Auto merge of #3506 - rust-lang:rustup-2024-04-24, r=RalfJung

Automatic Rustup

Author: bors

rust-version

@@ -1 +1 @@
-aca749eefceaed0cda19a7ec5e472fce9387bc00
+c1feb3eceef7d5f0126c309a87062cf413fe0a25

src/shims/intrinsics/simd.rs

@@ -163,7 +163,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                             }
                         }
                         Op::Numeric(name) => {
-                            this.numeric_intrinsic(name, op.to_scalar(), op.layout)?
+                            this.numeric_intrinsic(name, op.to_scalar(), op.layout, op.layout)?
                         }
                     };
                     this.write_scalar(val, &dest)?;

tests/fail/dyn-call-trait-mismatch.rs

@@ -1,3 +1,6 @@
+// Validation stops this too early.
+//@compile-flags: -Zmiri-disable-validation
+
 trait T1 {
     #[allow(dead_code)]
     fn method1(self: Box<Self>);
@@ -13,5 +16,5 @@ impl T1 for i32 {
 fn main() {
     let r = Box::new(0) as Box<dyn T1>;
     let r2: Box<dyn T2> = unsafe { std::mem::transmute(r) };
-    r2.method2(); //~ERROR: call on a pointer whose vtable does not match its type
+    r2.method2(); //~ERROR: using vtable for trait `T1` but trait `T2` was expected
 }

tests/fail/dyn-call-trait-mismatch.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: `dyn` call on a pointer whose vtable does not match its type
+error: Undefined Behavior: using vtable for trait `T1` but trait `T2` was expected
   --> $DIR/dyn-call-trait-mismatch.rs:LL:CC
    |
 LL |     r2.method2();
-   |     ^^^^^^^^^^^^ `dyn` call on a pointer whose vtable does not match its type
+   |     ^^^^^^^^^^^^ using vtable for trait `T1` but trait `T2` was expected
    |
    = 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/dyn-upcast-nop-wrong-trait.rs

@@ -0,0 +1,15 @@
+// This upcast is currently forbidden because it involves an invalid value.
+// However, if in the future we relax the validity requirements for raw pointer vtables,
+// we could consider allowing this again -- the cast itself isn't doing anything wrong,
+// only the transmutes needed to set up the testcase are wrong.
+
+use std::fmt;
+
+fn main() {
+    // vtable_mismatch_nop_cast
+    let ptr: &dyn fmt::Display = &0;
+    let ptr: *const (dyn fmt::Debug + Send + Sync) = unsafe { std::mem::transmute(ptr) }; //~ERROR: wrong trait
+    // Even though the vtable is for the wrong trait, this cast doesn't actually change the needed
+    // vtable so it should still be allowed -- if we ever allow the line above.
+    let _ptr2 = ptr as *const dyn fmt::Debug;
+}

tests/fail/dyn-upcast-nop-wrong-trait.stderr

@@ -0,0 +1,15 @@
+error: Undefined Behavior: constructing invalid value: wrong trait in wide pointer vtable: expected `std::fmt::Debug + std::marker::Send + std::marker::Sync`, but encountered `std::fmt::Display`
+  --> $DIR/dyn-upcast-nop-wrong-trait.rs:LL:CC
+   |
+LL |     let ptr: *const (dyn fmt::Debug + Send + Sync) = unsafe { std::mem::transmute(ptr) };
+   |                                                               ^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: wrong trait in wide pointer vtable: expected `std::fmt::Debug + std::marker::Send + std::marker::Sync`, but encountered `std::fmt::Display`
+   |
+   = 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
+   = note: BACKTRACE:
+   = note: inside `main` at $DIR/dyn-upcast-nop-wrong-trait.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/fail/dyn-upcast-trait-mismatch.rs

@@ -1,3 +1,6 @@
+// Validation stops this too early.
+//@compile-flags: -Zmiri-disable-validation
+
 #![feature(trait_upcasting)]
 #![allow(incomplete_features)]
 
@@ -57,7 +60,7 @@ impl Baz for i32 {
 
 fn main() {
     let baz: &dyn Baz = &1;
-    let baz_fake: &dyn Bar = unsafe { std::mem::transmute(baz) };
-    let _err = baz_fake as &dyn Foo;
-    //~^ERROR: upcast on a pointer whose vtable does not match its type
+    let baz_fake: *const dyn Bar = unsafe { std::mem::transmute(baz) };
+    let _err = baz_fake as *const dyn Foo;
+    //~^ERROR: using vtable for trait `Baz` but trait `Bar` was expected
 }

tests/fail/dyn-upcast-trait-mismatch.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: upcast on a pointer whose vtable does not match its type
+error: Undefined Behavior: using vtable for trait `Baz` but trait `Bar` was expected
   --> $DIR/dyn-upcast-trait-mismatch.rs:LL:CC
    |
-LL |     let _err = baz_fake as &dyn Foo;
-   |                ^^^^^^^^ upcast on a pointer whose vtable does not match its type
+LL |     let _err = baz_fake as *const dyn Foo;
+   |                ^^^^^^^^ using vtable for trait `Baz` but trait `Bar` was expected
    |
    = 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/intrinsics/ctlz_nonzero.rs

@@ -2,7 +2,7 @@
 
 mod rusti {
     extern "rust-intrinsic" {
-        pub fn ctlz_nonzero<T>(x: T) -> T;
+        pub fn ctlz_nonzero<T>(x: T) -> u32;
     }
 }
 

tests/fail/intrinsics/cttz_nonzero.rs

@@ -2,7 +2,7 @@
 
 mod rusti {
     extern "rust-intrinsic" {
-        pub fn cttz_nonzero<T>(x: T) -> T;
+        pub fn cttz_nonzero<T>(x: T) -> u32;
     }
 }