Attribute: do not apply vector_size to enums

clang silently ignores the attribute; GCC issues an error
diagnostic

Fixes #658

src/aro/Attribute.zig

@@ -1049,11 +1049,13 @@ fn applyTransparentUnion(attr: Attribute, p: *Parser, tok: TokenIndex, ty: Type)
 }
 
 fn applyVectorSize(attr: Attribute, p: *Parser, tok: TokenIndex, ty: *Type) !void {
-    if (!(ty.isInt() or ty.isFloat()) or !ty.isReal()) {
-        const orig_ty = try p.typeStr(ty.*);
-        ty.* = Type.invalid;
-        return p.errStr(.invalid_vec_elem_ty, tok, orig_ty);
+    const is_enum = ty.is(.@"enum");
+    if (!(ty.isInt() or ty.isFloat()) or !ty.isReal() or (is_enum and p.comp.langopts.emulate == .gcc)) {
+        try p.errStr(.invalid_vec_elem_ty, tok, try p.typeStr(ty.*));
+        return error.ParsingFailed;
     }
+    if (is_enum) return;
+
     const vec_bytes = attr.args.vector_size.bytes;
     const ty_size = ty.sizeof(p.comp).?;
     if (vec_bytes % ty_size != 0) {

test/cases/ast/vectors.c

@@ -1,6 +1,3 @@
-typedef: 'invalid'
- name: invalid1
-
 typedef: 'float'
  name: invalid2
 

test/cases/enum attributes clang.c

@@ -0,0 +1,42 @@
+//aro-args --emulate=clang
+enum E {
+   is_deprecated __attribute__((deprecated)),
+   is_deprecated_with_msg __attribute__((deprecated("I am deprecated"))),
+   is_unavailable __attribute__((unavailable)),
+   is_unavailable_with_msg  __attribute__((unavailable("I am not available"))),
+   newval,
+};
+
+void foo(void) {
+  int a = newval;
+  a = is_deprecated;
+  a = is_deprecated_with_msg;
+  a = is_unavailable;
+  a = is_unavailable_with_msg;
+}
+
+enum __attribute__((aligned(16))) Attributed {
+  Val,
+};
+_Static_assert(_Alignof(enum Attributed) == 16, "enum align");
+
+enum Trailing {
+  Foo
+} __attribute__((aligned(32)));
+_Static_assert(_Alignof(enum Trailing) == 32, "enum align");
+
+enum __attribute__((vector_size(32))) VectorSize1;
+
+enum __attribute__((vector_size(32))) VectorSize2 {
+    A
+};
+
+
+#define EXPECTED_ERRORS "enum attributes clang.c:12:7: warning: 'is_deprecated' is deprecated [-Wdeprecated-declarations]" \
+  "enum attributes clang.c:3:33: note: 'is_deprecated' has been explicitly marked deprecated here" \
+  "enum attributes clang.c:13:7: warning: 'is_deprecated_with_msg' is deprecated: I am deprecated [-Wdeprecated-declarations]" \
+  "enum attributes clang.c:4:42: note: 'is_deprecated_with_msg' has been explicitly marked deprecated here" \
+  "enum attributes clang.c:14:7: error: 'is_unavailable' is unavailable" \
+  "enum attributes clang.c:5:34: note: 'is_unavailable' has been explicitly marked unavailable here" \
+  "enum attributes clang.c:15:7: error: 'is_unavailable_with_msg' is unavailable: I am not available" \
+  "enum attributes clang.c:6:44: note: 'is_unavailable_with_msg' has been explicitly marked unavailable here" \

test/cases/enum attributes gcc.c

@@ -0,0 +1,8 @@
+//aro-args --emulate=gcc
+
+enum __attribute__((vector_size(32))) VectorSize2 {
+    A
+};
+
+#define EXPECTED_ERRORS "enum attributes gcc.c:3:21: error: invalid vector element type 'enum VectorSize2'" \
+