Add FunctionDecl::isVariadic() to match BlockDecl::isVariadic() and ObjCMethodDecl::isVariadic().

Do some minor refactoring along the way.

llvm-svn: 102635

clang/include/clang/AST/Decl.h

@@ -1138,6 +1138,9 @@ public:
   void setBody(Stmt *B);
   void setLazyBody(uint64_t Offset) { Body = Offset; }
 
+  /// Whether this function is variadic.
+  bool isVariadic() const;
+
   /// Whether this function is marked as virtual explicitly.
   bool isVirtualAsWritten() const { return IsVirtualAsWritten; }
   void setVirtualAsWritten(bool V) { IsVirtualAsWritten = V; }

clang/lib/AST/Decl.cpp

@@ -906,6 +906,12 @@ void FunctionDecl::getNameForDiagnostic(std::string &S,
     
 }
 
+bool FunctionDecl::isVariadic() const {
+  if (const FunctionProtoType *FT = getType()->getAs<FunctionProtoType>())
+    return FT->isVariadic();
+  return false;
+}
+
 Stmt *FunctionDecl::getBody(const FunctionDecl *&Definition) const {
   for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I) {
     if (I->Body) {

clang/lib/Sema/SemaChecking.cpp

@@ -511,15 +511,10 @@ bool Sema::SemaBuiltinVAStart(CallExpr *TheCall) {
   bool isVariadic;
   if (CurBlock)
     isVariadic = CurBlock->isVariadic;
-  else if (getCurFunctionDecl()) {
-    if (FunctionProtoType* FTP =
-            dyn_cast<FunctionProtoType>(getCurFunctionDecl()->getType()))
-      isVariadic = FTP->isVariadic();
-    else
-      isVariadic = false;
-  } else {
+  else if (FunctionDecl *FD = getCurFunctionDecl())
+    isVariadic = FD->isVariadic();
+  else
     isVariadic = getCurMethodDecl()->isVariadic();
-  }
 
   if (!isVariadic) {
     Diag(Fn->getLocStart(), diag::err_va_start_used_in_non_variadic_function);