Rollup merge of #133384 - RalfJung:vector-abi-check-tests, r=jieyouxu

add a test for target-feature-ABI warnings in closures and when calling extern fn

Also update the comment regarding the inheritance of target features into closures, to make it more clear that we really shouldn't do this right now.

3 files changed, 95 insertions, 22 deletions

diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 32e9422e005..a5acd8170ab 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -576,9 +576,9 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
     // If this closure is marked `#[inline(always)]`, simply skip adding `#[target_feature]`.
     //
     // At this point, `unsafe` has already been checked and `#[target_feature]` only affects codegen.
-    // Emitting both `#[inline(always)]` and `#[target_feature]` can potentially result in an
-    // ICE, because LLVM errors when the function fails to be inlined due to a target feature
-    // mismatch.
+    // Due to LLVM limitations, emitting both `#[inline(always)]` and `#[target_feature]` is *unsound*:
+    // the function may be inlined into a caller with fewer target features. Also see
+    // <https://github.com/rust-lang/rust/issues/116573>.
     //
     // Using `#[inline(always)]` implies that this closure will most likely be inlined into
     // its parent function, which effectively inherits the features anyway. Boxing this closure
diff --git a/tests/ui/simd-abi-checks.rs b/tests/ui/simd-abi-checks.rs
index 9e3af26e9c4..c97767b2794 100644
--- a/tests/ui/simd-abi-checks.rs
+++ b/tests/ui/simd-abi-checks.rs
@@ -4,6 +4,7 @@
 
 #![feature(avx512_target_feature)]
 #![feature(portable_simd)]
+#![feature(target_feature_11, simd_ffi)]
 #![allow(improper_ctypes_definitions)]
 
 use std::arch::x86_64::*;
@@ -50,6 +51,14 @@ unsafe fn test() {
     as_f64x8(arg);
 }
 
+#[target_feature(enable = "avx")]
+unsafe fn in_closure() -> impl FnOnce() -> __m256 {
+    #[inline(always)] // this disables target-feature inheritance
+    || g()
+    //~^ WARNING this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+    //~| WARNING this was previously accepted by the compiler
+}
+
 fn main() {
     unsafe {
         f(g());
@@ -78,4 +87,24 @@ fn main() {
         //~| WARNING this was previously accepted by the compiler
         //~| WARNING this was previously accepted by the compiler
     }
+
+    unsafe {
+        in_closure()();
+    }
+
+    unsafe {
+        #[expect(improper_ctypes)]
+        extern "C" {
+            fn some_extern() -> __m256;
+        }
+        some_extern();
+        //~^ WARNING this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+        //~| WARNING this was previously accepted by the compiler
+    }
+}
+
+#[no_mangle]
+#[target_feature(enable = "avx")]
+fn some_extern() -> __m256 {
+    todo!()
 }
diff --git a/tests/ui/simd-abi-checks.stderr b/tests/ui/simd-abi-checks.stderr
index cd04cfa6e14..eb7d9e81029 100644
--- a/tests/ui/simd-abi-checks.stderr
+++ b/tests/ui/simd-abi-checks.stderr
@@ -1,5 +1,5 @@
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:55:11
+  --> $DIR/simd-abi-checks.rs:64:11
    |
 LL |         f(g());
    |           ^^^ function called here
@@ -10,7 +10,7 @@ LL |         f(g());
    = note: `#[warn(abi_unsupported_vector_types)]` on by default
 
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:55:9
+  --> $DIR/simd-abi-checks.rs:64:9
    |
 LL |         f(g());
    |         ^^^^^^ function called here
@@ -20,7 +20,7 @@ LL |         f(g());
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:63:14
+  --> $DIR/simd-abi-checks.rs:72:14
    |
 LL |         gavx(favx());
    |              ^^^^^^ function called here
@@ -30,7 +30,7 @@ LL |         gavx(favx());
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:63:9
+  --> $DIR/simd-abi-checks.rs:72:9
    |
 LL |         gavx(favx());
    |         ^^^^^^^^^^^^ function called here
@@ -40,7 +40,7 @@ LL |         gavx(favx());
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:75:19
+  --> $DIR/simd-abi-checks.rs:84:19
    |
 LL |         w(Wrapper(g()));
    |                   ^^^ function called here
@@ -50,7 +50,7 @@ LL |         w(Wrapper(g()));
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:75:9
+  --> $DIR/simd-abi-checks.rs:84:9
    |
 LL |         w(Wrapper(g()));
    |         ^^^^^^^^^^^^^^^ function called here
@@ -59,8 +59,18 @@ LL |         w(Wrapper(g()));
    = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
+warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+  --> $DIR/simd-abi-checks.rs:100:9
+   |
+LL |         some_extern();
+   |         ^^^^^^^^^^^^^ function called here
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
+   = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
+
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:26:1
+  --> $DIR/simd-abi-checks.rs:27:1
    |
 LL | unsafe extern "C" fn g() -> __m256 {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -70,7 +80,7 @@ LL | unsafe extern "C" fn g() -> __m256 {
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:20:1
+  --> $DIR/simd-abi-checks.rs:21:1
    |
 LL | unsafe extern "C" fn f(_: __m256) {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -80,7 +90,7 @@ LL | unsafe extern "C" fn f(_: __m256) {
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:14:1
+  --> $DIR/simd-abi-checks.rs:15:1
    |
 LL | unsafe extern "C" fn w(_: Wrapper) {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -89,11 +99,21 @@ LL | unsafe extern "C" fn w(_: Wrapper) {
    = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
 
-warning: 9 warnings emitted
+warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+  --> $DIR/simd-abi-checks.rs:57:8
+   |
+LL |     || g()
+   |        ^^^ function called here
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
+   = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
+
+warning: 11 warnings emitted
 
 Future incompatibility report: Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:55:11
+  --> $DIR/simd-abi-checks.rs:64:11
    |
 LL |         f(g());
    |           ^^^ function called here
@@ -105,7 +125,7 @@ LL |         f(g());
 
 Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:55:9
+  --> $DIR/simd-abi-checks.rs:64:9
    |
 LL |         f(g());
    |         ^^^^^^ function called here
@@ -117,7 +137,7 @@ LL |         f(g());
 
 Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:63:14
+  --> $DIR/simd-abi-checks.rs:72:14
    |
 LL |         gavx(favx());
    |              ^^^^^^ function called here
@@ -129,7 +149,7 @@ LL |         gavx(favx());
 
 Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:63:9
+  --> $DIR/simd-abi-checks.rs:72:9
    |
 LL |         gavx(favx());
    |         ^^^^^^^^^^^^ function called here
@@ -141,7 +161,7 @@ LL |         gavx(favx());
 
 Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:75:19
+  --> $DIR/simd-abi-checks.rs:84:19
    |
 LL |         w(Wrapper(g()));
    |                   ^^^ function called here
@@ -153,7 +173,7 @@ LL |         w(Wrapper(g()));
 
 Future breakage diagnostic:
 warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
-  --> $DIR/simd-abi-checks.rs:75:9
+  --> $DIR/simd-abi-checks.rs:84:9
    |
 LL |         w(Wrapper(g()));
    |         ^^^^^^^^^^^^^^^ function called here
@@ -164,8 +184,20 @@ LL |         w(Wrapper(g()));
    = note: `#[warn(abi_unsupported_vector_types)]` on by default
 
 Future breakage diagnostic:
+warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+  --> $DIR/simd-abi-checks.rs:100:9
+   |
+LL |         some_extern();
+   |         ^^^^^^^^^^^^^ function called here
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
+   = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
+   = note: `#[warn(abi_unsupported_vector_types)]` on by default
+
+Future breakage diagnostic:
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:26:1
+  --> $DIR/simd-abi-checks.rs:27:1
    |
 LL | unsafe extern "C" fn g() -> __m256 {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -177,7 +209,7 @@ LL | unsafe extern "C" fn g() -> __m256 {
 
 Future breakage diagnostic:
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:20:1
+  --> $DIR/simd-abi-checks.rs:21:1
    |
 LL | unsafe extern "C" fn f(_: __m256) {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -189,7 +221,7 @@ LL | unsafe extern "C" fn f(_: __m256) {
 
 Future breakage diagnostic:
 warning: this function definition uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled
-  --> $DIR/simd-abi-checks.rs:14:1
+  --> $DIR/simd-abi-checks.rs:15:1
    |
 LL | unsafe extern "C" fn w(_: Wrapper) {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function defined here
@@ -199,3 +231,15 @@ LL | unsafe extern "C" fn w(_: Wrapper) {
    = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
    = note: `#[warn(abi_unsupported_vector_types)]` on by default
 
+Future breakage diagnostic:
+warning: this function call uses a SIMD vector type that (with the chosen ABI) requires the `avx` target feature, which is not enabled in the caller
+  --> $DIR/simd-abi-checks.rs:57:8
+   |
+LL |     || g()
+   |        ^^^ function called here
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
+   = help: consider enabling it globally (`-C target-feature=+avx`) or locally (`#[target_feature(enable="avx")]`)
+   = note: `#[warn(abi_unsupported_vector_types)]` on by default
+