Auto merge of #115374 - RalfJung:miri-fn-abi, r=oli-obk

miri function ABI check: accept repr(transparent) wrappers as compatible

17 files changed, 116 insertions, 11 deletions

diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.rs
new file mode 100644
index 00000000000..415e91b250f
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.rs
@@ -0,0 +1,16 @@
+#![feature(portable_simd)]
+
+// Some targets treat arrays and structs very differently. We would probably catch that on those
+// targets since we check the `PassMode`; here we ensure that we catch it on *all* targets
+// (in particular, on x86-64 the pass mode is `Indirect` for both of these).
+struct S(i32, i32, i32, i32);
+type A = [i32; 4];
+
+fn main() {
+    fn f(_: S) {}
+
+    // These two types have the same size but are still not compatible.
+    let g = unsafe { std::mem::transmute::<fn(S), fn(A)>(f) };
+
+    g(Default::default()) //~ ERROR: calling a function with argument of type S passing data of type [i32; 4]
+}
diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.stderr
new file mode 100644
index 00000000000..50d4228c111
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_array_vs_struct.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: calling a function with argument of type S passing data of type [i32; 4]
+  --> $DIR/abi_mismatch_array_vs_struct.rs:LL:CC
+   |
+LL |     g(Default::default())
+   |     ^^^^^^^^^^^^^^^^^^^^^ calling a function with argument of type S passing data of type [i32; 4]
+   |
+   = 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/abi_mismatch_array_vs_struct.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+
diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.rs
new file mode 100644
index 00000000000..a1fda329e8d
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.rs
@@ -0,0 +1,7 @@
+fn main() {
+    fn f(_: f32) {}
+
+    let g = unsafe { std::mem::transmute::<fn(f32), fn(i32)>(f) };
+
+    g(42) //~ ERROR: calling a function with argument of type f32 passing data of type i32
+}
diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.stderr
new file mode 100644
index 00000000000..a53126c733e
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_int_vs_float.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: calling a function with argument of type f32 passing data of type i32
+  --> $DIR/abi_mismatch_int_vs_float.rs:LL:CC
+   |
+LL |     g(42)
+   |     ^^^^^ calling a function with argument of type f32 passing data of type i32
+   |
+   = 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/abi_mismatch_int_vs_float.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr4.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_raw_pointer.rs
index f0ea5ccfe0f..f0ea5ccfe0f 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr4.rs
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_raw_pointer.rs
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr4.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_raw_pointer.stderr
index 610425658fe..6eacfeece14 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr4.stderr
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_raw_pointer.stderr
@@ -1,5 +1,5 @@
 error: Undefined Behavior: calling a function with argument of type *const [i32] passing data of type *const i32
-  --> $DIR/cast_fn_ptr4.rs:LL:CC
+  --> $DIR/abi_mismatch_raw_pointer.rs:LL:CC
    |
 LL |     g(&42 as *const i32)
    |     ^^^^^^^^^^^^^^^^^^^^ calling a function with argument of type *const [i32] passing data of type *const i32
@@ -7,7 +7,7 @@ LL |     g(&42 as *const i32)
    = 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/cast_fn_ptr4.rs:LL:CC
+   = note: inside `main` at $DIR/abi_mismatch_raw_pointer.rs:LL:CC
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
 
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr5.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_return_type.rs
index 0fdab49b94b..0fdab49b94b 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr5.rs
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_return_type.rs
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr5.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_return_type.stderr
index c4e08b58430..eedc1235773 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr5.stderr
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_return_type.stderr
@@ -1,5 +1,5 @@
 error: Undefined Behavior: calling a function with return type u32 passing return place of type ()
-  --> $DIR/cast_fn_ptr5.rs:LL:CC
+  --> $DIR/abi_mismatch_return_type.rs:LL:CC
    |
 LL |     g()
    |     ^^^ calling a function with return type u32 passing return place of type ()
@@ -7,7 +7,7 @@ LL |     g()
    = 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/cast_fn_ptr5.rs:LL:CC
+   = note: inside `main` at $DIR/abi_mismatch_return_type.rs:LL:CC
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
 
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr2.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_simple.rs
index 20384f0965b..20384f0965b 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr2.rs
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_simple.rs
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr2.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_simple.stderr
index 086712e0d13..bc500a90b77 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr2.stderr
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_simple.stderr
@@ -1,5 +1,5 @@
 error: Undefined Behavior: calling a function with argument of type (i32, i32) passing data of type i32
-  --> $DIR/cast_fn_ptr2.rs:LL:CC
+  --> $DIR/abi_mismatch_simple.rs:LL:CC
    |
 LL |     g(42)
    |     ^^^^^ calling a function with argument of type (i32, i32) passing data of type i32
@@ -7,7 +7,7 @@ LL |     g(42)
    = 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/cast_fn_ptr2.rs:LL:CC
+   = note: inside `main` at $DIR/abi_mismatch_simple.rs:LL:CC
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
 
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr3.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_few_args.rs
index 920fb51abb6..920fb51abb6 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr3.rs
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_few_args.rs
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr3.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_few_args.stderr
index 55fd7d60720..558d83bcfd2 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr3.stderr
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_few_args.stderr
@@ -1,5 +1,5 @@
 error: Undefined Behavior: calling a function with fewer arguments than it requires
-  --> $DIR/cast_fn_ptr3.rs:LL:CC
+  --> $DIR/abi_mismatch_too_few_args.rs:LL:CC
    |
 LL |     g()
    |     ^^^ calling a function with fewer arguments than it requires
@@ -7,7 +7,7 @@ LL |     g()
    = 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/cast_fn_ptr3.rs:LL:CC
+   = note: inside `main` at $DIR/abi_mismatch_too_few_args.rs:LL:CC
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
 
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr1.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_many_args.rs
index c0e96a43cc5..c0e96a43cc5 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr1.rs
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_many_args.rs
diff --git a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr1.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_many_args.stderr
index bb2a2637959..dc12073952f 100644
--- a/src/tools/miri/tests/fail/function_pointers/cast_fn_ptr1.stderr
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_too_many_args.stderr
@@ -1,5 +1,5 @@
 error: Undefined Behavior: calling a function with more arguments than it expected
-  --> $DIR/cast_fn_ptr1.rs:LL:CC
+  --> $DIR/abi_mismatch_too_many_args.rs:LL:CC
    |
 LL |     g(42)
    |     ^^^^^ calling a function with more arguments than it expected
@@ -7,7 +7,7 @@ LL |     g(42)
    = 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/cast_fn_ptr1.rs:LL:CC
+   = note: inside `main` at $DIR/abi_mismatch_too_many_args.rs:LL:CC
 
 note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
 
diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.rs b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.rs
new file mode 100644
index 00000000000..80f357b61ba
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.rs
@@ -0,0 +1,11 @@
+#![feature(portable_simd)]
+use std::simd;
+
+fn main() {
+    fn f(_: simd::u32x8) {}
+
+    // These two vector types have the same size but are still not compatible.
+    let g = unsafe { std::mem::transmute::<fn(simd::u32x8), fn(simd::u64x4)>(f) };
+
+    g(Default::default()) //~ ERROR: calling a function with argument of type std::simd::Simd<u32, 8> passing data of type std::simd::Simd<u64, 4>
+}
diff --git a/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.stderr b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.stderr
new file mode 100644
index 00000000000..7dcca1e85b8
--- /dev/null
+++ b/src/tools/miri/tests/fail/function_pointers/abi_mismatch_vector.stderr
@@ -0,0 +1,15 @@
+error: Undefined Behavior: calling a function with argument of type std::simd::Simd<u32, 8> passing data of type std::simd::Simd<u64, 4>
+  --> $DIR/abi_mismatch_vector.rs:LL:CC
+   |
+LL |     g(Default::default())
+   |     ^^^^^^^^^^^^^^^^^^^^^ calling a function with argument of type std::simd::Simd<u32, 8> passing data of type std::simd::Simd<u64, 4>
+   |
+   = 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/abi_mismatch_vector.rs:LL:CC
+
+note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace
+
+error: aborting due to previous error
+
diff --git a/src/tools/miri/tests/pass/function_calls/abi_compat.rs b/src/tools/miri/tests/pass/function_calls/abi_compat.rs
index 67b87b46bd9..0786450f751 100644
--- a/src/tools/miri/tests/pass/function_calls/abi_compat.rs
+++ b/src/tools/miri/tests/pass/function_calls/abi_compat.rs
@@ -1,5 +1,7 @@
+#![feature(portable_simd)]
 use std::num;
 use std::mem;
+use std::simd;
 
 fn test_abi_compat<T, U>(t: T, u: U) {
     fn id<T>(x: T) -> T { x }
@@ -15,6 +17,23 @@ fn test_abi_compat<T, U>(t: T, u: U) {
     drop(f(t));
 }
 
+/// Ensure that `T` is compatible with various repr(transparent) wrappers around `T`.
+fn test_abi_newtype<T: Copy>(t: T) {
+    #[repr(transparent)]
+    struct Wrapper1<T>(T);
+    #[repr(transparent)]
+    struct Wrapper2<T>(T, ());
+    #[repr(transparent)]
+    struct Wrapper2a<T>((), T);
+    #[repr(transparent)]
+    struct Wrapper3<T>(T, [u8; 0]);
+
+    test_abi_compat(t, Wrapper1(t));
+    test_abi_compat(t, Wrapper2(t, ()));
+    test_abi_compat(t, Wrapper2a((), t));
+    test_abi_compat(t, Wrapper3(t, []));
+}
+
 fn main() {
     test_abi_compat(0u32, 'x');
     test_abi_compat(&0u32, &([true; 4], [0u32; 0]));
@@ -22,6 +41,13 @@ fn main() {
     test_abi_compat(42u32, num::NonZeroU32::new(1).unwrap());
     test_abi_compat(0u32, Some(num::NonZeroU32::new(1).unwrap()));
     test_abi_compat(0u32, 0i32);
-    // Note that `bool` and `u8` are *not* compatible!
+    test_abi_compat(simd::u32x8::splat(1), simd::i32x8::splat(1));
+    // Note that `bool` and `u8` are *not* compatible, at least on x86-64!
     // One of them has `arg_ext: Zext`, the other does not.
+
+    test_abi_newtype(0u32);
+    test_abi_newtype(0f32);
+    test_abi_newtype((0u32, 1u32, 2u32));
+    test_abi_newtype([0u32, 1u32, 2u32]);
+    test_abi_newtype([0i32; 0]);
 }