mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-12-15 16:19:24 +00:00
17a1d0a9b2
reduces the amount of locking required to find a new thread to run.
663 lines
19 KiB
C++
663 lines
19 KiB
C++
// 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 <list>
|
|
#include <string>
|
|
#include <utility>
|
|
#include <vector>
|
|
|
|
#include "workqueue.h"
|
|
#include "object.h"
|
|
#include "dynobj.h"
|
|
#include "stringpool.h"
|
|
|
|
namespace gold
|
|
{
|
|
|
|
class General_options;
|
|
class Input_objects;
|
|
class Symbol_table;
|
|
class Output_section_data;
|
|
class Output_section;
|
|
class Output_section_headers;
|
|
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
|
|
// 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,
|
|
Layout* layout)
|
|
: options_(options), input_objects_(input_objects), symtab_(symtab),
|
|
layout_(layout)
|
|
{ }
|
|
|
|
// 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_;
|
|
Layout* layout_;
|
|
};
|
|
|
|
// This class handles the details of laying out input sections.
|
|
|
|
class Layout
|
|
{
|
|
public:
|
|
Layout(const General_options& options);
|
|
|
|
// 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);
|
|
|
|
// 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
|
|
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(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
|
|
{ return &this->sympool_; }
|
|
|
|
// Return the Stringpool used for dynamic symbol names and dynamic
|
|
// tags.
|
|
const Stringpool*
|
|
dynpool() const
|
|
{ return &this->dynpool_; }
|
|
|
|
// 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; }
|
|
|
|
// Record the signature of a comdat section, and return whether to
|
|
// include it in the link. The GROUP parameter is true for a
|
|
// section group signature, false for a signature derived from a
|
|
// .gnu.linkonce section.
|
|
bool
|
|
add_comdat(const char*, bool group);
|
|
|
|
// Finalize the layout after all the input sections have been added.
|
|
off_t
|
|
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.
|
|
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;
|
|
|
|
// 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;
|
|
|
|
// The list of sections not attached to a segment.
|
|
|
|
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;
|
|
|
|
private:
|
|
Layout(const Layout&);
|
|
Layout& operator=(const Layout&);
|
|
|
|
// Mapping from .gnu.linkonce section names to output section names.
|
|
struct Linkonce_mapping
|
|
{
|
|
const char* from;
|
|
int fromlen;
|
|
const char* to;
|
|
int tolen;
|
|
};
|
|
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(const Input_objects*, Symbol_table*, const Task*,
|
|
off_t*);
|
|
|
|
// Create the .shstrtab section.
|
|
Output_section*
|
|
create_shstrtab();
|
|
|
|
// Create the section header table.
|
|
void
|
|
create_shdrs(off_t*);
|
|
|
|
// Create the dynamic symbol table.
|
|
void
|
|
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
|
|
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
|
|
ACCEPT_SIZE_ENDIAN);
|
|
|
|
// 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 output section name to use for a linkonce section
|
|
// name. PLEN is as for output_section_name.
|
|
static const char*
|
|
linkonce_output_name(const char* name, size_t* plen);
|
|
|
|
// 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);
|
|
|
|
// Create a new Output_section.
|
|
Output_section*
|
|
make_output_section(const char* name, elfcpp::Elf_Word type,
|
|
elfcpp::Elf_Xword flags);
|
|
|
|
// Set the final file offsets of all the segments.
|
|
off_t
|
|
set_segment_offsets(const Target*, Output_segment*, 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);
|
|
|
|
// Return whether SEG1 comes before SEG2 in the output file.
|
|
static bool
|
|
segment_precedes(const Output_segment* seg1, const Output_segment* seg2);
|
|
|
|
// Map from section flags to segment flags.
|
|
static elfcpp::Elf_Word
|
|
section_flags_to_segment(elfcpp::Elf_Xword flags);
|
|
|
|
// A mapping used for group signatures.
|
|
typedef Unordered_map<std::string, bool> 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); }
|
|
};
|
|
|
|
// A reference to the options on the command line.
|
|
const General_options& 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_;
|
|
// The SHT_SYMTAB output section.
|
|
Output_section* symtab_section_;
|
|
// The SHT_DYNSYM output section if there is one.
|
|
Output_section* dynsym_section_;
|
|
// 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_;
|
|
// 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
|
|
// 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 Symbol_table* symtab,
|
|
const Input_objects* input_objects,
|
|
const Stringpool* sympool, const Stringpool* dynpool,
|
|
Output_file* of, Task_token* final_blocker)
|
|
: 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 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(Output_file* of)
|
|
: of_(of)
|
|
{ }
|
|
|
|
// Run the operation.
|
|
void
|
|
run(Workqueue*, const Task*);
|
|
|
|
private:
|
|
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)
|