Sema: produce error when invalid ordering is passed to atomic builtin
This is a conservative check, because it's valid for the expression to be
non-constant, and in cases like that we just don't know whether it's valid.
rdar://problem/16242991
llvm-svn: 203561
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 512916e..19e61b2 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -911,6 +911,33 @@
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 @@
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());