[OpenMP] Ignore parens in atomic capture

[• davidsh]

Summary

Clang misdiagnoses atomic captures cases that contains parens.
ie.
int v, int *p;
#pragma omp atomic capture
{ v = (*p); (*p)++; }

[ABataev]

LG

lib/Sema/SemaOpenMP.cpp

if (AtomicBody->getType()->isScalarType() ||
         AtomicBody->isInstantiationDependent()) {
       if (auto *AtomicCompAssignOp = dyn_cast<CompoundAssignOperator>(
               AtomicBody->IgnoreParenImpCasts())) {
         // Check for Compound Assignment Operation
         Op = BinaryOperator::getOpForCompoundAssignment(
             AtomicCompAssignOp->getOpcode());
         OpLoc = AtomicCompAssignOp->getOperatorLoc();
         E = AtomicCompAssignOp->getRHS();
-        X = AtomicCompAssignOp->getLHS();
+        X = AtomicCompAssignOp->getLHS()->IgnoreParens();
         IsXLHSInRHSPart = true;
       } else if (auto *AtomicBinOp = dyn_cast<BinaryOperator>(
                      AtomicBody->IgnoreParenImpCasts())) {
         // Check for Binary Operation
         if(checkBinaryOperation(AtomicBinOp, DiagId, NoteId))
           return true;
       } else if (auto *AtomicUnaryOp =
                  dyn_cast<UnaryOperator>(AtomicBody->IgnoreParenImpCasts())) {
         // Check for Unary Operation
         if (AtomicUnaryOp->isIncrementDecrementOp()) {
           IsPostfixUpdate = AtomicUnaryOp->isPostfix();
           Op = AtomicUnaryOp->isIncrementOp() ? BO_Add : BO_Sub;
           OpLoc = AtomicUnaryOp->getOperatorLoc();
-          X = AtomicUnaryOp->getSubExpr();
+          X = AtomicUnaryOp->getSubExpr()->IgnoreParens();
           E = SemaRef.ActOnIntegerConstant(OpLoc, /*uint64_t Val=*/1).get();
           IsXLHSInRHSPart = true;
         } else {
           ErrorFound = NotAnUnaryIncDecExpression;
           ErrorLoc = AtomicUnaryOp->getExprLoc();
           ErrorRange = AtomicUnaryOp->getSourceRange();
           NoteLoc = AtomicUnaryOp->getOperatorLoc();
           NoteRange = SourceRange(NoteLoc, NoteLoc);

test/OpenMP/atomic_messages.c

#pragma omp atomic capture
   c = a = b >> a;
 #pragma omp atomic capture
   { c = *&a; *&a = *&a +  2;}
 #pragma omp atomic capture
   { *&a = *&a +  2; c = *&a;}
 #pragma omp atomic capture
   {c = a; a++;}
 #pragma omp atomic capture
+  {c = a; (a)++;}
+#pragma omp atomic capture
   {++a;c = a;}
 #pragma omp atomic capture
   {c = a;a--;}
 #pragma omp atomic capture
   {--a;c = a;}
 #pragma omp atomic capture
   {c = a; a += b;}
 #pragma omp atomic capture
+  {c = a; (a) += b;}
+#pragma omp atomic capture
   {a %= b; c = a;}
 #pragma omp atomic capture
   {c = a; a *= b;}
 #pragma omp atomic capture
   {a -= b;c = a;}
 #pragma omp atomic capture
   {c = a; a /= b;}
 #pragma omp atomic capture

test/OpenMP/atomic_messages.cpp

#pragma omp atomic capture
   c = a = b >> a;
 #pragma omp atomic capture
   { c = *&a; *&a = *&a +  2;}
 #pragma omp atomic capture
   { *&a = *&a +  2; c = *&a;}
 #pragma omp atomic capture
   {c = a; a++;}
 #pragma omp atomic capture
+  {c = a; (a)++;}
+#pragma omp atomic capture
   {++a;c = a;}
 #pragma omp atomic capture
   {c = a;a--;}
 #pragma omp atomic capture
   {--a;c = a;}
 #pragma omp atomic capture
   {c = a; a += b;}
 #pragma omp atomic capture
+  {c = a; (a) += b;}
+#pragma omp atomic capture
   {a %= b; c = a;}
 #pragma omp atomic capture
   {c = a; a *= b;}
 #pragma omp atomic capture
   {a -= b;c = a;}
 #pragma omp atomic capture
   {c = a; a /= b;}
 #pragma omp atomic capture