[PATCH] GOLD/DWP: avoid segmentation fault for binaries without debug fission

[Sriraman Tallam]

On Mon, May 16, 2016 at 4:56 PM, Yunlian Jiang <yunlian@google.com> wrote:
> If run dwp command on a binary built without debug fission, it will
> cause segmentation
> fault. This patch fixes that by exit early if no DWO files information
> found inside the
> input binary.
>
>     gold/
>     * dwp.cc: (main): exit early when no DWO files information found
> in the input binary.
>
> diff --git a/gold/dwp.cc b/gold/dwp.cc
> index d8c39c6..c26f969 100644
> --- a/gold/dwp.cc
> +++ b/gold/dwp.cc
> @@ -2436,6 +2436,11 @@ main(int argc, char** argv)
>        return ok ? EXIT_SUCCESS : EXIT_FAILURE;
>      }
>
> +  // If there is no DWO files information found in the input binary,
> +  // return early to avoid segmentation fault.

Change the comment to maybe "If there are no DWO files, there is
nothing to do."

> +  if (files.size() == 0)
> +    return EXIT_SUCCESS;
> +

This looks fine to me but I do not have permissions to approve.

Thanks
Sri

>    // Process each file, adding its contents to the output file.
>    Dwp_output_file output_file(output_filename.c_str());
>    for (File_list::const_iterator f = files.begin(); f != files.end(); ++f)