Re: [PATCH 1/2] gcc/file-prefix-map: Allow remapping of relative paths

[Jeff Law <jeffreyalaw@gmail.com>]

On 8/17/22 06:15, Richard Purdie via Gcc-patches wrote:
> Relative paths currently aren't remapped by -ffile-prefix-map and friends.
> When cross compiling with separate 'source' and 'build' directories, the same
> relative paths between directories may not be available on target as compared
> to build time.
>
> In order to be able to remap these relative build paths to paths that would
> work on target, resolve paths within the file-prefix-map function using
> realpath().

Understood.


>
> This does cause a change of behaviour if users were previously relying upon
> symlinks or absolute paths not being resolved.

I'm not too worried about this scenario.


>
> Use basename to ensure plain filenames don't have paths added.
>
> gcc/ChangeLog:
>
>      * file-prefix-map.cc (remap_filename): Allow remapping of relative paths

Basically OK.  Just formatting nit:



>
> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
> ---
>   gcc/file-prefix-map.cc | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/file-prefix-map.cc b/gcc/file-prefix-map.cc
> index 24733f831d6..50d5d724a8f 100644
> --- a/gcc/file-prefix-map.cc
> +++ b/gcc/file-prefix-map.cc
> @@ -70,19 +70,28 @@ remap_filename (file_prefix_map *maps, const char *filename)
>     file_prefix_map *map;
>     char *s;
>     const char *name;
> +  char *realname;
>     size_t name_len;
>   
> +  if (lbasename (filename) == filename)
> +    return filename;
> +
> +  realname = lrealpath (filename);
> +
>     for (map = maps; map; map = map->next)
> -    if (filename_ncmp (filename, map->old_prefix, map->old_len) == 0)
> +    if (filename_ncmp (realname, map->old_prefix, map->old_len) == 0)
>         break;
> -  if (!map)
> +  if (!map) {
> +    free (realname);
>       return filename;
> -  name = filename + map->old_len;
> +  }


Put the the curley braces go on their own lines, indented two 
positions.  The code inside the curleys is indented two more 
positions.   I fixed that and pushed this change to the trunk.


THanks,

jeff