How to use header only way

[chengm349]

I did not use -DSPDLOG_COMPILED_LIB, but include spdlog header files path.

I got these link error:

/fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/format.h:877: undefined reference to fmt::v6::internal::assert_fail(char const*, int, char const*)' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function char* fmt::v6::internal::format_decimal<unsigned int, char, char* fmt::v6::internal::format_decimal<char, char*, unsigned int>(char*, unsigned int, int)::{lambda(char*)#1}>(char* fmt::v6::internal::format_decimal<char, char*, unsigned int>(char*, unsigned int, int)::{lambda(char*)#1}, unsigned int, int, char* fmt::v6::internal::format_decimal<char, char*, unsigned int>(char*, unsigned int, int)::{lambda(char*)#1})':
/fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/format.h:843: undefined reference to fmt::v6::internal::assert_fail(char const*, int, char const*)' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function endl(FtSpdlogDebugStream&)':
/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:60: undefined reference to spdlog::default_logger()' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function endl(FtSpdlogTraceStream&)':
/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:40: undefined reference to spdlog::default_logger()' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function endl(FtSpdlogCriticalStream&)':
/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:142: undefined reference to spdlog::default_logger()' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function endl(FtSpdlogErrorStream&)':
/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:122: undefined reference to spdlog::default_logger()' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function endl(FtSpdlogWarnStream&)':
/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:101: undefined reference to spdlog::default_logger()' /fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o):/fs02/home/thirdparty/spdlog2/include/FtSpdlogStream.h:81: more undefined references to spdlog::default_logger()' follow
/fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function fmt::v6::basic_format_context<std::back_insert_iterator<fmt::v6::internal::buffer<char> >, char>::on_error(char const*)': /fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/core.h:1169: undefined reference to fmt::v6::internal::error_handler::on_error(char const*)'
/fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function unsigned long long fmt::v6::internal::width_checker<fmt::v6::internal::error_handler>::operator()<float, 0>(float)': /fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/format.h:1988: undefined reference to fmt::v6::internal::error_handler::on_error(char const*)'
/fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function unsigned long long fmt::v6::internal::precision_checker<fmt::v6::internal::error_handler>::operator()<float, 0>(float)': /fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/format.h:2008: undefined reference to fmt::v6::internal::error_handler::on_error(char const*)'
/fs02/home/jenkins/workspace/Rel-15-1-0_PROD/Rel-15-1-54_c++14/directfeeds/face/AS7/libface.a(FtSpdFileLog.o): In function std::make_unsigned<int>::type fmt::v6::internal::to_unsigned<int>(int)': /fs02/home/thirdparty/spdlog2/include/spdlog/fmt/bundled/core.h:266: undefined reference to fmt::v6::internal::assert_fail(char const*, int, char const*)'
collect2: error: ld returned 1 exit status

my program coredumps when use SPDLOG_COMPILED_LIB. I want to try header files only.

[tt4g]

If you are using spdlog with more than one library, make sure the version and build options match exactly.

In addition, if you link the static library in the wrong order, a link error will occur.

• linker - Why does the order in which libraries are linked sometimes cause errors in GCC? - Stack Overflow
• Library order in static linking - Eli Bendersky's website

[chengm349]

this time, I just want to try header files only. why still error in linking stage? or I should still link some sub-libs although no need of whole libspdlog.a?

[tt4g]

For link errors, libface.a appears in the message.
Looking at the Makefile in this comment #1509 (comment), libface.a looked like a library, not an application.

Therefore, I determined that you linked multiple static libraries to your application and the build failed. Is this wrong?

[chengm349]

thank you very much. you are right that I also linked the static lib for libface.a in its makefile. Now it's ok and no coredump. Same whole project code that if i use static lib, it will crash. very strange. Just that the header file only almost double my exe size compared with static way.

[chengm349]

and I am very sure my project only links spdlog static lib once because of this HEADER file only check.

[chengm349]

in fact, initially I used header file only way and my code ran ok. Later I downloaded new version of spdlog and tried static way, then immediately crashed as reported. Now I use our old logging method and my code is running ok. I have some time now so trying to see how can I use spdlog's static method.

[chengm349]

it seems that signal function is happy with header file only mood.

[tt4g]

As noted above (#1511 (comment)), spdlog is not guaranteed to work with signal functions. This is a move based on the C++ standard.

[chengm349]

understood. I just feedback the difference btw header-only and static lib modes.