Use CMake to build complex projects and cmake to build projects

Use CMake to build complex projects and cmake to build projects

0. What is CMake?

CMake is a cross-platform compilation, installation, testing, and packaging tool. CMake does not directly compile the software, but builds the software with the native build system. The cmakeconfiguration file is a cmakelist.txt file (each source code folder must have one). CMake generates Unix makefiles or VS solution files based on the configuration file.

1. Why CMake?

I don't know why others choose CMake. I am because it is too painful to directly write Makefile on Linux, and the project will be cross-platform.

2. Use a simple project to describe CMake usage.

• Project name soTest, which contains two so (dll) files: so1 and so2, and a test project st
• The file structure in the project is as follows:
  • File so1/so1.c: used to generate libso1.so
  • File so2/so2.c: used to generate libso2.so, dependent on libso1.so, will call the libso1.so Function
  • File test/test. c: generate an executable file, call libso2.so, and call the functions in libso2.so.
  • File test/test. py: Use python to call the libso2.so Function
  • The build directory is used to store the Compilation Time and files, so that the source code folder can be kept clean.
  • File structure
  • Each directory contains a cmakelist.txt file, which is the configuration file of CMake. CMake generates other build files based on these files.

3. The project code is as follows:

　　

1 // so1/so1.c2 int add_fun(int a, int b)3 {4     return a+b;5 }

1 // so1.h2 #ifndef _so1_h_3 #define _so1_h_4 5 int add_fun(int a, int b);6 int fun_test(int a);7 8 #endif//_so1_h_

 1 // so2/so2.h 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include "so1.h" 5  6 int fun_test(int a) 7 { 8     for (int i=0; i<a; ++i) 9     {10         printf("add_fun(%d+%d)=%d\n", i, i, add_fun(i, i));11     }12     13     return 0;14 }

 1 // test/test.c 2 #include <stdio.h> 3 #include <stdlib.h> 4  5 #include "so1.h" 6  7 int main(int argc, char **argv) 8 { 9     return fun_test(9);10 }

1 #. /CMakeLists.txt, project configuration file 2 3 # minimum VERSION requirements, must be 4 cmake_minimum_required (VERSION 3.0) 5 6 # project name, here use soTest name 7 project (soTest) 8 9 # Add the include directory. In this example, close the file in. /, so take ${PROJECT_SOURCE_DIR}/10 include_directories ($ {PROJECT_SOURCE_DIR}/) 11 12 # Add the link library to find the directory, query 13 link_directories ($ {PROJECT_BINARY_DIR}/libs/usr. local/libs/usr/lib) 14 15 # set the generated library file directory. Here we set 16 sets (LIBRARY_OUTPUT_PATH $ {PROJECT_BINARY_DIR}/libs) as the same as the library directory) 17 18 # set the executable file directory. 19 sets (EXECUTABLE_OUTPUT_PATH $ {PROJECT_BINARY_DIR}/libs) 20 21 # Add file 22 add_subdirectory (so1) 23 add_subdirectory (so2) 24 add_subdirectory (test)

# ./so1/CMakeLists.txt# project name: soTestproject(soTest)# set source filesset(so1 so1.c)# set make to a shared libraryadd_library(so1 SHARED ${so1})

 1 # ./so2/CMakeLists.txt 2  3 project(soTest) 4 set(so2 so2.c) 5 add_library(so2 SHARED ${so2}) 6  7 # link so1 8 target_link_libraries(so2 so1)

1 project (soTest) 2 set (st test. c) 3 4 # generate the executable file 5 add_executable (st test. c) 6 target_link_libraries (st so2 so1)

4. CMake supports building out of the source file directory. Here we select the directory where the./keystore file is located ):

cmake .. && make && ./libs/st

After the command is run, the result is as follows: