Read cmake in one article

This article is based on VS Angle description CMake The grammatical . Specific grammatical correspondence , Refer to the following table .

CMake Function corresponds to VS Related settings

VS Related settings	CMake function
Specify the directory containing header files	target_include_directories
Specify the link library Directory	target_link_directories
Specify the link library	target_link_libraries
Appoint C++ standard	set(CMAKE_CXX_STANDARD 11)
Specify compiler version	cmake -G “Visual Studio 12 2013”
Specify platform set	cmake -G “Visual Studio 12 2013 Win64”
Specify the compilation type	set(CMAKE_BUILD_TYPE “Debug”） Equivalent to g++ -g
Specify precompiled macros	add_definitions(-Dxxx -Dyyy ) must -D start
Specify the solution name	project(xxxx)

CMake common Built-in variables

CMake Built-in variables	explain （ All paths are full paths ）
PROJECT_NAME	CMakeList.txt In the setting of project_name
PROJECT_SOURCE_DIR	root CMakeLists.txt Path
PROJECT_BINARY_DIR	Construction directory of the project （build Catalog ）
CMAKE_CURRENT_SOURCE_DIR	At present ’CMakeLists.txt’ Path
CMAKE_CURRENT_BINARY_DIR	Currently in process ’ Build directory ’
CMAKE_CURRENT_LIST_DIR	What is being processed ’cmake file ’ directory
CMAKE_CURRENT_LIST_FILE	What is being processed ’CMakeLists.txt or cmake’ The full path of the file
CMAKE_CURRENT_LIST_LINE	What is being processed ’CMakeLists.txt or cmake’ Of documents ’ Line number ’
CMAKE_PROJECT_NAME	Whole project ’ Configured project_name
LIBRARY_OUTPUT_DIR	The directory where the library is stored （ User settings are required ）
BINARY_OUTPUT_DIR	The storage directory of executable files （ User settings are required ）

CMake Hellow word

project
project/main.cpp
project/CMakeLists.txt

project/build

project/CMakeLists.txt

# Set up CMake Version for 
cmake_minimum_required(VERSION 3.10)

# Set project name 
project(hellow)

# Set up C++11 standard 
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED true)

# Add executable 
add_executable(hellow main.cpp)

perform CMake Instructions

# Current directory build

#-G Specify compiler Vs2013 And platform toolset types X64
cmake -G "Visual Studio 12 2013 Win64" ../

Appoint Debug Pattern （-g）

set(CMAKE_BUILD_TYPE "Debug")

Generate mymath library add_library

project/mymath
project/mymath/mymath.h
project/mymath/mymath.cpp
project/mymath/CMakeLists.txt

project/CMakeLists.txt

# Add a subdirectory to the compilation project , Subdirectories should contain CMakeLists.txt
add_subdirectory(mymath)

# Add header file containing directory 
target_include_directories(hellow PUBLIC 
                        "${PROJECT_SOURCE_DIR}/mymath"
                        )

# link lib
target_link_libraries(hellow PUBLIC mymath)

project/mymath/CMakeLists.txt

# add to lib The default is static library , If specified SHARED Dynamic library 
add_library(mymath SHARED mymath.cpp)

This will generate mymath The library , The following is complete project/CMakeLists.txt

# Set up CMake Version for 
cmake_minimum_required(VERSION 3.10)

# Set project name 
project(hellow)

# Set up C++11 standard 
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED true)

# Add a subdirectory to the compilation project , Subdirectories should contain CMakeLists.txt
add_subdirectory(mymath)

# Add executable 
add_executable(hellow main.cpp)

# Add header file containing directory 
target_include_directories(hellow PUBLIC 
                        "${PROJECT_SOURCE_DIR}/mymath"
                        )
# link lib
target_link_libraries(hellow PUBLIC mymath)

Link third party libraries

Link below d://test//test.lib For example ,test.lib The header file of is in d://test//include//

# additional test.lib
target_link_libraries(hellow PUBLIC mymath test)
# Appoint lib Warehouse location 
target_link_directories(hellow PUBLIC "d:/test")
# Appoint lib Header file location 
target_include_directories(hellow PUBLIC 
                        "d:/test/include"
                        "${PROJECT_SOURCE_DIR}/mymath"
                        )

The following is complete project/CMakeLists.txt

# Set up CMake Version for 
cmake_minimum_required(VERSION 3.10)

# Set project name 
project(hellow)

# Set up C++11 standard 
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED true)

# Add a subdirectory to the compilation project , Subdirectories should contain CMakeLists.txt
add_subdirectory(mymath)

# Add executable 
add_executable(hellow main.cpp)

# Add header file containing directory 
target_include_directories(hellow PUBLIC 
						"d:/test/include"
                        "${PROJECT_SOURCE_DIR}/mymath"
                        )
# link lib
target_link_libraries(hellow PUBLIC mymath test)


# Specify the directory of the link library 
target_link_directories(hellow PUBLIC "d:/test")

Add predefined macros add_definitions

for example ： Must define USE_OPEN_SSL Ability to open openssl

# Add predefined macros , must -D start 
add_definitions(-DUSE_OPEN_SLL)

Multi document inclusion processing

If the target contains multiple files , If you specify it manually, it will be troublesome . Can pass aux_source_directory Scan and get the current directory file .

# increase sub function 
project/sub.cpp
project/sub.h

# Scan the current directory file , And saved in variable all_file in 
aux_source_directory("${CMAKE_CURRENT_SOURCE_DIR}" all_file)
add_executable(hellow ${
    all_file})

Configure the project version number and information

# Set the project name and version 
project(Tutorial VERSION 1.0)

# Configure the header file to pass the version number to the source code 
# Configure macro definition , The default value of configuration is ON, If you want to close  cmake -DUSE_MYMATH=OFF
#option  except ON Everything else defaults to OFF
option(USE_MYMATH "user mymath.lib" ON)

# Pass a string to the configuration file 
set(var_Key "hellow word")
# Pass on INT Give the configuration file 
set(INT_Key 1)

# Input file   The output file 
configure_file(hellow_ver.h.in hellow_ver.h)

# Due to the configured file hellow_ver.h Will be written to the binary directory 
# So we have to add this directory to  include  File search path 
target_include_directories(hellow PUBLIC 
						"d:/test/include"
                        "${PROJECT_SOURCE_DIR}/mymath"
                        "${PROJECT_BINARY_DIR}"
                        )

hellow_ver.h.in

// Configured project version number 
#define hellow_VERSION_MAJOR @[email protected]
#define hellow_VERSION_MINOR @[email protected]

// Macro definition 
#cmakedefine USE_MYMATH
// Be careful ：${} The name between should be the same as cmakedefine The following variable names are the same 
// Variable name and cmakeLists.txt Set the same variable name 
#cmakedefine var_Key "@[email protected]”
#cmakedefine INT_Key @[email protected]

Generated after running hellow_ver.h

If you want to cancel USE_MYMATH have access to -DUSE_MYMATH=OFF

cmake -G "Visual Studio 12 2013 Win64" ../ -DUSE_MYMATH=OFF

Generate dynamic library or Static library

# determine mymath.lib Whether to use static library 
option(MYMATH_STATIC "user mymath static lib" ON)

if(MYMATH_STATIC)
add_library(mymath STATIC mymath.cpp)
else()
add_library(mymath SHARED mymath.cpp)
endif()

In this paper, the reference :CMake course , as for CMake The installation and testing of will be explained in the next chapter .

Function description

about CMake, There may be two functions ：xxxxx and target_xxxx. Let's say link_libraries and target_link_libraries To explain .
link_libraries： Global , namely ：CMake All modules of will add this library .
target_link_libraries： Targeted , Only the specified target contains the Library .
for example CMake Including multiple goals A and B, At this point, if you pass link_libraries(ws2_32 test) contain ws2_32.lib and test.lib that A and B These two libraries will be included . But if it goes through target_link_libraries(A PUBLIC ws2_32 test) Then at this time, only the goal A Contains these two libraries .