New in version 3.1.

Add sources to a target.

  [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])

Specifies sources to use when building a target and/or its dependents. The named <target> must have been created by a command such as add_executable() or add_library() or add_custom_target() and must not be an ALIAS target. The <items> may use generator expressions.

New in version 3.20: <target> can be a custom target.

The INTERFACE, PUBLIC and PRIVATE keywords are required to specify the scope of the source file paths (<items>) that follow them. PRIVATE and PUBLIC items will populate the SOURCES property of <target>, which are used when building the target itself. PUBLIC and INTERFACE items will populate the INTERFACE_SOURCES property of <target>, which are used when building dependents. A target created by add_custom_target() can only have PRIVATE scope.

Repeated calls for the same <target> append items in the order called.

New in version 3.3: Allow exporting targets with INTERFACE_SOURCES.

New in version 3.11: Allow setting INTERFACE items on IMPORTED targets.

Changed in version 3.13: Relative source file paths are interpreted as being relative to the current source directory (i.e. CMAKE_CURRENT_SOURCE_DIR). See policy CMP0076.

A path that begins with a generator expression is left unmodified. When a target's SOURCE_DIR property differs from CMAKE_CURRENT_SOURCE_DIR, use absolute paths in generator expressions to ensure the sources are correctly assigned to the target.

# WRONG: starts with generator expression, but relative path used
target_sources(MyTarget PRIVATE "$<$<CONFIG:Debug>:dbgsrc.cpp>")

# CORRECT: absolute path used inside the generator expression
target_sources(MyTarget PRIVATE "$<$<CONFIG:Debug>:${CMAKE_CURRENT_SOURCE_DIR}/dbgsrc.cpp>")

See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

File Sets

New in version 3.23.

   [FILE_SET <set> [TYPE <type>] [BASE_DIRS <dirs>...] [FILES <files>...]]...

Adds a file set to a target, or adds files to an existing file set. Targets have zero or more named file sets. Each file set has a name, a type, a scope of INTERFACE, PUBLIC, or PRIVATE, one or more base directories, and files within those directories. The acceptable types include:


Sources intended to be used via a language's #include mechanism.


New in version 3.28.

Sources which contain C++ interface module or partition units (i.e., those using the export keyword). This file set type may not have an INTERFACE scope except on IMPORTED targets.

The optional default file sets are named after their type. The target may not be a custom target or FRAMEWORK target.

Files in a PRIVATE or PUBLIC file set are marked as source files for the purposes of IDE integration. Additionally, files in HEADERS file sets have their HEADER_FILE_ONLY property set to TRUE. Files in an INTERFACE or PUBLIC file set can be installed with the install(TARGETS) command, and exported with the install(EXPORT) and export() commands.

Each target_sources(FILE_SET) entry starts with INTERFACE, PUBLIC, or PRIVATE and accepts the following arguments:

FILE_SET <set>

The name of the file set to create or add to. It must contain only letters, numbers and underscores. Names starting with a capital letter are reserved for built-in file sets predefined by CMake. The only predefined set names are those matching the acceptable types. All other set names must not start with a capital letter or underscore.

TYPE <type>

Every file set is associated with a particular type of file. Only types specified above may be used and it is an error to specify anything else. As a special case, if the name of the file set is one of the types, the type does not need to be specified and the TYPE <type> arguments can be omitted. For all other file set names, TYPE is required.

BASE_DIRS <dirs>...

An optional list of base directories of the file set. Any relative path is treated as relative to the current source directory (i.e. CMAKE_CURRENT_SOURCE_DIR). If no BASE_DIRS are specified when the file set is first created, the value of CMAKE_CURRENT_SOURCE_DIR is added. This argument supports generator expressions.

No two base directories for a file set may be sub-directories of each other. This requirement must be met across all base directories added to a file set, not just those within a single call to target_sources().

FILES <files>...

An optional list of files to add to the file set. Each file must be in one of the base directories, or a subdirectory of one of the base directories. This argument supports generator expressions.

If relative paths are specified, they are considered relative to CMAKE_CURRENT_SOURCE_DIR at the time target_sources() is called. An exception to this is a path starting with $<. Such paths are treated as relative to the target's source directory after evaluation of generator expressions.

The following target properties are set by target_sources(FILE_SET), but they should not generally be manipulated directly:

For file sets of type HEADERS:

For file sets of type CXX_MODULES:

Target properties related to include directories are also modified by target_sources(FILE_SET) as follows:


If the TYPE is HEADERS, and the scope of the file set is PRIVATE or PUBLIC, all of the BASE_DIRS of the file set are wrapped in $<BUILD_INTERFACE> and appended to this property.


If the TYPE is HEADERS, and the scope of the file set is INTERFACE or PUBLIC, all of the BASE_DIRS of the file set are wrapped in $<BUILD_INTERFACE> and appended to this property.

See Also