From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29697 invoked by alias); 11 Dec 2013 20:38:13 -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 29687 invoked by uid 89); 11 Dec 2013 20:38:13 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 X-HELO: homiemail-a94.g.dreamhost.com Received: from caibbdcaaaaf.dreamhost.com (HELO homiemail-a94.g.dreamhost.com) (208.113.200.5) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 11 Dec 2013 20:38:11 +0000 Received: from homiemail-a94.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a94.g.dreamhost.com (Postfix) with ESMTP id 7F7D938A06F; Wed, 11 Dec 2013 12:38:10 -0800 (PST) Received: from redwood.eagercon.com (c-50-148-128-197.hsd1.ca.comcast.net [50.148.128.197]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: eager@eagerm.com) by homiemail-a94.g.dreamhost.com (Postfix) with ESMTPSA id 4899738A059; Wed, 11 Dec 2013 12:38:10 -0800 (PST) Message-ID: <52A8CD31.5090809@eagerm.com> Date: Wed, 11 Dec 2013 20:38:00 -0000 From: Michael Eager User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: gdb-patches ml CC: Keith Seitz Subject: [PATCH] Regression setting breakpoint Content-Type: multipart/mixed; boundary="------------010302000400070901030002" X-IsSubscribed: yes X-SW-Source: 2013-12/txt/msg00454.txt.bz2 This is a multi-part message in MIME format. --------------010302000400070901030002 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-length: 2009 There is a regression when setting a breakpoint which was introduced in gdb-7.3 by a fix in this patch: https://sourceware.org/ml/gdb-patches/2010-03/msg00220.html The regression shows up in C when the linkage name is different from the internal symbol name. For example, void goo (int b) asm("_goo"); void goo (int b) {} will create a function with the linkage name of "_goo" and the DWARF will describe the source name of "goo". There is both a DW_AT_name and DW_AT_linkage_name in the DIE for this function. Some compilers (e.g., ICC) have options allowing linkage names to have characters prepended to the source name so that the linkage name is different from the source name and can not be computed from it. Prior to this patch, a breakpoint at "_goo" would find the linkage symbol, and one at "goo" would find the source symbol. After the patch, the source name is replace with the linkage name. The attached patch fixes this by making die_needs_namespace() return 0 for any C language program. There's also a test case. I'm not sure that this is the right fix for the problem, although I'm pretty sure that it should not break anything. There is code in dwarf2_compute_name() which only calls die_needs_namespace() for C++, Java, or Fortran programs, which could be moved into die_needs_namespace(). Possibly the fix should be in dwarf2_physname() where the call to die_needs_namespace() is done before the check for DW_AT_linkage_name is done. Comment: Much of the code in dwarf2_compute_name(), dwarf2_physname(), and related functions seems complex, convoluted, and confusing (the big Three C's). The source name for a symbol is not the same as the fully qualified name and it's not the same as the linkage name. That a language supports FQNs with namespaces does not seem to me to say that this should have anything to do with what the linkage (aka physical) name for the symbol is. -- Michael Eager eager@eagercon.com 1960 Park Blvd., Palo Alto, CA 94306 650-325-8077 --------------010302000400070901030002 Content-Type: text/x-patch; name="0001-Fix-regression-symbol-name-different-from-linkage-na.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-Fix-regression-symbol-name-different-from-linkage-na.pa"; filename*1="tch" Content-length: 3643 >From 6e6a7110f950e3d90978637b21fcb913934be9b1 Mon Sep 17 00:00:00 2001 From: Michael Eager Date: Tue, 10 Dec 2013 11:50:27 -0800 Subject: [PATCH] Fix regression symbol name different from linkage name. gdb: * dwarf2read.c (die_needs_namespace): Do nothing for C language. testsuite: * gdb.base/break-linker-symname.c: New. * gdb.base/break-linker-symname.exp: New. --- gdb/dwarf2read.c | 3 ++ gdb/testsuite/gdb.base/break-linker-symname.c | 28 +++++++++++++++++++++++ gdb/testsuite/gdb.base/break-linker-symname.exp | 25 ++++++++++++++++++++ 3 files changed, 56 insertions(+), 0 deletions(-) create mode 100644 gdb/testsuite/gdb.base/break-linker-symname.c create mode 100644 gdb/testsuite/gdb.base/break-linker-symname.exp diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 3974d0b..d2a236c 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -8044,6 +8044,9 @@ die_needs_namespace (struct die_info *die, struct dwarf2_cu *cu) { struct attribute *attr; + if (cu->language == language_c) + return 0; + switch (die->tag) { case DW_TAG_namespace: diff --git a/gdb/testsuite/gdb.base/break-linker-symname.c b/gdb/testsuite/gdb.base/break-linker-symname.c new file mode 100644 index 0000000..8728ea1 --- /dev/null +++ b/gdb/testsuite/gdb.base/break-linker-symname.c @@ -0,0 +1,28 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2013 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 . */ + +void goo (int b) asm("_goo"); + +void goo (int b) +{ +} + +int main (void) +{ + goo (4); + return 0; +} diff --git a/gdb/testsuite/gdb.base/break-linker-symname.exp b/gdb/testsuite/gdb.base/break-linker-symname.exp new file mode 100644 index 0000000..2a86f37 --- /dev/null +++ b/gdb/testsuite/gdb.base/break-linker-symname.exp @@ -0,0 +1,25 @@ +# Copyright 2013 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 . + +# Test that 'set breakpoint always-inserted 1' is not a brick +# Also verifies that breakpoint enabling/disabling works properly +# with duplicated breakpoints. + +if { [prepare_for_testing break-linker-symname.exp break-linker-symname break-linker-symname.c] } { + return -1 +} + +gdb_test "break _goo" "Breakpoint 1.*" "set breakpoint on linker symbol" +gdb_test "break goo" "Breakpoint 2.*" "set breakpoint on source symbol" -- 1.7.1 --------------010302000400070901030002--