Building Google glog with CMake on Linux - c++

Question

I want to build Google glog with CMake as part of bigger project (solution, in words of Visual Studio). What I want to have as a result:
cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug
-DCMAKE_INSTALL_PREFIX:PATH=xxx {MAIN CMakeLists.txt location}
cmake --build . --target install --config Debug
will build solution in Debug configuration and install files to xxx folder.
Ok, glog is sub project of main solution:
add_subdirectory(third_party/glog_0.3.4)
On Windows everything is ok (see CMakeLists.txt): everything works as expected.
To build glog on Linux, I need to configure .h.in files too (among other work). CMake configure_file does not works: I have .h files but they contain #undef's only. But glog's ./configure works fine, so I found that ExternalProject_Add() may help:
if(UNIX)
include(ExternalProject)
ExternalProject_Add(glog
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}
CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/configure
CMAKE_GENERATOR 'Unix Makefiles'
BUILD_COMMAND ${MAKE})
endif()
And cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX:PATH=xxx . works fine, but cmake --build . --target install --config Debug will give me:
make: *** No rule to make target 'install'. Stop.
If I invoke cmake --build . --config Debug, then it will build and install glog to /usr/local/lib. Next try:
if(UNIX)
include(ExternalProject)
get_filename_component(glog_absolute_install_dir ${CMAKE_INSTALL_PREFIX} ABSOLUTE)
ExternalProject_Add(glog
SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}
CONFIGURE_COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/configure --prefix=${glog_absolute_install_dir}
CMAKE_GENERATOR 'Unix Makefiles'
BUILD_COMMAND ${MAKE}
INSTALL_DIR ${glog_absolute_install_dir}
INSTALL_COMMAND "${MAKE}")
endif()
will not install files to xxx and just build it to glog-prefix/src/glog-build/.
Ok, I have no idea how to make it work.. And how to
specify install dir
lib build type (static/shared)
configure type (Debug/Release) - not sure that now it works
On Windows, according to glog's documentation, for 2nd case I do next:
add_library(${lib_name} ${lib_type} ${src_files})
if(build_shared_lib)
add_definitions(-DLIBGLOG_EXPORTS)
else()
add_definitions(-DGOOGLE_GLOG_DLL_DECL=)
endif()
Thanks for any help

Answer 1

I will show you by example, the below is my project structure:
The file FindGLog.cmake in the directory cmake is used to find glog, it contents :
# - Try to find Glog
#
# The following variables are optionally searched for defaults
# GLOG_ROOT_DIR: Base directory where all GLOG components are found
#
# The following are set after configuration is done:
# GLOG_FOUND
# GLOG_INCLUDE_DIRS
# GLOG_LIBRARIES
include(FindPackageHandleStandardArgs)
if (NOT DEFINED GLOG_ROOT)
message("set GLOG_ROOT========================")
set (GLOG_ROOT /usr /usr/local /usr/include/)
endif (NOT DEFINED GLOG_ROOT)
#set(GLOG_ROOT_DIR "" CACHE PATH "Folder contains Google glog")
find_path(GLOG_INCLUDE_DIR glog/logging.h
PATHS
${GLOG_ROOT_DIR}
PATH_SUFFIXES
src)
find_library(GLOG_LIBRARY glog libglog
PATHS
${GLOG_ROOT_DIR}
PATH_SUFFIXES
.libs
lib
lib64)
find_package_handle_standard_args(GLOG DEFAULT_MSG
GLOG_INCLUDE_DIR GLOG_LIBRARY)
if(GLOG_FOUND)
set(GLOG_INCLUDE_DIRS ${GLOG_INCLUDE_DIR})
set(GLOG_LIBRARIES ${GLOG_LIBRARY})
message("GLOG_INCLUDE_DIRS ${GLOG_INCLUDE_DIRS}===========")
message("GLOG_LIBRARY ${GLOG_LIBRARY}===========")
endif()
The main CMakeLists.txt use the above FindGLog.cmake to find glog:
cmake_minimum_required(VERSION 3.5)
project(my_caffe)
set(CMAKE_CXX_STANDARD 11)
# find glog
set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
find_package(GLog REQUIRED)
set(SOURCE_FILES main.cpp)
add_executable(my_caffe_test ${SOURCE_FILES})
# link glog
target_link_libraries(my_caffe_test
${GLOG_LIBRARIES}
)
cited from:https://davidstutz.de/running-google-glog-on-travis-ci/

Answer 2

Nowadays (presumably this will be in glog release 0.3.5), there is a CMakeLists.txt included with glog, so no longer any need for ExternalProject.