Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Clang: Suppress warnings if built with Clang (gdb) #54

Closed
wants to merge 1 commit into from

Conversation

a4lg
Copy link
Owner

@a4lg a4lg commented Sep 13, 2022

@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch 15 times, most recently from 2e1ed8f to 2ae1804 Compare September 18, 2022 09:55
@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch 15 times, most recently from 740b57f to fca0a16 Compare September 22, 2022 11:35
@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch 12 times, most recently from 24e03d5 to a16db39 Compare November 2, 2022 01:45
@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch 9 times, most recently from b92664d to f5ebe78 Compare November 10, 2022 06:56
@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch 3 times, most recently from 59c2393 to 7276902 Compare November 13, 2022 04:56
Gnulib generates a warning if the system version of certain functions
are used (to redirect the developer to use Gnulib version).  It caused a
compiler error when...

-   Compiled with Clang
-   -Werror is specified (by default)
-   C++ standard used by Clang is before C++17 (by default as of 15.0.0)
    when this unit test is activated.

This issue is raised as PR28413.

However, previous proposal to fix this issue (a "fix" to Gnulib):
<https://lists.gnu.org/archive/html/bug-gnulib/2021-10/msg00003.html>
was rejected because it ruins the intent of Gnulib warnings.

So, we need a Binutils/GDB-side solution.

This commit tries to address this issue on the GDB side.  We have
"include/diagnostics.h" to disable certain warnings only when necessary.

This commit suppresses the Gnulib warnings by surrounding entire #include
block with DIAGNOSTIC_IGNORE_USER_DEFINED_WARNINGS to disable Gnulib-
generated warnings on all standard C++ header files.
@a4lg a4lg force-pushed the clang-nowarn-gdb-generic-failures branch from 7276902 to 1d9323b Compare November 13, 2022 06:12
@a4lg
Copy link
Owner Author

a4lg commented Nov 15, 2022

Upstreamed as a5b6e43 (with additional comment).

@a4lg a4lg closed this Nov 15, 2022
@a4lg a4lg deleted the clang-nowarn-gdb-generic-failures branch November 15, 2022 03:55
a4lg pushed a commit that referenced this pull request Aug 6, 2023
…s_debug_type}

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp
and target board debug-types, I run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=9654)
  Write of size 1 at 0x7b200000420d by main thread:
    #0 dwarf2_per_cu_data::get_header() const gdb/dwarf2/read.c:21513 (gdb+0x8d1eee)
    #1 dwarf2_per_cu_data::addr_size() const gdb/dwarf2/read.c:21524 (gdb+0x8d1f4e)
    #2 dwarf2_cu::addr_type() const gdb/dwarf2/cu.c:112 (gdb+0x806327)
    #3 set_die_type gdb/dwarf2/read.c:21932 (gdb+0x8d3870)
    #4 read_base_type gdb/dwarf2/read.c:15448 (gdb+0x8bcacb)
    #5 read_type_die_1 gdb/dwarf2/read.c:19832 (gdb+0x8cc0a5)
    #6 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
    #7 lookup_die_type gdb/dwarf2/read.c:19739 (gdb+0x8cbdc7)
    #8 die_type gdb/dwarf2/read.c:19593 (gdb+0x8cb68a)
    #9 read_subroutine_type gdb/dwarf2/read.c:14648 (gdb+0x8b998e)
    #10 read_type_die_1 gdb/dwarf2/read.c:19792 (gdb+0x8cbf2f)
    #11 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
    #12 read_func_scope gdb/dwarf2/read.c:10154 (gdb+0x8a4f36)
    #13 process_die gdb/dwarf2/read.c:6667 (gdb+0x898daa)
    #14 read_file_scope gdb/dwarf2/read.c:7682 (gdb+0x89bad8)
    #15 process_die gdb/dwarf2/read.c:6654 (gdb+0x898ced)
    #16 process_full_comp_unit gdb/dwarf2/read.c:6418 (gdb+0x8981de)
    #17 process_queue gdb/dwarf2/read.c:5690 (gdb+0x894433)
    #18 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1770 (gdb+0x88623a)
    #19 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x886300)
    #20 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88b1f1)
    #21 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16917 (gdb+0x8c228e)
    #22 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf39055)
    #23 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66ab7)
    #24 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf6711b)
    #25 operator() gdb/symtab.c:2562 (gdb+0xf67272)
    #26 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf776b1)
    #27 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77708)
    #28 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3fc97)
    #29 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xecae47)
    #30 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
    #31 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf674fb)
    #32 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf67780)
    #33 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf66d6e)
    #34 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf65cb3)
    #35 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf64dab)
    #36 set_initial_language() gdb/symfile.c:1708 (gdb+0xf43074)
    #37 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf41608)
    #38 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf42faf)
    #39 file_command gdb/exec.c:554 (gdb+0x94ff29)
    #40 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
    #41 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
    #42 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff379c)
    #43 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94b5bc)
    #44 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94bc79)
    #45 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x1034efc)
    #46 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94ab61)
    #47 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11be4ef)
    #48 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a960)
    #49 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94aa21)
    #50 stdin_event_handler gdb/ui.c:155 (gdb+0x10751a0)
    #51 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d95bac)
    #52 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d962e4)
    #53 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d946d0)
    #54 start_event_loop gdb/main.c:412 (gdb+0xb5ab52)
    #55 captured_command_loop gdb/main.c:476 (gdb+0xb5ad41)
    #56 captured_main gdb/main.c:1320 (gdb+0xb5cec1)
    #57 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5cf70)
    #58 main gdb/gdb.c:32 (gdb+0x416776)

  Previous read of size 1 at 0x7b200000420d by thread T11:
    #0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x831630)
    #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x832897)
    #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x82db8d)
    #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:645 (gdb+0x7f1d49)
    #4 operator() gdb/dwarf2/cooked-index.c:474 (gdb+0x7f0f31)
    #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2a13)
    #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
    #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
    #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
    #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
    #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
    #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
    #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
    #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
    #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
    #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
    #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
    #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
    #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
    #19 pthread_once <null> (libtsan.so.0+0x4457c)
    #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
    #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
    #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
    #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
    #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dad25a)
    #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dacb7c)
    #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dadc2b)
    #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dad05c)
    #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1db038e)
    #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1db0319)
    #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1db02ce)
    #31 <null> <null> (libstdc++.so.6+0xdcac2)
  ...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:21513 in dwarf2_per_cu_data::get_header() const
...

The race happens when issuing the "file $exec" command.

The race is between:
- a worker thread writing the index cache, and in the process reading
   dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::m_header_read_in.

The two bitfields dwarf2_per_cu_data::m_header_read_in and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.

Fix this by making dwarf2_per_cu_data::m_header_read_in a packed<bool, 1>.

Tested on x86_64-linux.

Approved-By: Tom Tromey <[email protected]>

PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
bug Something isn't working
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant