http://sourceware.org/ml/gdb-patches/2014-08/msg00025.html

Subject: [patch 1/2] Re: Crash regression(?) printing Fortran strings in bt  [Re: [V2 00/23] Fortran dynamic array support]

--FCuugMFkClbJLl1L

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On Fri, 01 Aug 2014 09:20:19 +0200, Keven Boell wrote:

> I just tried it on Fedora 20 i686.  Applied the patch, you mentioned, on top of

> the Fortran VLA series and executed your dynamic-other-frame test.  Everything

> is working fine here, I cannot reproduce the crash.

I have it reproducible on Fedora 20 i686 with plain

CFLAGS=-g ./configure;make;cd gdb/testsuite;make site.exp;runtest gdb.fortran/dynamic-other-frame.exp

Besides that I have updated the testcase with

	gdb_test_no_output "set print frame-arguments all"

so that there is no longer needed the patch:

	[patch] Display Fortran strings in backtraces

	https://sourceware.org/ml/gdb-patches/2014-07/msg00709.html

The fix below has no regressions for me.  Unfortunately I do not see why you

cannot reproduce it.

Thanks,

Jan

--- ./gdb/dwarf2loc.c	2016-08-29 04:01:25.000000000 +0200

+++ ./gdb/dwarf2loc.c	2016-09-01 11:00:20.258909494 +0200

@@ -2289,6 +2289,15 @@ const struct dwarf_expr_context_funcs dw

   dwarf_expr_get_obj_addr

 };

+static void

+select_frame_cleanup (void *arg)

+{

+  struct frame_info *frame = (struct frame_info *) arg;

+

+  if (frame != NULL)

+    select_frame (frame);

+}

+

 /* Evaluate a location description, starting at DATA and with length

    SIZE, to find the current location of variable of TYPE in the

    context of FRAME.  BYTE_OFFSET is applied after the contents are

@@ -2318,6 +2327,11 @@ dwarf2_evaluate_loc_desc_full (struct ty

   ctx = new_dwarf_expr_context ();

   old_chain = make_cleanup_free_dwarf_expr_context (ctx);

+

+  make_cleanup (select_frame_cleanup, deprecated_safe_get_selected_frame ());

+  if (frame != NULL)

+    select_frame (frame);

+

   value_chain = make_cleanup_value_free_to_mark (value_mark ());

   ctx->gdbarch = get_objfile_arch (objfile);

Index: gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame-stub.f90

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame-stub.f90	2015-05-31 16:14:05.844545344 +0200

@@ -0,0 +1,24 @@

+! Copyright 2010 Free Software Foundation, Inc.

+!

+! This program is free software; you can redistribute it and/or modify

+! it under the terms of the GNU General Public License as published by

+! the Free Software Foundation; either version 2 of the License, or

+! (at your option) any later version.

+!

+! This program is distributed in the hope that it will be useful,

+! but WITHOUT ANY WARRANTY; without even the implied warranty of

+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+! GNU General Public License for more details.

+!

+! You should have received a copy of the GNU General Public License

+! along with this program; if not, write to the Free Software

+! Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

+!

+! Ihis file is the Fortran source file for dynamic.exp.

+! Original file written by Jakub Jelinek <jakub@redhat.com>.

+! Modified for the GDB testcase by Jan Kratochvil <jan.kratochvil@redhat.com>.

+

+subroutine bar

+  real :: dummy

+  dummy = 1

+end subroutine bar

Index: gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame.exp

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame.exp	2015-05-31 16:14:05.845545351 +0200

@@ -0,0 +1,39 @@

+# Copyright 2010 Free Software Foundation, Inc.

+

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 2 of the License, or

+# (at your option) any later version.

+# 

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+# 

+# You should have received a copy of the GNU General Public License

+# along with this program; if not, write to the Free Software

+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  

+

+set testfile "dynamic-other-frame"

+set srcfile1 ${testfile}.f90

+set srcfile2 ${testfile}-stub.f90

+set objfile2 [standard_output_file ${testfile}-stub.o]

+set executable ${testfile}

+set binfile [standard_output_file ${executable}]

+

+if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${objfile2}" object {f90}] != ""

+     || [gdb_compile "${srcdir}/${subdir}/${srcfile1} ${objfile2}" "${binfile}" executable {debug f90}] != "" } {

+    untested "Couldn't compile ${srcfile1} or ${srcfile2}"

+    return -1

+}

+

+clean_restart ${executable}

+

+gdb_test_no_output "set print frame-arguments all"

+

+if ![runto bar_] then {

+    perror "couldn't run to bar_"

+    continue

+}

+

+gdb_test "bt" {foo \(string='hello'.*}

Index: gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame.f90

===================================================================

--- /dev/null	1970-01-01 00:00:00.000000000 +0000

+++ gdb-7.9.50.20150520/gdb/testsuite/gdb.fortran/dynamic-other-frame.f90	2015-05-31 16:14:05.845545351 +0200

@@ -0,0 +1,36 @@

+! Copyright 2010 Free Software Foundation, Inc.

+!

+! This program is free software; you can redistribute it and/or modify

+! it under the terms of the GNU General Public License as published by

+! the Free Software Foundation; either version 2 of the License, or

+! (at your option) any later version.

+!

+! This program is distributed in the hope that it will be useful,

+! but WITHOUT ANY WARRANTY; without even the implied warranty of

+! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+! GNU General Public License for more details.

+!

+! You should have received a copy of the GNU General Public License

+! along with this program; if not, write to the Free Software

+! Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

+!

+! Ihis file is the Fortran source file for dynamic.exp.

+! Original file written by Jakub Jelinek <jakub@redhat.com>.

+! Modified for the GDB testcase by Jan Kratochvil <jan.kratochvil@redhat.com>.

+

+subroutine foo (string)

+  interface

+    subroutine bar

+    end subroutine

+  end interface

+  character string*(*)

+  call bar                                ! stop-here

+end subroutine foo

+program test

+  interface

+    subroutine foo (string)

+    character string*(*)

+    end subroutine

+  end interface

+  call foo ('hello')

+end