[flang][OpenMP] Fix sections lastprivate for common blocks

[luporl]

Common block handling was missing in sections' lastprivate lowering.

Fixes #121719

[llvmbot]

@llvm/pr-subscribers-flang-openmp

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

Author: Leandro Lupori (luporl)

Changes

Common block handling was missing in sections' lastprivate lowering.

Fixes #121719

---

Full diff: https://github.com/llvm/llvm-project/pull/125504.diff

2 Files Affected:

• (modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+7-1)
• (modified) flang/test/Lower/OpenMP/sections.f90 (+18-1)

diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index 25595d2ea6c7d8..01ad9eff166003 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -2089,7 +2089,13 @@ genSectionsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
       const auto &objList = std::get<ObjectList>(lastp->t);
       for (const Object &object : objList) {
         semantics::Symbol *sym = object.sym();
-        converter.copyHostAssociateVar(*sym, &insp, /*hostIsSource=*/false);
+        if (const auto *common =
+                sym->detailsIf<semantics::CommonBlockDetails>()) {
+          for (const auto &obj : common->objects())
+            converter.copyHostAssociateVar(*obj, &insp, /*hostIsSource=*/false);
+        } else {
+          converter.copyHostAssociateVar(*sym, &insp, /*hostIsSource=*/false);
+        }
       }
     }
   }
diff --git a/flang/test/Lower/OpenMP/sections.f90 b/flang/test/Lower/OpenMP/sections.f90
index 22879185286352..5900eef6ea2802 100644
--- a/flang/test/Lower/OpenMP/sections.f90
+++ b/flang/test/Lower/OpenMP/sections.f90
@@ -2,7 +2,7 @@
 
 ! This test checks the lowering of OpenMP sections construct with several clauses present
 
-! RUN: %flang_fc1 -flang-experimental-hlfir -emit-hlfir %openmp_flags %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-hlfir %openmp_flags %s -o - | FileCheck %s
 ! RUN: bbc -hlfir -emit-hlfir %openmp_flags %s -o - | FileCheck %s
 
 !CHECK: func @_QQmain() attributes {fir.bindc_name = "sample"} {
@@ -263,6 +263,23 @@ subroutine lastprivate2()
     !$omp end sections
 end subroutine
 
+!CHECK-LABEL: func @_QPlastprivate_common
+!CHECK: %[[I:.*]]:2 = hlfir.declare %{{.*}} {uniq_name = "_QFlastprivate_commonEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+!CHECK: %[[I_PRIV:.*]]:2 = hlfir.declare %{{.*}} {uniq_name = "_QFlastprivate_commonEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+!CHECK: omp.sections
+!CHECK: omp.section
+!CHECK: %[[TMP:.*]] = fir.load %[[I_PRIV]]#0 : !fir.ref<i32>
+!CHECK: hlfir.assign %[[TMP]] to %[[I]]#0 : i32, !fir.ref<i32>
+subroutine lastprivate_common()
+    integer :: i
+    common /com/ i
+
+    i = 1
+    !$omp sections lastprivate(/com/)
+        i = 2
+    !$omp end sections
+end subroutine
+
 !CHECK-LABEL: func @_QPunstructured_sections_privatization
 subroutine unstructured_sections_privatization()
 !CHECK: %[[X:.*]] = fir.alloca f32 {bindc_name = "x", uniq_name = "_QFunstructured_sections_privatizationEx"}

[ergawy]

LGTM! Thanks!

[tblah]

Thanks!

I was surprised this is allowed by the standard but it appears it is.