// object.h -- support for an object file for linking in 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_OBJECT_H
#define GOLD_OBJECT_H
-#include <cassert>
+#include <string>
#include <vector>
#include "elfcpp.h"
+#include "elfcpp_file.h"
#include "fileread.h"
#include "target.h"
-#include "symtab.h"
namespace gold
{
-class Stringpool;
-class Output_section;
+class General_options;
+class Task;
class Layout;
+class Output_section;
+class Output_file;
+class Dynobj;
+class Object_merge_map;
+
+template<typename Stringpool_char>
+class Stringpool_template;
// Data to pass from read_symbols() to add_symbols().
struct Read_symbols_data
{
+ // Section headers.
+ File_view* section_headers;
+ // Section names.
+ File_view* section_names;
+ // Size of section name data in bytes.
+ section_size_type section_names_size;
// Symbol data.
File_view* symbols;
// Size of symbol data in bytes.
- off_t symbols_size;
+ section_size_type symbols_size;
+ // Offset of external symbols within symbol data. This structure
+ // sometimes contains only external symbols, in which case this will
+ // be zero. Sometimes it contains all symbols.
+ section_offset_type external_symbols_offset;
// Symbol names.
File_view* symbol_names;
// Size of symbol name data in bytes.
- off_t symbol_names_size;
+ section_size_type symbol_names_size;
+
+ // Version information. This is only used on dynamic objects.
+ // Version symbol data (from SHT_GNU_versym section).
+ File_view* versym;
+ section_size_type versym_size;
+ // Version definition data (from SHT_GNU_verdef section).
+ File_view* verdef;
+ section_size_type verdef_size;
+ unsigned int verdef_info;
+ // Needed version data (from SHT_GNU_verneed section).
+ File_view* verneed;
+ section_size_type verneed_size;
+ unsigned int verneed_info;
+};
+
+// Information used to print error messages.
+
+struct Symbol_location_info
+{
+ std::string source_file;
+ std::string enclosing_symbol_name;
+ int line_number;
};
-// Object is an interface which represents either a 32-bit or a 64-bit
-// input object. This can be a regular object file (ET_REL) or a
-// shared object (ET_DYN). The actual instantiations are
-// Sized_object<32> and Sized_object<64>
+// Data about a single relocation section. This is read in
+// read_relocs and processed in scan_relocs.
+
+struct Section_relocs
+{
+ // Index of reloc section.
+ unsigned int reloc_shndx;
+ // Index of section that relocs apply to.
+ unsigned int data_shndx;
+ // Contents of reloc section.
+ File_view* contents;
+ // Reloc section type.
+ unsigned int sh_type;
+ // Number of reloc entries.
+ size_t reloc_count;
+ // Output section.
+ Output_section* output_section;
+ // Whether this section has special handling for offsets.
+ bool needs_special_offset_handling;
+};
+
+// Relocations in an object file. This is read in read_relocs and
+// processed in scan_relocs.
+
+struct Read_relocs_data
+{
+ typedef std::vector<Section_relocs> Relocs_list;
+ // The relocations.
+ Relocs_list relocs;
+ // The local symbols.
+ File_view* local_symbols;
+};
+
+// Object is an abstract base class which represents either a 32-bit
+// or a 64-bit input object. This can be a regular object file
+// (ET_REL) or a shared object (ET_DYN).
class Object
{
// file--0 for a .o or .so file, something else for a .a file.
Object(const std::string& name, Input_file* input_file, bool is_dynamic,
off_t offset = 0)
- : name_(name), input_file_(input_file), offset_(offset),
- shnum_(0), is_dynamic_(is_dynamic), target_(NULL),
- map_to_output_()
+ : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
+ is_dynamic_(is_dynamic), target_(NULL)
{ }
virtual ~Object()
name() const
{ return this->name_; }
+ // Get the offset into the file.
+ off_t
+ offset() const
+ { return this->offset_; }
+
// Return whether this is a dynamic object.
bool
is_dynamic() const
// Lock the underlying file.
void
- lock()
- { this->input_file_->file().lock(); }
+ lock(const Task* t)
+ { this->input_file()->file().lock(t); }
// Unlock the underlying file.
void
- unlock()
- { this->input_file_->file().unlock(); }
+ unlock(const Task* t)
+ { this->input_file()->file().unlock(t); }
// Return whether the underlying file is locked.
bool
is_locked() const
- { return this->input_file_->file().is_locked(); }
+ { return this->input_file()->file().is_locked(); }
+
+ // Return the token, so that the task can be queued.
+ Task_token*
+ token()
+ { return this->input_file()->file().token(); }
+
+ // Release the underlying file.
+ void
+ release()
+ { this->input_file_->file().release(); }
-#ifdef HAVE_MEMBER_TEMPLATE_SPECIFICATIONS
// Return the sized target structure associated with this object.
// This is like the target method but it returns a pointer of
// appropriate checked type.
template<int size, bool big_endian>
Sized_target<size, big_endian>*
- sized_target();
-#endif
+ sized_target(ACCEPT_SIZE_ENDIAN_ONLY) const;
+
+ // Get the number of sections.
+ unsigned int
+ shnum() const
+ { return this->shnum_; }
- // Read the symbol and relocation information.
- Read_symbols_data
- read_symbols()
- { return this->do_read_symbols(); }
+ // Return a view of the contents of a section. Set *PLEN to the
+ // size. CACHE is a hint as in File_read::get_view.
+ const unsigned char*
+ section_contents(unsigned int shndx, section_size_type* plen, bool cache);
- // Add symbol information to the global symbol table.
+ // Return the name of a section given a section index. This is only
+ // used for error messages.
+ std::string
+ section_name(unsigned int shndx)
+ { return this->do_section_name(shndx); }
+
+ // Return the section flags given a section index.
+ uint64_t
+ section_flags(unsigned int shndx)
+ { return this->do_section_flags(shndx); }
+
+ // Return the section type given a section index.
+ unsigned int
+ section_type(unsigned int shndx)
+ { return this->do_section_type(shndx); }
+
+ // Return the section link field given a section index.
+ unsigned int
+ section_link(unsigned int shndx)
+ { return this->do_section_link(shndx); }
+
+ // Return the section info field given a section index.
+ unsigned int
+ section_info(unsigned int shndx)
+ { return this->do_section_info(shndx); }
+
+ // Read the symbol information.
void
- add_symbols(Symbol_table* symtab, Read_symbols_data rd)
- { this->do_add_symbols(symtab, rd); }
+ read_symbols(Read_symbols_data* sd)
+ { return this->do_read_symbols(sd); }
// Pass sections which should be included in the link to the Layout
// object, and record where the sections go in the output file.
void
- layout(Layout* lay)
- { this->do_layout(lay); }
+ layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd)
+ { this->do_layout(symtab, layout, sd); }
- // Initial local symbol processing: set the offset where local
- // symbol information will be stored; add local symbol names to
- // *POOL; return the offset following the local symbols.
- off_t
- finalize_local_symbols(off_t off, Stringpool* pool)
- { return this->do_finalize_local_symbols(off, pool); }
+ // Add symbol information to the global symbol table.
+ void
+ add_symbols(Symbol_table* symtab, Read_symbols_data* sd)
+ { this->do_add_symbols(symtab, sd); }
- // What we need to know to map an input section to an output
- // section. We keep an array of these, one for each input section,
- // indexed by the input section number.
- struct Map_to_output
+ // Functions and types for the elfcpp::Elf_file interface. This
+ // permit us to use Object as the File template parameter for
+ // elfcpp::Elf_file.
+
+ // The View class is returned by view. It must support a single
+ // method, data(). This is trivial, because get_view does what we
+ // need.
+ class View
{
- // The output section. This is NULL if the input section is to be
- // discarded.
- Output_section* output_section;
- // The offset within the output section.
- off_t offset;
+ public:
+ View(const unsigned char* p)
+ : p_(p)
+ { }
+
+ const unsigned char*
+ data() const
+ { return this->p_; }
+
+ private:
+ const unsigned char* p_;
+ };
+
+ // Return a View.
+ View
+ view(off_t file_offset, section_size_type data_size)
+ { return View(this->get_view(file_offset, data_size, true)); }
+
+ // Report an error.
+ void
+ error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
+
+ // A location in the file.
+ struct Location
+ {
+ off_t file_offset;
+ off_t data_size;
+
+ Location(off_t fo, section_size_type ds)
+ : file_offset(fo), data_size(ds)
+ { }
};
- // Given a section index, return the corresponding Map_to_output
- // information.
- const Map_to_output*
- section_output_info(unsigned int shnum) const
- { return &this->map_to_output_[shnum]; }
+ // Get a View given a Location.
+ View view(Location loc)
+ { return View(this->get_view(loc.file_offset, loc.data_size, true)); }
protected:
// Read the symbols--implemented by child class.
- virtual Read_symbols_data
- do_read_symbols() = 0;
+ virtual void
+ do_read_symbols(Read_symbols_data*) = 0;
+
+ // Lay out sections--implemented by child class.
+ virtual void
+ do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0;
// Add symbol information to the global symbol table--implemented by
// child class.
virtual void
- do_add_symbols(Symbol_table*, Read_symbols_data) = 0;
+ do_add_symbols(Symbol_table*, Read_symbols_data*) = 0;
- // Lay out sections--implemented by child class.
- virtual void
- do_layout(Layout*) = 0;
+ // Return the location of the contents of a section. Implemented by
+ // child class.
+ virtual Location
+ do_section_contents(unsigned int shndx) = 0;
+
+ // Get the name of a section--implemented by child class.
+ virtual std::string
+ do_section_name(unsigned int shndx) = 0;
- // Finalize local symbols--implemented by child class.
- virtual off_t
- do_finalize_local_symbols(off_t, Stringpool*) = 0;
+ // Get section flags--implemented by child class.
+ virtual uint64_t
+ do_section_flags(unsigned int shndx) = 0;
- // Get the file.
+ // Get section type--implemented by child class.
+ virtual unsigned int
+ do_section_type(unsigned int shndx) = 0;
+
+ // Get section link field--implemented by child class.
+ virtual unsigned int
+ do_section_link(unsigned int shndx) = 0;
+
+ // Get section info field--implemented by child class.
+ virtual unsigned int
+ do_section_info(unsigned int shndx) = 0;
+
+ // Get the file. We pass on const-ness.
Input_file*
- input_file() const
+ input_file()
{ return this->input_file_; }
- // Get the offset into the file.
- off_t
- offset() const
- { return this->offset_; }
+ const Input_file*
+ input_file() const
+ { return this->input_file_; }
// Get a view into the underlying file.
const unsigned char*
- get_view(off_t start, off_t size);
+ get_view(off_t start, section_size_type size, bool cache)
+ {
+ return this->input_file()->file().get_view(start + this->offset_, size,
+ cache);
+ }
- // Get the number of sections.
- unsigned int
- shnum() const
- { return this->shnum_; }
+ // Get a lasting view into the underlying file.
+ File_view*
+ get_lasting_view(off_t start, section_size_type size, bool cache)
+ {
+ return this->input_file()->file().get_lasting_view(start + this->offset_,
+ size, cache);
+ }
- // Set the number of sections.
+ // Read data from the underlying file.
void
- set_shnum(int shnum)
- { this->shnum_ = shnum; }
+ read(off_t start, section_size_type size, void* p) const
+ { this->input_file()->file().read(start + this->offset_, size, p); }
// Set the target.
void
- set_target(Target* target)
- { this->target_ = target; }
+ set_target(int machine, int size, bool big_endian, int osabi,
+ int abiversion);
- // Read data from the underlying file.
+ // Set the number of sections.
void
- read(off_t start, off_t size, void* p);
+ set_shnum(int shnum)
+ { this->shnum_ = shnum; }
- // Get a lasting view into the underlying file.
- File_view*
- get_lasting_view(off_t start, off_t size);
+ // Functions used by both Sized_relobj and Sized_dynobj.
- // Return the vector mapping input sections to output sections.
- std::vector<Map_to_output>&
- map_to_output()
- { return this->map_to_output_; }
+ // Read the section data into a Read_symbols_data object.
+ template<int size, bool big_endian>
+ void
+ read_section_data(elfcpp::Elf_file<size, big_endian, Object>*,
+ Read_symbols_data*);
+
+ // If NAME is the name of a special .gnu.warning section, arrange
+ // for the warning to be issued. SHNDX is the section index.
+ // Return whether it is a warning section.
+ bool
+ handle_gnu_warning_section(const char* name, unsigned int shndx,
+ Symbol_table*);
private:
// This class may not be copied.
Object(const Object&);
Object& operator=(const Object&);
- // Name of object as printed to use.
+ // Name of object as printed to user.
std::string name_;
// For reading the file.
Input_file* input_file_;
bool is_dynamic_;
// Target functions--may be NULL if the target is not known.
Target* target_;
- // Mapping from input sections to output section.
- std::vector<Map_to_output> map_to_output_;
};
-#ifdef HAVE_MEMBER_TEMPLATE_SPECIFICATIONS
-
// Implement sized_target inline for efficiency. This approach breaks
// static type checking, but is made safe using asserts.
template<int size, bool big_endian>
inline Sized_target<size, big_endian>*
-Object::sized_target()
+Object::sized_target(ACCEPT_SIZE_ENDIAN_ONLY) const
{
- assert(this->target_->get_size() == size);
- assert(this->target_->is_big_endian() ? big_endian : !big_endian);
+ gold_assert(this->target_->get_size() == size);
+ gold_assert(this->target_->is_big_endian() ? big_endian : !big_endian);
return static_cast<Sized_target<size, big_endian>*>(this->target_);
}
-#endif
+// A regular object (ET_REL). This is an abstract base class itself.
+// The implementation is the template class Sized_relobj.
+
+class Relobj : public Object
+{
+ public:
+ Relobj(const std::string& name, Input_file* input_file, off_t offset = 0)
+ : Object(name, input_file, false, offset),
+ map_to_output_(),
+ object_merge_map_(NULL),
+ relocs_must_follow_section_writes_(false)
+ { }
+
+ // Read the relocs.
+ void
+ read_relocs(Read_relocs_data* rd)
+ { return this->do_read_relocs(rd); }
+
+ // Scan the relocs and adjust the symbol table.
+ void
+ scan_relocs(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Read_relocs_data* rd)
+ { return this->do_scan_relocs(options, symtab, layout, rd); }
+
+ // The number of local symbols in the input symbol table.
+ virtual unsigned int
+ local_symbol_count() const
+ { return this->do_local_symbol_count(); }
+
+ // Initial local symbol processing: count the number of local symbols
+ // in the output symbol table and dynamic symbol table; add local symbol
+ // names to *POOL and *DYNPOOL.
+ void
+ count_local_symbols(Stringpool_template<char>* pool,
+ Stringpool_template<char>* dynpool)
+ { return this->do_count_local_symbols(pool, dynpool); }
+
+ // Set the values of the local symbols, set the output symbol table
+ // indexes for the local variables, and set the offset where local
+ // symbol information will be stored. Returns the new local symbol index.
+ unsigned int
+ finalize_local_symbols(unsigned int index, off_t off)
+ { return this->do_finalize_local_symbols(index, off); }
+
+ // Set the output dynamic symbol table indexes for the local variables.
+ unsigned int
+ set_local_dynsym_indexes(unsigned int index)
+ { return this->do_set_local_dynsym_indexes(index); }
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ set_local_dynsym_offset(off_t off)
+ { return this->do_set_local_dynsym_offset(off); }
+
+ // Relocate the input sections and write out the local symbols.
+ void
+ relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout* layout, Output_file* of)
+ { return this->do_relocate(options, symtab, layout, of); }
+
+ // Return whether an input section is being included in the link.
+ bool
+ is_section_included(unsigned int shndx) const
+ {
+ gold_assert(shndx < this->map_to_output_.size());
+ return this->map_to_output_[shndx].output_section != NULL;
+ }
+
+ // Return whether an input section requires special
+ // handling--whether it is not simply mapped from the input file to
+ // the output file.
+ bool
+ is_section_specially_mapped(unsigned int shndx) const
+ {
+ gold_assert(shndx < this->map_to_output_.size());
+ return (this->map_to_output_[shndx].output_section != NULL
+ && this->map_to_output_[shndx].offset == -1);
+ }
+
+ // Given a section index, return the corresponding Output_section
+ // (which will be NULL if the section is not included in the link)
+ // and set *POFF to the offset within that section. *POFF will be
+ // set to -1 if the section requires special handling.
+ inline Output_section*
+ output_section(unsigned int shndx, section_offset_type* poff) const;
+
+ // Set the offset of an input section within its output section.
+ void
+ set_section_offset(unsigned int shndx, section_offset_type off)
+ {
+ gold_assert(shndx < this->map_to_output_.size());
+ this->map_to_output_[shndx].offset = off;
+ }
+
+ // Return true if we need to wait for output sections to be written
+ // before we can apply relocations. This is true if the object has
+ // any relocations for sections which require special handling, such
+ // as the exception frame section.
+ bool
+ relocs_must_follow_section_writes() const
+ { return this->relocs_must_follow_section_writes_; }
+
+ // Return the object merge map.
+ Object_merge_map*
+ merge_map() const
+ { return this->object_merge_map_; }
+
+ // Set the object merge map.
+ void
+ set_merge_map(Object_merge_map* object_merge_map)
+ {
+ gold_assert(this->object_merge_map_ == NULL);
+ this->object_merge_map_ = object_merge_map;
+ }
+
+ protected:
+ // What we need to know to map an input section to an output
+ // section. We keep an array of these, one for each input section,
+ // indexed by the input section number.
+ struct Map_to_output
+ {
+ // The output section. This is NULL if the input section is to be
+ // discarded.
+ Output_section* output_section;
+ // The offset within the output section. This is -1 if the
+ // section requires special handling.
+ section_offset_type offset;
+ };
+
+ // Read the relocs--implemented by child class.
+ virtual void
+ do_read_relocs(Read_relocs_data*) = 0;
+
+ // Scan the relocs--implemented by child class.
+ virtual void
+ do_scan_relocs(const General_options&, Symbol_table*, Layout*,
+ Read_relocs_data*) = 0;
+
+ // Return the number of local symbols--implemented by child class.
+ virtual unsigned int
+ do_local_symbol_count() const = 0;
+
+ // Count local symbols--implemented by child class.
+ virtual void
+ do_count_local_symbols(Stringpool_template<char>*,
+ Stringpool_template<char>*) = 0;
+
+ // Finalize the local symbols. Set the output symbol table indexes for the local variables, and set the
+ // offset where local symbol information will be stored.
+ virtual unsigned int
+ do_finalize_local_symbols(unsigned int, off_t) = 0;
+
+ // Set the output dynamic symbol table indexes for the local variables.
+ virtual unsigned int
+ do_set_local_dynsym_indexes(unsigned int) = 0;
+
+ // Set the offset where local dynamic symbol information will be stored.
+ virtual unsigned int
+ do_set_local_dynsym_offset(off_t) = 0;
+
+ // Relocate the input sections and write out the local
+ // symbols--implemented by child class.
+ virtual void
+ do_relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout*, Output_file* of) = 0;
+
+ // Return the vector mapping input sections to output sections.
+ std::vector<Map_to_output>&
+ map_to_output()
+ { return this->map_to_output_; }
+
+ const std::vector<Map_to_output>&
+ map_to_output() const
+ { return this->map_to_output_; }
+
+ // Record that we must wait for the output sections to be written
+ // before applying relocations.
+ void
+ set_relocs_must_follow_section_writes()
+ { this->relocs_must_follow_section_writes_ = true; }
+
+ private:
+ // Mapping from input sections to output section.
+ std::vector<Map_to_output> map_to_output_;
+ // Mappings for merge sections. This is managed by the code in the
+ // Merge_map class.
+ Object_merge_map* object_merge_map_;
+ // Whether we need to wait for output sections to be written before
+ // we can apply relocations.
+ bool relocs_must_follow_section_writes_;
+};
+
+// Implement Object::output_section inline for efficiency.
+inline Output_section*
+Relobj::output_section(unsigned int shndx, section_offset_type* poff) const
+{
+ gold_assert(shndx < this->map_to_output_.size());
+ const Map_to_output& mo(this->map_to_output_[shndx]);
+ *poff = mo.offset;
+ return mo.output_section;
+}
+
+// This POD class is holds the value of a symbol. This is used for
+// local symbols, and for all symbols during relocation processing.
+// For special sections, such as SHF_MERGE sections, this calls a
+// function to get the final symbol value.
+
+template<int size>
+class Symbol_value
+{
+ public:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
+
+ Symbol_value()
+ : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
+ is_section_symbol_(false), is_tls_symbol_(false),
+ needs_output_address_(false), value_(0)
+ { }
+
+ // Get the value of this symbol. OBJECT is the object in which this
+ // symbol is defined, and ADDEND is an addend to add to the value.
+ template<bool big_endian>
+ Value
+ value(const Sized_relobj<size, big_endian>* object, Value addend) const
+ {
+ if (!this->needs_output_address_)
+ return this->value_ + addend;
+ return object->local_value(this->input_shndx_, this->value_,
+ this->is_section_symbol_, addend);
+ }
+
+ // Set the value of this symbol in the output symbol table.
+ void
+ set_output_value(Value value)
+ {
+ this->value_ = value;
+ this->needs_output_address_ = false;
+ }
+
+ // Set the value of the symbol from the input file. This value
+ // will usually be replaced during finalization with the output
+ // value, but if the symbol is mapped to an output section which
+ // requires special handling to determine the output value, we
+ // leave the input value in place until later. This is used for
+ // SHF_MERGE sections.
+ void
+ set_input_value(Value value)
+ {
+ this->value_ = value;
+ this->needs_output_address_ = true;
+ }
+
+ // Return the input value.
+ Value
+ input_value() const
+ {
+ gold_assert(this->needs_output_address_);
+ return this->value_;
+ }
+
+ // Return whether this symbol should go into the output symbol
+ // table.
+ bool
+ needs_output_symtab_entry() const
+ { return this->output_symtab_index_ != -1U; }
+
+ // Return the index in the output symbol table.
+ unsigned int
+ output_symtab_index() const
+ {
+ gold_assert(this->output_symtab_index_ != 0);
+ return this->output_symtab_index_;
+ }
+
+ // Set the index in the output symbol table.
+ void
+ set_output_symtab_index(unsigned int i)
+ {
+ gold_assert(this->output_symtab_index_ == 0);
+ this->output_symtab_index_ = i;
+ }
+
+ // Record that this symbol should not go into the output symbol
+ // table.
+ void
+ set_no_output_symtab_entry()
+ {
+ gold_assert(this->output_symtab_index_ == 0);
+ this->output_symtab_index_ = -1U;
+ }
+
+ // Set the index in the output dynamic symbol table.
+ void
+ set_needs_output_dynsym_entry()
+ {
+ this->output_dynsym_index_ = 0;
+ }
+
+ // Return whether this symbol should go into the output symbol
+ // table.
+ bool
+ needs_output_dynsym_entry() const
+ {
+ return this->output_dynsym_index_ != -1U;
+ }
+
+ // Record that this symbol should go into the dynamic symbol table.
+ void
+ set_output_dynsym_index(unsigned int i)
+ {
+ gold_assert(this->output_dynsym_index_ == 0);
+ this->output_dynsym_index_ = i;
+ }
+
+ // Return the index in the output dynamic symbol table.
+ unsigned int
+ output_dynsym_index() const
+ {
+ gold_assert(this->output_dynsym_index_ != 0);
+ return this->output_dynsym_index_;
+ }
+
+ // Set the index of the input section in the input file.
+ void
+ set_input_shndx(unsigned int i)
+ {
+ this->input_shndx_ = i;
+ // input_shndx_ field is a bitfield, so make sure that the value
+ // fits.
+ gold_assert(this->input_shndx_ == i);
+ }
+
+ // Return the index of the input section in the input file.
+ unsigned int
+ input_shndx() const
+ { return this->input_shndx_; }
+
+ // Record that this is a section symbol.
+ void
+ set_is_section_symbol()
+ { this->is_section_symbol_ = true; }
+
+ // Record that this is a TLS symbol.
+ void
+ set_is_tls_symbol()
+ { this->is_tls_symbol_ = true; }
+
+ // Return TRUE if this is a TLS symbol.
+ bool
+ is_tls_symbol() const
+ { return this->is_tls_symbol_; }
+
+ private:
+ // The index of this local symbol in the output symbol table. This
+ // will be -1 if the symbol should not go into the symbol table.
+ unsigned int output_symtab_index_;
+ // The index of this local symbol in the dynamic symbol table. This
+ // will be -1 if the symbol should not go into the symbol table.
+ unsigned int output_dynsym_index_;
+ // The section index in the input file in which this symbol is
+ // defined.
+ unsigned int input_shndx_ : 29;
+ // Whether this is a STT_SECTION symbol.
+ bool is_section_symbol_ : 1;
+ // Whether this is a STT_TLS symbol.
+ bool is_tls_symbol_ : 1;
+ // Whether getting the value of this symbol requires calling an
+ // Output_section method. For example, this will be true of a
+ // symbol in a SHF_MERGE section.
+ bool needs_output_address_ : 1;
+ // The value of the symbol. If !needs_output_address_, this is the
+ // value in the output file. If needs_output_address_, this is the
+ // value in the input file.
+ Value value_;
+};
// A regular object file. This is size and endian specific.
template<int size, bool big_endian>
-class Sized_object : public Object
+class Sized_relobj : public Relobj
{
public:
- Sized_object(const std::string& name, Input_file* input_file, off_t offset,
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef std::vector<Symbol*> Symbols;
+ typedef std::vector<Symbol_value<size> > Local_values;
+
+ Sized_relobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>&);
- ~Sized_object();
+ ~Sized_relobj();
// Set up the object file based on the ELF header.
void
setup(const typename elfcpp::Ehdr<size, big_endian>&);
- // Read the symbols.
- Read_symbols_data
- do_read_symbols();
+ // If SYM is the index of a global symbol in the object file's
+ // symbol table, return the Symbol object. Otherwise, return NULL.
+ Symbol*
+ global_symbol(unsigned int sym) const
+ {
+ if (sym >= this->local_symbol_count_)
+ {
+ gold_assert(sym - this->local_symbol_count_ < this->symbols_.size());
+ return this->symbols_[sym - this->local_symbol_count_];
+ }
+ return NULL;
+ }
- // Add the symbols to the symbol table.
- void
- do_add_symbols(Symbol_table*, Read_symbols_data);
+ // Return the section index of symbol SYM. Set *VALUE to its value
+ // in the object file. Note that for a symbol which is not defined
+ // in this object file, this will set *VALUE to 0 and return
+ // SHN_UNDEF; it will not return the final value of the symbol in
+ // the link.
+ unsigned int
+ symbol_section_and_value(unsigned int sym, Address* value);
- // Lay out the input sections.
- void
- do_layout(Layout*);
+ // Return a pointer to the Symbol_value structure which holds the
+ // value of a local symbol.
+ const Symbol_value<size>*
+ local_symbol(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return &this->local_values_[sym];
+ }
- // Finalize the local symbols.
- off_t
- do_finalize_local_symbols(off_t, Stringpool*);
+ // Return the index of local symbol SYM in the ordinary symbol
+ // table. A value of -1U means that the symbol is not being output.
+ unsigned int
+ symtab_index(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return this->local_values_[sym].output_symtab_index();
+ }
+
+ // Return the index of local symbol SYM in the dynamic symbol
+ // table. A value of -1U means that the symbol is not being output.
+ unsigned int
+ dynsym_index(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return this->local_values_[sym].output_dynsym_index();
+ }
// Return the appropriate Sized_target structure.
Sized_target<size, big_endian>*
sized_target()
{
-#ifdef HAVE_MEMBER_TEMPLATE_SPECIFICATIONS
- return this->Object::sized_target<size, big_endian>();
-#else
- return static_cast<Sized_target<size, big_endian>*>(this->target());
-#endif
+ return this->Object::sized_target
+ SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
+ SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
}
- private:
- // This object may not be copied.
- Sized_object(const Sized_object&);
- Sized_object& operator=(const Sized_object&);
+ // Return the value of the local symbol symndx.
+ Address
+ local_symbol_value(unsigned int symndx) const;
+
+ // Return the value of a local symbol defined in input section
+ // SHNDX, with value VALUE, adding addend ADDEND. IS_SECTION_SYMBOL
+ // indicates whether the symbol is a section symbol. This handles
+ // SHF_MERGE sections.
+ Address
+ local_value(unsigned int shndx, Address value, bool is_section_symbol,
+ Address addend) const;
+
+ void
+ set_needs_output_dynsym_entry(unsigned int sym)
+ {
+ gold_assert(sym < this->local_values_.size());
+ this->local_values_[sym].set_needs_output_dynsym_entry();
+ }
+
+ // Return whether the local symbol SYMNDX has a GOT offset.
+ // For TLS symbols, the GOT entry will hold its tp-relative offset.
+ bool
+ local_has_got_offset(unsigned int symndx) const
+ {
+ return (this->local_got_offsets_.find(symndx)
+ != this->local_got_offsets_.end());
+ }
+ // Return the GOT offset of the local symbol SYMNDX.
+ unsigned int
+ local_got_offset(unsigned int symndx) const
+ {
+ Local_got_offsets::const_iterator p =
+ this->local_got_offsets_.find(symndx);
+ gold_assert(p != this->local_got_offsets_.end());
+ return p->second;
+ }
+
+ // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
+ void
+ set_local_got_offset(unsigned int symndx, unsigned int got_offset)
+ {
+ std::pair<Local_got_offsets::iterator, bool> ins =
+ this->local_got_offsets_.insert(std::make_pair(symndx, got_offset));
+ gold_assert(ins.second);
+ }
+
+ // Return whether the local TLS symbol SYMNDX has a GOT offset.
+ // The GOT entry at this offset will contain a module index. If
+ // NEED_PAIR is true, a second entry immediately following the first
+ // will contain the dtv-relative offset.
+ bool
+ local_has_tls_got_offset(unsigned int symndx, bool need_pair) const
+ {
+ typename Local_tls_got_offsets::const_iterator p =
+ this->local_tls_got_offsets_.find(symndx);
+ if (p == this->local_tls_got_offsets_.end()
+ || (need_pair && !p->second.have_pair_))
+ return false;
+ return true;
+ }
+
+ // Return the offset of the GOT entry for the local TLS symbol SYMNDX.
+ // If NEED_PAIR is true, we need the offset of a pair of GOT entries;
+ // otherwise we need the offset of the GOT entry for the module index.
+ unsigned int
+ local_tls_got_offset(unsigned int symndx, bool need_pair) const
+ {
+ typename Local_tls_got_offsets::const_iterator p =
+ this->local_tls_got_offsets_.find(symndx);
+ gold_assert(p != this->local_tls_got_offsets_.end());
+ gold_assert(!need_pair || p->second.have_pair_);
+ return p->second.got_offset_;
+ }
+
+ // Set the offset of the GOT entry for the local TLS symbol SYMNDX
+ // to GOT_OFFSET. If HAVE_PAIR is true, we have a pair of GOT entries;
+ // otherwise, we have just a single entry for the module index.
+ void
+ set_local_tls_got_offset(unsigned int symndx, unsigned int got_offset,
+ bool have_pair)
+ {
+ typename Local_tls_got_offsets::iterator p =
+ this->local_tls_got_offsets_.find(symndx);
+ if (p != this->local_tls_got_offsets_.end())
+ {
+ // An entry already existed for this symbol. This can happen
+ // if we see a relocation asking for the module index before
+ // a relocation asking for the pair. In that case, the original
+ // GOT entry will remain, but won't get used by any further
+ // relocations.
+ p->second.got_offset_ = got_offset;
+ gold_assert(have_pair);
+ p->second.have_pair_ = true;
+ }
+ else
+ {
+ std::pair<typename Local_tls_got_offsets::iterator, bool> ins =
+ this->local_tls_got_offsets_.insert(
+ std::make_pair(symndx, Tls_got_entry(got_offset, have_pair)));
+ gold_assert(ins.second);
+ }
+ }
+
+ // Return the name of the symbol that spans the given offset in the
+ // specified section in this object. This is used only for error
+ // messages and is not particularly efficient.
+ bool
+ get_symbol_location_info(unsigned int shndx, off_t offset,
+ Symbol_location_info* info);
+
+ protected:
+ // Read the symbols.
+ void
+ do_read_symbols(Read_symbols_data*);
+
+ // Return the number of local symbols.
+ unsigned int
+ do_local_symbol_count() const
+ { return this->local_symbol_count_; }
+
+ // Lay out the input sections.
+ void
+ do_layout(Symbol_table*, Layout*, Read_symbols_data*);
+
+ // Add the symbols to the symbol table.
+ void
+ do_add_symbols(Symbol_table*, Read_symbols_data*);
+
+ // Read the relocs.
+ void
+ do_read_relocs(Read_relocs_data*);
+
+ // Scan the relocs and adjust the symbol table.
+ void
+ do_scan_relocs(const General_options&, Symbol_table*, Layout*,
+ Read_relocs_data*);
+
+ // Count the local symbols.
+ void
+ do_count_local_symbols(Stringpool_template<char>*,
+ Stringpool_template<char>*);
+
+ // Finalize the local symbols.
+ unsigned int
+ do_finalize_local_symbols(unsigned int, off_t);
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ do_set_local_dynsym_indexes(unsigned int);
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ do_set_local_dynsym_offset(off_t);
+
+ // Relocate the input sections and write out the local symbols.
+ void
+ do_relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout*, Output_file* of);
+
+ // Get the name of a section.
+ std::string
+ do_section_name(unsigned int shndx)
+ { return this->elf_file_.section_name(shndx); }
+
+ // Return the location of the contents of a section.
+ Object::Location
+ do_section_contents(unsigned int shndx)
+ { return this->elf_file_.section_contents(shndx); }
+
+ // Return section flags.
+ uint64_t
+ do_section_flags(unsigned int shndx)
+ { return this->elf_file_.section_flags(shndx); }
+
+ // Return section type.
+ unsigned int
+ do_section_type(unsigned int shndx)
+ { return this->elf_file_.section_type(shndx); }
+
+ // Return the section link field.
+ unsigned int
+ do_section_link(unsigned int shndx)
+ { return this->elf_file_.section_link(shndx); }
+
+ // Return the section info field.
+ unsigned int
+ do_section_info(unsigned int shndx)
+ { return this->elf_file_.section_info(shndx); }
+
+ private:
// For convenience.
- typedef Sized_object<size, big_endian> This;
+ typedef Sized_relobj<size, big_endian> This;
static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
typedef elfcpp::Shdr<size, big_endian> Shdr;
- // Read the section header for section SHNUM.
- const unsigned char*
- section_header(unsigned int shnum);
+ // Find the SHT_SYMTAB section, given the section headers.
+ void
+ find_symtab(const unsigned char* pshdrs);
+
+ // Return whether SHDR has the right flags for a GNU style exception
+ // frame section.
+ bool
+ check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const;
+
+ // Return whether there is a section named .eh_frame which might be
+ // a GNU style exception frame section.
+ bool
+ find_eh_frame(const unsigned char* pshdrs, const char* names,
+ section_size_type names_size) const;
// Whether to include a section group in the link.
bool
include_linkonce_section(Layout*, const char*,
const elfcpp::Shdr<size, big_endian>&);
- // ELF file header e_flags field.
- unsigned int flags_;
- // File offset of section header table.
- off_t shoff_;
- // Offset of SHT_STRTAB section holding section names.
- unsigned int shstrndx_;
+ // Views and sizes when relocating.
+ struct View_size
+ {
+ unsigned char* view;
+ typename elfcpp::Elf_types<size>::Elf_Addr address;
+ off_t offset;
+ section_size_type view_size;
+ bool is_input_output_view;
+ bool is_postprocessing_view;
+ };
+
+ typedef std::vector<View_size> Views;
+
+ // Write section data to the output file. Record the views and
+ // sizes in VIEWS for use when relocating.
+ void
+ write_sections(const unsigned char* pshdrs, Output_file*, Views*) const;
+
+ // Relocate the sections in the output file.
+ void
+ relocate_sections(const General_options& options, const Symbol_table*,
+ const Layout*, const unsigned char* pshdrs, Views*);
+
+ // Write out the local symbols.
+ void
+ write_local_symbols(Output_file*,
+ const Stringpool_template<char>*,
+ const Stringpool_template<char>*);
+
+ // The GOT offsets of local symbols. This map also stores GOT offsets
+ // for tp-relative offsets for TLS symbols.
+ typedef Unordered_map<unsigned int, unsigned int> Local_got_offsets;
+
+ // The TLS GOT offsets of local symbols. The map stores the offsets
+ // for either a single GOT entry that holds the module index of a TLS
+ // symbol, or a pair of GOT entries containing the module index and
+ // dtv-relative offset.
+ struct Tls_got_entry
+ {
+ Tls_got_entry(int got_offset, bool have_pair)
+ : got_offset_(got_offset),
+ have_pair_(have_pair)
+ { }
+ int got_offset_;
+ bool have_pair_;
+ };
+ typedef Unordered_map<unsigned int, Tls_got_entry> Local_tls_got_offsets;
+
+ // General access to the ELF file.
+ elfcpp::Elf_file<size, big_endian, Object> elf_file_;
// Index of SHT_SYMTAB section.
- unsigned int symtab_shnum_;
+ unsigned int symtab_shndx_;
+ // The number of local symbols.
+ unsigned int local_symbol_count_;
+ // The number of local symbols which go into the output file.
+ unsigned int output_local_symbol_count_;
+ // The number of local symbols which go into the output file's dynamic
+ // symbol table.
+ unsigned int output_local_dynsym_count_;
// The entries in the symbol table for the external symbols.
- Symbol** symbols_;
+ Symbols symbols_;
// File offset for local symbols.
off_t local_symbol_offset_;
+ // File offset for local dynamic symbols.
+ off_t local_dynsym_offset_;
+ // Values of local symbols.
+ Local_values local_values_;
+ // GOT offsets for local non-TLS symbols, and tp-relative offsets
+ // for TLS symbols, indexed by symbol number.
+ Local_got_offsets local_got_offsets_;
+ // GOT offsets for local TLS symbols, indexed by symbol number
+ // and GOT entry type.
+ Local_tls_got_offsets local_tls_got_offsets_;
+ // Whether this object has a GNU style .eh_frame section.
+ bool has_eh_frame_;
};
// A class to manage the list of all objects.
{
public:
Input_objects()
- : object_list_(), target_(NULL), any_dynamic_(false)
+ : relobj_list_(), dynobj_list_(), target_(NULL), sonames_(),
+ system_library_directory_()
{ }
- // The type of the list of input objects.
- typedef std::list<Object*> Object_list;
+ // The type of the list of input relocateable objects.
+ typedef std::vector<Relobj*> Relobj_list;
+ typedef Relobj_list::const_iterator Relobj_iterator;
- // Add an object to the list.
- void
+ // The type of the list of input dynamic objects.
+ typedef std::vector<Dynobj*> Dynobj_list;
+ typedef Dynobj_list::const_iterator Dynobj_iterator;
+
+ // Add an object to the list. Return true if all is well, or false
+ // if this object should be ignored.
+ bool
add_object(Object*);
// Get the target we should use for the output file.
target() const
{ return this->target_; }
- // Iterate over all objects.
- Object_list::const_iterator
- begin() const
- { return this->object_list_.begin(); }
+ // For each dynamic object, check whether we've seen all of its
+ // explicit dependencies.
+ void
+ check_dynamic_dependencies() const;
+
+ // Return whether an object was found in the system library
+ // directory.
+ bool
+ found_in_system_library_directory(const Object*) const;
- Object_list::const_iterator
- end() const
- { return this->object_list_.end(); }
+ // Iterate over all regular objects.
+
+ Relobj_iterator
+ relobj_begin() const
+ { return this->relobj_list_.begin(); }
+
+ Relobj_iterator
+ relobj_end() const
+ { return this->relobj_list_.end(); }
+
+ // Iterate over all dynamic objects.
+
+ Dynobj_iterator
+ dynobj_begin() const
+ { return this->dynobj_list_.begin(); }
+
+ Dynobj_iterator
+ dynobj_end() const
+ { return this->dynobj_list_.end(); }
// Return whether we have seen any dynamic objects.
bool
any_dynamic() const
- { return this->any_dynamic_; }
+ { return !this->dynobj_list_.empty(); }
+
+ // Return the number of input objects.
+ int
+ number_of_input_objects() const
+ { return this->relobj_list_.size() + this->dynobj_list_.size(); }
private:
Input_objects(const Input_objects&);
Input_objects& operator=(const Input_objects&);
- Object_list object_list_;
+ // The list of ordinary objects included in the link.
+ Relobj_list relobj_list_;
+ // The list of dynamic objects included in the link.
+ Dynobj_list dynobj_list_;
+ // The target.
Target* target_;
- bool any_dynamic_;
+ // SONAMEs that we have seen.
+ Unordered_set<std::string> sonames_;
+ // The directory in which we find the libc.so.
+ std::string system_library_directory_;
+};
+
+// Some of the information we pass to the relocation routines. We
+// group this together to avoid passing a dozen different arguments.
+
+template<int size, bool big_endian>
+struct Relocate_info
+{
+ // Command line options.
+ const General_options* options;
+ // Symbol table.
+ const Symbol_table* symtab;
+ // Layout.
+ const Layout* layout;
+ // Object being relocated.
+ Sized_relobj<size, big_endian>* object;
+ // Section index of relocation section.
+ unsigned int reloc_shndx;
+ // Section index of section being relocated.
+ unsigned int data_shndx;
+
+ // Return a string showing the location of a relocation. This is
+ // only used for error messages.
+ std::string
+ location(size_t relnum, off_t reloffset) const;
};
// Return an Object appropriate for the input file. P is BYTES long,
// and holds the ELF header.
-extern Object* make_elf_object(const std::string& name, Input_file*,
- off_t offset, const unsigned char* p,
- off_t bytes);
+extern Object*
+make_elf_object(const std::string& name, Input_file*,
+ off_t offset, const unsigned char* p,
+ section_offset_type bytes);
} // end namespace gold
projects / binutils-gdb.git / blobdiff