917 lines
37 KiB
CMake
917 lines
37 KiB
CMake
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
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# file Copyright.txt or https://cmake.org/licensing for details.
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#[=======================================================================[.rst:
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FetchContent
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------------------
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.. only:: html
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.. contents::
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Overview
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^^^^^^^^
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This module enables populating content at configure time via any method
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supported by the :module:`ExternalProject` module. Whereas
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:command:`ExternalProject_Add` downloads at build time, the
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``FetchContent`` module makes content available immediately, allowing the
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configure step to use the content in commands like :command:`add_subdirectory`,
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:command:`include` or :command:`file` operations.
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Content population details would normally be defined separately from the
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command that performs the actual population. Projects should also
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check whether the content has already been populated somewhere else in the
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project hierarchy. Typical usage would look something like this:
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.. code-block:: cmake
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FetchContent_Declare(
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googletest
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GIT_REPOSITORY https://github.com/google/googletest.git
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GIT_TAG release-1.8.0
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)
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FetchContent_GetProperties(googletest)
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if(NOT googletest_POPULATED)
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FetchContent_Populate(googletest)
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add_subdirectory(${googletest_SOURCE_DIR} ${googletest_BINARY_DIR})
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endif()
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When using the above pattern with a hierarchical project arrangement,
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projects at higher levels in the hierarchy are able to define or override
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the population details of content specified anywhere lower in the project
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hierarchy. The ability to detect whether content has already been
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populated ensures that even if multiple child projects want certain content
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to be available, the first one to populate it wins. The other child project
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can simply make use of the already available content instead of repeating
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the population for itself. See the
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:ref:`Examples <fetch-content-examples>` section which demonstrates
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this scenario.
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The ``FetchContent`` module also supports defining and populating
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content in a single call, with no check for whether the content has been
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populated elsewhere in the project already. This is a more low level
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operation and would not normally be the way the module is used, but it is
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sometimes useful as part of implementing some higher level feature or to
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populate some content in CMake's script mode.
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Declaring Content Details
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^^^^^^^^^^^^^^^^^^^^^^^^^
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.. command:: FetchContent_Declare
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.. code-block:: cmake
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FetchContent_Declare(<name> <contentOptions>...)
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The ``FetchContent_Declare()`` function records the options that describe
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how to populate the specified content, but if such details have already
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been recorded earlier in this project (regardless of where in the project
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hierarchy), this and all later calls for the same content ``<name>`` are
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ignored. This "first to record, wins" approach is what allows hierarchical
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projects to have parent projects override content details of child projects.
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The content ``<name>`` can be any string without spaces, but good practice
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would be to use only letters, numbers and underscores. The name will be
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treated case-insensitively and it should be obvious for the content it
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represents, often being the name of the child project or the value given
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to its top level :command:`project` command (if it is a CMake project).
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For well-known public projects, the name should generally be the official
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name of the project. Choosing an unusual name makes it unlikely that other
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projects needing that same content will use the same name, leading to
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the content being populated multiple times.
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The ``<contentOptions>`` can be any of the download or update/patch options
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that the :command:`ExternalProject_Add` command understands. The configure,
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build, install and test steps are explicitly disabled and therefore options
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related to them will be ignored. In most cases, ``<contentOptions>`` will
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just be a couple of options defining the download method and method-specific
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details like a commit tag or archive hash. For example:
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.. code-block:: cmake
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FetchContent_Declare(
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googletest
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GIT_REPOSITORY https://github.com/google/googletest.git
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GIT_TAG release-1.8.0
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)
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FetchContent_Declare(
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myCompanyIcons
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URL https://intranet.mycompany.com/assets/iconset_1.12.tar.gz
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URL_HASH 5588a7b18261c20068beabfb4f530b87
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)
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FetchContent_Declare(
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myCompanyCertificates
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SVN_REPOSITORY svn+ssh://svn.mycompany.com/srv/svn/trunk/certs
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SVN_REVISION -r12345
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)
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Populating The Content
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^^^^^^^^^^^^^^^^^^^^^^
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.. command:: FetchContent_Populate
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.. code-block:: cmake
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FetchContent_Populate( <name> )
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In most cases, the only argument given to ``FetchContent_Populate()`` is the
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``<name>``. When used this way, the command assumes the content details have
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been recorded by an earlier call to :command:`FetchContent_Declare`. The
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details are stored in a global property, so they are unaffected by things
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like variable or directory scope. Therefore, it doesn't matter where in the
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project the details were previously declared, as long as they have been
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declared before the call to ``FetchContent_Populate()``. Those saved details
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are then used to construct a call to :command:`ExternalProject_Add` in a
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private sub-build to perform the content population immediately. The
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implementation of ``ExternalProject_Add()`` ensures that if the content has
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already been populated in a previous CMake run, that content will be reused
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rather than repopulating them again. For the common case where population
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involves downloading content, the cost of the download is only paid once.
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An internal global property records when a particular content population
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request has been processed. If ``FetchContent_Populate()`` is called more
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than once for the same content name within a configure run, the second call
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will halt with an error. Projects can and should check whether content
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population has already been processed with the
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:command:`FetchContent_GetProperties` command before calling
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``FetchContent_Populate()``.
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``FetchContent_Populate()`` will set three variables in the scope of the
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caller; ``<lcName>_POPULATED``, ``<lcName>_SOURCE_DIR`` and
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``<lcName>_BINARY_DIR``, where ``<lcName>`` is the lowercased ``<name>``.
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``<lcName>_POPULATED`` will always be set to ``True`` by the call.
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``<lcName>_SOURCE_DIR`` is the location where the
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content can be found upon return (it will have already been populated), while
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``<lcName>_BINARY_DIR`` is a directory intended for use as a corresponding
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build directory. The main use case for the two directory variables is to
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call :command:`add_subdirectory` immediately after population, i.e.:
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.. code-block:: cmake
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FetchContent_Populate(FooBar ...)
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add_subdirectory(${foobar_SOURCE_DIR} ${foobar_BINARY_DIR})
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The values of the three variables can also be retrieved from anywhere in the
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project hierarchy using the :command:`FetchContent_GetProperties` command.
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A number of cache variables influence the behavior of all content population
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performed using details saved from a :command:`FetchContent_Declare` call:
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``FETCHCONTENT_BASE_DIR``
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In most cases, the saved details do not specify any options relating to the
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directories to use for the internal sub-build, final source and build areas.
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It is generally best to leave these decisions up to the ``FetchContent``
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module to handle on the project's behalf. The ``FETCHCONTENT_BASE_DIR``
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cache variable controls the point under which all content population
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directories are collected, but in most cases developers would not need to
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change this. The default location is ``${CMAKE_BINARY_DIR}/_deps``, but if
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developers change this value, they should aim to keep the path short and
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just below the top level of the build tree to avoid running into path
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length problems on Windows.
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``FETCHCONTENT_QUIET``
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The logging output during population can be quite verbose, making the
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configure stage quite noisy. This cache option (``ON`` by default) hides
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all population output unless an error is encountered. If experiencing
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problems with hung downloads, temporarily switching this option off may
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help diagnose which content population is causing the issue.
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``FETCHCONTENT_FULLY_DISCONNECTED``
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When this option is enabled, no attempt is made to download or update
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any content. It is assumed that all content has already been populated in
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a previous run or the source directories have been pointed at existing
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contents the developer has provided manually (using options described
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further below). When the developer knows that no changes have been made to
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any content details, turning this option ``ON`` can significantly speed up
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the configure stage. It is ``OFF`` by default.
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``FETCHCONTENT_UPDATES_DISCONNECTED``
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This is a less severe download/update control compared to
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``FETCHCONTENT_FULLY_DISCONNECTED``. Instead of bypassing all download and
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update logic, the ``FETCHCONTENT_UPDATES_DISCONNECTED`` only disables the
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update stage. Therefore, if content has not been downloaded previously,
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it will still be downloaded when this option is enabled. This can speed up
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the configure stage, but not as much as
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``FETCHCONTENT_FULLY_DISCONNECTED``. It is ``OFF`` by default.
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In addition to the above cache variables, the following cache variables are
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also defined for each content name (``<ucName>`` is the uppercased value of
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``<name>``):
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``FETCHCONTENT_SOURCE_DIR_<ucName>``
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If this is set, no download or update steps are performed for the specified
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content and the ``<lcName>_SOURCE_DIR`` variable returned to the caller is
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pointed at this location. This gives developers a way to have a separate
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checkout of the content that they can modify freely without interference
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from the build. The build simply uses that existing source, but it still
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defines ``<lcName>_BINARY_DIR`` to point inside its own build area.
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Developers are strongly encouraged to use this mechanism rather than
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editing the sources populated in the default location, as changes to
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sources in the default location can be lost when content population details
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are changed by the project.
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``FETCHCONTENT_UPDATES_DISCONNECTED_<ucName>``
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This is the per-content equivalent of
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``FETCHCONTENT_UPDATES_DISCONNECTED``. If the global option or this option
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is ``ON``, then updates will be disabled for the named content.
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Disabling updates for individual content can be useful for content whose
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details rarely change, while still leaving other frequently changing
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content with updates enabled.
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The ``FetchContent_Populate()`` command also supports a syntax allowing the
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content details to be specified directly rather than using any saved
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details. This is more low-level and use of this form is generally to be
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avoided in favour of using saved content details as outlined above.
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Nevertheless, in certain situations it can be useful to invoke the content
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population as an isolated operation (typically as part of implementing some
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other higher level feature or when using CMake in script mode):
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.. code-block:: cmake
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FetchContent_Populate( <name>
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[QUIET]
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[SUBBUILD_DIR <subBuildDir>]
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[SOURCE_DIR <srcDir>]
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[BINARY_DIR <binDir>]
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...
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)
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This form has a number of key differences to that where only ``<name>`` is
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provided:
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- All required population details are assumed to have been provided directly
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in the call to ``FetchContent_Populate()``. Any saved details for
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``<name>`` are ignored.
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- No check is made for whether content for ``<name>`` has already been
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populated.
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- No global property is set to record that the population has occurred.
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- No global properties record the source or binary directories used for the
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populated content.
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- The ``FETCHCONTENT_FULLY_DISCONNECTED`` and
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``FETCHCONTENT_UPDATES_DISCONNECTED`` cache variables are ignored.
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The ``<lcName>_SOURCE_DIR`` and ``<lcName>_BINARY_DIR`` variables are still
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returned to the caller, but since these locations are not stored as global
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properties when this form is used, they are only available to the calling
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scope and below rather than the entire project hierarchy. No
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``<lcName>_POPULATED`` variable is set in the caller's scope with this form.
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The supported options for ``FetchContent_Populate()`` are the same as those
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for :command:`FetchContent_Declare()`. Those few options shown just
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above are either specific to ``FetchContent_Populate()`` or their behavior is
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slightly modified from how :command:`ExternalProject_Add` treats them.
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``QUIET``
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The ``QUIET`` option can be given to hide the output associated with
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populating the specified content. If the population fails, the output will
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be shown regardless of whether this option was given or not so that the
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cause of the failure can be diagnosed. The global ``FETCHCONTENT_QUIET``
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cache variable has no effect on ``FetchContent_Populate()`` calls where the
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content details are provided directly.
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``SUBBUILD_DIR``
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The ``SUBBUILD_DIR`` argument can be provided to change the location of the
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sub-build created to perform the population. The default value is
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``${CMAKE_CURRENT_BINARY_DIR}/<lcName>-subbuild`` and it would be unusual
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to need to override this default. If a relative path is specified, it will
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be interpreted as relative to :variable:`CMAKE_CURRENT_BINARY_DIR`.
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``SOURCE_DIR``, ``BINARY_DIR``
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The ``SOURCE_DIR`` and ``BINARY_DIR`` arguments are supported by
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:command:`ExternalProject_Add`, but different default values are used by
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``FetchContent_Populate()``. ``SOURCE_DIR`` defaults to
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``${CMAKE_CURRENT_BINARY_DIR}/<lcName>-src`` and ``BINARY_DIR`` defaults to
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``${CMAKE_CURRENT_BINARY_DIR}/<lcName>-build``. If a relative path is
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specified, it will be interpreted as relative to
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:variable:`CMAKE_CURRENT_BINARY_DIR`.
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In addition to the above explicit options, any other unrecognized options are
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passed through unmodified to :command:`ExternalProject_Add` to perform the
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download, patch and update steps. The following options are explicitly
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prohibited (they are disabled by the ``FetchContent_Populate()`` command):
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- ``CONFIGURE_COMMAND``
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- ``BUILD_COMMAND``
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- ``INSTALL_COMMAND``
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- ``TEST_COMMAND``
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If using ``FetchContent_Populate()`` within CMake's script mode, be aware
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that the implementation sets up a sub-build which therefore requires a CMake
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generator and build tool to be available. If these cannot be found by
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default, then the :variable:`CMAKE_GENERATOR` and/or
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:variable:`CMAKE_MAKE_PROGRAM` variables will need to be set appropriately
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on the command line invoking the script.
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Retrieve Population Properties
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.. command:: FetchContent_GetProperties
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When using saved content details, a call to :command:`FetchContent_Populate`
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records information in global properties which can be queried at any time.
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This information includes the source and binary directories associated with
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the content and also whether or not the content population has been processed
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during the current configure run.
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.. code-block:: cmake
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FetchContent_GetProperties( <name>
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[SOURCE_DIR <srcDirVar>]
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[BINARY_DIR <binDirVar>]
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[POPULATED <doneVar>]
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)
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The ``SOURCE_DIR``, ``BINARY_DIR`` and ``POPULATED`` options can be used to
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specify which properties should be retrieved. Each option accepts a value
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which is the name of the variable in which to store that property. Most of
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the time though, only ``<name>`` is given, in which case the call will then
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set the same variables as a call to
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:command:`FetchContent_Populate(name) <FetchContent_Populate>`. This allows
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the following canonical pattern to be used, which ensures that the relevant
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variables will always be defined regardless of whether or not the population
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has been performed elsewhere in the project already:
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.. code-block:: cmake
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FetchContent_GetProperties(foobar)
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if(NOT foobar_POPULATED)
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FetchContent_Populate(foobar)
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# Set any custom variables, etc. here, then
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# populate the content as part of this build
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add_subdirectory(${foobar_SOURCE_DIR} ${foobar_BINARY_DIR})
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endif()
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The above pattern allows other parts of the overall project hierarchy to
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re-use the same content and ensure that it is only populated once.
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.. _`fetch-content-examples`:
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Examples
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^^^^^^^^
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Consider a project hierarchy where ``projA`` is the top level project and it
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depends on projects ``projB`` and ``projC``. Both ``projB`` and ``projC``
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can be built standalone and they also both depend on another project
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``projD``. For simplicity, this example will assume that all four projects
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are available on a company git server. The ``CMakeLists.txt`` of each project
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might have sections like the following:
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*projA*:
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.. code-block:: cmake
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include(FetchContent)
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FetchContent_Declare(
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projB
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GIT_REPOSITORY git@mycompany.com/git/projB.git
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GIT_TAG 4a89dc7e24ff212a7b5167bef7ab079d
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)
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FetchContent_Declare(
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projC
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GIT_REPOSITORY git@mycompany.com/git/projC.git
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GIT_TAG 4ad4016bd1d8d5412d135cf8ceea1bb9
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)
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FetchContent_Declare(
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projD
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GIT_REPOSITORY git@mycompany.com/git/projD.git
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GIT_TAG origin/integrationBranch
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)
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FetchContent_GetProperties(projB)
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if(NOT projb_POPULATED)
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FetchContent_Populate(projB)
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add_subdirectory(${projb_SOURCE_DIR} ${projb_BINARY_DIR})
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endif()
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FetchContent_GetProperties(projC)
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if(NOT projc_POPULATED)
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FetchContent_Populate(projC)
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add_subdirectory(${projc_SOURCE_DIR} ${projc_BINARY_DIR})
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endif()
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*projB*:
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.. code-block:: cmake
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include(FetchContent)
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FetchContent_Declare(
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projD
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GIT_REPOSITORY git@mycompany.com/git/projD.git
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GIT_TAG 20b415f9034bbd2a2e8216e9a5c9e632
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)
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FetchContent_GetProperties(projD)
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if(NOT projd_POPULATED)
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FetchContent_Populate(projD)
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add_subdirectory(${projd_SOURCE_DIR} ${projd_BINARY_DIR})
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endif()
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*projC*:
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.. code-block:: cmake
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include(FetchContent)
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FetchContent_Declare(
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projD
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GIT_REPOSITORY git@mycompany.com/git/projD.git
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GIT_TAG 7d9a17ad2c962aa13e2fbb8043fb6b8a
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)
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FetchContent_GetProperties(projD)
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if(NOT projd_POPULATED)
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FetchContent_Populate(projD)
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add_subdirectory(${projd_SOURCE_DIR} ${projd_BINARY_DIR})
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endif()
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A few key points should be noted in the above:
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- ``projB`` and ``projC`` define different content details for ``projD``,
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but ``projA`` also defines a set of content details for ``projD`` and
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because ``projA`` will define them first, the details from ``projB`` and
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``projC`` will not be used. The override details defined by ``projA``
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are not required to match either of those from ``projB`` or ``projC``, but
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it is up to the higher level project to ensure that the details it does
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define still make sense for the child projects.
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- While ``projA`` defined content details for ``projD``, it did not need
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to explicitly call ``FetchContent_Populate(projD)`` itself. Instead, it
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leaves that to a child project to do (in this case it will be ``projB``
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since it is added to the build ahead of ``projC``). If ``projA`` needed to
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customize how the ``projD`` content was brought into the build as well
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(e.g. define some CMake variables before calling
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:command:`add_subdirectory` after populating), it would do the call to
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``FetchContent_Populate()``, etc. just as it did for the ``projB`` and
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``projC`` content. For higher level projects, it is usually enough to
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just define the override content details and leave the actual population
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to the child projects. This saves repeating the same thing at each level
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of the project hierarchy unnecessarily.
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- Even though ``projA`` is the top level project in this example, it still
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checks whether ``projB`` and ``projC`` have already been populated before
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going ahead to do those populations. This makes ``projA`` able to be more
|
|
easily incorporated as a child of some other higher level project in the
|
|
future if required. Always protect a call to
|
|
:command:`FetchContent_Populate` with a check to
|
|
:command:`FetchContent_GetProperties`, even in what may be considered a top
|
|
level project at the time.
|
|
|
|
|
|
The following example demonstrates how one might download and unpack a
|
|
firmware tarball using CMake's :manual:`script mode <cmake(1)>`. The call to
|
|
:command:`FetchContent_Populate` specifies all the content details and the
|
|
unpacked firmware will be placed in a ``firmware`` directory below the
|
|
current working directory.
|
|
|
|
*getFirmware.cmake*:
|
|
|
|
.. code-block:: cmake
|
|
|
|
# NOTE: Intended to be run in script mode with cmake -P
|
|
include(FetchContent)
|
|
FetchContent_Populate(
|
|
firmware
|
|
URL https://mycompany.com/assets/firmware-1.23-arm.tar.gz
|
|
URL_HASH MD5=68247684da89b608d466253762b0ff11
|
|
SOURCE_DIR firmware
|
|
)
|
|
|
|
#]=======================================================================]
|
|
|
|
|
|
set(__FetchContent_privateDir "${CMAKE_CURRENT_LIST_DIR}/FetchContent")
|
|
|
|
#=======================================================================
|
|
# Recording and retrieving content details for later population
|
|
#=======================================================================
|
|
|
|
# Internal use, projects must not call this directly. It is
|
|
# intended for use by FetchContent_Declare() only.
|
|
#
|
|
# Sets a content-specific global property (not meant for use
|
|
# outside of functions defined here in this file) which can later
|
|
# be retrieved using __FetchContent_getSavedDetails() with just the
|
|
# same content name. If there is already a value stored in the
|
|
# property, it is left unchanged and this call has no effect.
|
|
# This allows parent projects to define the content details,
|
|
# overriding anything a child project may try to set (properties
|
|
# are not cached between runs, so the first thing to set it in a
|
|
# build will be in control).
|
|
function(__FetchContent_declareDetails contentName)
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
set(propertyName "_FetchContent_${contentNameLower}_savedDetails")
|
|
get_property(alreadyDefined GLOBAL PROPERTY ${propertyName} DEFINED)
|
|
if(NOT alreadyDefined)
|
|
define_property(GLOBAL PROPERTY ${propertyName}
|
|
BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
|
|
FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
|
|
)
|
|
set_property(GLOBAL PROPERTY ${propertyName} ${ARGN})
|
|
endif()
|
|
|
|
endfunction()
|
|
|
|
|
|
# Internal use, projects must not call this directly. It is
|
|
# intended for use by the FetchContent_Declare() function.
|
|
#
|
|
# Retrieves details saved for the specified content in an
|
|
# earlier call to __FetchContent_declareDetails().
|
|
function(__FetchContent_getSavedDetails contentName outVar)
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
set(propertyName "_FetchContent_${contentNameLower}_savedDetails")
|
|
get_property(alreadyDefined GLOBAL PROPERTY ${propertyName} DEFINED)
|
|
if(NOT alreadyDefined)
|
|
message(FATAL_ERROR "No content details recorded for ${contentName}")
|
|
endif()
|
|
get_property(propertyValue GLOBAL PROPERTY ${propertyName})
|
|
set(${outVar} "${propertyValue}" PARENT_SCOPE)
|
|
|
|
endfunction()
|
|
|
|
|
|
# Saves population details of the content, sets defaults for the
|
|
# SOURCE_DIR and BUILD_DIR.
|
|
function(FetchContent_Declare contentName)
|
|
|
|
set(options "")
|
|
set(oneValueArgs SVN_REPOSITORY)
|
|
set(multiValueArgs "")
|
|
|
|
cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
|
|
|
|
unset(srcDirSuffix)
|
|
unset(svnRepoArgs)
|
|
if(ARG_SVN_REPOSITORY)
|
|
# Add a hash of the svn repository URL to the source dir. This works
|
|
# around the problem where if the URL changes, the download would
|
|
# fail because it tries to checkout/update rather than switch the
|
|
# old URL to the new one. We limit the hash to the first 7 characters
|
|
# so that the source path doesn't get overly long (which can be a
|
|
# problem on windows due to path length limits).
|
|
string(SHA1 urlSHA ${ARG_SVN_REPOSITORY})
|
|
string(SUBSTRING ${urlSHA} 0 7 urlSHA)
|
|
set(srcDirSuffix "-${urlSHA}")
|
|
set(svnRepoArgs SVN_REPOSITORY ${ARG_SVN_REPOSITORY})
|
|
endif()
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
__FetchContent_declareDetails(
|
|
${contentNameLower}
|
|
SOURCE_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-src${srcDirSuffix}"
|
|
BINARY_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-build"
|
|
${svnRepoArgs}
|
|
# List these last so they can override things we set above
|
|
${ARG_UNPARSED_ARGUMENTS}
|
|
)
|
|
|
|
endfunction()
|
|
|
|
|
|
#=======================================================================
|
|
# Set/get whether the specified content has been populated yet.
|
|
# The setter also records the source and binary dirs used.
|
|
#=======================================================================
|
|
|
|
# Internal use, projects must not call this directly. It is
|
|
# intended for use by the FetchContent_Populate() function to
|
|
# record when FetchContent_Populate() is called for a particular
|
|
# content name.
|
|
function(__FetchContent_setPopulated contentName sourceDir binaryDir)
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
set(prefix "_FetchContent_${contentNameLower}")
|
|
|
|
set(propertyName "${prefix}_sourceDir")
|
|
define_property(GLOBAL PROPERTY ${propertyName}
|
|
BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
|
|
FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
|
|
)
|
|
set_property(GLOBAL PROPERTY ${propertyName} ${sourceDir})
|
|
|
|
set(propertyName "${prefix}_binaryDir")
|
|
define_property(GLOBAL PROPERTY ${propertyName}
|
|
BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
|
|
FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
|
|
)
|
|
set_property(GLOBAL PROPERTY ${propertyName} ${binaryDir})
|
|
|
|
set(propertyName "${prefix}_populated")
|
|
define_property(GLOBAL PROPERTY ${propertyName}
|
|
BRIEF_DOCS "Internal implementation detail of FetchContent_Populate()"
|
|
FULL_DOCS "Details used by FetchContent_Populate() for ${contentName}"
|
|
)
|
|
set_property(GLOBAL PROPERTY ${propertyName} True)
|
|
|
|
endfunction()
|
|
|
|
|
|
# Set variables in the calling scope for any of the retrievable
|
|
# properties. If no specific properties are requested, variables
|
|
# will be set for all retrievable properties.
|
|
#
|
|
# This function is intended to also be used by projects as the canonical
|
|
# way to detect whether they should call FetchContent_Populate()
|
|
# and pull the populated source into the build with add_subdirectory(),
|
|
# if they are using the populated content in that way.
|
|
function(FetchContent_GetProperties contentName)
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
|
|
set(options "")
|
|
set(oneValueArgs SOURCE_DIR BINARY_DIR POPULATED)
|
|
set(multiValueArgs "")
|
|
|
|
cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
|
|
|
|
if(NOT ARG_SOURCE_DIR AND
|
|
NOT ARG_BINARY_DIR AND
|
|
NOT ARG_POPULATED)
|
|
# No specific properties requested, provide them all
|
|
set(ARG_SOURCE_DIR ${contentNameLower}_SOURCE_DIR)
|
|
set(ARG_BINARY_DIR ${contentNameLower}_BINARY_DIR)
|
|
set(ARG_POPULATED ${contentNameLower}_POPULATED)
|
|
endif()
|
|
|
|
set(prefix "_FetchContent_${contentNameLower}")
|
|
|
|
if(ARG_SOURCE_DIR)
|
|
set(propertyName "${prefix}_sourceDir")
|
|
get_property(value GLOBAL PROPERTY ${propertyName})
|
|
if(value)
|
|
set(${ARG_SOURCE_DIR} ${value} PARENT_SCOPE)
|
|
endif()
|
|
endif()
|
|
|
|
if(ARG_BINARY_DIR)
|
|
set(propertyName "${prefix}_binaryDir")
|
|
get_property(value GLOBAL PROPERTY ${propertyName})
|
|
if(value)
|
|
set(${ARG_BINARY_DIR} ${value} PARENT_SCOPE)
|
|
endif()
|
|
endif()
|
|
|
|
if(ARG_POPULATED)
|
|
set(propertyName "${prefix}_populated")
|
|
get_property(value GLOBAL PROPERTY ${propertyName} DEFINED)
|
|
set(${ARG_POPULATED} ${value} PARENT_SCOPE)
|
|
endif()
|
|
|
|
endfunction()
|
|
|
|
|
|
#=======================================================================
|
|
# Performing the population
|
|
#=======================================================================
|
|
|
|
# The value of contentName will always have been lowercased by the caller.
|
|
# All other arguments are assumed to be options that are understood by
|
|
# ExternalProject_Add(), except for QUIET and SUBBUILD_DIR.
|
|
function(__FetchContent_directPopulate contentName)
|
|
|
|
set(options
|
|
QUIET
|
|
)
|
|
set(oneValueArgs
|
|
SUBBUILD_DIR
|
|
SOURCE_DIR
|
|
BINARY_DIR
|
|
# Prevent the following from being passed through
|
|
CONFIGURE_COMMAND
|
|
BUILD_COMMAND
|
|
INSTALL_COMMAND
|
|
TEST_COMMAND
|
|
)
|
|
set(multiValueArgs "")
|
|
|
|
cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
|
|
|
|
if(NOT ARG_SUBBUILD_DIR)
|
|
message(FATAL_ERROR "Internal error: SUBBUILD_DIR not set")
|
|
elseif(NOT IS_ABSOLUTE "${ARG_SUBBUILD_DIR}")
|
|
set(ARG_SUBBUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/${ARG_SUBBUILD_DIR}")
|
|
endif()
|
|
|
|
if(NOT ARG_SOURCE_DIR)
|
|
message(FATAL_ERROR "Internal error: SOURCE_DIR not set")
|
|
elseif(NOT IS_ABSOLUTE "${ARG_SOURCE_DIR}")
|
|
set(ARG_SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/${ARG_SOURCE_DIR}")
|
|
endif()
|
|
|
|
if(NOT ARG_BINARY_DIR)
|
|
message(FATAL_ERROR "Internal error: BINARY_DIR not set")
|
|
elseif(NOT IS_ABSOLUTE "${ARG_BINARY_DIR}")
|
|
set(ARG_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/${ARG_BINARY_DIR}")
|
|
endif()
|
|
|
|
# Ensure the caller can know where to find the source and build directories
|
|
# with some convenient variables. Doing this here ensures the caller sees
|
|
# the correct result in the case where the default values are overridden by
|
|
# the content details set by the project.
|
|
set(${contentName}_SOURCE_DIR "${ARG_SOURCE_DIR}" PARENT_SCOPE)
|
|
set(${contentName}_BINARY_DIR "${ARG_BINARY_DIR}" PARENT_SCOPE)
|
|
|
|
# The unparsed arguments may contain spaces, so build up ARG_EXTRA
|
|
# in such a way that it correctly substitutes into the generated
|
|
# CMakeLists.txt file with each argument quoted.
|
|
unset(ARG_EXTRA)
|
|
foreach(arg IN LISTS ARG_UNPARSED_ARGUMENTS)
|
|
set(ARG_EXTRA "${ARG_EXTRA} \"${arg}\"")
|
|
endforeach()
|
|
|
|
# Hide output if requested, but save it to a variable in case there's an
|
|
# error so we can show the output upon failure. When not quiet, don't
|
|
# capture the output to a variable because the user may want to see the
|
|
# output as it happens (e.g. progress during long downloads). Combine both
|
|
# stdout and stderr in the one capture variable so the output stays in order.
|
|
if (ARG_QUIET)
|
|
set(outputOptions
|
|
OUTPUT_VARIABLE capturedOutput
|
|
ERROR_VARIABLE capturedOutput
|
|
)
|
|
else()
|
|
set(capturedOutput)
|
|
set(outputOptions)
|
|
message(STATUS "Populating ${contentName}")
|
|
endif()
|
|
|
|
if(CMAKE_GENERATOR)
|
|
set(generatorOpts "-G${CMAKE_GENERATOR}")
|
|
if(CMAKE_GENERATOR_PLATFORM)
|
|
list(APPEND generatorOpts "-A${CMAKE_GENERATOR_PLATFORM}")
|
|
endif()
|
|
if(CMAKE_GENERATOR_TOOLSET)
|
|
list(APPEND generatorOpts "-T${CMAKE_GENERATOR_TOOLSET}")
|
|
endif()
|
|
|
|
if(CMAKE_MAKE_PROGRAM)
|
|
list(APPEND generatorOpts "-DCMAKE_MAKE_PROGRAM:FILEPATH=${CMAKE_MAKE_PROGRAM}")
|
|
endif()
|
|
|
|
else()
|
|
# Likely we've been invoked via CMake's script mode where no
|
|
# generator is set (and hence CMAKE_MAKE_PROGRAM could not be
|
|
# trusted even if provided). We will have to rely on being
|
|
# able to find the default generator and build tool.
|
|
unset(generatorOpts)
|
|
endif()
|
|
|
|
# Create and build a separate CMake project to carry out the population.
|
|
# If we've already previously done these steps, they will not cause
|
|
# anything to be updated, so extra rebuilds of the project won't occur.
|
|
# Make sure to pass through CMAKE_MAKE_PROGRAM in case the main project
|
|
# has this set to something not findable on the PATH.
|
|
configure_file("${__FetchContent_privateDir}/CMakeLists.cmake.in"
|
|
"${ARG_SUBBUILD_DIR}/CMakeLists.txt")
|
|
execute_process(
|
|
COMMAND ${CMAKE_COMMAND} ${generatorOpts} .
|
|
RESULT_VARIABLE result
|
|
${outputOptions}
|
|
WORKING_DIRECTORY "${ARG_SUBBUILD_DIR}"
|
|
)
|
|
if(result)
|
|
if(capturedOutput)
|
|
message("${capturedOutput}")
|
|
endif()
|
|
message(FATAL_ERROR "CMake step for ${contentName} failed: ${result}")
|
|
endif()
|
|
execute_process(
|
|
COMMAND ${CMAKE_COMMAND} --build .
|
|
RESULT_VARIABLE result
|
|
${outputOptions}
|
|
WORKING_DIRECTORY "${ARG_SUBBUILD_DIR}"
|
|
)
|
|
if(result)
|
|
if(capturedOutput)
|
|
message("${capturedOutput}")
|
|
endif()
|
|
message(FATAL_ERROR "Build step for ${contentName} failed: ${result}")
|
|
endif()
|
|
|
|
endfunction()
|
|
|
|
|
|
option(FETCHCONTENT_FULLY_DISCONNECTED "Disables all attempts to download or update content and assumes source dirs already exist")
|
|
option(FETCHCONTENT_UPDATES_DISCONNECTED "Enables UPDATE_DISCONNECTED behavior for all content population")
|
|
option(FETCHCONTENT_QUIET "Enables QUIET option for all content population" ON)
|
|
set(FETCHCONTENT_BASE_DIR "${CMAKE_BINARY_DIR}/_deps" CACHE PATH "Directory under which to collect all populated content")
|
|
|
|
# Populate the specified content using details stored from
|
|
# an earlier call to FetchContent_Declare().
|
|
function(FetchContent_Populate contentName)
|
|
|
|
if(NOT contentName)
|
|
message(FATAL_ERROR "Empty contentName not allowed for FetchContent_Populate()")
|
|
endif()
|
|
|
|
string(TOLOWER ${contentName} contentNameLower)
|
|
|
|
if(ARGN)
|
|
# This is the direct population form with details fully specified
|
|
# as part of the call, so we already have everything we need
|
|
__FetchContent_directPopulate(
|
|
${contentNameLower}
|
|
SUBBUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/${contentNameLower}-subbuild"
|
|
SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/${contentNameLower}-src"
|
|
BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/${contentNameLower}-build"
|
|
${ARGN} # Could override any of the above ..._DIR variables
|
|
)
|
|
|
|
# Pass source and binary dir variables back to the caller
|
|
set(${contentNameLower}_SOURCE_DIR "${${contentNameLower}_SOURCE_DIR}" PARENT_SCOPE)
|
|
set(${contentNameLower}_BINARY_DIR "${${contentNameLower}_BINARY_DIR}" PARENT_SCOPE)
|
|
|
|
# Don't set global properties, or record that we did this population, since
|
|
# this was a direct call outside of the normal declared details form.
|
|
# We only want to save values in the global properties for content that
|
|
# honours the hierarchical details mechanism so that projects are not
|
|
# robbed of the ability to override details set in nested projects.
|
|
return()
|
|
endif()
|
|
|
|
# No details provided, so assume they were saved from an earlier call
|
|
# to FetchContent_Declare(). Do a check that we haven't already
|
|
# populated this content before in case the caller forgot to check.
|
|
FetchContent_GetProperties(${contentName})
|
|
if(${contentNameLower}_POPULATED)
|
|
message(FATAL_ERROR "Content ${contentName} already populated in ${${contentNameLower}_SOURCE_DIR}")
|
|
endif()
|
|
|
|
string(TOUPPER ${contentName} contentNameUpper)
|
|
set(FETCHCONTENT_SOURCE_DIR_${contentNameUpper}
|
|
"${FETCHCONTENT_SOURCE_DIR_${contentNameUpper}}"
|
|
CACHE PATH "When not empty, overrides where to find pre-populated content for ${contentName}")
|
|
|
|
if(FETCHCONTENT_SOURCE_DIR_${contentNameUpper})
|
|
# The source directory has been explicitly provided in the cache,
|
|
# so no population is required
|
|
set(${contentNameLower}_SOURCE_DIR "${FETCHCONTENT_SOURCE_DIR_${contentNameUpper}}")
|
|
set(${contentNameLower}_BINARY_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-build")
|
|
|
|
elseif(FETCHCONTENT_FULLY_DISCONNECTED)
|
|
# Bypass population and assume source is already there from a previous run
|
|
set(${contentNameLower}_SOURCE_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-src")
|
|
set(${contentNameLower}_BINARY_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-build")
|
|
|
|
else()
|
|
# Support both a global "disconnect all updates" and a per-content
|
|
# update test (either one being set disables updates for this content).
|
|
option(FETCHCONTENT_UPDATES_DISCONNECTED_${contentNameUpper}
|
|
"Enables UPDATE_DISCONNECTED behavior just for population of ${contentName}")
|
|
if(FETCHCONTENT_UPDATES_DISCONNECTED OR
|
|
FETCHCONTENT_UPDATES_DISCONNECTED_${contentNameUpper})
|
|
set(disconnectUpdates True)
|
|
else()
|
|
set(disconnectUpdates False)
|
|
endif()
|
|
|
|
if(FETCHCONTENT_QUIET)
|
|
set(quietFlag QUIET)
|
|
else()
|
|
unset(quietFlag)
|
|
endif()
|
|
|
|
__FetchContent_getSavedDetails(${contentName} contentDetails)
|
|
if("${contentDetails}" STREQUAL "")
|
|
message(FATAL_ERROR "No details have been set for content: ${contentName}")
|
|
endif()
|
|
|
|
__FetchContent_directPopulate(
|
|
${contentNameLower}
|
|
${quietFlag}
|
|
UPDATE_DISCONNECTED ${disconnectUpdates}
|
|
SUBBUILD_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-subbuild"
|
|
SOURCE_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-src"
|
|
BINARY_DIR "${FETCHCONTENT_BASE_DIR}/${contentNameLower}-build"
|
|
# Put the saved details last so they can override any of the
|
|
# the options we set above (this can include SOURCE_DIR or
|
|
# BUILD_DIR)
|
|
${contentDetails}
|
|
)
|
|
endif()
|
|
|
|
__FetchContent_setPopulated(
|
|
${contentName}
|
|
${${contentNameLower}_SOURCE_DIR}
|
|
${${contentNameLower}_BINARY_DIR}
|
|
)
|
|
|
|
# Pass variables back to the caller. The variables passed back here
|
|
# must match what FetchContent_GetProperties() sets when it is called
|
|
# with just the content name.
|
|
set(${contentNameLower}_SOURCE_DIR "${${contentNameLower}_SOURCE_DIR}" PARENT_SCOPE)
|
|
set(${contentNameLower}_BINARY_DIR "${${contentNameLower}_BINARY_DIR}" PARENT_SCOPE)
|
|
set(${contentNameLower}_POPULATED True PARENT_SCOPE)
|
|
|
|
endfunction()
|