--- /dev/null
+// layout.h -- lay out output file sections for gold -*- C++ -*-
+
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#ifndef GOLD_LAYOUT_H
+#define GOLD_LAYOUT_H
+
+#include <cstring>
+#include <list>
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "script.h"
+#include "workqueue.h"
+#include "object.h"
+#include "dynobj.h"
+#include "stringpool.h"
+
+namespace gold
+{
+
+class General_options;
+class Incremental_inputs;
+class Input_objects;
+class Mapfile;
+class Symbol_table;
+class Output_section_data;
+class Output_section;
+class Output_section_headers;
+class Output_segment_headers;
+class Output_file_header;
+class Output_segment;
+class Output_data;
+class Output_data_dynamic;
+class Output_symtab_xindex;
+class Output_reduced_debug_abbrev_section;
+class Output_reduced_debug_info_section;
+class Eh_frame;
+class Target;
+
+// This task function handles mapping the input sections to output
+// sections and laying them out in memory.
+
+class Layout_task_runner : public Task_function_runner
+{
+ public:
+ // OPTIONS is the command line options, INPUT_OBJECTS is the list of
+ // input objects, SYMTAB is the symbol table, LAYOUT is the layout
+ // object.
+ Layout_task_runner(const General_options& options,
+ const Input_objects* input_objects,
+ Symbol_table* symtab,
+ Target* target,
+ Layout* layout,
+ Mapfile* mapfile)
+ : options_(options), input_objects_(input_objects), symtab_(symtab),
+ target_(target), layout_(layout), mapfile_(mapfile)
+ { }
+
+ // Run the operation.
+ void
+ run(Workqueue*, const Task*);
+
+ private:
+ Layout_task_runner(const Layout_task_runner&);
+ Layout_task_runner& operator=(const Layout_task_runner&);
+
+ const General_options& options_;
+ const Input_objects* input_objects_;
+ Symbol_table* symtab_;
+ Target* target_;
+ Layout* layout_;
+ Mapfile* mapfile_;
+};
+
+// This class holds information about the comdat group or
+// .gnu.linkonce section that will be kept for a given signature.
+
+class Kept_section
+{
+ private:
+ // For a comdat group, we build a mapping from the name of each
+ // section in the group to the section index and the size in object.
+ // When we discard a group in some other object file, we use this
+ // map to figure out which kept section the discarded section is
+ // associated with. We then use that mapping when processing relocs
+ // against discarded sections.
+ struct Comdat_section_info
+ {
+ // The section index.
+ unsigned int shndx;
+ // The section size.
+ uint64_t size;
+
+ Comdat_section_info(unsigned int a_shndx, uint64_t a_size)
+ : shndx(a_shndx), size(a_size)
+ { }
+ };
+
+ // Most comdat groups have only one or two sections, so we use a
+ // std::map rather than an Unordered_map to optimize for that case
+ // without paying too heavily for groups with more sections.
+ typedef std::map<std::string, Comdat_section_info> Comdat_group;
+
+ public:
+ Kept_section()
+ : object_(NULL), shndx_(0), is_comdat_(false), is_group_name_(false)
+ { this->u_.linkonce_size = 0; }
+
+ // We need to support copies for the signature map in the Layout
+ // object, but we should never copy an object after it has been
+ // marked as a comdat section.
+ Kept_section(const Kept_section& k)
+ : object_(k.object_), shndx_(k.shndx_), is_comdat_(false),
+ is_group_name_(k.is_group_name_)
+ {
+ gold_assert(!k.is_comdat_);
+ this->u_.linkonce_size = 0;
+ }
+
+ ~Kept_section()
+ {
+ if (this->is_comdat_)
+ delete this->u_.group_sections;
+ }
+
+ // The object where this section lives.
+ Relobj*
+ object() const
+ { return this->object_; }
+
+ // Set the object.
+ void
+ set_object(Relobj* object)
+ {
+ gold_assert(this->object_ == NULL);
+ this->object_ = object;
+ }
+
+ // The section index.
+ unsigned int
+ shndx() const
+ { return this->shndx_; }
+
+ // Set the section index.
+ void
+ set_shndx(unsigned int shndx)
+ {
+ gold_assert(this->shndx_ == 0);
+ this->shndx_ = shndx;
+ }
+
+ // Whether this is a comdat group.
+ bool
+ is_comdat() const
+ { return this->is_comdat_; }
+
+ // Set that this is a comdat group.
+ void
+ set_is_comdat()
+ {
+ gold_assert(!this->is_comdat_);
+ this->is_comdat_ = true;
+ this->u_.group_sections = new Comdat_group();
+ }
+
+ // Whether this is associated with the name of a group or section
+ // rather than the symbol name derived from a linkonce section.
+ bool
+ is_group_name() const
+ { return this->is_group_name_; }
+
+ // Note that this represents a comdat group rather than a single
+ // linkonce section.
+ void
+ set_is_group_name()
+ { this->is_group_name_ = true; }
+
+ // Add a section to the group list.
+ void
+ add_comdat_section(const std::string& name, unsigned int shndx,
+ uint64_t size)
+ {
+ gold_assert(this->is_comdat_);
+ Comdat_section_info sinfo(shndx, size);
+ this->u_.group_sections->insert(std::make_pair(name, sinfo));
+ }
+
+ // Look for a section name in the group list, and return whether it
+ // was found. If found, returns the section index and size.
+ bool
+ find_comdat_section(const std::string& name, unsigned int *pshndx,
+ uint64_t *psize) const
+ {
+ gold_assert(this->is_comdat_);
+ Comdat_group::const_iterator p = this->u_.group_sections->find(name);
+ if (p == this->u_.group_sections->end())
+ return false;
+ *pshndx = p->second.shndx;
+ *psize = p->second.size;
+ return true;
+ }
+
+ // If there is only one section in the group list, return true, and
+ // return the section index and size.
+ bool
+ find_single_comdat_section(unsigned int *pshndx, uint64_t *psize) const
+ {
+ gold_assert(this->is_comdat_);
+ if (this->u_.group_sections->size() != 1)
+ return false;
+ Comdat_group::const_iterator p = this->u_.group_sections->begin();
+ *pshndx = p->second.shndx;
+ *psize = p->second.size;
+ return true;
+ }
+
+ // Return the size of a linkonce section.
+ uint64_t
+ linkonce_size() const
+ {
+ gold_assert(!this->is_comdat_);
+ return this->u_.linkonce_size;
+ }
+
+ // Set the size of a linkonce section.
+ void
+ set_linkonce_size(uint64_t size)
+ {
+ gold_assert(!this->is_comdat_);
+ this->u_.linkonce_size = size;
+ }
+
+ private:
+ // No assignment.
+ Kept_section& operator=(const Kept_section&);
+
+ // The object containing the comdat group or .gnu.linkonce section.
+ Relobj* object_;
+ // Index of the group section for comdats and the section itself for
+ // .gnu.linkonce.
+ unsigned int shndx_;
+ // True if this is for a comdat group rather than a .gnu.linkonce
+ // section.
+ bool is_comdat_;
+ // The Kept_sections are values of a mapping, that maps names to
+ // them. This field is true if this struct is associated with the
+ // name of a comdat or .gnu.linkonce, false if it is associated with
+ // the name of a symbol obtained from the .gnu.linkonce.* name
+ // through some heuristics.
+ bool is_group_name_;
+ union
+ {
+ // If the is_comdat_ field is true, this holds a map from names of
+ // the sections in the group to section indexes in object_ and to
+ // section sizes.
+ Comdat_group* group_sections;
+ // If the is_comdat_ field is false, this holds the size of the
+ // single section.
+ uint64_t linkonce_size;
+ } u_;
+};
+
+// This class handles the details of laying out input sections.
+
+class Layout
+{
+ public:
+ Layout(int number_of_input_files, Script_options*);
+
+ ~Layout()
+ {
+ delete this->relaxation_debug_check_;
+ delete this->segment_states_;
+ }
+
+ // Given an input section SHNDX, named NAME, with data in SHDR, from
+ // the object file OBJECT, return the output section where this
+ // input section should go. RELOC_SHNDX is the index of a
+ // relocation section which applies to this section, or 0 if none,
+ // or -1U if more than one. RELOC_TYPE is the type of the
+ // relocation section if there is one. Set *OFFSET to the offset
+ // within the output section.
+ template<int size, bool big_endian>
+ Output_section*
+ layout(Sized_relobj<size, big_endian> *object, unsigned int shndx,
+ const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
+ unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset);
+
+ // Layout an input reloc section when doing a relocatable link. The
+ // section is RELOC_SHNDX in OBJECT, with data in SHDR.
+ // DATA_SECTION is the reloc section to which it refers. RR is the
+ // relocatable information.
+ template<int size, bool big_endian>
+ Output_section*
+ layout_reloc(Sized_relobj<size, big_endian>* object,
+ unsigned int reloc_shndx,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr);
+
+ // Layout a group section when doing a relocatable link.
+ template<int size, bool big_endian>
+ void
+ layout_group(Symbol_table* symtab,
+ Sized_relobj<size, big_endian>* object,
+ unsigned int group_shndx,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
+
+ // Like layout, only for exception frame sections. OBJECT is an
+ // object file. SYMBOLS is the contents of the symbol table
+ // section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of
+ // the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a
+ // .eh_frame section in OBJECT. SHDR is the section header.
+ // RELOC_SHNDX is the index of a relocation section which applies to
+ // this section, or 0 if none, or -1U if more than one. RELOC_TYPE
+ // is the type of the relocation section if there is one. This
+ // returns the output section, and sets *OFFSET to the offset.
+ template<int size, bool big_endian>
+ Output_section*
+ layout_eh_frame(Sized_relobj<size, big_endian>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ unsigned int reloc_shndx, unsigned int reloc_type,
+ off_t* offset);
+
+ // Handle a GNU stack note. This is called once per input object
+ // file. SEEN_GNU_STACK is true if the object file has a
+ // .note.GNU-stack section. GNU_STACK_FLAGS is the section flags
+ // from that section if there was one.
+ void
+ layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags);
+
+ // Add an Output_section_data to the layout. This is used for
+ // special sections like the GOT section.
+ Output_section*
+ add_output_section_data(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags,
+ Output_section_data*);
+
+ // Create dynamic sections if necessary.
+ void
+ create_initial_dynamic_sections(Symbol_table*);
+
+ // Define __start and __stop symbols for output sections.
+ void
+ define_section_symbols(Symbol_table*);
+
+ // Create automatic note sections.
+ void
+ create_notes();
+
+ // Create sections for linker scripts.
+ void
+ create_script_sections()
+ { this->script_options_->create_script_sections(this); }
+
+ // Define symbols from any linker script.
+ void
+ define_script_symbols(Symbol_table* symtab)
+ { this->script_options_->add_symbols_to_table(symtab); }
+
+ // Define symbols for group signatures.
+ void
+ define_group_signatures(Symbol_table*);
+
+ // Return the Stringpool used for symbol names.
+ const Stringpool*
+ sympool() const
+ { return &this->sympool_; }
+
+ // Return the Stringpool used for dynamic symbol names and dynamic
+ // tags.
+ const Stringpool*
+ dynpool() const
+ { return &this->dynpool_; }
+
+ // Return the symtab_xindex section used to hold large section
+ // indexes for the normal symbol table.
+ Output_symtab_xindex*
+ symtab_xindex() const
+ { return this->symtab_xindex_; }
+
+ // Return the dynsym_xindex section used to hold large section
+ // indexes for the dynamic symbol table.
+ Output_symtab_xindex*
+ dynsym_xindex() const
+ { return this->dynsym_xindex_; }
+
+ // Return whether a section is a .gnu.linkonce section, given the
+ // section name.
+ static inline bool
+ is_linkonce(const char* name)
+ { return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; }
+
+ // Return true if a section is a debugging section.
+ static inline bool
+ is_debug_info_section(const char* name)
+ {
+ // Debugging sections can only be recognized by name.
+ return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0
+ || strncmp(name, ".gnu.linkonce.wi.",
+ sizeof(".gnu.linkonce.wi.") - 1) == 0
+ || strncmp(name, ".line", sizeof(".line") - 1) == 0
+ || strncmp(name, ".stab", sizeof(".stab") - 1) == 0);
+ }
+
+ // Check if a comdat group or .gnu.linkonce section with the given
+ // NAME is selected for the link. If there is already a section,
+ // *KEPT_SECTION is set to point to the signature and the function
+ // returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and
+ // IS_GROUP_NAME are recorded for this NAME in the layout object,
+ // *KEPT_SECTION is set to the internal copy and the function return
+ // false.
+ bool
+ find_or_add_kept_section(const std::string& name, Relobj* object,
+ unsigned int shndx, bool is_comdat,
+ bool is_group_name, Kept_section** kept_section);
+
+ // Finalize the layout after all the input sections have been added.
+ off_t
+ finalize(const Input_objects*, Symbol_table*, Target*, const Task*);
+
+ // Return whether any sections require postprocessing.
+ bool
+ any_postprocessing_sections() const
+ { return this->any_postprocessing_sections_; }
+
+ // Return the size of the output file.
+ off_t
+ output_file_size() const
+ { return this->output_file_size_; }
+
+ // Return the TLS segment. This will return NULL if there isn't
+ // one.
+ Output_segment*
+ tls_segment() const
+ { return this->tls_segment_; }
+
+ // Return the normal symbol table.
+ Output_section*
+ symtab_section() const
+ {
+ gold_assert(this->symtab_section_ != NULL);
+ return this->symtab_section_;
+ }
+
+ // Return the dynamic symbol table.
+ Output_section*
+ dynsym_section() const
+ {
+ gold_assert(this->dynsym_section_ != NULL);
+ return this->dynsym_section_;
+ }
+
+ // Return the dynamic tags.
+ Output_data_dynamic*
+ dynamic_data() const
+ { return this->dynamic_data_; }
+
+ // Write out the output sections.
+ void
+ write_output_sections(Output_file* of) const;
+
+ // Write out data not associated with an input file or the symbol
+ // table.
+ void
+ write_data(const Symbol_table*, Output_file*) const;
+
+ // Write out output sections which can not be written until all the
+ // input sections are complete.
+ void
+ write_sections_after_input_sections(Output_file* of);
+
+ // Return an output section named NAME, or NULL if there is none.
+ Output_section*
+ find_output_section(const char* name) const;
+
+ // Return an output segment of type TYPE, with segment flags SET set
+ // and segment flags CLEAR clear. Return NULL if there is none.
+ Output_segment*
+ find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
+ elfcpp::Elf_Word clear) const;
+
+ // Return the number of segments we expect to produce.
+ size_t
+ expected_segment_count() const;
+
+ // Set a flag to indicate that an object file uses the static TLS model.
+ void
+ set_has_static_tls()
+ { this->has_static_tls_ = true; }
+
+ // Return true if any object file uses the static TLS model.
+ bool
+ has_static_tls() const
+ { return this->has_static_tls_; }
+
+ // Return the options which may be set by a linker script.
+ Script_options*
+ script_options()
+ { return this->script_options_; }
+
+ const Script_options*
+ script_options() const
+ { return this->script_options_; }
+
+ // Return the object managing inputs in incremental build. NULL in
+ // non-incremental builds.
+ Incremental_inputs*
+ incremental_inputs()
+ { return this->incremental_inputs_; }
+
+ // Compute and write out the build ID if needed.
+ void
+ write_build_id(Output_file*) const;
+
+ // Rewrite output file in binary format.
+ void
+ write_binary(Output_file* in) const;
+
+ // Print output sections to the map file.
+ void
+ print_to_mapfile(Mapfile*) const;
+
+ // Dump statistical information to stderr.
+ void
+ print_stats() const;
+
+ // A list of segments.
+
+ typedef std::vector<Output_segment*> Segment_list;
+
+ // A list of sections.
+
+ typedef std::vector<Output_section*> Section_list;
+
+ // The list of information to write out which is not attached to
+ // either a section or a segment.
+ typedef std::vector<Output_data*> Data_list;
+
+ // Store the allocated sections into the section list. This is used
+ // by the linker script code.
+ void
+ get_allocated_sections(Section_list*) const;
+
+ // Make a section for a linker script to hold data.
+ Output_section*
+ make_output_section_for_script(const char* name);
+
+ // Make a segment. This is used by the linker script code.
+ Output_segment*
+ make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags);
+
+ // Return the number of segments.
+ size_t
+ segment_count() const
+ { return this->segment_list_.size(); }
+
+ // Map from section flags to segment flags.
+ static elfcpp::Elf_Word
+ section_flags_to_segment(elfcpp::Elf_Xword flags);
+
+ // Attach sections to segments.
+ void
+ attach_sections_to_segments();
+
+ // For relaxation clean up, we need to know output section data created
+ // from a linker script.
+ void
+ new_output_section_data_from_script(Output_section_data* posd)
+ {
+ if (this->record_output_section_data_from_script_)
+ this->script_output_section_data_list_.push_back(posd);
+ }
+
+ // Return section list.
+ const Section_list&
+ section_list() const
+ { return this->section_list_; }
+
+ private:
+ Layout(const Layout&);
+ Layout& operator=(const Layout&);
+
+ // Mapping from input section names to output section names.
+ struct Section_name_mapping
+ {
+ const char* from;
+ int fromlen;
+ const char* to;
+ int tolen;
+ };
+ static const Section_name_mapping section_name_mapping[];
+ static const int section_name_mapping_count;
+
+ // During a relocatable link, a list of group sections and
+ // signatures.
+ struct Group_signature
+ {
+ // The group section.
+ Output_section* section;
+ // The signature.
+ const char* signature;
+
+ Group_signature()
+ : section(NULL), signature(NULL)
+ { }
+
+ Group_signature(Output_section* sectiona, const char* signaturea)
+ : section(sectiona), signature(signaturea)
+ { }
+ };
+ typedef std::vector<Group_signature> Group_signatures;
+
+ // Create a note section, filling in the header.
+ Output_section*
+ create_note(const char* name, int note_type, const char *section_name,
+ size_t descsz, bool allocate, size_t* trailing_padding);
+
+ // Create a note section for gold version.
+ void
+ create_gold_note();
+
+ // Record whether the stack must be executable.
+ void
+ create_executable_stack_info();
+
+ // Create a build ID note if needed.
+ void
+ create_build_id();
+
+ // Link .stab and .stabstr sections.
+ void
+ link_stabs_sections();
+
+ // Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed
+ // for the next run of incremental linking to check what has changed.
+ void
+ create_incremental_info_sections();
+
+ // Find the first read-only PT_LOAD segment, creating one if
+ // necessary.
+ Output_segment*
+ find_first_load_seg();
+
+ // Count the local symbols in the regular symbol table and the dynamic
+ // symbol table, and build the respective string pools.
+ void
+ count_local_symbols(const Task*, const Input_objects*);
+
+ // Create the output sections for the symbol table.
+ void
+ create_symtab_sections(const Input_objects*, Symbol_table*,
+ unsigned int, off_t*);
+
+ // Create the .shstrtab section.
+ Output_section*
+ create_shstrtab();
+
+ // Create the section header table.
+ void
+ create_shdrs(const Output_section* shstrtab_section, off_t*);
+
+ // Create the dynamic symbol table.
+ void
+ create_dynamic_symtab(const Input_objects*, Symbol_table*,
+ Output_section** pdynstr,
+ unsigned int* plocal_dynamic_count,
+ std::vector<Symbol*>* pdynamic_symbols,
+ Versions* versions);
+
+ // Assign offsets to each local portion of the dynamic symbol table.
+ void
+ assign_local_dynsym_offsets(const Input_objects*);
+
+ // Finish the .dynamic section and PT_DYNAMIC segment.
+ void
+ finish_dynamic_section(const Input_objects*, const Symbol_table*);
+
+ // Create the .interp section and PT_INTERP segment.
+ void
+ create_interp(const Target* target);
+
+ // Create the version sections.
+ void
+ create_version_sections(const Versions*,
+ const Symbol_table*,
+ unsigned int local_symcount,
+ const std::vector<Symbol*>& dynamic_symbols,
+ const Output_section* dynstr);
+
+ template<int size, bool big_endian>
+ void
+ sized_create_version_sections(const Versions* versions,
+ const Symbol_table*,
+ unsigned int local_symcount,
+ const std::vector<Symbol*>& dynamic_symbols,
+ const Output_section* dynstr);
+
+ // Return whether to include this section in the link.
+ template<int size, bool big_endian>
+ bool
+ include_section(Sized_relobj<size, big_endian>* object, const char* name,
+ const elfcpp::Shdr<size, big_endian>&);
+
+ // Return the output section name to use given an input section
+ // name. Set *PLEN to the length of the name. *PLEN must be
+ // initialized to the length of NAME.
+ static const char*
+ output_section_name(const char* name, size_t* plen);
+
+ // Return the number of allocated output sections.
+ size_t
+ allocated_output_section_count() const;
+
+ // Return the output section for NAME, TYPE and FLAGS.
+ Output_section*
+ get_output_section(const char* name, Stringpool::Key name_key,
+ elfcpp::Elf_Word type, elfcpp::Elf_Xword flags);
+
+ // Choose the output section for NAME in RELOBJ.
+ Output_section*
+ choose_output_section(const Relobj* relobj, const char* name,
+ elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
+ bool is_input_section);
+
+ // Create a new Output_section.
+ Output_section*
+ make_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags);
+
+ // Attach a section to a segment.
+ void
+ attach_section_to_segment(Output_section*);
+
+ // Attach an allocated section to a segment.
+ void
+ attach_allocated_section_to_segment(Output_section*);
+
+ // Set the final file offsets of all the segments.
+ off_t
+ set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx);
+
+ // Set the file offsets of the sections when doing a relocatable
+ // link.
+ off_t
+ set_relocatable_section_offsets(Output_data*, unsigned int* pshndx);
+
+ // Set the final file offsets of all the sections not associated
+ // with a segment. We set section offsets in three passes: the
+ // first handles all allocated sections, the second sections that
+ // require postprocessing, and the last the late-bound STRTAB
+ // sections (probably only shstrtab, which is the one we care about
+ // because it holds section names).
+ enum Section_offset_pass
+ {
+ BEFORE_INPUT_SECTIONS_PASS,
+ POSTPROCESSING_SECTIONS_PASS,
+ STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
+ };
+ off_t
+ set_section_offsets(off_t, Section_offset_pass pass);
+
+ // Set the final section indexes of all the sections not associated
+ // with a segment. Returns the next unused index.
+ unsigned int
+ set_section_indexes(unsigned int pshndx);
+
+ // Set the section addresses when using a script.
+ Output_segment*
+ set_section_addresses_from_script(Symbol_table*);
+
+ // Find appropriate places or orphan sections in a script.
+ void
+ place_orphan_sections_in_script();
+
+ // Return whether SEG1 comes before SEG2 in the output file.
+ static bool
+ segment_precedes(const Output_segment* seg1, const Output_segment* seg2);
+
+ // Use to save and restore segments during relaxation.
+ typedef Unordered_map<const Output_segment*, const Output_segment*>
+ Segment_states;
+
+ // Save states of current output segments.
+ void
+ save_segments(Segment_states*);
+
+ // Restore output segment states.
+ void
+ restore_segments(const Segment_states*);
+
+ // Clean up after relaxation so that it is possible to lay out the
+ // sections and segments again.
+ void
+ clean_up_after_relaxation();
+
+ // Doing preparation work for relaxation. This is factored out to make
+ // Layout::finalized a bit smaller and easier to read.
+ void
+ prepare_for_relaxation();
+
+ // Main body of the relaxation loop, which lays out the section.
+ off_t
+ relaxation_loop_body(int, Target*, Symbol_table*, Output_segment**,
+ Output_segment*, Output_segment_headers*,
+ Output_file_header*, unsigned int*);
+
+ // A mapping used for kept comdats/.gnu.linkonce group signatures.
+ typedef Unordered_map<std::string, Kept_section> Signatures;
+
+ // Mapping from input section name/type/flags to output section. We
+ // use canonicalized strings here.
+
+ typedef std::pair<Stringpool::Key,
+ std::pair<elfcpp::Elf_Word, elfcpp::Elf_Xword> > Key;
+
+ struct Hash_key
+ {
+ size_t
+ operator()(const Key& k) const;
+ };
+
+ typedef Unordered_map<Key, Output_section*, Hash_key> Section_name_map;
+
+ // A comparison class for segments.
+
+ struct Compare_segments
+ {
+ bool
+ operator()(const Output_segment* seg1, const Output_segment* seg2)
+ { return Layout::segment_precedes(seg1, seg2); }
+ };
+
+ typedef std::vector<Output_section_data*> Output_section_data_list;
+
+ // Debug checker class.
+ class Relaxation_debug_check
+ {
+ public:
+ Relaxation_debug_check()
+ : section_infos_()
+ { }
+
+ // Check that sections and special data are in reset states.
+ void
+ check_output_data_for_reset_values(const Layout::Section_list&,
+ const Layout::Data_list&);
+
+ // Record information of a section list.
+ void
+ read_sections(const Layout::Section_list&);
+
+ // Verify a section list with recorded information.
+ void
+ verify_sections(const Layout::Section_list&);
+
+ private:
+ // Information we care about a section.
+ struct Section_info
+ {
+ // Output section described by this.
+ Output_section* output_section;
+ // Load address.
+ uint64_t address;
+ // Data size.
+ off_t data_size;
+ // File offset.
+ off_t offset;
+ };
+
+ // Section information.
+ std::vector<Section_info> section_infos_;
+ };
+
+ // The number of input files, for sizing tables.
+ int number_of_input_files_;
+ // Information set by scripts or by command line options.
+ Script_options* script_options_;
+ // The output section names.
+ Stringpool namepool_;
+ // The output symbol names.
+ Stringpool sympool_;
+ // The dynamic strings, if needed.
+ Stringpool dynpool_;
+ // The list of group sections and linkonce sections which we have seen.
+ Signatures signatures_;
+ // The mapping from input section name/type/flags to output sections.
+ Section_name_map section_name_map_;
+ // The list of output segments.
+ Segment_list segment_list_;
+ // The list of output sections.
+ Section_list section_list_;
+ // The list of output sections which are not attached to any output
+ // segment.
+ Section_list unattached_section_list_;
+ // The list of unattached Output_data objects which require special
+ // handling because they are not Output_sections.
+ Data_list special_output_list_;
+ // The section headers.
+ Output_section_headers* section_headers_;
+ // A pointer to the PT_TLS segment if there is one.
+ Output_segment* tls_segment_;
+ // A pointer to the PT_GNU_RELRO segment if there is one.
+ Output_segment* relro_segment_;
+ // The SHT_SYMTAB output section.
+ Output_section* symtab_section_;
+ // The SHT_SYMTAB_SHNDX for the regular symbol table if there is one.
+ Output_symtab_xindex* symtab_xindex_;
+ // The SHT_DYNSYM output section if there is one.
+ Output_section* dynsym_section_;
+ // The SHT_SYMTAB_SHNDX for the dynamic symbol table if there is one.
+ Output_symtab_xindex* dynsym_xindex_;
+ // The SHT_DYNAMIC output section if there is one.
+ Output_section* dynamic_section_;
+ // The dynamic data which goes into dynamic_section_.
+ Output_data_dynamic* dynamic_data_;
+ // The exception frame output section if there is one.
+ Output_section* eh_frame_section_;
+ // The exception frame data for eh_frame_section_.
+ Eh_frame* eh_frame_data_;
+ // Whether we have added eh_frame_data_ to the .eh_frame section.
+ bool added_eh_frame_data_;
+ // The exception frame header output section if there is one.
+ Output_section* eh_frame_hdr_section_;
+ // The space for the build ID checksum if there is one.
+ Output_section_data* build_id_note_;
+ // The output section containing dwarf abbreviations
+ Output_reduced_debug_abbrev_section* debug_abbrev_;
+ // The output section containing the dwarf debug info tree
+ Output_reduced_debug_info_section* debug_info_;
+ // A list of group sections and their signatures.
+ Group_signatures group_signatures_;
+ // The size of the output file.
+ off_t output_file_size_;
+ // Whether we have attached the sections to the segments.
+ bool sections_are_attached_;
+ // Whether we have seen an object file marked to require an
+ // executable stack.
+ bool input_requires_executable_stack_;
+ // Whether we have seen at least one object file with an executable
+ // stack marker.
+ bool input_with_gnu_stack_note_;
+ // Whether we have seen at least one object file without an
+ // executable stack marker.
+ bool input_without_gnu_stack_note_;
+ // Whether we have seen an object file that uses the static TLS model.
+ bool has_static_tls_;
+ // Whether any sections require postprocessing.
+ bool any_postprocessing_sections_;
+ // Whether we have resized the signatures_ hash table.
+ bool resized_signatures_;
+ // Whether we have created a .stab*str output section.
+ bool have_stabstr_section_;
+ // In incremental build, holds information check the inputs and build the
+ // .gnu_incremental_inputs section.
+ Incremental_inputs* incremental_inputs_;
+ // Whether we record output section data created in script
+ bool record_output_section_data_from_script_;
+ // List of output data that needs to be removed at relexation clean up.
+ Output_section_data_list script_output_section_data_list_;
+ // Structure to save segment states before entering the relaxation loop.
+ Segment_states* segment_states_;
+ // A relaxation debug checker. We only create one when in debugging mode.
+ Relaxation_debug_check* relaxation_debug_check_;
+};
+
+// This task handles writing out data in output sections which is not
+// part of an input section, or which requires special handling. When
+// this is done, it unblocks both output_sections_blocker and
+// final_blocker.
+
+class Write_sections_task : public Task
+{
+ public:
+ Write_sections_task(const Layout* layout, Output_file* of,
+ Task_token* output_sections_blocker,
+ Task_token* final_blocker)
+ : layout_(layout), of_(of),
+ output_sections_blocker_(output_sections_blocker),
+ final_blocker_(final_blocker)
+ { }
+
+ // The standard Task methods.
+
+ Task_token*
+ is_runnable();
+
+ void
+ locks(Task_locker*);
+
+ void
+ run(Workqueue*);
+
+ std::string
+ get_name() const
+ { return "Write_sections_task"; }
+
+ private:
+ class Write_sections_locker;
+
+ const Layout* layout_;
+ Output_file* of_;
+ Task_token* output_sections_blocker_;
+ Task_token* final_blocker_;
+};
+
+// This task handles writing out data which is not part of a section
+// or segment.
+
+class Write_data_task : public Task
+{
+ public:
+ Write_data_task(const Layout* layout, const Symbol_table* symtab,
+ Output_file* of, Task_token* final_blocker)
+ : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker)
+ { }
+
+ // The standard Task methods.
+
+ Task_token*
+ is_runnable();
+
+ void
+ locks(Task_locker*);
+
+ void
+ run(Workqueue*);
+
+ std::string
+ get_name() const
+ { return "Write_data_task"; }
+
+ private:
+ const Layout* layout_;
+ const Symbol_table* symtab_;
+ Output_file* of_;
+ Task_token* final_blocker_;
+};
+
+// This task handles writing out the global symbols.
+
+class Write_symbols_task : public Task
+{
+ public:
+ Write_symbols_task(const Layout* layout, const Symbol_table* symtab,
+ const Input_objects* input_objects,
+ const Stringpool* sympool, const Stringpool* dynpool,
+ Output_file* of, Task_token* final_blocker)
+ : layout_(layout), symtab_(symtab), input_objects_(input_objects),
+ sympool_(sympool), dynpool_(dynpool), of_(of),
+ final_blocker_(final_blocker)
+ { }
+
+ // The standard Task methods.
+
+ Task_token*
+ is_runnable();
+
+ void
+ locks(Task_locker*);
+
+ void
+ run(Workqueue*);
+
+ std::string
+ get_name() const
+ { return "Write_symbols_task"; }
+
+ private:
+ const Layout* layout_;
+ const Symbol_table* symtab_;
+ const Input_objects* input_objects_;
+ const Stringpool* sympool_;
+ const Stringpool* dynpool_;
+ Output_file* of_;
+ Task_token* final_blocker_;
+};
+
+// This task handles writing out data in output sections which can't
+// be written out until all the input sections have been handled.
+// This is for sections whose contents is based on the contents of
+// other output sections.
+
+class Write_after_input_sections_task : public Task
+{
+ public:
+ Write_after_input_sections_task(Layout* layout, Output_file* of,
+ Task_token* input_sections_blocker,
+ Task_token* final_blocker)
+ : layout_(layout), of_(of),
+ input_sections_blocker_(input_sections_blocker),
+ final_blocker_(final_blocker)
+ { }
+
+ // The standard Task methods.
+
+ Task_token*
+ is_runnable();
+
+ void
+ locks(Task_locker*);
+
+ void
+ run(Workqueue*);
+
+ std::string
+ get_name() const
+ { return "Write_after_input_sections_task"; }
+
+ private:
+ Layout* layout_;
+ Output_file* of_;
+ Task_token* input_sections_blocker_;
+ Task_token* final_blocker_;
+};
+
+// This task function handles closing the file.
+
+class Close_task_runner : public Task_function_runner
+{
+ public:
+ Close_task_runner(const General_options* options, const Layout* layout,
+ Output_file* of)
+ : options_(options), layout_(layout), of_(of)
+ { }
+
+ // Run the operation.
+ void
+ run(Workqueue*, const Task*);
+
+ private:
+ const General_options* options_;
+ const Layout* layout_;
+ Output_file* of_;
+};
+
+// A small helper function to align an address.
+
+inline uint64_t
+align_address(uint64_t address, uint64_t addralign)
+{
+ if (addralign != 0)
+ address = (address + addralign - 1) &~ (addralign - 1);
+ return address;
+}
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_LAYOUT_H)
projects / msp430-binutils.git / blobdiff