# add_custom_target

Add a target with no output so it will always be built.

    add_custom_target(Name [ALL] [command1 [args1...]]
                      [COMMAND command2 [args2...] ...]
                      [DEPENDS depend depend depend ... ]
                      [BYPRODUCTS [files...]]
                      [WORKING_DIRECTORY dir]
                      [COMMENT comment]
                      [VERBATIM] [USES_TERMINAL]
                      [COMMAND_EXPAND_LISTS]
                      [SOURCES src1 [src2...]])

Adds a target with the given name that executes the given commands. The target has no output file and is always considered out of date even if the commands try to create a file with the name of the target. Use the `add_custom_command()` command to generate a file with dependencies. By default nothing depends on the custom target. Use the `add_dependencies()` command to add dependencies to or from other targets.

The options are:

`ALL`
  Indicate that this target should be added to the default build target so that it will be run every time (the command cannot be called `ALL`).
`BYPRODUCTS`

  Specify the files the command is expected to produce but whose modification time may or may not be updated on subsequent builds. If a byproduct name is a relative path it will be interpreted relative to the build tree directory corresponding to the current source directory. Each byproduct file will be marked with the `GENERATED` source file property automatically.

  Explicit specification of byproducts is supported by the `Ninja` generator to tell the `ninja` build tool how to regenerate byproducts when they are missing. It is also useful when other build rules (e.g. custom commands) depend on the byproducts. Ninja requires a build rule for any generated file on which another rule depends even if there are order-only dependencies to ensure the byproducts will be available before their dependents build.

  The `BYPRODUCTS` option is ignored on non-Ninja generators except to mark byproducts `GENERATED`.

`COMMAND`

  Specify the command-line(s) to execute at build time. If more than one `COMMAND` is specified they will be executed in order, but not necessarily composed into a stateful shell or batch script. (To run a full script, use the `configure_file()` command or the `file(GENERATE)` command to create it, and then specify a `COMMAND` to launch it.)

  If `COMMAND` specifies an executable target name (created by the `add_executable()` command) it will automatically be replaced by the location of the executable created at build time. If set, the `CROSSCOMPILING_EMULATOR` executable target property will also be prepended to the command to allow the executable to run on the host. Additionally a target-level dependency will be added so that the executable target will be built before this custom target.

  Arguments to `COMMAND` may use `generator expressions`. References to target names in generator expressions imply target-level dependencies.

  The command and arguments are optional and if not specified an empty target will be created.

`COMMENT`
  Display the given message before the commands are executed at build time.
`DEPENDS`

  Reference files and outputs of custom commands created with `add_custom_command()` command calls in the same directory (`CMakeLists.txt` file). They will be brought up to date when the target is built.

  Use the `add_dependencies()` command to add dependencies on other targets.

`COMMAND_EXPAND_LISTS`
  Lists in `COMMAND` arguments will be expanded, including those created with `generator expressions`, allowing `COMMAND` arguments such as `${CC} "-I$<JOIN:$<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>,;-I>" foo.cc` to be properly expanded.
`SOURCES`
  Specify additional source files to be included in the custom target. Specified source files will be added to IDE project files for convenience in editing even if they have no build rules.
`VERBATIM`
  All arguments to the commands will be escaped properly for the build tool so that the invoked command receives each argument unchanged. Note that one level of escapes is still used by the CMake language processor before `add_custom_target` even sees the arguments. Use of `VERBATIM` is recommended as it enables correct behavior. When `VERBATIM` is not given the behavior is platform specific because there is no protection of tool-specific special characters.
`USES_TERMINAL`
  The command will be given direct access to the terminal if possible. With the `Ninja` generator, this places the command in the `console` `pool`.
`WORKING_DIRECTORY`
  Execute the command with the given current working directory. If it is a relative path it will be interpreted relative to the build tree directory corresponding to the current source directory.