[flang-commits] [flang] [flang][openmp] initialize allocatable components of firstprivate copies (PR #121808)

[via flang-commits]

https://github.com/jeanPerier created https://github.com/llvm/llvm-project/pull/121808

Descriptors of allocatable components of firstprivate derived type copies need to be set-up. Otherwise the program later die when manipulating them inside OpenMP region.

>From 6a95d5c4ed418011a5d28e4dd76c1a94c3a4b1ba Mon Sep 17 00:00:00 2001
From: Jean Perier <jperier at nvidia.com>
Date: Mon, 6 Jan 2025 09:25:22 -0800
Subject: [PATCH] [flang][openmp] initialize allocatable components of
 firstprivate copies

---
 flang/lib/Lower/Bridge.cpp                    |  6 +++++-
 .../Lower/OpenMP/firstprivate-alloc-comp.f90  | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 flang/test/Lower/OpenMP/firstprivate-alloc-comp.f90

diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index c7bf4248155483..37f51d74d23f8f 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -833,7 +833,11 @@ class FirConverter : public Fortran::lower::AbstractConverter {
           if_builder.end();
         },
         [&](const auto &) -> void {
-          if (skipDefaultInit)
+          // Always initialize allocatable component descriptor, even when the
+          // value is later copied from the host (e.g. firstprivate) because the
+          // assignment from the host to the copy will fail if the component
+          // descriptors are not initialized.
+          if (skipDefaultInit && !hlfir::mayHaveAllocatableComponent(hSymType))
             return;
           // Initialize local/private derived types with default
           // initialization (Fortran 2023 section 11.1.7.5 and OpenMP 5.2
diff --git a/flang/test/Lower/OpenMP/firstprivate-alloc-comp.f90 b/flang/test/Lower/OpenMP/firstprivate-alloc-comp.f90
new file mode 100644
index 00000000000000..2453fe2c5208bc
--- /dev/null
+++ b/flang/test/Lower/OpenMP/firstprivate-alloc-comp.f90
@@ -0,0 +1,19 @@
+! Test delayed privatization for derived types with allocatable components.
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -o - %s | FileCheck %s
+
+subroutine firstprivate_alloc_comp
+  type t1
+    integer, allocatable :: c(:)
+  end type
+  type(t1) :: x
+  !$omp parallel firstprivate(x)
+    print *, allocated(x%c)
+  !$omp end parallel
+end
+
+  call firstprivate_alloc_comp()
+end
+! CHECK-LABEL:   omp.private {type = firstprivate} @_QFfirstprivate_alloc_compEx_firstprivate_ref_rec__QFfirstprivate_alloc_compTt1 : !fir.ref<!fir.type<_QFfirstprivate_alloc_compTt1{c:!fir.box<!fir.heap<!fir.array<?xi32>>>}>> alloc {
+! CHECK:     fir.call @_FortranAInitialize(
+! CHECK:   } copy {
+! ...