rustup

rust-version

@@ -1 +1 @@
-94b2b15e63c5d2b2a6a0910e3dae554ce9415bf9
+4fd4de7ea358ad6fc28c5780533ea8ccc09e1006

tests/fail/invalid_int.rs

@@ -1,3 +1,4 @@
+#![allow(invalid_value)]
 // Validation makes this fail in the wrong place
 // Make sure we find these even with many checks disabled.
 //@compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation

tests/fail/validity/invalid_bool_uninit.rs

@@ -2,9 +2,9 @@
 
 union MyUninit {
     init: (),
-    uninit: bool,
+    uninit: [bool; 1],
 }
 
 fn main() {
-    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: uninitialized
+    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: constructing invalid value
 }

tests/fail/validity/invalid_bool_uninit.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at [0]: encountered uninitialized memory, but expected a boolean
   --> $DIR/invalid_bool_uninit.rs:LL:CC
    |
 LL |     let _b = unsafe { MyUninit { init: () }.uninit };
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at [0]: encountered uninitialized memory, but expected a boolean
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/fail/validity/invalid_char_uninit.rs

@@ -2,9 +2,9 @@
 
 union MyUninit {
     init: (),
-    uninit: char,
+    uninit: [char; 1],
 }
 
 fn main() {
-    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: uninitialized
+    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: constructing invalid value
 }

tests/fail/validity/invalid_char_uninit.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at [0]: encountered uninitialized memory, but expected a unicode scalar value
   --> $DIR/invalid_char_uninit.rs:LL:CC
    |
 LL |     let _b = unsafe { MyUninit { init: () }.uninit };
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at [0]: encountered uninitialized memory, but expected a unicode scalar value
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/fail/validity/invalid_fnptr_uninit.rs

@@ -2,9 +2,9 @@
 
 union MyUninit {
     init: (),
-    uninit: fn(),
+    uninit: [fn(); 1],
 }
 
 fn main() {
-    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: uninitialized
+    let _b = unsafe { MyUninit { init: () }.uninit }; //~ ERROR: constructing invalid value
 }

tests/fail/validity/invalid_fnptr_uninit.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at [0]: encountered uninitialized memory, but expected a function pointer
   --> $DIR/invalid_fnptr_uninit.rs:LL:CC
    |
 LL |     let _b = unsafe { MyUninit { init: () }.uninit };
-   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at [0]: encountered uninitialized memory, but expected a function pointer
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/fail/validity/uninit_float.rs

@@ -1,8 +1,9 @@
-#![allow(deprecated)]
+#![allow(deprecated, invalid_value)]
 // This test is adapted from https://github.com/rust-lang/miri/issues/1340#issue-600900312.
 
 fn main() {
     // Deliberately using `mem::uninitialized` to make sure that despite all the mitigations, we consider this UB.
-    let _val: f32 = unsafe { std::mem::uninitialized() };
+    // The array avoids a `Scalar` layout which detects uninit without even doing validation.
+    let _val: [f32; 1] = unsafe { std::mem::uninitialized() };
     //~^ ERROR: uninitialized
 }

tests/fail/validity/uninit_float.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at .value[0]: encountered uninitialized bytes
   --> $DIR/uninit_float.rs:LL:CC
    |
-LL |     let _val: f32 = unsafe { std::mem::uninitialized() };
-   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+LL |     let _val: [f32; 1] = unsafe { std::mem::uninitialized() };
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .value[0]: encountered uninitialized bytes
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/fail/validity/uninit_integer.rs

@@ -1,6 +1,8 @@
+#![allow(invalid_value)]
 // This test is from https://github.com/rust-lang/miri/issues/1340#issue-600900312.
 
 fn main() {
-    let _val = unsafe { std::mem::MaybeUninit::<usize>::uninit().assume_init() };
+    // The array avoids a `Scalar` layout which detects uninit without even doing validation.
+    let _val = unsafe { std::mem::MaybeUninit::<[usize; 1]>::uninit().assume_init() };
     //~^ ERROR: uninitialized
 }

tests/fail/validity/uninit_integer.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at .value[0]: encountered uninitialized bytes
   --> $DIR/uninit_integer.rs:LL:CC
    |
-LL |     let _val = unsafe { std::mem::MaybeUninit::<usize>::uninit().assume_init() };
-   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+LL |     let _val = unsafe { std::mem::MaybeUninit::<[usize; 1]>::uninit().assume_init() };
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .value[0]: encountered uninitialized bytes
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/fail/validity/uninit_raw_ptr.rs

@@ -1,4 +1,7 @@
+#![allow(invalid_value)]
+
 fn main() {
-    let _val = unsafe { std::mem::MaybeUninit::<*const u8>::uninit().assume_init() };
+    // The array avoids a `Scalar` layout which detects uninit without even doing validation.
+    let _val = unsafe { std::mem::MaybeUninit::<[*const u8; 1]>::uninit().assume_init() };
     //~^ ERROR: uninitialized
 }

tests/fail/validity/uninit_raw_ptr.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
+error: Undefined Behavior: constructing invalid value at .value[0]: encountered uninitialized memory, but expected a raw pointer
   --> $DIR/uninit_raw_ptr.rs:LL:CC
    |
-LL |     let _val = unsafe { std::mem::MaybeUninit::<*const u8>::uninit().assume_init() };
-   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
+LL |     let _val = unsafe { std::mem::MaybeUninit::<[*const u8; 1]>::uninit().assume_init() };
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .value[0]: encountered uninitialized memory, but expected a raw pointer
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information