CMake - useful tips

What you may need in your simple project and cannot find in tutorials (especially issues about per configuration settings -
for other usages than examples here please refer to https://cmake.org/cmake/help/v3.0/policy/CMP0043.html) 

• get absolute path

get_filename_component(ALPHAROOT "../../../../../../../../../../../../.." ABSOLUTE CACHE)

• black font 

message(STATUS "what I wanted to say")

• set OutputDirectory

set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY D:/lib)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY D:/lib)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY D:/bin)

• some cache variables are set at the time of command "project(ProjectName)", co if you can cache these variables but set default value for them

set them before command "project(ProjectName)"

• decide according to platform you are generating for

if( WIN32 )
if( MSVC )
if( CMAKE_COMPILER_IS_GNUCXX )
if( UNIX )

• set custon set of configurations 

#(write before "project(ProjectName)" command)
set(CMAKE_CONFIGURATION_TYPES Debug Release ClientConfig DebugFileCamera ReleaseFileCamera  CACHE TYPE INTERNAL FORCE)

• specify configurations which should be taken as debug (i.e. which should link with debug libs)

set_property(GLOBAL PROPERTY 
DEBUG_CONFIGURATIONS 
"Debug;DebugFileCamera")

• compiler flags per configuration (i.e. configration with name ClientConfig)

set(CMAKE_CXX_FLAGS_CLIENTCONFIG "${CMAKE_CXX_FLAGS_RELEASE} /W1")

• linker flags per configuration (i.e. configration with name ClientConfig) & how to avoid error with /SUBSYSTEM:WINDOWS

set(CMAKE_EXE_LINKER_FLAGS_CLIENTCONFIG "${CMAKE_EXE_LINKER_FLAGS_RELEASE} /SUBSYSTEM:WINDOWS /ENTRY:mainCRTStartup"
)

• postfix per configuration

set(CMAKE_CLIENTCONFIG_POSTFIX "_ClientConfig" CACHE STRING "x")
#but it does not work for executables
#you must do it per target
set_target_properties( MySubprojct
    PROPERTIES
    DEBUG_POSTFIX ${CMAKE_DEBUG_POSTFIX}
    RELEASE_POSTFIX ${CMAKE_RELEASE_POSTFIX}
    CLIENTCONFIG_POSTFIX ${CMAKE_CLIENTCONFIG_POSTFIX}
    DEBUGFILECAMERA_POSTFIX ${CMAKE_DEBUGFILECAMERA_POSTFIX}
    RELEASEFILECAMERA_POSTFIX ${CMAKE_ RELEASEFILECAMERA_POSTFIX}
)

• set compile definition

set_property(DIRECTORY APPEND PROPERTY

 COMPILE_DEFINITIONS _WIN32_WINNT=0x0501

)

• set compile definition per configuration

set_property(DIRECTORY APPEND PROPERTY
  COMPILE_DEFINITIONS $<$<CONFIG:ClientConfig>:CLIENT_CONFIG>
  )

• embed OpenCV

#use first line if you want to use dynamically linked OpenCV

set(OpenCV_STATIC OFF)

FIND_PACKAGE(OpenCV REQUIRED)

#OpenCV does not distinguish between debug and release configurations

# as we have labeled it, we must set it separately(i.e.)

set_target_properties(${OpenCV_LIBS} PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

• embed Boost

FIND_PACKAGE(Boost REQUIRED COMPONENTS 

  system

  filesystem

  thread

  date_time

  iostreams

  serialization

  chrono

  atomic

  regex

  log

)

• embed VTK

FIND_PACKAGE(VTK REQUIRED)

include(${VTK_USE_FILE})

# again VTK does not distinguish between debug and release configurations 

#as we have labeled it, we must set it separately(i.e.)

set_target_properties(${VTK_LIBRARIES} PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

#another problem is with VTK, after use copy paste this

macro(REMOVE_VTK_DEFINITIONS)

   get_directory_property(_dir_defs DIRECTORY ${CMAKE_SOURCE_DIR} COMPILE_DEFINITIONS)

   set(_vtk_definitions)

   foreach(_item ${_dir_defs})

       if(_item MATCHES "vtk*")

           list(APPEND _vtk_definitions -D${_item})

       endif()

   endforeach()

   remove_definitions(${_vtk_definitions})

endmacro(REMOVE_VTK_DEFINITIONS)

REMOVE_VTK_DEFINITIONS()

• embed Qt

find_package(Qt5Gui)

find_package(Qt5Core)

find_package(Qt5Widgets)

if (${Qt5Gui_FOUND} AND ${Qt5Core_FOUND} AND ${Qt5Widgets_FOUND})

message(STATUS "Qt5 found")

set(CMAKE_AUTOMOC ON)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

#Qt also does not distinguish between debug and release configurations 

#as we have labeled it, we must set it separately(i.e.)

set_target_properties(Qt5::Core PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

set_target_properties(Qt5::Core PROPERTIES MAP_IMPORTED_CONFIG_RELEASEFILECAMERA "RELEASE")

set_target_properties(Qt5::Core PROPERTIES MAP_IMPORTED_CONFIG_CLIENTCONFIG "RELEASE")

set_target_properties(Qt5::Widgets PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

set_target_properties(Qt5::Widgets PROPERTIES MAP_IMPORTED_CONFIG_RELEASEFILECAMERA "RELEASE")

set_target_properties(Qt5::Widgets PROPERTIES MAP_IMPORTED_CONFIG_CLIENTCONFIG "RELEASE")

set_target_properties(Qt5::Gui PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

set_target_properties(Qt5::Gui PROPERTIES MAP_IMPORTED_CONFIG_RELEASEFILECAMERA "RELEASE")

set_target_properties(Qt5::Gui PROPERTIES MAP_IMPORTED_CONFIG_CLIENTCONFIG "RELEASE")

set_target_properties(Qt5::WinMain PROPERTIES MAP_IMPORTED_CONFIG_DEBUGFILECAMERA "DEBUG")

set_target_properties(Qt5::WinMain PROPERTIES MAP_IMPORTED_CONFIG_RELEASEFILECAMERA "RELEASE")

set_target_properties(Qt5::WinMain PROPERTIES MAP_IMPORTED_CONFIG_CLIENTCONFIG "RELEASE")

else()

message("Qt5 not found")

endif()