[OpenMP] DSAChecker bug fix for combined directives.

[arpith-jacob]

Summary

The DSAChecker code in SemaOpenMP looks at the captured statement
associated with an OpenMP directive. A combined directive such as
'target parallel' has nested capture statements, which have to be
fully traversed before executing the DSAChecker. This is a patch
to perform the traversal for such combined directives.

[ABataev]

LG

cfe/trunk/lib/Sema/SemaOpenMP.cpp

StmtResult Sema::ActOnOpenMPExecutableDirective(
   llvm::DenseMap<ValueDecl *, Expr *> VarsWithInheritedDSA;
   bool ErrorFound = false;
   ClausesWithImplicit.append(Clauses.begin(), Clauses.end());
   if (AStmt) {
     assert(isa<CapturedStmt>(AStmt) && "Captured statement expected");
 
     // Check default data sharing attributes for referenced variables.
     DSAAttrChecker DSAChecker(DSAStack, *this, cast<CapturedStmt>(AStmt));
-    DSAChecker.Visit(cast<CapturedStmt>(AStmt)->getCapturedStmt());
+    int ThisCaptureLevel = getOpenMPCaptureLevels(Kind);
+    Stmt *S = AStmt;
+    while (--ThisCaptureLevel >= 0)
+      S = cast<CapturedStmt>(S)->getCapturedStmt();
+    DSAChecker.Visit(S);
     if (DSAChecker.isErrorFound())
       return StmtError();
     // Generate list of implicitly defined firstprivate variables.
     VarsWithInheritedDSA = DSAChecker.getVarsWithInheritedDSA();
 
     if (!DSAChecker.getImplicitFirstprivate().empty()) {
       if (OMPClause *Implicit = ActOnOpenMPFirstprivateClause(
               DSAChecker.getImplicitFirstprivate(), SourceLocation(),

cfe/trunk/test/OpenMP/target_parallel_default_messages.cpp

int main(int argc, char **argv) {
 
   #pragma omp target parallel default(none)
   ++argc; // expected-error {{variable 'argc' must have explicitly specified data sharing attributes}}
 
   #pragma omp target parallel default(none)
   foo();
   #pragma omp target parallel default(shared)
   ++argc;
+  #pragma omp target parallel default(none)
+  #pragma omp parallel default(shared)
+  ++argc;
   return 0;
 }