2 files changed, 47 insertions, 21 deletions

diff --git a/clang/lib/CodeGen/CGAtomic.cpp b/clang/lib/CodeGen/CGAtomic.cpp
index b5a494e2879..dcb3ff10335 100644
--- a/clang/lib/CodeGen/CGAtomic.cpp
+++ b/clang/lib/CodeGen/CGAtomic.cpp
@@ -24,16 +24,6 @@
 using namespace clang;
 using namespace CodeGen;
 
-// The ABI values for various atomic memory orderings.
-enum AtomicOrderingKind {
-  AO_ABI_memory_order_relaxed = 0,
-  AO_ABI_memory_order_consume = 1,
-  AO_ABI_memory_order_acquire = 2,
-  AO_ABI_memory_order_release = 3,
-  AO_ABI_memory_order_acq_rel = 4,
-  AO_ABI_memory_order_seq_cst = 5
-};
-
 namespace {
   class AtomicInfo {
     CodeGenFunction &CGF;
@@ -642,30 +632,30 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) {
   if (isa<llvm::ConstantInt>(Order)) {
     int ord = cast<llvm::ConstantInt>(Order)->getZExtValue();
     switch (ord) {
-    case AO_ABI_memory_order_relaxed:
+    case AtomicExpr::AO_ABI_memory_order_relaxed:
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::Monotonic);
       break;
-    case AO_ABI_memory_order_consume:
-    case AO_ABI_memory_order_acquire:
+    case AtomicExpr::AO_ABI_memory_order_consume:
+    case AtomicExpr::AO_ABI_memory_order_acquire:
       if (IsStore)
         break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::Acquire);
       break;
-    case AO_ABI_memory_order_release:
+    case AtomicExpr::AO_ABI_memory_order_release:
       if (IsLoad)
         break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::Release);
       break;
-    case AO_ABI_memory_order_acq_rel:
+    case AtomicExpr::AO_ABI_memory_order_acq_rel:
       if (IsLoad || IsStore)
         break; // Avoid crashing on code with undefined behavior
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::AcquireRelease);
       break;
-    case AO_ABI_memory_order_seq_cst:
+    case AtomicExpr::AO_ABI_memory_order_seq_cst:
       EmitAtomicOp(*this, E, Dest, Ptr, Val1, Val2, Size, Align,
                    llvm::SequentiallyConsistent);
       break;
@@ -788,8 +778,8 @@ RValue CodeGenFunction::EmitAtomicLoad(LValue src, SourceLocation loc,
              getContext().VoidPtrTy);
     args.add(RValue::get(EmitCastToVoidPtr(tempAddr)),
              getContext().VoidPtrTy);
-    args.add(RValue::get(llvm::ConstantInt::get(IntTy,
-                                                AO_ABI_memory_order_seq_cst)),
+    args.add(RValue::get(llvm::ConstantInt::get(
+                 IntTy, AtomicExpr::AO_ABI_memory_order_seq_cst)),
              getContext().IntTy);
     emitAtomicLibcall(*this, "__atomic_load", getContext().VoidTy, args);
 
@@ -938,8 +928,8 @@ void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, bool isInit) {
              getContext().VoidPtrTy);
     args.add(RValue::get(EmitCastToVoidPtr(srcAddr)),
              getContext().VoidPtrTy);
-    args.add(RValue::get(llvm::ConstantInt::get(IntTy,
-                                                AO_ABI_memory_order_seq_cst)),
+    args.add(RValue::get(llvm::ConstantInt::get(
+                 IntTy, AtomicExpr::AO_ABI_memory_order_seq_cst)),
              getContext().IntTy);
     emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args);
     return;
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 512916e9a8e..19e61b2e819 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -911,6 +911,33 @@ bool Sema::CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto) {
   return false;
 }
 
+static bool isValidOrderingForOp(int64_t Ordering, AtomicExpr::AtomicOp Op) {
+  if (Ordering < AtomicExpr::AO_ABI_memory_order_relaxed ||
+      Ordering > AtomicExpr::AO_ABI_memory_order_seq_cst)
+    return false;
+
+  switch (Op) {
+  case AtomicExpr::AO__c11_atomic_init:
+    llvm_unreachable("There is no ordering argument for an init");
+
+  case AtomicExpr::AO__c11_atomic_load:
+  case AtomicExpr::AO__atomic_load_n:
+  case AtomicExpr::AO__atomic_load:
+    return Ordering != AtomicExpr::AO_ABI_memory_order_release &&
+           Ordering != AtomicExpr::AO_ABI_memory_order_acq_rel;
+
+  case AtomicExpr::AO__c11_atomic_store:
+  case AtomicExpr::AO__atomic_store:
+  case AtomicExpr::AO__atomic_store_n:
+    return Ordering != AtomicExpr::AO_ABI_memory_order_consume &&
+           Ordering != AtomicExpr::AO_ABI_memory_order_acquire &&
+           Ordering != AtomicExpr::AO_ABI_memory_order_acq_rel;
+
+  default:
+    return true;
+  }
+}
+
 ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
                                          AtomicExpr::AtomicOp Op) {
   CallExpr *TheCall = cast<CallExpr>(TheCallResult.get());
@@ -1199,7 +1226,16 @@ ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
     SubExprs.push_back(TheCall->getArg(3)); // Weak
     break;
   }
-  
+
+  if (SubExprs.size() >= 2 && Form != Init) {
+    llvm::APSInt Result(32);
+    if (SubExprs[1]->isIntegerConstantExpr(Result, Context) &&
+        !isValidOrderingForOp(Result.getSExtValue(), Op))
+      return ExprError(Diag(SubExprs[1]->getLocStart(),
+                            diag::err_atomic_op_has_invalid_memory_order)
+                       << SubExprs[1]->getSourceRange());
+  }
+
   AtomicExpr *AE = new (Context) AtomicExpr(TheCall->getCallee()->getLocStart(),
                                             SubExprs, ResultType, Op,
                                             TheCall->getRParenLoc());