[Clang][Sema] Emit diagnostic for __builtin_vectorelements(<SVEType>) when SVE is not available.

As is done for other targets, I've moved the target type checking code
into SemaARM and migrated existing uses.

Fixes #155736

Author: paulwalker-arm

clang/include/clang/Sema/SemaARM.h

@@ -96,6 +96,9 @@ class SemaARM : public SemaBase {
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
+  bool checkSVETypeSupport(QualType Ty, SourceLocation Loc,
+                           const FunctionDecl *FD,
+                           const llvm::StringMap<bool> &FeatureMap);
 };
 
 SemaARM::ArmStreamingType getArmStreamingFnType(const FunctionDecl *FD);

clang/lib/Sema/Sema.cpp

@@ -2254,16 +2254,10 @@ void Sema::checkTypeSupport(QualType Ty, SourceLocation Loc, ValueDecl *D) {
     }
 
     // Don't allow SVE types in functions without a SVE target.
-    if (Ty->isSVESizelessBuiltinType() && FD && !FD->getType().isNull()) {
+    if (Ty->isSVESizelessBuiltinType() && FD) {
       llvm::StringMap<bool> CallerFeatureMap;
       Context.getFunctionFeatureMap(CallerFeatureMap, FD);
-      if (!Builtin::evaluateRequiredTargetFeatures("sve", CallerFeatureMap)) {
-        if (!Builtin::evaluateRequiredTargetFeatures("sme", CallerFeatureMap))
-          Diag(Loc, diag::err_sve_vector_in_non_sve_target) << Ty;
-        else if (!IsArmStreamingFunction(FD,
-                                         /*IncludeLocallyStreaming=*/true))
-          Diag(Loc, diag::err_sve_vector_in_non_streaming_function) << Ty;
-      }
+      ARM().checkSVETypeSupport(Ty, Loc, FD, CallerFeatureMap);
     }
 
     if (auto *VT = Ty->getAs<VectorType>();

clang/lib/Sema/SemaARM.cpp

@@ -1685,4 +1685,24 @@ bool SemaARM::checkTargetClonesAttr(
   return false;
 }
 
+bool SemaARM::checkSVETypeSupport(QualType Ty, SourceLocation Loc,
+                                  const FunctionDecl *FD,
+                                  const llvm::StringMap<bool> &FeatureMap) {
+  if (!Ty->isSVESizelessBuiltinType())
+    return false;
+
+  if (FeatureMap.lookup("sve"))
+    return false;
+
+  // No SVE environment available.
+  if (!FeatureMap.lookup("sme"))
+    return Diag(Loc, diag::err_sve_vector_in_non_sve_target) << Ty;
+
+  // SVE environment only available to streaming functions.
+  if (FD && !FD->getType().isNull() &&
+      !IsArmStreamingFunction(FD, /*IncludeLocallyStreaming=*/true))
+    return Diag(Loc, diag::err_sve_vector_in_non_streaming_function) << Ty;
+
+  return false;
+}
 } // namespace clang

clang/lib/Sema/SemaDecl.cpp

@@ -9125,20 +9125,10 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
     const FunctionDecl *FD = cast<FunctionDecl>(CurContext);
     llvm::StringMap<bool> CallerFeatureMap;
     Context.getFunctionFeatureMap(CallerFeatureMap, FD);
-
-    if (!Builtin::evaluateRequiredTargetFeatures("sve", CallerFeatureMap)) {
-      if (!Builtin::evaluateRequiredTargetFeatures("sme", CallerFeatureMap)) {
-        Diag(NewVD->getLocation(), diag::err_sve_vector_in_non_sve_target) << T;
-        NewVD->setInvalidDecl();
-        return;
-      } else if (!IsArmStreamingFunction(FD,
-                                         /*IncludeLocallyStreaming=*/true)) {
-        Diag(NewVD->getLocation(),
-             diag::err_sve_vector_in_non_streaming_function)
-            << T;
-        NewVD->setInvalidDecl();
-        return;
-      }
+    if (ARM().checkSVETypeSupport(T, NewVD->getLocation(), FD,
+                                  CallerFeatureMap)) {
+      NewVD->setInvalidDecl();
+      return;
     }
   }
 

clang/lib/Sema/SemaExpr.cpp

@@ -4189,6 +4189,14 @@ static bool CheckVectorElementsTraitOperandType(Sema &S, QualType T,
            << ""
            << "__builtin_vectorelements" << T << ArgRange;
 
+  if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext)) {
+    if (T->isSVESizelessBuiltinType()) {
+      llvm::StringMap<bool> CallerFeatureMap;
+      S.Context.getFunctionFeatureMap(CallerFeatureMap, FD);
+      return S.ARM().checkSVETypeSupport(T, Loc, FD, CallerFeatureMap);
+    }
+  }
+
   return false;
 }