gbe_fork/cmake/share/cmake-3.27/Help/policy/CMP0083.rst

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2023-12-17 02:34:09 +08:00
CMP0083
-------
.. versionadded:: 3.14
To control generation of Position Independent Executable (``PIE``) or not, some
flags are required at link time.
CMake 3.13 and lower did not add these link flags when
:prop_tgt:`POSITION_INDEPENDENT_CODE` is set.
The ``OLD`` behavior for this policy is to not manage ``PIE`` link flags. The
``NEW`` behavior is to add link flags if :prop_tgt:`POSITION_INDEPENDENT_CODE`
is set:
* Set to ``TRUE``: flags to produce a position independent executable are
passed to the linker step. For example ``-pie`` for ``GCC``.
* Set to ``FALSE``: flags not to produce a position independent executable are
passed to the linker step. For example ``-no-pie`` for ``GCC``.
* Not set: no flags are passed to the linker step.
Since a given linker may not support ``PIE`` flags in all environments in
which it is used, it is the project's responsibility to use the
:module:`CheckPIESupported` module to check for support to ensure that the
:prop_tgt:`POSITION_INDEPENDENT_CODE` target property for executables will be
honored at link time.
This policy was introduced in CMake version 3.14. Use the
:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
Unlike most policies, CMake version |release| does not warn when this policy is
not set and simply uses ``OLD`` behavior.
.. Note::
Android platform has a special handling of ``PIE`` so it is not required
to use the :module:`CheckPIESupported` module to ensure flags are passed to
the linker.
.. include:: DEPRECATED.txt
Examples
^^^^^^^^
Behave like CMake 3.13 and do not apply any ``PIE`` flags at link stage.
.. code-block:: cmake
cmake_minimum_required(VERSION 3.13)
project(foo)
# ...
add_executable(foo ...)
set_property(TARGET foo PROPERTY POSITION_INDEPENDENT_CODE TRUE)
Use the :module:`CheckPIESupported` module to detect whether ``PIE`` is
supported by the current linker and environment. Apply ``PIE`` flags only
if the linker supports them.
.. code-block:: cmake
cmake_minimum_required(VERSION 3.14) # CMP0083 NEW
project(foo)
include(CheckPIESupported)
check_pie_supported()
# ...
add_executable(foo ...)
set_property(TARGET foo PROPERTY POSITION_INDEPENDENT_CODE TRUE)