Basic use of cmake

Preface

The company currently uses cmake, I haven't used it before , Take advantage of the intermission of the project to study , Take this as a record ;
This is a targeted study , So it is realized through various examples ;

cmake Specific use

One cpp File compiles an executable

File directory

among build Is a directory , It's to put cmake The file generated in the compilation process is isolated from the source file , This is it. cmake Recommended external build patterns ;

The contents of the document

main.cpp

#include <stdlib.h>
#include <stdio.h>

int main() {
    
	printf("cmake test\n");
	return 1;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.5) # Set up CMake Minimum version 
project (cmake_test) # Set the project name 
add_executable(${
    PROJECT_NAME} main.cpp) # Generate executable files    add_executable(cmake_test main.cpp)

compile

stay build Execute first under directory cmake3 …（ From build Go to the upper directory of CMakeLists.txt） To generate MakeFile file , The file directory after executing the command is as follows ：

And then build Execute under directory make command , For real compilation ：

make After execution , Can be in build I see it under the directory cmake_test Generation of executable files , This completes the goal ;
In the following example , By default, they are all created under the project directory build Directory and generate MakeFile File and generate executable —— Unless there are complications later , For example, when it is generated under the specified directory ;

Multi level directory + Multiple cpp File generation executable file

File directory

You can see , Yes 2 individual cpp file （main.cpp + src/my_class_1.cpp） and 1 individual h file (include/my_class_1.h)

The contents of the document

include/my_class_1.h

#ifndef _MY_CLASS_1_H_
#define _MY_CLASS_1_H_

class My_Class_1 {
    
public:
	My_Class_1();
	~My_Class_1();
	void class1_func();
};

#endif

src/my_class_1.cpp

#include <iostream>
#include "my_class_1.h"
 
My_Class_1::My_Class_1() {
    
	std::cout << "My_Class_1::My_Class_1" << std::endl;
}

My_Class_1::~My_Class_1() {
    
	std::cout << "My_Class_1::~My_Class_1" << std::endl;
}

void My_Class_1::class1_func() {
    
	std::cout << "My_Class_1::class1_func==> " << std::endl;
}

main.cpp

#include <stdlib.h>
#include <stdio.h>

#include "my_class_1.h"

int main() {
    
	printf("cmake test\n");
	My_Class_1 my_class_1_obj;
	my_class_1_obj.class1_func();
	return 1;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.5) # Set up CMake Minimum version 

project (cmake_test) # Set the project name 

set(SOURCES main.cpp src/my_class_1.cpp) # Create a variable , Name is SOURCE. It contains all of cpp file .
# If you want to put all of the current directory cpp File unified compilation , have access to ： aux_source_directory(. SOURCES)
add_executable(${
    PROJECT_NAME} ${
    SOURCES}) # Generate an executable file with all the source files , Because it defines SOURCE Variable , So there is no need to list cpp The file 

target_include_directories(${
    PROJECT_NAME} PRIVATE ${
    PROJECT_SOURCE_DIR}/include) # Set the header file directory that needs to be included to generate this executable 

Multi level directory + Multiple cpp File generates dynamic library file and executable file respectively

File directory

Compared with the previous example , The file directory remains unchanged ;

The contents of the document

Compared with the previous example , have only CMakeLists.txt Has changed , Other unchanged items will not be explained ;
CMakeLists.txt

cmake_minimum_required(VERSION 3.5) # Set up CMake Minimum version 

project (cmake_test) # Set the project name 

#Create a library  hold my_class_1.cpp Compile into a dynamic library ( The name is ：libmyclass.so)
add_library(myclass SHARED src/my_class_1.cpp)

# Add the header file directory required for the compilation of this dynamic library 
target_include_directories(myclass PUBLIC ${
    PROJECT_SOURCE_DIR}/include)

# Generate executable files 
add_executable(${
    PROJECT_NAME} main.cpp)

# Link libraries and executables 
target_link_libraries(${
    PROJECT_NAME} PRIVATE myclass)

compile

To regenerate the MakeFile And compile , You can see in the build Generated in directory libmyclass.so Dynamic library ;

Generate dynamic library files and executable files in the specified directory

File directory

Compared with the previous example , The file directory remains unchanged ;

The contents of the document

Compared with the previous example , have only CMakeLists.txt Has changed , Other unchanged items will not be explained ;
CMakeLists.txt

cmake_minimum_required(VERSION 3.5) # Set up CMake Minimum version 

# Set the project name 
project (cmake_test) 

# Set the output directory of the executable 
SET(EXECUTABLE_OUTPUT_PATH ${
    PROJECT_SOURCE_DIR}/bin)

# Set the output directory of the library file 
SET(LIBRARY_OUTPUT_PATH ${
    PROJECT_SOURCE_DIR}/lib)

# Create a library  hold my_class_1.cpp Compile into a dynamic library ( The name is ：libmyclass.so)
add_library(myclass SHARED src/my_class_1.cpp)

# Add the header file directory required for the compilation of this dynamic library 
target_include_directories(myclass PUBLIC ${
    PROJECT_SOURCE_DIR}/include)

# Generate executable files 
add_executable(${
    PROJECT_NAME} main.cpp)

# Set dynamic link library Directory 
link_libraries(${
    PROJECT_SOURCE_DIR}/lib)

# Link libraries and executables 
target_link_libraries(${
    PROJECT_NAME} PRIVATE myclass)

Compared with the previous example , It only specifies the directory for generating dynamic libraries and executable files ： The dynamic library is in the project directory lib Under the table of contents , The executable file is in bin Under the table of contents ; The setting is realized through the following two sentences ：

# Set the output directory of the executable 
SET(EXECUTABLE_OUTPUT_PATH ${
    PROJECT_SOURCE_DIR}/bin)

# Set the output directory of the library file 
SET(LIBRARY_OUTPUT_PATH ${
    PROJECT_SOURCE_DIR}/lib)

Reference resources

RoboMaster Visual tutorial CMake