常用指令

• project <project_name> - Set the name of the project.

  Additionally this sets the variables <project_name>_SOURCE_DIR and <project_name>_BINARY_DIR to the respective values.

• cmake_minimum_required(VERSION major[.minor[.patch]]) - Set the minimim required version of cmake.

• aux_source_directory(<dir> <variable>) - 收集指定目录下的所有源文件.

  Collects the names of all source files in the specified directory and stores the list in the <variable> provided.

• add_executable(<name> source1 source2 ... sourceN) - Add an executable target.

  Adds an executable target called to be built from the source files listed in the command invocation. The corresponds to the logical target name and must be globally unique within a project.

• add_library(<name> [STATIC | SHARED | MODULE] source1 source2 ...... sourceN) - Add a library target.

  Add a library target called to be built from the source files listed in the command invovation. The corresponds to the logical target name and must be globally unique within a project.

• add_subdirectory(source_dir [binary_dir]) - Add a subdirectory to the build.

• message - Display a message to the user.

  message([<mode>] "message to display ...")

  The optional keyword determines the type of message:

  • (none) = Important information
  • STATUS = Incidental information(显示时，前缀为-)
  • WARNING = CMake Warning, continue processing
  • FATAL_ERROR = CMake Error, stop processing and generation

• set_target_properties - 设置构建目标(executable或library)的属性.

  Targets can have properties that affect how they are built.

  set_target_properties(target1 target2 ...
                        PROPERTIES prop1 value1
                                   prop2 value2
                                   ...)
  

  Set properties on a target. The syntax for the command is to list all the files you want to change, and then provide the values you want to set next. You can use any prop value pair you want and extract it later with the get_target_property command.

  常用的属性:

  • OUTPUT_NAME

    Sets the real name of a target when it is built.

  • LINK_FLAGS

    The LINK_FLAGS property can be used to add extra flags to the link step of a target.

  • COMPILE_FLAGS

    The COMPILE_FLAGS property sets addtional compiler flags used to build sources within the target. It may also used to pass addtional preprocessor definitions.

  • VERSION and SOVERSION

    For shared libraries VERSION and SOVERSION can be used to specify the build version and API version respectively. When building or installing appropriate symlinks are created if the platform supports symlinks and the linker support so-names. If only one of both is specified the missing is assumed to have the same version number. For executables VERSION can be used to specify the build version. When building or installing appropriate symlinks are created if the platform support symlinks.

• get_target_property - Get a property from a target.

  get_target_property(var target property)
  

• include_directories - Add include directories to the build(添加头文件的包含路径).

  include_directories([AFTER | BEFORE] dir1 dir2 ...)
  

  By default the directories are appended onto the current list directories. By using BEFORE or AFTER you can select between appending or prepending, independent from th default.

• link_directories - Specify directories in which the linker will look for libraries(添加链接库的路径).

  link_directories(directory1 directory2 ...)
  

  The command will apply only to targets created after is is called.

• link_libraries - Link libraries to all targets added later.

  link_libraries(lib1 lib2 ...)
  

• target_link_libraries - 指定构建目标要链接的库.

  Specify libraries or flags to use when linking a given target and/or its dependencies.

  target_link_libraries(target lib1 lib2 ...)
  

  The named <target> must have been created in the current directory by command such as add_executable or add_library.

• add_definitions - 为编译器定义宏或变量.

  add_definitions(-DFOO -DBAR -DVAR1=VALUE1 ...)
  

• add_dependencies - Add a dependency between top-level targets.

  定义目标的依赖, 确保依赖在目标之前构建.

  add_dependencies(<target> [<target-dependency>] ...)
  

  Make a top-level <target> depend on other top-level targets to ensure that they build before target> does. A top-level target is one created by one of the add_execute, add_library, or add_custom_target commmands.

• set - Set a normal, cache or environment variable to a given value.

  注解

  1. 变量的值设置为空, 表示unset this variable;
  2. 变量的值不只一个参数, 将这些组成一个list赋给变量.

  • Set Normal Variable

    set(<variable> <value> ...)
    

    Set the given variable in the current function or directory scope.

  • Set Cache Entry

    set(<variable> <value> ... CACHE <type> <docstring> [FORCE])
    

    定义CACHE变量, 可以跨作用域访问.

    The type must be specified as one of:

    • BOOL - Boolean ON/OFF value;
    • FILEPATH - Path to a file on disk;
    • PATH - Path to a directory on disk;
    • STRING - A line of text;
    • INTERNAL - A line of text.

    The <docstring> must be specified as a line of text providing a quick summary. 若同名的CACHE变量已经存在, 默认是不覆盖的; 如果设置了FORCE选项, 表示覆盖已存在的同名CACHE变量;

  • Set Envrionment Variable

    set(ENV{var} <value> ...)
    

    设置环境变量, cmake中对环境变量的读写需要用ENV{}包裹;

    • 取环境变量的值: $ENV{var};
    • if 判断时, 使用 ENV{var}, 不用加 $.

• unset - Unset a variable, cache variable, or environment variable.

• include - Load and run CMake code from a file or module(包含其它的cmake脚本).

  include(<file | module>)
  

  载入并运行CMakeLists.txt文件, 或cmake模块(cmake脚本).

• option - Provides an option that the user can optionally select.

  option(<option_variable> "help string describing option" [initial value])
  

  Provide an option for the user to select as ON or OFF. If no initial value is provided, OFF is used.

• file - File manipulation command.

  支持的操作有:

  • Reading
  • Writing
  • Filesystem
  • Path Conversion
  • Transfer
  • Locking

• string - String operations.

  支持的字符串操作有:

  • Search and Replace
  • Regular Expression
  • Manipulation
  • Comparision
  • Hashing
  • Generation

• configure_file - Copy a file to another location and modify its contents.

  configure_file(<input> <output> [COPYONLY] [@ONLY])
  

  Copies an <input> file to an <output> file and substitutes variables referenced as @VAR@ or ${VAR} in the input file content. Each variable reference will be replaced with current value of the variable, or the empty string if the variable is not defined.

  • COPYONLY

    Copy the file without replacing any variable references or other content.

  • @ONLY

    Restrict variable replacement to reference of the form @VAR@.

• set_property - Set a named property in a given scope.

• get_property - Get a property.

• execute_process - Execute one or more child processed.