RE: [PATCH 1/1] gdb, infcmd: Support jump command with same line in multiple object files.

["Puputti, Matti" <matti.puputti@intel.com>]

Hi Bruno,

Thank you for your comments.
I will create a new patch to address these comments. Will submit this afternoon.

Br,
Matti Puputti

> -----Original Message-----
> From: Bruno Larsen <blarsen@redhat.com>
> Sent: Thursday, April 13, 2023 4:33 PM
> To: Puputti, Matti <matti.puputti@intel.com>; gdb-patches@sourceware.org
> Subject: Re: [PATCH 1/1] gdb, infcmd: Support jump command with same
> line in multiple object files.
> 
> On 08/03/2023 14:26, Matti Puputti via Gdb-patches wrote:
> > If the jump target is found in multiple object files, select the one in
> > the current object file.
> 
> Hi, thanks for working on this. I think this is a reasonable change, but
> I have some comments.
> 
> First, I think your cover letter description makes for a better commit
> message than the one you provided here. Also, you say "object file" but
> use symtab in the code. Each symtab is related to a compilation unit,
> and an objfile can have multiple compilation units. I think bit more
> precise in the language would be nice :)
> 
> > ---
> >   gdb/infcmd.c                       | 14 ++++++-
> >   gdb/testsuite/gdb.base/jump2.c     | 29 +++++++++++++++
> >   gdb/testsuite/gdb.base/jump2.exp   | 59
> ++++++++++++++++++++++++++++++
> >   gdb/testsuite/gdb.base/jump2.h     | 30 +++++++++++++++
> >   gdb/testsuite/gdb.base/jump2_foo.c | 24 ++++++++++++
> >   5 files changed, 155 insertions(+), 1 deletion(-)
> >   create mode 100755 gdb/testsuite/gdb.base/jump2.c
> >   create mode 100755 gdb/testsuite/gdb.base/jump2.exp
> >   create mode 100755 gdb/testsuite/gdb.base/jump2.h
> >   create mode 100755 gdb/testsuite/gdb.base/jump2_foo.c
> >
> > diff --git a/gdb/infcmd.c b/gdb/infcmd.c
> > index c369b795757..1b91562f137 100644
> > --- a/gdb/infcmd.c
> > +++ b/gdb/infcmd.c
> > @@ -1080,7 +1080,19 @@ jump_command (const char *arg, int from_tty)
> >     std::vector<symtab_and_line> sals
> >       = decode_line_with_last_displayed (arg, DECODE_LINE_FUNFIRSTLINE);
> >     if (sals.size () != 1)
> > -    error (_("Unreasonable jump request"));
> > +    {
> > +      /* If multiple sal-objects were found, try dropping those that aren't
> > +	 from the current objectfile.  */
> > +      sals.erase (std::remove_if (sals.begin (), sals.end (),
> > +		  [] (symtab_and_line &sal)
> > +		    {
> > +		      struct symtab_and_line cursal
> > +			  = get_current_source_symtab_and_line ();
> > +		      return sal.symtab != cursal.symtab;
> > +		    }), sals.end ());
> > +      if (sals.size () != 1)
> > +	error (_("Unreasonable jump request"));
> > +    }
> >
> >     symtab_and_line &sal = sals[0];
> >
> > diff --git a/gdb/testsuite/gdb.base/jump2.c
> b/gdb/testsuite/gdb.base/jump2.c
> > new file mode 100755
> > index 00000000000..468838a9d1a
> > --- /dev/null
> > +++ b/gdb/testsuite/gdb.base/jump2.c
> I think that a more descriptive name, like jump_multiple_objfiles, would
> be better.
> > @@ -0,0 +1,29 @@
> > +/* This testcase is part of GDB, the GNU debugger.
> > +
> > +   Copyright 2021-2023 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 3 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, see <http://www.gnu.org/licenses/>.
> */
> > +
> > +#include "jump2.h"
> > +
> > +extern int foo (int n);
> > +
> > +
> > +int main ()
> 
> the coding guidelines ask that this be:
> 
> int
> 
> main ()
> 
> > +{
> > +  int n = foo (1);
> > +  bar (n);
> > +
> > +  return 0;
> > +}
> > diff --git a/gdb/testsuite/gdb.base/jump2.exp
> b/gdb/testsuite/gdb.base/jump2.exp
> > new file mode 100755
> > index 00000000000..f6bc29dfe1c
> > --- /dev/null
> > +++ b/gdb/testsuite/gdb.base/jump2.exp
> > @@ -0,0 +1,59 @@
> > +#   Copyright 2021-2023 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 3 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, see <http://www.gnu.org/licenses/>.
> */
> > +#
> > +# Tests GDBs support for jump, when the source line is in multiple
> > +# object files.
> > +
> > +
> > +standard_testfile .c
> > +set srcfile2 jump2_foo.c
> > +set srcfile3 jump2.h
> > +
> > +
> > +if { [prepare_for_testing "failed to prepare" $testfile \
> > +      [list ${srcfile} ${srcfile2}]] } {
> > +    return -1
> > +}
> > +
> > +if { ![runto_main] } {
> > +    perror "couldn't run to breakpoint"
> > +    return -1
> > +}
> > +
> > +
> > +set bar_first_line [gdb_get_line_number "bar-first-line" ${srcfile3}]
> > +set bar_middle_line [gdb_get_line_number "bar-middle-line" ${srcfile3}]
> > +set bar_last_line [gdb_get_line_number "bar-last-line" ${srcfile3}]
> > +
> > +
> > +# Set breakpoints in the function bar.  Executable has two object files,
> > +# and both have a copy of the same source lines.  Therefore breakpoints
> > +# will have two locations.
> > +gdb_test "break ${srcfile3}:${bar_first_line}" \
> > +    "Breakpoint.* at .*${srcfile3}:${bar_first_line}\\\. \\\(2 locations\\\)"
> > +gdb_test "break ${srcfile3}:${bar_last_line}" \
> > +    "Breakpoint.* at .*${srcfile3}:${bar_last_line}\\\. \\\(2 locations\\\)"
> 
> You can simplify this by using gdb_breakpoint, which is also more
> resilient that manually setting the breakpoint message.
> 
> I also tested locally and seen no regressions, but I'd like to see my
> comments changed before giving my tag
> 
> --
> Cheers,
> Bruno
> 
> > +
> > +# Run to the breakpoint in bar.
> > +gdb_continue_to_breakpoint "bar_first_line" \
> > +    ".*${srcfile3}:${bar_first_line}.*"
> > +
> > +# Jump within the function.  Debugger shall be able to jump, even if the
> > +# target line is in two different object files.  After jump, we will hit
> > +# the breakpoint at the last line of bar.
> > +gdb_test "jump ${bar_middle_line}"  [multi_line \
> > +    "Continuing at ($hex).*" \
> > +    "Breakpoint ${decimal}.* at .*${srcfile3}:${bar_last_line}.*"] \
> > +    "Jump within the objectfile"
> > diff --git a/gdb/testsuite/gdb.base/jump2.h
> b/gdb/testsuite/gdb.base/jump2.h
> > new file mode 100755
> > index 00000000000..5e3849cb3cb
> > --- /dev/null
> > +++ b/gdb/testsuite/gdb.base/jump2.h
> > @@ -0,0 +1,30 @@
> > +/* Copyright (C) 2021-2023 Free Software Foundation, Inc.
> > +
> > +   This file is part of GDB.
> > +
> > +   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 3 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, see <http://www.gnu.org/licenses/>.
> */
> > +
> > +#ifndef JUMP2_H
> > +#define JUMP2_H
> > +
> > +static int
> > +bar (int n)
> > +{
> > +  int retval = n;
> > +  retval += 1;      /* bar-first-line */
> > +  retval *= -1;     /* bar-middle-line */
> > +  return retval;    /* bar-last-line */
> > +}
> > +
> > +#endif /* JUMP2_H */
> > diff --git a/gdb/testsuite/gdb.base/jump2_foo.c
> b/gdb/testsuite/gdb.base/jump2_foo.c
> > new file mode 100755
> > index 00000000000..667f2398551
> > --- /dev/null
> > +++ b/gdb/testsuite/gdb.base/jump2_foo.c
> > @@ -0,0 +1,24 @@
> > +/* This testcase is part of GDB, the GNU debugger.
> > +
> > +   Copyright 2021-2023 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 3 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, see <http://www.gnu.org/licenses/>.
> */
> > +
> > +#include "jump2.h"
> > +
> > +int
> > +foo (int n)
> > +{
> > +  return bar (n);
> > +}

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