instantly_dangling_pointer: rename to dangling_pointers_from_temporaries

Author: GrigorenkoPV

compiler/rustc_lint/src/dangling.rs

@@ -35,7 +35,7 @@ declare_lint! {
 // 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! {
-    /// The `instantly_dangling_pointer` lint detects getting a pointer to data
+    /// The `dangling_pointers_from_temporaries` lint detects getting a pointer to data
     /// of a temporary that will immediately get dropped.
     ///
     /// ### Example
@@ -63,20 +63,12 @@ declare_lint! {
     ///
     /// If you need stronger guarantees, consider using references instead,
     /// as they are statically verified by the borrow-checker to never dangle.
-    ///
-    /// Note: This lint does **not** get triggered by methods & functions
-    /// that intentionally produce dangling pointers, such as:
-    ///
-    /// - `core::ptr::dangling` & `core::ptr::dangling_mut`
-    /// - `core::ptr::NonNull::dangling`
-    /// - `std::alloc::Layout::dangling`
-    ///
-    pub INSTANTLY_DANGLING_POINTER,
+    pub DANGLING_POINTERS_FROM_TEMPORARIES,
     Warn,
-    "detects getting a pointer that will immediately dangle"
+    "detects getting a pointer from a temporary"
 }
 
-declare_lint_pass!(DanglingPointers => [TEMPORARY_CSTRING_AS_PTR, INSTANTLY_DANGLING_POINTER]);
+declare_lint_pass!(DanglingPointers => [TEMPORARY_CSTRING_AS_PTR, DANGLING_POINTERS_FROM_TEMPORARIES]);
 
 impl<'tcx> LateLintPass<'tcx> for DanglingPointers {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
@@ -111,7 +103,7 @@ impl<'tcx> LateLintPass<'tcx> for DanglingPointers {
             && is_interesting(cx, ty)
         {
             cx.emit_span_lint(
-                INSTANTLY_DANGLING_POINTER,
+                DANGLING_POINTERS_FROM_TEMPORARIES,
                 method.ident.span,
                 InstantlyDangling {
                     callee: method.ident.name,

library/alloc/tests/boxed.rs

@@ -5,8 +5,11 @@ use core::ptr::NonNull;
 
 #[test]
 // FIXME(GrigorenkoPV)
-#[allow(unknown_lints, reason = "`instantly_dangling_pointer` does not exist at stage 0 yet")]
-#[allow(instantly_dangling_pointer)]
+#[allow(
+    unknown_lints,
+    reason = "`dangling_pointers_from_temporaries` does not exist at stage 0 yet"
+)]
+#[allow(dangling_pointers_from_temporaries)]
 fn uninitialized_zero_size_box() {
     assert_eq!(
         &*Box::<()>::new_uninit() as *const _,

tests/ui/consts/zst_no_llvm_alloc.rs

@@ -17,7 +17,7 @@ fn main() {
 
     // The exact addresses returned by these library functions are not necessarily stable guarantees
     // but for now we assert that we're still matching.
-    #[expect(instantly_dangling_pointer)]
+    #[expect(dangling_pointers_from_temporaries)]
     {
         assert_eq!(<Vec<i32>>::new().as_ptr(), <&[i32]>::default().as_ptr());
         assert_eq!(<Box<[i32]>>::default().as_ptr(), (&[]).as_ptr());

tests/ui/lint/dangling-ptr/instantly-dangling-pointer-allow.rs renamed to tests/ui/lint/dangling-ptr/allow.rs

@@ -2,7 +2,7 @@
 
 // This should not ICE.
 
-#![allow(instantly_dangling_pointer)]
+#![allow(dangling_pointers_from_temporaries)]
 
 fn main() {
     dbg!(String::new().as_ptr());

tests/ui/lint/dangling-ptr/instantly-dangling-pointer-methods.rs

@@ -1,11 +1,11 @@
-#![deny(instantly_dangling_pointer)]
+#![deny(dangling_pointers_from_temporaries)]
 
 const MAX_PATH: usize = 260;
 fn main() {
     let str1 = String::with_capacity(MAX_PATH).as_mut_ptr();
-    //~^ ERROR [instantly_dangling_pointer]
+    //~^ ERROR [dangling_pointers_from_temporaries]
     let str2 = String::from("TotototototototototototototototototoT").as_ptr();
-    //~^ ERROR [instantly_dangling_pointer]
+    //~^ ERROR [dangling_pointers_from_temporaries]
     unsafe {
         std::ptr::copy_nonoverlapping(str2, str1, 30);
         println!("{:?}", String::from_raw_parts(str1, 30, 30));

tests/ui/lint/dangling-ptr/instantly-dangling-pointer-types.rs

@@ -1,5 +1,5 @@
 error: getting a pointer from a temporary `String` will result in a dangling pointer
-  --> $DIR/instantly-dangling-pointer-issue123613.rs:5:48
+  --> $DIR/issue123613.rs:5:48
    |
 LL |     let str1 = String::with_capacity(MAX_PATH).as_mut_ptr();
    |                ------------------------------- ^^^^^^^^^^ this pointer will immediately be invalid
@@ -9,13 +9,13 @@ LL |     let str1 = String::with_capacity(MAX_PATH).as_mut_ptr();
    = note: pointers do not have a lifetime; when calling `as_mut_ptr` the `String` 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
 note: the lint level is defined here
-  --> $DIR/instantly-dangling-pointer-issue123613.rs:1:9
+  --> $DIR/issue123613.rs:1:9
    |
-LL | #![deny(instantly_dangling_pointer)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #![deny(dangling_pointers_from_temporaries)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: getting a pointer from a temporary `String` will result in a dangling pointer
-  --> $DIR/instantly-dangling-pointer-issue123613.rs:7:70
+  --> $DIR/issue123613.rs:7:70
    |
 LL |     let str2 = String::from("TotototototototototototototototototoT").as_ptr();
    |                ----------------------------------------------------- ^^^^^^ this pointer will immediately be invalid

tests/ui/lint/dangling-ptr/instantly-dangling-pointer-issue123613.rs renamed to tests/ui/lint/dangling-ptr/issue123613.rs

@@ -0,0 +1,6 @@
+#![deny(dangling_pointers_from_temporaries)]
+
+fn main() {
+    vec![0u8].as_ptr(); //~ ERROR [dangling_pointers_from_temporaries]
+    vec![0u8].as_mut_ptr(); //~ ERROR [dangling_pointers_from_temporaries]
+}

tests/ui/lint/dangling-ptr/instantly-dangling-pointer-issue123613.stderr renamed to tests/ui/lint/dangling-ptr/issue123613.stderr

@@ -1,5 +1,5 @@
 error: getting a pointer from a temporary `Vec<u8>` will result in a dangling pointer
-  --> $DIR/instantly-dangling-pointer-methods.rs:4:15
+  --> $DIR/methods.rs:4:15
    |
 LL |     vec![0u8].as_ptr();
    |     --------- ^^^^^^ this pointer will immediately be invalid
@@ -9,13 +9,13 @@ LL |     vec![0u8].as_ptr();
    = note: pointers do not have a lifetime; when calling `as_ptr` the `Vec<u8>` 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
 note: the lint level is defined here
-  --> $DIR/instantly-dangling-pointer-methods.rs:1:9
+  --> $DIR/methods.rs:1:9
    |
-LL | #![deny(instantly_dangling_pointer)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | #![deny(dangling_pointers_from_temporaries)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: getting a pointer from a temporary `Vec<u8>` will result in a dangling pointer
-  --> $DIR/instantly-dangling-pointer-methods.rs:5:15
+  --> $DIR/methods.rs:5:15
    |
 LL |     vec![0u8].as_mut_ptr();
    |     --------- ^^^^^^^^^^ this pointer will immediately be invalid