[cmake-developers] [PATCH 1/6] Use find on UNIX for fast executable lookup

[Rolf Eike Beer]

Am 04.09.2014 15:11, schrieb Adam Strzelecki:
> It makes whole executable process quicker on UNIX, especially for large 
> bundles
> containing many files, since using find narrows results to only files 
> having
> executable flags then all further tests follow.
> ---
>  Modules/BundleUtilities.cmake | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/Modules/BundleUtilities.cmake 
> b/Modules/BundleUtilities.cmake
> index 0046c97..7e2b173 100644
> --- a/Modules/BundleUtilities.cmake
> +++ b/Modules/BundleUtilities.cmake
> @@ -378,7 +378,24 @@ endfunction()
>  function(get_bundle_all_executables bundle exes_var)
>    set(exes "")
> 
> -  file(GLOB_RECURSE file_list "${bundle}/*")
> +  if(UNIX)
> +    find_program(find_cmd "find")
> +    mark_as_advanced(find_cmd)
> +  endif()
> +
> +  # find command is much quicker than checking every file one by one 
> on Unix
> +  # which can take long time for large bundles, and since anyway we 
> expect
> +  # executable to have execute flag set we can narrow the list much 
> quicker.
> +  if(find_cmd)
> +    execute_process(COMMAND "${find_cmd}" "${bundle}" -type f -perm 
> +0111
> +      OUTPUT_VARIABLE file_list
> +      OUTPUT_STRIP_TRAILING_WHITESPACE
> +      )
> +    string(REPLACE "\n" ";" file_list ${file_list})
> +  else()
> +    file(GLOB_RECURSE file_list "${bundle}/*")
> +  endif()
> +
>    foreach(f ${file_list})
>      is_file_executable("${f}" is_executable)
>      if(is_executable)
> --

I wonder if the "right" solution would instead be to add some additional 
flags to GLOB/GLOB_RECURSE where one could e.g. specify that the file is 
executable, or is a directory. Looking at GetPrerequisites.cmake, 
FindDoxygen.cmake, and CMakeDetermineCompilerId.cmake this could be a 
good idea for other places, too.

Eike