Reference
CMake is designed to be used in conjunction with the native build environment. configuration files placed in each source directory (called CMakeLists.txt files) are used to generate standard build files Makefile
CMakeLists.txt places
- Source folder
- Root of the source tree of any application, library
- For each module that can be compile and build separately
Hello cmake
- source
#include <iostream>
int main(void) {
std::cout << "Hello World" << std::endl;
return(0);
}
- CMakeLists.txt (with the source folder)
# Set the minimum required version of cmake for a project
cmake_minimum_required(VERSION 2.8)
# Project name
project(hello)
# Add an executable to the project using the specified source files
add_executable(hello hello.cpp)
- Run
cmake .
make
Build and bin sub folders
To keep files in place , and hold all cmake file in one place
mkdir build
cd build
cmake ..
make
Project structure
p1
├── bin
├── build
├── src
| └── CMakeLists.txt
└─ CMakeLists.txt
- Source CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
project(hello)
# Assign value to variable (make output folder)
set(EXECUTABLE_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/bin)
# Adds sub folder to build
add_subdirectory(src)
- Root src CMakeLists.txt
# Print message
message ("main application")
add_executable(hello test.cpp)
- from build sub folder
cmake ..
make
CMake variables
- Set variable data with
set function/macro - Access value with
${variable_name}
set(CMAKE_CXX_STANDARD 11)
message("CXX Standard:" ${CMAKE_CXX_STANDARD})
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
- Custom variables
set(TRIAL_VARIABLE "VALUE")
message("${TRIAL_VARIABLE}")
Building a Library with cmake
- Add lib/math sub folder under src
- Add header and source file
- Change main app to use the new functionality
code
- header file (src/lib/math/calc.hpp)
#ifndef CALC_HPP
#define CALC_HPP
namespace math {
class calc{
public:
int sum(const int &a, const int &b);
};
}
#endif
- implementation (src/lib/math/calc.cpp)
#include "calc.hpp"
int math::calc::sum(const int &a, const int &b){
return a + b;
}
- main
#include <iostream>
#include "lib/math/calc.hpp"
using namespace std;
int main(void) {
math::calc calc;
int sum = calc.sum(3, 4);
cout << "3+4=" << sum << endl;
return(0);
}
- CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
project(hello)
# set(CMAKE_BINARY_DIR ${CMAKE_SOURCE_DIR}/bin)
set(EXECUTABLE_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/bin)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/lib)
# CMAKE_ARCHIVE_OUTPUT_DIRECTORY
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
add_subdirectory(src)
- CMakeLists.txt (src)
# create shared library
add_library(math SHARED lib/math/calc.cpp)
add_executable(hello test.cpp)
# link libmath.so to executable
target_link_libraries(hello math)
- It's create shared library libxxx.so at
libsub folder - It's create binary use's the lib in
binsub folder
