CMake¶

Example 1¶

./hello.c

#include <stdio.h>

int main () {
  printf("Hello World!\n");
  return 0;
}

./CMakeLists.txt

PROJECT (HELLO)
SET (HELLO_SRCS hello.c)
ADD_EXECUTABLE (hello ${HELLO_SRCS})

編譯並執行

$ cmake .
-- The C compiler identification is GNU 5.1.0
-- The CXX compiler identification is GNU 5.1.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/cmake
$ make
Scanning dependencies of target hello
[100%] Building C object CMakeFiles/hello.dir/hello.c.o
Linking C executable hello
[100%] Built target hello
$ ./hello
Hello World!

Example 2¶

./lib/hello.c

#include <stdio.h>

void hello (){
    printf("Hello World!\n");
}

./lib/hello.h

void hello ();

./src/main.c

#include <hello.h>

int main () {
    hello();
    return 0;
}

./lib/CMakeLists.txt

ADD_LIBRARY (hello hello.c)

./src/CMakeLists.txt

INCLUDE_DIRECTORIES (${HELLO_SOURCE_DIR}/lib)
LINK_DIRECTORIES (${HELLO_BINARY_DIR}/lib)
ADD_EXECUTABLE (main main.c)
TARGET_LINK_LIBRARIES (main hello)

./CMakeLists.txt

PROJECT (HELLO)
ADD_SUBDIRECTORY (lib)
ADD_SUBDIRECTORY (src)

編譯並執行

$ cmake .
-- The C compiler identification is GNU 5.1.0
-- The CXX compiler identification is GNU 5.1.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/dv/cmake_zone
$ make
Scanning dependencies of target hello
[ 50%] Building C object lib/CMakeFiles/hello.dir/hello.o
Linking C static library libhello.a
[ 50%] Built target hello
Scanning dependencies of target main
[100%] Building C object src/CMakeFiles/main.dir/main.o
Linking C executable main
[100%] Built target main
$ src/main
Hello World!

More Options¶

指定安裝路徑¶

把原本的

$ cmake .

換成

$ cmake -DCMAKE_INSTALL_PREFIX:PATH=/your/install/path .

指定產生檔案的資料夾 (不要混在 source code 裡)¶

直接在想要放的 folder 下 cmake (接 source code 資料夾)

例如：

$ mkdir build
$ cd build
$ cmake ../

換 Linker¶

預設狀況下， Linker 會去找 Compiler 來用，例如 C++ 的會設成這樣 :

if(NOT CMAKE_CXX_LINK_EXECUTABLE)
  set(CMAKE_CXX_LINK_EXECUTABLE
      "<CMAKE_CXX_COMPILER>  <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> <LINK_LIBRARIES>")
endif()

也就是說會去找 C++ Compiler 來用，如果自己要換 Linker 的話就要把這個值蓋掉，例如在下 cmake 指令時加上參數 :

$ cmake \
-DCMAKE_LINKER=`which my_linker` \
-DCMAKE_CXX_LINK_EXECUTABLE='<CMAKE_LINKER> <FLAGS> <CMAKE_CXX_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>'