[flang-commits] [flang] [Flang][OpenMP] Fix implicit symbol resolution for USE-renamed arrays (PR #189215)

[Aditya Trivedi via flang-commits]

https://github.com/adit4443ya updated https://github.com/llvm/llvm-project/pull/189215

>From eb1f3ee9b1eeb7c7e0da3766864a0e2f7f148abb Mon Sep 17 00:00:00 2001
From: Aditya Trivedi <adit4443ya at gmail.com>
Date: Thu, 4 Jun 2026 19:14:24 +0530
Subject: [PATCH]   [Flang][OpenMP] Fix USE-renamed array DSA in OpenMP regions

  When a module array is imported with a local alias via USE renaming
  (e.g. USE mod, ONLY: s_ary => ary), CreateImplicitSymbols was calling
  GetUltimate() which bypassed the alias and returned the original module
  symbol. This caused the OpenMP scope to create a host-association under
  the wrong name (ary instead of s_ary), producing a rank-mismatch
  error when two modules both exported a symbol named ary with different
  ranks.

  Fix by passing the USE-alias symbol directly instead of its ultimate,
  so the host-association is created under the local alias name. Also
  remove the assert in DeclareNewAccessEntity that was overly strict
  since the scope is always passed explicitly to MakeAssocSymbol.

  Fixes #185344
---
 flang/lib/Semantics/resolve-directives.cpp    |  7 ++--
 .../Semantics/OpenMP/use-rename-array-dsa.f90 | 32 +++++++++++++++++++
 2 files changed, 35 insertions(+), 4 deletions(-)
 create mode 100644 flang/test/Semantics/OpenMP/use-rename-array-dsa.f90

diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index 821724fedc7d4..5538a8a3c28c2 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -1128,7 +1128,6 @@ const parser::DoConstruct *DirectiveAttributeVisitor<T>::GetDoConstructIf(
 template <typename T>
 Symbol *DirectiveAttributeVisitor<T>::DeclareNewAccessEntity(
     const Symbol &object, Symbol::Flag flag, Scope &scope) {
-  assert(object.owner() != currScope());
   auto &symbol{MakeAssocSymbol(object.name(), object, scope)};
   symbol.set(flag);
   if (flag == Symbol::Flag::OmpCopyIn) {
@@ -2561,7 +2560,7 @@ void OmpAttributeVisitor::CreateImplicitSymbols(
     // privatized in p2 and its privatization in p1 to be skipped.
     auto makeSymbol = [&](Symbol::Flags flags) {
       const Symbol *hostSymbol =
-          lastDeclSymbol ? lastDeclSymbol : &symbol->GetUltimate();
+          lastDeclSymbol ? lastDeclSymbol : symbol;
       assert(flags.LeastElement());
       Symbol::Flag flag = *flags.LeastElement();
       lastDeclSymbol = DeclareNewAccessEntity(
@@ -2572,8 +2571,8 @@ void OmpAttributeVisitor::CreateImplicitSymbols(
     auto useLastDeclSymbol = [&]() {
       if (lastDeclSymbol) {
         const Symbol *hostSymbol =
-            lastDeclSymbol ? lastDeclSymbol : &symbol->GetUltimate();
-        MakeAssocSymbol(symbol->name(), *hostSymbol,
+            lastDeclSymbol ? lastDeclSymbol : symbol;
+        MakeAssocSymbol(hostSymbol->name(), *hostSymbol,
             context_.FindScope(dirContext.directiveSource));
       }
     };
diff --git a/flang/test/Semantics/OpenMP/use-rename-array-dsa.f90 b/flang/test/Semantics/OpenMP/use-rename-array-dsa.f90
new file mode 100644
index 0000000000000..865cdff2eeb24
--- /dev/null
+++ b/flang/test/Semantics/OpenMP/use-rename-array-dsa.f90
@@ -0,0 +1,32 @@
+! RUN: %flang_fc1 -fdebug-dump-symbols -fopenmp %s | FileCheck %s
+
+! Verify that a USE-renamed array (s_ary => ary) is correctly associated in an
+! OpenMP region under the alias name, not the original module name.
+! Regression test for https://github.com/llvm/llvm-project/issues/185344
+
+module use_rename_mod1
+  implicit none
+  real(8), allocatable :: ary(:,:,:)
+end module
+
+module use_rename_mod2
+  implicit none
+  real(8), allocatable :: ary(:,:,:,:,:)
+end module
+
+program test
+  use use_rename_mod1, only: s_ary => ary
+  use use_rename_mod2, only: ary
+  implicit none
+  integer(4) :: i
+
+  !$omp parallel do
+    do i = 1, 10
+      s_ary(i,1,1) = ary(i,1,1,1,1)
+    end do
+  !$omp end parallel do
+end program
+! The loop variable is private and predetermined.
+! CHECK: i (OmpPrivate, OmpPreDetermined): HostAssoc
+! The OMP region must create a host-association for s_ary under its alias name.
+! CHECK: s_ary (OmpShared): HostAssoc