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Re: Problems while debugging fortran
On Thu, Sep 20, 2007 at 01:46:22PM -0700, Joel Brobecker wrote:
> > No, just "break <linenumber>". However, I tried your command and it
> > worked. Why? Shouldn't the behavior be the same in both cases?
>
> It should be the same if the "current file" is set to test.f.
> It looks like it isn't. For some reason, GDB thinks that the current
> file is something else. Again, perhaps a copy of your GDB session
> might give a clue.
Here's a relevant patch from the Debian packages of GDB. As you can
see it comes from a mailing list message - I don't remember exactly
who submitted it without looking it up and I don't remember exactly
why it was never committed, but it was probably Wu Zhou and it was
probably never merged because of the larger issue of symbol case
sensitivity.
--
Daniel Jacobowitz
CodeSourcery
Daniel,
Although the proper way of adding case insensitivity to symbol lookup is
still under discussion, I think it might be desirable to set the main
function of Fortran programs to "MAIN__" first. Because it can at least
let GDB recognize that the language is Fortran after loading a Fortran
executable only. What is your idea on this? Please comments. TIA!
Here is the patch to set the main function in Fortran programs to
"MAIN__". And followed is a patch to verify this. Tested with g77 and
gfortran on x86, and g77 on ppc64. With the first patch, it reported
PASS; without, report FAIL. No regression is found in gdb.fortran
testcases.
P.S: if there is a symbol named "MAIN__" in sources of other languages, it
might disturb the debugging. But I am not sure how much it is.
---
gdb/symtab.c | 8 +++++--
gdb/testsuite/gdb.fortran/lang.exp | 40 +++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+), 2 deletions(-)
Index: gdb/symtab.c
===================================================================
--- gdb/symtab.c.orig 2007-01-27 20:35:18.000000000 -0500
+++ gdb/symtab.c 2007-01-27 20:35:34.000000000 -0500
@@ -4189,8 +4189,12 @@ find_main_name (void)
}
/* The languages above didn't identify the name of the main procedure.
- Fallback to "main". */
- set_main_name ("main");
+ Fallback to "MAIN__" (g77 and gfortran) if we can find it in the
+ minimal symtab, to "main" otherwise. */
+ if (lookup_minimal_symbol ("MAIN__", NULL, NULL))
+ set_main_name ("MAIN__");
+ else
+ set_main_name ("main");
}
char *
Index: gdb/testsuite/gdb.fortran/lang.exp
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb/testsuite/gdb.fortran/lang.exp 2007-01-27 20:35:34.000000000 -0500
@@ -0,0 +1,40 @@
+# Copyright 2005 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 Wu Zhou. (woodzltc@cn.ibm.com)
+
+# This file is part of the gdb testsuite. It is intended to test that gdb
+# could recognize the Fortran language after loading the binary
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set testfile "array-element"
+set srcfile ${srcdir}/${subdir}/${testfile}.f
+set binfile ${objdir}/${subdir}/${testfile}
+
+if { [gdb_compile "${srcfile}" "${binfile}" executable {debug f77}] != "" } {
+ untested "Couldn't compile ${srcfile}"
+ return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+gdb_test "show language" ".*currently fortran.*" "show language(fortran)"