Re: [PATCH][GOLD] Fix sorting of .init_array and .fini_array input sections.

[Ian Lance Taylor <iant at google dot com>]

"Doug Kwan (éæå)" <dougkwan@google.com> writes:

> 2010-03-01  Doug Kwan  <dougkwan@google.com>
>
>         * layout.cc (Layout::get_output_section): Force section types of
>         .init_array and .fini_array.
>         * output.cc (Output_section::Input_section_sort_entry::has_priority):
>         Fix check of return value of std::string::find.().
>         (Output_section::Input_section_sort_compare::operator()): Remove
>         comment about .init_array.
>         (Output_section::Input_section_sort_init_fini_compare::operator()):
>         New method.
>         (Output_section::sort_attached_input_sections): Handle .init_array
>         and .fini_array specially.
>         * output.h (Output_section::Inut_section_sort_compare): Update
>         comment.
>         (Output_section::Input_section_sort_init_fini_compare): New struct.

> Index: gold/layout.cc
> ===================================================================
> RCS file: /cvs/src/src/gold/layout.cc,v
> retrieving revision 1.166
> diff -u -u -p -r1.166 layout.cc
> --- gold/layout.cc	24 Feb 2010 20:45:12 -0000	1.166
> +++ gold/layout.cc	1 Mar 2010 09:13:39 -0000
> @@ -417,6 +417,14 @@ Layout::get_output_section(const char* n
>    // controlling this.
>    lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
>  
> +  // For section ".init_array" and ".fini_array", force the appropriate
> +  // section types.  Sometimes .init_array.* and .fini_array.* sections have
> +  // type SHT_PROGBITS.
> +  if (strcmp(name, ".init_array") == 0)
> +    type = elfcpp::SHT_INIT_ARRAY;
> +  else if (strcmp(name, ".fini_array") == 0)
> +    type = elfcpp::SHT_FINI_ARRAY;
> +
>    const Key key(name_key, std::make_pair(type, lookup_flags));
>    const std::pair<Key, Output_section*> v(key, NULL);
>    std::pair<Section_name_map::iterator, bool> ins(

I don't think this is the right place for this.  I think you should do
it in the loop over sections in Sized_relobj::do_layout.  Perhaps you
could call a little function to change the type if appropriate.  I
think you should only change the type if the initial type is
SHT_PROGBITS.  You should also force .preinit_array to change from
SHT_PROGBITS to SHT_PREINIT_ARRAY.


> @@ -2819,7 +2853,13 @@ Output_section::sort_attached_input_sect
>      sort_list.push_back(Input_section_sort_entry(*p, i));
>  
>    // Sort the input sections.
> -  std::sort(sort_list.begin(), sort_list.end(), Input_section_sort_compare());
> +  if (strcmp(this->name(), ".init_array") == 0
> +      || strcmp(this->name(), ".fini_array") == 0)
> +    std::sort(sort_list.begin(), sort_list.end(),
> +	      Input_section_sort_init_fini_compare());
> +  else
> +    std::sort(sort_list.begin(), sort_list.end(),
> +	      Input_section_sort_compare());

Now that you have set the type, you should check the type here rather
the name.  You should also check for PREINIT_ARRAY.


This is OK with those changes.

Thanks.

Ian