CheckPIESupported

在 3.14 版被加入.

This module provides the check_pie_supported() function to check whether the linker supports Position Independent Code (PIE) or No Position Independent Code (NO_PIE) for executables.

When setting the POSITION_INDEPENDENT_CODE target property, PIC-related compile and link options are added when building library objects, and PIE-related compile options are added when building objects of executable targets, regardless of this module. Use this module to ensure that the POSITION_INDEPENDENT_CODE target property for executables is also honored at link time.

check_pie_supported

check_pie_supported([OUTPUT_VARIABLE <output>]
                    [LANGUAGES <lang>...])

Options are:

OUTPUT_VARIABLE <output>

Set <output> variable with details about any error. If the check is bypassed because it uses cached results from a previous call, the output will be empty even if errors were present in the previous call.

LANGUAGES <lang>...

Check the linkers used for each of the specified languages. If this option is not provided, the command checks all enabled languages.

C, CXX, Fortran are supported.

在 3.23 版被加入: OBJC, OBJCXX, CUDA, and HIP are supported.

備註

To use check_pie_supported(), policy CMP0083 must be set to NEW; otherwise, a fatal error will occur.

變數

For each language checked, the check_pie_supported() function defines two boolean cache variables:

CMAKE_<lang>_LINK_PIE_SUPPORTED

Set to true if PIE is supported by the linker and false otherwise.

CMAKE_<lang>_LINK_NO_PIE_SUPPORTED

Set to true if NO_PIE is supported by the linker and false otherwise.

範例

To enable PIE on an executable target at link time as well, include this module and call check_pie_supported() before setting the POSITION_INDEPENDENT_CODE target property. This will determine whether the linker for each checked language supports PIE-related link options. For example:

add_executable(foo ...)

include(CheckPIESupported)
check_pie_supported()
set_property(TARGET foo PROPERTY POSITION_INDEPENDENT_CODE TRUE)

Since not all linkers require or support PIE-related link options (for example, MSVC), retrieving any error messages might be useful for logging purposes:

add_executable(foo ...)

include(CheckPIESupported)
check_pie_supported(OUTPUT_VARIABLE output LANGUAGES C)
set_property(TARGET foo PROPERTY POSITION_INDEPENDENT_CODE TRUE)
if(NOT CMAKE_C_LINK_PIE_SUPPORTED)
  message(WARNING "PIE is not supported at link time:\n${output}"
                  "PIE link options will not be passed to linker.")
endif()

Setting the POSITION_INDEPENDENT_CODE target property on an executable without this module will set PIE-related compile options but not PIE-related link options, which might not be sufficient in certain cases:

add_executable(foo ...)
set_property(TARGET foo PROPERTY POSITION_INDEPENDENT_CODE TRUE)