[clang][OpenMP] 6.0: 'allocatable' variable-category is not valid for C/C++ (#167735)

The variable-category 'allocatable' is explicitly noted as applying only
to Fortran. If specified in C/C++ it should generate an error. NOTE:
Issue will be filed against OpenMP 6.0 specification that restriction is
missing from 'default' clause section.

From the OpenMP 6.0 specification:
  Section 7.5.1 default Clause
    Semantics, under Fortran only, L18-19, pg. 223
The allocatable variable-category specifies variables with the
ALLOCATABLE
    attribute.

  Section 7.9.9 defaultmap Clause
    Semantics, under Fortran only, L9-10, pg. 292
The allocatable variable-category specifies variables with the
ALLOCATABLE
    attribute.

    Restrictions, C/C++
      L1, pg. 293
      The specified variable-category must not be allocatable.

Author: ddpagan

clang/include/clang/Basic/OpenMPKinds.def

@@ -127,7 +127,6 @@ OPENMP_DEVICE_MODIFIER(device_num)
 // Variable-category attributes for 'default' clause.
 OPENMP_DEFAULT_VARIABLE_CATEGORY(aggregate)
 OPENMP_DEFAULT_VARIABLE_CATEGORY(all)
-OPENMP_DEFAULT_VARIABLE_CATEGORY(allocatable)
 OPENMP_DEFAULT_VARIABLE_CATEGORY(pointer)
 OPENMP_DEFAULT_VARIABLE_CATEGORY(scalar)
 

clang/lib/Sema/SemaOpenMP.cpp

@@ -78,11 +78,10 @@ enum DefaultDataSharingAttributes {
 /// Not mentioning any Variable category attribute indicates
 /// the modifier (DefaultDataSharingAttributes) is for all variables.
 enum DefaultDataSharingVCAttributes {
-  DSA_VC_all = 0,     /// for all variables.
-  DSA_VC_aggregate,   /// for aggregate variables.
-  DSA_VC_allocatable, /// for allocatable variables.
-  DSA_VC_pointer,     /// for pointer variables.
-  DSA_VC_scalar,      /// for scalar variables.
+  DSA_VC_all = 0,   /// for all variables.
+  DSA_VC_aggregate, /// for aggregate variables.
+  DSA_VC_pointer,   /// for pointer variables.
+  DSA_VC_scalar,    /// for scalar variables.
 };
 
 /// Stack for tracking declarations used in OpenMP directives and
@@ -760,11 +759,6 @@ class DSAStackTy {
     getTopOfStack().DefaultVCAttr = DSA_VC_all;
     getTopOfStack().DefaultAttrVCLoc = VCLoc;
   }
-  /// Set default data sharing variable category attribute to allocatable.
-  void setDefaultDSAVCAllocatable(SourceLocation VCLoc) {
-    getTopOfStack().DefaultVCAttr = DSA_VC_allocatable;
-    getTopOfStack().DefaultAttrVCLoc = VCLoc;
-  }
   /// Set default data sharing variable category attribute to pointer.
   void setDefaultDSAVCPointer(SourceLocation VCLoc) {
     getTopOfStack().DefaultVCAttr = DSA_VC_pointer;
@@ -1373,11 +1367,6 @@ DSAStackTy::DSAVarData DSAStackTy::getDSA(const_iterator &Iter,
     if (!VD->getType()->isAggregateType())
       IterDA = DSA_none;
     break;
-  case DSA_VC_allocatable:
-    if (!(VD->getType()->isPointerType() ||
-          VD->getType()->isVariableArrayType()))
-      IterDA = DSA_none;
-    break;
   case DSA_VC_pointer:
     if (!VD->getType()->isPointerType())
       IterDA = DSA_none;

clang/test/OpenMP/parallel_default_messages.cpp

@@ -64,6 +64,11 @@ int main(int argc, char **argv) {
     ++x;
     ++y;
   }
+#pragma omp parallel default(private: allocatable) private(x,y) // expected-error {{wrong variable category specified with modifier private in the default clause}}
+  {
+    ++x;
+    ++y;
+  }
 #endif
   return 0;
 }