Restrict user's DSAs in struct/class member functions. Only allow static storage without using 'this'

struct S {
  static int x;
  void f() {
    #pragma oss task firstprivate(x, S::x)
    {}
 }
};

Closes llvm#40

Author: mikaoP

clang/lib/Sema/SemaOmpSs.cpp

@@ -853,17 +853,20 @@ getPrivateItem(Sema &S, Expr *&RefExpr, SourceLocation &ELoc,
   auto *DE = dyn_cast_or_null<DeclRefExpr>(RefExpr);
   auto *ME = dyn_cast_or_null<MemberExpr>(RefExpr);
 
+  // Only allow VarDecl from DeclRefExpr
+  // and VarDecl implicits from MemberExpr // (i.e. static members without 'this')
   if ((!DE || !isa<VarDecl>(DE->getDecl())) &&
       (S.getCurrentThisType().isNull() || !ME ||
        !isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts()) ||
-       !isa<FieldDecl>(ME->getMemberDecl()))) {
+       !cast<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts())->isImplicit() ||
+       !isa<VarDecl>(ME->getMemberDecl()))) {
 
     S.Diag(ELoc, diag::err_oss_expected_var_name_member_expr)
         << (S.getCurrentThisType().isNull() ? 0 : 1) << ERange;
     return nullptr;
   }
 
-  auto *VD = dyn_cast<VarDecl>(DE->getDecl());
+  auto *VD = cast<VarDecl>(DE ? DE->getDecl() : ME->getMemberDecl());
   QualType Type = VD->getType();
   if (!Type.isPODType(S.Context)) {
       S.Diag(ELoc, diag::err_oss_non_pod_not_supported) << ERange;

clang/test/OmpSs/Sema/task_dsa.c

@@ -1,10 +1,13 @@
 // RUN: %clang_cc1 -x c++ -verify -fompss-2 -ferror-limit 100 %s
 
 struct S {
-  int x;
+  static int x;
+  int y;
   void f() {
-    #pragma oss task shared(this) // expected-error {{expected variable name or data member of current class}}
-    {}
+    #pragma oss task shared(this, *this, y, this->y, this->x) // expected-error {{expected variable name or data member of current class}} expected-error {{expected variable name or data member of current class}} expected-error {{expected variable name or data member of current class}} expected-error {{expected variable name or data member of current class}} expected-error {{expected variable name or data member of current class}}
+    { /* ERROR */ }
+    #pragma oss task shared(x, S::x)
+    { /* FINE */ }
   }
 };