From patchwork Wed Aug 19 20:02:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 8308 Received: (qmail 116585 invoked by alias); 19 Aug 2015 20:02:24 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 116576 invoked by uid 89); 19 Aug 2015 20:02:23 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.6 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=no 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, 19 Aug 2015 20:02:22 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 3C30DA9A; Wed, 19 Aug 2015 20:02:21 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t7JK2Je6004171; Wed, 19 Aug 2015 16:02:20 -0400 Message-ID: <55D4E0CB.7070404@redhat.com> Date: Wed, 19 Aug 2015 21:02:19 +0100 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Luis Machado , Doug Evans CC: gdb-patches@sourceware.org Subject: Re: [PATCH] Fix language of compilation unit with unknown file extension (Re: [PATCH] Guard compile tests from running when unsupported + harden feature support check) References: <1439988825-19754-1-git-send-email-lgustavo@codesourcery.com> <55D48179.2030000@redhat.com> <55D485D1.8040802@codesourcery.com> <55D48891.7050808@redhat.com> <55D4C47F.6080902@codesourcery.com> <55D4DF8C.1000408@redhat.com> In-Reply-To: <55D4DF8C.1000408@redhat.com> On 08/19/2015 08:57 PM, Pedro Alves wrote: > On 08/19/2015 07:01 PM, Luis Machado wrote: >> It could be either a GDB bug for not honoring the language in the DIE >> itself or a testcase issue for not naming the source file with the >> correct language extension. > > I think it's a GDB bug. See patch below. I had left some unnecessary bits in the test's assembly (copy/paste, and then insufficient trimming). Here's a leaner version. --- From 8451d7202d4126bfaec5a49fe555989b6fd9b2b1 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Wed, 19 Aug 2015 20:52:44 +0100 Subject: [PATCH] Fix language of compilation unit with unknown file extension Here, in dwarfread.c:process_full_comp_unit: /* Set symtab language to language from DW_AT_language. If the compilation is from a C file generated by language preprocessors, do not set the language if it was already deduced by start_subfile. */ if (!(cu->language == language_c && COMPUNIT_FILETABS (cust)->language != language_c)) COMPUNIT_FILETABS (cust)->language = cu->language; in case start_subfile doesn't manage to deduce a language COMPUNIT_FILETABS(cust)->language ends up as language_unknown, not language_c. So the condition above evals false and we never set the language from the cu's language. gdb/ChangeLog: 2015-08-19 Pedro Alves * dwarf2read.c (process_full_comp_unit): To tell whether start_subfile managed to deduce a language, test for language_unknown instead of language_c. gdb/testsuite/ChangeLog: 2015-08-19 Pedro Alves * gdb.dwarf2/comp-unit-lang.exp: New file. * gdb.dwarf2/comp-unit-lang.c: New file. --- gdb/dwarf2read.c | 2 +- gdb/testsuite/gdb.dwarf2/comp-unit-lang.c | 34 ++++++++++++ gdb/testsuite/gdb.dwarf2/comp-unit-lang.exp | 83 +++++++++++++++++++++++++++++ 3 files changed, 118 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.dwarf2/comp-unit-lang.c create mode 100644 gdb/testsuite/gdb.dwarf2/comp-unit-lang.exp diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 445ad86..92b3982 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -8079,7 +8079,7 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu, compilation is from a C file generated by language preprocessors, do not set the language if it was already deduced by start_subfile. */ if (!(cu->language == language_c - && COMPUNIT_FILETABS (cust)->language != language_c)) + && COMPUNIT_FILETABS (cust)->language != language_unknown)) COMPUNIT_FILETABS (cust)->language = cu->language; /* GCC-4.0 has started to support -fvar-tracking. GCC-3.x still can diff --git a/gdb/testsuite/gdb.dwarf2/comp-unit-lang.c b/gdb/testsuite/gdb.dwarf2/comp-unit-lang.c new file mode 100644 index 0000000..2835209 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/comp-unit-lang.c @@ -0,0 +1,34 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2011-2015 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 . */ + +asm (".section \".text\""); +asm (".balign 8"); +asm ("func_start: .globl func_start"); + +static void +func (void) +{ +} + +asm ("func_end: .globl func_end"); + +int +main (void) +{ + func (); + return 0; +} diff --git a/gdb/testsuite/gdb.dwarf2/comp-unit-lang.exp b/gdb/testsuite/gdb.dwarf2/comp-unit-lang.exp new file mode 100644 index 0000000..9140608 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/comp-unit-lang.exp @@ -0,0 +1,83 @@ +# Copyright 2014-2015 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 GDB determines the frame's language based on the comp +# unit's language, even if the file has an unknown file extension, +# such as ".txt". + +load_lib dwarf.exp + +# This test can only be run on targets which support DWARF-2 and use +# gas. +if {![dwarf2_support]} { + return 0 +} + +standard_testfile .c comp-unit-lang.S + +# Assemble the DWARF using CU_LANG as compilation unit's language. +# Run to a function in that compilation unit and check that GDB +# figures out that the language is GDB_LANG. + +proc do_test {cu_lang gdb_lang} { + global testfile srcfile srcfile2 + + global lang + set lang $cu_lang + + # Make some DWARF for the test. + set asm_file [standard_output_file $srcfile2] + Dwarf::assemble $asm_file { + # Creating a CU with 4-byte addresses lets this test link on + # both 32- and 64-bit machines. + cu { addr_size 4 } { + extern func_start func_end + + global lang + + compile_unit { + {name file1.txt} + {language @$lang} + {low_pc func_start addr} + {high_pc func_end addr} + } { + subprogram { + {external 1 flag} + {name func} + {low_pc func_start addr} + {high_pc func_end addr} + } { + } + } + } + } + + if { [prepare_for_testing "failed to prepare" ${testfile} \ + [list $srcfile $asm_file] {nodebug}] } { + return -1 + } + + if ![runto func] { + return -1 + } + + gdb_test "show language" "\"auto; currently $gdb_lang\".*" +} + +# Some paths in the debugger that built-in fallbacks to C. Check C++ +# as well to make sure the test doesn't happen to work because of such +# a fallback. +do_test DW_LANG_C "c" +do_test DW_LANG_C_plus_plus "c\\+\\+"