summaryrefslogtreecommitdiff
path: root/Help/command/add_library.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Help/command/add_library.rst')
-rw-r--r--Help/command/add_library.rst165
1 files changed, 165 insertions, 0 deletions
diff --git a/Help/command/add_library.rst b/Help/command/add_library.rst
new file mode 100644
index 000000000..de5335eff
--- /dev/null
+++ b/Help/command/add_library.rst
@@ -0,0 +1,165 @@
+add_library
+-----------
+
+.. only:: html
+
+ .. contents::
+
+Add a library to the project using the specified source files.
+
+Normal Libraries
+^^^^^^^^^^^^^^^^
+
+::
+
+ add_library(<name> [STATIC | SHARED | MODULE]
+ [EXCLUDE_FROM_ALL]
+ source1 [source2 ...])
+
+Adds a library target called ``<name>`` to be built from the source files
+listed in the command invocation. The ``<name>`` corresponds to the
+logical target name and must be globally unique within a project. The
+actual file name of the library built is constructed based on
+conventions of the native platform (such as ``lib<name>.a`` or
+``<name>.lib``).
+
+``STATIC``, ``SHARED``, or ``MODULE`` may be given to specify the type of
+library to be created. ``STATIC`` libraries are archives of object files
+for use when linking other targets. ``SHARED`` libraries are linked
+dynamically and loaded at runtime. ``MODULE`` libraries are plugins that
+are not linked into other targets but may be loaded dynamically at runtime
+using dlopen-like functionality. If no type is given explicitly the
+type is ``STATIC`` or ``SHARED`` based on whether the current value of the
+variable :variable:`BUILD_SHARED_LIBS` is ``ON``. For ``SHARED`` and
+``MODULE`` libraries the :prop_tgt:`POSITION_INDEPENDENT_CODE` target
+property is set to ``ON`` automatically.
+A ``SHARED`` or ``STATIC`` library may be marked with the :prop_tgt:`FRAMEWORK`
+target property to create an OS X Framework.
+
+If a library does not export any symbols, it must not be declared as a
+``SHARED`` library. For example, a Windows resource DLL or a managed C++/CLI
+DLL that exports no unmanaged symbols would need to be a ``MODULE`` library.
+This is because CMake expects a ``SHARED`` library to always have an
+associated import library on Windows.
+
+By default the library file will be created in the build tree directory
+corresponding to the source tree directory in which the command was
+invoked. See documentation of the :prop_tgt:`ARCHIVE_OUTPUT_DIRECTORY`,
+:prop_tgt:`LIBRARY_OUTPUT_DIRECTORY`, and
+:prop_tgt:`RUNTIME_OUTPUT_DIRECTORY` target properties to change this
+location. See documentation of the :prop_tgt:`OUTPUT_NAME` target
+property to change the ``<name>`` part of the final file name.
+
+If ``EXCLUDE_FROM_ALL`` is given the corresponding property will be set on
+the created target. See documentation of the :prop_tgt:`EXCLUDE_FROM_ALL`
+target property for details.
+
+Source arguments to ``add_library`` may use "generator expressions" with
+the syntax ``$<...>``. See the :manual:`cmake-generator-expressions(7)`
+manual for available expressions. See the :manual:`cmake-buildsystem(7)`
+manual for more on defining buildsystem properties.
+
+See also :prop_sf:`HEADER_FILE_ONLY` on what to do if some sources are
+pre-processed, and you want to have the original sources reachable from
+within IDE.
+
+Imported Libraries
+^^^^^^^^^^^^^^^^^^
+
+::
+
+ add_library(<name> <SHARED|STATIC|MODULE|OBJECT|UNKNOWN> IMPORTED
+ [GLOBAL])
+
+An :ref:`IMPORTED library target <Imported Targets>` references a library
+file located outside the project. No rules are generated to build it, and
+the :prop_tgt:`IMPORTED` target property is ``True``. The target name has
+scope in the directory in which it is created and below, but the ``GLOBAL``
+option extends visibility. It may be referenced like any target built
+within the project. ``IMPORTED`` libraries are useful for convenient
+reference from commands like :command:`target_link_libraries`. Details
+about the imported library are specified by setting properties whose names
+begin in ``IMPORTED_`` and ``INTERFACE_``. The most important such
+property is :prop_tgt:`IMPORTED_LOCATION` (and its per-configuration
+variant :prop_tgt:`IMPORTED_LOCATION_<CONFIG>`) which specifies the
+location of the main library file on disk. See documentation of the
+``IMPORTED_*`` and ``INTERFACE_*`` properties for more information.
+
+Object Libraries
+^^^^^^^^^^^^^^^^
+
+::
+
+ add_library(<name> OBJECT <src>...)
+
+Creates an :ref:`Object Library <Object Libraries>`. An object library
+compiles source files but does not archive or link their object files into a
+library. Instead other targets created by :command:`add_library` or
+:command:`add_executable` may reference the objects using an expression of the
+form ``$<TARGET_OBJECTS:objlib>`` as a source, where ``objlib`` is the
+object library name. For example:
+
+.. code-block:: cmake
+
+ add_library(... $<TARGET_OBJECTS:objlib> ...)
+ add_executable(... $<TARGET_OBJECTS:objlib> ...)
+
+will include objlib's object files in a library and an executable
+along with those compiled from their own sources. Object libraries
+may contain only sources that compile, header files, and other files
+that would not affect linking of a normal library (e.g. ``.txt``).
+They may contain custom commands generating such sources, but not
+``PRE_BUILD``, ``PRE_LINK``, or ``POST_BUILD`` commands. Object libraries
+cannot be linked. Some native build systems may not like targets that
+have only object files, so consider adding at least one real source file
+to any target that references ``$<TARGET_OBJECTS:objlib>``.
+
+Alias Libraries
+^^^^^^^^^^^^^^^
+
+::
+
+ add_library(<name> ALIAS <target>)
+
+Creates an :ref:`Alias Target <Alias Targets>`, such that ``<name>`` can be
+used to refer to ``<target>`` in subsequent commands. The ``<name>`` does
+not appear in the generated buildsystem as a make target. The ``<target>``
+may not be an :ref:`Imported Target <Imported Targets>` or an ``ALIAS``.
+``ALIAS`` targets can be used as linkable targets and as targets to
+read properties from. They can also be tested for existence with the
+regular :command:`if(TARGET)` subcommand. The ``<name>`` may not be used
+to modify properties of ``<target>``, that is, it may not be used as the
+operand of :command:`set_property`, :command:`set_target_properties`,
+:command:`target_link_libraries` etc. An ``ALIAS`` target may not be
+installed or exported.
+
+Interface Libraries
+^^^^^^^^^^^^^^^^^^^
+
+::
+
+ add_library(<name> INTERFACE [IMPORTED [GLOBAL]])
+
+Creates an :ref:`Interface Library <Interface Libraries>`. An ``INTERFACE``
+library target does not directly create build output, though it may
+have properties set on it and it may be installed, exported and
+imported. Typically the ``INTERFACE_*`` properties are populated on
+the interface target using the commands:
+
+* :command:`set_property`,
+* :command:`target_link_libraries(INTERFACE)`,
+* :command:`target_include_directories(INTERFACE)`,
+* :command:`target_compile_options(INTERFACE)`,
+* :command:`target_compile_definitions(INTERFACE)`, and
+* :command:`target_sources(INTERFACE)`,
+
+and then it is used as an argument to :command:`target_link_libraries`
+like any other target.
+
+An ``INTERFACE`` :ref:`Imported Target <Imported Targets>` may also be
+created with this signature. An ``IMPORTED`` library target references a
+library defined outside the project. The target name has scope in the
+directory in which it is created and below, but the ``GLOBAL`` option
+extends visibility. It may be referenced like any target built within
+the project. ``IMPORTED`` libraries are useful for convenient reference
+from commands like :command:`target_link_libraries`.