Both bug6-alloc-self-component-ice.f90 and
bug17-final-rank-overload-ice.f90 fail with:
12 | end program ! Seg fault at trans-decl.cc:1697
| 1
internal compiler error: Segmentation fault
0x1f5d97f internal_error(char const*, ...)
../../gcc/gcc/diagnostic-global-context.cc:787
0xc219bf crash_signal
../../gcc/gcc/toplev.cc:325
0x5dff99 gfc_get_symbol_decl(gfc_symbol*)
../../gcc/gcc/fortran/trans-decl.cc:1676
The fix is trivial - guard against calling gfc_allocate_pdt_comp
without sym->param_list.
Passes regtesting on FC44/x86_64. OK for mainline.
Cheers
Paul
From 07409c4ff4ce21c613abbeb4c211b20e76dbb355 Mon Sep 17 00:00:00 2001
From: Paul Thomas <[email protected]>
Date: Thu, 8 Oct 2026 11:39:06 +0100
Subject: [PATCH] Fortran: [meta-bug] [PDT] Parameterized derived type errors
[PR82173]
2026-10-06 Paul Thomas <[email protected]>
gcc/fortran
PR fortran/82173
* trans-decl.cc (gfc_trans_deferred_vars): gfc_init_default_pdt
cannot be called unless the symbol has a param_list.
gcc/testsuite/
PR fortran/82173
* gfortran.dg/pdt_bug6.f90: New test.
* gfortran.dg/pdt_bug17.f90: New test.
---
gcc/fortran/trans-decl.cc | 3 +-
gcc/testsuite/gfortran.dg/pdt_bug17.f90 | 39 +++++++++++++++++++++++++
gcc/testsuite/gfortran.dg/pdt_bug6.f90 | 12 ++++++++
3 files changed, 53 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gfortran.dg/pdt_bug17.f90
create mode 100644 gcc/testsuite/gfortran.dg/pdt_bug6.f90
diff --git a/gcc/fortran/trans-decl.cc b/gcc/fortran/trans-decl.cc
index a614e71eced..02c4c72259d 100644
--- a/gcc/fortran/trans-decl.cc
+++ b/gcc/fortran/trans-decl.cc
@@ -5161,7 +5161,8 @@ gfc_trans_deferred_vars (gfc_symbol * proc_sym, gfc_wrapped_block * block)
if (!sym->attr.dummy && !sym->attr.pointer)
{
tmp = gfc_init_default_pdt (sym, true);
- if (!sym->attr.allocatable && tmp == NULL_TREE)
+ if (!sym->attr.allocatable && tmp == NULL_TREE
+ && sym->param_list)
{
tmp = gfc_allocate_pdt_comp (sym->ts.u.derived,
sym->backend_decl,
diff --git a/gcc/testsuite/gfortran.dg/pdt_bug17.f90 b/gcc/testsuite/gfortran.dg/pdt_bug17.f90
new file mode 100644
index 00000000000..2f76ae33289
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pdt_bug17.f90
@@ -0,0 +1,39 @@
+! { dg-do run }
+! See attachment to PR82173 comment 10 - reproducers/bug17-final-rank-overload-ice.f90
+module mm
+ type :: t(k, n)
+ integer, kind :: k = 4
+ integer, len :: n = 1
+ real(k) :: v(n)
+ contains
+ final :: fin4, fin8, fin4_r1
+ end type
+ integer :: tally = 0
+contains
+ subroutine fin4 (a)
+ type(t(4, *)), intent(inout) :: a
+ tally = tally + 1
+ end subroutine
+ subroutine fin8 (a)
+ type(t(8, *)), intent(inout) :: a
+ tally = tally + 10
+ end subroutine
+ subroutine fin4_r1 (a)
+ type(t(4, *)), intent(inout) :: a(:)
+ tally = tally + 100
+ end subroutine
+end module ! Segmentation fault here
+
+ use mm
+ call foo
+! Each final routine is called twice - assignment and leaving scope
+ if (tally /= 222) stop 1
+contains
+ subroutine foo
+ type(t(4, 2)) :: a, b(2)
+ type(t(8, 2)) :: c
+ a = t(4, 2)([1.0,2.0])
+ b = [t(4, 2)([1.0,2.0]), t(4, 2)([3.0,4.0])]
+ c = t(8, 2)([1.0,2.0])
+ end
+end
diff --git a/gcc/testsuite/gfortran.dg/pdt_bug6.f90 b/gcc/testsuite/gfortran.dg/pdt_bug6.f90
new file mode 100644
index 00000000000..3fa573e9189
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pdt_bug6.f90
@@ -0,0 +1,12 @@
+! { dg-do run }
+! See attachment to PR82173 comment 10 - reproducers/bug6-alloc-self-component-ice.f90
+program g2
+ type :: node(n)
+ integer, len :: n = 1
+ real :: v(n)
+ type(node(:)), allocatable :: owned
+ end type
+ type(node(3)) :: head
+ head%v = 1.0
+ if (allocated (head%owned)) stop 1
+end program ! Seg fault at trans-decl.cc:1697
--
2.55.0
