Catch incorrect uses of SIMD vectors

Author: JohnTitor

compiler/rustc_typeck/src/collect.rs

@@ -2500,8 +2500,9 @@ fn simd_ffi_feature_check(
     target: &str,
     simd_width: u64,
     simd_elem_width: u64,
-    feature: String,
+    feature: Option<String>,
 ) -> Result<(), Option<&'static str>> {
+    let feature = feature.unwrap_or_default();
     match target {
         t if t.contains("x86") => {
             // FIXME: this needs to be architecture dependent and
@@ -2527,7 +2528,7 @@ fn simd_ffi_feature_check(
                 32 if feature.contains("avx") => Ok(()),
                 32 => Err(Some("avx")),
                 64 if feature.contains("avx512") => Ok(()),
-                64 => Err(Some("acx512")),
+                64 => Err(Some("avx512")),
                 _ => Err(None),
             }
         }
@@ -2637,15 +2638,31 @@ fn simd_ffi_check<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ast_ty: &hir::Ty<'_>,
     let simd_elem_width = simd_len / simd_size;
     let target: &str = &tcx.sess.target.arch;
 
+    let type_str = tcx
+        .sess
+        .source_map()
+        .span_to_snippet(ast_ty.span)
+        .map_or_else(|_| String::new(), |s| format!("{}", s));
+
+    if features.is_empty() {
+        // Should **NOT** be `Ok()`.
+        let f = simd_ffi_feature_check(target, simd_len, simd_elem_width, None).unwrap_err();
+        let msg = if let Some(f) = f {
+            format!(
+                "use of SIMD type `{}` in FFI requires `#[target_feature(enable = \"{}\")]`",
+                type_str, f,
+            )
+        } else {
+            format!("use of SIMD type `{}` in FFI not supported by any target features", type_str)
+        };
+
+        tcx.sess.struct_span_err(ast_ty.span, &msg).emit();
+    }
+
     for f in features {
         if let Err(v) =
-            simd_ffi_feature_check(target, simd_len, simd_elem_width, f.to_ident_string())
+            simd_ffi_feature_check(target, simd_len, simd_elem_width, Some(f.to_ident_string()))
         {
-            let type_str = tcx
-                .sess
-                .source_map()
-                .span_to_snippet(ast_ty.span)
-                .map_or_else(|_| String::new(), |s| format!("{}", s));
             let msg = if let Some(f) = v {
                 format!(
                     "use of SIMD type `{}` in FFI requires `#[target_feature(enable = \"{}\")]`",

src/test/ui/rfcs/rfc-2574-simd-ffi/simd-ffi-x86.rs

@@ -1,3 +1,4 @@
+// only-x86
 // only-x86_64
 
 #![feature(repr_simd)]
@@ -6,6 +7,15 @@
 #![allow(non_camel_case_types, improper_ctypes)]
 #![cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 
+#[repr(simd)]
+struct v128(i128);
+
+#[repr(simd)]
+struct v256(i128, i128);
+
+#[repr(simd)]
+struct v512(i128, i128, i128, i128);
+
 #[repr(simd)]
 struct v1024(i128, i128, i128, i128, i128, i128, i128, i128);
 
@@ -38,22 +48,13 @@ extern {
     #[target_feature(enable = "avx512f")]
     fn quux3(x: v256);
 
-    fn quuux_fail(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512f")]`
+    fn quuux_fail(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
     #[target_feature(enable = "sse")]
-    fn quuux_fail2(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512f")]`
+    fn quuux_fail2(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
     #[target_feature(enable = "avx2")]
-    fn quuux_fail3(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512f")]`
+    fn quuux_fail3(x: v512); //~ ERROR use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
     #[target_feature(enable = "avx512f")]
     fn quuux(x: v512);
 }
 
 fn main() {}
-
-#[repr(simd)]
-struct v128(i128);
-
-#[repr(simd)]
-struct v256(i128, i128);
-
-#[repr(simd)]
-struct v512(i128, i128, i128, i128);

src/test/ui/rfcs/rfc-2574-simd-ffi/simd-ffi-x86.stderr

@@ -1,20 +1,56 @@
+error: use of SIMD type `v1024` in FFI not supported by any target features
+  --> $DIR/simd-ffi-x86.rs:13:15
+   |
+LL |     fn foo(x: v1024);
+   |               ^^^^^
+
+error: use of SIMD type `v1024` in FFI not supported by any target features
+  --> $DIR/simd-ffi-x86.rs:14:23
+   |
+LL |     fn bar(x: i32, y: v1024);
+   |                       ^^^^^
+
+error: use of SIMD type `v1024` in FFI not supported by any target features
+  --> $DIR/simd-ffi-x86.rs:15:23
+   |
+LL |     fn baz(x: i32) -> v1024;
+   |                       ^^^^^
+
+error: use of SIMD type `v128` in FFI requires `#[target_feature(enable = "sse")]`
+  --> $DIR/simd-ffi-x86.rs:17:20
+   |
+LL |     fn qux_fail(x: v128);
+   |                    ^^^^
+
+error: use of SIMD type `v256` in FFI requires `#[target_feature(enable = "avx")]`
+  --> $DIR/simd-ffi-x86.rs:31:21
+   |
+LL |     fn quux_fail(x: v256);
+   |                     ^^^^
+
 error: use of SIMD type `v256` in FFI requires `#[target_feature(enable = "avx")]`
   --> $DIR/simd-ffi-x86.rs:33:22
    |
 LL |     fn quux_fail2(x: v256);
    |                      ^^^^
 
-error: use of SIMD type `v512` in FFI requires `#[target_feature(enable = "acx512")]`
+error: use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
+  --> $DIR/simd-ffi-x86.rs:41:22
+   |
+LL |     fn quuux_fail(x: v512);
+   |                      ^^^^
+
+error: use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
   --> $DIR/simd-ffi-x86.rs:43:23
    |
 LL |     fn quuux_fail2(x: v512);
    |                       ^^^^
 
-error: use of SIMD type `v512` in FFI requires `#[target_feature(enable = "acx512")]`
+error: use of SIMD type `v512` in FFI requires `#[target_feature(enable = "avx512")]`
   --> $DIR/simd-ffi-x86.rs:45:23
    |
 LL |     fn quuux_fail3(x: v512);
    |                       ^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to 9 previous errors