Dear all,
I am submitting the attached simple - and obvious - patch on
behalf of Paul. It prevents a resource exhaustion due to an
infinite loop, and has been regtested by multiple contributers, ;-)
at least on x86_64-pc-linux-gnu.
I intend to commit it to mainline within 24 hours, unless
there are further comments.
Thanks,
Harald
From 01254aa2eb766c7584fd047568d7277d4d65d067 Mon Sep 17 00:00:00 2001
From: Paul Thomas
Date: Fri, 9 Dec 2022 22:13:45 +0100
Subject: [PATCH] Fortran: ICE on recursive derived types with allocatable
components [PR107872]
gcc/fortran/ChangeLog:
PR fortran/107872
* resolve.cc (derived_inaccessible): Skip over allocatable components
to prevent an infinite loop.
gcc/testsuite/ChangeLog:
PR fortran/107872
* gfortran.dg/pr107872.f90: New test.
---
gcc/fortran/resolve.cc | 3 +-
gcc/testsuite/gfortran.dg/pr107872.f90 | 40 ++
2 files changed, 42 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gfortran.dg/pr107872.f90
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 75dc4b59105..158bf08ec26 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -7536,7 +7536,8 @@ derived_inaccessible (gfc_symbol *sym)
for (c = sym->components; c; c = c->next)
{
/* Prevent an infinite loop through this function. */
- if (c->ts.type == BT_DERIVED && c->attr.pointer
+ if (c->ts.type == BT_DERIVED
+ && (c->attr.pointer || c->attr.allocatable)
&& sym == c->ts.u.derived)
continue;
diff --git a/gcc/testsuite/gfortran.dg/pr107872.f90 b/gcc/testsuite/gfortran.dg/pr107872.f90
new file mode 100644
index 000..09838479e92
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107872.f90
@@ -0,0 +1,40 @@
+! { dg-do run }
+!
+! Test the fix for PR107872, where an ICE occurred in
+! resolve.cc(derived_inaccessible) because derived types with
+! recursive allocatable components were not catered for.
+!
+module mod1
+ type t
+ integer :: data
+ type(t), allocatable :: next
+ contains
+ procedure, private :: write_t
+ generic :: write(formatted) => write_t
+ end type
+contains
+ recursive subroutine write_t(this, unit, iotype, v_list, iostat, iomsg)
+class(t), intent(in) :: this
+integer, intent(in) :: unit
+character(*), intent(in) :: iotype
+integer, intent(in) :: v_list(:)
+integer, intent(out) :: iostat
+character(*), intent(inout) :: iomsg
+if (ALLOCATED(this%next)) &
+ write (unit, '(dt)') this%next
+write (unit, '(i2)') this%data
+ end subroutine
+end module
+
+ use mod1
+ type(t) :: a
+ character (8) :: buffer
+ a%data = 1
+ allocate (a%next)
+ a%next%data = 2
+ allocate (a%next%next)
+ a%next%next%data = 3
+ write (buffer, '(dt)')a
+ deallocate (a%next)
+ if (trim (buffer) .ne. ' 3 2 1') stop 1
+end
--
2.35.3