From 16164a6b00372ebc0360f6aa71337e5613278817 Mon Sep 17 00:00:00 2001 From: Sriraman Tallam Date: Fri, 24 Aug 2012 18:35:35 +0000 Subject: Patch adds support to allow plugins to map selected subset of sections to unique segments. 2012-08-24 Sriraman Tallam * gold.cc (queue_middle_tasks): Call layout again when unique segments for sections is desired. * layout.cc (Layout::Layout): Initialize new members. (Layout::get_output_section_flags): New function. (Layout::choose_output_section): Call get_output_section_flags. (Layout::layout): Make output section for mapping to a unique segment. (Layout::insert_section_segment_map): New function. (Layout::attach_allocated_section_to_segment): Make unique segment for output sections marked so. (Layout::segment_precedes): Check for unique segments when sorting. * layout.h (Layout::Unique_segment_info): New struct. (Layout::Section_segment_map): New typedef. (Layout::insert_section_segment_map): New function. (Layout::get_output_section_flags): New function. (Layout::is_unique_segment_for_sections_specified): New function. (Layout::set_unique_segment_for_sections_specified): New function. (Layout::unique_segment_for_sections_specified_): New member. (Layout::section_segment_map_): New member. * object.cc (Sized_relobj_file::do_layout): Rename is_gc_pass_one to is_pass_one. Rename is_gc_pass_two to is_pass_two. Rename is_gc_or_icf to is_two_pass. Check for which pass based on whether symbols data is present. Make it two pass when unique segments for sections is desired. * output.cc (Output_section::Output_section): Initialize new members. * output.h (Output_section::is_unique_segment): New function. (Output_section::set_is_unique_segment): New function. (Output_section::is_unique_segment_): New member. (Output_section::extra_segment_flags): New function. (Output_section::set_extra_segment_flags): New function. (Output_section::extra_segment_flags_): New member. (Output_section::segment_alignment): New function. (Output_section::set_segment_alignment): New function. (Output_section::segment_alignment_): New member. (Output_segment::Output_segment): Initialize is_unique_segment_. (Output_segment::is_unique_segment): New function. (Output_segment::set_is_unique_segment): New function. (Output_segment::is_unique_segment_): New member. * plugin.cc (allow_unique_segment_for_sections): New function. (unique_segment_for_sections): New function. (Plugin::load): Add new functions to transfer vector. * Makefile.am (plugin_final_layout.readelf.stdout): Add readelf output. * Makefile.in: Regenerate. * testsuite/plugin_final_layout.sh: Check if unique segment functionality works. * testsuite/plugin_section_order.c (onload): Check if new interfaces are available. (allow_unique_segment_for_sections): New global. (unique_segment_for_sections): New global. (claim_file_hook): Call allow_unique_segment_for_sections. (all_symbols_read_hook): Call unique_segment_for_sections. 2012-08-24 Sriraman Tallam * plugin-api.h (ld_plugin_allow_unique_segment_for_sections): New interface. (ld_plugin_unique_segment_for_sections): New interface. (LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. (LDPT_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. (tv_allow_unique_segment_for_sections): New member. (tv_unique_segment_for_sections): New member. --- gold/output.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'gold/output.h') diff --git a/gold/output.h b/gold/output.h index 9b0f87f..25a6b89 100644 --- a/gold/output.h +++ b/gold/output.h @@ -3265,6 +3265,28 @@ class Output_section : public Output_data requires_postprocessing() const { return this->requires_postprocessing_; } + bool + is_unique_segment() const + { return this->is_unique_segment_; } + + void + set_is_unique_segment() + { this->is_unique_segment_ = true; } + + uint64_t extra_segment_flags() const + { return this->extra_segment_flags_; } + + void + set_extra_segment_flags(uint64_t flags) + { this->extra_segment_flags_ = flags; } + + uint64_t segment_alignment() const + { return this->segment_alignment_; } + + void + set_segment_alignment(uint64_t align) + { this->segment_alignment_ = align; } + // If a section requires postprocessing, return the buffer to use. unsigned char* postprocessing_buffer() const @@ -4216,9 +4238,17 @@ class Output_section : public Output_data bool has_fixed_layout_ : 1; // True if we can add patch space to this section. bool is_patch_space_allowed_ : 1; + // True if this output section goes into a unique segment. + bool is_unique_segment_ : 1; // For SHT_TLS sections, the offset of this section relative to the base // of the TLS segment. uint64_t tls_offset_; + // Additional segment flags, specified via linker plugin, when mapping some + // input sections to unique segments. + uint64_t extra_segment_flags_; + // Segment alignment specified via linker plugin, when mapping some + // input sections to unique segments. + uint64_t segment_alignment_; // Saved checkpoint. Checkpoint_output_section* checkpoint_; // Fast lookup maps for merged and relaxed input sections. @@ -4294,6 +4324,16 @@ class Output_segment set_is_large_data_segment() { this->is_large_data_segment_ = true; } + bool + is_unique_segment() const + { return this->is_unique_segment_; } + + // Mark segment as unique, happens when linker plugins request that + // certain input sections be mapped to unique segments. + void + set_is_unique_segment() + { this->is_unique_segment_ = true; } + // Return the maximum alignment of the Output_data. uint64_t maximum_alignment(); @@ -4504,6 +4544,8 @@ class Output_segment bool are_addresses_set_ : 1; // Whether this segment holds large data sections. bool is_large_data_segment_ : 1; + // Whether this was marked as a unique segment via a linker plugin. + bool is_unique_segment_ : 1; }; // This class represents the output file. -- cgit v1.1