Auto merge of #55720 - RalfJung:const-eval-raw, r=oli-obk

Make const_eval_raw query return just an AllocId

r? @oli-obk

10 files changed, 36 insertions, 28 deletions

diff --git a/src/test/ui/consts/const-err4.rs b/src/test/ui/consts/const-err4.rs
index 0bbc254453c..129177e9a1a 100644
--- a/src/test/ui/consts/const-err4.rs
+++ b/src/test/ui/consts/const-err4.rs
@@ -16,7 +16,7 @@ union Foo {
 
 enum Bar {
     Boo = [unsafe { Foo { b: () }.a }; 4][3],
-    //~^ ERROR evaluation of constant value failed
+    //~^ ERROR it is undefined behavior to use this value
 }
 
 fn main() {
diff --git a/src/test/ui/consts/const-err4.stderr b/src/test/ui/consts/const-err4.stderr
index bb50f38062e..38a8f75a5c2 100644
--- a/src/test/ui/consts/const-err4.stderr
+++ b/src/test/ui/consts/const-err4.stderr
@@ -1,8 +1,10 @@
-error[E0080]: evaluation of constant value failed
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-err4.rs:18:11
    |
 LL |     Boo = [unsafe { Foo { b: () }.a }; 4][3],
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.rs b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.rs
index 23e1ab013ef..cc5ddb44016 100644
--- a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.rs
+++ b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.rs
@@ -37,7 +37,7 @@ fn main() {
     //~^ ERROR it is undefined behavior to use this value
 
     const I32_REF_U128_UNION: u128 = unsafe { Nonsense { int_32_ref: &3 }.uint_128 };
-    //~^ ERROR any use of this value will cause an error
+    //~^ ERROR it is undefined behavior to use this value
 
     const I32_REF_I8_UNION: i8 = unsafe { Nonsense { int_32_ref: &3 }.int_8 };
     //~^ ERROR any use of this value will cause an error
@@ -52,7 +52,7 @@ fn main() {
     //~^ ERROR it is undefined behavior to use this value
 
     const I32_REF_I128_UNION: i128 = unsafe { Nonsense { int_32_ref: &3 }.int_128 };
-    //~^ ERROR any use of this value will cause an error
+    //~^ ERROR it is undefined behavior to use this value
 
     const I32_REF_F32_UNION: f32 = unsafe { Nonsense { int_32_ref: &3 }.float_32 };
     //~^ ERROR any use of this value will cause an error
diff --git a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
index 0126743eede..786338222e3 100644
--- a/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
+++ b/src/test/ui/consts/const-eval/const-pointer-values-in-various-types.stderr
@@ -40,11 +40,13 @@ LL |     const I32_REF_U64_UNION: u64 = unsafe { Nonsense { int_32_ref: &3 }.uin
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
-error: any use of this value will cause an error
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:39:5
    |
 LL |     const I32_REF_U128_UNION: u128 = unsafe { Nonsense { int_32_ref: &3 }.uint_128 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error: any use of this value will cause an error
   --> $DIR/const-pointer-values-in-various-types.rs:42:5
@@ -78,11 +80,13 @@ LL |     const I32_REF_I64_UNION: i64 = unsafe { Nonsense { int_32_ref: &3 }.int
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
-error: any use of this value will cause an error
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/const-pointer-values-in-various-types.rs:54:5
    |
 LL |     const I32_REF_I128_UNION: i128 = unsafe { Nonsense { int_32_ref: &3 }.int_128 };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes
+   |
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error: any use of this value will cause an error
   --> $DIR/const-pointer-values-in-various-types.rs:57:5
diff --git a/src/test/ui/consts/const-eval/ub-enum.rs b/src/test/ui/consts/const-eval/ub-enum.rs
index 89b44946441..2bf85e25a21 100644
--- a/src/test/ui/consts/const-eval/ub-enum.rs
+++ b/src/test/ui/consts/const-eval/ub-enum.rs
@@ -16,12 +16,12 @@ enum Enum {
     A = 0,
 }
 union TransmuteEnum {
-    a: &'static u8,
-    out: Enum,
+    in1: &'static u8,
+    out1: Enum,
 }
 
 // A pointer is guaranteed non-null
-const BAD_ENUM: Enum = unsafe { TransmuteEnum { a: &1 }.out };
+const BAD_ENUM: Enum = unsafe { TransmuteEnum { in1: &1 }.out1 };
 //~^ ERROR is undefined behavior
 
 // (Potentially) invalid enum discriminant
@@ -48,8 +48,8 @@ const BAD_ENUM3: Enum2 = unsafe { TransmuteEnum2 { in2: &0 }.out1 };
 const BAD_ENUM4: Wrap<Enum2> = unsafe { TransmuteEnum2 { in2: &0 }.out2 };
 //~^ ERROR is undefined behavior
 
-// Undef enum discriminant. In an arry to avoid `Scalar` layout.
-const BAD_ENUM_UNDEF: [Enum2; 2] = [unsafe { TransmuteEnum2 { in3: () }.out1 }; 2];
+// Undef enum discriminant.
+const BAD_ENUM_UNDEF : Enum2 = unsafe { TransmuteEnum2 { in3: () }.out1 };
 //~^ ERROR is undefined behavior
 
 // Pointer value in an enum with a niche that is not just 0.
diff --git a/src/test/ui/consts/const-eval/ub-enum.stderr b/src/test/ui/consts/const-eval/ub-enum.stderr
index 5aae3a2f351..509faaa46f8 100644
--- a/src/test/ui/consts/const-eval/ub-enum.stderr
+++ b/src/test/ui/consts/const-eval/ub-enum.stderr
@@ -1,8 +1,8 @@
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:24:1
    |
-LL | const BAD_ENUM: Enum = unsafe { TransmuteEnum { a: &1 }.out };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected a valid enum discriminant
+LL | const BAD_ENUM: Enum = unsafe { TransmuteEnum { in1: &1 }.out1 };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered a pointer, but expected a valid enum discriminant
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
@@ -33,8 +33,8 @@ LL | const BAD_ENUM4: Wrap<Enum2> = unsafe { TransmuteEnum2 { in2: &0 }.out2 };
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-enum.rs:52:1
    |
-LL | const BAD_ENUM_UNDEF: [Enum2; 2] = [unsafe { TransmuteEnum2 { in3: () }.out1 }; 2];
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes at [0], but expected a valid enum discriminant
+LL | const BAD_ENUM_UNDEF : Enum2 = unsafe { TransmuteEnum2 { in3: () }.out1 };
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected a valid enum discriminant
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
diff --git a/src/test/ui/consts/const-eval/union-const-eval-field.rs b/src/test/ui/consts/const-eval/union-const-eval-field.rs
index c0bfbc17629..2bdad3af889 100644
--- a/src/test/ui/consts/const-eval/union-const-eval-field.rs
+++ b/src/test/ui/consts/const-eval/union-const-eval-field.rs
@@ -34,7 +34,8 @@ const fn read_field2() -> Field2 {
 }
 
 const fn read_field3() -> Field3 {
-    const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR any use of this value
+    const FIELD3: Field3 = unsafe { UNION.field3 };
+    //~^ ERROR it is undefined behavior to use this value
     FIELD3
 }
 
diff --git a/src/test/ui/consts/const-eval/union-const-eval-field.stderr b/src/test/ui/consts/const-eval/union-const-eval-field.stderr
index 565cd916ffc..ca7cf2b028c 100644
--- a/src/test/ui/consts/const-eval/union-const-eval-field.stderr
+++ b/src/test/ui/consts/const-eval/union-const-eval-field.stderr
@@ -1,10 +1,11 @@
-error: any use of this value will cause an error
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/union-const-eval-field.rs:37:5
    |
-LL |     const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR any use of this value
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
+LL |     const FIELD3: Field3 = unsafe { UNION.field3 };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes
    |
-   = note: #[deny(const_err)] on by default
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/union-ice.rs b/src/test/ui/consts/const-eval/union-ice.rs
index 0e4f1e09171..6bd63472b21 100644
--- a/src/test/ui/consts/const-eval/union-ice.rs
+++ b/src/test/ui/consts/const-eval/union-ice.rs
@@ -20,7 +20,7 @@ union DummyUnion {
 
 const UNION: DummyUnion = DummyUnion { field1: 1065353216 };
 
-const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR will cause an error
+const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR it is undefined behavior to use this value
 
 const FIELD_PATH: Struct = Struct { //~ ERROR it is undefined behavior to use this value
     a: 42,
diff --git a/src/test/ui/consts/const-eval/union-ice.stderr b/src/test/ui/consts/const-eval/union-ice.stderr
index 98c2c1472aa..7cadef24617 100644
--- a/src/test/ui/consts/const-eval/union-ice.stderr
+++ b/src/test/ui/consts/const-eval/union-ice.stderr
@@ -1,10 +1,10 @@
-error: any use of this value will cause an error
+error[E0080]: it is undefined behavior to use this value
   --> $DIR/union-ice.rs:23:1
    |
-LL | const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR will cause an error
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
+LL | const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR it is undefined behavior to use this value
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered uninitialized bytes, but expected initialized plain (non-pointer) bytes
    |
-   = note: #[deny(const_err)] on by default
+   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
 
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/union-ice.rs:25:1