bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Rollup merge of #94670 - xFrednet:rfc-2383-expect-impl-after-party, r=flip1995,wesleywiser

Browse source 
Improve `expect` impl and handle `#[expect(unfulfilled_lint_expectations)]` (RFC 2383)

This PR updates unstable `ExpectationIds` in stashed diagnostics and adds some asserts to ensure that the stored expectations are really empty in the end. Additionally, it handles the `#[expect(unfulfilled_lint_expectations)]` case.

According to the [Errors and lints docs](https://rustc-dev-guide.rust-lang.org/diagnostics.html#diagnostic-levels) the `error` level should only be used _"when the compiler detects a problem that makes it unable to compile the program"_. As this isn't the case with `#[expect(unfulfilled_lint_expectations)]` I decided to only create a warning. To avoid adding a new lint only for this case, I simply emit a `unfulfilled_lint_expectations` diagnostic with an additional note.

---

r? `@wesleywiser` I'm requesting a review from you since you reviewed the previous PR https://github.com/rust-lang/rust/pull/87835. You are welcome to reassign it if you're busy 🙃

rfc: [RFC-2383](https://rust-lang.github.io/rfcs/2383-lint-reasons.html)

tracking issue: https://github.com/rust-lang/rust/issues/85549

cc: `@flip1995` In case you're also interested in this :)
This commit is contained in:
Matthias Krüger 2022-03-14 17:24:58 +01:00 • committed by GitHub
commit 6548a368c8
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
8 changed files with 167 additions and 30 deletions
Download patch file Download diff file Expand all files Collapse all files

9
compiler/rustc_lint/src/expect.rs
View file

@ -30,10 +30,6 @@ fn emit_unfulfilled_expectation_lint(
hir_id: HirId,
expectation: &LintExpectation,
) {
// FIXME: The current implementation doesn't cover cases where the
// `unfulfilled_lint_expectations` is actually expected by another lint
// expectation. This can be added here by checking the lint level and
// retrieving the `LintExpectationId` if it was expected.
tcx.struct_span_lint_hir(
builtin::UNFULFILLED_LINT_EXPECTATIONS,
hir_id,
@ -43,6 +39,11 @@ fn emit_unfulfilled_expectation_lint(
if let Some(rationale) = expectation.reason {
diag.note(&rationale.as_str());
}
if expectation.is_unfulfilled_lint_expectations {
diag.note("the `unfulfilled_lint_expectations` lint can't be expected and will always produce this message");
}
diag.emit();
},
);

36
compiler/rustc_lint/src/levels.rs
View file

@ -14,7 +14,7 @@ use rustc_middle::lint::{
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::{RegisteredTools, TyCtxt};
use rustc_session::lint::{
builtin::{self, FORBIDDEN_LINT_GROUPS},
builtin::{self, FORBIDDEN_LINT_GROUPS, UNFULFILLED_LINT_EXPECTATIONS},
Level, Lint, LintExpectationId, LintId,
};
use rustc_session::parse::{add_feature_diagnostics, feature_err};
@ -218,6 +218,14 @@ impl<'s> LintLevelsBuilder<'s> {
}
}
}
// The lint `unfulfilled_lint_expectations` can't be expected, as it would suppress itself.
// Handling expectations of this lint would add additional complexity with little to no
// benefit. The expect level for this lint will therefore be ignored.
if let Level::Expect(_) = level && id == LintId::of(UNFULFILLED_LINT_EXPECTATIONS) {
return;
}
if let Level::ForceWarn = old_level {
self.current_specs_mut().insert(id, (old_level, old_src));
} else {
@ -350,6 +358,22 @@ impl<'s> LintLevelsBuilder<'s> {
self.store.check_lint_name(&name, tool_name, self.registered_tools);
match &lint_result {
CheckLintNameResult::Ok(ids) => {
// This checks for instances where the user writes `#[expect(unfulfilled_lint_expectations)]`
// in that case we want to avoid overriding the lint level but instead add an expectation that
// can't be fulfilled. The lint message will include an explanation, that the
// `unfulfilled_lint_expectations` lint can't be expected.
if let Level::Expect(expect_id) = level {
// The `unfulfilled_lint_expectations` lint is not part of any lint groups. Therefore. we
// only need to check the slice if it contains a single lint.
let is_unfulfilled_lint_expectations = match ids {
[lint] => *lint == LintId::of(UNFULFILLED_LINT_EXPECTATIONS),
_ => false,
};
self.lint_expectations.push((
expect_id,
LintExpectation::new(reason, sp, is_unfulfilled_lint_expectations),
));
}
let src = LintLevelSource::Node(
meta_item.path.segments.last().expect("empty lint name").ident.name,
sp,
@ -360,10 +384,6 @@ impl<'s> LintLevelsBuilder<'s> {
self.insert_spec(id, (level, src));
}
}
if let Level::Expect(expect_id) = level {
self.lint_expectations
.push((expect_id, LintExpectation::new(reason, sp)));
}
}
CheckLintNameResult::Tool(result) => {
@ -381,7 +401,7 @@ impl<'s> LintLevelsBuilder<'s> {
}
if let Level::Expect(expect_id) = level {
self.lint_expectations
.push((expect_id, LintExpectation::new(reason, sp)));
.push((expect_id, LintExpectation::new(reason, sp, false)));
}
}
Err((Some(ids), ref new_lint_name)) => {
@ -425,7 +445,7 @@ impl<'s> LintLevelsBuilder<'s> {
}
if let Level::Expect(expect_id) = level {
self.lint_expectations
.push((expect_id, LintExpectation::new(reason, sp)));
.push((expect_id, LintExpectation::new(reason, sp, false)));
}
}
Err((None, _)) => {
@ -531,7 +551,7 @@ impl<'s> LintLevelsBuilder<'s> {
}
if let Level::Expect(expect_id) = level {
self.lint_expectations
.push((expect_id, LintExpectation::new(reason, sp)));
.push((expect_id, LintExpectation::new(reason, sp, false)));
}
} else {
panic!("renamed lint does not exist: {}", new_name);