CMake Tutorial: Building and Managing Projects

1. Macro Functions

PROJECT_SOURCE_DIR

The directory immediately following the cmake command, usually the root directory of the project

PROJECT_BINARY_DIR

The directory where the cmake command is executed

CMAKE_CURRENT_SOURCE_DIR

The path where the current CMakeLists.txt being processed is located

CMAKE_CURRENT_BINARY_DIR

The compilation directory

EXECUTABLE_OUTPUT_PATH

Redefines the storage location for the target binary executable file

LIBRARY_OUTPUT_PATH

Redefines the storage location for the target link library files

PROJECT_NAME

Returns the project name defined by the PROJECT command

CMAKE_BINARY_DIR

The actual build path of the project; assuming the build is done in the build directory, this will be the path of that directory

2. Common Commands

CMake uses # for line comments, which can be placed anywhere.

CMake uses #[[ ]] for block comments.

Specify the minimum version of CMake to use

cmake_minimum_required

Define that the project will generate an executable program

add_executable(executable_name source_file_name)

Specify the C++ standard to use

set(CMAKE_CXX_STANDARD 11)

Define a variable

SET(VAR [VALUE] [CACHE TYPE DOCSTRING [FORCE]])

set(SRC_LIST add.c div.c main.c mult.c sub.c)

set(SRC_LIST add.c;div.c;main.c;mult.c;sub.c)

add_executable(app ${SRC_LIST})

Specify the output path

set(HOME /home/robin/Linux/Sort)

set(EXECUTABLE_OUTPUT_PATH ${HOME}/bin)

Find all source files in a given path

aux_source_directory(

aux_source_directory(${CMAKE_CURRENT_SOURCE_DIR}/src SRC_LIST)

add_executable(app ${SRC_LIST})

file(GLOB/GLOB_RECURSE variable_name file_path_and_file_type)

file(GLOB MAIN_SRC ${CMAKE_CURRENT_SOURCE_DIR}/src/*.cpp)

file(GLOB MAIN_HEAD ${CMAKE_CURRENT_SOURCE_DIR}/include/*.h)

Include header files

include_directories(headpath)

include_directories(${PROJECT_SOURCE_DIR}/include)

Create a static library

add_library(library_name STATIC source_file1 [source_file2] …)

Create a dynamic library

add_library(library_name SHARED source_file1 [source_file2] …)

Specify the output path for static and dynamic libraries

set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)

Include static library files

link_libraries( […])

link_directories()

link_directories(${PROJECT_SOURCE_DIR}/lib)

link_libraries(calc)

Include dynamic library files

target_link_libraries(A B C)

target_link_libraries(D A)

target_link_libraries(app pthread)

Macro Definitions

add_definitions(-Dmacro_name)

3. Examples

3.1 Single Source File

#include <stdio.h>#include <stdlib.h>/** * power - Calculate the power of number. * @param base: Base value. * @param exponent: Exponent value. * * @return base raised to the power exponent. */double power(double base, int exponent){    int result = base;    int i;        if (exponent == 0) {        return 1;    }        for(i = 1; i < exponent; ++i){        result = result * base;    }    return result;}int main(int argc, char *argv[]){    if (argc < 3){        printf("Usage: %s base exponent \n", argv[0]);        return 1;    }    double base = atof(argv[1]);    int exponent = atoi(argv[2]);    double result = power(base, exponent);    printf("%g ^ %d is %g\n", base, exponent, result);    return 0;}

Step Two: Write the CMakeLists.txt file and save it in the same directory as main.cc source file:

# CMake minimum version requiredcmake_minimum_required (VERSION 2.8)# Project informationproject (Demo1)# Specify the target to generateadd_executable(Demo main.cc)

Note:

• cmake .. indicates looking for the CMakeLists.txt file in the parent directory.

• cmake . indicates looking for the CMakeLists.txt file in the current directory.

Step One: Write the source code. The demo2 folder contains three files: main.c, MathFunctions.c, and MathFunctions.h.

Step Two: Write the CMakeLists.txt file and save it in the same directory as main.cc source file:

# CMake minimum version requiredcmake_minimum_required (VERSION 2.8)# Project informationproject (Demo2)# Specify the target to generateadd_executable(Demo main.cc MathFunctions.cc)

Find all source files in the specified directory

# CMake minimum version requiredcmake_minimum_required (VERSION 2.8)# Project informationproject (Demo2)# Find all source files in the current directory# and save the names to the DIR_SRCS variableaux_source_directory(. DIR_SRCS)# Specify the target to generateadd_executable(Demo ${DIR_SRCS})

Step Three: Execute cmake .,

Step One: Write the source code. The demo3 folder contains a file main.c and a folder math, the math folder contains two files: MathFunctions.c and MathFunctions.h.

# CMake minimum version requiredcmake_minimum_required (VERSION 2.8)# Project informationproject (Demo3)# Find all source files in the current directory# and save the names to the DIR_SRCS variableaux_source_directory(. DIR_SRCS)# Add math subdirectoryadd_subdirectory(math)# Specify the target to generate add_executable(Demo main.cc)# Add link librarytarget_link_libraries(Demo MathFunctions)