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feature gate cfg(target_feature).

Browse source 
This is theoretically a breaking change, but GitHub search turns up no
uses of it, and most non-built-in cfg's are passed via cargo features,
which look like `feature = "..."`, and hence can't overlap.
This commit is contained in:
Huon Wilson 2015-07-13 17:10:44 -07:00
parent c66554cab3
commit e364f0eb5a
11 changed files with 150 additions and 28 deletions
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19
src/librustc_driver/driver.rs
View file

@ -406,8 +406,10 @@ pub fn phase_2_configure_and_expand(sess: &Session,
//
// baz! should not use this definition unless foo is enabled.
krate = time(time_passes, "configuration 1", move ||
syntax::config::strip_unconfigured_items(sess.diagnostic(), krate));
let mut feature_gated_cfgs = vec![];
krate = time(time_passes, "configuration 1", ||
syntax::config::strip_unconfigured_items(sess.diagnostic(), krate,
&mut feature_gated_cfgs));
*sess.crate_types.borrow_mut() =
collect_crate_types(sess, &krate.attrs);
@ -511,6 +513,7 @@ pub fn phase_2_configure_and_expand(sess: &Session,
cfg,
macros,
syntax_exts,
&mut feature_gated_cfgs,
krate);
if cfg!(windows) {
env::set_var("PATH", &_old_path);
@ -536,7 +539,17 @@ pub fn phase_2_configure_and_expand(sess: &Session,
// strip again, in case expansion added anything with a #[cfg].
krate = time(time_passes, "configuration 2", ||
syntax::config::strip_unconfigured_items(sess.diagnostic(), krate));
syntax::config::strip_unconfigured_items(sess.diagnostic(), krate,
&mut feature_gated_cfgs));
time(time_passes, "gated configuration checking", || {
let features = sess.features.borrow();
feature_gated_cfgs.sort();
feature_gated_cfgs.dedup();
for cfg in &feature_gated_cfgs {
cfg.check_and_emit(sess.diagnostic(), &features);
}
});
krate = time(time_passes, "maybe building test harness", ||
syntax::test::modify_for_testing(&sess.parse_sess,

15
src/libsyntax/attr.rs
View file

@ -19,6 +19,7 @@ use ast::{AttrId, Attribute, Attribute_, MetaItem, MetaWord, MetaNameValue, Meta
use codemap::{Span, Spanned, spanned, dummy_spanned};
use codemap::BytePos;
use diagnostic::SpanHandler;
use feature_gate::GatedCfg;
use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
use parse::token::{InternedString, intern_and_get_ident};
use parse::token;
@ -357,24 +358,28 @@ pub fn requests_inline(attrs: &[Attribute]) -> bool {
}
/// Tests if a cfg-pattern matches the cfg set
pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem) -> bool {
pub fn cfg_matches(diagnostic: &SpanHandler, cfgs: &[P<MetaItem>], cfg: &ast::MetaItem,
feature_gated_cfgs: &mut Vec<GatedCfg>) -> bool {
match cfg.node {
ast::MetaList(ref pred, ref mis) if &pred[..] == "any" =>
mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
mis.iter().any(|mi| cfg_matches(diagnostic, cfgs, &**mi, feature_gated_cfgs)),
ast::MetaList(ref pred, ref mis) if &pred[..] == "all" =>
mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi)),
mis.iter().all(|mi| cfg_matches(diagnostic, cfgs, &**mi, feature_gated_cfgs)),
ast::MetaList(ref pred, ref mis) if &pred[..] == "not" => {
if mis.len() != 1 {
diagnostic.span_err(cfg.span, "expected 1 cfg-pattern");
return false;
}
!cfg_matches(diagnostic, cfgs, &*mis[0])
!cfg_matches(diagnostic, cfgs, &*mis[0], feature_gated_cfgs)
}
ast::MetaList(ref pred, _) => {
diagnostic.span_err(cfg.span, &format!("invalid predicate `{}`", pred));
false
},
ast::MetaWord(_) | ast::MetaNameValue(..) => contains(cfgs, cfg),
ast::MetaWord(_) | ast::MetaNameValue(..) => {
feature_gated_cfgs.extend(GatedCfg::gate(cfg));
contains(cfgs, cfg)
}
}
}

28
src/libsyntax/config.rs
View file

@ -10,6 +10,7 @@
use attr::AttrMetaMethods;
use diagnostic::SpanHandler;
use feature_gate::GatedCfg;
use fold::Folder;
use {ast, fold, attr};
use codemap::{Spanned, respan};
@ -25,10 +26,13 @@ struct Context<F> where F: FnMut(&[ast::Attribute]) -> bool {
// Support conditional compilation by transforming the AST, stripping out
// any items that do not belong in the current configuration
pub fn strip_unconfigured_items(diagnostic: &SpanHandler, krate: ast::Crate) -> ast::Crate {
let krate = process_cfg_attr(diagnostic, krate);
pub fn strip_unconfigured_items(diagnostic: &SpanHandler, krate: ast::Crate,
feature_gated_cfgs: &mut Vec<GatedCfg>)
-> ast::Crate
{
let krate = process_cfg_attr(diagnostic, krate, feature_gated_cfgs);
let config = krate.config.clone();
strip_items(krate, |attrs| in_cfg(diagnostic, &config, attrs))
strip_items(krate, |attrs| in_cfg(diagnostic, &config, attrs, feature_gated_cfgs))
}
impl<F> fold::Folder for Context<F> where F: FnMut(&[ast::Attribute]) -> bool {
@ -248,7 +252,8 @@ fn foreign_item_in_cfg<F>(cx: &mut Context<F>, item: &ast::ForeignItem) -> bool
// Determine if an item should be translated in the current crate
// configuration based on the item's attributes
fn in_cfg(diagnostic: &SpanHandler, cfg: &[P<ast::MetaItem>], attrs: &[ast::Attribute]) -> bool {
fn in_cfg(diagnostic: &SpanHandler, cfg: &[P<ast::MetaItem>], attrs: &[ast::Attribute],
feature_gated_cfgs: &mut Vec<GatedCfg>) -> bool {
attrs.iter().all(|attr| {
let mis = match attr.node.value.node {
ast::MetaList(_, ref mis) if attr.check_name("cfg") => mis,
@ -260,25 +265,29 @@ fn in_cfg(diagnostic: &SpanHandler, cfg: &[P<ast::MetaItem>], attrs: &[ast::Attr
return true;
}
attr::cfg_matches(diagnostic, cfg, &*mis[0])
attr::cfg_matches(diagnostic, cfg, &*mis[0],
feature_gated_cfgs)
})
}
struct CfgAttrFolder<'a> {
struct CfgAttrFolder<'a, 'b> {
diag: &'a SpanHandler,
config: ast::CrateConfig,
feature_gated_cfgs: &'b mut Vec<GatedCfg>
}
// Process `#[cfg_attr]`.
fn process_cfg_attr(diagnostic: &SpanHandler, krate: ast::Crate) -> ast::Crate {
fn process_cfg_attr(diagnostic: &SpanHandler, krate: ast::Crate,
feature_gated_cfgs: &mut Vec<GatedCfg>) -> ast::Crate {
let mut fld = CfgAttrFolder {
diag: diagnostic,
config: krate.config.clone(),
feature_gated_cfgs: feature_gated_cfgs,
};
fld.fold_crate(krate)
}
impl<'a> fold::Folder for CfgAttrFolder<'a> {
impl<'a,'b> fold::Folder for CfgAttrFolder<'a,'b> {
fn fold_attribute(&mut self, attr: ast::Attribute) -> Option<ast::Attribute> {
if !attr.check_name("cfg_attr") {
return fold::noop_fold_attribute(attr, self);
@ -299,7 +308,8 @@ impl<'a> fold::Folder for CfgAttrFolder<'a> {
}
};
if attr::cfg_matches(self.diag, &self.config[..], &cfg) {
if attr::cfg_matches(self.diag, &self.config[..], &cfg,
self.feature_gated_cfgs) {
Some(respan(mi.span, ast::Attribute_ {
id: attr::mk_attr_id(),
style: attr.node.style,

6
src/libsyntax/ext/base.rs
View file

@ -17,6 +17,7 @@ use codemap::{CodeMap, Span, ExpnId, ExpnInfo, NO_EXPANSION, CompilerExpansion};
use ext;
use ext::expand;
use ext::tt::macro_rules;
use feature_gate::GatedCfg;
use parse;
use parse::parser;
use parse::token;
@ -632,6 +633,7 @@ pub struct ExtCtxt<'a> {
pub backtrace: ExpnId,
pub ecfg: expand::ExpansionConfig<'a>,
pub crate_root: Option<&'static str>,
pub feature_gated_cfgs: &'a mut Vec<GatedCfg>,
pub mod_path: Vec<ast::Ident> ,
pub exported_macros: Vec<ast::MacroDef>,
@ -642,7 +644,8 @@ pub struct ExtCtxt<'a> {
impl<'a> ExtCtxt<'a> {
pub fn new(parse_sess: &'a parse::ParseSess, cfg: ast::CrateConfig,
ecfg: expand::ExpansionConfig<'a>) -> ExtCtxt<'a> {
ecfg: expand::ExpansionConfig<'a>,
feature_gated_cfgs: &'a mut Vec<GatedCfg>) -> ExtCtxt<'a> {
let env = initial_syntax_expander_table(&ecfg);
ExtCtxt {
parse_sess: parse_sess,
@ -651,6 +654,7 @@ impl<'a> ExtCtxt<'a> {
mod_path: Vec::new(),
ecfg: ecfg,
crate_root: None,
feature_gated_cfgs: feature_gated_cfgs,
exported_macros: Vec::new(),
syntax_env: env,
recursion_count: 0,

3
src/libsyntax/ext/cfg.rs
View file

@ -34,6 +34,7 @@ pub fn expand_cfg<'cx>(cx: &mut ExtCtxt,
return DummyResult::expr(sp);
}
let matches_cfg = attr::cfg_matches(&cx.parse_sess.span_diagnostic, &cx.cfg, &*cfg);
let matches_cfg = attr::cfg_matches(&cx.parse_sess.span_diagnostic, &cx.cfg, &*cfg,
cx.feature_gated_cfgs);
MacEager::expr(cx.expr_bool(sp, matches_cfg))
}

14
src/libsyntax/ext/expand.rs
View file

@ -21,7 +21,7 @@ use attr::AttrMetaMethods;
use codemap;
use codemap::{Span, Spanned, ExpnInfo, NameAndSpan, MacroBang, MacroAttribute, CompilerExpansion};
use ext::base::*;
use feature_gate::{self, Features};
use feature_gate::{self, Features, GatedCfg};
use fold;
use fold::*;
use parse;
@ -1687,8 +1687,10 @@ pub fn expand_crate<'feat>(parse_sess: &parse::ParseSess,
// these are the macros being imported to this crate:
imported_macros: Vec<ast::MacroDef>,
user_exts: Vec<NamedSyntaxExtension>,
feature_gated_cfgs: &mut Vec<GatedCfg>,
c: Crate) -> Crate {
let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg);
let mut cx = ExtCtxt::new(parse_sess, c.config.clone(), cfg,
feature_gated_cfgs);
if std_inject::no_core(&c) {
cx.crate_root = None;
} else if std_inject::no_std(&c) {
@ -1878,7 +1880,7 @@ mod tests {
src,
Vec::new(), &sess);
// should fail:
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
expand_crate(&sess,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast);
}
// make sure that macros can't escape modules
@ -1891,7 +1893,7 @@ mod tests {
"<test>".to_string(),
src,
Vec::new(), &sess);
expand_crate(&sess,test_ecfg(),vec!(),vec!(),crate_ast);
expand_crate(&sess,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast);
}
// macro_use modules should allow macros to escape
@ -1903,14 +1905,14 @@ mod tests {
"<test>".to_string(),
src,
Vec::new(), &sess);
expand_crate(&sess, test_ecfg(), vec!(), vec!(), crate_ast);
expand_crate(&sess, test_ecfg(), vec!(), vec!(), &mut vec![], crate_ast);
}
fn expand_crate_str(crate_str: String) -> ast::Crate {
let ps = parse::ParseSess::new();
let crate_ast = panictry!(string_to_parser(&ps, crate_str).parse_crate_mod());
// the cfg argument actually does matter, here...
expand_crate(&ps,test_ecfg(),vec!(),vec!(),crate_ast)
expand_crate(&ps,test_ecfg(),vec!(),vec!(), &mut vec![], crate_ast)
}
// find the pat_ident paths in a crate

60
src/libsyntax/feature_gate.rs
View file

@ -37,6 +37,7 @@ use visit::Visitor;
use parse::token::{self, InternedString};
use std::ascii::AsciiExt;
use std::cmp;
// If you change this list without updating src/doc/reference.md, @cmr will be sad
// Don't ever remove anything from this list; set them to 'Removed'.
@ -180,6 +181,9 @@ const KNOWN_FEATURES: &'static [(&'static str, &'static str, Status)] = &[
// allow `repr(simd)`, and importing the various simd intrinsics
("simd_basics", "1.3.0", Active),
// Allows cfg(target_feature = "...").
("cfg_target_feature", "1.3.0", Active),
];
// (changing above list without updating src/doc/reference.md makes @cmr sad)
@ -327,6 +331,59 @@ pub const KNOWN_ATTRIBUTES: &'static [(&'static str, AttributeType)] = &[
("recursion_limit", CrateLevel),
];
macro_rules! cfg_fn {
(|$x: ident| $e: expr) => {{
fn f($x: &Features) -> bool {
$e
}
f as fn(&Features) -> bool
}}
}
// cfg(...)'s that are feature gated
const GATED_CFGS: &'static [(&'static str, &'static str, fn(&Features) -> bool)] = &[
// (name in cfg, feature, function to check if the feature is enabled)
("target_feature", "cfg_target_feature", cfg_fn!(|x| x.cfg_target_feature)),
];
#[derive(Debug, Eq, PartialEq)]
pub struct GatedCfg {
span: Span,
index: usize,
}
impl Ord for GatedCfg {
fn cmp(&self, other: &GatedCfg) -> cmp::Ordering {
(self.span.lo.0, self.span.hi.0, self.index)
.cmp(&(other.span.lo.0, other.span.hi.0, other.index))
}
}
impl PartialOrd for GatedCfg {
fn partial_cmp(&self, other: &GatedCfg) -> Option<cmp::Ordering> {
Some(self.cmp(other))
}
}
impl GatedCfg {
pub fn gate(cfg: &ast::MetaItem) -> Option<GatedCfg> {
let name = cfg.name();
GATED_CFGS.iter()
.position(|info| info.0 == name)
.map(|idx| {
GatedCfg {
span: cfg.span,
index: idx
}
})
}
pub fn check_and_emit(&self, diagnostic: &SpanHandler, features: &Features) {
let (cfg, feature, has_feature) = GATED_CFGS[self.index];
if !has_feature(features) {
let explain = format!("`cfg({})` is experimental and subject to change", cfg);
emit_feature_err(diagnostic, feature, self.span, &explain);
}
}
}
#[derive(PartialEq, Copy, Clone, Debug)]
pub enum AttributeType {
/// Normal, builtin attribute that is consumed
@ -373,6 +430,7 @@ pub struct Features {
pub static_recursion: bool,
pub default_type_parameter_fallback: bool,
pub type_macros: bool,
pub cfg_target_feature: bool,
}
impl Features {
@ -401,6 +459,7 @@ impl Features {
static_recursion: false,
default_type_parameter_fallback: false,
type_macros: false,
cfg_target_feature: false,
}
}
}
@ -920,6 +979,7 @@ fn check_crate_inner<F>(cm: &CodeMap, span_handler: &SpanHandler,
static_recursion: cx.has_feature("static_recursion"),
default_type_parameter_fallback: cx.has_feature("default_type_parameter_fallback"),
type_macros: cx.has_feature("type_macros"),
cfg_target_feature: cx.has_feature("cfg_target_feature"),
}
}

4
src/libsyntax/test.rs
View file

@ -246,11 +246,13 @@ fn generate_test_harness(sess: &ParseSess,
krate: ast::Crate,
cfg: &ast::CrateConfig,
sd: &diagnostic::SpanHandler) -> ast::Crate {
let mut feature_gated_cfgs = vec![];
let mut cx: TestCtxt = TestCtxt {
sess: sess,
span_diagnostic: sd,
ext_cx: ExtCtxt::new(sess, cfg.clone(),
ExpansionConfig::default("test".to_string())),
ExpansionConfig::default("test".to_string()),
&mut feature_gated_cfgs),
path: Vec::new(),
testfns: Vec::new(),
reexport_test_harness_main: reexport_test_harness_main,

21
src/test/compile-fail/feature-gate-cfg-target-feature.rs Normal file
View file

@ -0,0 +1,21 @@
// Copyright 2015 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.
#[cfg(target_feature = "x")] //~ ERROR `cfg(target_feature)` is experimental
#[cfg_attr(target_feature = "x", x)] //~ ERROR `cfg(target_feature)` is experimental
struct Foo(u64, u64);
#[cfg(not(any(all(target_feature = "x"))))] //~ ERROR `cfg(target_feature)` is experimental
fn foo() {}
fn main() {
cfg!(target_feature = "x");
//~^ ERROR `cfg(target_feature)` is experimental and subject to change
}

4
src/test/run-fail-fulldeps/qquote.rs
View file

@ -23,9 +23,11 @@ use syntax::print::pprust;
fn main() {
let ps = syntax::parse::ParseSess::new();
let mut feature_gated_cfgs = vec![];
let mut cx = syntax::ext::base::ExtCtxt::new(
&ps, vec![],
syntax::ext::expand::ExpansionConfig::default("qquote".to_string()));
syntax::ext::expand::ExpansionConfig::default("qquote".to_string()),
&mut feature_gated_cfgs);
cx.bt_push(syntax::codemap::ExpnInfo {
call_site: DUMMY_SP,
callee: syntax::codemap::NameAndSpan {

4
src/test/run-pass-fulldeps/qquote.rs
View file

@ -19,9 +19,11 @@ use syntax::print::pprust::*;
fn main() {
let ps = syntax::parse::ParseSess::new();
let mut feature_gated_cfgs = vec![];
let mut cx = syntax::ext::base::ExtCtxt::new(
&ps, vec![],
syntax::ext::expand::ExpansionConfig::default("qquote".to_string()));
syntax::ext::expand::ExpansionConfig::default("qquote".to_string()),
&mut feature_gated_cfgs);
cx.bt_push(syntax::codemap::ExpnInfo {
call_site: DUMMY_SP,
callee: syntax::codemap::NameAndSpan {