[OPENMP]Add check for undefined behavior with thread allocators on

target and task-based directives.

According to OpenMP 5.0, 2.11.4 allocate Clause, Restrictions, For task,
taskloop or target directives, allocation requests to memory allocators
with the trait access set to thread result in unspecified behavior.
Patch introduces a check for omp_thread_mem_alloc predefined allocator
on target- and trask-based directives.

llvm-svn: 357205

1 files changed, 33 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index b4c8a644a39..0971277de75 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3640,6 +3640,33 @@ static bool checkIfClauses(Sema &S, OpenMPDirectiveKind Kind,
   return ErrorFound;
 }
 
+static bool checkAllocateClauses(Sema &S, DSAStackTy *Stack,
+                                 ArrayRef<OMPClause *> Clauses) {
+  assert(!S.CurContext->isDependentContext() &&
+         "Expected non-dependent context.");
+  bool IsCorrect = true;
+  auto AllocateRange =
+      llvm::make_filter_range(Clauses, OMPAllocateClause::classof);
+  for (OMPClause *C : AllocateRange) {
+    auto *AC = cast<OMPAllocateClause>(C);
+    OMPAllocateDeclAttr::AllocatorTypeTy AllocatorKind =
+        getAllocatorKind(S, Stack, AC->getAllocator());
+    // OpenMP, 2.11.4 allocate Clause, Restrictions.
+    // For task, taskloop or target directives, allocation requests to memory
+    // allocators with the trait access set to thread result in unspecified
+    // behavior.
+    if (AllocatorKind == OMPAllocateDeclAttr::OMPThreadMemAlloc &&
+        (isOpenMPTaskingDirective(Stack->getCurrentDirective()) ||
+         isOpenMPTargetExecutionDirective(Stack->getCurrentDirective()))) {
+      S.Diag(AC->getAllocator()->getExprLoc(),
+             diag::warn_omp_allocate_thread_on_task_target_directive)
+          << getOpenMPDirectiveName(Stack->getCurrentDirective());
+      continue;
+    }
+  }
+  return !IsCorrect;
+}
+
 StmtResult Sema::ActOnOpenMPExecutableDirective(
     OpenMPDirectiveKind Kind, const DeclarationNameInfo &DirName,
     OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
@@ -3973,6 +4000,12 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     ErrorFound = checkIfClauses(*this, Kind, Clauses, AllowedNameModifiers) ||
                  ErrorFound;
 
+  // Check allocate clauses.
+  if (!CurContext->isDependentContext()) {
+    ErrorFound = checkAllocateClauses(*this, DSAStack, ClausesWithImplicit) ||
+                 ErrorFound;
+  }
+
   if (ErrorFound)
     return StmtError();