Add include directories to a target.

target_include_directories(<target> [SYSTEM] [BEFORE]
  [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specify include directories or targets to use when compiling a given target. The named <target> must have been created by a command such as add_executable() or add_library() and must not be an IMPORTED target.

If BEFORE is specified, the content will be prepended to the property instead of being appended.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the following arguments. PRIVATE and PUBLIC items will populate the INCLUDE_DIRECTORIES property of <target>. PUBLIC and INTERFACE items will populate the INTERFACE_INCLUDE_DIRECTORIES property of <target>. The following arguments specify include directories.

Specified include directories may be absolute paths or relative paths. Repeated calls for the same <target> append items in the order called. If SYSTEM is specified, the compiler will be told the directories are meant as system include directories on some platforms (signalling this setting might achieve effects such as the compiler skipping warnings, or these fixed-install system files not being considered in dependency calculations - see compiler docs). If SYSTEM is used together with PUBLIC or INTERFACE, the INTERFACE_SYSTEM_INCLUDE_DIRECTORIES target property will be populated with the specified directories.

Arguments to target_include_directories may use “generator expressions” with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

Include directories usage requirements commonly differ between the build-tree and the install-tree. The BUILD_INTERFACE and INSTALL_INTERFACE generator expressions can be used to describe separate usage requirements based on the usage location. Relative paths are allowed within the INSTALL_INTERFACE expression and are interpreted relative to the installation prefix. For example:

target_include_directories(mylib PUBLIC
  $<INSTALL_INTERFACE:include/mylib>  # <prefix>/include/mylib