Add CMake support for glog

[prudhomm]

Hi

would it be possible to add cmake support for Glog ? Gflags already support cmake, it would be consistent to have glog supporting it also.
It seems that there have been attempts to do that in the past.

Thanks you very much in advance

[sergiud]

I've added CMake support to glog: https://github.com/sergiud/glog. Tested on Windows using VC 8.0-14.0 CTP 6 and cygwin gcc 4.9.2, and on Arch Linux using gcc 4.9.2 and clang 3.6.

Usage in a CMake project:

cmake_minimum_required (VERSION 2.8.11)
project (myproject)

find_package (glog 0.3.4)

add_executable (myproject myproject.cpp)
target_link_libraries (myproject glog)

[prudhomm]

Hi thanks for your work ! I will test it asap.
how about a pull request on the google/glog to see what the maintainer says ?

[sergiud]

There are minor things left to be done. Once I'm done, I'll create a pull request.

[exxus]

When adding cmake support it would be nice to have also mingw support on windows.
The release 0.3.4 states "attempt to improve mingw-w64 support", but I think that's maybe only for cross compiles.
Building with mingw-w64 seems not to be supported.

[sergiud]

MinGW and CMake support are pretty much unrelated issues. MinGW is simply missing functions that are required to compile glog.

[exxus]

Thank you for your help.

I was able to compile glog with mingw, but I had to use msys to run the configure script, and there were some linker problems with the test. Also there are some problems with pthreads, because glog defines its own pthreads. I had to use mingw without pthread support. But I was able to use the library in my project that I compiled with MinGW and the logging could be used correctly. MinGW does not support symbolic links, but glog can be used without this functionality. I just thought that during the cmake process one could check for mingw compiler and set the correct macros.

Currently I am testing your cmake fork and it also seems that somehow the MSVC Project can not include the gflags headers correctly.

[sergiud]

What MinGW version are you using? Maybe I can take a look.

Would you also post the CMake/compiler output regarding the gflags problem? Thanks.

[exxus]

I am using mingw-w64: i686-4.9.2-win32-sjlj-rt_v3-rev1 from the mingw-w64 project.
Note that in logging.h I had to import stdlib and disable the dllimport stuff also for mingw

#include <stdlib.h>
...
# if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__MINGW32__)
#   define GOOGLE_GLOG_DLL_DECL  __declspec(dllimport)
# else
#   define GOOGLE_GLOG_DLL_DECL
# endif

The problem with gflags is, that the headers are not found.

Fehler  1   error C1083: Datei (Include) kann nicht geöffnet werden: "gflags/gflags.h": No such file or directory  d:\buildlibs\glogcmake\glog\src\base\commandlineflags.h 58  1   glog

From the CmakeCache.txt

//The directory containing a CMake configuration file for Gflags.
Gflags_DIR:PATH=D:/libs/local/cmake

Additionally you could add Cache variable in cmake to disable gflags.

Thank you

[sergiud]

My MinGW installation is missing the strerror_s and localtime_s functions, which are required for the implementation of strerror_r and localtime_r. I pushed a fix for the gflags issue, though.

[sergiud]

As a side note, you have to use the gflags_DIR CMake variable instead of Gflags_DIR now.

[exxus]

Thank you. Compiling without gflags with MSVS works now.
When building with gflags, the gflags headers are still not included automatically.
This is a typo, the gflags include directory is called gflags_INCLUDE_DIR and not gflags_INCLUDE_DIRS.
After fixing this, MSVS complains about:

Compiler Error C2370
'identifier' : redefinition; different storage class

in logging.cc line 105, 107, 134, 1034, 175, 140, 142, 172, 138, 128, 166, 168
e.g.: 'fLB::FLAGS_alsologtostderr'
in vlog_is_on line 53
'fLI::FLAGS_v'

and

Compiler Error C2872
'symbol' : ambiguous symbol

'int64' and 'uint32' in several lines in logging_unittest.cc

mingw with posix threads is not compiling, I will try mingw with win32 threads later.

[sergiud]

Thanks for letting me know. The gflags issues should be fixed now.

[exxus]

using mingw with win32 threads:

PS D:\buildlibs\glogcmake\glog\build> mingw32-make
Scanning dependencies of target glog
[  8%] Building CXX object CMakeFiles/glog.dir/src/demangle.cc.obj
[ 16%] Building CXX object CMakeFiles/glog.dir/src/logging.cc.obj
[ 25%] Building CXX object CMakeFiles/glog.dir/src/raw_logging.cc.obj
[ 33%] Building CXX object CMakeFiles/glog.dir/src/symbolize.cc.obj
[ 41%] Building CXX object CMakeFiles/glog.dir/src/utilities.cc.obj
[ 50%] Building CXX object CMakeFiles/glog.dir/src/vlog_is_on.cc.obj
[ 58%] Building CXX object CMakeFiles/glog.dir/src/signalhandler.cc.obj
[ 66%] Building CXX object CMakeFiles/glog.dir/src/windows/port.cc.obj
D:\buildlibs\glogcmake\glog\src\windows\port.cc: In function 'int snprintf(char*, size_t, const char*, ...)':
D:\buildlibs\glogcmake\glog\src\windows\port.cc:59:5: error: redefinition of 'int snprintf(char*, size_t, const char*, .
..)'
 int snprintf(char *str, size_t size, const char *format, ...) {
     ^
In file included from D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/locale.h:1
2:0,
                 from D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/clocal
e:42,
                 from D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/i686-w
64-mingw32/bits/c++locale.h:41,
                 from D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/bits/l
ocalefwd.h:40,
                 from D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/string
:43,
                 from D:\buildlibs\glogcmake\glog\src\windows\port.cc:43:
D:/Software/mingw-w64/i686-4.9.2-win32-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/stdio.h:339:5: note: 'int snprin
tf(char*, size_t, const char*, ...)' previously defined here
 int snprintf (char *__stream, size_t __n, const char *__format, ...)
     ^
At global scope:
cc1plus.exe: warning: unrecognized command line option "-Wno-unnamed-type-template-args"
CMakeFiles\glog.dir\build.make:222: recipe for target 'CMakeFiles/glog.dir/src/windows/port.cc.obj' failed
mingw32-make[2]: *** [CMakeFiles/glog.dir/src/windows/port.cc.obj] Error 1
CMakeFiles\Makefile2:94: recipe for target 'CMakeFiles/glog.dir/all' failed
mingw32-make[1]: *** [CMakeFiles/glog.dir/all] Error 2
makefile:146: recipe for target 'all' failed
mingw32-make: *** [all] Error 2
PS D:\buildlibs\glogcmake\glog\build>

using mingw with posix threads:

PS D:\buildlibs\glogcmake\glog\build> mingw32-make
Scanning dependencies of target glog
[  8%] Building CXX object CMakeFiles/glog.dir/src/demangle.cc.obj
[ 16%] Building CXX object CMakeFiles/glog.dir/src/logging.cc.obj
In file included from D:\buildlibs\glogcmake\glog\src\utilities.h:78:0,
                 from D:\buildlibs\glogcmake\glog\src\logging.cc:32:
D:/buildlibs/glogcmake/glog/src/windows/port.h:139:15: error: conflicting declaration 'typedef DWORD pthread_t'
 typedef DWORD pthread_t;
               ^
In file included from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/i686-w
64-mingw32/bits/gthr-default.h:35:0,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/i686-w
64-mingw32/bits/gthr.h:148,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/ext/at
omicity.h:35,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/bits/b
asic_string.h:39,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/string
:52,
                 from D:\buildlibs\glogcmake\glog\src\utilities.h:75,
                 from D:\buildlibs\glogcmake\glog\src\logging.cc:32:
D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/pthread.h:196:19: note: previous
 declaration as 'typedef uintptr_t pthread_t'
 typedef uintptr_t pthread_t;
                   ^
In file included from D:\buildlibs\glogcmake\glog\src\utilities.h:78:0,
                 from D:\buildlibs\glogcmake\glog\src\logging.cc:32:
D:/buildlibs/glogcmake/glog/src/windows/port.h:140:15: error: conflicting declaration 'typedef DWORD pthread_key_t'
 typedef DWORD pthread_key_t;
               ^
In file included from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/i686-w
64-mingw32/bits/gthr-default.h:35:0,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/i686-w
64-mingw32/bits/gthr.h:148,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/ext/at
omicity.h:35,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/bits/b
asic_string.h:39,
                 from D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/c++/string
:52,
                 from D:\buildlibs\glogcmake\glog\src\utilities.h:75,
                 from D:\buildlibs\glogcmake\glog\src\logging.cc:32:
D:/Software/mingw-w64/i686-4.9.2-posix-sjlj-rt_v3-rev1/mingw32/i686-w64-mingw32/include/pthread.h:182:18: note: previous
 declaration as 'typedef unsigned int pthread_key_t'
 typedef unsigned pthread_key_t;
                  ^
D:/buildlibs/glogcmake/glog/src/windows/port.h:142:8: error: expected identifier before numeric constant
 enum { PTHREAD_ONCE_INIT = 0 };   // important that this be 0! for SpinLock
        ^
D:/buildlibs/glogcmake/glog/src/windows/port.h:142:8: error: expected '}' before numeric constant
D:/buildlibs/glogcmake/glog/src/windows/port.h:142:8: error: expected unqualified-id before numeric constant
In file included from D:\buildlibs\glogcmake\glog\src\utilities.h:78:0,
                 from D:\buildlibs\glogcmake\glog\src\logging.cc:32:
D:/buildlibs/glogcmake/glog/src/windows/port.h:142:30: error: expected declaration before '}' token
 enum { PTHREAD_ONCE_INIT = 0 };   // important that this be 0! for SpinLock
                              ^
cc1plus.exe: warning: unrecognized command line option "-Wno-unnamed-type-template-args"
CMakeFiles\glog.dir\build.make:78: recipe for target 'CMakeFiles/glog.dir/src/logging.cc.obj' failed
mingw32-make[2]: *** [CMakeFiles/glog.dir/src/logging.cc.obj] Error 1
CMakeFiles\Makefile2:94: recipe for target 'CMakeFiles/glog.dir/all' failed
mingw32-make[1]: *** [CMakeFiles/glog.dir/all] Error 2
makefile:146: recipe for target 'all' failed
mingw32-make: *** [all] Error 2

[sergiud]

I see. Adding MinGW support basically requires some code refactoring, which I can't really help with.