[OPENMP] Fix PR47999: correctly map implicit firstprivates in outer tasks.

[ABataev]

Summary

If the variable is implicitly firstprivatized in the inner task-based
region, it also must be firstprivatized in outer task-based regions.
Previously firstprivates were captured in tasks but later it was
optimized to reduce the memory usage. But still need to mark such
variables as implicit firstprivate in outer tasks.

[jdoerfert]

LGTM

clang/lib/Sema/SemaOpenMP.cpp

public:
   }
   void VisitOMPExecutableDirective(OMPExecutableDirective *S) {
     for (OMPClause *C : S->clauses()) {
       // Skip analysis of arguments of implicitly defined firstprivate clause
       // for task|target directives.
       // Skip analysis of arguments of implicitly defined map clause for target
       // directives.
       if (C && !((isa<OMPFirstprivateClause>(C) || isa<OMPMapClause>(C)) &&
-                 C->isImplicit())) {
+                 C->isImplicit() &&
+                 !isOpenMPTaskingDirective(Stack->getCurrentDirective()))) {
         for (Stmt *CC : C->children()) {
           if (CC)
             Visit(CC);
         }
       }
     }
     // Check implicitly captured variables.
     VisitSubCaptures(S);

clang/test/OpenMP/task_in_task_firstprivate_codegen.cpp

+// RUN: %clang_cc1 -verify -triple x86_64-apple-darwin10 -fopenmp -x c++ -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -x c++ -triple x86_64-apple-darwin10 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -x c++ -triple x86_64-apple-darwin10 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
+
+// RUN: %clang_cc1 -verify -triple x86_64-apple-darwin10 -fopenmp-simd -x c++ -emit-llvm %s -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -fopenmp-simd -x c++ -triple x86_64-apple-darwin10 -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -x c++ -triple x86_64-apple-darwin10 -include-pch %t -verify %s -emit-llvm -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// SIMD-ONLY0-NOT: {{__kmpc|__tgt}}
+// expected-no-diagnostics
+#ifndef HEADER
+#define HEADER
+
+// CHECK: @main
+int main() {
+  double var = 0;
+  // Check that var is firstprivatized in the outermost task.
+  // CHECK: [[BASE:%.+]] = call i8* @__kmpc_omp_task_alloc(%struct.ident_t* @{{.+}}, i32 {{.+}}, i32 1, i64 48, i64 1, i32 (i32, i8*)* bitcast (i32 (i32, [[TASK_TY:%.+]]*)* @{{.+}} to i32 (i32, i8*)*))
+  // CHECK: [[TD:%.+]] = bitcast i8* [[BASE]] to [[TASK_TY]]*
+  // CHECK: [[PRIVS:%.+]] = getelementptr inbounds [[TASK_TY]], [[TASK_TY]]* [[TD]], i32 0, i32 1
+  // CHECK: [[VAR_FP:%.+]] = getelementptr inbounds %{{.+}}, %{{.+}}* [[PRIVS]], i32 0, i32 0
+  // CHECK: [[VAR_VAL:%.+]] = load double, double* %{{.+}},
+  // CHECK: store double [[VAR_VAL]], double* [[VAR_FP]],
+  // CHECK: call i32 @__kmpc_omp_task(%struct.ident_t* @{{.+}}, i32 %{{.+}}, i8* [[BASE]])
+#pragma omp task
+#pragma omp task
+  var += 1;
+  return 0;
+}
+
+#endif