Rename the lint and fix the tests

compiler/rustc_lint/messages.ftl

@@ -135,7 +135,7 @@ lint_builtin_overridden_symbol_name =
 lint_builtin_overridden_symbol_section =
     the program's behavior with overridden link sections on items is unpredictable and Rust cannot provide guarantees when you manually override them
 
-lint_builtin_return_local_variable_ptr = returning a pointer to stack memory associated with a local variable
+lint_builtin_returning_pointers_to_local_variables = returning a pointer to stack memory associated with a local variable
 
 lint_builtin_special_module_name_used_lib = found module declaration for lib.rs
     .note = lib.rs is the root of this crate's library target

compiler/rustc_lint/src/builtin.rs

@@ -54,9 +54,9 @@ use crate::lints::{
     BuiltinEllipsisInclusiveRangePatternsLint, BuiltinExplicitOutlives,
     BuiltinExplicitOutlivesSuggestion, BuiltinFeatureIssueNote, BuiltinIncompleteFeatures,
     BuiltinIncompleteFeaturesHelp, BuiltinInternalFeatures, BuiltinKeywordIdents,
-    BuiltinLocalVariablePointerImpl, BuiltinMissingCopyImpl, BuiltinMissingDebugImpl,
-    BuiltinMissingDoc, BuiltinMutablesTransmutes, BuiltinNoMangleGeneric,
-    BuiltinNonShorthandFieldPatterns, BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds,
+    BuiltinMissingCopyImpl, BuiltinMissingDebugImpl, BuiltinMissingDoc, BuiltinMutablesTransmutes,
+    BuiltinNoMangleGeneric, BuiltinNonShorthandFieldPatterns,
+    BuiltinReturningPointersToLocalVariables, BuiltinSpecialModuleNameUsed, BuiltinTrivialBounds,
     BuiltinTypeAliasBounds, BuiltinUngatedAsyncFnTrackCaller, BuiltinUnpermittedTypeInit,
     BuiltinUnpermittedTypeInitSub, BuiltinUnreachablePub, BuiltinUnsafe, BuiltinUnstableFeatures,
     BuiltinUnusedDocComment, BuiltinUnusedDocCommentSub, BuiltinWhileTrue, InvalidAsmLabel,
@@ -2987,9 +2987,9 @@ impl<'tcx> LateLintPass<'tcx> for AsmLabels {
 }
 
 declare_lint! {
-    /// The `return_local_variable_ptr` lint detects when pointer to stack
-    /// memory associated with a local variable is returned. That pointer
-    /// is immediately dangling.
+    /// The `returning_pointers_to_local_variables` lint detects when pointer
+    /// to stack memory associated with a local variable is returned. That
+    /// pointer is immediately dangling.
     ///
     /// ### Example
     ///
@@ -3008,14 +3008,14 @@ declare_lint! {
     ///
     /// Returning a pointer to memory refering to a local variable will always
     /// end up in a dangling pointer after returning.
-    pub RETURN_LOCAL_VARIABLE_PTR,
+    pub RETURNING_POINTERS_TO_LOCAL_VARIABLES,
     Warn,
     "returning a pointer to stack memory associated with a local variable",
 }
 
-declare_lint_pass!(ReturnLocalVariablePointer => [RETURN_LOCAL_VARIABLE_PTR]);
+declare_lint_pass!(ReturningPointersToLocalVariables => [RETURNING_POINTERS_TO_LOCAL_VARIABLES]);
 
-impl<'tcx> LateLintPass<'tcx> for ReturnLocalVariablePointer {
+impl<'tcx> LateLintPass<'tcx> for ReturningPointersToLocalVariables {
     fn check_fn(
         &mut self,
         cx: &LateContext<'tcx>,
@@ -3061,7 +3061,7 @@ impl<'tcx> LateLintPass<'tcx> for ReturnLocalVariablePointer {
     }
 }
 
-impl ReturnLocalVariablePointer {
+impl ReturningPointersToLocalVariables {
     /// Evaluates the return expression of a function and emits a lint if it
     /// returns a pointer to a local variable.
     fn maybe_lint_return_expr<'tcx>(cx: &LateContext<'tcx>, return_expr: &hir::Expr<'tcx>) {
@@ -3078,9 +3078,9 @@ impl ReturnLocalVariablePointer {
             ) = addr_expr.kind
             {
                 cx.emit_span_lint(
-                    RETURN_LOCAL_VARIABLE_PTR,
+                    RETURNING_POINTERS_TO_LOCAL_VARIABLES,
                     return_expr.span,
-                    BuiltinLocalVariablePointerImpl,
+                    BuiltinReturningPointersToLocalVariables,
                 );
             }
         }

compiler/rustc_lint/src/lib.rs

@@ -241,7 +241,7 @@ late_lint_methods!(
             IfLetRescope: IfLetRescope::default(),
             StaticMutRefs: StaticMutRefs,
             UnqualifiedLocalImports: UnqualifiedLocalImports,
-            ReturnLocalVariablePointer : ReturnLocalVariablePointer,
+            ReturningPointersToLocalVariables : ReturningPointersToLocalVariables,
         ]
     ]
 );

compiler/rustc_lint/src/lints.rs

@@ -532,8 +532,8 @@ pub(crate) enum BuiltinSpecialModuleNameUsed {
 }
 
 #[derive(LintDiagnostic)]
-#[diag(lint_builtin_return_local_variable_ptr)]
-pub(crate) struct BuiltinLocalVariablePointerImpl;
+#[diag(lint_builtin_returning_pointers_to_local_variables)]
+pub(crate) struct BuiltinReturningPointersToLocalVariables;
 
 // deref_into_dyn_supertrait.rs
 #[derive(LintDiagnostic)]

src/tools/miri/tests/fail/validity/dangling_ref3.rs

@@ -1,5 +1,6 @@
 // Make sure we catch this even without Stacked Borrows
 //@compile-flags: -Zmiri-disable-stacked-borrows
+#![allow(returning_pointers_to_local_variables)]
 use std::mem;
 
 fn dangling() -> *const u8 {

tests/ui/lint/lint-returning-pointers-to-local-variables.rs

@@ -0,0 +1,29 @@
+//@ check-pass
+
+#![warn(returning_pointers_to_local_variables)]
+
+fn foo() -> *const u32 {
+    let empty = 42u32;
+    return &empty as *const _;
+    //~^ WARN returning a pointer to stack memory associated with a local variable
+}
+
+fn bar() -> *const u32 {
+    let empty = 42u32;
+    &empty as *const _
+    //~^ WARN returning a pointer to stack memory associated with a local variable
+}
+
+fn baz() -> *const u32 {
+    let empty = 42u32;
+    return ∅
+    //~^ WARN returning a pointer to stack memory associated with a local variable
+}
+
+fn faa() -> *const u32 {
+    let empty = 42u32;
+    &empty
+    //~^ WARN returning a pointer to stack memory associated with a local variable
+}
+
+fn main() {}

tests/ui/lint/lint-return-local-variable-ptr.stderr → tests/ui/lint/lint-returning-pointers-to-local-variables.stderr

@@ -1,29 +1,29 @@
 warning: returning a pointer to stack memory associated with a local variable
-  --> $DIR/lint-return-local-variable-ptr.rs:7:12
+  --> $DIR/lint-returning-pointers-to-local-variables.rs:7:12
    |
 LL |     return &empty as *const _;
    |            ^^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/lint-return-local-variable-ptr.rs:3:9
+  --> $DIR/lint-returning-pointers-to-local-variables.rs:3:9
    |
-LL | #![warn(return_local_variable_ptr)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #![warn(returning_pointers_to_local_variables)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: returning a pointer to stack memory associated with a local variable
-  --> $DIR/lint-return-local-variable-ptr.rs:12:5
+  --> $DIR/lint-returning-pointers-to-local-variables.rs:13:5
    |
 LL |     &empty as *const _
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: returning a pointer to stack memory associated with a local variable
-  --> $DIR/lint-return-local-variable-ptr.rs:17:12
+  --> $DIR/lint-returning-pointers-to-local-variables.rs:19:12
    |
 LL |     return ∅
    |            ^^^^^^
 
 warning: returning a pointer to stack memory associated with a local variable
-  --> $DIR/lint-return-local-variable-ptr.rs:22:5
+  --> $DIR/lint-returning-pointers-to-local-variables.rs:25:5
    |
 LL |     &empty
    |     ^^^^^^