Attribute tablegen now understands that attribute arguments can be optional. This allows for automated checking of the number of arguments expected vs number of arguments given for attributes. Greatly reduces the amount of manual checking required.

llvm-svn: 190368

3 files changed, 52 insertions, 228 deletions

diff --git a/clang/lib/Sema/AttributeList.cpp b/clang/lib/Sema/AttributeList.cpp
index 451b01c2ec1..8755a501c95 100644
--- a/clang/lib/Sema/AttributeList.cpp
+++ b/clang/lib/Sema/AttributeList.cpp
@@ -145,3 +145,28 @@ unsigned AttributeList::getAttributeSpellingListIndex() const {
 
 }
 
+struct ParsedAttrInfo {
+  unsigned NumArgs : 4;
+  unsigned OptArgs : 4;
+  unsigned HasCustomParsing : 1;
+};
+
+namespace {
+  #include "clang/Sema/AttrParsedAttrImpl.inc"
+}
+
+const ParsedAttrInfo& getInfo(const AttributeList& A) {
+  return AttrInfoMap[A.getKind()];
+}
+
+unsigned AttributeList::getMinArgs() const {
+  return getInfo(*this).NumArgs;
+}
+
+unsigned AttributeList::getMaxArgs() const {
+  return getMinArgs() + getInfo(*this).OptArgs;
+}
+
+bool AttributeList::hasCustomParsing() const {
+  return getInfo(*this).HasCustomParsing;
+}
diff --git a/clang/lib/Sema/CMakeLists.txt b/clang/lib/Sema/CMakeLists.txt
index 836d1259785..5e0914086c2 100644
--- a/clang/lib/Sema/CMakeLists.txt
+++ b/clang/lib/Sema/CMakeLists.txt
@@ -60,6 +60,7 @@ add_dependencies(clangSema
   ClangAttrList
   ClangAttrParsedAttrList
   ClangAttrParsedAttrKinds
+  ClangAttrParsedAttrImpl
   ClangAttrSpellingListIndex
   ClangAttrTemplateInstantiate
   ClangCommentNodes
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 0a6cee900b4..0a351279807 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -497,9 +497,6 @@ enum ThreadAttributeDeclKind {
 
 static bool checkGuardedVarAttrCommon(Sema &S, Decl *D,
                                       const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return false;
-
   // D must be either a member field or global (potentially shared) variable.
   if (!mayBeSharedVariable(D)) {
     S.Diag(Attr.getLoc(), diag::warn_thread_attribute_wrong_decl_type)
@@ -535,9 +532,6 @@ static void handlePtGuardedVarAttr(Sema &S, Decl *D,
 static bool checkGuardedByAttrCommon(Sema &S, Decl *D,
                                      const AttributeList &Attr,
                                      Expr* &Arg) {
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return false;
-
   // D must be either a member field or global (potentially shared) variable.
   if (!mayBeSharedVariable(D)) {
     S.Diag(Attr.getLoc(), diag::warn_thread_attribute_wrong_decl_type)
@@ -580,9 +574,6 @@ static void handlePtGuardedByAttr(Sema &S, Decl *D,
 
 static bool checkLockableAttrCommon(Sema &S, Decl *D,
                                     const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return false;
-
   // FIXME: Lockable structs for C code.
   if (!isa<RecordDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_thread_attribute_wrong_decl_type)
@@ -612,9 +603,6 @@ static void handleScopedLockableAttr(Sema &S, Decl *D,
 
 static void handleNoThreadSafetyAnalysis(Sema &S, Decl *D,
                                          const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_thread_attribute_wrong_decl_type)
       << Attr.getName() << ThreadExpectedFunctionOrMethod;
@@ -627,9 +615,6 @@ static void handleNoThreadSafetyAnalysis(Sema &S, Decl *D,
 
 static void handleNoSanitizeAddressAttr(Sema &S, Decl *D,
                                       const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunctionOrMethod;
@@ -643,9 +628,6 @@ static void handleNoSanitizeAddressAttr(Sema &S, Decl *D,
 
 static void handleNoSanitizeMemory(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunctionOrMethod;
@@ -658,9 +640,6 @@ static void handleNoSanitizeMemory(Sema &S, Decl *D,
 
 static void handleNoSanitizeThread(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunctionOrMethod;
@@ -922,9 +901,6 @@ static void handleUnlockFunAttr(Sema &S, Decl *D,
 
 static void handleLockReturnedAttr(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_thread_attribute_wrong_decl_type)
       << Attr.getName() << ThreadExpectedFunctionOrMethod;
@@ -968,9 +944,6 @@ static void handleLocksExcludedAttr(Sema &S, Decl *D,
 }
 
 static void handleConsumableAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   ConsumableAttr::ConsumedState DefaultState;
 
   if (Attr.isArgIdent(0)) {
@@ -1022,8 +995,6 @@ static bool checkForConsumableClass(Sema &S, const CXXMethodDecl *MD,
 }
 
 static void handleConsumesAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0)) return;
-
   if (!isa<CXXMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type) <<
       Attr.getName() << ExpectedMethod;
@@ -1040,8 +1011,6 @@ static void handleConsumesAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleCallableWhenUnconsumedAttr(Sema &S, Decl *D,
                                              const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0)) return;
-
   if (!isa<CXXMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type) <<
       Attr.getName() << ExpectedMethod;
@@ -1058,8 +1027,6 @@ static void handleCallableWhenUnconsumedAttr(Sema &S, Decl *D,
 
 static void handleTestsConsumedAttr(Sema &S, Decl *D,
                                     const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0)) return;
-
   if (!isa<CXXMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type) <<
       Attr.getName() << ExpectedMethod;
@@ -1076,8 +1043,6 @@ static void handleTestsConsumedAttr(Sema &S, Decl *D,
 
 static void handleTestsUnconsumedAttr(Sema &S, Decl *D,
                                       const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0)) return;
-
   if (!isa<CXXMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type) <<
       Attr.getName() << ExpectedMethod;
@@ -1094,8 +1059,6 @@ static void handleTestsUnconsumedAttr(Sema &S, Decl *D,
 
 static void handleReturnTypestateAttr(Sema &S, Decl *D,
                                       const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 1)) return;
-  
   ReturnTypestateAttr::ConsumedState ReturnState;
   
   if (Attr.isArgIdent(0)) {
@@ -1165,10 +1128,6 @@ static void handleExtVectorTypeAttr(Sema &S, Scope *scope, Decl *D,
 }
 
 static void handlePackedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (TagDecl *TD = dyn_cast<TagDecl>(D))
     TD->addAttr(::new (S.Context) PackedAttr(Attr.getRange(), S.Context));
   else if (FieldDecl *FD = dyn_cast<FieldDecl>(D)) {
@@ -1197,10 +1156,6 @@ static void handleMsStructAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleIBAction(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   // The IBAction attributes only apply to instance methods.
   if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
     if (MD->isInstanceMethod()) {
@@ -1240,10 +1195,6 @@ static bool checkIBOutletCommon(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleIBOutlet(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-  
   if (!checkIBOutletCommon(S, D, Attr))
     return;
 
@@ -1620,10 +1571,6 @@ static void handleWeakRefAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleAliasAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   StringLiteral *Str = 0;
   if (Attr.isArgExpr(0))
     Str = dyn_cast<StringLiteral>(Attr.getArgAsExpr(0)->IgnoreParenCasts());
@@ -1647,10 +1594,6 @@ static void handleAliasAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleMinSizeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D) && !isa<ObjCMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunctionOrMethod;
@@ -1663,10 +1606,6 @@ static void handleMinSizeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleColdAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -1684,10 +1623,6 @@ static void handleColdAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleHotAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -1705,10 +1640,6 @@ static void handleHotAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleNakedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -1722,10 +1653,6 @@ static void handleNakedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleAlwaysInlineAttr(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -1739,10 +1666,6 @@ static void handleAlwaysInlineAttr(Sema &S, Decl *D,
 
 static void handleTLSModelAttr(Sema &S, Decl *D,
                                const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   Expr *Arg = Attr.getArgAsExpr(0);
   Arg = Arg->IgnoreParenCasts();
   StringLiteral *Str = dyn_cast<StringLiteral>(Arg);
@@ -1774,10 +1697,6 @@ static void handleTLSModelAttr(Sema &S, Decl *D,
 }
 
 static void handleMallocAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     QualType RetTy = FD->getResultType();
     if (RetTy->isAnyPointerType() || RetTy->isBlockPointerType()) {
@@ -1792,10 +1711,6 @@ static void handleMallocAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleMayAliasAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   D->addAttr(::new (S.Context)
              MayAliasAttr(Attr.getRange(), S.Context,
                           Attr.getAttributeSpellingListIndex()));
@@ -1856,10 +1771,6 @@ static void handleAnalyzerNoReturnAttr(Sema &S, Decl *D,
   
   // The checking path for 'noreturn' and 'analyzer_noreturn' are different
   // because 'analyzer_noreturn' does not impact the type.
-  
-  if(!checkAttributeNumArgs(S, Attr, 0))
-      return;
-  
   if (!isFunctionOrMethod(D) && !isa<BlockDecl>(D)) {
     ValueDecl *VD = dyn_cast<ValueDecl>(D);
     if (VD == 0 || (!VD->getType()->isBlockPointerType()
@@ -1979,10 +1890,6 @@ static void handleDependencyAttr(Sema &S, Scope *Scope, Decl *D,
 }
 
 static void handleUnusedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<VarDecl>(D) && !isa<ObjCIvarDecl>(D) && !isFunctionOrMethod(D) &&
       !isa<TypeDecl>(D) && !isa<LabelDecl>(D) && !isa<FieldDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
@@ -1997,10 +1904,6 @@ static void handleUnusedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleReturnsTwiceAttr(Sema &S, Decl *D,
                                    const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -2013,10 +1916,6 @@ static void handleReturnsTwiceAttr(Sema &S, Decl *D,
 }
 
 static void handleUsedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
     if (VD->hasLocalStorage()) {
       S.Diag(Attr.getLoc(), diag::warn_attribute_ignored) << "used";
@@ -2125,9 +2024,6 @@ static void handleAttrWithMessage(Sema &S, Decl *D,
 
 static void handleArcWeakrefUnavailableAttr(Sema &S, Decl *D, 
                                             const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-  
   D->addAttr(::new (S.Context)
              ArcWeakrefUnavailableAttr(Attr.getRange(), S.Context,
                                        Attr.getAttributeSpellingListIndex()));
@@ -2141,9 +2037,6 @@ static void handleObjCRootClassAttr(Sema &S, Decl *D,
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-  
   D->addAttr(::new (S.Context)
              ObjCRootClassAttr(Attr.getRange(), S.Context,
                                Attr.getAttributeSpellingListIndex()));
@@ -2156,9 +2049,6 @@ static void handleObjCRequiresPropertyDefsAttr(Sema &S, Decl *D,
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-  
   D->addAttr(::new (S.Context)
              ObjCRequiresPropertyDefsAttr(Attr.getRange(), S.Context,
                                           Attr.getAttributeSpellingListIndex()));
@@ -2434,10 +2324,6 @@ static void handleVisibilityAttr(Sema &S, Decl *D, const AttributeList &Attr,
     return;
   }
 
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   // Check that the argument is a string literal.
   StringLiteral *Str = 0;
   if (Attr.isArgExpr(0))
@@ -2500,9 +2386,6 @@ static void handleObjCMethodFamilyAttr(Sema &S, Decl *decl,
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   IdentifierLoc *IL = Attr.getArgAsIdent(0);
 
   StringRef param = IL->Ident->getName();
@@ -2540,9 +2423,6 @@ static void handleObjCMethodFamilyAttr(Sema &S, Decl *decl,
 
 static void handleObjCExceptionAttr(Sema &S, Decl *D,
                                     const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   ObjCInterfaceDecl *OCI = dyn_cast<ObjCInterfaceDecl>(D);
   if (OCI == 0) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
@@ -2556,8 +2436,6 @@ static void handleObjCExceptionAttr(Sema &S, Decl *D,
 }
 
 static void handleObjCNSObject(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
   if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D)) {
     QualType T = TD->getUnderlyingType();
     if (!T->isCARCBridgableType()) {
@@ -2588,9 +2466,6 @@ static void handleObjCNSObject(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void
 handleOverloadableAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::err_attribute_overloadable_not_function);
     return;
@@ -2607,9 +2482,6 @@ static void handleBlocksAttr(Sema &S, Decl *D, const AttributeList &Attr) {
       << Attr.getName() << 1 << AANT_ArgumentIdentifier;
     return;
   }
-  
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
 
   IdentifierInfo *II = Attr.getArgAsIdent(0)->Ident;
   BlocksAttr::BlockType type;
@@ -2723,10 +2595,6 @@ static void handleSentinelAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleWarnUnusedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (RecordDecl *RD = dyn_cast<RecordDecl>(D))
     RD->addAttr(::new (S.Context) WarnUnusedAttr(Attr.getRange(), S.Context));
   else
@@ -2734,10 +2602,6 @@ static void handleWarnUnusedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleWarnUnusedResult(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isFunction(D) && !isa<ObjCMethodDecl>(D) && !isa<CXXRecordDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunctionMethodOrClass;
@@ -2762,10 +2626,6 @@ static void handleWarnUnusedResult(Sema &S, Decl *D, const AttributeList &Attr)
 }
 
 static void handleWeakAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) {
     if (isa<CXXRecordDecl>(D)) {
       D->addAttr(::new (S.Context) WeakAttr(Attr.getRange(), S.Context));
@@ -2784,11 +2644,6 @@ static void handleWeakAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleWeakImportAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
-
   // weak_import only applies to variable & function declarations.
   bool isDef = false;
   if (!D->canBeWeakImported(isDef)) {
@@ -2814,12 +2669,6 @@ static void handleWeakImportAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 // Handles reqd_work_group_size and work_group_size_hint.
 static void handleWorkGroupSize(Sema &S, Decl *D,
                                 const AttributeList &Attr) {
-  assert(Attr.getKind() == AttributeList::AT_ReqdWorkGroupSize 
-      || Attr.getKind() == AttributeList::AT_WorkGroupSizeHint);
-
-  // Attribute has 3 arguments.
-  if (!checkAttributeNumArgs(S, Attr, 3)) return;
-
   unsigned WGSize[3];
   for (unsigned i = 0; i < 3; ++i) {
     Expr *E = Attr.getArgAsExpr(i);
@@ -2918,10 +2767,6 @@ SectionAttr *Sema::mergeSectionAttr(Decl *D, SourceRange Range,
 }
 
 static void handleSectionAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // Attribute has no arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   // Make sure that there is a string literal as the sections's single
   // argument.
   Expr *ArgExpr = Attr.getArgAsExpr(0);
@@ -2955,9 +2800,6 @@ static void handleSectionAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 
 static void handleNothrowAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-  
   if (NoThrowAttr *Existing = D->getAttr<NoThrowAttr>()) {
     if (Existing->getLocation().isInvalid())
       Existing->setRange(Attr.getRange());
@@ -2969,9 +2811,6 @@ static void handleNothrowAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleConstAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (ConstAttr *Existing = D->getAttr<ConstAttr>()) {
    if (Existing->getLocation().isInvalid())
      Existing->setRange(Attr.getRange());
@@ -2983,10 +2822,6 @@ static void handleConstAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handlePureAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   D->addAttr(::new (S.Context)
              PureAttr(Attr.getRange(), S.Context,
                       Attr.getAttributeSpellingListIndex()));
@@ -2999,9 +2834,6 @@ static void handleCleanupAttr(Sema &S, Decl *D, const AttributeList &Attr) {
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   VarDecl *VD = dyn_cast<VarDecl>(D);
 
   if (!VD || !VD->hasLocalStorage()) {
@@ -3054,9 +2886,6 @@ static void handleCleanupAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 /// Handle __attribute__((format_arg((idx)))) attribute based on
 /// http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
 static void handleFormatArgAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   if (!isFunctionOrMethod(D) || !hasFunctionProto(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -3156,10 +2985,6 @@ static void handleInitPriorityAttr(Sema &S, Decl *D,
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 1)) {
-    Attr.setInvalid();
-    return;
-  }
   Expr *priorityExpr = Attr.getArgAsExpr(0);
   
   llvm::APSInt priority(32);
@@ -3216,9 +3041,6 @@ static void handleFormatAttr(Sema &S, Decl *D, const AttributeList &Attr) {
       << Attr.getName() << 1 << AANT_ArgumentIdentifier;
     return;
   }
-  
-  if (!checkAttributeNumArgs(S, Attr, 3))
-    return;
 
   if (!isFunctionOrMethodOrBlock(D) || !hasFunctionProto(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
@@ -3356,11 +3178,6 @@ static void handleFormatAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleTransparentUnionAttr(Sema &S, Decl *D,
                                        const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
-
   // Try to find the underlying union declaration.
   RecordDecl *RD = 0;
   TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D);
@@ -3424,10 +3241,6 @@ static void handleTransparentUnionAttr(Sema &S, Decl *D,
 }
 
 static void handleAnnotateAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   Expr *ArgExpr = Attr.getArgAsExpr(0);
   StringLiteral *SE = dyn_cast<StringLiteral>(ArgExpr);
 
@@ -3629,9 +3442,6 @@ static void handleModeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
     return;
   }
   
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   IdentifierInfo *Name = Attr.getArgAsIdent(0)->Ident;
   StringRef Str = Name->getName();
 
@@ -3794,10 +3604,6 @@ static void handleModeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleNoDebugAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
     if (!VD->hasGlobalStorage())
       S.Diag(Attr.getLoc(),
@@ -3816,11 +3622,6 @@ static void handleNoDebugAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleNoInlineAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -3834,11 +3635,6 @@ static void handleNoInlineAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleNoInstrumentFunctionAttr(Sema &S, Decl *D,
                                            const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
-
   if (!isa<FunctionDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedFunction;
@@ -3852,9 +3648,6 @@ static void handleNoInstrumentFunctionAttr(Sema &S, Decl *D,
 
 static void handleConstantAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (S.LangOpts.CUDA) {
-    if (!checkAttributeNumArgs(S, Attr, 0))
-      return;
-
     if (!isa<VarDecl>(D)) {
       S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
         << Attr.getName() << ExpectedVariable;
@@ -3894,10 +3687,6 @@ static void handleDeviceAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleGlobalAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (S.LangOpts.CUDA) {
-    // check the attribute arguments.
-    if (!checkAttributeNumArgs(S, Attr, 0))
-      return;
-
     if (!isa<FunctionDecl>(D)) {
       S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
         << Attr.getName() << ExpectedFunction;
@@ -3929,11 +3718,6 @@ static void handleGlobalAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleHostAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (S.LangOpts.CUDA) {
-    // check the attribute arguments.
-    if (!checkAttributeNumArgs(S, Attr, 0))
-      return;
-
-
     if (!isa<FunctionDecl>(D)) {
       S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
         << Attr.getName() << ExpectedFunction;
@@ -3950,10 +3734,6 @@ static void handleHostAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 
 static void handleSharedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (S.LangOpts.CUDA) {
-    // check the attribute arguments.
-    if (!checkAttributeNumArgs(S, Attr, 0))
-      return;
-
     if (!isa<VarDecl>(D)) {
       S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
         << Attr.getName() << ExpectedVariable;
@@ -3969,10 +3749,6 @@ static void handleSharedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
 }
 
 static void handleGNUInlineAttr(Sema &S, Decl *D, const AttributeList &Attr) {
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 0))
-    return;
-
   FunctionDecl *Fn = dyn_cast<FunctionDecl>(D);
   if (Fn == 0) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
@@ -4680,10 +4456,6 @@ static void handleUuidAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (!checkMicrosoftExt(S, Attr, S.LangOpts.Borland))
     return;
 
-  // check the attribute arguments.
-  if (!checkAttributeNumArgs(S, Attr, 1))
-    return;
-
   Expr *Arg = Attr.getArgAsExpr(0);
   StringLiteral *Str = dyn_cast<StringLiteral>(Arg);
   if (!Str || !Str->isAscii()) {
@@ -4771,6 +4543,29 @@ static void handleSelectAnyAttr(Sema &S, Decl *D, const AttributeList &Attr) {
                            Attr.getAttributeSpellingListIndex()));
 }
 
+/// Handles semantic checking for features that are common to all attributes,
+/// such as checking whether a parameter was properly specified, or the correct
+/// number of arguments were passed, etc.
+static bool handleCommonAttributeFeatures(Sema &S, Scope *scope, Decl *D,
+                                          const AttributeList &Attr) {
+  // Several attributes carry different semantics than the parsing requires, so
+  // those are opted out of the common handling.
+  //
+  // We also bail on unknown and ignored attributes because those are handled
+  // as part of the target-specific handling logic.
+  if (Attr.hasCustomParsing() ||
+      Attr.getKind() == AttributeList::UnknownAttribute ||
+      Attr.getKind() == AttributeList::IgnoredAttribute)
+    return false;
+
+  // If there are no optional arguments, then checking for the argument count
+  // is trivial.
+  if (Attr.getMinArgs() == Attr.getMaxArgs() &&
+      !checkAttributeNumArgs(S, Attr, Attr.getMinArgs()))
+    return true;
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 // Top Level Sema Entry Points
 //===----------------------------------------------------------------------===//
@@ -4789,6 +4584,9 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
   if (Attr.isCXX11Attribute() && !IncludeCXX11Attributes)
     return;
 
+  if (handleCommonAttributeFeatures(S, scope, D, Attr))
+    return;
+
   switch (Attr.getKind()) {
   case AttributeList::AT_IBAction:    handleIBAction(S, D, Attr); break;
   case AttributeList::AT_IBOutlet:    handleIBOutlet(S, D, Attr); break;