[flang-commits] [flang] Skip POINTER components in implicit mapper generation (PR #177848)

[via flang-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-fir-hlfir

Author: Deval Gupta (devalgupta404)

<details>
<summary>Changes</summary>

closes #<!-- -->176956 
This PR skips POINTER components when checking if a derived type requires an implicit mapper to prevent incorrect deep copy behavior

---
Full diff: https://github.com/llvm/llvm-project/pull/177848.diff


2 Files Affected:

- (modified) flang/lib/Lower/OpenMP/Utils.cpp (+3) 
- (added) flang/test/Lower/OpenMP/pointer-components.f90 (+46) 


``````````diff
diff --git a/flang/lib/Lower/OpenMP/Utils.cpp b/flang/lib/Lower/OpenMP/Utils.cpp
index dce8580856664..93b90c1a5694a 100644
--- a/flang/lib/Lower/OpenMP/Utils.cpp
+++ b/flang/lib/Lower/OpenMP/Utils.cpp
@@ -193,6 +193,9 @@ bool requiresImplicitDefaultDeclareMapper(
       if (component.attrs().test(semantics::Attr::ALLOCATABLE))
         return true;
 
+      if (component.attrs().test(semantics::Attr::POINTER))
+        continue;
+
       if (const semantics::DeclTypeSpec *declType = component.GetType())
         if (const auto *nested = declType->AsDerived())
           if (requiresMapper(*nested))
diff --git a/flang/test/Lower/OpenMP/pointer-components.f90 b/flang/test/Lower/OpenMP/pointer-components.f90
new file mode 100644
index 0000000000000..59898dc53d5bf
--- /dev/null
+++ b/flang/test/Lower/OpenMP/pointer-components.f90
@@ -0,0 +1,46 @@
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=52 %s -o - | FileCheck %s
+
+! Test 1: POINTER-only derieved type should not trigger implicit mapper 
+subroutine test_pointer_only
+  type :: dt_pointer
+    real, pointer :: p(:)
+  end type
+
+  type(dt_pointer) :: obj
+
+  ! CHECK-NOT: omp.declare_mapper @{{.*}}dt_pointer
+  !$omp target map(tofrom: obj)
+  !$omp end target
+end subroutine test_pointer_only
+
+! Test 2: POINTER to derieved type with ALLOCATABLE must not trigger mapper 
+subroutine test_pointer_to_allocatable_dt
+  type :: inner_dt
+    real, allocatable :: data(:)
+  end type
+
+  type :: outer_dt
+    type(inner_dt), pointer :: nested_ptr
+  end type
+
+  type(outer_dt) :: obj
+
+  ! CHECK-NOT: omp.declare_mapper @{{.*}}outer_dt
+  !$omp target map(tofrom: obj)
+  !$omp end target
+end subroutine test_pointer_to_allocatable_dt
+
+! Test 3: ALLOCATABLE member must still trigger mapper
+subroutine test_allocatable_still_triggers_mapper
+  type :: alloc_dt
+    real, allocatable :: a(:)
+  end type
+
+  type(alloc_dt) :: obj
+  allocate(obj%a(4))
+
+  ! CHECK: omp.declare_mapper @{{.*}}alloc_dt
+  !$omp target map(tofrom: obj)
+    obj%a(1) = 1.0
+  !$omp end target
+end subroutine test_allocatable_still_triggers_mapper
\ No newline at end of file

``````````

</details>


https://github.com/llvm/llvm-project/pull/177848