From patchwork Wed Oct 18 09:01:20 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Walfred Tedeschi X-Patchwork-Id: 23665 Received: (qmail 16446 invoked by alias); 18 Oct 2017 09:01:39 -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 15187 invoked by uid 89); 18 Oct 2017 09:01:38 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-23.8 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_LAZY_DOMAIN_SECURITY, RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=Independent X-HELO: mga01.intel.com Received: from mga01.intel.com (HELO mga01.intel.com) (192.55.52.88) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 18 Oct 2017 09:01:31 +0000 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Oct 2017 02:01:29 -0700 X-ExtLoop1: 1 Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga003.jf.intel.com with ESMTP; 18 Oct 2017 02:01:25 -0700 Received: from ulvlx001.iul.intel.com (ulvlx001.iul.intel.com [172.28.207.17]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id v9I91NAd014662; Wed, 18 Oct 2017 10:01:23 +0100 Received: from ulvlx001.iul.intel.com (localhost [127.0.0.1]) by ulvlx001.iul.intel.com with ESMTP id v9I91NL8031299; Wed, 18 Oct 2017 11:01:23 +0200 Received: (from wtedesch@localhost) by ulvlx001.iul.intel.com with LOCAL id v9I91N1d031295; Wed, 18 Oct 2017 11:01:23 +0200 From: Walfred Tedeschi To: palves@redhat.com, simon.marchi@polymtl.ca Cc: gdb-patches@sourceware.org, Walfred Tedeschi Subject: [PATCH V4] symlookup: improves symbol lookup when a file is specified. Date: Wed, 18 Oct 2017 11:01:20 +0200 Message-Id: <1508317280-31265-1-git-send-email-walfred.tedeschi@intel.com> X-IsSubscribed: yes The provided patch adds a scope lookup with higher priority in the case a file is provided for the evaluation. Usual symbol lookup from GDB follows linker logic. This is what is desired most of the time. In the usage case presented a full qualified scope is provided, so the lookup has to follow this priority. Failing in finding the symbol at this scope usual path is followed. As use and test case it is presented two shared objects having a global variable with the same name but comming from different source files. Without the patch evaluating those variables providing the file scope returns the wrong value; It returns the value seen in the first loaded shared object. Using the patch the value defined in the file scope is the one returned. Without using this patch the result of the evaluations are: print 'print-file-var-lib1.c'::this_version_id $1 = 104 and print 'print-file-var-lib2.c'::this_version_id $2 = 104 # This value is wrong we have set 203 in the code With the patch applied we get: print 'print-file-var-lib1.c'::this_version_id $1 = 104 and print 'print-file-var-lib2.c'::this_version_id $2 = 203 # Now value is correct One of the already existing test cases in print-file-var.exp starts to fail after aplying this patch. In fact the value that the linker sees is different then the one debugger can read from the shared object. In this sense it looks like to me that the test has to be changed. The fail is in the call: print 'print-file-var-lib2.c'::this_version_id == v2 in this case v1 and v2 are the same and equal to the this_version_id defined in print-file-var-lib1.c. Test is changed to assure that when the scope operator is used the value seen in print-file-var-lib2.c is the one GDB evaluates, i.e. 203. * Reading again Simon's comments I have decided to take a quick look on the failing test. I have fixed it according to the logic of the current patch. 2017-10-18 Walfred Tedeschi gdb/ChangeLog: * symtab.c (lookup_global_symbol): Add new lookup to ensure priority on given block. gdb/testsuite/ChangeLog: * gdb.base/print-file-var-dlopen-main.c: New file. * gdb.base/print-file-var-dlopen.exp: New test based on print-file-var.exp. * gdb.base/print-file-var-dlopen-lib1.c: New file. * gdb.base/print-file-var-dlopen-lib2.c: New file. * gdb.base/print-file-var.exp: Modify expected result for evaluating 'print-file-var-lib2.c'::this_version_id. --- gdb/symtab.c | 4 + .../gdb.base/print-file-var-dlopen-lib1.c | 25 ++++++ .../gdb.base/print-file-var-dlopen-lib2.c | 25 ++++++ .../gdb.base/print-file-var-dlopen-main.c | 61 +++++++++++++++ gdb/testsuite/gdb.base/print-file-var-dlopen.exp | 90 ++++++++++++++++++++++ gdb/testsuite/gdb.base/print-file-var.exp | 4 +- 6 files changed, 208 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen-main.c create mode 100644 gdb/testsuite/gdb.base/print-file-var-dlopen.exp diff --git a/gdb/symtab.c b/gdb/symtab.c index 16a6b2e..a2c307f 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -2589,6 +2589,10 @@ lookup_global_symbol (const char *name, if (objfile != NULL) result = solib_global_lookup (objfile, name, domain); + /* We still need to look on the global scope of current object file. */ + if (result.symbol == NULL && objfile != NULL) + result = lookup_symbol_in_objfile (objfile, GLOBAL_BLOCK, name, domain); + /* If that didn't work go a global search (of global blocks, heh). */ if (result.symbol == NULL) { diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c new file mode 100644 index 0000000..09ec947 --- /dev/null +++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib1.c @@ -0,0 +1,25 @@ +/* This testcase is part of GDB, the GNU debugger. + Copyright 2012-2017 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 . */ + +int this_version_id = 104; + +int +get_version (void) +{ + static int test; + test = this_version_id; + return test; +} diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c new file mode 100644 index 0000000..b097cd2 --- /dev/null +++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-lib2.c @@ -0,0 +1,25 @@ +/* This testcase is part of GDB, the GNU debugger. + Copyright 2012-2017 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 . */ + +int this_version_id = 203; + +int +get_version (void) +{ + static int test; + test = this_version_id; + return test; +} diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c b/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c new file mode 100644 index 0000000..954a64e --- /dev/null +++ b/gdb/testsuite/gdb.base/print-file-var-dlopen-main.c @@ -0,0 +1,61 @@ +/* This testcase is part of GDB, the GNU debugger. + Copyright 2017 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 . */ + +#include +#include +#include + +int +dummy (void) +{ + return 1; +} + +int +main (void) +{ + int (*get_version1) (void); + int (*get_version2) (void); + int v1, v2; + + void *lib1 = dlopen ("print-file-var-dlopen-lib1.so", RTLD_LAZY); + void *lib2 = dlopen ("print-file-var-dlopen-lib2.so", RTLD_LAZY); + + if (lib1 == NULL || lib2 == NULL) + return 1; + + *(int **) (&get_version1) = dlsym (lib1, "get_version"); + *(int **) (&get_version2) = dlsym (lib2, "get_version"); + + if (get_version1 != NULL + && get_version2 != NULL) + { + v1 = get_version1(); + v2 = get_version2(); + } + + + if (v1 != 104 || v2 != 203) + return 1; + + dummy (); /* STOP */ + + dlclose (lib1); + dlclose (lib2); + + return 0; +} + diff --git a/gdb/testsuite/gdb.base/print-file-var-dlopen.exp b/gdb/testsuite/gdb.base/print-file-var-dlopen.exp new file mode 100644 index 0000000..9c3c0e6 --- /dev/null +++ b/gdb/testsuite/gdb.base/print-file-var-dlopen.exp @@ -0,0 +1,90 @@ +# Copyright 2017 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 . */ + +if {[skip_shlib_tests]} { + return 0 +} + +set executable print-file-var-dlopen-main + +set lib1 "print-file-var-dlopen-lib1" +set lib2 "print-file-var-dlopen-lib2" +set libsrc1 $srcdir/$subdir/${lib1}.c +set libsrc2 $srcdir/$subdir/${lib2}.c +set libobj1 [standard_output_file ${lib1}.so] +set libobj2 [standard_output_file ${lib2}.so] +set lib_dlopen1 [shlib_target_file ${libobj1}] +set lib_dlopen2 [shlib_target_file ${libobj2}] + +set srcfile $srcdir/$subdir/$executable.c +set binfile [standard_output_file $executable] +set shlibdir [standard_output_file {}] + +set lib_opts debug +set exec_opts [list debug shlib_load additional_flags=-DSHLIB_NAME=\"${lib_dlopen1}\" \ +additional_flags=-DSHLIB_NAME2=\"${lib_dlopen2}\"] + +if { [gdb_compile_shlib $libsrc1 $libobj1 $lib_opts] != "" + || [gdb_compile_shlib $libsrc2 $libobj2 $lib_opts] != "" + || [gdb_compile $srcfile $binfile executable $exec_opts] != ""} { + untested "failed to compile" + return -1 +} + +clean_restart $executable + +if ![runto_main] { + untested "could not run to main" + return -1 +} + +# Create to shared libraries having the symbol "this_version_id" defined in both +# libraries global scope. Main program will dllopen one by one and evaluate the +# symbol "this_version_id" via a function provided by the library assigning the value of +# "this_version_id" to V1 and V2. +# Using the scope to perform the evaluations should return the value +# defined in the c file. + +# To avoid adding target-specific code in this testcase, the program +# sets two local variable named 'v1' and 'v2' with the value of +# our global variables. This allows us to compare the value that +# GDB returns for each query against the actual value seen by +# the program itself. + +# Get past the initialization of variables 'v1' and 'v2'. + +set bp_location \ + [gdb_get_line_number "STOP" "${executable}.c"] +gdb_test "break $executable.c:$bp_location" \ + "Breakpoint \[0-9\]+ at 0x\[0-9a-fA-F\]+: .*" \ + "breapoint past v1 & v2 initialization" + +gdb_continue_to_breakpoint "continue to the STOP" + +# Now check the value of this_version_id in both print-file-var-lib1.c +# and print-file-var-lib2.c. + +gdb_test "print 'print-file-var-dlopen-lib1.c'::this_version_id == v1" \ + " = 1" + +gdb_test "print 'print-file-var-dlopen-lib2.c'::this_version_id == v2" \ + " = 1" + +gdb_test "print 'print-file-var-dlopen-lib2.c'::get_version::test == v2" \ + " = 1" + +gdb_test "print 'print-file-var-dlopen-lib1.c'::get_version::test == v1" \ + " = 1" + diff --git a/gdb/testsuite/gdb.base/print-file-var.exp b/gdb/testsuite/gdb.base/print-file-var.exp index 223a67d..ae5071a 100644 --- a/gdb/testsuite/gdb.base/print-file-var.exp +++ b/gdb/testsuite/gdb.base/print-file-var.exp @@ -88,5 +88,7 @@ gdb_test "continue" \ gdb_test "print 'print-file-var-lib1.c'::this_version_id == v1" \ " = 1" -gdb_test "print 'print-file-var-lib2.c'::this_version_id == v2" \ +# Independent of the linker value seen in the second library should +# be 203. +gdb_test "print 'print-file-var-lib2.c'::this_version_id == 203" \ " = 1"