Per comment:

  Restructured/merged code that selects 'defaultmap' behavior or normal
  data-sharing-attributes depending on if associated directive is
  'target'.

Author: ddpagan

clang/lib/Sema/SemaOpenMP.cpp

@@ -17305,112 +17305,112 @@ OMPClause *SemaOpenMP::ActOnOpenMPSimpleClause(
   return Res;
 }
 
-static std::pair<OpenMPDefaultmapClauseModifier, OpenMPDefaultmapClauseKind>
-getDefaultmapModifierAndKind(llvm::omp::DefaultKind M,
-                             OpenMPDefaultClauseVariableCategory VCKind) {
+OMPClause *SemaOpenMP::ActOnOpenMPDefaultClause(
+    llvm::omp::DefaultKind M, SourceLocation MLoc,
+    OpenMPDefaultClauseVariableCategory VCKind, SourceLocation VCKindLoc,
+    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc) {
+  if (M == OMP_DEFAULT_unknown) {
+    Diag(MLoc, diag::err_omp_unexpected_clause_value)
+        << getListOfPossibleValues(OMPC_default, /*First=*/0,
+                                   /*Last=*/unsigned(OMP_DEFAULT_unknown))
+        << getOpenMPClauseNameForDiag(OMPC_default);
+    return nullptr;
+  }
+  if (VCKind == OMPC_DEFAULT_VC_unknown) {
+    Diag(VCKindLoc, diag::err_omp_default_vc)
+        << getOpenMPSimpleClauseTypeName(OMPC_default, unsigned(M));
+    return nullptr;
+  }
+  bool IsTargetDefault = getLangOpts().OpenMP >= 60 &&
+                         DSAStack->getCurrentDirective() == OMPD_target;
+
+  // OpenMP 6.0, page 224, lines 3-4 default Clause, Semantics
+  // If data-sharing-attribute is shared then the clause has no effect
+  // on a target construct;
+  if (IsTargetDefault && M == OMP_DEFAULT_shared)
+    return nullptr;
+
   OpenMPDefaultmapClauseModifier DefMapMod;
   OpenMPDefaultmapClauseKind DefMapKind;
+  std::function<void(SourceLocation)> SetDefaultDSA;
+  std::function<void(SourceLocation)> SetDefaultDSAVC;
+  // default data-sharing-attribute
   switch (M) {
   case OMP_DEFAULT_none:
     DefMapMod = OMPC_DEFAULTMAP_MODIFIER_none;
+    SetDefaultDSA = [&](SourceLocation MLoc) {
+      DSAStack->setDefaultDSANone(MLoc);
+    };
     break;
   case OMP_DEFAULT_firstprivate:
     DefMapMod = OMPC_DEFAULTMAP_MODIFIER_firstprivate;
+    SetDefaultDSA = [&](SourceLocation MLoc) {
+      DSAStack->setDefaultDSAFirstPrivate(MLoc);
+    };
     break;
   case OMP_DEFAULT_private:
     DefMapMod = OMPC_DEFAULTMAP_MODIFIER_private;
+    SetDefaultDSA = [&](SourceLocation MLoc) {
+      DSAStack->setDefaultDSAPrivate(MLoc);
+    };
+    break;
+  case OMP_DEFAULT_shared:
+    assert(!IsTargetDefault && "DSA shared invalid with target directive");
+    SetDefaultDSA = [&](SourceLocation MLoc) {
+      DSAStack->setDefaultDSAShared(MLoc);
+    };
     break;
   default:
     llvm_unreachable("unexpected DSA in OpenMP default clause");
   }
+  // default variable-category
   switch (VCKind) {
   case OMPC_DEFAULT_VC_aggregate:
     DefMapKind = OMPC_DEFAULTMAP_aggregate;
+    SetDefaultDSAVC = [&](SourceLocation VCKindLoc) {
+      DSAStack->setDefaultDSAVCAggregate(VCKindLoc);
+    };
     break;
   case OMPC_DEFAULT_VC_pointer:
     DefMapKind = OMPC_DEFAULTMAP_pointer;
+    SetDefaultDSAVC = [&](SourceLocation VCKindLoc) {
+      DSAStack->setDefaultDSAVCPointer(VCKindLoc);
+    };
     break;
   case OMPC_DEFAULT_VC_scalar:
     DefMapKind = OMPC_DEFAULTMAP_scalar;
+    SetDefaultDSAVC = [&](SourceLocation VCKindLoc) {
+      DSAStack->setDefaultDSAVCScalar(VCKindLoc);
+    };
     break;
   case OMPC_DEFAULT_VC_all:
     DefMapKind = OMPC_DEFAULTMAP_all;
+    SetDefaultDSAVC = [&](SourceLocation VCKindLoc) {
+      DSAStack->setDefaultDSAVCAll(VCKindLoc);
+    };
     break;
   default:
     llvm_unreachable("unexpected variable category in OpenMP default clause");
   }
-  return std::make_pair(DefMapMod, DefMapKind);
-}
 
-OMPClause *SemaOpenMP::ActOnOpenMPDefaultClause(
-    llvm::omp::DefaultKind M, SourceLocation MLoc,
-    OpenMPDefaultClauseVariableCategory VCKind, SourceLocation VCKindLoc,
-    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc) {
-  if (M == OMP_DEFAULT_unknown) {
-    Diag(MLoc, diag::err_omp_unexpected_clause_value)
-        << getListOfPossibleValues(OMPC_default, /*First=*/0,
-                                   /*Last=*/unsigned(OMP_DEFAULT_unknown))
-        << getOpenMPClauseNameForDiag(OMPC_default);
-    return nullptr;
-  }
-
-  if (getLangOpts().OpenMP >= 60 &&
-      DSAStack->getCurrentDirective() == OMPD_target) {
-    // OpenMP 6.0 (see page 224, lines 3-5) default Clause, Semantics
-    // If data-sharing-attribute is shared then the clause has no effect
-    // on a target construct; otherwise, its effect on a target construct is
-    // equivalent to specifying the defaultmap clause with the same
-    // data-sharing-attribute and variable-category.
-    if (M != OMP_DEFAULT_shared) {
-      auto [DefMapMod, DefMapKind] = getDefaultmapModifierAndKind(M, VCKind);
-      if (DefMapKind == OMPC_DEFAULTMAP_all) {
-        DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_aggregate, MLoc);
-        DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_scalar, MLoc);
-        DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_pointer, MLoc);
-      } else {
-        DSAStack->setDefaultDMAAttr(DefMapMod, DefMapKind, MLoc);
-      }
+  // OpenMP 6.0, page 224, lines 4-5 default Clause, Semantics
+  // otherwise, its effect on a target construct is equivalent to
+  // specifying the defaultmap clause with the same data-sharing-attribute
+  // and variable-category.
+  if (IsTargetDefault) {
+    if (DefMapKind == OMPC_DEFAULTMAP_all) {
+      DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_aggregate, MLoc);
+      DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_scalar, MLoc);
+      DSAStack->setDefaultDMAAttr(DefMapMod, OMPC_DEFAULTMAP_pointer, MLoc);
+    } else {
+      DSAStack->setDefaultDMAAttr(DefMapMod, DefMapKind, MLoc);
     }
   } else {
-    switch (M) {
-    case OMP_DEFAULT_none:
-      DSAStack->setDefaultDSANone(MLoc);
-      break;
-    case OMP_DEFAULT_shared:
-      DSAStack->setDefaultDSAShared(MLoc);
-      break;
-    case OMP_DEFAULT_firstprivate:
-      DSAStack->setDefaultDSAFirstPrivate(MLoc);
-      break;
-    case OMP_DEFAULT_private:
-      DSAStack->setDefaultDSAPrivate(MLoc);
-      break;
-    default:
-      llvm_unreachable("DSA unexpected in OpenMP default clause");
-    }
-  }
-
-  switch (VCKind) {
-  case OMPC_DEFAULT_VC_aggregate:
-    DSAStack->setDefaultDSAVCAggregate(VCKindLoc);
-    break;
-  case OMPC_DEFAULT_VC_all:
-    DSAStack->setDefaultDSAVCAll(VCKindLoc);
-    break;
-  case OMPC_DEFAULT_VC_allocatable:
-    DSAStack->setDefaultDSAVCAllocatable(VCKindLoc);
-    break;
-  case OMPC_DEFAULT_VC_pointer:
-    DSAStack->setDefaultDSAVCPointer(VCKindLoc);
-    break;
-  case OMPC_DEFAULT_VC_scalar:
-    DSAStack->setDefaultDSAVCScalar(VCKindLoc);
-    break;
-  default:
-    Diag(VCKindLoc, diag::err_omp_default_vc)
-        << getOpenMPSimpleClauseTypeName(OMPC_default, unsigned(M));
+    // If earlier than OpenMP 6.0, or not a target directive, then set
+    // default DSA as before.
+    SetDefaultDSA(MLoc);
+    SetDefaultDSAVC(VCKindLoc);
   }
-
   return new (getASTContext())
       OMPDefaultClause(M, MLoc, VCKind, VCKindLoc, StartLoc, LParenLoc, EndLoc);
 }