From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15794 invoked by alias); 31 Oct 2018 09:09:46 -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 15773 invoked by uid 89); 31 Oct 2018 09:09:45 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 31 Oct 2018 09:09:42 +0000 Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id AE18454095; Wed, 31 Oct 2018 09:09:40 +0000 (UTC) Subject: Re: [PATCH][gdb/symtab] Fix language of duplicate static minimal symbol To: Keith Seitz , gdb-patches@sourceware.org References: <20181030191142.GA13785@delia> <07e42727-0d74-7f04-ef7c-39e180f71da8@redhat.com> From: Tom de Vries Message-ID: Date: Wed, 31 Oct 2018 09:09:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <07e42727-0d74-7f04-ef7c-39e180f71da8@redhat.com> Content-Type: multipart/mixed; boundary="------------0CB52D523365E1769DEFA058" X-IsSubscribed: yes X-SW-Source: 2018-10/txt/msg00738.txt.bz2 This is a multi-part message in MIME format. --------------0CB52D523365E1769DEFA058 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-length: 2922 On 10/30/18 10:21 PM, Keith Seitz wrote: > On 10/30/18 12:11 PM, Tom de Vries wrote: >> However, when we use gdb to print info on foo, both foos are listed, but we >> get one symbol mangled and one symbol demangled: >> ... >> $ gdb ./a.out -batch -ex "info func foo" >> All functions matching regular expression "foo": >> >> Non-debugging symbols: >> 0x00000000004004c7 foo() >> 0x00000000004004dd _ZL3foov >> ... >> > > Good catch! > >> Build and reg-tested on x86_64-linux. >> >> OK for trunk? > > I have just a few comments. > >> 2018-10-30 Tom de Vries >> >> * symtab.c (symbol_set_names): Call symbol_find_demangled_name >> unconditionally, to get the language of the symbol. > > s/get/set/ ? When reading the patch, I originally wondered how that would help, > but symbol_find_demangled_name actually *sets* the gsymbol's language if > it is language_auto. > Typo fixed. >> >> * gdb.base/msym.c: New test. >> * gdb.base/msym.exp: New file. >> * gdb.base/msym_main.c: New test. > > These entries should be listed under the testsuite ChangeLog, like: > > testsuite/ChangeLog: > YYYY-MM-DD .... > > * gdb.xyz/file1.c: ... > * gdb.xyz/file1.exp: .... > > [https://sourceware.org/gdb/wiki/ContributionChecklist#Properly_Formatted_GNU_ChangeLog] > I have a pre-commit script (for both gcc and gdb) that uses this format, and puts ChangeLog hunks in the correct ChangeLog file ( more detail here: https://sourceware.org/ml/gdb-patches/2018-06/msg00351.html ). Sofar this format has been acceptable for maintainers. > "msym.c" et al aren't particularly descriptive, though. Can we devise a better, > more explicit name? Something along the lines of "multiple-language-msyms.exp". > It's long, but it describes things better. [I'm not saying you should use > this name, but something other than just "msym.{c,exp}".] > Renamed to msym-lang.exp et al. > Sorry, some of that is kinda nitpicky. > Np, I'm still kinda new to gdb, all input appreciated. >> diff --git a/gdb/symtab.c b/gdb/symtab.c >> index cd27a75e8c..481428f733 100644 >> --- a/gdb/symtab.c >> +++ b/gdb/symtab.c >> @@ -818,6 +818,10 @@ symbol_set_names (struct general_symbol_info *gsymbol, >> else >> linkage_name_copy = linkage_name; >> >> + /* Set the symbol language. */ >> + char *demangled_name = symbol_find_demangled_name (gsymbol, >> + linkage_name_copy); >> + >> entry.mangled = linkage_name_copy; >> slot = ((struct demangled_name_entry **) >> htab_find_slot (per_bfd->demangled_names_hash, > > symbol_find_demangled_name returns a malloc'd string which will leak here unless > the code goes through the branch. You'll need to save the result into a > unique_xmalloc_ptr and adjust the code accordingly. > Done, thanks for pointing that out. > Otherwise, LGTM. Thanks very much for the patch. > And thanks for the review. Re-tested as attached. Thanks, - Tom --------------0CB52D523365E1769DEFA058 Content-Type: text/x-patch; name="0001-gdb-symtab-Fix-language-of-duplicate-static-minimal-symbol.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-gdb-symtab-Fix-language-of-duplicate-static-minimal-sym"; filename*1="bol.patch" Content-length: 6998 [gdb/symtab] Fix language of duplicate static minimal symbol Consider a test-case with source files msym.c: ... static int foo (void) { return 1; } ... and msym_main.c: ... static int foo (void) { return 2; } int main (void) { return 0; } .. compiled as c++ with minimal symbols: ... $ g++ msym_main.c msym.c ... With objdump -x we find the two foo symbols prefixed with their corresponding files in the symbol table: ... 0000000000000000 l df *ABS* 0000000000000000 msym_main.c 00000000004004c7 l F .text 000000000000000b _ZL3foov 0000000000000000 l df *ABS* 0000000000000000 msym.c 00000000004004dd l F .text 000000000000000b _ZL3foov ... However, when we use gdb to print info on foo, both foos are listed, but we get one symbol mangled and one symbol demangled: ... $ gdb ./a.out -batch -ex "info func foo" All functions matching regular expression "foo": Non-debugging symbols: 0x00000000004004c7 foo() 0x00000000004004dd _ZL3foov ... During minimal symbol reading symbol_set_names is called for each symbol. First, it's called with foo from msym.c, an entry is created in per_bfd->demangled_names_hash and symbol_find_demangled_name is called, which has the side effect of setting the language of the symbol to language_cplus. Then, it's called with foo from msym_main.c. Since per_bfd->demangled_names_hash already has an entry for that name, symbol_find_demangled_name is not called, and the language of the symbol remains language_auto. Fix this by doing the symbol_find_demangled_name call unconditionally. Build and reg-tested on x86_64-linux. 2018-10-30 Tom de Vries * symtab.c (symbol_set_names): Call symbol_find_demangled_name unconditionally, to set the language of the symbol. Manage freeing returned pointer using gdb::unique_xmalloc_ptr. * gdb.base/msym-lang.c: New test. * gdb.base/msym-lang.exp: New file. * gdb.base/msym-lang-main.c: New test. --- gdb/symtab.c | 14 +++++++------- gdb/testsuite/gdb.base/msym-lang-main.c | 28 ++++++++++++++++++++++++++++ gdb/testsuite/gdb.base/msym-lang.c | 22 ++++++++++++++++++++++ gdb/testsuite/gdb.base/msym-lang.exp | 25 +++++++++++++++++++++++++ 4 files changed, 82 insertions(+), 7 deletions(-) diff --git a/gdb/symtab.c b/gdb/symtab.c index cd27a75e8c..aee4c0c710 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -818,6 +818,11 @@ symbol_set_names (struct general_symbol_info *gsymbol, else linkage_name_copy = linkage_name; + /* Set the symbol language. */ + char *demangled_name_ptr + = symbol_find_demangled_name (gsymbol, linkage_name_copy); + gdb::unique_xmalloc_ptr demangled_name (demangled_name_ptr); + entry.mangled = linkage_name_copy; slot = ((struct demangled_name_entry **) htab_find_slot (per_bfd->demangled_names_hash, @@ -830,9 +835,7 @@ symbol_set_names (struct general_symbol_info *gsymbol, || (gsymbol->language == language_go && (*slot)->demangled[0] == '\0')) { - char *demangled_name = symbol_find_demangled_name (gsymbol, - linkage_name_copy); - int demangled_len = demangled_name ? strlen (demangled_name) : 0; + int demangled_len = demangled_name ? strlen (demangled_name.get ()) : 0; /* Suppose we have demangled_name==NULL, copy_name==0, and linkage_name_copy==linkage_name. In this case, we already have the @@ -870,10 +873,7 @@ symbol_set_names (struct general_symbol_info *gsymbol, } if (demangled_name != NULL) - { - strcpy ((*slot)->demangled, demangled_name); - xfree (demangled_name); - } + strcpy ((*slot)->demangled, demangled_name.get()); else (*slot)->demangled[0] = '\0'; } diff --git a/gdb/testsuite/gdb.base/msym-lang-main.c b/gdb/testsuite/gdb.base/msym-lang-main.c new file mode 100644 index 0000000000..f093f71ca4 --- /dev/null +++ b/gdb/testsuite/gdb.base/msym-lang-main.c @@ -0,0 +1,28 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2018 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 . */ + +static int +foo (void) +{ + return 2; +} + +int +main (void) +{ + return 0; +} diff --git a/gdb/testsuite/gdb.base/msym-lang.c b/gdb/testsuite/gdb.base/msym-lang.c new file mode 100644 index 0000000000..c9610154dd --- /dev/null +++ b/gdb/testsuite/gdb.base/msym-lang.c @@ -0,0 +1,22 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2018 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 . */ + +static int +foo (void) +{ + return 1; +} diff --git a/gdb/testsuite/gdb.base/msym-lang.exp b/gdb/testsuite/gdb.base/msym-lang.exp new file mode 100644 index 0000000000..993225c9d6 --- /dev/null +++ b/gdb/testsuite/gdb.base/msym-lang.exp @@ -0,0 +1,25 @@ +# Copyright (C) 2018 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 . + +standard_testfile msym-lang-main.c msym-lang.c + +if {[prepare_for_testing "failed to prepare" $testfile [list $srcfile $srcfile2] \ + {c++}]} { + return -1 +} + +clean_restart ${testfile} + +gdb_test "info func foo" ".* foo\\(\\).* foo\\(\\).*" --------------0CB52D523365E1769DEFA058--