[GOLD][PATCH]Handle script sections in Output_section::get_input_section.

[=?big5?b?RG91ZyBLd2FuICjD9q62vHcp?= <dougkwan at google dot com>]

This patch add support for exporting and re-importing merge sections
Output_section class, as discussed earlier.  All merged input sections
of the same properties are exported together in a merge object, which
is treated as the first merge input section in a sections script.  The
maps for looking up merge and relaxed sections in Output_sections are
refactored into a separate class Output_section_lookup_maps.  The
patch also fixes two issues in arm.cc.

This was tested on x86_64 and ARM, both natively.

-Doug



2010-05-21  Doug Kwan  <dougkwan@google.com>

        * arm.cc (Arm_input_section::do_output_offset): Add a cast to
        avoid a compilation error.
        (Target_arm::apply_cortex_a8_workaround): Rewrite a conditional branch
        with a direct branch, not a conditional branch, to a stub.
        * merge.cc (Output_merge_base::record_input_section): New method
        defintion.
        (Output_merge_data::do_add_input_section): Record input section if
        keeps-input-sections flag is set.
        (Output_merge_string::do_add_input_section): Ditto.
        * merge.h (Output_merge_base::Output_merge_base): Initialize new data
        members KEEPS_INPUT_SECTIONS_, FIRST_RELOBJ_, FIRST_SHNDX_ and
        INPUT_SECTIONS_.
        (Output_merge_base::keeps_input_sections,
        Output_merge_base::set_keeps_input_sections,
        Output_merge_base::first_relobj, Output_merge_base::first_shndx): New
        method definitions.
        (Output_merge_base::Input_sections): New type declaration.
        (Output_merge_base::input_sections_begin,
        Output_merge_base::input_sections_end,
        Output_merge_base::do_set_keeps_input_sections): New method definitions.
        (Output_merge_base::bool keeps_input_sections_,
        Output_merge_base::first_relobj_, Output_merge_base::first_shndx_,
        Output_merge_base::input_sections_): New data members.
        (Output_merge_data::do_set_keeps_input_sections): New method
        defintion.
        (Output_merge_string::do_set_keeps_input_sections): Ditto.
        * output.cc (Output_section::Input_section::relobj): Move method
        defintion from class declaration to here and handle merge sections.
        (Output_section::Input_section::shndx): Ditto.
        (Output_section::Output_section): Remove initializations of removed
        data members and initialize new data member LOOKUP_MAPS_.
        (Output_section::add_input_section): Set keeps-input-sections flag
        for a newly created merge output section as appropriate.  Adjust code
        to use Output_section_lookup_maps class.
        (Output_section::add_relaxed_input_section): Adjst code for lookup
        maps code refactoring.
        (Output_section::add_merge_input_section): Add a new parameter
        KEEPS_INPUT_SECTION.  Adjust code to use Output_section_lookup_maps
        class.  If adding input section to a newly created merge output
        section fails, remove the new merge section.
        (Output_section::convert_input_sections_in_list_to_relaxed_input_sections):
        Adjust code for use of the Output_section_lookup_maps class.
        (Output_section::find_merge_section): Ditto.
        (Output_section::build_lookup_maps): New method defintion.
        (Output_section::find_relaxed_input_section): Adjust code to use
        Output_section_lookup_maps class.
        (Output_section::get_input_sections): Export merge sections.  Adjust
        code to use Output_section_lookup_maps class.
        (Output_section:::add_script_input_section): Adjust code to use
        Output_section_lookup_maps class.  Update lookup maps for merge
        sections also.
        (Output_section::discard_states): Use Output_section_lookup_maps.
        (Output_section::restore_states): Same.
        * output.h (Merge_section_properties): Move class defintion out of
        Output_section.
        (Output_section_lookup_maps): New class.
        (Output_section::Input_section::is_merge_section): New method
        defintion.
        (Output_section::Input_section::relobj): Move defintion out of class
        defintion.  Declare method only.
        (Output_section::Input_section::shndx): Ditto.
        (Output_section::Input_section::output_merge_base): New method
defintion.
        (Output_section::Input_section::u2_.pomb): New union field.
        (Output_section::Merge_section_by_properties_map,
        Output_section::Output_section_data_by_input_section_map,
        Output_section::Ouptut_relaxed_input_section_by_input_section_map):
        Remove types.
        (Output_section::add_merge_input_section): Add new parameter
        KEEPS_INPUT_SECTIONS.
        (Output_section::build_lookup_maps): New method declaration.
        (Output_section::merge_section_map_,
        Output_section::merge_section_by_properties_map_,
        Output_section::relaxed_input_section_map_,
        Output_section::is_relaxed_input_section_map_valid_): Remove data
        members.
        (Output_section::lookup_maps_): New data member.

Attachment: patch-merge-section.txt
Description: Text document