decouple "reporting in deps" from future incompatibility reason

2025-06-03 01:29:36 +02:00
parent 52882f6522
commit 9b7da4deb2
4 changed files with 67 additions and 82 deletions
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -126,7 +126,7 @@ fn lints_that_dont_need_to_run(tcx: TyCtxt<'_>, (): ()) -> UnordSet<LintId> {
        .filter(|lint| {
            // Lints that show up in future-compat reports must always be run.
            let has_future_breakage =
-                lint.future_incompatible.is_some_and(|fut| fut.reason.has_future_breakage());
+                lint.future_incompatible.is_some_and(|fut| fut.report_in_deps);
            !has_future_breakage && !lint.eval_always
        })
        .filter(|lint| {
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -178,8 +178,9 @@ declare_lint! {
    Warn,
    "applying forbid to lint-groups",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #81670 <https://github.com/rust-lang/rust/issues/81670>",
+        report_in_deps: true,
    };
 }

@@ -214,7 +215,7 @@ declare_lint! {
    Deny,
    "ill-formed attribute inputs that were previously accepted and used in practice",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #57571 <https://github.com/rust-lang/rust/issues/57571>",
    };
    crate_level_only
@@ -251,8 +252,9 @@ declare_lint! {
    Deny,
    "conflicts between `#[repr(..)]` hints that were previously accepted and used in practice",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #68585 <https://github.com/rust-lang/rust/issues/68585>",
+        report_in_deps: true,
    };
 }

@@ -1240,8 +1242,9 @@ declare_lint! {
    Deny,
    "detect public re-exports of private extern crates",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #127909 <https://github.com/rust-lang/rust/issues/127909>",
+        report_in_deps: true,
    };
 }

@@ -1270,8 +1273,9 @@ declare_lint! {
    Deny,
    "type parameter default erroneously allowed in invalid location",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
+        report_in_deps: true,
    };
 }

@@ -1409,7 +1413,7 @@ declare_lint! {
    Deny,
    "patterns in functions without body were erroneously allowed",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
    };
 }
@@ -1453,8 +1457,9 @@ declare_lint! {
    Deny,
    "detects missing fragment specifiers in unused `macro_rules!` patterns",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
+        report_in_deps: true,
    };
 }

@@ -1495,7 +1500,7 @@ declare_lint! {
    Warn,
    "detects generic lifetime arguments in path segments with late bound lifetime parameters",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
    };
 }
@@ -2122,8 +2127,9 @@ declare_lint! {
    Deny,
    "detects proc macro derives using inaccessible names from parent modules",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #83583 <https://github.com/rust-lang/rust/issues/83583>",
+        report_in_deps: true,
    };
 }

@@ -2225,7 +2231,7 @@ declare_lint! {
    "macro-expanded `macro_export` macros from the current crate \
     cannot be referred to by absolute paths",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
    };
    crate_level_only
@@ -2346,7 +2352,7 @@ declare_lint! {
    Deny,
    "ambiguous associated items",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #57644 <https://github.com/rust-lang/rust/issues/57644>",
    };
 }
@@ -2362,8 +2368,9 @@ declare_lint! {
    Deny,
    "a feature gate that doesn't break dependent crates",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #64266 <https://github.com/rust-lang/rust/issues/64266>",
+        report_in_deps: true,
    };
 }

@@ -2674,7 +2681,7 @@ declare_lint! {
    Warn,
    "detects a generic constant is used in a type without a emitting a warning",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #76200 <https://github.com/rust-lang/rust/issues/76200>",
    };
 }
@@ -2733,7 +2740,7 @@ declare_lint! {
    Warn,
    "uninhabited static",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #74840 <https://github.com/rust-lang/rust/issues/74840>",
    };
 }
@@ -2866,7 +2873,7 @@ declare_lint! {
    Warn,
    "detect unsupported use of `Self` from outer item",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #124186 <https://github.com/rust-lang/rust/issues/124186>",
    };
 }
@@ -2912,8 +2919,9 @@ declare_lint! {
    Warn,
    "trailing semicolon in macro body used as expression",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #79813 <https://github.com/rust-lang/rust/issues/79813>",
+        report_in_deps: true,
    };
 }

@@ -2959,7 +2967,7 @@ declare_lint! {
    Warn,
    "detects derive helper attributes that are used before they are introduced",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #79202 <https://github.com/rust-lang/rust/issues/79202>",
    };
 }
@@ -3126,7 +3134,7 @@ declare_lint! {
    Warn,
    "transparent type contains an external ZST that is marked #[non_exhaustive] or contains private fields",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #78586 <https://github.com/rust-lang/rust/issues/78586>",
    };
 }
@@ -3177,7 +3185,7 @@ declare_lint! {
    Warn,
    "unstable syntax can change at any point in the future, causing a hard error!",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #65860 <https://github.com/rust-lang/rust/issues/65860>",
    };
 }
@@ -3685,8 +3693,9 @@ declare_lint! {
    Warn,
    "use of unsupported calling convention for function pointer",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #130260 <https://github.com/rust-lang/rust/issues/130260>",
+        report_in_deps: true,
    };
 }

@@ -4368,7 +4377,7 @@ declare_lint! {
    Warn,
    "detects certain glob imports that require reporting an ambiguity error",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #114095 <https://github.com/rust-lang/rust/issues/114095>",
    };
 }
@@ -4523,7 +4532,7 @@ declare_lint! {
    Deny,
    "elided lifetimes cannot be used in associated constants in impls",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #115010 <https://github.com/rust-lang/rust/issues/115010>",
    };
 }
@@ -4570,7 +4579,7 @@ declare_lint! {
    Warn,
    "detects certain macro bindings that should not be re-exported",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #120192 <https://github.com/rust-lang/rust/issues/120192>",
    };
 }
@@ -4635,7 +4644,7 @@ declare_lint! {
    Warn,
    "impl contains type parameters that are not covered",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #124559 <https://github.com/rust-lang/rust/issues/124559>",
    };
 }
@@ -4799,7 +4808,7 @@ declare_lint! {
    Warn,
    "detects out of scope calls to `macro_rules` in key-value attributes",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #124535 <https://github.com/rust-lang/rust/issues/124535>",
    };
 }
@@ -5040,8 +5049,9 @@ declare_lint! {
    Warn,
    "detects code relying on rustc's non-spec-compliant wasm C ABI",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #138762 <https://github.com/rust-lang/rust/issues/138762>",
+        report_in_deps: true,
    };
 }

@@ -5081,7 +5091,8 @@ declare_lint! {
    Warn,
    "detects code that could be affected by ABI issues on aarch64 softfloat targets",
    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseError,
        reference: "issue #134375 <https://github.com/rust-lang/rust/issues/134375>",
+        report_in_deps: true,
    };
 }
--- a/compiler/rustc_lint_defs/src/lib.rs
+++ b/compiler/rustc_lint_defs/src/lib.rs
@@ -361,6 +361,18 @@ pub struct FutureIncompatibleInfo {
    /// Set to false for lints that already include a more detailed
    /// explanation.
    pub explain_reason: bool,
+    /// If set to `true`, this will make future incompatibility warnings show up in cargo's
+    /// reports.
+    ///
+    /// When a future incompatibility warning is first inroduced, set this to `false`
+    /// (or, rather, don't override the default). This allows crate developers an opportunity
+    /// to fix the warning before blasting all dependents with a warning they can't fix
+    /// (dependents have to wait for a new release of the affected crate to be published).
+    ///
+    /// After a lint has been in this state for a while, consider setting this to true, so it
+    /// warns for everyone. It is a good signal that it is ready if you can determine that all
+    /// or most affected crates on crates.io have been updated.
+    pub report_in_deps: bool,
 }

 /// The reason for future incompatibility
@@ -380,46 +392,24 @@ pub struct FutureIncompatibleInfo {
 pub enum FutureIncompatibilityReason {
    /// This will be an error in a future release for all editions
    ///
-    /// This will *not* show up in cargo's future breakage report.
-    /// The warning will hence only be seen in local crates, not in dependencies.
-    ///
    /// Choose this variant when you are first introducing a "future
    /// incompatible" warning that is intended to eventually be fixed in the
-    /// future. This allows crate developers an opportunity to fix the warning
-    /// before blasting all dependents with a warning they can't fix
-    /// (dependents have to wait for a new release of the affected crate to be
-    /// published).
+    /// future.
    ///
-    /// After a lint has been in this state for a while, consider graduating
-    /// it to [`FutureIncompatibilityReason::FutureReleaseErrorReportInDeps`].
-    FutureReleaseErrorDontReportInDeps,
-    /// This will be an error in a future release, and
-    /// Cargo should create a report even for dependencies
-    ///
-    /// This is the *only* reason that will make future incompatibility warnings show up in cargo's
-    /// reports. All other future incompatibility warnings are not visible when they occur in a
-    /// dependency.
-    ///
-    /// Choose this variant after the lint has been sitting in the
-    /// [`FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps`]
-    /// state for a while, and you feel like it is ready to graduate to
-    /// warning everyone. It is a good signal that it is ready if you can
-    /// determine that all or most affected crates on crates.io have been
-    /// updated.
+    /// After a lint has been in this state for a while and you feel like it is ready to graduate
+    /// to warning everyone, consider setting [`FutureIncompatibleInfo::report_in_deps`] to true.
+    /// (see it's documentation for more guidance)
    ///
    /// After some period of time, lints with this variant can be turned into
    /// hard errors (and the lint removed). Preferably when there is some
    /// confidence that the number of impacted projects is very small (few
    /// should have a broken dependency in their dependency tree).
-    ///
-    /// [`EditionAndFutureReleaseError`]: FutureIncompatibilityReason::EditionAndFutureReleaseError
-    FutureReleaseErrorReportInDeps,
+    FutureReleaseError,
    /// Code that changes meaning in some way in a
    /// future release.
    ///
    /// Choose this variant when the semantics of existing code is changing,
-    /// (as opposed to
-    /// [`FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps`],
+    /// (as opposed to [`FutureIncompatibilityReason::FutureReleaseError`],
    /// which is for when code is going to be rejected in the future).
    FutureReleaseSemanticsChange,
    /// Previously accepted code that will become an
@@ -454,13 +444,12 @@ pub enum FutureIncompatibilityReason {
    /// This will be an error in the provided edition *and* in a future
    /// release.
    ///
-    /// This variant a combination of [`FutureReleaseErrorDontReportInDeps`]
-    /// and [`EditionError`]. This is useful in rare cases when we
-    /// want to have "preview" of a breaking change in an edition, but do a
-    /// breaking change later on all editions anyway.
+    /// This variant a combination of [`FutureReleaseError`] and [`EditionError`].
+    /// This is useful in rare cases when we want to have "preview" of a breaking
+    /// change in an edition, but do a breaking change later on all editions anyway.
    ///
    /// [`EditionError`]: FutureIncompatibilityReason::EditionError
-    /// [`FutureReleaseErrorDontReportInDeps`]: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps
+    /// [`FutureReleaseError`]: FutureIncompatibilityReason::FutureReleaseError
    EditionAndFutureReleaseError(Edition),
    /// This will change meaning in the provided edition *and* in a future
    /// release.
@@ -478,7 +467,7 @@ pub enum FutureIncompatibilityReason {
    /// Choose this variant if the built-in text of the diagnostic of the
    /// other variants doesn't match your situation. This is behaviorally
    /// equivalent to
-    /// [`FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps`].
+    /// [`FutureIncompatibilityReason::FutureReleaseError`].
    Custom(&'static str),
 }

@@ -490,34 +479,20 @@ impl FutureIncompatibilityReason {
            | Self::EditionAndFutureReleaseError(e)
            | Self::EditionAndFutureReleaseSemanticsChange(e) => Some(e),

-            FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps
-            | FutureIncompatibilityReason::FutureReleaseErrorReportInDeps
+            FutureIncompatibilityReason::FutureReleaseError
            | FutureIncompatibilityReason::FutureReleaseSemanticsChange
            | FutureIncompatibilityReason::Custom(_) => None,
        }
    }
-
-    pub fn has_future_breakage(self) -> bool {
-        match self {
-            FutureIncompatibilityReason::FutureReleaseErrorReportInDeps => true,
-
-            FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps
-            | FutureIncompatibilityReason::FutureReleaseSemanticsChange
-            | FutureIncompatibilityReason::EditionError(_)
-            | FutureIncompatibilityReason::EditionSemanticsChange(_)
-            | FutureIncompatibilityReason::EditionAndFutureReleaseError(_)
-            | FutureIncompatibilityReason::EditionAndFutureReleaseSemanticsChange(_)
-            | FutureIncompatibilityReason::Custom(_) => false,
-        }
-    }
 }

 impl FutureIncompatibleInfo {
    pub const fn default_fields_for_macro() -> Self {
        FutureIncompatibleInfo {
            reference: "",
-            reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+            reason: FutureIncompatibilityReason::FutureReleaseError,
            explain_reason: true,
+            report_in_deps: false,
        }
    }
 }
--- a/compiler/rustc_middle/src/lint.rs
+++ b/compiler/rustc_middle/src/lint.rs
@@ -299,7 +299,7 @@ pub fn lint_level(
        let has_future_breakage = future_incompatible.map_or(
            // Default allow lints trigger too often for testing.
            sess.opts.unstable_opts.future_incompat_test && lint.default_level != Level::Allow,
-            |incompat| incompat.reason.has_future_breakage(),
+            |incompat| incompat.report_in_deps,
        );

        // Convert lint level to error level.
@@ -370,8 +370,7 @@ pub fn lint_level(

        if let Some(future_incompatible) = future_incompatible {
            let explanation = match future_incompatible.reason {
-                FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps
-                | FutureIncompatibilityReason::FutureReleaseErrorReportInDeps => {
+                FutureIncompatibilityReason::FutureReleaseError => {
                    "this was previously accepted by the compiler but is being phased out; \
                         it will become a hard error in a future release!"
                        .to_owned()