Display cmake variables code#

The child project’s option while still allowing the user to edit the However, it may be necessary to hard-code the value for Normally, the child would then use the same value that the The parent gets the first chance to add a user-editable option to theĬache. Now, if the parent and theĬhild project provide the same option (for example a compiler option), Its own CMakeLists.txt, which is included from the parentĬMakeLists.txt using add_subdirectory().

One example (used by someĪ project has a subproject in its source tree. Same name, as this interaction can be hard to follow. Normally projects should avoid using normal and cache variables of the If ‘FOO’ is not in the cache, then it is added to theįinally, whenever a cache variable is added or modified by a command,ĬMake also removes the normal variable of the same name from theĬurrent scope so that an immediately following evaluation of it will If ‘FOO’ is in theĬache then nothing happens to either the normal variable or the cache Ignoring any normal variable of the same name.

Display cmake variables code#

The code ‘set(FOO “x” CACHE …)’ checks for ‘FOO’ in the cache, Touch the cache, but it will hide any existing cache value ‘FOO’. The code ‘set(FOO “x”)’ sets the normal variable ‘FOO’. Variable exists then it falls back to the cache variable ‘FOO’. Variable ‘FOO’ in scope and uses it if set. When $ is evaluated, CMake first looks for a normal Cache variables are stored in the CMake cache file, andīoth types can exist at the same time with the same name but different INTERNAL) are mostly intended for configuration settings where theįirst CMake run determines a suitable default value, which the userĬan then override, by editing the cache with tools such as ccmake orĬmake-gui. Script (just like variables in most programming languages) they are Normal variables are meant for the internal use of the In CMake there are two types of variables: normal variables and cache In which case the environment variable will be set. If is not specified then the variable is removed instead of PARENT_SCOPE cannot be combined with CACHE. This command will set the value of a variable into the parentĭirectory or calling function (whichever is applicable to the case at Each new directory or function creates a new If PARENT_SCOPE is present, the variable will be set in the scopeĪbove the current scope. Normally be avoided, as it will remove any changes to the cache Is set, even if the variable is already in the cache. If FORCE is specified, the value of the cache variable Normally, set(…CACHE…) creates cache variables, but does not Intended for values that should be persisted in the cache, but which Will not be shown to the user in tools like cmake-gui. If is INTERNAL, the cache variable is marked as internal, and INTERNAL = No GUI entry ( used for persistent variables ).