[BUG] + matser: build fails with gcc 12.0.1

[kloczek]

Describe the bug
Build fails.

System
Which OS, compiler, and compiler version are you using:

• OS: Linux x86/64
• Compiler and version: gcc 12.0.1

[ 25%] Linking CXX shared library libbenchmark.so
cd /home/tkloczko/rpmbuild/BUILD/benchmark-1.6.1/x86_64-redhat-linux-gnu/src && /usr/bin/cmake -E cmake_link_script CMakeFiles/benchmark.dir/link.txt --verbose=1
/usr/bin/g++ -fPIC -O2 -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fdata-sections -ffunction-sections -flto=auto -flto-partition=none  -std=c++11  -Wall  -Wextra  -Wshadow  -pedantic  -pedantic-errors  -fstrict-aliasing  -Wno-deprecated-declarations  -Wstrict-aliasing -DNDEBUG  -Werror  -Wno-deprecated -Wl,-z,relro -Wl,--as-needed -Wl,--gc-sections -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -flto=auto -flto-partition=none -fuse-linker-plugin -Wl,--build-id=sha1 -shared -Wl,-soname,libbenchmark.so.2 -o libbenchmark.so.1.6.1 CMakeFiles/benchmark.dir/benchmark.cc.o CMakeFiles/benchmark.dir/benchmark_api_internal.cc.o CMakeFiles/benchmark.dir/benchmark_name.cc.o CMakeFiles/benchmark.dir/benchmark_register.cc.o CMakeFiles/benchmark.dir/benchmark_runner.cc.o CMakeFiles/benchmark.dir/check.cc.o CMakeFiles/benchmark.dir/colorprint.cc.o CMakeFiles/benchmark.dir/commandlineflags.cc.o CMakeFiles/benchmark.dir/complexity.cc.o CMakeFiles/benchmark.dir/console_reporter.cc.o CMakeFiles/benchmark.dir/counter.cc.o CMakeFiles/benchmark.dir/csv_reporter.cc.o CMakeFiles/benchmark.dir/json_reporter.cc.o CMakeFiles/benchmark.dir/perf_counters.cc.o CMakeFiles/benchmark.dir/reporter.cc.o CMakeFiles/benchmark.dir/sleep.cc.o CMakeFiles/benchmark.dir/statistics.cc.o CMakeFiles/benchmark.dir/string_util.cc.o CMakeFiles/benchmark.dir/sysinfo.cc.o CMakeFiles/benchmark.dir/timers.cc.o  -lrt
In member function 'operator()',
    inlined from '_M_expression_term' at /usr/include/c++/12/bits/regex_compiler.tcc:491:19,
    inlined from '_M_insert_bracket_matcher' at /usr/include/c++/12/bits/regex_compiler.tcc:419:32,
    inlined from '_M_bracket_expression' at /usr/include/c++/12/bits/regex_compiler.tcc:350:7,
    inlined from '_M_atom' at /usr/include/c++/12/bits/regex_compiler.tcc:336:38,
    inlined from '_M_term' at /usr/include/c++/12/bits/regex_compiler.tcc:133:24,
    inlined from '_M_alternative' at /usr/include/c++/12/bits/regex_compiler.tcc:115:24:
/usr/include/c++/12/bits/regex_compiler.tcc:443:32: error: '__last_char._M_char' may be used uninitialized [-Werror=maybe-uninitialized]
  443 |           __matcher._M_add_char(__last_char.get());
      |                                ^
/usr/include/c++/12/bits/regex_compiler.tcc: In member function '_M_alternative':
/usr/include/c++/12/bits/regex_compiler.tcc:413:21: note: '__last_char._M_char' was declared here
  413 |       _BracketState __last_char;
      |                     ^
In member function '_M_add_char',
    inlined from 'operator()' at /usr/include/c++/12/bits/regex_compiler.tcc:443:25,
    inlined from '_M_expression_term' at /usr/include/c++/12/bits/regex_compiler.tcc:491:19,
    inlined from '_M_insert_bracket_matcher' at /usr/include/c++/12/bits/regex_compiler.tcc:419:32,
    inlined from '_M_bracket_expression' at /usr/include/c++/12/bits/regex_compiler.tcc:350:7,
    inlined from '_M_atom' at /usr/include/c++/12/bits/regex_compiler.tcc:336:38,
    inlined from '_M_term' at /usr/include/c++/12/bits/regex_compiler.tcc:133:24,
    inlined from '_M_alternative' at /usr/include/c++/12/bits/regex_compiler.tcc:115:24:
/usr/include/c++/12/bits/regex_compiler.h:450:57: error: '__last_char._M_char' may be used uninitialized [-Werror=maybe-uninitialized]
  450 |         _M_char_set.push_back(_M_translator._M_translate(__c));
      |                                                         ^
/usr/include/c++/12/bits/regex_compiler.tcc: In member function '_M_alternative':
/usr/include/c++/12/bits/regex_compiler.tcc:413:21: note: '__last_char._M_char' was declared here
  413 |       _BracketState __last_char;
      |                     ^
lto1: all warnings being treated as errors

[dmah42]

can you share more about your build setup, maybe your CMake logs too?

[marxin]

Note the -Wmaybe-uninitialized is a warning that has a pretty high false-positive rate.

[marxin]

It's likely fixed with gcc-mirror/gcc@ad66b03, let me test that.

[kloczek]

I've retested with latest gcc 12.0.1 snapshot and I no longer see that issue.
Build is OK however test suite still fails (reported in #1326).
I've retested that against current master (dc901ff).

cmake settings

[tkloczko@devel-g2v x86_64-redhat-linux-gnu]$ cmake -L
CMake Warning:
  No source or binary directory provided.  Both will be assumed to be the
  same as the current working directory, but note that this warning will
  become a fatal error in future CMake releases.


CMake Error: The source directory "/home/tkloczko/rpmbuild/BUILD/benchmark-1.6.1/x86_64-redhat-linux-gnu" does not appear to contain CMakeLists.txt.
Specify --help for usage, or press the help button on the CMake GUI.
-- Cache values
BENCHMARK_BUILD_32_BITS:BOOL=OFF
BENCHMARK_DOWNLOAD_DEPENDENCIES:BOOL=OFF
BENCHMARK_ENABLE_ASSEMBLY_TESTS:BOOL=ON
BENCHMARK_ENABLE_DOXYGEN:BOOL=OFF
BENCHMARK_ENABLE_EXCEPTIONS:BOOL=ON
BENCHMARK_ENABLE_GTEST_TESTS:BOOL=ON
BENCHMARK_ENABLE_INSTALL:BOOL=ON
BENCHMARK_ENABLE_LIBPFM:BOOL=OFF
BENCHMARK_ENABLE_LTO:BOOL=OFF
BENCHMARK_ENABLE_TESTING:BOOL=ON
BENCHMARK_ENABLE_WERROR:BOOL=ON
BENCHMARK_FORCE_WERROR:BOOL=OFF
BENCHMARK_INSTALL_DOCS:BOOL=ON
BENCHMARK_USE_BUNDLED_GTEST:BOOL=OFF
BENCHMARK_USE_LIBCXX:BOOL=OFF
CMAKE_BUILD_TYPE:STRING=RelWithDebInfo
CMAKE_INSTALL_PREFIX:PATH=/usr
GTest_DIR:PATH=/usr/lib64/cmake/GTest
LLVM_FILECHECK_EXE:PATH=/usr/bin/FileCheck

Feel free to close that ticket.

[dmah42]

just to check: i can close this issue as resolved?

[kloczek]

I think yes. Closing.
Thank you 😃