Using the TargetSpecificAttr instead of InheritableAttr

Author: BeMg

clang/include/clang/Basic/Attr.td

@@ -3263,7 +3263,7 @@ def Target : InheritableAttr {
   }];
 }
 
-def TargetVersion : InheritableAttr {
+def TargetVersion : DeclOrTypeAttr, TargetSpecificAttr<TargetArch<!listconcat(TargetAArch64.Arches, TargetRISCV.Arches)>> {
   let Spellings = [GCC<"target_version">];
   let Args = [StringArgument<"NamesStr">];
   let Subjects = SubjectList<[Function], ErrorDiag>;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -3282,8 +3282,6 @@ def warn_unsupported_target_attribute
               "attribute string; '%select{target|target_clones|target_version}3' "
               "attribute ignored">,
       InGroup<IgnoredAttributes>;
-def err_target_version_unsupported
-    : Error<"target_version attribute is not supported on this target">;
 def err_attribute_unsupported
     : Error<"%0 attribute is not supported on targets missing %1;"
             " specify an appropriate -march= or -mcpu=">;

clang/lib/Sema/SemaDeclAttr.cpp

@@ -3041,10 +3041,6 @@ bool Sema::checkTargetVersionAttr(SourceLocation LiteralLoc, Decl *D,
   enum SecondParam { None };
   enum ThirdParam { Target, TargetClones, TargetVersion };
 
-  if (!Context.getTargetInfo().getTriple().isRISCV() &&
-      !Context.getTargetInfo().getTriple().isAArch64())
-    return Diag(LiteralLoc, diag::err_target_version_unsupported);
-
   llvm::SmallVector<StringRef, 8> Features;
   if (Context.getTargetInfo().getTriple().isRISCV()) {
     llvm::SmallVector<StringRef, 8> AttrStrs;

clang/test/Sema/attr-target-version-unsupported.c

@@ -1,4 +1,4 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-unknown  -fsyntax-only -verify %s
 
-//expected-error@+1 {{target_version attribute is not supported on this target}}
+//expected-warning@+1 {{unknown attribute 'target_version' ignored}}
 int __attribute__((target_version("aes"))) foo(void) { return 3; }