* [PATCH][gdb/symtab] Handle DW_AT_string_length with location list
@ 2021-10-14 19:58 Tom de Vries
2021-10-15 15:22 ` Simon Marchi
0 siblings, 1 reply; 4+ messages in thread
From: Tom de Vries @ 2021-10-14 19:58 UTC (permalink / raw)
To: gdb-patches; +Cc: Jan Kratochvil
Hi,
Consider a fortran routine where a string variable s is modified:
...
subroutine f(s)
character*(*) s
print *, s
s(1:3) = 'oof'
print *, s
end subroutine f
...
When compiling with optimization level -O1 and printing the type of
variable s we get:
...
$ gdb -q -batch outputs/gdb.opt/fortran-string/fortran-string \
-ex "b f" \
-ex run \
-ex "ptype s"
Breakpoint 1 at 0x4006f7: file fortran-string.f90, line 21.
Breakpoint 1, f (s=..., _s=_s@entry=3) at fortran-string.f90:21
21 subroutine f(s)
type = character*1
...
while with -O0 we have instead:
...
type = character (3)
...
The problem is that the type of s is:
...
<1><2d6>: Abbrev Number: 21 (DW_TAG_string_type)
<2d7> DW_AT_string_length: 0xbf (location list)
<2db> DW_AT_byte_size : 4
...
where the DW_AT_string_length is a location list, a case that is not handled
by attr_to_dynamic_prop.
Fix this by handling attr->form_is_section_offset () in attr_to_dynamic_prop.
Tested on x86_64-linux.
The test-case is based on gdb.opt/fortran-string.exp from
https://src.fedoraproject.org/rpms/gdb/raw/f32/f/gdb-archer-vla-tests.patch .
I've updated the copyrights to stretch to 2021.
[ I've tried to create a dwarf assembly test-case for this, but didn't
manage. ]
Co-Authored-By: Jan Kratochvil <jan.kratochvil@redhat.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26910
Any comments?
Thanks,
- Tom
[gdb/symtab] Handle DW_AT_string_length with location list
---
gdb/dwarf2/read.c | 24 +++++++++++++++----
gdb/testsuite/gdb.opt/fortran-string.exp | 41 ++++++++++++++++++++++++++++++++
gdb/testsuite/gdb.opt/fortran-string.f90 | 32 +++++++++++++++++++++++++
3 files changed, 93 insertions(+), 4 deletions(-)
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index cbd9a3012eb..0477a689d54 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -18468,14 +18468,30 @@ attr_to_dynamic_prop (const struct attribute *attr, struct die_info *die,
}
else if (attr->form_is_constant ())
prop->set_const_val (attr->constant_value (0));
- else
+ else if (attr->form_is_section_offset ())
{
- dwarf2_invalid_attrib_class_complaint (dwarf_form_name (attr->form),
- dwarf2_name (die, cu));
- return 0;
+ switch (attr->name)
+ {
+ case DW_AT_string_length:
+ baton = XOBNEW (obstack, struct dwarf2_property_baton);
+ baton->property_type = default_type;
+ fill_in_loclist_baton (cu, &baton->loclist, attr);
+ prop->set_loclist (baton);
+ gdb_assert (prop->baton () != NULL);
+ break;
+ default:
+ goto invalid;
+ }
}
+ else
+ goto invalid;
return 1;
+
+ invalid:
+ dwarf2_invalid_attrib_class_complaint (dwarf_form_name (attr->form),
+ dwarf2_name (die, cu));
+ return 0;
}
/* See read.h. */
diff --git a/gdb/testsuite/gdb.opt/fortran-string.exp b/gdb/testsuite/gdb.opt/fortran-string.exp
new file mode 100644
index 00000000000..62de48cf9d7
--- /dev/null
+++ b/gdb/testsuite/gdb.opt/fortran-string.exp
@@ -0,0 +1,41 @@
+# Copyright 2009-2021 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.
+
+# This file was written by Jan Kratochvil <jan.kratochvil@redhat.com>.
+
+# Test GDB can cope with Fortran strings having their length present in a CPU
+# register. With -O0 the string length is passed on the stack. To make this
+# test meaningful the follow assertion should pass. It is not being checked
+# here as the "_s" symbol is compiler dependent:
+# (gdb) info address _s
+# Symbol "_s" is a variable in register XX.
+
+standard_testfile .f90
+
+if { [prepare_for_testing "prepare for testing" ${testfile} ${srcfile} \
+ {debug f90 additional_flags=-O1}] } {
+ return -1
+}
+
+if ![runto f] then {
+ perror "couldn't run to f"
+ continue
+}
+
+gdb_test_no_output "set print frame-arguments all"
+gdb_test "frame" ".*s='foo'.*"
+gdb_test "ptype s" "type = character \\(3\\)"
+gdb_test "p s" "\\$\[0-9\]* = 'foo'"
diff --git a/gdb/testsuite/gdb.opt/fortran-string.f90 b/gdb/testsuite/gdb.opt/fortran-string.f90
new file mode 100644
index 00000000000..0a316b2dc79
--- /dev/null
+++ b/gdb/testsuite/gdb.opt/fortran-string.f90
@@ -0,0 +1,32 @@
+! Copyright 2009-2021 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 f(s)
+ character*(*) s
+ print *, s
+ s(1:3) = 'oof'
+ print *, s
+end subroutine f
+
+program main
+ character*3 s;
+ s = 'foo'
+ call f (s)
+end program main
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][gdb/symtab] Handle DW_AT_string_length with location list
2021-10-14 19:58 [PATCH][gdb/symtab] Handle DW_AT_string_length with location list Tom de Vries
@ 2021-10-15 15:22 ` Simon Marchi
2021-10-15 16:08 ` Tom de Vries
2021-10-28 8:44 ` Tom de Vries
0 siblings, 2 replies; 4+ messages in thread
From: Simon Marchi @ 2021-10-15 15:22 UTC (permalink / raw)
To: Tom de Vries, gdb-patches; +Cc: Jan Kratochvil
On 2021-10-14 3:58 p.m., Tom de Vries via Gdb-patches wrote:
> Hi,
>
> Consider a fortran routine where a string variable s is modified:
> ...
> subroutine f(s)
> character*(*) s
> print *, s
> s(1:3) = 'oof'
> print *, s
> end subroutine f
> ...
>
> When compiling with optimization level -O1 and printing the type of
> variable s we get:
> ...
> $ gdb -q -batch outputs/gdb.opt/fortran-string/fortran-string \
> -ex "b f" \
> -ex run \
> -ex "ptype s"
> Breakpoint 1 at 0x4006f7: file fortran-string.f90, line 21.
>
> Breakpoint 1, f (s=..., _s=_s@entry=3) at fortran-string.f90:21
> 21 subroutine f(s)
> type = character*1
I'm not familiar with fortran, does this notation ("character*1") have a
meaning in fortran?
Again, I don't know anything about fortran, but the change in dwarf2/read.c
looks good to me.
Simon
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][gdb/symtab] Handle DW_AT_string_length with location list
2021-10-15 15:22 ` Simon Marchi
@ 2021-10-15 16:08 ` Tom de Vries
2021-10-28 8:44 ` Tom de Vries
1 sibling, 0 replies; 4+ messages in thread
From: Tom de Vries @ 2021-10-15 16:08 UTC (permalink / raw)
To: Simon Marchi, gdb-patches; +Cc: Jan Kratochvil
On 10/15/21 5:22 PM, Simon Marchi wrote:
> On 2021-10-14 3:58 p.m., Tom de Vries via Gdb-patches wrote:
>> Hi,
>>
>> Consider a fortran routine where a string variable s is modified:
>> ...
>> subroutine f(s)
>> character*(*) s
>> print *, s
>> s(1:3) = 'oof'
>> print *, s
>> end subroutine f
>> ...
>>
>> When compiling with optimization level -O1 and printing the type of
>> variable s we get:
>> ...
>> $ gdb -q -batch outputs/gdb.opt/fortran-string/fortran-string \
>> -ex "b f" \
>> -ex run \
>> -ex "ptype s"
>> Breakpoint 1 at 0x4006f7: file fortran-string.f90, line 21.
>>
>> Breakpoint 1, f (s=..., _s=_s@entry=3) at fortran-string.f90:21
>> 21 subroutine f(s)
>> type = character*1
>
> I'm not familiar with fortran, does this notation ("character*1") have a
> meaning in fortran?
>
I'm not very familiar with fortran either, but AFAIU the meaning is:
character string of length one.
> Again, I don't know anything about fortran, but the change in dwarf2/read.c
> looks good to me.
Thanks for the review.
- Tom
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][gdb/symtab] Handle DW_AT_string_length with location list
2021-10-15 15:22 ` Simon Marchi
2021-10-15 16:08 ` Tom de Vries
@ 2021-10-28 8:44 ` Tom de Vries
1 sibling, 0 replies; 4+ messages in thread
From: Tom de Vries @ 2021-10-28 8:44 UTC (permalink / raw)
To: Simon Marchi, gdb-patches; +Cc: Jan Kratochvil
On 10/15/21 5:22 PM, Simon Marchi wrote:
> On 2021-10-14 3:58 p.m., Tom de Vries via Gdb-patches wrote:
>> Hi,
>>
>> Consider a fortran routine where a string variable s is modified:
>> ...
>> subroutine f(s)
>> character*(*) s
>> print *, s
>> s(1:3) = 'oof'
>> print *, s
>> end subroutine f
>> ...
>>
>> When compiling with optimization level -O1 and printing the type of
>> variable s we get:
>> ...
>> $ gdb -q -batch outputs/gdb.opt/fortran-string/fortran-string \
>> -ex "b f" \
>> -ex run \
>> -ex "ptype s"
>> Breakpoint 1 at 0x4006f7: file fortran-string.f90, line 21.
>>
>> Breakpoint 1, f (s=..., _s=_s@entry=3) at fortran-string.f90:21
>> 21 subroutine f(s)
>> type = character*1
>
> I'm not familiar with fortran, does this notation ("character*1") have a
> meaning in fortran?
>
> Again, I don't know anything about fortran, but the change in dwarf2/read.c
> looks good to me.
I've reviewed the test-case once more, and did the following updates:
- removed the "contributed by" lines in the test-case, since we no
longer do that.
( https://sourceware.org/gdb/wiki/ContributionChecklist#Attribution )
- updated the copyright license version to gplv3, and replaced the
snailmail pointer to copy of license with the url.
Committed with those changes (too trivial to repost).
Thanks,
- Tom
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-10-28 8:44 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-14 19:58 [PATCH][gdb/symtab] Handle DW_AT_string_length with location list Tom de Vries
2021-10-15 15:22 ` Simon Marchi
2021-10-15 16:08 ` Tom de Vries
2021-10-28 8:44 ` Tom de Vries
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).