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Diffstat (limited to 'binutils-2.25/gold/output.h')
| -rw-r--r-- | binutils-2.25/gold/output.h | 4866 |
1 files changed, 4866 insertions, 0 deletions
diff --git a/binutils-2.25/gold/output.h b/binutils-2.25/gold/output.h new file mode 100644 index 00000000..574d270c --- /dev/null +++ b/binutils-2.25/gold/output.h @@ -0,0 +1,4866 @@ +// output.h -- manage the output file for gold -*- C++ -*- + +// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2013 +// 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_OUTPUT_H +#define GOLD_OUTPUT_H + +#include <list> +#include <vector> + +#include "elfcpp.h" +#include "mapfile.h" +#include "layout.h" +#include "reloc-types.h" + +namespace gold +{ + +class General_options; +class Object; +class Symbol; +class Output_file; +class Output_merge_base; +class Output_section; +class Relocatable_relocs; +class Target; +template<int size, bool big_endian> +class Sized_target; +template<int size, bool big_endian> +class Sized_relobj; +template<int size, bool big_endian> +class Sized_relobj_file; + +// An abtract class for data which has to go into the output file. + +class Output_data +{ + public: + explicit Output_data() + : address_(0), data_size_(0), offset_(-1), + is_address_valid_(false), is_data_size_valid_(false), + is_offset_valid_(false), is_data_size_fixed_(false), + has_dynamic_reloc_(false) + { } + + virtual + ~Output_data(); + + // Return the address. For allocated sections, this is only valid + // after Layout::finalize is finished. + uint64_t + address() const + { + gold_assert(this->is_address_valid_); + return this->address_; + } + + // Return the size of the data. For allocated sections, this must + // be valid after Layout::finalize calls set_address, but need not + // be valid before then. + off_t + data_size() const + { + gold_assert(this->is_data_size_valid_); + return this->data_size_; + } + + // Get the current data size. + off_t + current_data_size() const + { return this->current_data_size_for_child(); } + + // Return true if data size is fixed. + bool + is_data_size_fixed() const + { return this->is_data_size_fixed_; } + + // Return the file offset. This is only valid after + // Layout::finalize is finished. For some non-allocated sections, + // it may not be valid until near the end of the link. + off_t + offset() const + { + gold_assert(this->is_offset_valid_); + return this->offset_; + } + + // Reset the address, file offset and data size. This essentially + // disables the sanity testing about duplicate and unknown settings. + void + reset_address_and_file_offset() + { + this->is_address_valid_ = false; + this->is_offset_valid_ = false; + if (!this->is_data_size_fixed_) + this->is_data_size_valid_ = false; + this->do_reset_address_and_file_offset(); + } + + // As above, but just for data size. + void + reset_data_size() + { + if (!this->is_data_size_fixed_) + this->is_data_size_valid_ = false; + } + + // Return true if address and file offset already have reset values. In + // other words, calling reset_address_and_file_offset will not change them. + bool + address_and_file_offset_have_reset_values() const + { return this->do_address_and_file_offset_have_reset_values(); } + + // Return the required alignment. + uint64_t + addralign() const + { return this->do_addralign(); } + + // Return whether this has a load address. + bool + has_load_address() const + { return this->do_has_load_address(); } + + // Return the load address. + uint64_t + load_address() const + { return this->do_load_address(); } + + // Return whether this is an Output_section. + bool + is_section() const + { return this->do_is_section(); } + + // Return whether this is an Output_section of the specified type. + bool + is_section_type(elfcpp::Elf_Word stt) const + { return this->do_is_section_type(stt); } + + // Return whether this is an Output_section with the specified flag + // set. + bool + is_section_flag_set(elfcpp::Elf_Xword shf) const + { return this->do_is_section_flag_set(shf); } + + // Return the output section that this goes in, if there is one. + Output_section* + output_section() + { return this->do_output_section(); } + + const Output_section* + output_section() const + { return this->do_output_section(); } + + // Return the output section index, if there is an output section. + unsigned int + out_shndx() const + { return this->do_out_shndx(); } + + // Set the output section index, if this is an output section. + void + set_out_shndx(unsigned int shndx) + { this->do_set_out_shndx(shndx); } + + // Set the address and file offset of this data, and finalize the + // size of the data. This is called during Layout::finalize for + // allocated sections. + void + set_address_and_file_offset(uint64_t addr, off_t off) + { + this->set_address(addr); + this->set_file_offset(off); + this->finalize_data_size(); + } + + // Set the address. + void + set_address(uint64_t addr) + { + gold_assert(!this->is_address_valid_); + this->address_ = addr; + this->is_address_valid_ = true; + } + + // Set the file offset. + void + set_file_offset(off_t off) + { + gold_assert(!this->is_offset_valid_); + this->offset_ = off; + this->is_offset_valid_ = true; + } + + // Update the data size without finalizing it. + void + pre_finalize_data_size() + { + if (!this->is_data_size_valid_) + { + // Tell the child class to update the data size. + this->update_data_size(); + } + } + + // Finalize the data size. + void + finalize_data_size() + { + if (!this->is_data_size_valid_) + { + // Tell the child class to set the data size. + this->set_final_data_size(); + gold_assert(this->is_data_size_valid_); + } + } + + // Set the TLS offset. Called only for SHT_TLS sections. + void + set_tls_offset(uint64_t tls_base) + { this->do_set_tls_offset(tls_base); } + + // Return the TLS offset, relative to the base of the TLS segment. + // Valid only for SHT_TLS sections. + uint64_t + tls_offset() const + { return this->do_tls_offset(); } + + // Write the data to the output file. This is called after + // Layout::finalize is complete. + void + write(Output_file* file) + { this->do_write(file); } + + // This is called by Layout::finalize to note that the sizes of + // allocated sections must now be fixed. + static void + layout_complete() + { Output_data::allocated_sizes_are_fixed = true; } + + // Used to check that layout has been done. + static bool + is_layout_complete() + { return Output_data::allocated_sizes_are_fixed; } + + // Note that a dynamic reloc has been applied to this data. + void + add_dynamic_reloc() + { this->has_dynamic_reloc_ = true; } + + // Return whether a dynamic reloc has been applied. + bool + has_dynamic_reloc() const + { return this->has_dynamic_reloc_; } + + // Whether the address is valid. + bool + is_address_valid() const + { return this->is_address_valid_; } + + // Whether the file offset is valid. + bool + is_offset_valid() const + { return this->is_offset_valid_; } + + // Whether the data size is valid. + bool + is_data_size_valid() const + { return this->is_data_size_valid_; } + + // Print information to the map file. + void + print_to_mapfile(Mapfile* mapfile) const + { return this->do_print_to_mapfile(mapfile); } + + protected: + // Functions that child classes may or in some cases must implement. + + // Write the data to the output file. + virtual void + do_write(Output_file*) = 0; + + // Return the required alignment. + virtual uint64_t + do_addralign() const = 0; + + // Return whether this has a load address. + virtual bool + do_has_load_address() const + { return false; } + + // Return the load address. + virtual uint64_t + do_load_address() const + { gold_unreachable(); } + + // Return whether this is an Output_section. + virtual bool + do_is_section() const + { return false; } + + // Return whether this is an Output_section of the specified type. + // This only needs to be implement by Output_section. + virtual bool + do_is_section_type(elfcpp::Elf_Word) const + { return false; } + + // Return whether this is an Output_section with the specific flag + // set. This only needs to be implemented by Output_section. + virtual bool + do_is_section_flag_set(elfcpp::Elf_Xword) const + { return false; } + + // Return the output section, if there is one. + virtual Output_section* + do_output_section() + { return NULL; } + + virtual const Output_section* + do_output_section() const + { return NULL; } + + // Return the output section index, if there is an output section. + virtual unsigned int + do_out_shndx() const + { gold_unreachable(); } + + // Set the output section index, if this is an output section. + virtual void + do_set_out_shndx(unsigned int) + { gold_unreachable(); } + + // This is a hook for derived classes to set the preliminary data size. + // This is called by pre_finalize_data_size, normally called during + // Layout::finalize, before the section address is set, and is used + // during an incremental update, when we need to know the size of a + // section before allocating space in the output file. For classes + // where the current data size is up to date, this default version of + // the method can be inherited. + virtual void + update_data_size() + { } + + // This is a hook for derived classes to set the data size. This is + // called by finalize_data_size, normally called during + // Layout::finalize, when the section address is set. + virtual void + set_final_data_size() + { gold_unreachable(); } + + // A hook for resetting the address and file offset. + virtual void + do_reset_address_and_file_offset() + { } + + // Return true if address and file offset already have reset values. In + // other words, calling reset_address_and_file_offset will not change them. + // A child class overriding do_reset_address_and_file_offset may need to + // also override this. + virtual bool + do_address_and_file_offset_have_reset_values() const + { return !this->is_address_valid_ && !this->is_offset_valid_; } + + // Set the TLS offset. Called only for SHT_TLS sections. + virtual void + do_set_tls_offset(uint64_t) + { gold_unreachable(); } + + // Return the TLS offset, relative to the base of the TLS segment. + // Valid only for SHT_TLS sections. + virtual uint64_t + do_tls_offset() const + { gold_unreachable(); } + + // Print to the map file. This only needs to be implemented by + // classes which may appear in a PT_LOAD segment. + virtual void + do_print_to_mapfile(Mapfile*) const + { gold_unreachable(); } + + // Functions that child classes may call. + + // Reset the address. The Output_section class needs this when an + // SHF_ALLOC input section is added to an output section which was + // formerly not SHF_ALLOC. + void + mark_address_invalid() + { this->is_address_valid_ = false; } + + // Set the size of the data. + void + set_data_size(off_t data_size) + { + gold_assert(!this->is_data_size_valid_ + && !this->is_data_size_fixed_); + this->data_size_ = data_size; + this->is_data_size_valid_ = true; + } + + // Fix the data size. Once it is fixed, it cannot be changed + // and the data size remains always valid. + void + fix_data_size() + { + gold_assert(this->is_data_size_valid_); + this->is_data_size_fixed_ = true; + } + + // Get the current data size--this is for the convenience of + // sections which build up their size over time. + off_t + current_data_size_for_child() const + { return this->data_size_; } + + // Set the current data size--this is for the convenience of + // sections which build up their size over time. + void + set_current_data_size_for_child(off_t data_size) + { + gold_assert(!this->is_data_size_valid_); + this->data_size_ = data_size; + } + + // Return default alignment for the target size. + static uint64_t + default_alignment(); + + // Return default alignment for a specified size--32 or 64. + static uint64_t + default_alignment_for_size(int size); + + private: + Output_data(const Output_data&); + Output_data& operator=(const Output_data&); + + // This is used for verification, to make sure that we don't try to + // change any sizes of allocated sections after we set the section + // addresses. + static bool allocated_sizes_are_fixed; + + // Memory address in output file. + uint64_t address_; + // Size of data in output file. + off_t data_size_; + // File offset of contents in output file. + off_t offset_; + // Whether address_ is valid. + bool is_address_valid_ : 1; + // Whether data_size_ is valid. + bool is_data_size_valid_ : 1; + // Whether offset_ is valid. + bool is_offset_valid_ : 1; + // Whether data size is fixed. + bool is_data_size_fixed_ : 1; + // Whether any dynamic relocs have been applied to this section. + bool has_dynamic_reloc_ : 1; +}; + +// Output the section headers. + +class Output_section_headers : public Output_data +{ + public: + Output_section_headers(const Layout*, + const Layout::Segment_list*, + const Layout::Section_list*, + const Layout::Section_list*, + const Stringpool*, + const Output_section*); + + protected: + // Write the data to the file. + void + do_write(Output_file*); + + // Return the required alignment. + uint64_t + do_addralign() const + { return Output_data::default_alignment(); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** section headers")); } + + // Update the data size. + void + update_data_size() + { this->set_data_size(this->do_size()); } + + // Set final data size. + void + set_final_data_size() + { this->set_data_size(this->do_size()); } + + private: + // Write the data to the file with the right size and endianness. + template<int size, bool big_endian> + void + do_sized_write(Output_file*); + + // Compute data size. + off_t + do_size() const; + + const Layout* layout_; + const Layout::Segment_list* segment_list_; + const Layout::Section_list* section_list_; + const Layout::Section_list* unattached_section_list_; + const Stringpool* secnamepool_; + const Output_section* shstrtab_section_; +}; + +// Output the segment headers. + +class Output_segment_headers : public Output_data +{ + public: + Output_segment_headers(const Layout::Segment_list& segment_list); + + protected: + // Write the data to the file. + void + do_write(Output_file*); + + // Return the required alignment. + uint64_t + do_addralign() const + { return Output_data::default_alignment(); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** segment headers")); } + + // Set final data size. + void + set_final_data_size() + { this->set_data_size(this->do_size()); } + + private: + // Write the data to the file with the right size and endianness. + template<int size, bool big_endian> + void + do_sized_write(Output_file*); + + // Compute the current size. + off_t + do_size() const; + + const Layout::Segment_list& segment_list_; +}; + +// Output the ELF file header. + +class Output_file_header : public Output_data +{ + public: + Output_file_header(Target*, + const Symbol_table*, + const Output_segment_headers*); + + // Add information about the section headers. We lay out the ELF + // file header before we create the section headers. + void set_section_info(const Output_section_headers*, + const Output_section* shstrtab); + + protected: + // Write the data to the file. + void + do_write(Output_file*); + + // Return the required alignment. + uint64_t + do_addralign() const + { return Output_data::default_alignment(); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** file header")); } + + // Set final data size. + void + set_final_data_size(void) + { this->set_data_size(this->do_size()); } + + private: + // Write the data to the file with the right size and endianness. + template<int size, bool big_endian> + void + do_sized_write(Output_file*); + + // Return the value to use for the entry address. + template<int size> + typename elfcpp::Elf_types<size>::Elf_Addr + entry(); + + // Compute the current data size. + off_t + do_size() const; + + Target* target_; + const Symbol_table* symtab_; + const Output_segment_headers* segment_header_; + const Output_section_headers* section_header_; + const Output_section* shstrtab_; +}; + +// Output sections are mainly comprised of input sections. However, +// there are cases where we have data to write out which is not in an +// input section. Output_section_data is used in such cases. This is +// an abstract base class. + +class Output_section_data : public Output_data +{ + public: + Output_section_data(off_t data_size, uint64_t addralign, + bool is_data_size_fixed) + : Output_data(), output_section_(NULL), addralign_(addralign) + { + this->set_data_size(data_size); + if (is_data_size_fixed) + this->fix_data_size(); + } + + Output_section_data(uint64_t addralign) + : Output_data(), output_section_(NULL), addralign_(addralign) + { } + + // Return the output section. + Output_section* + output_section() + { return this->output_section_; } + + const Output_section* + output_section() const + { return this->output_section_; } + + // Record the output section. + void + set_output_section(Output_section* os); + + // Add an input section, for SHF_MERGE sections. This returns true + // if the section was handled. + bool + add_input_section(Relobj* object, unsigned int shndx) + { return this->do_add_input_section(object, shndx); } + + // Given an input OBJECT, an input section index SHNDX within that + // object, and an OFFSET relative to the start of that input + // section, return whether or not the corresponding offset within + // the output section is known. If this function returns true, it + // sets *POUTPUT to the output offset. The value -1 indicates that + // this input offset is being discarded. + bool + output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset, + section_offset_type* poutput) const + { return this->do_output_offset(object, shndx, offset, poutput); } + + // Return whether this is the merge section for the input section + // SHNDX in OBJECT. This should return true when output_offset + // would return true for some values of OFFSET. + bool + is_merge_section_for(const Relobj* object, unsigned int shndx) const + { return this->do_is_merge_section_for(object, shndx); } + + // Write the contents to a buffer. This is used for sections which + // require postprocessing, such as compression. + void + write_to_buffer(unsigned char* buffer) + { this->do_write_to_buffer(buffer); } + + // Print merge stats to stderr. This should only be called for + // SHF_MERGE sections. + void + print_merge_stats(const char* section_name) + { this->do_print_merge_stats(section_name); } + + protected: + // The child class must implement do_write. + + // The child class may implement specific adjustments to the output + // section. + virtual void + do_adjust_output_section(Output_section*) + { } + + // May be implemented by child class. Return true if the section + // was handled. + virtual bool + do_add_input_section(Relobj*, unsigned int) + { gold_unreachable(); } + + // The child class may implement output_offset. + virtual bool + do_output_offset(const Relobj*, unsigned int, section_offset_type, + section_offset_type*) const + { return false; } + + // The child class may implement is_merge_section_for. + virtual bool + do_is_merge_section_for(const Relobj*, unsigned int) const + { return false; } + + // The child class may implement write_to_buffer. Most child + // classes can not appear in a compressed section, and they do not + // implement this. + virtual void + do_write_to_buffer(unsigned char*) + { gold_unreachable(); } + + // Print merge statistics. + virtual void + do_print_merge_stats(const char*) + { gold_unreachable(); } + + // Return the required alignment. + uint64_t + do_addralign() const + { return this->addralign_; } + + // Return the output section. + Output_section* + do_output_section() + { return this->output_section_; } + + const Output_section* + do_output_section() const + { return this->output_section_; } + + // Return the section index of the output section. + unsigned int + do_out_shndx() const; + + // Set the alignment. + void + set_addralign(uint64_t addralign); + + private: + // The output section for this section. + Output_section* output_section_; + // The required alignment. + uint64_t addralign_; +}; + +// Some Output_section_data classes build up their data step by step, +// rather than all at once. This class provides an interface for +// them. + +class Output_section_data_build : public Output_section_data +{ + public: + Output_section_data_build(uint64_t addralign) + : Output_section_data(addralign) + { } + + Output_section_data_build(off_t data_size, uint64_t addralign) + : Output_section_data(data_size, addralign, false) + { } + + // Set the current data size. + void + set_current_data_size(off_t data_size) + { this->set_current_data_size_for_child(data_size); } + + protected: + // Set the final data size. + virtual void + set_final_data_size() + { this->set_data_size(this->current_data_size_for_child()); } +}; + +// A simple case of Output_data in which we have constant data to +// output. + +class Output_data_const : public Output_section_data +{ + public: + Output_data_const(const std::string& data, uint64_t addralign) + : Output_section_data(data.size(), addralign, true), data_(data) + { } + + Output_data_const(const char* p, off_t len, uint64_t addralign) + : Output_section_data(len, addralign, true), data_(p, len) + { } + + Output_data_const(const unsigned char* p, off_t len, uint64_t addralign) + : Output_section_data(len, addralign, true), + data_(reinterpret_cast<const char*>(p), len) + { } + + protected: + // Write the data to the output file. + void + do_write(Output_file*); + + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char* buffer) + { memcpy(buffer, this->data_.data(), this->data_.size()); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** fill")); } + + private: + std::string data_; +}; + +// Another version of Output_data with constant data, in which the +// buffer is allocated by the caller. + +class Output_data_const_buffer : public Output_section_data +{ + public: + Output_data_const_buffer(const unsigned char* p, off_t len, + uint64_t addralign, const char* map_name) + : Output_section_data(len, addralign, true), + p_(p), map_name_(map_name) + { } + + protected: + // Write the data the output file. + void + do_write(Output_file*); + + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char* buffer) + { memcpy(buffer, this->p_, this->data_size()); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _(this->map_name_)); } + + private: + // The data to output. + const unsigned char* p_; + // Name to use in a map file. Maps are a rarely used feature, but + // the space usage is minor as aren't very many of these objects. + const char* map_name_; +}; + +// A place holder for a fixed amount of data written out via some +// other mechanism. + +class Output_data_fixed_space : public Output_section_data +{ + public: + Output_data_fixed_space(off_t data_size, uint64_t addralign, + const char* map_name) + : Output_section_data(data_size, addralign, true), + map_name_(map_name) + { } + + protected: + // Write out the data--the actual data must be written out + // elsewhere. + void + do_write(Output_file*) + { } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _(this->map_name_)); } + + private: + // Name to use in a map file. Maps are a rarely used feature, but + // the space usage is minor as aren't very many of these objects. + const char* map_name_; +}; + +// A place holder for variable sized data written out via some other +// mechanism. + +class Output_data_space : public Output_section_data_build +{ + public: + explicit Output_data_space(uint64_t addralign, const char* map_name) + : Output_section_data_build(addralign), + map_name_(map_name) + { } + + explicit Output_data_space(off_t data_size, uint64_t addralign, + const char* map_name) + : Output_section_data_build(data_size, addralign), + map_name_(map_name) + { } + + // Set the alignment. + void + set_space_alignment(uint64_t align) + { this->set_addralign(align); } + + protected: + // Write out the data--the actual data must be written out + // elsewhere. + void + do_write(Output_file*) + { } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _(this->map_name_)); } + + private: + // Name to use in a map file. Maps are a rarely used feature, but + // the space usage is minor as aren't very many of these objects. + const char* map_name_; +}; + +// Fill fixed space with zeroes. This is just like +// Output_data_fixed_space, except that the map name is known. + +class Output_data_zero_fill : public Output_section_data +{ + public: + Output_data_zero_fill(off_t data_size, uint64_t addralign) + : Output_section_data(data_size, addralign, true) + { } + + protected: + // There is no data to write out. + void + do_write(Output_file*) + { } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, "** zero fill"); } +}; + +// A string table which goes into an output section. + +class Output_data_strtab : public Output_section_data +{ + public: + Output_data_strtab(Stringpool* strtab) + : Output_section_data(1), strtab_(strtab) + { } + + protected: + // This is called to update the section size prior to assigning + // the address and file offset. + void + update_data_size() + { this->set_final_data_size(); } + + // This is called to set the address and file offset. Here we make + // sure that the Stringpool is finalized. + void + set_final_data_size(); + + // Write out the data. + void + do_write(Output_file*); + + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char* buffer) + { this->strtab_->write_to_buffer(buffer, this->data_size()); } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** string table")); } + + private: + Stringpool* strtab_; +}; + +// This POD class is used to represent a single reloc in the output +// file. This could be a private class within Output_data_reloc, but +// the templatization is complex enough that I broke it out into a +// separate class. The class is templatized on either elfcpp::SHT_REL +// or elfcpp::SHT_RELA, and also on whether this is a dynamic +// relocation or an ordinary relocation. + +// A relocation can be against a global symbol, a local symbol, a +// local section symbol, an output section, or the undefined symbol at +// index 0. We represent the latter by using a NULL global symbol. + +template<int sh_type, bool dynamic, int size, bool big_endian> +class Output_reloc; + +template<bool dynamic, int size, bool big_endian> +class Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend; + + static const Address invalid_address = static_cast<Address>(0) - 1; + + // An uninitialized entry. We need this because we want to put + // instances of this class into an STL container. + Output_reloc() + : local_sym_index_(INVALID_CODE) + { } + + // We have a bunch of different constructors. They come in pairs + // depending on how the address of the relocation is specified. It + // can either be an offset in an Output_data or an offset in an + // input section. + + // A reloc against a global symbol. + + Output_reloc(Symbol* gsym, unsigned int type, Output_data* od, + Address address, bool is_relative, bool is_symbolless, + bool use_plt_offset); + + Output_reloc(Symbol* gsym, unsigned int type, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, bool is_relative, + bool is_symbolless, bool use_plt_offset); + + // A reloc against a local symbol or local section symbol. + + Output_reloc(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address, bool is_relative, + bool is_symbolless, bool is_section_symbol, + bool use_plt_offset); + + Output_reloc(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + unsigned int shndx, Address address, bool is_relative, + bool is_symbolless, bool is_section_symbol, + bool use_plt_offset); + + // A reloc against the STT_SECTION symbol of an output section. + + Output_reloc(Output_section* os, unsigned int type, Output_data* od, + Address address, bool is_relative); + + Output_reloc(Output_section* os, unsigned int type, + Sized_relobj<size, big_endian>* relobj, unsigned int shndx, + Address address, bool is_relative); + + // An absolute or relative relocation with no symbol. + + Output_reloc(unsigned int type, Output_data* od, Address address, + bool is_relative); + + Output_reloc(unsigned int type, Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, bool is_relative); + + // A target specific relocation. The target will be called to get + // the symbol index, passing ARG. The type and offset will be set + // as for other relocation types. + + Output_reloc(unsigned int type, void* arg, Output_data* od, + Address address); + + Output_reloc(unsigned int type, void* arg, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address); + + // Return the reloc type. + unsigned int + type() const + { return this->type_; } + + // Return whether this is a RELATIVE relocation. + bool + is_relative() const + { return this->is_relative_; } + + // Return whether this is a relocation which should not use + // a symbol, but which obtains its addend from a symbol. + bool + is_symbolless() const + { return this->is_symbolless_; } + + // Return whether this is against a local section symbol. + bool + is_local_section_symbol() const + { + return (this->local_sym_index_ != GSYM_CODE + && this->local_sym_index_ != SECTION_CODE + && this->local_sym_index_ != INVALID_CODE + && this->local_sym_index_ != TARGET_CODE + && this->is_section_symbol_); + } + + // Return whether this is a target specific relocation. + bool + is_target_specific() const + { return this->local_sym_index_ == TARGET_CODE; } + + // Return the argument to pass to the target for a target specific + // relocation. + void* + target_arg() const + { + gold_assert(this->local_sym_index_ == TARGET_CODE); + return this->u1_.arg; + } + + // For a local section symbol, return the offset of the input + // section within the output section. ADDEND is the addend being + // applied to the input section. + Address + local_section_offset(Addend addend) const; + + // Get the value of the symbol referred to by a Rel relocation when + // we are adding the given ADDEND. + Address + symbol_value(Addend addend) const; + + // If this relocation is against an input section, return the + // relocatable object containing the input section. + Sized_relobj<size, big_endian>* + get_relobj() const + { + if (this->shndx_ == INVALID_CODE) + return NULL; + return this->u2_.relobj; + } + + // Write the reloc entry to an output view. + void + write(unsigned char* pov) const; + + // Write the offset and info fields to Write_rel. + template<typename Write_rel> + void write_rel(Write_rel*) const; + + // This is used when sorting dynamic relocs. Return -1 to sort this + // reloc before R2, 0 to sort the same as R2, 1 to sort after R2. + int + compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2) + const; + + // Return whether this reloc should be sorted before the argument + // when sorting dynamic relocs. + bool + sort_before(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& + r2) const + { return this->compare(r2) < 0; } + + private: + // Record that we need a dynamic symbol index. + void + set_needs_dynsym_index(); + + // Return the symbol index. + unsigned int + get_symbol_index() const; + + // Return the output address. + Address + get_address() const; + + // Codes for local_sym_index_. + enum + { + // Global symbol. + GSYM_CODE = -1U, + // Output section. + SECTION_CODE = -2U, + // Target specific. + TARGET_CODE = -3U, + // Invalid uninitialized entry. + INVALID_CODE = -4U + }; + + union + { + // For a local symbol or local section symbol + // (this->local_sym_index_ >= 0), the object. We will never + // generate a relocation against a local symbol in a dynamic + // object; that doesn't make sense. And our callers will always + // be templatized, so we use Sized_relobj here. + Sized_relobj<size, big_endian>* relobj; + // For a global symbol (this->local_sym_index_ == GSYM_CODE, the + // symbol. If this is NULL, it indicates a relocation against the + // undefined 0 symbol. + Symbol* gsym; + // For a relocation against an output section + // (this->local_sym_index_ == SECTION_CODE), the output section. + Output_section* os; + // For a target specific relocation, an argument to pass to the + // target. + void* arg; + } u1_; + union + { + // If this->shndx_ is not INVALID CODE, the object which holds the + // input section being used to specify the reloc address. + Sized_relobj<size, big_endian>* relobj; + // If this->shndx_ is INVALID_CODE, the output data being used to + // specify the reloc address. This may be NULL if the reloc + // address is absolute. + Output_data* od; + } u2_; + // The address offset within the input section or the Output_data. + Address address_; + // This is GSYM_CODE for a global symbol, or SECTION_CODE for a + // relocation against an output section, or TARGET_CODE for a target + // specific relocation, or INVALID_CODE for an uninitialized value. + // Otherwise, for a local symbol (this->is_section_symbol_ is + // false), the local symbol index. For a local section symbol + // (this->is_section_symbol_ is true), the section index in the + // input file. + unsigned int local_sym_index_; + // The reloc type--a processor specific code. + unsigned int type_ : 28; + // True if the relocation is a RELATIVE relocation. + bool is_relative_ : 1; + // True if the relocation is one which should not use + // a symbol, but which obtains its addend from a symbol. + bool is_symbolless_ : 1; + // True if the relocation is against a section symbol. + bool is_section_symbol_ : 1; + // True if the addend should be the PLT offset. + // (Used only for RELA, but stored here for space.) + bool use_plt_offset_ : 1; + // If the reloc address is an input section in an object, the + // section index. This is INVALID_CODE if the reloc address is + // specified in some other way. + unsigned int shndx_; +}; + +// The SHT_RELA version of Output_reloc<>. This is just derived from +// the SHT_REL version of Output_reloc, but it adds an addend. + +template<bool dynamic, int size, bool big_endian> +class Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian> +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend; + + // An uninitialized entry. + Output_reloc() + : rel_() + { } + + // A reloc against a global symbol. + + Output_reloc(Symbol* gsym, unsigned int type, Output_data* od, + Address address, Addend addend, bool is_relative, + bool is_symbolless, bool use_plt_offset) + : rel_(gsym, type, od, address, is_relative, is_symbolless, + use_plt_offset), + addend_(addend) + { } + + Output_reloc(Symbol* gsym, unsigned int type, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend, + bool is_relative, bool is_symbolless, bool use_plt_offset) + : rel_(gsym, type, relobj, shndx, address, is_relative, + is_symbolless, use_plt_offset), addend_(addend) + { } + + // A reloc against a local symbol. + + Output_reloc(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address, + Addend addend, bool is_relative, + bool is_symbolless, bool is_section_symbol, + bool use_plt_offset) + : rel_(relobj, local_sym_index, type, od, address, is_relative, + is_symbolless, is_section_symbol, use_plt_offset), + addend_(addend) + { } + + Output_reloc(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + unsigned int shndx, Address address, + Addend addend, bool is_relative, + bool is_symbolless, bool is_section_symbol, + bool use_plt_offset) + : rel_(relobj, local_sym_index, type, shndx, address, is_relative, + is_symbolless, is_section_symbol, use_plt_offset), + addend_(addend) + { } + + // A reloc against the STT_SECTION symbol of an output section. + + Output_reloc(Output_section* os, unsigned int type, Output_data* od, + Address address, Addend addend, bool is_relative) + : rel_(os, type, od, address, is_relative), addend_(addend) + { } + + Output_reloc(Output_section* os, unsigned int type, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend, + bool is_relative) + : rel_(os, type, relobj, shndx, address, is_relative), addend_(addend) + { } + + // An absolute or relative relocation with no symbol. + + Output_reloc(unsigned int type, Output_data* od, Address address, + Addend addend, bool is_relative) + : rel_(type, od, address, is_relative), addend_(addend) + { } + + Output_reloc(unsigned int type, Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend, + bool is_relative) + : rel_(type, relobj, shndx, address, is_relative), addend_(addend) + { } + + // A target specific relocation. The target will be called to get + // the symbol index and the addend, passing ARG. The type and + // offset will be set as for other relocation types. + + Output_reloc(unsigned int type, void* arg, Output_data* od, + Address address, Addend addend) + : rel_(type, arg, od, address), addend_(addend) + { } + + Output_reloc(unsigned int type, void* arg, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend) + : rel_(type, arg, relobj, shndx, address), addend_(addend) + { } + + // Return whether this is a RELATIVE relocation. + bool + is_relative() const + { return this->rel_.is_relative(); } + + // Return whether this is a relocation which should not use + // a symbol, but which obtains its addend from a symbol. + bool + is_symbolless() const + { return this->rel_.is_symbolless(); } + + // If this relocation is against an input section, return the + // relocatable object containing the input section. + Sized_relobj<size, big_endian>* + get_relobj() const + { return this->rel_.get_relobj(); } + + // Write the reloc entry to an output view. + void + write(unsigned char* pov) const; + + // Return whether this reloc should be sorted before the argument + // when sorting dynamic relocs. + bool + sort_before(const Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>& + r2) const + { + int i = this->rel_.compare(r2.rel_); + if (i < 0) + return true; + else if (i > 0) + return false; + else + return this->addend_ < r2.addend_; + } + + private: + // The basic reloc. + Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> rel_; + // The addend. + Addend addend_; +}; + +// Output_data_reloc_generic is a non-template base class for +// Output_data_reloc_base. This gives the generic code a way to hold +// a pointer to a reloc section. + +class Output_data_reloc_generic : public Output_section_data_build +{ + public: + Output_data_reloc_generic(int size, bool sort_relocs) + : Output_section_data_build(Output_data::default_alignment_for_size(size)), + relative_reloc_count_(0), sort_relocs_(sort_relocs) + { } + + // Return the number of relative relocs in this section. + size_t + relative_reloc_count() const + { return this->relative_reloc_count_; } + + // Whether we should sort the relocs. + bool + sort_relocs() const + { return this->sort_relocs_; } + + // Add a reloc of type TYPE against the global symbol GSYM. The + // relocation applies to the data at offset ADDRESS within OD. + virtual void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + uint64_t address, uint64_t addend) = 0; + + // Add a reloc of type TYPE against the global symbol GSYM. The + // relocation applies to data at offset ADDRESS within section SHNDX + // of object file RELOBJ. OD is the associated output section. + virtual void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + Relobj* relobj, unsigned int shndx, uint64_t address, + uint64_t addend) = 0; + + // Add a reloc of type TYPE against the local symbol LOCAL_SYM_INDEX + // in RELOBJ. The relocation applies to the data at offset ADDRESS + // within OD. + virtual void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, uint64_t address, + uint64_t addend) = 0; + + // Add a reloc of type TYPE against the local symbol LOCAL_SYM_INDEX + // in RELOBJ. The relocation applies to the data at offset ADDRESS + // within section SHNDX of RELOBJ. OD is the associated output + // section. + virtual void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, unsigned int shndx, + uint64_t address, uint64_t addend) = 0; + + // Add a reloc of type TYPE against the STT_SECTION symbol of the + // output section OS. The relocation applies to the data at offset + // ADDRESS within OD. + virtual void + add_output_section_generic(Output_section *os, unsigned int type, + Output_data* od, uint64_t address, + uint64_t addend) = 0; + + // Add a reloc of type TYPE against the STT_SECTION symbol of the + // output section OS. The relocation applies to the data at offset + // ADDRESS within section SHNDX of RELOBJ. OD is the associated + // output section. + virtual void + add_output_section_generic(Output_section* os, unsigned int type, + Output_data* od, Relobj* relobj, + unsigned int shndx, uint64_t address, + uint64_t addend) = 0; + + protected: + // Note that we've added another relative reloc. + void + bump_relative_reloc_count() + { ++this->relative_reloc_count_; } + + private: + // The number of relative relocs added to this section. This is to + // support DT_RELCOUNT. + size_t relative_reloc_count_; + // Whether to sort the relocations when writing them out, to make + // the dynamic linker more efficient. + bool sort_relocs_; +}; + +// Output_data_reloc is used to manage a section containing relocs. +// SH_TYPE is either elfcpp::SHT_REL or elfcpp::SHT_RELA. DYNAMIC +// indicates whether this is a dynamic relocation or a normal +// relocation. Output_data_reloc_base is a base class. +// Output_data_reloc is the real class, which we specialize based on +// the reloc type. + +template<int sh_type, bool dynamic, int size, bool big_endian> +class Output_data_reloc_base : public Output_data_reloc_generic +{ + public: + typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type; + typedef typename Output_reloc_type::Address Address; + static const int reloc_size = + Reloc_types<sh_type, size, big_endian>::reloc_size; + + // Construct the section. + Output_data_reloc_base(bool sort_relocs) + : Output_data_reloc_generic(size, sort_relocs) + { } + + protected: + // Write out the data. + void + do_write(Output_file*); + + // Set the entry size and the link. + void + do_adjust_output_section(Output_section* os); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { + mapfile->print_output_data(this, + (dynamic + ? _("** dynamic relocs") + : _("** relocs"))); + } + + // Add a relocation entry. + void + add(Output_data* od, const Output_reloc_type& reloc) + { + this->relocs_.push_back(reloc); + this->set_current_data_size(this->relocs_.size() * reloc_size); + if (dynamic) + od->add_dynamic_reloc(); + if (reloc.is_relative()) + this->bump_relative_reloc_count(); + Sized_relobj<size, big_endian>* relobj = reloc.get_relobj(); + if (relobj != NULL) + relobj->add_dyn_reloc(this->relocs_.size() - 1); + } + + private: + typedef std::vector<Output_reloc_type> Relocs; + + // The class used to sort the relocations. + struct Sort_relocs_comparison + { + bool + operator()(const Output_reloc_type& r1, const Output_reloc_type& r2) const + { return r1.sort_before(r2); } + }; + + // The relocations in this section. + Relocs relocs_; +}; + +// The class which callers actually create. + +template<int sh_type, bool dynamic, int size, bool big_endian> +class Output_data_reloc; + +// The SHT_REL version of Output_data_reloc. + +template<bool dynamic, int size, bool big_endian> +class Output_data_reloc<elfcpp::SHT_REL, dynamic, size, big_endian> + : public Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian> +{ + private: + typedef Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, + big_endian> Base; + + public: + typedef typename Base::Output_reloc_type Output_reloc_type; + typedef typename Output_reloc_type::Address Address; + + Output_data_reloc(bool sr) + : Output_data_reloc_base<elfcpp::SHT_REL, dynamic, size, big_endian>(sr) + { } + + // Add a reloc against a global symbol. + + void + add_global(Symbol* gsym, unsigned int type, Output_data* od, Address address) + { + this->add(od, Output_reloc_type(gsym, type, od, address, + false, false, false)); + } + + void + add_global(Symbol* gsym, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + false, false, false)); + } + + void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + uint64_t address, uint64_t addend) + { + gold_assert(addend == 0); + this->add(od, Output_reloc_type(gsym, type, od, + convert_types<Address, uint64_t>(address), + false, false, false)); + } + + void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + Relobj* relobj, unsigned int shndx, uint64_t address, + uint64_t addend) + { + gold_assert(addend == 0); + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(gsym, type, sized_relobj, shndx, + convert_types<Address, uint64_t>(address), + false, false, false)); + } + + // Add a RELATIVE reloc against a global symbol. The final relocation + // will not reference the symbol. + + void + add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, + Address address) + { + this->add(od, Output_reloc_type(gsym, type, od, address, true, true, + false)); + } + + void + add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + true, true, false)); + } + + // Add a global relocation which does not use a symbol for the relocation, + // but which gets its addend from a symbol. + + void + add_symbolless_global_addend(Symbol* gsym, unsigned int type, + Output_data* od, Address address) + { + this->add(od, Output_reloc_type(gsym, type, od, address, false, true, + false)); + } + + void + add_symbolless_global_addend(Symbol* gsym, unsigned int type, + Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + false, true, false)); + } + + // Add a reloc against a local symbol. + + void + add_local(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, + address, false, false, false, false)); + } + + void + add_local(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, false, false, false, false)); + } + + void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, uint64_t address, + uint64_t addend) + { + gold_assert(addend == 0); + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian> *>(relobj); + this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, od, + convert_types<Address, uint64_t>(address), + false, false, false, false)); + } + + void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, unsigned int shndx, + uint64_t address, uint64_t addend) + { + gold_assert(addend == 0); + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, shndx, + convert_types<Address, uint64_t>(address), + false, false, false, false)); + } + + // Add a RELATIVE reloc against a local symbol. + + void + add_local_relative(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, + address, true, true, false, false)); + } + + void + add_local_relative(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, true, true, false, false)); + } + + // Add a local relocation which does not use a symbol for the relocation, + // but which gets its addend from a symbol. + + void + add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, + address, false, true, false, false)); + } + + void + add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, + Address address) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, false, true, false, false)); + } + + // Add a reloc against a local section symbol. This will be + // converted into a reloc against the STT_SECTION symbol of the + // output section. + + void + add_local_section(Sized_relobj<size, big_endian>* relobj, + unsigned int input_shndx, unsigned int type, + Output_data* od, Address address) + { + this->add(od, Output_reloc_type(relobj, input_shndx, type, od, + address, false, false, true, false)); + } + + void + add_local_section(Sized_relobj<size, big_endian>* relobj, + unsigned int input_shndx, unsigned int type, + Output_data* od, unsigned int shndx, Address address) + { + this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx, + address, false, false, true, false)); + } + + // A reloc against the STT_SECTION symbol of an output section. + // OS is the Output_section that the relocation refers to; OD is + // the Output_data object being relocated. + + void + add_output_section(Output_section* os, unsigned int type, + Output_data* od, Address address) + { this->add(od, Output_reloc_type(os, type, od, address, false)); } + + void + add_output_section(Output_section* os, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { this->add(od, Output_reloc_type(os, type, relobj, shndx, address, false)); } + + void + add_output_section_generic(Output_section* os, unsigned int type, + Output_data* od, uint64_t address, + uint64_t addend) + { + gold_assert(addend == 0); + this->add(od, Output_reloc_type(os, type, od, + convert_types<Address, uint64_t>(address), + false)); + } + + void + add_output_section_generic(Output_section* os, unsigned int type, + Output_data* od, Relobj* relobj, + unsigned int shndx, uint64_t address, + uint64_t addend) + { + gold_assert(addend == 0); + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(os, type, sized_relobj, shndx, + convert_types<Address, uint64_t>(address), + false)); + } + + // As above, but the reloc TYPE is relative + + void + add_output_section_relative(Output_section* os, unsigned int type, + Output_data* od, Address address) + { this->add(od, Output_reloc_type(os, type, od, address, true)); } + + void + add_output_section_relative(Output_section* os, unsigned int type, + Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { this->add(od, Output_reloc_type(os, type, relobj, shndx, address, true)); } + + // Add an absolute relocation. + + void + add_absolute(unsigned int type, Output_data* od, Address address) + { this->add(od, Output_reloc_type(type, od, address, false)); } + + void + add_absolute(unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { this->add(od, Output_reloc_type(type, relobj, shndx, address, false)); } + + // Add a relative relocation + + void + add_relative(unsigned int type, Output_data* od, Address address) + { this->add(od, Output_reloc_type(type, od, address, true)); } + + void + add_relative(unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { this->add(od, Output_reloc_type(type, relobj, shndx, address, true)); } + + // Add a target specific relocation. A target which calls this must + // define the reloc_symbol_index and reloc_addend virtual functions. + + void + add_target_specific(unsigned int type, void* arg, Output_data* od, + Address address) + { this->add(od, Output_reloc_type(type, arg, od, address)); } + + void + add_target_specific(unsigned int type, void* arg, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address) + { this->add(od, Output_reloc_type(type, arg, relobj, shndx, address)); } +}; + +// The SHT_RELA version of Output_data_reloc. + +template<bool dynamic, int size, bool big_endian> +class Output_data_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian> + : public Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian> +{ + private: + typedef Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, + big_endian> Base; + + public: + typedef typename Base::Output_reloc_type Output_reloc_type; + typedef typename Output_reloc_type::Address Address; + typedef typename Output_reloc_type::Addend Addend; + + Output_data_reloc(bool sr) + : Output_data_reloc_base<elfcpp::SHT_RELA, dynamic, size, big_endian>(sr) + { } + + // Add a reloc against a global symbol. + + void + add_global(Symbol* gsym, unsigned int type, Output_data* od, + Address address, Addend addend) + { + this->add(od, Output_reloc_type(gsym, type, od, address, addend, + false, false, false)); + } + + void + add_global(Symbol* gsym, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, + Addend addend) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + addend, false, false, false)); + } + + void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + uint64_t address, uint64_t addend) + { + this->add(od, Output_reloc_type(gsym, type, od, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false, false, false)); + } + + void + add_global_generic(Symbol* gsym, unsigned int type, Output_data* od, + Relobj* relobj, unsigned int shndx, uint64_t address, + uint64_t addend) + { + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(gsym, type, sized_relobj, shndx, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false, false, false)); + } + + // Add a RELATIVE reloc against a global symbol. The final output + // relocation will not reference the symbol, but we must keep the symbol + // information long enough to set the addend of the relocation correctly + // when it is written. + + void + add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, + Address address, Addend addend, bool use_plt_offset) + { + this->add(od, Output_reloc_type(gsym, type, od, address, addend, true, + true, use_plt_offset)); + } + + void + add_global_relative(Symbol* gsym, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend, + bool use_plt_offset) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + addend, true, true, use_plt_offset)); + } + + // Add a global relocation which does not use a symbol for the relocation, + // but which gets its addend from a symbol. + + void + add_symbolless_global_addend(Symbol* gsym, unsigned int type, Output_data* od, + Address address, Addend addend) + { + this->add(od, Output_reloc_type(gsym, type, od, address, addend, + false, true, false)); + } + + void + add_symbolless_global_addend(Symbol* gsym, unsigned int type, + Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, + Addend addend) + { + this->add(od, Output_reloc_type(gsym, type, relobj, shndx, address, + addend, false, true, false)); + } + + // Add a reloc against a local symbol. + + void + add_local(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address, Addend addend) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, + addend, false, false, false, false)); + } + + void + add_local(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, Address address, + Addend addend) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, addend, false, false, false, + false)); + } + + void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, uint64_t address, + uint64_t addend) + { + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian> *>(relobj); + this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, od, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false, false, false, false)); + } + + void + add_local_generic(Relobj* relobj, unsigned int local_sym_index, + unsigned int type, Output_data* od, unsigned int shndx, + uint64_t address, uint64_t addend) + { + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(sized_relobj, local_sym_index, type, shndx, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false, false, false, false)); + } + + // Add a RELATIVE reloc against a local symbol. + + void + add_local_relative(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address, Addend addend, + bool use_plt_offset) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, + addend, true, true, false, + use_plt_offset)); + } + + void + add_local_relative(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, Address address, + Addend addend, bool use_plt_offset) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, addend, true, true, false, + use_plt_offset)); + } + + // Add a local relocation which does not use a symbol for the relocation, + // but which gets it's addend from a symbol. + + void + add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, Address address, Addend addend) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, od, address, + addend, false, true, false, false)); + } + + void + add_symbolless_local_addend(Sized_relobj<size, big_endian>* relobj, + unsigned int local_sym_index, unsigned int type, + Output_data* od, unsigned int shndx, + Address address, Addend addend) + { + this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx, + address, addend, false, true, false, + false)); + } + + // Add a reloc against a local section symbol. This will be + // converted into a reloc against the STT_SECTION symbol of the + // output section. + + void + add_local_section(Sized_relobj<size, big_endian>* relobj, + unsigned int input_shndx, unsigned int type, + Output_data* od, Address address, Addend addend) + { + this->add(od, Output_reloc_type(relobj, input_shndx, type, od, address, + addend, false, false, true, false)); + } + + void + add_local_section(Sized_relobj<size, big_endian>* relobj, + unsigned int input_shndx, unsigned int type, + Output_data* od, unsigned int shndx, Address address, + Addend addend) + { + this->add(od, Output_reloc_type(relobj, input_shndx, type, shndx, + address, addend, false, false, true, + false)); + } + + // A reloc against the STT_SECTION symbol of an output section. + + void + add_output_section(Output_section* os, unsigned int type, Output_data* od, + Address address, Addend addend) + { this->add(od, Output_reloc_type(os, type, od, address, addend, false)); } + + void + add_output_section(Output_section* os, unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend) + { + this->add(od, Output_reloc_type(os, type, relobj, shndx, address, + addend, false)); + } + + void + add_output_section_generic(Output_section* os, unsigned int type, + Output_data* od, uint64_t address, + uint64_t addend) + { + this->add(od, Output_reloc_type(os, type, od, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false)); + } + + void + add_output_section_generic(Output_section* os, unsigned int type, + Output_data* od, Relobj* relobj, + unsigned int shndx, uint64_t address, + uint64_t addend) + { + Sized_relobj<size, big_endian>* sized_relobj = + static_cast<Sized_relobj<size, big_endian>*>(relobj); + this->add(od, Output_reloc_type(os, type, sized_relobj, shndx, + convert_types<Address, uint64_t>(address), + convert_types<Addend, uint64_t>(addend), + false)); + } + + // As above, but the reloc TYPE is relative + + void + add_output_section_relative(Output_section* os, unsigned int type, + Output_data* od, Address address, Addend addend) + { this->add(od, Output_reloc_type(os, type, od, address, addend, true)); } + + void + add_output_section_relative(Output_section* os, unsigned int type, + Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, + Addend addend) + { + this->add(od, Output_reloc_type(os, type, relobj, shndx, + address, addend, true)); + } + + // Add an absolute relocation. + + void + add_absolute(unsigned int type, Output_data* od, Address address, + Addend addend) + { this->add(od, Output_reloc_type(type, od, address, addend, false)); } + + void + add_absolute(unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend) + { + this->add(od, Output_reloc_type(type, relobj, shndx, address, addend, + false)); + } + + // Add a relative relocation + + void + add_relative(unsigned int type, Output_data* od, Address address, + Addend addend) + { this->add(od, Output_reloc_type(type, od, address, addend, true)); } + + void + add_relative(unsigned int type, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend) + { + this->add(od, Output_reloc_type(type, relobj, shndx, address, addend, + true)); + } + + // Add a target specific relocation. A target which calls this must + // define the reloc_symbol_index and reloc_addend virtual functions. + + void + add_target_specific(unsigned int type, void* arg, Output_data* od, + Address address, Addend addend) + { this->add(od, Output_reloc_type(type, arg, od, address, addend)); } + + void + add_target_specific(unsigned int type, void* arg, Output_data* od, + Sized_relobj<size, big_endian>* relobj, + unsigned int shndx, Address address, Addend addend) + { + this->add(od, Output_reloc_type(type, arg, relobj, shndx, address, + addend)); + } +}; + +// Output_relocatable_relocs represents a relocation section in a +// relocatable link. The actual data is written out in the target +// hook relocate_relocs. This just saves space for it. + +template<int sh_type, int size, bool big_endian> +class Output_relocatable_relocs : public Output_section_data +{ + public: + Output_relocatable_relocs(Relocatable_relocs* rr) + : Output_section_data(Output_data::default_alignment_for_size(size)), + rr_(rr) + { } + + void + set_final_data_size(); + + // Write out the data. There is nothing to do here. + void + do_write(Output_file*) + { } + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** relocs")); } + + private: + // The relocs associated with this input section. + Relocatable_relocs* rr_; +}; + +// Handle a GROUP section. + +template<int size, bool big_endian> +class Output_data_group : public Output_section_data +{ + public: + // The constructor clears *INPUT_SHNDXES. + Output_data_group(Sized_relobj_file<size, big_endian>* relobj, + section_size_type entry_count, + elfcpp::Elf_Word flags, + std::vector<unsigned int>* input_shndxes); + + void + do_write(Output_file*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** group")); } + + // Set final data size. + void + set_final_data_size() + { this->set_data_size((this->input_shndxes_.size() + 1) * 4); } + + private: + // The input object. + Sized_relobj_file<size, big_endian>* relobj_; + // The group flag word. + elfcpp::Elf_Word flags_; + // The section indexes of the input sections in this group. + std::vector<unsigned int> input_shndxes_; +}; + +// Output_data_got is used to manage a GOT. Each entry in the GOT is +// for one symbol--either a global symbol or a local symbol in an +// object. The target specific code adds entries to the GOT as +// needed. The GOT_SIZE template parameter is the size in bits of a +// GOT entry, typically 32 or 64. + +class Output_data_got_base : public Output_section_data_build +{ + public: + Output_data_got_base(uint64_t align) + : Output_section_data_build(align) + { } + + Output_data_got_base(off_t data_size, uint64_t align) + : Output_section_data_build(data_size, align) + { } + + // Reserve the slot at index I in the GOT. + void + reserve_slot(unsigned int i) + { this->do_reserve_slot(i); } + + protected: + // Reserve the slot at index I in the GOT. + virtual void + do_reserve_slot(unsigned int i) = 0; +}; + +template<int got_size, bool big_endian> +class Output_data_got : public Output_data_got_base +{ + public: + typedef typename elfcpp::Elf_types<got_size>::Elf_Addr Valtype; + + Output_data_got() + : Output_data_got_base(Output_data::default_alignment_for_size(got_size)), + entries_(), free_list_() + { } + + Output_data_got(off_t data_size) + : Output_data_got_base(data_size, + Output_data::default_alignment_for_size(got_size)), + entries_(), free_list_() + { + // For an incremental update, we have an existing GOT section. + // Initialize the list of entries and the free list. + this->entries_.resize(data_size / (got_size / 8)); + this->free_list_.init(data_size, false); + } + + // Add an entry for a global symbol to the GOT. Return true if this + // is a new GOT entry, false if the symbol was already in the GOT. + bool + add_global(Symbol* gsym, unsigned int got_type); + + // Like add_global, but use the PLT offset of the global symbol if + // it has one. + bool + add_global_plt(Symbol* gsym, unsigned int got_type); + + // Like add_global, but for a TLS symbol where the value will be + // offset using Target::tls_offset_for_global. + bool + add_global_tls(Symbol* gsym, unsigned int got_type) + { return add_global_plt(gsym, got_type); } + + // Add an entry for a global symbol to the GOT, and add a dynamic + // relocation of type R_TYPE for the GOT entry. + void + add_global_with_rel(Symbol* gsym, unsigned int got_type, + Output_data_reloc_generic* rel_dyn, unsigned int r_type); + + // Add a pair of entries for a global symbol to the GOT, and add + // dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively. + void + add_global_pair_with_rel(Symbol* gsym, unsigned int got_type, + Output_data_reloc_generic* rel_dyn, + unsigned int r_type_1, unsigned int r_type_2); + + // Add an entry for a local symbol to the GOT. This returns true if + // this is a new GOT entry, false if the symbol already has a GOT + // entry. + bool + add_local(Relobj* object, unsigned int sym_index, unsigned int got_type); + + // Like add_local, but use the PLT offset of the local symbol if it + // has one. + bool + add_local_plt(Relobj* object, unsigned int sym_index, unsigned int got_type); + + // Like add_local, but for a TLS symbol where the value will be + // offset using Target::tls_offset_for_local. + bool + add_local_tls(Relobj* object, unsigned int sym_index, unsigned int got_type) + { return add_local_plt(object, sym_index, got_type); } + + // Add an entry for a local symbol to the GOT, and add a dynamic + // relocation of type R_TYPE for the GOT entry. + void + add_local_with_rel(Relobj* object, unsigned int sym_index, + unsigned int got_type, Output_data_reloc_generic* rel_dyn, + unsigned int r_type); + + // Add a pair of entries for a local symbol to the GOT, and add + // a dynamic relocation of type R_TYPE using the section symbol of + // the output section to which input section SHNDX maps, on the first. + // The first got entry will have a value of zero, the second the + // value of the local symbol. + void + add_local_pair_with_rel(Relobj* object, unsigned int sym_index, + unsigned int shndx, unsigned int got_type, + Output_data_reloc_generic* rel_dyn, + unsigned int r_type); + + // Add a pair of entries for a local symbol to the GOT, and add + // a dynamic relocation of type R_TYPE using STN_UNDEF on the first. + // The first got entry will have a value of zero, the second the + // value of the local symbol offset by Target::tls_offset_for_local. + void + add_local_tls_pair(Relobj* object, unsigned int sym_index, + unsigned int got_type, + Output_data_reloc_generic* rel_dyn, + unsigned int r_type); + + // Add a constant to the GOT. This returns the offset of the new + // entry from the start of the GOT. + unsigned int + add_constant(Valtype constant) + { return this->add_got_entry(Got_entry(constant)); } + + // Add a pair of constants to the GOT. This returns the offset of + // the new entry from the start of the GOT. + unsigned int + add_constant_pair(Valtype c1, Valtype c2) + { return this->add_got_entry_pair(Got_entry(c1), Got_entry(c2)); } + + // Replace GOT entry I with a new constant. + void + replace_constant(unsigned int i, Valtype constant) + { + this->replace_got_entry(i, Got_entry(constant)); + } + + // Reserve a slot in the GOT for a local symbol. + void + reserve_local(unsigned int i, Relobj* object, unsigned int sym_index, + unsigned int got_type); + + // Reserve a slot in the GOT for a global symbol. + void + reserve_global(unsigned int i, Symbol* gsym, unsigned int got_type); + + protected: + // Write out the GOT table. + void + do_write(Output_file*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** GOT")); } + + // Reserve the slot at index I in the GOT. + virtual void + do_reserve_slot(unsigned int i) + { this->free_list_.remove(i * got_size / 8, (i + 1) * got_size / 8); } + + // Return the number of words in the GOT. + unsigned int + num_entries () const + { return this->entries_.size(); } + + // Return the offset into the GOT of GOT entry I. + unsigned int + got_offset(unsigned int i) const + { return i * (got_size / 8); } + + private: + // This POD class holds a single GOT entry. + class Got_entry + { + public: + // Create a zero entry. + Got_entry() + : local_sym_index_(RESERVED_CODE), use_plt_or_tls_offset_(false) + { this->u_.constant = 0; } + + // Create a global symbol entry. + Got_entry(Symbol* gsym, bool use_plt_or_tls_offset) + : local_sym_index_(GSYM_CODE), + use_plt_or_tls_offset_(use_plt_or_tls_offset) + { this->u_.gsym = gsym; } + + // Create a local symbol entry. + Got_entry(Relobj* object, unsigned int local_sym_index, + bool use_plt_or_tls_offset) + : local_sym_index_(local_sym_index), + use_plt_or_tls_offset_(use_plt_or_tls_offset) + { + gold_assert(local_sym_index != GSYM_CODE + && local_sym_index != CONSTANT_CODE + && local_sym_index != RESERVED_CODE + && local_sym_index == this->local_sym_index_); + this->u_.object = object; + } + + // Create a constant entry. The constant is a host value--it will + // be swapped, if necessary, when it is written out. + explicit Got_entry(Valtype constant) + : local_sym_index_(CONSTANT_CODE), use_plt_or_tls_offset_(false) + { this->u_.constant = constant; } + + // Write the GOT entry to an output view. + void + write(unsigned int got_indx, unsigned char* pov) const; + + private: + enum + { + GSYM_CODE = 0x7fffffff, + CONSTANT_CODE = 0x7ffffffe, + RESERVED_CODE = 0x7ffffffd + }; + + union + { + // For a local symbol, the object. + Relobj* object; + // For a global symbol, the symbol. + Symbol* gsym; + // For a constant, the constant. + Valtype constant; + } u_; + // For a local symbol, the local symbol index. This is GSYM_CODE + // for a global symbol, or CONSTANT_CODE for a constant. + unsigned int local_sym_index_ : 31; + // Whether to use the PLT offset of the symbol if it has one. + // For TLS symbols, whether to offset the symbol value. + bool use_plt_or_tls_offset_ : 1; + }; + + typedef std::vector<Got_entry> Got_entries; + + // Create a new GOT entry and return its offset. + unsigned int + add_got_entry(Got_entry got_entry); + + // Create a pair of new GOT entries and return the offset of the first. + unsigned int + add_got_entry_pair(Got_entry got_entry_1, Got_entry got_entry_2); + + // Replace GOT entry I with a new value. + void + replace_got_entry(unsigned int i, Got_entry got_entry); + + // Return the offset into the GOT of the last entry added. + unsigned int + last_got_offset() const + { return this->got_offset(this->num_entries() - 1); } + + // Set the size of the section. + void + set_got_size() + { this->set_current_data_size(this->got_offset(this->num_entries())); } + + // The list of GOT entries. + Got_entries entries_; + + // List of available regions within the section, for incremental + // update links. + Free_list free_list_; +}; + +// Output_data_dynamic is used to hold the data in SHT_DYNAMIC +// section. + +class Output_data_dynamic : public Output_section_data +{ + public: + Output_data_dynamic(Stringpool* pool) + : Output_section_data(Output_data::default_alignment()), + entries_(), pool_(pool) + { } + + // Add a new dynamic entry with a fixed numeric value. + void + add_constant(elfcpp::DT tag, unsigned int val) + { this->add_entry(Dynamic_entry(tag, val)); } + + // Add a new dynamic entry with the address of output data. + void + add_section_address(elfcpp::DT tag, const Output_data* od) + { this->add_entry(Dynamic_entry(tag, od, false)); } + + // Add a new dynamic entry with the address of output data + // plus a constant offset. + void + add_section_plus_offset(elfcpp::DT tag, const Output_data* od, + unsigned int offset) + { this->add_entry(Dynamic_entry(tag, od, offset)); } + + // Add a new dynamic entry with the size of output data. + void + add_section_size(elfcpp::DT tag, const Output_data* od) + { this->add_entry(Dynamic_entry(tag, od, true)); } + + // Add a new dynamic entry with the total size of two output datas. + void + add_section_size(elfcpp::DT tag, const Output_data* od, + const Output_data* od2) + { this->add_entry(Dynamic_entry(tag, od, od2)); } + + // Add a new dynamic entry with the address of a symbol. + void + add_symbol(elfcpp::DT tag, const Symbol* sym) + { this->add_entry(Dynamic_entry(tag, sym)); } + + // Add a new dynamic entry with a string. + void + add_string(elfcpp::DT tag, const char* str) + { this->add_entry(Dynamic_entry(tag, this->pool_->add(str, true, NULL))); } + + void + add_string(elfcpp::DT tag, const std::string& str) + { this->add_string(tag, str.c_str()); } + + protected: + // Adjust the output section to set the entry size. + void + do_adjust_output_section(Output_section*); + + // Set the final data size. + void + set_final_data_size(); + + // Write out the dynamic entries. + void + do_write(Output_file*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** dynamic")); } + + private: + // This POD class holds a single dynamic entry. + class Dynamic_entry + { + public: + // Create an entry with a fixed numeric value. + Dynamic_entry(elfcpp::DT tag, unsigned int val) + : tag_(tag), offset_(DYNAMIC_NUMBER) + { this->u_.val = val; } + + // Create an entry with the size or address of a section. + Dynamic_entry(elfcpp::DT tag, const Output_data* od, bool section_size) + : tag_(tag), + offset_(section_size + ? DYNAMIC_SECTION_SIZE + : DYNAMIC_SECTION_ADDRESS) + { + this->u_.od = od; + this->od2 = NULL; + } + + // Create an entry with the size of two sections. + Dynamic_entry(elfcpp::DT tag, const Output_data* od, const Output_data* od2) + : tag_(tag), + offset_(DYNAMIC_SECTION_SIZE) + { + this->u_.od = od; + this->od2 = od2; + } + + // Create an entry with the address of a section plus a constant offset. + Dynamic_entry(elfcpp::DT tag, const Output_data* od, unsigned int offset) + : tag_(tag), + offset_(offset) + { this->u_.od = od; } + + // Create an entry with the address of a symbol. + Dynamic_entry(elfcpp::DT tag, const Symbol* sym) + : tag_(tag), offset_(DYNAMIC_SYMBOL) + { this->u_.sym = sym; } + + // Create an entry with a string. + Dynamic_entry(elfcpp::DT tag, const char* str) + : tag_(tag), offset_(DYNAMIC_STRING) + { this->u_.str = str; } + + // Return the tag of this entry. + elfcpp::DT + tag() const + { return this->tag_; } + + // Write the dynamic entry to an output view. + template<int size, bool big_endian> + void + write(unsigned char* pov, const Stringpool*) const; + + private: + // Classification is encoded in the OFFSET field. + enum Classification + { + // Section address. + DYNAMIC_SECTION_ADDRESS = 0, + // Number. + DYNAMIC_NUMBER = -1U, + // Section size. + DYNAMIC_SECTION_SIZE = -2U, + // Symbol adress. + DYNAMIC_SYMBOL = -3U, + // String. + DYNAMIC_STRING = -4U + // Any other value indicates a section address plus OFFSET. + }; + + union + { + // For DYNAMIC_NUMBER. + unsigned int val; + // For DYNAMIC_SECTION_SIZE and section address plus OFFSET. + const Output_data* od; + // For DYNAMIC_SYMBOL. + const Symbol* sym; + // For DYNAMIC_STRING. + const char* str; + } u_; + // For DYNAMIC_SYMBOL with two sections. + const Output_data* od2; + // The dynamic tag. + elfcpp::DT tag_; + // The type of entry (Classification) or offset within a section. + unsigned int offset_; + }; + + // Add an entry to the list. + void + add_entry(const Dynamic_entry& entry) + { this->entries_.push_back(entry); } + + // Sized version of write function. + template<int size, bool big_endian> + void + sized_write(Output_file* of); + + // The type of the list of entries. + typedef std::vector<Dynamic_entry> Dynamic_entries; + + // The entries. + Dynamic_entries entries_; + // The pool used for strings. + Stringpool* pool_; +}; + +// Output_symtab_xindex is used to handle SHT_SYMTAB_SHNDX sections, +// which may be required if the object file has more than +// SHN_LORESERVE sections. + +class Output_symtab_xindex : public Output_section_data +{ + public: + Output_symtab_xindex(size_t symcount) + : Output_section_data(symcount * 4, 4, true), + entries_() + { } + + // Add an entry: symbol number SYMNDX has section SHNDX. + void + add(unsigned int symndx, unsigned int shndx) + { this->entries_.push_back(std::make_pair(symndx, shndx)); } + + protected: + void + do_write(Output_file*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** symtab xindex")); } + + private: + template<bool big_endian> + void + endian_do_write(unsigned char*); + + // It is likely that most symbols will not require entries. Rather + // than keep a vector for all symbols, we keep pairs of symbol index + // and section index. + typedef std::vector<std::pair<unsigned int, unsigned int> > Xindex_entries; + + // The entries we need. + Xindex_entries entries_; +}; + +// A relaxed input section. +class Output_relaxed_input_section : public Output_section_data_build +{ + public: + // We would like to call relobj->section_addralign(shndx) to get the + // alignment but we do not want the constructor to fail. So callers + // are repsonsible for ensuring that. + Output_relaxed_input_section(Relobj* relobj, unsigned int shndx, + uint64_t addralign) + : Output_section_data_build(addralign), relobj_(relobj), shndx_(shndx) + { } + + // Return the Relobj of this relaxed input section. + Relobj* + relobj() const + { return this->relobj_; } + + // Return the section index of this relaxed input section. + unsigned int + shndx() const + { return this->shndx_; } + + protected: + void + set_relobj(Relobj* relobj) + { this->relobj_ = relobj; } + + void + set_shndx(unsigned int shndx) + { this->shndx_ = shndx; } + + private: + Relobj* relobj_; + unsigned int shndx_; +}; + +// This class describes properties of merge data sections. It is used +// as a key type for maps. +class Merge_section_properties +{ + public: + Merge_section_properties(bool is_string, uint64_t entsize, + uint64_t addralign) + : is_string_(is_string), entsize_(entsize), addralign_(addralign) + { } + + // Whether this equals to another Merge_section_properties MSP. + bool + eq(const Merge_section_properties& msp) const + { + return ((this->is_string_ == msp.is_string_) + && (this->entsize_ == msp.entsize_) + && (this->addralign_ == msp.addralign_)); + } + + // Compute a hash value for this using 64-bit FNV-1a hash. + size_t + hash_value() const + { + uint64_t h = 14695981039346656037ULL; // FNV offset basis. + uint64_t prime = 1099511628211ULL; + h = (h ^ static_cast<uint64_t>(this->is_string_)) * prime; + h = (h ^ static_cast<uint64_t>(this->entsize_)) * prime; + h = (h ^ static_cast<uint64_t>(this->addralign_)) * prime; + return h; + } + + // Functors for associative containers. + struct equal_to + { + bool + operator()(const Merge_section_properties& msp1, + const Merge_section_properties& msp2) const + { return msp1.eq(msp2); } + }; + + struct hash + { + size_t + operator()(const Merge_section_properties& msp) const + { return msp.hash_value(); } + }; + + private: + // Whether this merge data section is for strings. + bool is_string_; + // Entsize of this merge data section. + uint64_t entsize_; + // Address alignment. + uint64_t addralign_; +}; + +// This class is used to speed up look up of special input sections in an +// Output_section. + +class Output_section_lookup_maps +{ + public: + Output_section_lookup_maps() + : is_valid_(true), merge_sections_by_properties_(), + merge_sections_by_id_(), relaxed_input_sections_by_id_() + { } + + // Whether the maps are valid. + bool + is_valid() const + { return this->is_valid_; } + + // Invalidate the maps. + void + invalidate() + { this->is_valid_ = false; } + + // Clear the maps. + void + clear() + { + this->merge_sections_by_properties_.clear(); + this->merge_sections_by_id_.clear(); + this->relaxed_input_sections_by_id_.clear(); + // A cleared map is valid. + this->is_valid_ = true; + } + + // Find a merge section by merge section properties. Return NULL if none + // is found. + Output_merge_base* + find_merge_section(const Merge_section_properties& msp) const + { + gold_assert(this->is_valid_); + Merge_sections_by_properties::const_iterator p = + this->merge_sections_by_properties_.find(msp); + return p != this->merge_sections_by_properties_.end() ? p->second : NULL; + } + + // Find a merge section by section ID of a merge input section. Return NULL + // if none is found. + Output_merge_base* + find_merge_section(const Object* object, unsigned int shndx) const + { + gold_assert(this->is_valid_); + Merge_sections_by_id::const_iterator p = + this->merge_sections_by_id_.find(Const_section_id(object, shndx)); + return p != this->merge_sections_by_id_.end() ? p->second : NULL; + } + + // Add a merge section pointed by POMB with properties MSP. + void + add_merge_section(const Merge_section_properties& msp, + Output_merge_base* pomb) + { + std::pair<Merge_section_properties, Output_merge_base*> value(msp, pomb); + std::pair<Merge_sections_by_properties::iterator, bool> result = + this->merge_sections_by_properties_.insert(value); + gold_assert(result.second); + } + + // Add a mapping from a merged input section in OBJECT with index SHNDX + // to a merge output section pointed by POMB. + void + add_merge_input_section(const Object* object, unsigned int shndx, + Output_merge_base* pomb) + { + Const_section_id csid(object, shndx); + std::pair<Const_section_id, Output_merge_base*> value(csid, pomb); + std::pair<Merge_sections_by_id::iterator, bool> result = + this->merge_sections_by_id_.insert(value); + gold_assert(result.second); + } + + // Find a relaxed input section of OBJECT with index SHNDX. + Output_relaxed_input_section* + find_relaxed_input_section(const Object* object, unsigned int shndx) const + { + gold_assert(this->is_valid_); + Relaxed_input_sections_by_id::const_iterator p = + this->relaxed_input_sections_by_id_.find(Const_section_id(object, shndx)); + return p != this->relaxed_input_sections_by_id_.end() ? p->second : NULL; + } + + // Add a relaxed input section pointed by POMB and whose original input + // section is in OBJECT with index SHNDX. + void + add_relaxed_input_section(const Relobj* relobj, unsigned int shndx, + Output_relaxed_input_section* poris) + { + Const_section_id csid(relobj, shndx); + std::pair<Const_section_id, Output_relaxed_input_section*> + value(csid, poris); + std::pair<Relaxed_input_sections_by_id::iterator, bool> result = + this->relaxed_input_sections_by_id_.insert(value); + gold_assert(result.second); + } + + private: + typedef Unordered_map<Const_section_id, Output_merge_base*, + Const_section_id_hash> + Merge_sections_by_id; + + typedef Unordered_map<Merge_section_properties, Output_merge_base*, + Merge_section_properties::hash, + Merge_section_properties::equal_to> + Merge_sections_by_properties; + + typedef Unordered_map<Const_section_id, Output_relaxed_input_section*, + Const_section_id_hash> + Relaxed_input_sections_by_id; + + // Whether this is valid + bool is_valid_; + // Merge sections by merge section properties. + Merge_sections_by_properties merge_sections_by_properties_; + // Merge sections by section IDs. + Merge_sections_by_id merge_sections_by_id_; + // Relaxed sections by section IDs. + Relaxed_input_sections_by_id relaxed_input_sections_by_id_; +}; + +// This abstract base class defines the interface for the +// types of methods used to fill free space left in an output +// section during an incremental link. These methods are used +// to insert dummy compilation units into debug info so that +// debug info consumers can scan the debug info serially. + +class Output_fill +{ + public: + Output_fill() + : is_big_endian_(parameters->target().is_big_endian()) + { } + + virtual + ~Output_fill() + { } + + // Return the smallest size chunk of free space that can be + // filled with a dummy compilation unit. + size_t + minimum_hole_size() const + { return this->do_minimum_hole_size(); } + + // Write a fill pattern of length LEN at offset OFF in the file. + void + write(Output_file* of, off_t off, size_t len) const + { this->do_write(of, off, len); } + + protected: + virtual size_t + do_minimum_hole_size() const = 0; + + virtual void + do_write(Output_file* of, off_t off, size_t len) const = 0; + + bool + is_big_endian() const + { return this->is_big_endian_; } + + private: + bool is_big_endian_; +}; + +// Fill method that introduces a dummy compilation unit in +// a .debug_info or .debug_types section. + +class Output_fill_debug_info : public Output_fill +{ + public: + Output_fill_debug_info(bool is_debug_types) + : is_debug_types_(is_debug_types) + { } + + protected: + virtual size_t + do_minimum_hole_size() const; + + virtual void + do_write(Output_file* of, off_t off, size_t len) const; + + private: + // Version of the header. + static const int version = 4; + // True if this is a .debug_types section. + bool is_debug_types_; +}; + +// Fill method that introduces a dummy compilation unit in +// a .debug_line section. + +class Output_fill_debug_line : public Output_fill +{ + public: + Output_fill_debug_line() + { } + + protected: + virtual size_t + do_minimum_hole_size() const; + + virtual void + do_write(Output_file* of, off_t off, size_t len) const; + + private: + // Version of the header. We write a DWARF-3 header because it's smaller + // and many tools have not yet been updated to understand the DWARF-4 header. + static const int version = 3; + // Length of the portion of the header that follows the header_length + // field. This includes the following fields: + // minimum_instruction_length, default_is_stmt, line_base, line_range, + // opcode_base, standard_opcode_lengths[], include_directories, filenames. + // The standard_opcode_lengths array is 12 bytes long, and the + // include_directories and filenames fields each contain only a single + // null byte. + static const size_t header_length = 19; +}; + +// An output section. We don't expect to have too many output +// sections, so we don't bother to do a template on the size. + +class Output_section : public Output_data +{ + public: + // Create an output section, giving the name, type, and flags. + Output_section(const char* name, elfcpp::Elf_Word, elfcpp::Elf_Xword); + virtual ~Output_section(); + + // Add a new input section SHNDX, named NAME, with header SHDR, from + // object OBJECT. RELOC_SHNDX is the index of a relocation section + // which applies to this section, or 0 if none, or -1 if more than + // one. HAVE_SECTIONS_SCRIPT is true if we have a SECTIONS clause + // in a linker script; in that case we need to keep track of input + // sections associated with an output section. Return the offset + // within the output section. + template<int size, bool big_endian> + off_t + add_input_section(Layout* layout, Sized_relobj_file<size, big_endian>* object, + unsigned int shndx, const char* name, + const elfcpp::Shdr<size, big_endian>& shdr, + unsigned int reloc_shndx, bool have_sections_script); + + // Add generated data POSD to this output section. + void + add_output_section_data(Output_section_data* posd); + + // Add a relaxed input section PORIS called NAME to this output section + // with LAYOUT. + void + add_relaxed_input_section(Layout* layout, + Output_relaxed_input_section* poris, + const std::string& name); + + // Return the section name. + const char* + name() const + { return this->name_; } + + // Return the section type. + elfcpp::Elf_Word + type() const + { return this->type_; } + + // Return the section flags. + elfcpp::Elf_Xword + flags() const + { return this->flags_; } + + typedef std::map<Section_id, unsigned int> Section_layout_order; + + void + update_section_layout(const Section_layout_order* order_map); + + // Update the output section flags based on input section flags. + void + update_flags_for_input_section(elfcpp::Elf_Xword flags); + + // Return the entsize field. + uint64_t + entsize() const + { return this->entsize_; } + + // Set the entsize field. + void + set_entsize(uint64_t v); + + // Set the load address. + void + set_load_address(uint64_t load_address) + { + this->load_address_ = load_address; + this->has_load_address_ = true; + } + + // Set the link field to the output section index of a section. + void + set_link_section(const Output_data* od) + { + gold_assert(this->link_ == 0 + && !this->should_link_to_symtab_ + && !this->should_link_to_dynsym_); + this->link_section_ = od; + } + + // Set the link field to a constant. + void + set_link(unsigned int v) + { + gold_assert(this->link_section_ == NULL + && !this->should_link_to_symtab_ + && !this->should_link_to_dynsym_); + this->link_ = v; + } + + // Record that this section should link to the normal symbol table. + void + set_should_link_to_symtab() + { + gold_assert(this->link_section_ == NULL + && this->link_ == 0 + && !this->should_link_to_dynsym_); + this->should_link_to_symtab_ = true; + } + + // Record that this section should link to the dynamic symbol table. + void + set_should_link_to_dynsym() + { + gold_assert(this->link_section_ == NULL + && this->link_ == 0 + && !this->should_link_to_symtab_); + this->should_link_to_dynsym_ = true; + } + + // Return the info field. + unsigned int + info() const + { + gold_assert(this->info_section_ == NULL + && this->info_symndx_ == NULL); + return this->info_; + } + + // Set the info field to the output section index of a section. + void + set_info_section(const Output_section* os) + { + gold_assert((this->info_section_ == NULL + || (this->info_section_ == os + && this->info_uses_section_index_)) + && this->info_symndx_ == NULL + && this->info_ == 0); + this->info_section_ = os; + this->info_uses_section_index_= true; + } + + // Set the info field to the symbol table index of a symbol. + void + set_info_symndx(const Symbol* sym) + { + gold_assert(this->info_section_ == NULL + && (this->info_symndx_ == NULL + || this->info_symndx_ == sym) + && this->info_ == 0); + this->info_symndx_ = sym; + } + + // Set the info field to the symbol table index of a section symbol. + void + set_info_section_symndx(const Output_section* os) + { + gold_assert((this->info_section_ == NULL + || (this->info_section_ == os + && !this->info_uses_section_index_)) + && this->info_symndx_ == NULL + && this->info_ == 0); + this->info_section_ = os; + this->info_uses_section_index_ = false; + } + + // Set the info field to a constant. + void + set_info(unsigned int v) + { + gold_assert(this->info_section_ == NULL + && this->info_symndx_ == NULL + && (this->info_ == 0 + || this->info_ == v)); + this->info_ = v; + } + + // Set the addralign field. + void + set_addralign(uint64_t v) + { this->addralign_ = v; } + + void + checkpoint_set_addralign(uint64_t val) + { + if (this->checkpoint_ != NULL) + this->checkpoint_->set_addralign(val); + } + + // Whether the output section index has been set. + bool + has_out_shndx() const + { return this->out_shndx_ != -1U; } + + // Indicate that we need a symtab index. + void + set_needs_symtab_index() + { this->needs_symtab_index_ = true; } + + // Return whether we need a symtab index. + bool + needs_symtab_index() const + { return this->needs_symtab_index_; } + + // Get the symtab index. + unsigned int + symtab_index() const + { + gold_assert(this->symtab_index_ != 0); + return this->symtab_index_; + } + + // Set the symtab index. + void + set_symtab_index(unsigned int index) + { + gold_assert(index != 0); + this->symtab_index_ = index; + } + + // Indicate that we need a dynsym index. + void + set_needs_dynsym_index() + { this->needs_dynsym_index_ = true; } + + // Return whether we need a dynsym index. + bool + needs_dynsym_index() const + { return this->needs_dynsym_index_; } + + // Get the dynsym index. + unsigned int + dynsym_index() const + { + gold_assert(this->dynsym_index_ != 0); + return this->dynsym_index_; + } + + // Set the dynsym index. + void + set_dynsym_index(unsigned int index) + { + gold_assert(index != 0); + this->dynsym_index_ = index; + } + + // Sort the attached input sections. + void + sort_attached_input_sections(); + + // Return whether the input sections sections attachd to this output + // section may require sorting. This is used to handle constructor + // priorities compatibly with GNU ld. + bool + may_sort_attached_input_sections() const + { return this->may_sort_attached_input_sections_; } + + // Record that the input sections attached to this output section + // may require sorting. + void + set_may_sort_attached_input_sections() + { this->may_sort_attached_input_sections_ = true; } + + // Returns true if input sections must be sorted according to the + // order in which their name appear in the --section-ordering-file. + bool + input_section_order_specified() + { return this->input_section_order_specified_; } + + // Record that input sections must be sorted as some of their names + // match the patterns specified through --section-ordering-file. + void + set_input_section_order_specified() + { this->input_section_order_specified_ = true; } + + // Return whether the input sections attached to this output section + // require sorting. This is used to handle constructor priorities + // compatibly with GNU ld. + bool + must_sort_attached_input_sections() const + { return this->must_sort_attached_input_sections_; } + + // Record that the input sections attached to this output section + // require sorting. + void + set_must_sort_attached_input_sections() + { this->must_sort_attached_input_sections_ = true; } + + // Get the order in which this section appears in the PT_LOAD output + // segment. + Output_section_order + order() const + { return this->order_; } + + // Set the order for this section. + void + set_order(Output_section_order order) + { this->order_ = order; } + + // Return whether this section holds relro data--data which has + // dynamic relocations but which may be marked read-only after the + // dynamic relocations have been completed. + bool + is_relro() const + { return this->is_relro_; } + + // Record that this section holds relro data. + void + set_is_relro() + { this->is_relro_ = true; } + + // Record that this section does not hold relro data. + void + clear_is_relro() + { this->is_relro_ = false; } + + // True if this is a small section: a section which holds small + // variables. + bool + is_small_section() const + { return this->is_small_section_; } + + // Record that this is a small section. + void + set_is_small_section() + { this->is_small_section_ = true; } + + // True if this is a large section: a section which holds large + // variables. + bool + is_large_section() const + { return this->is_large_section_; } + + // Record that this is a large section. + void + set_is_large_section() + { this->is_large_section_ = true; } + + // True if this is a large data (not BSS) section. + bool + is_large_data_section() + { return this->is_large_section_ && this->type_ != elfcpp::SHT_NOBITS; } + + // Return whether this section should be written after all the input + // sections are complete. + bool + after_input_sections() const + { return this->after_input_sections_; } + + // Record that this section should be written after all the input + // sections are complete. + void + set_after_input_sections() + { this->after_input_sections_ = true; } + + // Return whether this section requires postprocessing after all + // relocations have been applied. + bool + requires_postprocessing() const + { return this->requires_postprocessing_; } + + bool + is_unique_segment() const + { return this->is_unique_segment_; } + + void + set_is_unique_segment() + { this->is_unique_segment_ = true; } + + uint64_t extra_segment_flags() const + { return this->extra_segment_flags_; } + + void + set_extra_segment_flags(uint64_t flags) + { this->extra_segment_flags_ = flags; } + + uint64_t segment_alignment() const + { return this->segment_alignment_; } + + void + set_segment_alignment(uint64_t align) + { this->segment_alignment_ = align; } + + // If a section requires postprocessing, return the buffer to use. + unsigned char* + postprocessing_buffer() const + { + gold_assert(this->postprocessing_buffer_ != NULL); + return this->postprocessing_buffer_; + } + + // If a section requires postprocessing, create the buffer to use. + void + create_postprocessing_buffer(); + + // If a section requires postprocessing, this is the size of the + // buffer to which relocations should be applied. + off_t + postprocessing_buffer_size() const + { return this->current_data_size_for_child(); } + + // Modify the section name. This is only permitted for an + // unallocated section, and only before the size has been finalized. + // Otherwise the name will not get into Layout::namepool_. + void + set_name(const char* newname) + { + gold_assert((this->flags_ & elfcpp::SHF_ALLOC) == 0); + gold_assert(!this->is_data_size_valid()); + this->name_ = newname; + } + + // Return whether the offset OFFSET in the input section SHNDX in + // object OBJECT is being included in the link. + bool + is_input_address_mapped(const Relobj* object, unsigned int shndx, + off_t offset) const; + + // Return the offset within the output section of OFFSET relative to + // the start of input section SHNDX in object OBJECT. + section_offset_type + output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset) const; + + // Return the output virtual address of OFFSET relative to the start + // of input section SHNDX in object OBJECT. + uint64_t + output_address(const Relobj* object, unsigned int shndx, + off_t offset) const; + + // Look for the merged section for input section SHNDX in object + // OBJECT. If found, return true, and set *ADDR to the address of + // the start of the merged section. This is not necessary the + // output offset corresponding to input offset 0 in the section, + // since the section may be mapped arbitrarily. + bool + find_starting_output_address(const Relobj* object, unsigned int shndx, + uint64_t* addr) const; + + // Record that this output section was found in the SECTIONS clause + // of a linker script. + void + set_found_in_sections_clause() + { this->found_in_sections_clause_ = true; } + + // Return whether this output section was found in the SECTIONS + // clause of a linker script. + bool + found_in_sections_clause() const + { return this->found_in_sections_clause_; } + + // Write the section header into *OPHDR. + template<int size, bool big_endian> + void + write_header(const Layout*, const Stringpool*, + elfcpp::Shdr_write<size, big_endian>*) const; + + // The next few calls are for linker script support. + + // In some cases we need to keep a list of the input sections + // associated with this output section. We only need the list if we + // might have to change the offsets of the input section within the + // output section after we add the input section. The ordinary + // input sections will be written out when we process the object + // file, and as such we don't need to track them here. We do need + // to track Output_section_data objects here. We store instances of + // this structure in a std::vector, so it must be a POD. There can + // be many instances of this structure, so we use a union to save + // some space. + class Input_section + { + public: + Input_section() + : shndx_(0), p2align_(0) + { + this->u1_.data_size = 0; + this->u2_.object = NULL; + } + + // For an ordinary input section. + Input_section(Relobj* object, unsigned int shndx, off_t data_size, + uint64_t addralign) + : shndx_(shndx), + p2align_(ffsll(static_cast<long long>(addralign))), + section_order_index_(0) + { + gold_assert(shndx != OUTPUT_SECTION_CODE + && shndx != MERGE_DATA_SECTION_CODE + && shndx != MERGE_STRING_SECTION_CODE + && shndx != RELAXED_INPUT_SECTION_CODE); + this->u1_.data_size = data_size; + this->u2_.object = object; + } + + // For a non-merge output section. + Input_section(Output_section_data* posd) + : shndx_(OUTPUT_SECTION_CODE), p2align_(0), + section_order_index_(0) + { + this->u1_.data_size = 0; + this->u2_.posd = posd; + } + + // For a merge section. + Input_section(Output_section_data* posd, bool is_string, uint64_t entsize) + : shndx_(is_string + ? MERGE_STRING_SECTION_CODE + : MERGE_DATA_SECTION_CODE), + p2align_(0), + section_order_index_(0) + { + this->u1_.entsize = entsize; + this->u2_.posd = posd; + } + + // For a relaxed input section. + Input_section(Output_relaxed_input_section* psection) + : shndx_(RELAXED_INPUT_SECTION_CODE), p2align_(0), + section_order_index_(0) + { + this->u1_.data_size = 0; + this->u2_.poris = psection; + } + + unsigned int + section_order_index() const + { + return this->section_order_index_; + } + + void + set_section_order_index(unsigned int number) + { + this->section_order_index_ = number; + } + + // The required alignment. + uint64_t + addralign() const + { + if (this->p2align_ != 0) + return static_cast<uint64_t>(1) << (this->p2align_ - 1); + else if (!this->is_input_section()) + return this->u2_.posd->addralign(); + else + return 0; + } + + // Set the required alignment, which must be either 0 or a power of 2. + // For input sections that are sub-classes of Output_section_data, a + // alignment of zero means asking the underlying object for alignment. + void + set_addralign(uint64_t addralign) + { + if (addralign == 0) + this->p2align_ = 0; + else + { + gold_assert((addralign & (addralign - 1)) == 0); + this->p2align_ = ffsll(static_cast<long long>(addralign)); + } + } + + // Return the current required size, without finalization. + off_t + current_data_size() const; + + // Return the required size. + off_t + data_size() const; + + // Whether this is an input section. + bool + is_input_section() const + { + return (this->shndx_ != OUTPUT_SECTION_CODE + && this->shndx_ != MERGE_DATA_SECTION_CODE + && this->shndx_ != MERGE_STRING_SECTION_CODE + && this->shndx_ != RELAXED_INPUT_SECTION_CODE); + } + + // Return whether this is a merge section which matches the + // parameters. + bool + is_merge_section(bool is_string, uint64_t entsize, + uint64_t addralign) const + { + return (this->shndx_ == (is_string + ? MERGE_STRING_SECTION_CODE + : MERGE_DATA_SECTION_CODE) + && this->u1_.entsize == entsize + && this->addralign() == addralign); + } + + // Return whether this is a merge section for some input section. + bool + is_merge_section() const + { + return (this->shndx_ == MERGE_DATA_SECTION_CODE + || this->shndx_ == MERGE_STRING_SECTION_CODE); + } + + // Return whether this is a relaxed input section. + bool + is_relaxed_input_section() const + { return this->shndx_ == RELAXED_INPUT_SECTION_CODE; } + + // Return whether this is a generic Output_section_data. + bool + is_output_section_data() const + { + return this->shndx_ == OUTPUT_SECTION_CODE; + } + + // Return the object for an input section. + Relobj* + relobj() const; + + // Return the input section index for an input section. + unsigned int + shndx() const; + + // For non-input-sections, return the associated Output_section_data + // object. + Output_section_data* + output_section_data() const + { + gold_assert(!this->is_input_section()); + return this->u2_.posd; + } + + // For a merge section, return the Output_merge_base pointer. + Output_merge_base* + output_merge_base() const + { + gold_assert(this->is_merge_section()); + return this->u2_.pomb; + } + + // Return the Output_relaxed_input_section object. + Output_relaxed_input_section* + relaxed_input_section() const + { + gold_assert(this->is_relaxed_input_section()); + return this->u2_.poris; + } + + // Set the output section. + void + set_output_section(Output_section* os) + { + gold_assert(!this->is_input_section()); + Output_section_data* posd = + this->is_relaxed_input_section() ? this->u2_.poris : this->u2_.posd; + posd->set_output_section(os); + } + + // Set the address and file offset. This is called during + // Layout::finalize. SECTION_FILE_OFFSET is the file offset of + // the enclosing section. + void + set_address_and_file_offset(uint64_t address, off_t file_offset, + off_t section_file_offset); + + // Reset the address and file offset. + void + reset_address_and_file_offset(); + + // Finalize the data size. + void + finalize_data_size(); + + // Add an input section, for SHF_MERGE sections. + bool + add_input_section(Relobj* object, unsigned int shndx) + { + gold_assert(this->shndx_ == MERGE_DATA_SECTION_CODE + || this->shndx_ == MERGE_STRING_SECTION_CODE); + return this->u2_.posd->add_input_section(object, shndx); + } + + // Given an input OBJECT, an input section index SHNDX within that + // object, and an OFFSET relative to the start of that input + // section, return whether or not the output offset is known. If + // this function returns true, it sets *POUTPUT to the offset in + // the output section, relative to the start of the input section + // in the output section. *POUTPUT may be different from OFFSET + // for a merged section. + bool + output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset, + section_offset_type* poutput) const; + + // Return whether this is the merge section for the input section + // SHNDX in OBJECT. + bool + is_merge_section_for(const Relobj* object, unsigned int shndx) const; + + // Write out the data. This does nothing for an input section. + void + write(Output_file*); + + // Write the data to a buffer. This does nothing for an input + // section. + void + write_to_buffer(unsigned char*); + + // Print to a map file. + void + print_to_mapfile(Mapfile*) const; + + // Print statistics about merge sections to stderr. + void + print_merge_stats(const char* section_name) + { + if (this->shndx_ == MERGE_DATA_SECTION_CODE + || this->shndx_ == MERGE_STRING_SECTION_CODE) + this->u2_.posd->print_merge_stats(section_name); + } + + private: + // Code values which appear in shndx_. If the value is not one of + // these codes, it is the input section index in the object file. + enum + { + // An Output_section_data. + OUTPUT_SECTION_CODE = -1U, + // An Output_section_data for an SHF_MERGE section with + // SHF_STRINGS not set. + MERGE_DATA_SECTION_CODE = -2U, + // An Output_section_data for an SHF_MERGE section with + // SHF_STRINGS set. + MERGE_STRING_SECTION_CODE = -3U, + // An Output_section_data for a relaxed input section. + RELAXED_INPUT_SECTION_CODE = -4U + }; + + // For an ordinary input section, this is the section index in the + // input file. For an Output_section_data, this is + // OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or + // MERGE_STRING_SECTION_CODE. + unsigned int shndx_; + // The required alignment, stored as a power of 2. + unsigned int p2align_; + union + { + // For an ordinary input section, the section size. + off_t data_size; + // For OUTPUT_SECTION_CODE or RELAXED_INPUT_SECTION_CODE, this is not + // used. For MERGE_DATA_SECTION_CODE or MERGE_STRING_SECTION_CODE, the + // entity size. + uint64_t entsize; + } u1_; + union + { + // For an ordinary input section, the object which holds the + // input section. + Relobj* object; + // For OUTPUT_SECTION_CODE or MERGE_DATA_SECTION_CODE or + // MERGE_STRING_SECTION_CODE, the data. + Output_section_data* posd; + Output_merge_base* pomb; + // For RELAXED_INPUT_SECTION_CODE, the data. + Output_relaxed_input_section* poris; + } u2_; + // The line number of the pattern it matches in the --section-ordering-file + // file. It is 0 if does not match any pattern. + unsigned int section_order_index_; + }; + + // Store the list of input sections for this Output_section into the + // list passed in. This removes the input sections, leaving only + // any Output_section_data elements. This returns the size of those + // Output_section_data elements. ADDRESS is the address of this + // output section. FILL is the fill value to use, in case there are + // any spaces between the remaining Output_section_data elements. + uint64_t + get_input_sections(uint64_t address, const std::string& fill, + std::list<Input_section>*); + + // Add a script input section. A script input section can either be + // a plain input section or a sub-class of Output_section_data. + void + add_script_input_section(const Input_section& input_section); + + // Set the current size of the output section. + void + set_current_data_size(off_t size) + { this->set_current_data_size_for_child(size); } + + // End of linker script support. + + // Save states before doing section layout. + // This is used for relaxation. + void + save_states(); + + // Restore states prior to section layout. + void + restore_states(); + + // Discard states. + void + discard_states(); + + // Convert existing input sections to relaxed input sections. + void + convert_input_sections_to_relaxed_sections( + const std::vector<Output_relaxed_input_section*>& sections); + + // Find a relaxed input section to an input section in OBJECT + // with index SHNDX. Return NULL if none is found. + const Output_relaxed_input_section* + find_relaxed_input_section(const Relobj* object, unsigned int shndx) const; + + // Whether section offsets need adjustment due to relaxation. + bool + section_offsets_need_adjustment() const + { return this->section_offsets_need_adjustment_; } + + // Set section_offsets_need_adjustment to be true. + void + set_section_offsets_need_adjustment() + { this->section_offsets_need_adjustment_ = true; } + + // Set section_offsets_need_adjustment to be false. + void + clear_section_offsets_need_adjustment() + { this->section_offsets_need_adjustment_ = false; } + + // Adjust section offsets of input sections in this. This is + // requires if relaxation caused some input sections to change sizes. + void + adjust_section_offsets(); + + // Whether this is a NOLOAD section. + bool + is_noload() const + { return this->is_noload_; } + + // Set NOLOAD flag. + void + set_is_noload() + { this->is_noload_ = true; } + + // Print merge statistics to stderr. + void + print_merge_stats(); + + // Set a fixed layout for the section. Used for incremental update links. + void + set_fixed_layout(uint64_t sh_addr, off_t sh_offset, off_t sh_size, + uint64_t sh_addralign); + + // Return TRUE if the section has a fixed layout. + bool + has_fixed_layout() const + { return this->has_fixed_layout_; } + + // Set flag to allow patch space for this section. Used for full + // incremental links. + void + set_is_patch_space_allowed() + { this->is_patch_space_allowed_ = true; } + + // Set a fill method to use for free space left in the output section + // during incremental links. + void + set_free_space_fill(Output_fill* free_space_fill) + { + this->free_space_fill_ = free_space_fill; + this->free_list_.set_min_hole_size(free_space_fill->minimum_hole_size()); + } + + // Reserve space within the fixed layout for the section. Used for + // incremental update links. + void + reserve(uint64_t sh_offset, uint64_t sh_size); + + // Allocate space from the free list for the section. Used for + // incremental update links. + off_t + allocate(off_t len, uint64_t addralign); + + typedef std::vector<Input_section> Input_section_list; + + // Allow access to the input sections. + const Input_section_list& + input_sections() const + { return this->input_sections_; } + + Input_section_list& + input_sections() + { return this->input_sections_; } + + protected: + // Return the output section--i.e., the object itself. + Output_section* + do_output_section() + { return this; } + + const Output_section* + do_output_section() const + { return this; } + + // Return the section index in the output file. + unsigned int + do_out_shndx() const + { + gold_assert(this->out_shndx_ != -1U); + return this->out_shndx_; + } + + // Set the output section index. + void + do_set_out_shndx(unsigned int shndx) + { + gold_assert(this->out_shndx_ == -1U || this->out_shndx_ == shndx); + this->out_shndx_ = shndx; + } + + // Update the data size of the Output_section. For a typical + // Output_section, there is nothing to do, but if there are any + // Output_section_data objects we need to do a trial layout + // here. + virtual void + update_data_size(); + + // Set the final data size of the Output_section. For a typical + // Output_section, there is nothing to do, but if there are any + // Output_section_data objects we need to set their final addresses + // here. + virtual void + set_final_data_size(); + + // Reset the address and file offset. + void + do_reset_address_and_file_offset(); + + // Return true if address and file offset already have reset values. In + // other words, calling reset_address_and_file_offset will not change them. + bool + do_address_and_file_offset_have_reset_values() const; + + // Write the data to the file. For a typical Output_section, this + // does nothing: the data is written out by calling Object::Relocate + // on each input object. But if there are any Output_section_data + // objects we do need to write them out here. + virtual void + do_write(Output_file*); + + // Return the address alignment--function required by parent class. + uint64_t + do_addralign() const + { return this->addralign_; } + + // Return whether there is a load address. + bool + do_has_load_address() const + { return this->has_load_address_; } + + // Return the load address. + uint64_t + do_load_address() const + { + gold_assert(this->has_load_address_); + return this->load_address_; + } + + // Return whether this is an Output_section. + bool + do_is_section() const + { return true; } + + // Return whether this is a section of the specified type. + bool + do_is_section_type(elfcpp::Elf_Word type) const + { return this->type_ == type; } + + // Return whether the specified section flag is set. + bool + do_is_section_flag_set(elfcpp::Elf_Xword flag) const + { return (this->flags_ & flag) != 0; } + + // Set the TLS offset. Called only for SHT_TLS sections. + void + do_set_tls_offset(uint64_t tls_base); + + // Return the TLS offset, relative to the base of the TLS segment. + // Valid only for SHT_TLS sections. + uint64_t + do_tls_offset() const + { return this->tls_offset_; } + + // This may be implemented by a child class. + virtual void + do_finalize_name(Layout*) + { } + + // Print to the map file. + virtual void + do_print_to_mapfile(Mapfile*) const; + + // Record that this section requires postprocessing after all + // relocations have been applied. This is called by a child class. + void + set_requires_postprocessing() + { + this->requires_postprocessing_ = true; + this->after_input_sections_ = true; + } + + // Write all the data of an Output_section into the postprocessing + // buffer. + void + write_to_postprocessing_buffer(); + + // Whether this always keeps an input section list + bool + always_keeps_input_sections() const + { return this->always_keeps_input_sections_; } + + // Always keep an input section list. + void + set_always_keeps_input_sections() + { + gold_assert(this->current_data_size_for_child() == 0); + this->always_keeps_input_sections_ = true; + } + + private: + // We only save enough information to undo the effects of section layout. + class Checkpoint_output_section + { + public: + Checkpoint_output_section(uint64_t addralign, elfcpp::Elf_Xword flags, + const Input_section_list& input_sections, + off_t first_input_offset, + bool attached_input_sections_are_sorted) + : addralign_(addralign), flags_(flags), + input_sections_(input_sections), + input_sections_size_(input_sections_.size()), + input_sections_copy_(), first_input_offset_(first_input_offset), + attached_input_sections_are_sorted_(attached_input_sections_are_sorted) + { } + + virtual + ~Checkpoint_output_section() + { } + + // Return the address alignment. + uint64_t + addralign() const + { return this->addralign_; } + + void + set_addralign(uint64_t val) + { this->addralign_ = val; } + + // Return the section flags. + elfcpp::Elf_Xword + flags() const + { return this->flags_; } + + // Return a reference to the input section list copy. + Input_section_list* + input_sections() + { return &this->input_sections_copy_; } + + // Return the size of input_sections at the time when checkpoint is + // taken. + size_t + input_sections_size() const + { return this->input_sections_size_; } + + // Whether input sections are copied. + bool + input_sections_saved() const + { return this->input_sections_copy_.size() == this->input_sections_size_; } + + off_t + first_input_offset() const + { return this->first_input_offset_; } + + bool + attached_input_sections_are_sorted() const + { return this->attached_input_sections_are_sorted_; } + + // Save input sections. + void + save_input_sections() + { + this->input_sections_copy_.reserve(this->input_sections_size_); + this->input_sections_copy_.clear(); + Input_section_list::const_iterator p = this->input_sections_.begin(); + gold_assert(this->input_sections_size_ >= this->input_sections_.size()); + for(size_t i = 0; i < this->input_sections_size_ ; i++, ++p) + this->input_sections_copy_.push_back(*p); + } + + private: + // The section alignment. + uint64_t addralign_; + // The section flags. + elfcpp::Elf_Xword flags_; + // Reference to the input sections to be checkpointed. + const Input_section_list& input_sections_; + // Size of the checkpointed portion of input_sections_; + size_t input_sections_size_; + // Copy of input sections. + Input_section_list input_sections_copy_; + // The offset of the first entry in input_sections_. + off_t first_input_offset_; + // True if the input sections attached to this output section have + // already been sorted. + bool attached_input_sections_are_sorted_; + }; + + // This class is used to sort the input sections. + class Input_section_sort_entry; + + // This is the sort comparison function for ctors and dtors. + struct Input_section_sort_compare + { + bool + operator()(const Input_section_sort_entry&, + const Input_section_sort_entry&) const; + }; + + // This is the sort comparison function for .init_array and .fini_array. + struct Input_section_sort_init_fini_compare + { + bool + operator()(const Input_section_sort_entry&, + const Input_section_sort_entry&) const; + }; + + // This is the sort comparison function when a section order is specified + // from an input file. + struct Input_section_sort_section_order_index_compare + { + bool + operator()(const Input_section_sort_entry&, + const Input_section_sort_entry&) const; + }; + + // This is the sort comparison function for .text to sort sections with + // prefixes .text.{unlikely,exit,startup,hot} before other sections. + struct Input_section_sort_section_prefix_special_ordering_compare + { + bool + operator()(const Input_section_sort_entry&, + const Input_section_sort_entry&) const; + }; + + // This is the sort comparison function for sorting sections by name. + struct Input_section_sort_section_name_compare + { + bool + operator()(const Input_section_sort_entry&, + const Input_section_sort_entry&) const; + }; + + // Fill data. This is used to fill in data between input sections. + // It is also used for data statements (BYTE, WORD, etc.) in linker + // scripts. When we have to keep track of the input sections, we + // can use an Output_data_const, but we don't want to have to keep + // track of input sections just to implement fills. + class Fill + { + public: + Fill(off_t section_offset, off_t length) + : section_offset_(section_offset), + length_(convert_to_section_size_type(length)) + { } + + // Return section offset. + off_t + section_offset() const + { return this->section_offset_; } + + // Return fill length. + section_size_type + length() const + { return this->length_; } + + private: + // The offset within the output section. + off_t section_offset_; + // The length of the space to fill. + section_size_type length_; + }; + + typedef std::vector<Fill> Fill_list; + + // Map used during relaxation of existing sections. This map + // a section id an input section list index. We assume that + // Input_section_list is a vector. + typedef Unordered_map<Section_id, size_t, Section_id_hash> Relaxation_map; + + // Add a new output section by Input_section. + void + add_output_section_data(Input_section*); + + // Add an SHF_MERGE input section. Returns true if the section was + // handled. If KEEPS_INPUT_SECTIONS is true, the output merge section + // stores information about the merged input sections. + bool + add_merge_input_section(Relobj* object, unsigned int shndx, uint64_t flags, + uint64_t entsize, uint64_t addralign, + bool keeps_input_sections); + + // Add an output SHF_MERGE section POSD to this output section. + // IS_STRING indicates whether it is a SHF_STRINGS section, and + // ENTSIZE is the entity size. This returns the entry added to + // input_sections_. + void + add_output_merge_section(Output_section_data* posd, bool is_string, + uint64_t entsize); + + // Find the merge section into which an input section with index SHNDX in + // OBJECT has been added. Return NULL if none found. + Output_section_data* + find_merge_section(const Relobj* object, unsigned int shndx) const; + + // Build a relaxation map. + void + build_relaxation_map( + const Input_section_list& input_sections, + size_t limit, + Relaxation_map* map) const; + + // Convert input sections in an input section list into relaxed sections. + void + convert_input_sections_in_list_to_relaxed_sections( + const std::vector<Output_relaxed_input_section*>& relaxed_sections, + const Relaxation_map& map, + Input_section_list* input_sections); + + // Build the lookup maps for merge and relaxed input sections. + void + build_lookup_maps() const; + + // Most of these fields are only valid after layout. + + // The name of the section. This will point into a Stringpool. + const char* name_; + // The section address is in the parent class. + // The section alignment. + uint64_t addralign_; + // The section entry size. + uint64_t entsize_; + // The load address. This is only used when using a linker script + // with a SECTIONS clause. The has_load_address_ field indicates + // whether this field is valid. + uint64_t load_address_; + // The file offset is in the parent class. + // Set the section link field to the index of this section. + const Output_data* link_section_; + // If link_section_ is NULL, this is the link field. + unsigned int link_; + // Set the section info field to the index of this section. + const Output_section* info_section_; + // If info_section_ is NULL, set the info field to the symbol table + // index of this symbol. + const Symbol* info_symndx_; + // If info_section_ and info_symndx_ are NULL, this is the section + // info field. + unsigned int info_; + // The section type. + const elfcpp::Elf_Word type_; + // The section flags. + elfcpp::Elf_Xword flags_; + // The order of this section in the output segment. + Output_section_order order_; + // The section index. + unsigned int out_shndx_; + // If there is a STT_SECTION for this output section in the normal + // symbol table, this is the symbol index. This starts out as zero. + // It is initialized in Layout::finalize() to be the index, or -1U + // if there isn't one. + unsigned int symtab_index_; + // If there is a STT_SECTION for this output section in the dynamic + // symbol table, this is the symbol index. This starts out as zero. + // It is initialized in Layout::finalize() to be the index, or -1U + // if there isn't one. + unsigned int dynsym_index_; + // The input sections. This will be empty in cases where we don't + // need to keep track of them. + Input_section_list input_sections_; + // The offset of the first entry in input_sections_. + off_t first_input_offset_; + // The fill data. This is separate from input_sections_ because we + // often will need fill sections without needing to keep track of + // input sections. + Fill_list fills_; + // If the section requires postprocessing, this buffer holds the + // section contents during relocation. + unsigned char* postprocessing_buffer_; + // Whether this output section needs a STT_SECTION symbol in the + // normal symbol table. This will be true if there is a relocation + // which needs it. + bool needs_symtab_index_ : 1; + // Whether this output section needs a STT_SECTION symbol in the + // dynamic symbol table. This will be true if there is a dynamic + // relocation which needs it. + bool needs_dynsym_index_ : 1; + // Whether the link field of this output section should point to the + // normal symbol table. + bool should_link_to_symtab_ : 1; + // Whether the link field of this output section should point to the + // dynamic symbol table. + bool should_link_to_dynsym_ : 1; + // Whether this section should be written after all the input + // sections are complete. + bool after_input_sections_ : 1; + // Whether this section requires post processing after all + // relocations have been applied. + bool requires_postprocessing_ : 1; + // Whether an input section was mapped to this output section + // because of a SECTIONS clause in a linker script. + bool found_in_sections_clause_ : 1; + // Whether this section has an explicitly specified load address. + bool has_load_address_ : 1; + // True if the info_section_ field means the section index of the + // section, false if it means the symbol index of the corresponding + // section symbol. + bool info_uses_section_index_ : 1; + // True if input sections attached to this output section have to be + // sorted according to a specified order. + bool input_section_order_specified_ : 1; + // True if the input sections attached to this output section may + // need sorting. + bool may_sort_attached_input_sections_ : 1; + // True if the input sections attached to this output section must + // be sorted. + bool must_sort_attached_input_sections_ : 1; + // True if the input sections attached to this output section have + // already been sorted. + bool attached_input_sections_are_sorted_ : 1; + // True if this section holds relro data. + bool is_relro_ : 1; + // True if this is a small section. + bool is_small_section_ : 1; + // True if this is a large section. + bool is_large_section_ : 1; + // Whether code-fills are generated at write. + bool generate_code_fills_at_write_ : 1; + // Whether the entry size field should be zero. + bool is_entsize_zero_ : 1; + // Whether section offsets need adjustment due to relaxation. + bool section_offsets_need_adjustment_ : 1; + // Whether this is a NOLOAD section. + bool is_noload_ : 1; + // Whether this always keeps input section. + bool always_keeps_input_sections_ : 1; + // Whether this section has a fixed layout, for incremental update links. + bool has_fixed_layout_ : 1; + // True if we can add patch space to this section. + bool is_patch_space_allowed_ : 1; + // True if this output section goes into a unique segment. + bool is_unique_segment_ : 1; + // For SHT_TLS sections, the offset of this section relative to the base + // of the TLS segment. + uint64_t tls_offset_; + // Additional segment flags, specified via linker plugin, when mapping some + // input sections to unique segments. + uint64_t extra_segment_flags_; + // Segment alignment specified via linker plugin, when mapping some + // input sections to unique segments. + uint64_t segment_alignment_; + // Saved checkpoint. + Checkpoint_output_section* checkpoint_; + // Fast lookup maps for merged and relaxed input sections. + Output_section_lookup_maps* lookup_maps_; + // List of available regions within the section, for incremental + // update links. + Free_list free_list_; + // Method for filling chunks of free space. + Output_fill* free_space_fill_; + // Amount added as patch space for incremental linking. + off_t patch_space_; +}; + +// An output segment. PT_LOAD segments are built from collections of +// output sections. Other segments typically point within PT_LOAD +// segments, and are built directly as needed. +// +// NOTE: We want to use the copy constructor for this class. During +// relaxation, we may try built the segments multiple times. We do +// that by copying the original segment list before lay-out, doing +// a trial lay-out and roll-back to the saved copied if we need to +// to the lay-out again. + +class Output_segment +{ + public: + // Create an output segment, specifying the type and flags. + Output_segment(elfcpp::Elf_Word, elfcpp::Elf_Word); + + // Return the virtual address. + uint64_t + vaddr() const + { return this->vaddr_; } + + // Return the physical address. + uint64_t + paddr() const + { return this->paddr_; } + + // Return the segment type. + elfcpp::Elf_Word + type() const + { return this->type_; } + + // Return the segment flags. + elfcpp::Elf_Word + flags() const + { return this->flags_; } + + // Return the memory size. + uint64_t + memsz() const + { return this->memsz_; } + + // Return the file size. + off_t + filesz() const + { return this->filesz_; } + + // Return the file offset. + off_t + offset() const + { return this->offset_; } + + // Whether this is a segment created to hold large data sections. + bool + is_large_data_segment() const + { return this->is_large_data_segment_; } + + // Record that this is a segment created to hold large data + // sections. + void + set_is_large_data_segment() + { this->is_large_data_segment_ = true; } + + bool + is_unique_segment() const + { return this->is_unique_segment_; } + + // Mark segment as unique, happens when linker plugins request that + // certain input sections be mapped to unique segments. + void + set_is_unique_segment() + { this->is_unique_segment_ = true; } + + // Return the maximum alignment of the Output_data. + uint64_t + maximum_alignment(); + + // Add the Output_section OS to this PT_LOAD segment. SEG_FLAGS is + // the segment flags to use. + void + add_output_section_to_load(Layout* layout, Output_section* os, + elfcpp::Elf_Word seg_flags); + + // Add the Output_section OS to this non-PT_LOAD segment. SEG_FLAGS + // is the segment flags to use. + void + add_output_section_to_nonload(Output_section* os, + elfcpp::Elf_Word seg_flags); + + // Remove an Output_section from this segment. It is an error if it + // is not present. + void + remove_output_section(Output_section* os); + + // Add an Output_data (which need not be an Output_section) to the + // start of this segment. + void + add_initial_output_data(Output_data*); + + // Return true if this segment has any sections which hold actual + // data, rather than being a BSS section. + bool + has_any_data_sections() const; + + // Whether this segment has a dynamic relocs. + bool + has_dynamic_reloc() const; + + // Return the first section. + Output_section* + first_section() const; + + // Return the address of the first section. + uint64_t + first_section_load_address() const + { + const Output_section* os = this->first_section(); + return os->has_load_address() ? os->load_address() : os->address(); + } + + // Return whether the addresses have been set already. + bool + are_addresses_set() const + { return this->are_addresses_set_; } + + // Set the addresses. + void + set_addresses(uint64_t vaddr, uint64_t paddr) + { + this->vaddr_ = vaddr; + this->paddr_ = paddr; + this->are_addresses_set_ = true; + } + + // Update the flags for the flags of an output section added to this + // segment. + void + update_flags_for_output_section(elfcpp::Elf_Xword flags) + { + // The ELF ABI specifies that a PT_TLS segment should always have + // PF_R as the flags. + if (this->type() != elfcpp::PT_TLS) + this->flags_ |= flags; + } + + // Set the segment flags. This is only used if we have a PHDRS + // clause which explicitly specifies the flags. + void + set_flags(elfcpp::Elf_Word flags) + { this->flags_ = flags; } + + // Set the address of the segment to ADDR and the offset to *POFF + // and set the addresses and offsets of all contained output + // sections accordingly. Set the section indexes of all contained + // output sections starting with *PSHNDX. If RESET is true, first + // reset the addresses of the contained sections. Return the + // address of the immediately following segment. Update *POFF and + // *PSHNDX. This should only be called for a PT_LOAD segment. + uint64_t + set_section_addresses(const Target*, Layout*, bool reset, uint64_t addr, + unsigned int* increase_relro, bool* has_relro, + off_t* poff, unsigned int* pshndx); + + // Set the minimum alignment of this segment. This may be adjusted + // upward based on the section alignments. + void + set_minimum_p_align(uint64_t align) + { + if (align > this->min_p_align_) + this->min_p_align_ = align; + } + + // Set the offset of this segment based on the section. This should + // only be called for a non-PT_LOAD segment. + void + set_offset(unsigned int increase); + + // Set the TLS offsets of the sections contained in the PT_TLS segment. + void + set_tls_offsets(); + + // Return the number of output sections. + unsigned int + output_section_count() const; + + // Return the section attached to the list segment with the lowest + // load address. This is used when handling a PHDRS clause in a + // linker script. + Output_section* + section_with_lowest_load_address() const; + + // Write the segment header into *OPHDR. + template<int size, bool big_endian> + void + write_header(elfcpp::Phdr_write<size, big_endian>*); + + // Write the section headers of associated sections into V. + template<int size, bool big_endian> + unsigned char* + write_section_headers(const Layout*, const Stringpool*, unsigned char* v, + unsigned int* pshndx) const; + + // Print the output sections in the map file. + void + print_sections_to_mapfile(Mapfile*) const; + + private: + typedef std::vector<Output_data*> Output_data_list; + + // Find the maximum alignment in an Output_data_list. + static uint64_t + maximum_alignment_list(const Output_data_list*); + + // Return whether the first data section is a relro section. + bool + is_first_section_relro() const; + + // Set the section addresses in an Output_data_list. + uint64_t + set_section_list_addresses(Layout*, bool reset, Output_data_list*, + uint64_t addr, off_t* poff, unsigned int* pshndx, + bool* in_tls); + + // Return the number of Output_sections in an Output_data_list. + unsigned int + output_section_count_list(const Output_data_list*) const; + + // Return whether an Output_data_list has a dynamic reloc. + bool + has_dynamic_reloc_list(const Output_data_list*) const; + + // Find the section with the lowest load address in an + // Output_data_list. + void + lowest_load_address_in_list(const Output_data_list* pdl, + Output_section** found, + uint64_t* found_lma) const; + + // Find the first and last entries by address. + void + find_first_and_last_list(const Output_data_list* pdl, + const Output_data** pfirst, + const Output_data** plast) const; + + // Write the section headers in the list into V. + template<int size, bool big_endian> + unsigned char* + write_section_headers_list(const Layout*, const Stringpool*, + const Output_data_list*, unsigned char* v, + unsigned int* pshdx) const; + + // Print a section list to the mapfile. + void + print_section_list_to_mapfile(Mapfile*, const Output_data_list*) const; + + // NOTE: We want to use the copy constructor. Currently, shallow copy + // works for us so we do not need to write our own copy constructor. + + // The list of output data attached to this segment. + Output_data_list output_lists_[ORDER_MAX]; + // The segment virtual address. + uint64_t vaddr_; + // The segment physical address. + uint64_t paddr_; + // The size of the segment in memory. + uint64_t memsz_; + // The maximum section alignment. The is_max_align_known_ field + // indicates whether this has been finalized. + uint64_t max_align_; + // The required minimum value for the p_align field. This is used + // for PT_LOAD segments. Note that this does not mean that + // addresses should be aligned to this value; it means the p_paddr + // and p_vaddr fields must be congruent modulo this value. For + // non-PT_LOAD segments, the dynamic linker works more efficiently + // if the p_align field has the more conventional value, although it + // can align as needed. + uint64_t min_p_align_; + // The offset of the segment data within the file. + off_t offset_; + // The size of the segment data in the file. + off_t filesz_; + // The segment type; + elfcpp::Elf_Word type_; + // The segment flags. + elfcpp::Elf_Word flags_; + // Whether we have finalized max_align_. + bool is_max_align_known_ : 1; + // Whether vaddr and paddr were set by a linker script. + bool are_addresses_set_ : 1; + // Whether this segment holds large data sections. + bool is_large_data_segment_ : 1; + // Whether this was marked as a unique segment via a linker plugin. + bool is_unique_segment_ : 1; +}; + +// This class represents the output file. + +class Output_file +{ + public: + Output_file(const char* name); + + // Indicate that this is a temporary file which should not be + // output. + void + set_is_temporary() + { this->is_temporary_ = true; } + + // Try to open an existing file. Returns false if the file doesn't + // exist, has a size of 0 or can't be mmaped. This method is + // thread-unsafe. If BASE_NAME is not NULL, use the contents of + // that file as the base for incremental linking. + bool + open_base_file(const char* base_name, bool writable); + + // Open the output file. FILE_SIZE is the final size of the file. + // If the file already exists, it is deleted/truncated. This method + // is thread-unsafe. + void + open(off_t file_size); + + // Resize the output file. This method is thread-unsafe. + void + resize(off_t file_size); + + // Close the output file (flushing all buffered data) and make sure + // there are no errors. This method is thread-unsafe. + void + close(); + + // Return the size of this file. + off_t + filesize() + { return this->file_size_; } + + // Return the name of this file. + const char* + filename() + { return this->name_; } + + // We currently always use mmap which makes the view handling quite + // simple. In the future we may support other approaches. + + // Write data to the output file. + void + write(off_t offset, const void* data, size_t len) + { memcpy(this->base_ + offset, data, len); } + + // Get a buffer to use to write to the file, given the offset into + // the file and the size. + unsigned char* + get_output_view(off_t start, size_t size) + { + gold_assert(start >= 0 + && start + static_cast<off_t>(size) <= this->file_size_); + return this->base_ + start; + } + + // VIEW must have been returned by get_output_view. Write the + // buffer to the file, passing in the offset and the size. + void + write_output_view(off_t, size_t, unsigned char*) + { } + + // Get a read/write buffer. This is used when we want to write part + // of the file, read it in, and write it again. + unsigned char* + get_input_output_view(off_t start, size_t size) + { return this->get_output_view(start, size); } + + // Write a read/write buffer back to the file. + void + write_input_output_view(off_t, size_t, unsigned char*) + { } + + // Get a read buffer. This is used when we just want to read part + // of the file back it in. + const unsigned char* + get_input_view(off_t start, size_t size) + { return this->get_output_view(start, size); } + + // Release a read bfufer. + void + free_input_view(off_t, size_t, const unsigned char*) + { } + + private: + // Map the file into memory or, if that fails, allocate anonymous + // memory. + void + map(); + + // Allocate anonymous memory for the file. + bool + map_anonymous(); + + // Map the file into memory. + bool + map_no_anonymous(bool); + + // Unmap the file from memory (and flush to disk buffers). + void + unmap(); + + // File name. + const char* name_; + // File descriptor. + int o_; + // File size. + off_t file_size_; + // Base of file mapped into memory. + unsigned char* base_; + // True iff base_ points to a memory buffer rather than an output file. + bool map_is_anonymous_; + // True if base_ was allocated using new rather than mmap. + bool map_is_allocated_; + // True if this is a temporary file which should not be output. + bool is_temporary_; +}; + +} // End namespace gold. + +#endif // !defined(GOLD_OUTPUT_H) |