cmake-03-CompilerOption

LANGUAGES C CXX

	cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
	
	# project name and language, load c and cxx compiler
	project(recipe-06 LANGUAGES C CXX)
	
	message(STATUS "Is the C++ compiler loaded? ${CMAKE_CXX_COMPILER_LOADED}")
	if(CMAKE_CXX_COMPILER_LOADED)
	  message(STATUS "The C++ compiler ID is: ${CMAKE_CXX_COMPILER_ID}")
	  message(STATUS "Is the C++ from GNU? ${CMAKE_COMPILER_IS_GNUCXX}")
	  message(STATUS "The C++ compiler version is: ${CMAKE_CXX_COMPILER_VERSION}")
	endif()
	
	message(STATUS "Is the C compiler loaded? ${CMAKE_C_COMPILER_LOADED}")
	if(CMAKE_C_COMPILER_LOADED)
	  message(STATUS "The C compiler ID is: ${CMAKE_C_COMPILER_ID}")
	  message(STATUS "Is the C from GNU? ${CMAKE_COMPILER_IS_GNUCC}")
	  message(STATUS "The C compiler version is: ${CMAKE_C_COMPILER_VERSION}")
	endif()
	
	$ cmake .
	-- The C compiler identification is GNU 9.3.0
	-- The CXX compiler identification is GNU 9.3.0
	-- Check for working C compiler: /usr/bin/cc
	-- Check for working C compiler: /usr/bin/cc -- works
	-- Detecting C compiler ABI info
	-- Detecting C compiler ABI info - done
	-- Detecting C compile features
	-- Detecting C compile features - done
	-- Check for working CXX compiler: /usr/bin/c++
	-- Check for working CXX compiler: /usr/bin/c++ -- works
	-- Detecting CXX compiler ABI info
	-- Detecting CXX compiler ABI info - done
	-- Detecting CXX compile features
	-- Detecting CXX compile features - done
	-- Is the C++ compiler loaded? 1
	-- The C++ compiler ID is: GNU
	-- Is the C++ from GNU? 1
	-- The C++ compiler version is: 9.3.0
	-- Is the C compiler loaded? 1
	-- The C compiler ID is: GNU
	-- Is the C from GNU? 1
	-- The C compiler version is: 9.3.0
	-- Configuring done
	-- Generating done
	-- Build files have been written to: /home/jianleya/trainning/cmake/cmake

CMAKE_CXX_FLAGS

cmake_minimum_required(VERSION 3.5)

# Set a default C++ compile flag
set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DEX2" CACHE STRING "Set C++ Compiler Flags" FORCE)
project (compile_flags)

add_executable(cmake_examples_compile_flags main.cpp)

can also use cmake options
$ cmake … -DCMAKE_CXX_FLAGS="-DEX2"

CMAKE_BUILD_TYPE

	# build type specfies build options
	cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
	project(recipe-07 LANGUAGES C CXX)
	
	# we default to Release build type
	if(NOT CMAKE_BUILD_TYPE)
	  set(CMAKE_BUILD_TYPE Release CACHE STRING "Build type" FORCE)
	endif()
	
	message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")
	
	message(STATUS "C flags, Debug configuration: ${CMAKE_C_FLAGS_DEBUG}")
	message(STATUS "C flags, Release configuration: ${CMAKE_C_FLAGS_RELEASE}")
	message(STATUS "C flags, Release configuration with Debug info: ${CMAKE_C_FLAGS_RELWITHDEBINFO}")
	message(STATUS "C flags, minimal Release configuration: ${CMAKE_C_FLAGS_MINSIZEREL}")
	
	message(STATUS "C++ flags, Debug configuration: ${CMAKE_CXX_FLAGS_DEBUG}")
	message(STATUS "C++ flags, Release configuration: ${CMAKE_CXX_FLAGS_RELEASE}")
	message(STATUS "C++ flags, Release configuration with Debug info: ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
	message(STATUS "C++ flags, minimal Release configuration: ${CMAKE_CXX_FLAGS_MINSIZEREL}")

CMAKE_CXX_FLAGS

similar as
CMAKE_CXX_FLAGS

target_compile_options(flags)

	cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
	project(recipe-08 LANGUAGES CXX)
	message("C++ compiler flags: ${CMAKE_CXX_FLAGS}")
	
	list(APPEND flags "-fPIC" "-Wall")
	if(NOT WIN32)
	  list(APPEND flags "-Wextra" "-Wpedantic")
	endif()
	
	add_library(geometry
	  STATIC
	    geometry_circle.cpp
	    geometry_circle.hpp
	    geometry_polygon.cpp
	    geometry_polygon.hpp
	    geometry_rhombus.cpp
	    geometry_rhombus.hpp
	    geometry_square.cpp
	    geometry_square.hpp
	  )
	
	target_compile_options(geometry
	  PRIVATE
	    ${flags}
	  )
	
	add_executable(compute-areas compute-areas.cpp)
	
	target_compile_options(compute-areas
	  PRIVATE
	    "-fPIC"
	  )
	
	target_link_libraries(compute-areas geometry)
	
	

set_target_properties (c++14)

	# set as c++14  etc
	
	cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
	project(recipe-09 LANGUAGES CXX)

	set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
	
	add_library(animals
	  SHARED
	    Animal.cpp
	    Animal.hpp
	    Cat.cpp
	    Cat.hpp
	    Dog.cpp
	    Dog.hpp
	    Factory.hpp
	  )
	
	set_target_properties(animals
	  PROPERTIES
	    CXX_STANDARD 14
	    CXX_EXTENSIONS OFF
	    CXX_STANDARD_REQUIRED ON
	    POSITION_INDEPENDENT_CODE 1
	  )
	
	add_executable(animal-farm animal-farm.cpp)
	
	set_target_properties(animal-farm
	  PROPERTIES
	    CXX_STANDARD 14
	    CXX_EXTENSIONS OFF
	    CXX_STANDARD_REQUIRED ON
	  )
	
	target_link_libraries(animal-farm animals)
	

target_compile_definitions (-D)

cmake_minimum_required(VERSION 3.5)

# Set the project name
project (compile_flags)

# Add an executable
add_executable(cmake_examples_compile_flags main.cpp)
#equals to "gcc/g++ -D EX3" when build target cmake_examples_compile_flags
target_compile_definitions(cmake_examples_compile_flags
    PRIVATE EX3
)