[Clang][OpenMP] Only check value if the expression is not instantiation dependent

Currently the following case fails:
```
template<typename Ty>
Ty foo(Ty *addr, Ty val) {
  Ty v;
#pragma omp atomic compare capture
  {
    v = *addr;
    if (*addr > val)
      *addr = val;
  }
  return v;
}
```

The compiler complains `addr` is not a lvalue. That's because when an expression
is instantiation dependent, we cannot tell if it is lvalue or not.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D135224

1 files changed, 16 insertions, 15 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index c532532..66da2e17 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -11577,6 +11577,9 @@ protected:
 
   static bool CheckValue(const Expr *E, ErrorInfoTy &ErrorInfo,
                          bool ShouldBeLValue, bool ShouldBeInteger = false) {
+    if (E->isInstantiationDependent())
+      return true;
+
     if (ShouldBeLValue && !E->isLValue()) {
       ErrorInfo.Error = ErrorTy::XNotLValue;
       ErrorInfo.ErrorLoc = ErrorInfo.NoteLoc = E->getExprLoc();
@@ -11584,25 +11587,23 @@ protected:
       return false;
     }
 
-    if (!E->isInstantiationDependent()) {
-      QualType QTy = E->getType();
-      if (!QTy->isScalarType()) {
-        ErrorInfo.Error = ErrorTy::NotScalar;
-        ErrorInfo.ErrorLoc = ErrorInfo.NoteLoc = E->getExprLoc();
-        ErrorInfo.ErrorRange = ErrorInfo.NoteRange = E->getSourceRange();
-        return false;
-      }
-      if (ShouldBeInteger && !QTy->isIntegerType()) {
-        ErrorInfo.Error = ErrorTy::NotInteger;
-        ErrorInfo.ErrorLoc = ErrorInfo.NoteLoc = E->getExprLoc();
-        ErrorInfo.ErrorRange = ErrorInfo.NoteRange = E->getSourceRange();
-        return false;
-      }
+    QualType QTy = E->getType();
+    if (!QTy->isScalarType()) {
+      ErrorInfo.Error = ErrorTy::NotScalar;
+      ErrorInfo.ErrorLoc = ErrorInfo.NoteLoc = E->getExprLoc();
+      ErrorInfo.ErrorRange = ErrorInfo.NoteRange = E->getSourceRange();
+      return false;
+    }
+    if (ShouldBeInteger && !QTy->isIntegerType()) {
+      ErrorInfo.Error = ErrorTy::NotInteger;
+      ErrorInfo.ErrorLoc = ErrorInfo.NoteLoc = E->getExprLoc();
+      ErrorInfo.ErrorRange = ErrorInfo.NoteRange = E->getSourceRange();
+      return false;
     }
 
     return true;
   }
-};
+  };
 
 bool OpenMPAtomicCompareChecker::checkCondUpdateStmt(IfStmt *S,
                                                      ErrorInfoTy &ErrorInfo) {