Merge from rustc

Author: The Miri Cronjob Bot

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

@@ -1,5 +1,5 @@
-// Validation stops this too early.
-//@compile-flags: -Zmiri-disable-validation
+// Validation and SB stop this too early.
+//@compile-flags: -Zmiri-disable-validation -Zmiri-disable-stacked-borrows
 
 trait T1 {
     #[allow(dead_code)]

tests/fail/validity/invalid_char_cast.rs

@@ -0,0 +1,21 @@
+// Make sure we find these even with many checks disabled.
+//@compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation
+#![feature(core_intrinsics)]
+#![feature(custom_mir)]
+
+use std::intrinsics::mir::*;
+
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+fn cast(ptr: *const char) -> u32 {
+    mir! {
+        {
+            RET = *ptr as u32; //~ERROR: interpreting an invalid 32-bit value as a char
+            Return()
+        }
+    }
+}
+
+pub fn main() {
+    let v = u32::MAX;
+    cast(&v as *const u32 as *const char);
+}

tests/fail/validity/invalid_char_cast.stderr

@@ -0,0 +1,20 @@
+error: Undefined Behavior: interpreting an invalid 32-bit value as a char: $HEX
+  --> $DIR/invalid_char_cast.rs:LL:CC
+   |
+LL |             RET = *ptr as u32;
+   |             ^^^^^^^^^^^^^^^^^ interpreting an invalid 32-bit value as a char: $HEX
+   |
+   = 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 `cast` at $DIR/invalid_char_cast.rs:LL:CC
+note: inside `main`
+  --> $DIR/invalid_char_cast.rs:LL:CC
+   |
+LL |     cast(&v as *const u32 as *const char);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/fail/validity/invalid_char_match.rs

@@ -0,0 +1,26 @@
+// Make sure we find these even with many checks disabled.
+//@compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation
+#![feature(core_intrinsics)]
+#![feature(custom_mir)]
+
+use std::intrinsics::mir::*;
+
+#[custom_mir(dialect = "runtime", phase = "optimized")]
+fn switch_int(ptr: *const char) {
+    mir! {
+        {
+            match *ptr { //~ERROR: interpreting an invalid 32-bit value as a char
+                '0' => ret,
+                _ => ret,
+            }
+        }
+        ret = {
+            Return()
+        }
+    }
+}
+
+pub fn main() {
+    let v = u32::MAX;
+    switch_int(&v as *const u32 as *const char);
+}

tests/fail/validity/invalid_char_match.stderr

@@ -0,0 +1,23 @@
+error: Undefined Behavior: interpreting an invalid 32-bit value as a char: $HEX
+  --> $DIR/invalid_char_match.rs:LL:CC
+   |
+LL | /             match *ptr {
+LL | |                 '0' => ret,
+LL | |                 _ => ret,
+LL | |             }
+   | |_____________^ interpreting an invalid 32-bit value as a char: $HEX
+   |
+   = 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 `switch_int` at $DIR/invalid_char_match.rs:LL:CC
+note: inside `main`
+  --> $DIR/invalid_char_match.rs:LL:CC
+   |
+LL |     switch_int(&v as *const u32 as *const char);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/fail/validity/invalid_enum_cast.rs

@@ -0,0 +1,15 @@
+// Make sure we find these even with many checks disabled.
+//@compile-flags: -Zmiri-disable-alignment-check -Zmiri-disable-stacked-borrows -Zmiri-disable-validation
+
+#[derive(Copy, Clone)]
+#[allow(unused)]
+enum E {A, B, C }
+
+fn cast(ptr: *const E) { unsafe {
+    let _val = *ptr as u32; //~ERROR: enum value has invalid tag
+}}
+
+pub fn main() {
+    let v = u32::MAX;
+    cast(&v as *const u32 as *const E);
+}

tests/fail/validity/invalid_enum_cast.stderr

@@ -0,0 +1,20 @@
+error: Undefined Behavior: enum value has invalid tag: 0xff
+  --> $DIR/invalid_enum_cast.rs:LL:CC
+   |
+LL |     let _val = *ptr as u32;
+   |                ^^^^^^^^^^^ enum value has invalid tag: 0xff
+   |
+   = 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 `cast` at $DIR/invalid_enum_cast.rs:LL:CC
+note: inside `main`
+  --> $DIR/invalid_enum_cast.rs:LL:CC
+   |
+LL |     cast(&v as *const u32 as *const E);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to 1 previous error
+

tests/pass/issues/issue-miri-3541-dyn-vtable-trait-normalization.rs

@@ -0,0 +1,40 @@
+#![feature(ptr_metadata)]
+// This test is the result of minimizing the `emplacable` crate to reproduce
+// <https://github.com/rust-lang/miri/issues/3541>.
+
+use std::{ops::FnMut, ptr::Pointee};
+
+pub type EmplacerFn<'a, T> = dyn for<'b> FnMut(<T as Pointee>::Metadata) + 'a;
+
+#[repr(transparent)]
+pub struct Emplacer<'a, T>(EmplacerFn<'a, T>)
+where
+    T: ?Sized;
+
+impl<'a, T> Emplacer<'a, T>
+where
+    T: ?Sized,
+{
+    pub unsafe fn from_fn<'b>(emplacer_fn: &'b mut EmplacerFn<'a, T>) -> &'b mut Self {
+        // This used to trigger:
+        // constructing invalid value: wrong trait in wide pointer vtable: expected
+        // `std::ops::FnMut(<[std::boxed::Box<i32>] as std::ptr::Pointee>::Metadata)`, but encountered
+        // `std::ops::FnMut<(usize,)>`.
+        unsafe { &mut *((emplacer_fn as *mut EmplacerFn<'a, T>) as *mut Self) }
+    }
+}
+
+pub fn box_new_with<T>()
+where
+    T: ?Sized,
+{
+    let emplacer_closure = &mut |_meta| {
+        unreachable!();
+    };
+
+    unsafe { Emplacer::<T>::from_fn(emplacer_closure) };
+}
+
+fn main() {
+    box_new_with::<[Box<i32>]>();
+}