// layout.h -- lay out output file sections for gold -*- C++ -*-
+// Copyright 2006, 2007 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 "workqueue.h"
#include "object.h"
+#include "dynobj.h"
#include "stringpool.h"
namespace gold
class Output_segment;
class Output_data;
class Output_data_dynamic;
+class Eh_frame;
class Target;
// This task function handles mapping the input sections to output
// Run the operation.
void
- run(Workqueue*);
+ run(Workqueue*, const Task*);
private:
Layout_task_runner(const Layout_task_runner&);
// 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. Set *OFFSET to the offset within the
- // output section.
+ // 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(Relobj *object, unsigned int shndx, const char* name,
- const elfcpp::Shdr<size, big_endian>& shdr, off_t* offset);
+ 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);
+
+ // 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.
void
create_initial_dynamic_sections(const Input_objects*, Symbol_table*);
+ // Define __start and __stop symbols for output sections.
+ void
+ define_section_symbols(Symbol_table*, const Target*);
+
// Return the Stringpool used for symbol names.
const Stringpool*
sympool() const
// Finalize the layout after all the input sections have been added.
off_t
- finalize(const Input_objects*, Symbol_table*);
+ finalize(const Input_objects*, Symbol_table*, 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.
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*, const Target*, Output_file*) const;
+ 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_segment(elfcpp::PT type, elfcpp::Elf_Word set,
elfcpp::Elf_Word clear) 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_; }
+
+ // Dump statistical information to stderr.
+ void
+ print_stats() const;
+
// The list of segments.
typedef std::vector<Output_segment*> Segment_list;
static const Linkonce_mapping linkonce_mapping[];
static const int linkonce_mapping_count;
+ // Create a .note section for gold.
+ void
+ create_gold_note();
+
+ // Record whether the stack must be executable.
+ void
+ create_executable_stack_info(const Target*);
+
// 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(int size, const Input_objects*, Symbol_table*,
+ create_symtab_sections(const Input_objects*, Symbol_table*, const Task*,
off_t*);
// Create the .shstrtab section.
create_shstrtab();
// Create the section header table.
- Output_section_headers*
- create_shdrs(int size, bool big_endian, off_t*);
+ void
+ create_shdrs(off_t*);
// Create the dynamic symbol table.
void
- create_dynamic_symtab(const Target*, Symbol_table*);
+ create_dynamic_symtab(const Input_objects*, const Target*,
+ 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
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
+ ACCEPT_SIZE_ENDIAN);
+
// Return whether to include this section in the link.
template<int size, bool big_endian>
bool
- include_section(Object* object, const char* name,
+ 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
off_t
set_segment_offsets(const Target*, Output_segment*, unsigned int* pshndx);
- // Set the final file offsets and section indices of all the
- // sections not associated with a segment.
+ // 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, unsigned int *pshndx);
+ 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);
// Return whether SEG1 comes before SEG2 in the output file.
static bool
// 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_;
// The SHT_SYMTAB output section.
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_;
+ // The exception frame header output section if there is one.
+ Output_section* eh_frame_hdr_section_;
+ // The size of the output file.
+ off_t output_file_size_;
+ // 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_;
+};
+
+// 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
{
public:
Write_data_task(const Layout* layout, const Symbol_table* symtab,
- const Target* target, Output_file* of,
- Task_token* final_blocker)
- : layout_(layout), symtab_(symtab), target_(target), of_(of),
- final_blocker_(final_blocker)
+ Output_file* of, Task_token* final_blocker)
+ : layout_(layout), symtab_(symtab), of_(of), final_blocker_(final_blocker)
{ }
// The standard Task methods.
- Is_runnable_type
- is_runnable(Workqueue*);
+ Task_token*
+ is_runnable();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
+ std::string
+ get_name() const
+ { return "Write_data_task"; }
+
private:
const Layout* layout_;
const Symbol_table* symtab_;
- const Target* target_;
Output_file* of_;
Task_token* final_blocker_;
};
class Write_symbols_task : public Task
{
public:
- Write_symbols_task(const Symbol_table* symtab, const Target* target,
+ Write_symbols_task(const Symbol_table* symtab,
+ const Input_objects* input_objects,
const Stringpool* sympool, const Stringpool* dynpool,
Output_file* of, Task_token* final_blocker)
- : symtab_(symtab), target_(target), sympool_(sympool), dynpool_(dynpool),
- of_(of), final_blocker_(final_blocker)
+ : symtab_(symtab), input_objects_(input_objects), sympool_(sympool),
+ dynpool_(dynpool), of_(of), final_blocker_(final_blocker)
{ }
// The standard Task methods.
- Is_runnable_type
- is_runnable(Workqueue*);
+ Task_token*
+ is_runnable();
- Task_locker*
- locks(Workqueue*);
+ void
+ locks(Task_locker*);
void
run(Workqueue*);
+ std::string
+ get_name() const
+ { return "Write_symbols_task"; }
+
private:
const Symbol_table* symtab_;
- const Target* target_;
+ 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
// Run the operation.
void
- run(Workqueue*);
+ run(Workqueue*, const Task*);
private:
Output_file* of_;