rust/src/libsyntax/attr.rs

1344 lines
46 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Functions dealing with attributes and meta items
pub use self::StabilityLevel::*;
pub use self::ReprAttr::*;
pub use self::IntType::*;
use ast;
use ast::{AttrId, Attribute, Name, Ident};
use ast::{MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
use ast::{Lit, LitKind, Expr, ExprKind, Item, Local, Stmt, StmtKind};
use codemap::{Spanned, respan, dummy_spanned};
use syntax_pos::{Span, DUMMY_SP};
use errors::Handler;
use feature_gate::{Features, GatedCfg};
use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
use parse::parser::Parser;
use parse::{self, ParseSess, PResult};
use parse::token::{self, Token};
use ptr::P;
use symbol::Symbol;
use tokenstream::{TokenStream, TokenTree, Delimited};
use util::ThinVec;
use std::cell::{RefCell, Cell};
use std::iter;
thread_local! {
static USED_ATTRS: RefCell<Vec<u64>> = RefCell::new(Vec::new());
static KNOWN_ATTRS: RefCell<Vec<u64>> = RefCell::new(Vec::new());
}
enum AttrError {
MultipleItem(Name),
UnknownMetaItem(Name),
MissingSince,
MissingFeature,
MultipleStabilityLevels,
UnsupportedLiteral
}
fn handle_errors(diag: &Handler, span: Span, error: AttrError) {
match error {
AttrError::MultipleItem(item) => span_err!(diag, span, E0538,
"multiple '{}' items", item),
AttrError::UnknownMetaItem(item) => span_err!(diag, span, E0541,
"unknown meta item '{}'", item),
AttrError::MissingSince => span_err!(diag, span, E0542, "missing 'since'"),
AttrError::MissingFeature => span_err!(diag, span, E0546, "missing 'feature'"),
AttrError::MultipleStabilityLevels => span_err!(diag, span, E0544,
"multiple stability levels"),
AttrError::UnsupportedLiteral => span_err!(diag, span, E0565, "unsupported literal"),
}
}
pub fn mark_used(attr: &Attribute) {
debug!("Marking {:?} as used.", attr);
let AttrId(id) = attr.id;
USED_ATTRS.with(|slot| {
let idx = (id / 64) as usize;
let shift = id % 64;
if slot.borrow().len() <= idx {
slot.borrow_mut().resize(idx + 1, 0);
}
slot.borrow_mut()[idx] |= 1 << shift;
});
}
pub fn is_used(attr: &Attribute) -> bool {
let AttrId(id) = attr.id;
USED_ATTRS.with(|slot| {
let idx = (id / 64) as usize;
let shift = id % 64;
slot.borrow().get(idx).map(|bits| bits & (1 << shift) != 0)
.unwrap_or(false)
})
}
pub fn mark_known(attr: &Attribute) {
debug!("Marking {:?} as known.", attr);
let AttrId(id) = attr.id;
KNOWN_ATTRS.with(|slot| {
let idx = (id / 64) as usize;
let shift = id % 64;
if slot.borrow().len() <= idx {
slot.borrow_mut().resize(idx + 1, 0);
}
slot.borrow_mut()[idx] |= 1 << shift;
});
}
pub fn is_known(attr: &Attribute) -> bool {
let AttrId(id) = attr.id;
KNOWN_ATTRS.with(|slot| {
let idx = (id / 64) as usize;
let shift = id % 64;
slot.borrow().get(idx).map(|bits| bits & (1 << shift) != 0)
.unwrap_or(false)
})
}
impl NestedMetaItem {
/// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
pub fn meta_item(&self) -> Option<&MetaItem> {
match self.node {
NestedMetaItemKind::MetaItem(ref item) => Some(&item),
_ => None
}
}
/// Returns the Lit if self is a NestedMetaItemKind::Literal.
pub fn literal(&self) -> Option<&Lit> {
match self.node {
NestedMetaItemKind::Literal(ref lit) => Some(&lit),
_ => None
}
}
/// Returns the Span for `self`.
pub fn span(&self) -> Span {
self.span
}
/// Returns true if this list item is a MetaItem with a name of `name`.
pub fn check_name(&self, name: &str) -> bool {
self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
}
/// Returns the name of the meta item, e.g. `foo` in `#[foo]`,
/// `#[foo="bar"]` and `#[foo(bar)]`, if self is a MetaItem
pub fn name(&self) -> Option<Name> {
self.meta_item().and_then(|meta_item| Some(meta_item.name()))
}
/// Gets the string value if self is a MetaItem and the MetaItem is a
/// MetaItemKind::NameValue variant containing a string, otherwise None.
pub fn value_str(&self) -> Option<Symbol> {
self.meta_item().and_then(|meta_item| meta_item.value_str())
}
/// Returns a name and single literal value tuple of the MetaItem.
pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
self.meta_item().and_then(
|meta_item| meta_item.meta_item_list().and_then(
|meta_item_list| {
if meta_item_list.len() == 1 {
let nested_item = &meta_item_list[0];
if nested_item.is_literal() {
Some((meta_item.name(), nested_item.literal().unwrap()))
} else {
None
}
}
else {
None
}}))
}
/// Returns a MetaItem if self is a MetaItem with Kind Word.
pub fn word(&self) -> Option<&MetaItem> {
self.meta_item().and_then(|meta_item| if meta_item.is_word() {
Some(meta_item)
} else {
None
})
}
/// Gets a list of inner meta items from a list MetaItem type.
pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
}
/// Returns `true` if the variant is MetaItem.
pub fn is_meta_item(&self) -> bool {
self.meta_item().is_some()
}
/// Returns `true` if the variant is Literal.
pub fn is_literal(&self) -> bool {
self.literal().is_some()
}
/// Returns `true` if self is a MetaItem and the meta item is a word.
pub fn is_word(&self) -> bool {
self.word().is_some()
}
/// Returns `true` if self is a MetaItem and the meta item is a ValueString.
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
/// Returns `true` if self is a MetaItem and the meta item is a list.
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
}
impl Attribute {
pub fn check_name(&self, name: &str) -> bool {
let matches = self.path == name;
if matches {
mark_used(self);
}
matches
}
pub fn name(&self) -> Option<Name> {
match self.path.segments.len() {
1 => Some(self.path.segments[0].identifier.name),
_ => None,
}
}
pub fn value_str(&self) -> Option<Symbol> {
self.meta().and_then(|meta| meta.value_str())
}
pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
match self.meta() {
Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
_ => None
}
}
pub fn is_word(&self) -> bool {
self.path.segments.len() == 1 && self.tokens.is_empty()
}
pub fn span(&self) -> Span {
self.span
}
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
/// Indicates if the attribute is a Value String.
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
}
impl MetaItem {
pub fn name(&self) -> Name {
self.name
}
pub fn value_str(&self) -> Option<Symbol> {
match self.node {
MetaItemKind::NameValue(ref v) => {
match v.node {
LitKind::Str(ref s, _) => Some((*s).clone()),
_ => None,
}
},
_ => None
}
}
pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
match self.node {
MetaItemKind::List(ref l) => Some(&l[..]),
_ => None
}
}
pub fn is_word(&self) -> bool {
match self.node {
MetaItemKind::Word => true,
_ => false,
}
}
pub fn span(&self) -> Span { self.span }
pub fn check_name(&self, name: &str) -> bool {
self.name() == name
}
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
}
impl Attribute {
/// Extract the MetaItem from inside this Attribute.
pub fn meta(&self) -> Option<MetaItem> {
let mut tokens = self.tokens.trees().peekable();
Some(MetaItem {
name: match self.path.segments.len() {
1 => self.path.segments[0].identifier.name,
_ => return None,
},
node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
if tokens.peek().is_some() {
return None;
}
node
} else {
return None;
},
span: self.span,
})
}
pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
{
let mut parser = Parser::new(sess, self.tokens.clone(), None, false);
let result = f(&mut parser)?;
if parser.token != token::Eof {
parser.unexpected()?;
}
Ok(result)
}
pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
{
if self.tokens.is_empty() {
return Ok(Vec::new());
}
self.parse(sess, |parser| {
parser.expect(&token::OpenDelim(token::Paren))?;
let mut list = Vec::new();
while !parser.eat(&token::CloseDelim(token::Paren)) {
list.push(f(parser)?);
if !parser.eat(&token::Comma) {
parser.expect(&token::CloseDelim(token::Paren))?;
break
}
}
Ok(list)
})
}
pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
if self.path.segments.len() > 1 {
sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
}
Ok(MetaItem {
name: self.path.segments.last().unwrap().identifier.name,
node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
span: self.span,
})
}
/// Convert self to a normal #[doc="foo"] comment, if it is a
/// comment like `///` or `/** */`. (Returns self unchanged for
/// non-sugared doc attributes.)
pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
F: FnOnce(&Attribute) -> T,
{
if self.is_sugared_doc {
let comment = self.value_str().unwrap();
let meta = mk_name_value_item_str(
Symbol::intern("doc"),
Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())));
if self.style == ast::AttrStyle::Outer {
f(&mk_attr_outer(self.span, self.id, meta))
} else {
f(&mk_attr_inner(self.span, self.id, meta))
}
} else {
f(self)
}
}
}
/* Constructors */
pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
}
pub fn mk_name_value_item(name: Name, value: ast::Lit) -> MetaItem {
mk_spanned_name_value_item(DUMMY_SP, name, value)
}
pub fn mk_list_item(name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
mk_spanned_list_item(DUMMY_SP, name, items)
}
pub fn mk_list_word_item(name: Name) -> ast::NestedMetaItem {
dummy_spanned(NestedMetaItemKind::MetaItem(mk_spanned_word_item(DUMMY_SP, name)))
}
pub fn mk_word_item(name: Name) -> MetaItem {
mk_spanned_word_item(DUMMY_SP, name)
}
pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
MetaItem { span: sp, name: name, node: MetaItemKind::NameValue(value) }
}
pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
MetaItem { span: sp, name: name, node: MetaItemKind::List(items) }
}
pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
MetaItem { span: sp, name: name, node: MetaItemKind::Word }
}
thread_local! { static NEXT_ATTR_ID: Cell<usize> = Cell::new(0) }
pub fn mk_attr_id() -> AttrId {
let id = NEXT_ATTR_ID.with(|slot| {
let r = slot.get();
slot.set(r + 1);
r
});
AttrId(id)
}
/// Returns an inner attribute with the given value.
pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
mk_spanned_attr_inner(span, id, item)
}
/// Returns an innter attribute with the given value and span.
pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
Attribute {
id: id,
style: ast::AttrStyle::Inner,
path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
tokens: item.node.tokens(item.span),
is_sugared_doc: false,
span: sp,
}
}
/// Returns an outer attribute with the given value.
pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
mk_spanned_attr_outer(span, id, item)
}
/// Returns an outer attribute with the given value and span.
pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
Attribute {
id: id,
style: ast::AttrStyle::Outer,
path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
tokens: item.node.tokens(item.span),
is_sugared_doc: false,
span: sp,
}
}
pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
let style = doc_comment_style(&text.as_str());
let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
Attribute {
id: id,
style: style,
path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
tokens: MetaItemKind::NameValue(lit).tokens(span),
is_sugared_doc: true,
span: span,
}
}
pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
items.iter().any(|item| {
item.check_name(name)
})
}
pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
attrs.iter().any(|item| {
item.check_name(name)
})
}
pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
attrs.iter()
.find(|at| at.check_name(name))
.and_then(|at| at.value_str())
}
/* Higher-level applications */
pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
first_attr_value_str_by_name(attrs, "crate_name")
}
/// Find the value of #[export_name=*] attribute and check its validity.
pub fn find_export_name_attr(diag: &Handler, attrs: &[Attribute]) -> Option<Symbol> {
attrs.iter().fold(None, |ia,attr| {
if attr.check_name("export_name") {
if let s@Some(_) = attr.value_str() {
s
} else {
struct_span_err!(diag, attr.span, E0558,
"export_name attribute has invalid format")
.span_label(attr.span,
&format!("did you mean #[export_name=\"*\"]?"))
.emit();
None
}
} else {
ia
}
})
}
pub fn contains_extern_indicator(diag: &Handler, attrs: &[Attribute]) -> bool {
contains_name(attrs, "no_mangle") ||
find_export_name_attr(diag, attrs).is_some()
}
#[derive(Copy, Clone, PartialEq)]
pub enum InlineAttr {
None,
Hint,
Always,
Never,
}
/// Determine what `#[inline]` attribute is present in `attrs`, if any.
pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
attrs.iter().fold(InlineAttr::None, |ia, attr| {
if attr.path != "inline" {
return ia;
}
let meta = match attr.meta() {
Some(meta) => meta.node,
None => return ia,
};
match meta {
MetaItemKind::Word => {
mark_used(attr);
InlineAttr::Hint
}
MetaItemKind::List(ref items) => {
mark_used(attr);
if items.len() != 1 {
diagnostic.map(|d|{ span_err!(d, attr.span, E0534, "expected one argument"); });
InlineAttr::None
} else if list_contains_name(&items[..], "always") {
InlineAttr::Always
} else if list_contains_name(&items[..], "never") {
InlineAttr::Never
} else {
diagnostic.map(|d| {
span_err!(d, items[0].span, E0535, "invalid argument");
});
InlineAttr::None
}
}
_ => ia,
}
})
}
/// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
pub fn requests_inline(attrs: &[Attribute]) -> bool {
match find_inline_attr(None, attrs) {
InlineAttr::Hint | InlineAttr::Always => true,
InlineAttr::None | InlineAttr::Never => false,
}
}
/// Tests if a cfg-pattern matches the cfg set
pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
match cfg.node {
ast::MetaItemKind::List(ref mis) => {
for mi in mis.iter() {
if !mi.is_meta_item() {
handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
return false;
}
}
// The unwraps below may look dangerous, but we've already asserted
// that they won't fail with the loop above.
match &*cfg.name.as_str() {
"any" => mis.iter().any(|mi| {
cfg_matches(mi.meta_item().unwrap(), sess, features)
}),
"all" => mis.iter().all(|mi| {
cfg_matches(mi.meta_item().unwrap(), sess, features)
}),
"not" => {
if mis.len() != 1 {
span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
return false;
}
!cfg_matches(mis[0].meta_item().unwrap(), sess, features)
},
p => {
span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
false
}
}
},
ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
gated_cfg.check_and_emit(sess, feats);
}
sess.config.contains(&(cfg.name(), cfg.value_str()))
}
}
}
/// Represents the #[stable], #[unstable] and #[rustc_deprecated] attributes.
#[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
pub struct Stability {
pub level: StabilityLevel,
pub feature: Symbol,
pub rustc_depr: Option<RustcDeprecation>,
}
/// The available stability levels.
#[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
pub enum StabilityLevel {
// Reason for the current stability level and the relevant rust-lang issue
Unstable { reason: Option<Symbol>, issue: u32 },
Stable { since: Symbol },
}
#[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
pub struct RustcDeprecation {
pub since: Symbol,
pub reason: Symbol,
}
#[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
pub struct Deprecation {
pub since: Option<Symbol>,
pub note: Option<Symbol>,
}
impl StabilityLevel {
pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
}
fn find_stability_generic<'a, I>(diagnostic: &Handler,
attrs_iter: I,
item_sp: Span)
-> Option<Stability>
where I: Iterator<Item = &'a Attribute>
{
let mut stab: Option<Stability> = None;
let mut rustc_depr: Option<RustcDeprecation> = None;
'outer: for attr in attrs_iter {
if attr.path != "rustc_deprecated" && attr.path != "unstable" && attr.path != "stable" {
continue // not a stability level
}
mark_used(attr);
let meta = attr.meta();
if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
let meta = meta.as_ref().unwrap();
let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
if item.is_some() {
handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
return false
}
if let Some(v) = meta.value_str() {
*item = Some(v);
true
} else {
span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
false
}
};
match &*meta.name.as_str() {
"rustc_deprecated" => {
if rustc_depr.is_some() {
span_err!(diagnostic, item_sp, E0540,
"multiple rustc_deprecated attributes");
break
}
let mut since = None;
let mut reason = None;
for meta in metas {
if let Some(mi) = meta.meta_item() {
match &*mi.name().as_str() {
"since" => if !get(mi, &mut since) { continue 'outer },
"reason" => if !get(mi, &mut reason) { continue 'outer },
_ => {
handle_errors(diagnostic, mi.span,
AttrError::UnknownMetaItem(mi.name()));
continue 'outer
}
}
} else {
handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
continue 'outer
}
}
match (since, reason) {
(Some(since), Some(reason)) => {
rustc_depr = Some(RustcDeprecation {
since: since,
reason: reason,
})
}
(None, _) => {
handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
continue
}
_ => {
span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
continue
}
}
}
"unstable" => {
if stab.is_some() {
handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
break
}
let mut feature = None;
let mut reason = None;
let mut issue = None;
for meta in metas {
if let Some(mi) = meta.meta_item() {
match &*mi.name().as_str() {
"feature" => if !get(mi, &mut feature) { continue 'outer },
"reason" => if !get(mi, &mut reason) { continue 'outer },
"issue" => if !get(mi, &mut issue) { continue 'outer },
_ => {
handle_errors(diagnostic, meta.span,
AttrError::UnknownMetaItem(mi.name()));
continue 'outer
}
}
} else {
handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
continue 'outer
}
}
match (feature, reason, issue) {
(Some(feature), reason, Some(issue)) => {
stab = Some(Stability {
level: Unstable {
reason: reason,
issue: {
if let Ok(issue) = issue.as_str().parse() {
issue
} else {
span_err!(diagnostic, attr.span(), E0545,
"incorrect 'issue'");
continue
}
}
},
feature: feature,
rustc_depr: None,
})
}
(None, _, _) => {
handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
continue
}
_ => {
span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
continue
}
}
}
"stable" => {
if stab.is_some() {
handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
break
}
let mut feature = None;
let mut since = None;
for meta in metas {
if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
match &*mi.name().as_str() {
"feature" => if !get(mi, &mut feature) { continue 'outer },
"since" => if !get(mi, &mut since) { continue 'outer },
_ => {
handle_errors(diagnostic, meta.span,
AttrError::UnknownMetaItem(mi.name()));
continue 'outer
}
}
} else {
handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
continue 'outer
}
}
match (feature, since) {
(Some(feature), Some(since)) => {
stab = Some(Stability {
level: Stable {
since: since,
},
feature: feature,
rustc_depr: None,
})
}
(None, _) => {
handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
continue
}
_ => {
handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
continue
}
}
}
_ => unreachable!()
}
} else {
span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
continue
}
}
// Merge the deprecation info into the stability info
if let Some(rustc_depr) = rustc_depr {
if let Some(ref mut stab) = stab {
stab.rustc_depr = Some(rustc_depr);
} else {
span_err!(diagnostic, item_sp, E0549,
"rustc_deprecated attribute must be paired with \
either stable or unstable attribute");
}
}
stab
}
fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
attrs_iter: I,
item_sp: Span)
-> Option<Deprecation>
where I: Iterator<Item = &'a Attribute>
{
let mut depr: Option<Deprecation> = None;
'outer: for attr in attrs_iter {
if attr.path != "deprecated" {
continue
}
mark_used(attr);
if depr.is_some() {
span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
break
}
depr = if let Some(metas) = attr.meta_item_list() {
let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
if item.is_some() {
handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
return false
}
if let Some(v) = meta.value_str() {
*item = Some(v);
true
} else {
span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
false
}
};
let mut since = None;
let mut note = None;
for meta in metas {
if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
match &*mi.name().as_str() {
"since" => if !get(mi, &mut since) { continue 'outer },
"note" => if !get(mi, &mut note) { continue 'outer },
_ => {
handle_errors(diagnostic, meta.span,
AttrError::UnknownMetaItem(mi.name()));
continue 'outer
}
}
} else {
handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
continue 'outer
}
}
Some(Deprecation {since: since, note: note})
} else {
Some(Deprecation{since: None, note: None})
}
}
depr
}
/// Find the first stability attribute. `None` if none exists.
pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
item_sp: Span) -> Option<Stability> {
find_stability_generic(diagnostic, attrs.iter(), item_sp)
}
/// Find the deprecation attribute. `None` if none exists.
pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
item_sp: Span) -> Option<Deprecation> {
find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
}
/// Parse #[repr(...)] forms.
///
/// Valid repr contents: any of the primitive integral type names (see
/// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
/// the same discriminant size that the corresponding C enum would or C
/// structure layout, and `packed` to remove padding.
pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
let mut acc = Vec::new();
if attr.path == "repr" {
if let Some(items) = attr.meta_item_list() {
mark_used(attr);
for item in items {
if !item.is_meta_item() {
handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
continue
}
let mut recognised = false;
if let Some(mi) = item.word() {
let word = &*mi.name().as_str();
let hint = match word {
// Can't use "extern" because it's not a lexical identifier.
"C" => Some(ReprExtern),
"packed" => Some(ReprPacked),
"simd" => Some(ReprSimd),
_ => match int_type_of_word(word) {
Some(ity) => Some(ReprInt(ity)),
None => {
None
}
}
};
if let Some(h) = hint {
recognised = true;
acc.push(h);
}
} else if let Some((name, value)) = item.name_value_literal() {
if name == "align" {
recognised = true;
let mut align_error = None;
if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
if align.is_power_of_two() {
// rustc::ty::layout::Align restricts align to <= 32768
if align <= 32768 {
acc.push(ReprAlign(align as u16));
} else {
align_error = Some("larger than 32768");
}
} else {
align_error = Some("not a power of two");
}
} else {
align_error = Some("not an unsuffixed integer");
}
if let Some(align_error) = align_error {
span_err!(diagnostic, item.span, E0589,
"invalid `repr(align)` attribute: {}", align_error);
}
}
}
if !recognised {
// Not a word we recognize
span_err!(diagnostic, item.span, E0552,
"unrecognized representation hint");
}
}
}
}
acc
}
fn int_type_of_word(s: &str) -> Option<IntType> {
match s {
"i8" => Some(SignedInt(ast::IntTy::I8)),
"u8" => Some(UnsignedInt(ast::UintTy::U8)),
"i16" => Some(SignedInt(ast::IntTy::I16)),
"u16" => Some(UnsignedInt(ast::UintTy::U16)),
"i32" => Some(SignedInt(ast::IntTy::I32)),
"u32" => Some(UnsignedInt(ast::UintTy::U32)),
"i64" => Some(SignedInt(ast::IntTy::I64)),
"u64" => Some(UnsignedInt(ast::UintTy::U64)),
"i128" => Some(SignedInt(ast::IntTy::I128)),
"u128" => Some(UnsignedInt(ast::UintTy::U128)),
"isize" => Some(SignedInt(ast::IntTy::Is)),
"usize" => Some(UnsignedInt(ast::UintTy::Us)),
_ => None
}
}
#[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
pub enum ReprAttr {
ReprInt(IntType),
ReprExtern,
ReprPacked,
ReprSimd,
ReprAlign(u16),
}
#[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
pub enum IntType {
SignedInt(ast::IntTy),
UnsignedInt(ast::UintTy)
}
impl IntType {
#[inline]
pub fn is_signed(self) -> bool {
match self {
SignedInt(..) => true,
UnsignedInt(..) => false
}
}
}
impl MetaItem {
fn tokens(&self) -> TokenStream {
let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
where I: Iterator<Item = TokenTree>,
{
let (mut span, name) = match tokens.next() {
Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match **nt {
token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
_ => return None,
},
_ => return None,
};
let node = match MetaItemKind::from_tokens(tokens) {
Some(node) => node,
_ => return None,
};
if let Some(last_span) = node.last_span() {
span.hi = last_span.hi;
}
Some(MetaItem { name: name, span: span, node: node })
}
}
impl MetaItemKind {
fn last_span(&self) -> Option<Span> {
match *self {
MetaItemKind::Word => None,
MetaItemKind::List(ref list) => list.last().map(NestedMetaItem::span),
MetaItemKind::NameValue(ref lit) => Some(lit.span),
}
}
pub fn tokens(&self, span: Span) -> TokenStream {
match *self {
MetaItemKind::Word => TokenStream::empty(),
MetaItemKind::NameValue(ref lit) => {
TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
}
MetaItemKind::List(ref list) => {
let mut tokens = Vec::new();
for (i, item) in list.iter().enumerate() {
if i > 0 {
tokens.push(TokenTree::Token(span, Token::Comma).into());
}
tokens.push(item.node.tokens());
}
TokenTree::Delimited(span, Delimited {
delim: token::Paren,
tts: TokenStream::concat(tokens).into(),
}).into()
}
}
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
where I: Iterator<Item = TokenTree>,
{
let delimited = match tokens.peek().cloned() {
Some(TokenTree::Token(_, token::Eq)) => {
tokens.next();
return if let Some(TokenTree::Token(span, token)) = tokens.next() {
LitKind::from_token(token)
.map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
} else {
None
};
}
Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
tokens.next();
delimited.stream()
}
_ => return Some(MetaItemKind::Word),
};
let mut tokens = delimited.into_trees().peekable();
let mut result = Vec::new();
while let Some(..) = tokens.peek() {
match NestedMetaItemKind::from_tokens(&mut tokens) {
Some(item) => result.push(Spanned { span: item.span(), node: item }),
None => return None,
}
match tokens.next() {
None | Some(TokenTree::Token(_, Token::Comma)) => {}
_ => return None,
}
}
Some(MetaItemKind::List(result))
}
}
impl NestedMetaItemKind {
fn span(&self) -> Span {
match *self {
NestedMetaItemKind::MetaItem(ref item) => item.span,
NestedMetaItemKind::Literal(ref lit) => lit.span,
}
}
fn tokens(&self) -> TokenStream {
match *self {
NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
}
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
where I: Iterator<Item = TokenTree>,
{
if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
if let Some(node) = LitKind::from_token(token) {
tokens.next();
return Some(NestedMetaItemKind::Literal(Spanned { node: node, span: span }));
}
}
MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
}
}
impl Lit {
fn tokens(&self) -> TokenStream {
TokenTree::Token(self.span, self.node.token()).into()
}
}
impl LitKind {
fn token(&self) -> Token {
use std::ascii;
match *self {
LitKind::Str(string, ast::StrStyle::Cooked) => {
let mut escaped = String::new();
for ch in string.as_str().chars() {
escaped.extend(ch.escape_unicode());
}
Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
}
LitKind::Str(string, ast::StrStyle::Raw(n)) => {
Token::Literal(token::Lit::StrRaw(string, n), None)
}
LitKind::ByteStr(ref bytes) => {
let string = bytes.iter().cloned().flat_map(ascii::escape_default)
.map(Into::<char>::into).collect::<String>();
Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
}
LitKind::Byte(byte) => {
let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
}
LitKind::Char(ch) => {
let string: String = ch.escape_default().map(Into::<char>::into).collect();
Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
}
LitKind::Int(n, ty) => {
let suffix = match ty {
ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
ast::LitIntType::Unsuffixed => None,
};
Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
}
LitKind::Float(symbol, ty) => {
Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
}
LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(match value {
true => "true",
false => "false",
}))),
}
}
fn from_token(token: Token) -> Option<LitKind> {
match token {
Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
Token::Interpolated(ref nt) => match **nt {
token::NtExpr(ref v) => match v.node {
ExprKind::Lit(ref lit) => Some(lit.node.clone()),
_ => None,
},
_ => None,
},
Token::Literal(lit, suf) => {
let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
if suffix_illegal && suf.is_some() {
return None;
}
result
}
_ => None,
}
}
}
pub trait HasAttrs: Sized {
fn attrs(&self) -> &[ast::Attribute];
fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
}
impl<T: HasAttrs> HasAttrs for Spanned<T> {
fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
Spanned { node: self.node.map_attrs(f), span: self.span }
}
}
impl HasAttrs for Vec<Attribute> {
fn attrs(&self) -> &[Attribute] {
&self
}
fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
f(self)
}
}
impl HasAttrs for ThinVec<Attribute> {
fn attrs(&self) -> &[Attribute] {
&self
}
fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
f(self.into()).into()
}
}
impl<T: HasAttrs + 'static> HasAttrs for P<T> {
fn attrs(&self) -> &[Attribute] {
(**self).attrs()
}
fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
self.map(|t| t.map_attrs(f))
}
}
impl HasAttrs for StmtKind {
fn attrs(&self) -> &[Attribute] {
match *self {
StmtKind::Local(ref local) => local.attrs(),
StmtKind::Item(..) => &[],
StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
StmtKind::Mac(ref mac) => {
let (_, _, ref attrs) = **mac;
attrs.attrs()
}
}
}
fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
match self {
StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
StmtKind::Item(..) => self,
StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
(mac, style, attrs.map_attrs(f))
})),
}
}
}
impl HasAttrs for Stmt {
fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
}
}
macro_rules! derive_has_attrs {
($($ty:path),*) => { $(
impl HasAttrs for $ty {
fn attrs(&self) -> &[Attribute] {
&self.attrs
}
fn map_attrs<F>(mut self, f: F) -> Self
where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
{
self.attrs = self.attrs.map_attrs(f);
self
}
}
)* }
}
derive_has_attrs! {
Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
ast::Field, ast::FieldPat, ast::Variant_
}