From cf48022dc52fe5dd8161d591e4fb8b1f076ce52e Mon Sep 17 00:00:00 2001 From: scivision Date: Wed, 8 Mar 2023 00:23:49 -0500 Subject: Help:Check*: include CMAKE_REQUIRED_* vars to dedupe CMAKE_REQUIRED_FLAGS now notes that space-delimited string, not ;-list is required, which could be surprising compared to similar options that do use ;-list --- Modules/CheckOBJCCompilerFlag.cmake | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) (limited to 'Modules/CheckOBJCCompilerFlag.cmake') diff --git a/Modules/CheckOBJCCompilerFlag.cmake b/Modules/CheckOBJCCompilerFlag.cmake index d8d874175f..b0b7a43481 100644 --- a/Modules/CheckOBJCCompilerFlag.cmake +++ b/Modules/CheckOBJCCompilerFlag.cmake @@ -13,25 +13,37 @@ Check whether the Objective-C compiler supports a given flag. .. code-block:: cmake - check_objc_compiler_flag( ) + check_objc_compiler_flag( ) Check that the ```` is accepted by the compiler without a diagnostic. Stores the result in an internal cache entry - named ````. - -This command temporarily sets the ``CMAKE_REQUIRED_DEFINITIONS`` variable -and calls the ``check_objc_source_compiles`` macro from the -:module:`CheckOBJCSourceCompiles` module. See documentation of that -module for a listing of variables that can otherwise modify the build. + named ````. A positive result from this check indicates only that the compiler did not issue a diagnostic message when given the flag. Whether the flag has any effect or even a specific one is beyond the scope of this module. -.. note:: - Since the :command:`try_compile` command forwards flags from variables - like :variable:`CMAKE_OBJC_FLAGS _FLAGS>`, unknown flags - in such variables may cause a false negative for this check. +The check is only performed once, with the result cached in the variable named +by ````. Every subsequent CMake run will re-use this cached value +rather than performing the check again, even if the ```` changes. In +order to force the check to be re-evaluated, the variable named by +```` must be manually removed from the cache. + +The compile and link commands can be influenced by setting any of the +following variables prior to calling ``check_objc_compiler_flag()`` + +.. include:: /module/CMAKE_REQUIRED_FLAGS.txt + +.. include:: /module/CMAKE_REQUIRED_DEFINITIONS.txt + +.. include:: /module/CMAKE_REQUIRED_INCLUDES.txt + +.. include:: /module/CMAKE_REQUIRED_LINK_OPTIONS.txt + +.. include:: /module/CMAKE_REQUIRED_LIBRARIES.txt + +.. include:: /module/CMAKE_REQUIRED_QUIET.txt + #]=======================================================================] include_guard(GLOBAL) -- cgit v1.2.1