaItem> {
166 P(dummy_spanned(MetaWord(name)))
169 thread_local!(static NEXT_ATTR_ID: Cell<uint> = Cell::new(0))
171 pub fn mk_attr_id() -> AttrId {
172 let id = NEXT_ATTR_ID.with(|slot| {
180 /// Returns an inner attribute with the given value.
181 pub fn mk_attr_inner(id: AttrId, item: P<MetaItem>) -> Attribute {
182 dummy_spanned(Attribute_ {
184 style: ast::AttrInner,
186 is_sugared_doc: false,
190 /// Returns an outer attribute with the given value.
191 pub fn mk_attr_outer(id: AttrId, item: P<MetaItem>) -> Attribute {
192 dummy_spanned(Attribute_ {
194 style: ast::AttrOuter,
196 is_sugared_doc: false,
200 pub fn mk_sugared_doc_attr(id: AttrId, text: InternedString, lo: BytePos,
203 let style = doc_comment_style(text.get());
204 let lit = spanned(lo, hi, ast::LitStr(text, ast::CookedStr));
205 let attr = Attribute_ {
208 value: P(spanned(lo, hi, MetaNameValue(InternedString::new("doc"),
212 spanned(lo, hi, attr)
216 /// Check if `needle` occurs in `haystack` by a structural
217 /// comparison. This is slightly subtle, and relies on ignoring the
218 /// span included in the `==` comparison a plain MetaItem.
219 pub fn contains(haystack: &[P<MetaItem>], needle: &MetaItem) -> bool {
220 debug!("attr::contains (name={})", needle.name());
221 haystack.iter().any(|item| {
222 debug!(" testing: {}", item.name());
223 item.node == needle.node
227 pub fn contains_name<AM: AttrMetaMethods>(metas: &[AM], name: &str) -> bool {
228 debug!("attr::contains_name (name={})", name);
229 metas.iter().any(|item| {
230 debug!(" testing: {}", item.name());
231 item.check_name(name)
235 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str)
236 -> Option<InternedString> {
238 .find(|at| at.check_name(name))
239 .and_then(|at| at.value_str())
242 pub fn last_meta_item_value_str_by_name(items: &[P<MetaItem>], name: &str)
243 -> Option<InternedString> {
246 .find(|mi| mi.check_name(name))
247 .and_then(|i| i.value_str())
250 /* Higher-level applications */
252 pub fn sort_meta_items(items: Vec<P<MetaItem>>) -> Vec<P<MetaItem>> {
253 // This is sort of stupid here, but we need to sort by
254 // human-readable strings.
255 let mut v = items.into_iter()
256 .map(|mi| (mi.name(), mi))
257 .collect::<Vec<(InternedString, P<MetaItem>)>>();
259 v.sort_by(|&(ref a, _), &(ref b, _)| a.cmp(b));
261 // There doesn't seem to be a more optimal way to do this
262 v.into_iter().map(|(_, m)| m.map(|Spanned {node, span}| {
265 MetaList(n, mis) => MetaList(n, sort_meta_items(mis)),
273 pub fn find_crate_name(attrs: &[Attribute]) -> Option<InternedString> {
274 first_attr_value_str_by_name(attrs, "crate_name")
277 #[deriving(PartialEq)]
278 pub enum InlineAttr {
285 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
286 pub fn find_inline_attr(attrs: &[Attribute]) -> InlineAttr {
287 // FIXME (#2809)---validate the usage of #[inline] and #[inline]
288 attrs.iter().fold(InlineNone, |ia,attr| {
289 match attr.node.value.node {
290 MetaWord(ref n) if *n == "inline" => {
294 MetaList(ref n, ref items) if *n == "inline" => {
296 if contains_name(items.as_slice(), "always") {
298 } else if contains_name(items.as_slice(), "never") {
309 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
310 pub fn requests_inline(attrs: &[Attribute]) -> bool {
311 match find_inline_attr(attrs) {
312 InlineHint | InlineAlways => true,
313 InlineNone | InlineNever => false,
317 /// Tests if a cfg-pattern matches the cfg set
318 pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem) -> bool {
320 ast::MetaList(ref pred, ref mis) if pred.get() == "any" =>
321 mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
322 ast::MetaList(ref pred, ref mis) if pred.get() == "all" =>
323 mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
324 ast::MetaList(ref pred, ref mis) if pred.get() == "not" => {
326 diagnostic.span_err(cfg.span, "expected 1 cfg-pattern");
329 !cfg_matches(diagnostic, cfgs, &*mis[0])
331 ast::MetaList(ref pred, _) => {
332 diagnostic.span_err(cfg.span, format!("invalid predicate `{}`", pred).as_slice());
335 ast::MetaWord(_) | ast::MetaNameValue(..) => contains(cfgs, cfg),
339 /// Represents the #[deprecated="foo"] and friends attributes.
340 #[deriving(Encodable,Decodable,Clone,Show)]
341 pub struct Stability {
342 pub level: StabilityLevel,
343 pub text: Option<InternedString>
346 /// The available stability levels.
347 #[deriving(Encodable,Decodable,PartialEq,PartialOrd,Clone,Show)]
348 pub enum StabilityLevel {
357 pub fn find_stability_generic<'a,
361 -> Option<(Stability, &'a AM)> {
363 let level = match attr.name().get() {
364 "deprecated" => Deprecated,
365 "experimental" => Experimental,
366 "unstable" => Unstable,
370 _ => continue // not a stability level
373 return Some((Stability {
375 text: attr.value_str()
381 /// Find the first stability attribute. `None` if none exists.
382 pub fn find_stability(attrs: &[Attribute]) -> Option<Stability> {
383 find_stability_generic(attrs.iter()).map(|(s, attr)| {
389 pub fn require_unique_names(diagnostic: &SpanHandler, metas: &[P<MetaItem>]) {
390 let mut set = HashSet::new();
391 for meta in metas.iter() {
392 let name = meta.name();
394 if !set.insert(name.clone()) {
395 diagnostic.span_fatal(meta.span,
396 format!("duplicate meta item `{}`",
403 /// Parse #[repr(...)] forms.
405 /// Valid repr contents: any of the primitive integral type names (see
406 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
407 /// the same discriminant size that the corresponding C enum would or C
408 /// structure layout, and `packed` to remove padding.
409 pub fn find_repr_attrs(diagnostic: &SpanHandler, attr: &Attribute) -> Vec<ReprAttr> {
410 let mut acc = Vec::new();
411 match attr.node.value.node {
412 ast::MetaList(ref s, ref items) if *s == "repr" => {
414 for item in items.iter() {
416 ast::MetaWord(ref word) => {
417 let hint = match word.get() {
418 // Can't use "extern" because it's not a lexical identifier.
419 "C" => Some(ReprExtern),
420 "packed" => Some(ReprPacked),
421 _ => match int_type_of_word(word.get()) {
422 Some(ity) => Some(ReprInt(item.span, ity)),
424 // Not a word we recognize
425 diagnostic.span_err(item.span,
426 "unrecognized representation hint");
433 Some(h) => acc.push(h),
438 _ => diagnostic.span_err(item.span, "unrecognized enum representation hint")
442 // Not a "repr" hint: ignore.
448 fn int_type_of_word(s: &str) -> Option<IntType> {
450 "i8" => Some(SignedInt(ast::TyI8)),
451 "u8" => Some(UnsignedInt(ast::TyU8)),
452 "i16" => Some(SignedInt(ast::TyI16)),
453 "u16" => Some(UnsignedInt(ast::TyU16)),
454 "i32" => Some(SignedInt(ast::TyI32)),
455 "u32" => Some(UnsignedInt(ast::TyU32)),
456 "i64" => Some(SignedInt(ast::TyI64)),
457 "u64" => Some(UnsignedInt(ast::TyU64)),
458 "int" => Some(SignedInt(ast::TyI)),
459 "uint" => Some(UnsignedInt(ast::TyU)),
464 #[deriving(PartialEq, Show, Encodable, Decodable)]
467 ReprInt(Span, IntType),
473 pub fn is_ffi_safe(&self) -> bool {
476 ReprInt(_sp, ity) => ity.is_ffi_safe(),
483 #[deriving(Eq, Hash, PartialEq, Show, Encodable, Decodable)]
485 SignedInt(ast::IntTy),
486 UnsignedInt(ast::UintTy)
491 pub fn is_signed(self) -> bool {
493 SignedInt(..) => true,
494 UnsignedInt(..) => false
497 fn is_ffi_safe(self) -> bool {
499 SignedInt(ast::TyI8) | UnsignedInt(ast::TyU8) |
500 SignedInt(ast::TyI16) | UnsignedInt(ast::TyU16) |
501 SignedInt(ast::TyI32) | UnsignedInt(ast::TyU32) |
502 SignedInt(ast::TyI64) | UnsignedInt(ast::TyU64) => true,
503 SignedInt(ast::TyI) | UnsignedInt(ast::TyU) => false