From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21433 invoked by alias); 21 Oct 2015 09:49:43 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 21421 invoked by uid 89); 21 Oct 2015 09:49:42 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Wed, 21 Oct 2015 09:49:41 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 42A139246B; Wed, 21 Oct 2015 09:49:40 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t9L9nc5m020493; Wed, 21 Oct 2015 05:49:39 -0400 Message-ID: <56275FB2.3050509@redhat.com> Date: Wed, 21 Oct 2015 10:39:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Aleksandar Ristovski , gdb-patches@sourceware.org Subject: Re: [PATCH 2/2] [nto] Improve ABI sniffing. References: <5621218D.6070801@redhat.com> <1445364649-12175-1-git-send-email-aristovski@qnx.com> <1445364649-12175-3-git-send-email-aristovski@qnx.com> In-Reply-To: <1445364649-12175-3-git-send-email-aristovski@qnx.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-10/txt/msg00390.txt.bz2 On 10/20/2015 07:10 PM, Aleksandar Ristovski wrote: > Use qnx specific notes to figure out the OS. > > gdb/ChangeLog: > * gdb/nto-tdep.c (QNX_NOTE_NAME, QNX_INFO_SECT_NAME): New defines. > (nto_sniff_abi_note_section): New function. > (nto_elf_osabi_sniffer): Use new function to recognize nto specific > binary. > --- > gdb/nto-tdep.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 44 insertions(+), 2 deletions(-) > > diff --git a/gdb/nto-tdep.c b/gdb/nto-tdep.c > index e50d302..48826cb 100644 > --- a/gdb/nto-tdep.c > +++ b/gdb/nto-tdep.c > @@ -32,6 +32,9 @@ > #include "gdbcore.h" > #include "objfiles.h" > > +#define QNX_NOTE_NAME "QNX" > +#define QNX_INFO_SECT_NAME "QNX_info" > + > #ifdef __CYGWIN__ > #include > #endif > @@ -332,12 +335,51 @@ nto_dummy_supply_regset (struct regcache *regcache, char *regs) > /* Do nothing. */ > } > > +static void > +nto_sniff_abi_note_section (bfd *abfd, asection *sect, void *obj) > +{ > + const char *sectname; > + unsigned int sectsize; > + char *note; // buffer holding the section contents Please use /**/ format for comments, and write full sentences - start with uppercase, period at end. Usually that leads to putting the comment above, e.g.: + /* Buffer holding the section contents. */ + char *note; > + unsigned int namelen; > + const char *name; > + > + sectname = bfd_get_section_name (abfd, sect); > + sectsize = bfd_section_size (abfd, sect); > + > + /* TODO: limit the note size here, for now limit is 128 bytes > + (enough to check the name and type). */ This reads like limiting is left to do, but then it does implement a limit. So this TODO comment is confusing. You should also make sure the section is the at least the minimum size you expect though. > + if (sectsize > 128) > + sectsize = 128; > + > + if (sectname && strstr (sectname, QNX_INFO_SECT_NAME) != NULL) > + *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO; > + sectname != NULL > + if (sectname && strstr (sectname, "note") != NULL) sectname != NULL > + { > + note = alloca (sectsize); For C++, write: note = (char *) alloca (sectsize); > + bfd_get_section_contents (abfd, sect, note, 0, sectsize); > + namelen = (unsigned int) bfd_h_get_32 (abfd, note); > + name = note + 12; > + > + if (namelen > 0 > + && (0 == strcmp (name, QNX_NOTE_NAME))) > + *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO; > + } > +} > + > enum gdb_osabi > nto_elf_osabi_sniffer (bfd *abfd) > { > - if (nto_is_nto_target) > + enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; > + > + bfd_map_over_sections (abfd, > + nto_sniff_abi_note_section, > + &osabi); > + > + if (osabi == GDB_OSABI_UNKNOWN && nto_is_nto_target) > return nto_is_nto_target (abfd); ... nto_is_nto_target = procfs_is_nto_target; ... static enum gdb_osabi procfs_is_nto_target (bfd *abfd) { return GDB_OSABI_QNXNTO; } So that basically could be rewritten as: if (osabi == GDB_OSABI_UNKNOWN && nto_is_nto_target) return GDB_OSABI_QNXNTO; But, do we still need this nto_is_nto_target hack here? Now with proper sniffing, can't we just remove it altogether? > - return GDB_OSABI_UNKNOWN; > + return osabi; > } > > static const char *nto_thread_state_str[] = > Thanks, Pedro Alves