[Flang][OpenMP] Fix defaultmap(none) being overly aggressive with symbol checks

[agozillon]

Currently we're picking up and complaining about builtin (and procedure) symbols like null() when defaultmap(none) is set, so I've relaxed the restriction a bit to allow for procedures and named constants to bypass the restriction. It might be the case that we want to tighten it up again in certain aspects in the future.

[llvmbot]

@llvm/pr-subscribers-flang-openmp

@llvm/pr-subscribers-flang-semantics

Author: None (agozillon)

Changes

Currently we're picking up and complaining about builtin (and procedure) symbols like null() when defaultmap(none) is set, so I've relaxed the restriction a bit to allow for procedures and named constants to bypass the restriction. It might be the case that we want to tighten it up again in certain aspects in the future.

---

Full diff: https://github.com/llvm/llvm-project/pull/167806.diff

2 Files Affected:

• (modified) flang/lib/Semantics/resolve-directives.cpp (+7-2)
• (modified) flang/test/Semantics/OpenMP/defaultmap-clause-none.f90 (+37)

diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index 224c69163b85e..71665355aed1a 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -3070,8 +3070,13 @@ void OmpAttributeVisitor::Post(const parser::Name &name) {
       // place for the types specified.
       if (Symbol * found{currScope().FindSymbol(name.source)}) {
         // If the variable has declare target applied to it (enter or link) it
-        // is exempt from defaultmap(none) restrictions
-        if (!symbol->GetUltimate().test(Symbol::Flag::OmpDeclareTarget)) {
+        // is exempt from defaultmap(none) restrictions.
+        // We also exempt procedures and named constants from defaultmap(none)
+        // checking.
+        if (!symbol->GetUltimate().test(Symbol::Flag::OmpDeclareTarget) &&
+            !(IsProcedure(*symbol) &&
+                !semantics::IsProcedurePointer(*symbol)) &&
+            !IsNamedConstant(*symbol)) {
           auto &dMap = GetContext().defaultMap;
           for (auto defaults : dMap) {
             if (defaults.second ==
diff --git a/flang/test/Semantics/OpenMP/defaultmap-clause-none.f90 b/flang/test/Semantics/OpenMP/defaultmap-clause-none.f90
index 08e8ebc995097..0b74e3412e472 100644
--- a/flang/test/Semantics/OpenMP/defaultmap-clause-none.f90
+++ b/flang/test/Semantics/OpenMP/defaultmap-clause-none.f90
@@ -94,3 +94,40 @@ subroutine defaultmap_aggregate_none
         end do
     !$omp end target
 end subroutine defaultmap_aggregate_none
+
+! Verify we do not catch null in defaultmap(none)
+subroutine defaultmap_builtin_none
+    implicit none
+    integer,  pointer :: ptr(:)
+
+    !$omp target defaultmap(none) map(ptr)
+!CHECK-NOT: The DEFAULTMAP(NONE) clause requires that 'null' must be listed in a data-sharing attribute, data-mapping attribute, or is_device_ptr clause
+            ptr => null()
+    !$omp end target
+end subroutine defaultmap_builtin_none
+
+module pro
+ implicit none
+contains
+
+ function test_procedure() result(ret)
+    integer :: ret
+    ret = 1
+ end function test_procedure
+
+! Verify we do not catch a function symbol in defaultmap(none)
+! but do catch procedure pointers
+subroutine defaultmap_func_and_procedure_pointer()
+    implicit none
+    procedure(test_procedure), pointer :: f1
+    integer :: i
+
+    f1 => test_procedure
+
+    !$omp target defaultmap(none) map(i)
+!ERROR: The DEFAULTMAP(NONE) clause requires that 'f1' must be listed in a data-sharing attribute, data-mapping attribute, or is_device_ptr clause
+        i = f1()
+        i = test_procedure()
+    !$omp end target
+end subroutine defaultmap_func_and_procedure_pointer
+end module

[agozillon]

Small ping for a review on this if possible please!

[mjklemm]

LGTM

[agozillon]

thank you very much for the quick review @mjklemm