temporary_as_ptr: rename to instantly_dangling_pointer

Author: GrigorenkoPV

compiler/rustc_lint/messages.ftl

@@ -405,6 +405,12 @@ lint_incomplete_include =
 
 lint_inner_macro_attribute_unstable = inner macro attributes are unstable
 
+lint_instantly_dangling = this pointer will immediately dangle
+    .ptr_label = this pointer will be invalid
+    .temporary_label = this `{$ty}` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
+    .note = pointers do not have a lifetime; when calling `{$method}` the `{$ty}` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
+    .help = for more information, see https://doc.rust-lang.org/reference/destructors.html
+
 lint_invalid_asm_label_binary = avoid using labels containing only the digits `0` and `1` in inline assembly
     .label = use a different label that doesn't start with `0` or `1`
     .help = start numbering with `2` instead
@@ -755,12 +761,6 @@ lint_suspicious_double_ref_deref =
 lint_tail_expr_drop_order = these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
     .label = these values have significant drop implementation and will observe changes in drop order under Edition 2024
 
-lint_temporary_as_ptr = getting the inner pointer of a temporary `{$ty}`
-    .as_ptr_label = this pointer will be invalid
-    .temporary_label = this `{$ty}` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
-    .note = pointers do not have a lifetime; when calling `{$method}` the `{$ty}` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
-    .help = for more information, see https://doc.rust-lang.org/reference/destructors.html
-
 lint_trailing_semi_macro = trailing semicolon in macro used in expression position
     .note1 = macro invocations at the end of a block are treated as expressions
     .note2 = to ignore the value produced by the macro, add a semicolon after the invocation of `{$name}`

compiler/rustc_lint/src/lib.rs

@@ -225,7 +225,7 @@ late_lint_methods!(
             UngatedAsyncFnTrackCaller: UngatedAsyncFnTrackCaller,
             ShadowedIntoIter: ShadowedIntoIter,
             DropTraitConstraints: DropTraitConstraints,
-            TemporaryCStringAsPtr: TemporaryCStringAsPtr,
+            InstantlyDanglingPtr: InstantlyDanglingPtr,
             NonPanicFmt: NonPanicFmt,
             NoopMethodCall: NoopMethodCall,
             EnumIntrinsicsNonEnums: EnumIntrinsicsNonEnums,

compiler/rustc_lint/src/lints.rs

@@ -1126,14 +1126,14 @@ pub struct IgnoredUnlessCrateSpecified<'a> {
 
 // methods.rs
 #[derive(LintDiagnostic)]
-#[diag(lint_temporary_as_ptr)]
+#[diag(lint_instantly_dangling)]
 #[note]
 #[help]
-pub struct TemporaryAsPtr {
+pub struct InstantlyDangling {
     pub method: Symbol,
     pub ty: String,
-    #[label(lint_as_ptr_label)]
-    pub as_ptr_span: Span,
+    #[label(lint_ptr_label)]
+    pub ptr_span: Span,
     #[label(lint_temporary_label)]
     pub temporary_span: Span,
 }

compiler/rustc_lint/src/methods.rs

@@ -3,7 +3,7 @@ use rustc_middle::ty::Ty;
 use rustc_session::{declare_lint, declare_lint_pass};
 use rustc_span::symbol::{sym, Ident};
 
-use crate::lints::TemporaryAsPtr;
+use crate::lints::InstantlyDangling;
 use crate::{LateContext, LateLintPass, LintContext};
 
 declare_lint! {
@@ -32,16 +32,17 @@ declare_lint! {
     "detects getting the inner pointer of a temporary `CString`"
 }
 
+// FIXME: does not catch UnsafeCell::get
+// FIXME: does not catch getting a ref to a temporary and then converting it to a ptr
 declare_lint! {
-    /// TODO
-    pub TEMPORARY_AS_PTR,
+    pub INSTANTLY_DANGLING_POINTER,
     Warn,
-    "detects getting the inner pointer of a temporary container"
+    "detects getting a pointer that will immediately dangle"
 }
 
-declare_lint_pass!(TemporaryCStringAsPtr => [TEMPORARY_CSTRING_AS_PTR, TEMPORARY_AS_PTR]);
+declare_lint_pass!(InstantlyDanglingPtr => [TEMPORARY_CSTRING_AS_PTR, INSTANTLY_DANGLING_POINTER]);
 
-impl<'tcx> LateLintPass<'tcx> for TemporaryCStringAsPtr {
+impl<'tcx> LateLintPass<'tcx> for InstantlyDanglingPtr {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         // We have a method call.
         let ExprKind::MethodCall(method, receiver, _args, _span) = expr.kind else {
@@ -70,17 +71,17 @@ impl<'tcx> LateLintPass<'tcx> for TemporaryCStringAsPtr {
         };
 
         let span = method.ident.span;
-        let decorator = TemporaryAsPtr {
+        let decorator = InstantlyDangling {
             method: method_name,
             ty: ty.to_string(),
-            as_ptr_span: method_span,
+            ptr_span: method_span,
             temporary_span: receiver.span,
         };
 
         if is_cstring {
             cx.emit_span_lint(TEMPORARY_CSTRING_AS_PTR, span, decorator);
         } else {
-            cx.emit_span_lint(TEMPORARY_AS_PTR, span, decorator);
+            cx.emit_span_lint(INSTANTLY_DANGLING_POINTER, span, decorator);
         };
     }
 }