diff options
Diffstat (limited to 'cmake')
-rw-r--r-- | cmake/Modules/FindPrefixFromConfig.cmake | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/cmake/Modules/FindPrefixFromConfig.cmake b/cmake/Modules/FindPrefixFromConfig.cmake new file mode 100644 index 000000000000..aa9fb0d03413 --- /dev/null +++ b/cmake/Modules/FindPrefixFromConfig.cmake @@ -0,0 +1,41 @@ +# Find the prefix from the `*Config.cmake` file being generated. +# +# When generating an installed `*Config.cmake` file, we often want to be able +# to refer to the ancestor directory which contains all the installed files. +# +# We want to do this without baking in an absolute path when the config file is +# generated, in order to allow for a "relocatable" binary distribution that +# doesn't need to know what path it ends up being installed at when it is +# built. +# +# The solution that we know the relative path that the config file will be at +# within that prefix, like `"${prefix_var}/lib/cmake/${project}"`, so we count +# the number of components in that path to figure out how many parent dirs we +# need to traverse from the location of the config file to get to the prefix +# dir. +# +# out_var: +# variable to set the "return value" of the function, which is the code to +# include in the config file under construction. +# +# prefix_var: +# Name of the variable to define in the returned code (not directory for the +# faller!) that will contain the prefix path. +# +# path_to_leave: +# Path from the prefix to the config file, a relative path which we wish to +# go up and out from to find the prefix directory. +function(find_prefix_from_config out_var prefix_var path_to_leave) + set(config_code + "# Compute the installation prefix from this LLVMConfig.cmake file location." + "get_filename_component(${prefix_var} \"\${CMAKE_CURRENT_LIST_FILE}\" PATH)") + # Construct the proper number of get_filename_component(... PATH) + # calls to compute the installation prefix. + string(REGEX REPLACE "/" ";" _count "${path_to_leave}") + foreach(p ${_count}) + list(APPEND config_code + "get_filename_component(${prefix_var} \"\${${prefix_var}}\" PATH)") + endforeach(p) + string(REPLACE ";" "\n" config_code "${config_code}") + set("${out_var}" "${config_code}" PARENT_SCOPE) +endfunction() |