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Turn the duplicate feature lint into an error

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This commit is contained in:
varkor 2018-07-23 17:34:04 +01:00
parent c81b95f305
commit 47619c0dc7
6 changed files with 46 additions and 48 deletions
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13
src/librustc/diagnostics.rs
View file

@ -1918,6 +1918,19 @@ fn foo<'a>(x: &'a i32, y: &i32) -> &'a i32 {
```
"##,
E0636: r##"
A `#![feature]` attribute was declared multiple times.
Erroneous code example:
```compile_fail,E0636
#![allow(stable_features)]
#![feature(rust1)]
#![feature(rust1)] // error: the feature `rust1` has already been declared
```
"##,
E0644: r##"
A closure or generator was constructed that references its own type.

7
src/librustc/lint/builtin.rs
View file

@ -111,12 +111,6 @@ declare_lint! {
"unknown features found in crate-level #[feature] directives"
}
declare_lint! {
pub DUPLICATE_FEATURES,
Deny,
"duplicate features found in crate-level #[feature] directives"
}
declare_lint! {
pub STABLE_FEATURES,
Warn,
@ -375,7 +369,6 @@ impl LintPass for HardwiredLints {
WARNINGS,
UNUSED_FEATURES,
UNKNOWN_FEATURES,
DUPLICATE_FEATURES,
STABLE_FEATURES,
UNKNOWN_CRATE_TYPES,
TRIVIAL_CASTS,

49
src/librustc/middle/stability.rs
View file

@ -18,7 +18,7 @@ use hir::def::Def;
use hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefId, LOCAL_CRATE};
use ty::{self, TyCtxt};
use middle::privacy::AccessLevels;
use session::DiagnosticMessageId;
use session::{DiagnosticMessageId, Session};
use syntax::symbol::Symbol;
use syntax_pos::{Span, MultiSpan};
use syntax::ast;
@ -816,20 +816,14 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
let declared_lang_features = &tcx.features().declared_lang_features;
let mut lang_features = FxHashSet();
for &(ref feature, span, since) in declared_lang_features {
for &(feature, span, since) in declared_lang_features {
if let Some(since) = since {
// Warn if the user has enabled an already-stable lang feature.
tcx.lint_node(lint::builtin::STABLE_FEATURES,
ast::CRATE_NODE_ID,
span,
&format_stable_since_msg(*feature, since));
unnecessary_stable_feature_lint(tcx, span, feature, since);
}
if lang_features.contains(&feature) {
// Warn if the user enables a lang feature multiple times.
tcx.lint_node(lint::builtin::DUPLICATE_FEATURES,
ast::CRATE_NODE_ID,
span,
&format!("duplicate `{}` feature attribute", feature));
duplicate_feature_err(tcx.sess, span, feature);
}
lang_features.insert(feature);
}
@ -837,12 +831,9 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
let declared_lib_features = &tcx.features().declared_lib_features;
let mut remaining_lib_features = FxHashMap();
for (feature, span) in declared_lib_features {
// Warn if the user enables a lib feature multiple times.
if remaining_lib_features.contains_key(&feature) {
tcx.lint_node(lint::builtin::DUPLICATE_FEATURES,
ast::CRATE_NODE_ID,
*span,
&format!("duplicate `{}` feature attribute", feature));
// Warn if the user enables a lib feature multiple times.
duplicate_feature_err(tcx.sess, *span, *feature);
}
remaining_lib_features.insert(feature, span.clone());
}
@ -851,16 +842,12 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
remaining_lib_features.remove(&Symbol::intern("libc"));
for (feature, stable) in tcx.lib_features().iter() {
// Warn if the user has enabled an already-stable lib feature.
if let Some(since) = stable {
if let Some(span) = remaining_lib_features.get(&feature) {
tcx.lint_node(lint::builtin::STABLE_FEATURES,
ast::CRATE_NODE_ID,
*span,
&format_stable_since_msg(feature, since));
// Warn if the user has enabled an already-stable lib feature.
unnecessary_stable_feature_lint(tcx, *span, feature, since);
}
}
remaining_lib_features.remove(&feature);
}
@ -875,8 +862,20 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
// don't lint about unused features. We should reenable this one day!
}
fn format_stable_since_msg(feature: Symbol, since: Symbol) -> String {
// "this feature has been stable since {}. Attribute no longer needed"
format!("the feature `{}` has been stable since {} and no longer requires \
an attribute to enable", feature, since)
fn unnecessary_stable_feature_lint<'a, 'tcx>(
tcx: TyCtxt<'a, 'tcx, 'tcx>,
span: Span,
feature: Symbol,
since: Symbol
) {
tcx.lint_node(lint::builtin::STABLE_FEATURES,
ast::CRATE_NODE_ID,
span,
&format!("the feature `{}` has been stable since {} and no longer requires \
an attribute to enable", feature, since));
}
fn duplicate_feature_err(sess: &Session, span: Span, feature: Symbol) {
struct_span_err!(sess, span, E0636, "the feature `{}` has already been declared", feature)
.emit();
}

1
src/librustc_lint/lib.rs
View file

@ -189,7 +189,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
UNUSED_EXTERN_CRATES,
UNUSED_FEATURES,
UNKNOWN_FEATURES,
DUPLICATE_FEATURES,
UNUSED_LABELS,
UNUSED_PARENS);

5
src/test/ui/feature-gate/duplicate-features.rs
View file

@ -9,12 +9,11 @@
// except according to those terms.
#![allow(stable_features)]
#![deny(duplicate_features)]
#![feature(rust1)]
#![feature(rust1)] //~ ERROR duplicate `rust1` feature attribute
#![feature(rust1)] //~ ERROR the feature `rust1` has already been declared
#![feature(if_let)]
#![feature(if_let)] //~ ERROR duplicate `if_let` feature attribute
#![feature(if_let)] //~ ERROR the feature `if_let` has already been declared
fn main() {}

19
src/test/ui/feature-gate/duplicate-features.stderr
View file

@ -1,20 +1,15 @@
error: duplicate `if_let` feature attribute
--> $DIR/duplicate-features.rs:18:12
error[E0636]: the feature `if_let` has already been declared
--> $DIR/duplicate-features.rs:17:12
|
LL | #![feature(if_let)] //~ ERROR duplicate `if_let` feature attribute
LL | #![feature(if_let)] //~ ERROR the feature `if_let` has already been declared
| ^^^^^^
|
note: lint level defined here
--> $DIR/duplicate-features.rs:12:9
|
LL | #![deny(duplicate_features)]
| ^^^^^^^^^^^^^^^^^^
error: duplicate `rust1` feature attribute
--> $DIR/duplicate-features.rs:15:12
error[E0636]: the feature `rust1` has already been declared
--> $DIR/duplicate-features.rs:14:12
|
LL | #![feature(rust1)] //~ ERROR duplicate `rust1` feature attribute
LL | #![feature(rust1)] //~ ERROR the feature `rust1` has already been declared
| ^^^^^
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0636`.