From 3ec033fab4ac2e6289b5928f949e054ff89e8ae8 Mon Sep 17 00:00:00 2001 From: Kevin Buettner Date: Thu, 21 Sep 2023 17:58:05 -0700 Subject: [PATCH] gdb/testsuite: Add relative versus absolute LD_LIBRARY_PATH test At one time, circa 2006, there was a bug, which was presumably fixed without adding a test case: If you provided some relative path to the shared library, such as with export LD_LIBRARY_PATH=. then gdb would fail to match the shared library name during the TLS lookup. I think there may have been a bit more to it than is provided by that explanation, since the test also takes care to split the debug info into a separate file. In any case, this commit is based on one of Red Hat's really old local patches. I've attempted to update it and remove a fair amount of cruft, hopefully without losing any critical elements from the test. Testing on Fedora 38 (correctly) shows 1 unsupported test for native-gdbserver and 5 PASSes for the native target as well as native-extended-gdbserver. In his review of v1 of this patch, Lancelot SIX observed that 'thread_local' could be used in place of '__thread' in the C source files. But it only became available via the standard in C11, so I used additional_flags=-std=c11 for compiling both the shared object and the main program. Also, while testing with CC_FOR_TARGET=clang, I found that 'additional_flags=-Wl,-soname=${binsharedbase}' caused clang to complain that this linker flag was unused when compiling the source file, so I moved this linker option to 'ldflags='. My testing for this v2 patch shows the same results as with v1, but I've done additional testing with CC_FOR_TARGET=clang as well. The results are the same as when gcc is used. Co-Authored-by: Jan Kratochvil Reviewed-By: Lancelot Six --- gdb/testsuite/gdb.threads/tls-sepdebug-main.c | 29 ++++++ .../gdb.threads/tls-sepdebug-shared.c | 21 ++++ gdb/testsuite/gdb.threads/tls-sepdebug.exp | 95 +++++++++++++++++++ 3 files changed, 145 insertions(+) create mode 100644 gdb/testsuite/gdb.threads/tls-sepdebug-main.c create mode 100644 gdb/testsuite/gdb.threads/tls-sepdebug-shared.c create mode 100644 gdb/testsuite/gdb.threads/tls-sepdebug.exp diff --git a/gdb/testsuite/gdb.threads/tls-sepdebug-main.c b/gdb/testsuite/gdb.threads/tls-sepdebug-main.c new file mode 100644 index 00000000000..0c0903a0453 --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-sepdebug-main.c @@ -0,0 +1,29 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2006-2023 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 + +/* Note: thread_local requires C11 or later. */ +extern thread_local int var; + +int main() +{ + /* Ensure we link against pthreads even with --as-needed. */ + pthread_testcancel(); + return var; +} diff --git a/gdb/testsuite/gdb.threads/tls-sepdebug-shared.c b/gdb/testsuite/gdb.threads/tls-sepdebug-shared.c new file mode 100644 index 00000000000..c051eb1041d --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-sepdebug-shared.c @@ -0,0 +1,21 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2006-2023 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 + +/* Note: thread_local requires C11 or later. */ +thread_local int var = 42; diff --git a/gdb/testsuite/gdb.threads/tls-sepdebug.exp b/gdb/testsuite/gdb.threads/tls-sepdebug.exp new file mode 100644 index 00000000000..ad67bfd37de --- /dev/null +++ b/gdb/testsuite/gdb.threads/tls-sepdebug.exp @@ -0,0 +1,95 @@ +# Copyright 2006-2023 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 . + +# This test creates a shared library and a main program which uses +# that library, extracts the debug info of the library to a separate +# file, and then tests that a symbol from the shared library is +# accessible using both absolute and relative settings of +# LD_LIBRARY_PATH. + +# This test needs to change the environment in which the test program +# is run, specifically the setting of LD_LIBRARY_PATH. GDB can adjust +# this setting for both native and extended-remote targets, but not +# for targets to which GDB connects after the program has already +# started. Therefore, this test won't work for targets which use +# "target remote". +require !use_gdb_stub +require {have_compile_flag -std=c11} + +set testfile tls-sepdebug +set srcmainfile ${testfile}-main.c +set srcsharedfile ${testfile}-shared.c + +set binmainfile [standard_output_file ${testfile}-main] +set binsharedbase ${testfile}-shared.so +set binsharedfile [standard_output_file ${binsharedbase}] + +# Build the shared library, but use explicit -soname; otherwise the +# full path to the library would get encoded into ${binmainfile} +# making LD_LIBRARY_PATH tests useless. +# +# The compile flag -std=c11 is required because the test case uses +# 'thread_local' to indicate thread local storage. This is available +# as a macro starting in C11 and became a C-language keyword in C23. +if { [gdb_compile_shlib \ + "${srcdir}/${subdir}/${srcsharedfile}" "${binsharedfile}" \ + [list debug \ + ldflags=-Wl,-soname=${binsharedbase} \ + additional_flags=-std=c11]] \ + != "" } { + untested "Couldn't compile test library" + return -1 +} + +# Strip debug information from $binsharedfile, placing it in +# ${binsharedfile}.debug. Also add a .gnu_debuglink in the former, +# pointing to the latter. +gdb_gnu_strip_debug ${binsharedfile} + +# Build main program, but do not use `shlib=' since that would +# automatically add -rpath for gcc. +if { [gdb_compile_pthreads \ + "${srcdir}/${subdir}/${srcmainfile} ${binsharedfile}" \ + "${binmainfile}" executable [list debug additional_flags=-std=c11]] \ + != "" } { + untested "Couldn't compile test program" + return -1 +} + +set absdir [file dirname [standard_output_file ${binsharedbase}]] + +foreach ld_library_path [list $absdir [relative_filename [pwd] $absdir]] \ + name { absolute relative } { + with_test_prefix $name { + + # Restart, but defer loading until after setting LD_LIBRARY_PATH. + clean_restart + + gdb_test_no_output "set env LD_LIBRARY_PATH=$ld_library_path" \ + "set env LD_LIBRARY_PATH" + + gdb_load ${binmainfile} + + if ![runto_main] { + return + } + + # Print a thread local variable from the shared library to be certain + # that its symbols were loaded from the separate debuginfo file. + gdb_test "print var" \ + "\\\$1 = 42" \ + "print TLS variable from a shared library with separate debug info file" + } +} -- 2.30.2