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Support "soft" feature-gating using a lint

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Use it for feature-gating `#[bench]`
This commit is contained in:
Vadim Petrochenkov 2019-09-01 14:54:57 +03:00
parent ef54f57c5b
commit f7434aef26
9 changed files with 58 additions and 27 deletions
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3
src/librustc/ich/impls_syntax.rs
View file

@ -115,9 +115,10 @@ for ::syntax::attr::StabilityLevel {
hasher: &mut StableHasher<W>) {
mem::discriminant(self).hash_stable(hcx, hasher);
match *self {
::syntax::attr::StabilityLevel::Unstable { ref reason, ref issue } => {
::syntax::attr::StabilityLevel::Unstable { ref reason, ref issue, ref is_soft } => {
reason.hash_stable(hcx, hasher);
issue.hash_stable(hcx, hasher);
is_soft.hash_stable(hcx, hasher);
}
::syntax::attr::StabilityLevel::Stable { ref since } => {
since.hash_stable(hcx, hasher);

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

@ -395,6 +395,12 @@ declare_lint! {
"reservation of a two-phased borrow conflicts with other shared borrows"
}
declare_lint! {
pub SOFT_UNSTABLE,
Deny,
"a feature gate that doesn't break dependent crates"
}
declare_lint_pass! {
/// Does nothing as a lint pass, but registers some `Lint`s
/// that are used by other parts of the compiler.
@ -460,6 +466,7 @@ declare_lint_pass! {
NESTED_IMPL_TRAIT,
MUTABLE_BORROW_RESERVATION_CONFLICT,
INDIRECT_STRUCTURAL_MATCH,
SOFT_UNSTABLE,
]
}

22
src/librustc/middle/stability.rs
View file

@ -438,6 +438,7 @@ impl<'tcx> Index<'tcx> {
level: attr::StabilityLevel::Unstable {
reason: Some(Symbol::intern(reason)),
issue: 27812,
is_soft: false,
},
feature: sym::rustc_private,
rustc_depr: None,
@ -480,7 +481,7 @@ pub fn provide(providers: &mut Providers<'_>) {
}
pub fn report_unstable(
sess: &Session, feature: Symbol, reason: Option<Symbol>, issue: u32, span: Span
sess: &Session, feature: Symbol, reason: Option<Symbol>, issue: u32, is_soft: bool, span: Span
) {
let msg = match reason {
Some(r) => format!("use of unstable library feature '{}': {}", feature, r),
@ -505,7 +506,13 @@ pub fn report_unstable(
let error_id = (DiagnosticMessageId::StabilityId(issue), span_key, msg.clone());
let fresh = sess.one_time_diagnostics.borrow_mut().insert(error_id);
if fresh {
emit_feature_err(&sess.parse_sess, feature, span, GateIssue::Library(Some(issue)), &msg);
if is_soft {
sess.buffer_lint(lint::builtin::SOFT_UNSTABLE, CRATE_NODE_ID, span, &msg);
} else {
emit_feature_err(
&sess.parse_sess, feature, span, GateIssue::Library(Some(issue)), &msg
);
}
}
}
@ -621,6 +628,7 @@ pub enum EvalResult {
feature: Symbol,
reason: Option<Symbol>,
issue: u32,
is_soft: bool,
},
/// The item does not have the `#[stable]` or `#[unstable]` marker assigned.
Unmarked,
@ -720,7 +728,9 @@ impl<'tcx> TyCtxt<'tcx> {
}
match stability {
Some(&Stability { level: attr::Unstable { reason, issue }, feature, .. }) => {
Some(&Stability {
level: attr::Unstable { reason, issue, is_soft }, feature, ..
}) => {
if span.allows_unstable(feature) {
debug!("stability: skipping span={:?} since it is internal", span);
return EvalResult::Allow;
@ -744,7 +754,7 @@ impl<'tcx> TyCtxt<'tcx> {
}
}
EvalResult::Deny { feature, reason, issue }
EvalResult::Deny { feature, reason, issue, is_soft }
}
Some(_) => {
// Stable APIs are always ok to call and deprecated APIs are
@ -767,8 +777,8 @@ impl<'tcx> TyCtxt<'tcx> {
pub fn check_stability(self, def_id: DefId, id: Option<HirId>, span: Span) {
match self.eval_stability(def_id, id, span) {
EvalResult::Allow => {}
EvalResult::Deny { feature, reason, issue } =>
report_unstable(self.sess, feature, reason, issue, span),
EvalResult::Deny { feature, reason, issue, is_soft } =>
report_unstable(self.sess, feature, reason, issue, is_soft, span),
EvalResult::Unmarked => {
// The API could be uncallable for other reasons, for example when a private module
// was referenced.