Fix signal during the call to checkOpenMPLoop.

[jyu2]

Summary

Fix signal during the call to checkOpenMPLoop.

The root problem is a null pointer is accessed during the call to
checkOpenMPLoop, because loop up bound expr is an error expression
due to error diagnostic was emit early.

To fix this, in setLCDeclAndLB, setUB and setStep instead return false,
return true when LB, UB or Step contains Error, so that the checking is
stopped in checkOpenMPLoop.

[ABataev]

LG

clang/lib/Sema/SemaOpenMP.cpp

 }
 
 bool OpenMPIterationSpaceChecker::setLCDeclAndLB(ValueDecl *NewLCDecl,
                                                  Expr *NewLCRefExpr,
                                                  Expr *NewLB, bool EmitDiags) {
   // State consistency checking to ensure correct usage.
   assert(LCDecl == nullptr && LB == nullptr && LCRef == nullptr &&
          UB == nullptr && Step == nullptr && !TestIsLessOp && !TestIsStrictOp);
-  if (!NewLCDecl || !NewLB)
+  if (!NewLCDecl || !NewLB || NewLB->containsErrors())
     return true;
   LCDecl = getCanonicalDecl(NewLCDecl);
   LCRef = NewLCRefExpr;
   if (auto *CE = dyn_cast_or_null<CXXConstructExpr>(NewLB))
     if (const CXXConstructorDecl *Ctor = CE->getConstructor())
       if ((Ctor->isCopyOrMoveConstructor() ||
            Ctor->isConvertingConstructor(/*AllowExplicit=*/false)) &&
           CE->getNumArgs() > 0 && CE->getArg(0) != nullptr)
         NewLB = CE->getArg(0)->IgnoreParenImpCasts();
   LB = NewLB;
   if (EmitDiags)
     InitDependOnLC = doesDependOnLoopCounter(LB, /*IsInitializer=*/true);
   return false;
 }
 
 bool OpenMPIterationSpaceChecker::setUB(Expr *NewUB,
                                         llvm::Optional<bool> LessOp,
                                         bool StrictOp, SourceRange SR,
                                         SourceLocation SL) {
   // State consistency checking to ensure correct usage.
   assert(LCDecl != nullptr && LB != nullptr && UB == nullptr &&
          Step == nullptr && !TestIsLessOp && !TestIsStrictOp);
-  if (!NewUB)
+  if (!NewUB || NewUB->containsErrors())
     return true;
   UB = NewUB;
   if (LessOp)
     TestIsLessOp = LessOp;
   TestIsStrictOp = StrictOp;
   ConditionSrcRange = SR;
   ConditionLoc = SL;
   CondDependOnLC = doesDependOnLoopCounter(UB, /*IsInitializer=*/false);
   return false;
 }
 
 bool OpenMPIterationSpaceChecker::setStep(Expr *NewStep, bool Subtract) {
   // State consistency checking to ensure correct usage.
   assert(LCDecl != nullptr && LB != nullptr && Step == nullptr);
-  if (!NewStep)
+  if (!NewStep || NewStep->containsErrors())
     return true;
   if (!NewStep->isValueDependent()) {
     // Check that the step is integer expression.
     SourceLocation StepLoc = NewStep->getBeginLoc();
     ExprResult Val = SemaRef.PerformOpenMPImplicitIntegerConversion(
         StepLoc, getExprAsWritten(NewStep));
     if (Val.isInvalid())
       return true;

clang/test/OpenMP/teams_distribute_loop_messages.cpp

 
 void test_nowait() {
 #pragma omp target
 // expected-error@+1 2 {{unexpected OpenMP clause 'nowait' in directive '#pragma omp teams distribute'}}
 #pragma omp teams distribute nowait nowait // expected-error {{directive '#pragma omp teams distribute' cannot contain more than one 'nowait' clause}}
   for (int i = 0; i < 16; ++i)
     ;
 }
+//expected-note@+1 {{candidate function not viable: requires single argument 'device_Id', but no arguments were provided}}
+int foo(int device_Id) {
+  return 2;
+}
+
+int main() {
+// expected-error@+1 {{no matching function for call to 'foo'}}
+  const int globalWI{ foo() };
+#pragma omp target teams distribute
+  for (int i=0 ; i<globalWI; i++) {}
+}