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Diffstat (limited to 'binutils-2.25/gold/object.h')
| -rw-r--r-- | binutils-2.25/gold/object.h | 2918 |
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diff --git a/binutils-2.25/gold/object.h b/binutils-2.25/gold/object.h new file mode 100644 index 00000000..88263b4b --- /dev/null +++ b/binutils-2.25/gold/object.h @@ -0,0 +1,2918 @@ +// object.h -- support for an object file for linking in gold -*- C++ -*- + +// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 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_OBJECT_H +#define GOLD_OBJECT_H + +#include <string> +#include <vector> + +#include "elfcpp.h" +#include "elfcpp_file.h" +#include "fileread.h" +#include "target.h" +#include "archive.h" + +namespace gold +{ + +class General_options; +class Task; +class Cref; +class Layout; +class Output_data; +class Output_section; +class Output_file; +class Output_symtab_xindex; +class Pluginobj; +class Dynobj; +class Object_merge_map; +class Relocatable_relocs; +struct Symbols_data; + +template<typename Stringpool_char> +class Stringpool_template; + +// Data to pass from read_symbols() to add_symbols(). + +struct Read_symbols_data +{ + Read_symbols_data() + : section_headers(NULL), section_names(NULL), symbols(NULL), + symbol_names(NULL), versym(NULL), verdef(NULL), verneed(NULL) + { } + + ~Read_symbols_data(); + + // Section headers. + File_view* section_headers; + // Section names. + File_view* section_names; + // Size of section name data in bytes. + section_size_type section_names_size; + // Symbol data. + File_view* symbols; + // Size of symbol data in bytes. + section_size_type symbols_size; + // Offset of external symbols within symbol data. This structure + // sometimes contains only external symbols, in which case this will + // be zero. Sometimes it contains all symbols. + section_offset_type external_symbols_offset; + // Symbol names. + File_view* symbol_names; + // Size of symbol name data in bytes. + section_size_type symbol_names_size; + + // Version information. This is only used on dynamic objects. + // Version symbol data (from SHT_GNU_versym section). + File_view* versym; + section_size_type versym_size; + // Version definition data (from SHT_GNU_verdef section). + File_view* verdef; + section_size_type verdef_size; + unsigned int verdef_info; + // Needed version data (from SHT_GNU_verneed section). + File_view* verneed; + section_size_type verneed_size; + unsigned int verneed_info; +}; + +// Information used to print error messages. + +struct Symbol_location_info +{ + std::string source_file; + std::string enclosing_symbol_name; + elfcpp::STT enclosing_symbol_type; +}; + +// Data about a single relocation section. This is read in +// read_relocs and processed in scan_relocs. + +struct Section_relocs +{ + Section_relocs() + : contents(NULL) + { } + + ~Section_relocs() + { delete this->contents; } + + // Index of reloc section. + unsigned int reloc_shndx; + // Index of section that relocs apply to. + unsigned int data_shndx; + // Contents of reloc section. + File_view* contents; + // Reloc section type. + unsigned int sh_type; + // Number of reloc entries. + size_t reloc_count; + // Output section. + Output_section* output_section; + // Whether this section has special handling for offsets. + bool needs_special_offset_handling; + // Whether the data section is allocated (has the SHF_ALLOC flag set). + bool is_data_section_allocated; +}; + +// Relocations in an object file. This is read in read_relocs and +// processed in scan_relocs. + +struct Read_relocs_data +{ + Read_relocs_data() + : local_symbols(NULL) + { } + + ~Read_relocs_data() + { delete this->local_symbols; } + + typedef std::vector<Section_relocs> Relocs_list; + // The relocations. + Relocs_list relocs; + // The local symbols. + File_view* local_symbols; +}; + +// The Xindex class manages section indexes for objects with more than +// 0xff00 sections. + +class Xindex +{ + public: + Xindex(int large_shndx_offset) + : large_shndx_offset_(large_shndx_offset), symtab_xindex_() + { } + + // Initialize the symtab_xindex_ array, given the object and the + // section index of the symbol table to use. + template<int size, bool big_endian> + void + initialize_symtab_xindex(Object*, unsigned int symtab_shndx); + + // Read in the symtab_xindex_ array, given its section index. + // PSHDRS may optionally point to the section headers. + template<int size, bool big_endian> + void + read_symtab_xindex(Object*, unsigned int xindex_shndx, + const unsigned char* pshdrs); + + // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the + // real section index. + unsigned int + sym_xindex_to_shndx(Object* object, unsigned int symndx); + + private: + // The type of the array giving the real section index for symbols + // whose st_shndx field holds SHN_XINDEX. + typedef std::vector<unsigned int> Symtab_xindex; + + // Adjust a section index if necessary. This should only be called + // for ordinary section indexes. + unsigned int + adjust_shndx(unsigned int shndx) + { + if (shndx >= elfcpp::SHN_LORESERVE) + shndx += this->large_shndx_offset_; + return shndx; + } + + // Adjust to apply to large section indexes. + int large_shndx_offset_; + // The data from the SHT_SYMTAB_SHNDX section. + Symtab_xindex symtab_xindex_; +}; + +// A GOT offset list. A symbol may have more than one GOT offset +// (e.g., when mixing modules compiled with two different TLS models), +// but will usually have at most one. GOT_TYPE identifies the type of +// GOT entry; its values are specific to each target. + +class Got_offset_list +{ + public: + Got_offset_list() + : got_type_(-1U), got_offset_(0), got_next_(NULL) + { } + + Got_offset_list(unsigned int got_type, unsigned int got_offset) + : got_type_(got_type), got_offset_(got_offset), got_next_(NULL) + { } + + ~Got_offset_list() + { + if (this->got_next_ != NULL) + { + delete this->got_next_; + this->got_next_ = NULL; + } + } + + // Initialize the fields to their default values. + void + init() + { + this->got_type_ = -1U; + this->got_offset_ = 0; + this->got_next_ = NULL; + } + + // Set the offset for the GOT entry of type GOT_TYPE. + void + set_offset(unsigned int got_type, unsigned int got_offset) + { + if (this->got_type_ == -1U) + { + this->got_type_ = got_type; + this->got_offset_ = got_offset; + } + else + { + for (Got_offset_list* g = this; g != NULL; g = g->got_next_) + { + if (g->got_type_ == got_type) + { + g->got_offset_ = got_offset; + return; + } + } + Got_offset_list* g = new Got_offset_list(got_type, got_offset); + g->got_next_ = this->got_next_; + this->got_next_ = g; + } + } + + // Return the offset for a GOT entry of type GOT_TYPE. + unsigned int + get_offset(unsigned int got_type) const + { + for (const Got_offset_list* g = this; g != NULL; g = g->got_next_) + { + if (g->got_type_ == got_type) + return g->got_offset_; + } + return -1U; + } + + // Return a pointer to the list, or NULL if the list is empty. + const Got_offset_list* + get_list() const + { + if (this->got_type_ == -1U) + return NULL; + return this; + } + + // Abstract visitor class for iterating over GOT offsets. + class Visitor + { + public: + Visitor() + { } + + virtual + ~Visitor() + { } + + virtual void + visit(unsigned int, unsigned int) = 0; + }; + + // Loop over all GOT offset entries, calling a visitor class V for each. + void + for_all_got_offsets(Visitor* v) const + { + if (this->got_type_ == -1U) + return; + for (const Got_offset_list* g = this; g != NULL; g = g->got_next_) + v->visit(g->got_type_, g->got_offset_); + } + + private: + unsigned int got_type_; + unsigned int got_offset_; + Got_offset_list* got_next_; +}; + +// Object is an abstract base class which represents either a 32-bit +// or a 64-bit input object. This can be a regular object file +// (ET_REL) or a shared object (ET_DYN). + +class Object +{ + public: + typedef std::vector<Symbol*> Symbols; + + // NAME is the name of the object as we would report it to the user + // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is + // used to read the file. OFFSET is the offset within the input + // file--0 for a .o or .so file, something else for a .a file. + Object(const std::string& name, Input_file* input_file, bool is_dynamic, + off_t offset = 0) + : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U), + is_dynamic_(is_dynamic), is_needed_(false), uses_split_stack_(false), + has_no_split_stack_(false), no_export_(false), + is_in_system_directory_(false), as_needed_(false), xindex_(NULL) + { + if (input_file != NULL) + { + input_file->file().add_object(); + this->is_in_system_directory_ = input_file->is_in_system_directory(); + this->as_needed_ = input_file->options().as_needed(); + } + } + + virtual ~Object() + { + if (this->input_file_ != NULL) + this->input_file_->file().remove_object(); + } + + // Return the name of the object as we would report it to the user. + const std::string& + name() const + { return this->name_; } + + // Get the offset into the file. + off_t + offset() const + { return this->offset_; } + + // Return whether this is a dynamic object. + bool + is_dynamic() const + { return this->is_dynamic_; } + + // Return whether this object is needed--true if it is a dynamic + // object which defines some symbol referenced by a regular object. + // We keep the flag here rather than in Dynobj for convenience when + // setting it. + bool + is_needed() const + { return this->is_needed_; } + + // Record that this object is needed. + void + set_is_needed() + { this->is_needed_ = true; } + + // Return whether this object was compiled with -fsplit-stack. + bool + uses_split_stack() const + { return this->uses_split_stack_; } + + // Return whether this object contains any functions compiled with + // the no_split_stack attribute. + bool + has_no_split_stack() const + { return this->has_no_split_stack_; } + + // Returns NULL for Objects that are not dynamic objects. This method + // is overridden in the Dynobj class. + Dynobj* + dynobj() + { return this->do_dynobj(); } + + // Returns NULL for Objects that are not plugin objects. This method + // is overridden in the Pluginobj class. + Pluginobj* + pluginobj() + { return this->do_pluginobj(); } + + // Get the file. We pass on const-ness. + Input_file* + input_file() + { + gold_assert(this->input_file_ != NULL); + return this->input_file_; + } + + const Input_file* + input_file() const + { + gold_assert(this->input_file_ != NULL); + return this->input_file_; + } + + // Lock the underlying file. + void + lock(const Task* t) + { + if (this->input_file_ != NULL) + this->input_file_->file().lock(t); + } + + // Unlock the underlying file. + void + unlock(const Task* t) + { + if (this->input_file_ != NULL) + this->input_file()->file().unlock(t); + } + + // Return whether the underlying file is locked. + bool + is_locked() const + { return this->input_file_ != NULL && this->input_file_->file().is_locked(); } + + // Return the token, so that the task can be queued. + Task_token* + token() + { + if (this->input_file_ == NULL) + return NULL; + return this->input_file()->file().token(); + } + + // Release the underlying file. + void + release() + { + if (this->input_file_ != NULL) + this->input_file()->file().release(); + } + + // Return whether we should just read symbols from this file. + bool + just_symbols() const + { return this->input_file()->just_symbols(); } + + // Return whether this is an incremental object. + bool + is_incremental() const + { return this->do_is_incremental(); } + + // Return the last modified time of the file. + Timespec + get_mtime() + { return this->do_get_mtime(); } + + // Get the number of sections. + unsigned int + shnum() const + { return this->shnum_; } + + // Return a view of the contents of a section. Set *PLEN to the + // size. CACHE is a hint as in File_read::get_view. + const unsigned char* + section_contents(unsigned int shndx, section_size_type* plen, bool cache); + + // Adjust a symbol's section index as needed. SYMNDX is the index + // of the symbol and SHNDX is the symbol's section from + // get_st_shndx. This returns the section index. It sets + // *IS_ORDINARY to indicate whether this is a normal section index, + // rather than a special code between SHN_LORESERVE and + // SHN_HIRESERVE. + unsigned int + adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary) + { + if (shndx < elfcpp::SHN_LORESERVE) + *is_ordinary = true; + else if (shndx == elfcpp::SHN_XINDEX) + { + if (this->xindex_ == NULL) + this->xindex_ = this->do_initialize_xindex(); + shndx = this->xindex_->sym_xindex_to_shndx(this, symndx); + *is_ordinary = true; + } + else + *is_ordinary = false; + return shndx; + } + + // Return the size of a section given a section index. + uint64_t + section_size(unsigned int shndx) + { return this->do_section_size(shndx); } + + // Return the name of a section given a section index. + std::string + section_name(unsigned int shndx) + { return this->do_section_name(shndx); } + + // Return the section flags given a section index. + uint64_t + section_flags(unsigned int shndx) + { return this->do_section_flags(shndx); } + + // Return the section entsize given a section index. + uint64_t + section_entsize(unsigned int shndx) + { return this->do_section_entsize(shndx); } + + // Return the section address given a section index. + uint64_t + section_address(unsigned int shndx) + { return this->do_section_address(shndx); } + + // Return the section type given a section index. + unsigned int + section_type(unsigned int shndx) + { return this->do_section_type(shndx); } + + // Return the section link field given a section index. + unsigned int + section_link(unsigned int shndx) + { return this->do_section_link(shndx); } + + // Return the section info field given a section index. + unsigned int + section_info(unsigned int shndx) + { return this->do_section_info(shndx); } + + // Return the required section alignment given a section index. + uint64_t + section_addralign(unsigned int shndx) + { return this->do_section_addralign(shndx); } + + // Return the output section given a section index. + Output_section* + output_section(unsigned int shndx) const + { return this->do_output_section(shndx); } + + // Given a section index, return its address. + // The return value will be -1U if the section is specially mapped, + // such as a merge section. + uint64_t + output_section_address(unsigned int shndx) + { return this->do_output_section_address(shndx); } + + // Given a section index, return the offset in the Output_section. + // The return value will be -1U if the section is specially mapped, + // such as a merge section. + uint64_t + output_section_offset(unsigned int shndx) const + { return this->do_output_section_offset(shndx); } + + // Read the symbol information. + void + read_symbols(Read_symbols_data* sd) + { return this->do_read_symbols(sd); } + + // Pass sections which should be included in the link to the Layout + // object, and record where the sections go in the output file. + void + layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd) + { this->do_layout(symtab, layout, sd); } + + // Add symbol information to the global symbol table. + void + add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout) + { this->do_add_symbols(symtab, sd, layout); } + + // Add symbol information to the global symbol table. + Archive::Should_include + should_include_member(Symbol_table* symtab, Layout* layout, + Read_symbols_data* sd, std::string* why) + { return this->do_should_include_member(symtab, layout, sd, why); } + + // Iterate over global symbols, calling a visitor class V for each. + void + for_all_global_symbols(Read_symbols_data* sd, + Library_base::Symbol_visitor_base* v) + { return this->do_for_all_global_symbols(sd, v); } + + // Iterate over local symbols, calling a visitor class V for each GOT offset + // associated with a local symbol. + void + for_all_local_got_entries(Got_offset_list::Visitor* v) const + { this->do_for_all_local_got_entries(v); } + + // Functions and types for the elfcpp::Elf_file interface. This + // permit us to use Object as the File template parameter for + // elfcpp::Elf_file. + + // The View class is returned by view. It must support a single + // method, data(). This is trivial, because get_view does what we + // need. + class View + { + public: + View(const unsigned char* p) + : p_(p) + { } + + const unsigned char* + data() const + { return this->p_; } + + private: + const unsigned char* p_; + }; + + // Return a View. + View + view(off_t file_offset, section_size_type data_size) + { return View(this->get_view(file_offset, data_size, true, true)); } + + // Report an error. + void + error(const char* format, ...) const ATTRIBUTE_PRINTF_2; + + // A location in the file. + struct Location + { + off_t file_offset; + off_t data_size; + + Location(off_t fo, section_size_type ds) + : file_offset(fo), data_size(ds) + { } + }; + + // Get a View given a Location. + View view(Location loc) + { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); } + + // Get a view into the underlying file. + const unsigned char* + get_view(off_t start, section_size_type size, bool aligned, bool cache) + { + return this->input_file()->file().get_view(this->offset_, start, size, + aligned, cache); + } + + // Get a lasting view into the underlying file. + File_view* + get_lasting_view(off_t start, section_size_type size, bool aligned, + bool cache) + { + return this->input_file()->file().get_lasting_view(this->offset_, start, + size, aligned, cache); + } + + // Read data from the underlying file. + void + read(off_t start, section_size_type size, void* p) + { this->input_file()->file().read(start + this->offset_, size, p); } + + // Read multiple data from the underlying file. + void + read_multiple(const File_read::Read_multiple& rm) + { this->input_file()->file().read_multiple(this->offset_, rm); } + + // Stop caching views in the underlying file. + void + clear_view_cache_marks() + { + if (this->input_file_ != NULL) + this->input_file_->file().clear_view_cache_marks(); + } + + // Get the number of global symbols defined by this object, and the + // number of the symbols whose final definition came from this + // object. + void + get_global_symbol_counts(const Symbol_table* symtab, size_t* defined, + size_t* used) const + { this->do_get_global_symbol_counts(symtab, defined, used); } + + // Get the symbols defined in this object. + const Symbols* + get_global_symbols() const + { return this->do_get_global_symbols(); } + + // Set flag that this object was found in a system directory. + void + set_is_in_system_directory() + { this->is_in_system_directory_ = true; } + + // Return whether this object was found in a system directory. + bool + is_in_system_directory() const + { return this->is_in_system_directory_; } + + // Set flag that this object was linked with --as-needed. + void + set_as_needed() + { this->as_needed_ = true; } + + // Return whether this object was linked with --as-needed. + bool + as_needed() const + { return this->as_needed_; } + + // Return whether we found this object by searching a directory. + bool + searched_for() const + { return this->input_file()->will_search_for(); } + + bool + no_export() const + { return this->no_export_; } + + void + set_no_export(bool value) + { this->no_export_ = value; } + + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + bool + section_is_compressed(unsigned int shndx, + section_size_type* uncompressed_size) const + { return this->do_section_is_compressed(shndx, uncompressed_size); } + + // Return a view of the decompressed contents of a section. Set *PLEN + // to the size. Set *IS_NEW to true if the contents need to be freed + // by the caller. + const unsigned char* + decompressed_section_contents(unsigned int shndx, section_size_type* plen, + bool* is_cached) + { return this->do_decompressed_section_contents(shndx, plen, is_cached); } + + // Discard any buffers of decompressed sections. This is done + // at the end of the Add_symbols task. + void + discard_decompressed_sections() + { this->do_discard_decompressed_sections(); } + + // Return the index of the first incremental relocation for symbol SYMNDX. + unsigned int + get_incremental_reloc_base(unsigned int symndx) const + { return this->do_get_incremental_reloc_base(symndx); } + + // Return the number of incremental relocations for symbol SYMNDX. + unsigned int + get_incremental_reloc_count(unsigned int symndx) const + { return this->do_get_incremental_reloc_count(symndx); } + + protected: + // Returns NULL for Objects that are not dynamic objects. This method + // is overridden in the Dynobj class. + virtual Dynobj* + do_dynobj() + { return NULL; } + + // Returns NULL for Objects that are not plugin objects. This method + // is overridden in the Pluginobj class. + virtual Pluginobj* + do_pluginobj() + { return NULL; } + + // Return TRUE if this is an incremental (unchanged) input file. + // We return FALSE by default; the incremental object classes + // override this method. + virtual bool + do_is_incremental() const + { return false; } + + // Return the last modified time of the file. This method may be + // overridden for subclasses that don't use an actual file (e.g., + // Incremental objects). + virtual Timespec + do_get_mtime() + { return this->input_file()->file().get_mtime(); } + + // Read the symbols--implemented by child class. + virtual void + do_read_symbols(Read_symbols_data*) = 0; + + // Lay out sections--implemented by child class. + virtual void + do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0; + + // Add symbol information to the global symbol table--implemented by + // child class. + virtual void + do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0; + + virtual Archive::Should_include + do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*, + std::string* why) = 0; + + // Iterate over global symbols, calling a visitor class V for each. + virtual void + do_for_all_global_symbols(Read_symbols_data* sd, + Library_base::Symbol_visitor_base* v) = 0; + + // Iterate over local symbols, calling a visitor class V for each GOT offset + // associated with a local symbol. + virtual void + do_for_all_local_got_entries(Got_offset_list::Visitor* v) const = 0; + + // Return the location of the contents of a section. Implemented by + // child class. + virtual const unsigned char* + do_section_contents(unsigned int shndx, section_size_type* plen, + bool cache) = 0; + + // Get the size of a section--implemented by child class. + virtual uint64_t + do_section_size(unsigned int shndx) = 0; + + // Get the name of a section--implemented by child class. + virtual std::string + do_section_name(unsigned int shndx) = 0; + + // Get section flags--implemented by child class. + virtual uint64_t + do_section_flags(unsigned int shndx) = 0; + + // Get section entsize--implemented by child class. + virtual uint64_t + do_section_entsize(unsigned int shndx) = 0; + + // Get section address--implemented by child class. + virtual uint64_t + do_section_address(unsigned int shndx) = 0; + + // Get section type--implemented by child class. + virtual unsigned int + do_section_type(unsigned int shndx) = 0; + + // Get section link field--implemented by child class. + virtual unsigned int + do_section_link(unsigned int shndx) = 0; + + // Get section info field--implemented by child class. + virtual unsigned int + do_section_info(unsigned int shndx) = 0; + + // Get section alignment--implemented by child class. + virtual uint64_t + do_section_addralign(unsigned int shndx) = 0; + + // Return the output section given a section index--implemented + // by child class. + virtual Output_section* + do_output_section(unsigned int) const + { gold_unreachable(); } + + // Get the address of a section--implemented by child class. + virtual uint64_t + do_output_section_address(unsigned int) + { gold_unreachable(); } + + // Get the offset of a section--implemented by child class. + virtual uint64_t + do_output_section_offset(unsigned int) const + { gold_unreachable(); } + + // Return the Xindex structure to use. + virtual Xindex* + do_initialize_xindex() = 0; + + // Implement get_global_symbol_counts--implemented by child class. + virtual void + do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const = 0; + + virtual const Symbols* + do_get_global_symbols() const = 0; + + // Set the number of sections. + void + set_shnum(int shnum) + { this->shnum_ = shnum; } + + // Functions used by both Sized_relobj_file and Sized_dynobj. + + // Read the section data into a Read_symbols_data object. + template<int size, bool big_endian> + void + read_section_data(elfcpp::Elf_file<size, big_endian, Object>*, + Read_symbols_data*); + + // Find the section header with the given NAME. If HDR is non-NULL + // then it is a section header returned from a previous call to this + // function and the next section header with the same name will be + // returned. + template<int size, bool big_endian> + const unsigned char* + find_shdr(const unsigned char* pshdrs, const char* name, + const char* names, section_size_type names_size, + const unsigned char* hdr) const; + + // Let the child class initialize the xindex object directly. + void + set_xindex(Xindex* xindex) + { + gold_assert(this->xindex_ == NULL); + this->xindex_ = xindex; + } + + // If NAME is the name of a special .gnu.warning section, arrange + // for the warning to be issued. SHNDX is the section index. + // Return whether it is a warning section. + bool + handle_gnu_warning_section(const char* name, unsigned int shndx, + Symbol_table*); + + // If NAME is the name of the special section which indicates that + // this object was compiled with -fsplit-stack, mark it accordingly, + // and return true. Otherwise return false. + bool + handle_split_stack_section(const char* name); + + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + virtual bool + do_section_is_compressed(unsigned int, section_size_type*) const + { return false; } + + // Return a view of the decompressed contents of a section. Set *PLEN + // to the size. This default implementation simply returns the + // raw section contents and sets *IS_NEW to false to indicate + // that the contents do not need to be freed by the caller. + // This function must be overridden for any types of object files + // that might contain compressed sections. + virtual const unsigned char* + do_decompressed_section_contents(unsigned int shndx, + section_size_type* plen, + bool* is_new) + { + *is_new = false; + return this->do_section_contents(shndx, plen, false); + } + + // Discard any buffers of decompressed sections. This is done + // at the end of the Add_symbols task. + virtual void + do_discard_decompressed_sections() + { } + + // Return the index of the first incremental relocation for symbol SYMNDX-- + // implemented by child class. + virtual unsigned int + do_get_incremental_reloc_base(unsigned int) const + { gold_unreachable(); } + + // Return the number of incremental relocations for symbol SYMNDX-- + // implemented by child class. + virtual unsigned int + do_get_incremental_reloc_count(unsigned int) const + { gold_unreachable(); } + + private: + // This class may not be copied. + Object(const Object&); + Object& operator=(const Object&); + + // Name of object as printed to user. + std::string name_; + // For reading the file. + Input_file* input_file_; + // Offset within the file--0 for an object file, non-0 for an + // archive. + off_t offset_; + // Number of input sections. + unsigned int shnum_; + // Whether this is a dynamic object. + bool is_dynamic_ : 1; + // Whether this object is needed. This is only set for dynamic + // objects, and means that the object defined a symbol which was + // used by a reference from a regular object. + bool is_needed_ : 1; + // Whether this object was compiled with -fsplit-stack. + bool uses_split_stack_ : 1; + // Whether this object contains any functions compiled with the + // no_split_stack attribute. + bool has_no_split_stack_ : 1; + // True if exclude this object from automatic symbol export. + // This is used only for archive objects. + bool no_export_ : 1; + // True if the object was found in a system directory. + bool is_in_system_directory_ : 1; + // True if the object was linked with --as-needed. + bool as_needed_ : 1; + // Many sections for objects with more than SHN_LORESERVE sections. + Xindex* xindex_; +}; + +// A regular object (ET_REL). This is an abstract base class itself. +// The implementation is the template class Sized_relobj_file. + +class Relobj : public Object +{ + public: + Relobj(const std::string& name, Input_file* input_file, off_t offset = 0) + : Object(name, input_file, false, offset), + output_sections_(), + map_to_relocatable_relocs_(NULL), + object_merge_map_(NULL), + relocs_must_follow_section_writes_(false), + sd_(NULL), + reloc_counts_(NULL), + reloc_bases_(NULL), + first_dyn_reloc_(0), + dyn_reloc_count_(0) + { } + + // During garbage collection, the Read_symbols_data pass for + // each object is stored as layout needs to be done after + // reloc processing. + Symbols_data* + get_symbols_data() + { return this->sd_; } + + // Decides which section names have to be included in the worklist + // as roots. + bool + is_section_name_included(const char* name); + + void + copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd, + unsigned int section_header_size); + + void + set_symbols_data(Symbols_data* sd) + { this->sd_ = sd; } + + // During garbage collection, the Read_relocs pass for all objects + // is done before scanning the relocs. In that case, this->rd_ is + // used to store the information from Read_relocs for each object. + // This data is also used to compute the list of relevant sections. + Read_relocs_data* + get_relocs_data() + { return this->rd_; } + + void + set_relocs_data(Read_relocs_data* rd) + { this->rd_ = rd; } + + virtual bool + is_output_section_offset_invalid(unsigned int shndx) const = 0; + + // Read the relocs. + void + read_relocs(Read_relocs_data* rd) + { return this->do_read_relocs(rd); } + + // Process the relocs, during garbage collection only. + void + gc_process_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd) + { return this->do_gc_process_relocs(symtab, layout, rd); } + + // Scan the relocs and adjust the symbol table. + void + scan_relocs(Symbol_table* symtab, Layout* layout, Read_relocs_data* rd) + { return this->do_scan_relocs(symtab, layout, rd); } + + // Return the value of the local symbol whose index is SYMNDX, plus + // ADDEND. ADDEND is passed in so that we can correctly handle the + // section symbol for a merge section. + uint64_t + local_symbol_value(unsigned int symndx, uint64_t addend) const + { return this->do_local_symbol_value(symndx, addend); } + + // Return the PLT offset for a local symbol. It is an error to call + // this if it doesn't have one. + unsigned int + local_plt_offset(unsigned int symndx) const + { return this->do_local_plt_offset(symndx); } + + // Return whether the local symbol SYMNDX has a GOT offset of type + // GOT_TYPE. + bool + local_has_got_offset(unsigned int symndx, unsigned int got_type) const + { return this->do_local_has_got_offset(symndx, got_type); } + + // Return the GOT offset of type GOT_TYPE of the local symbol + // SYMNDX. It is an error to call this if the symbol does not have + // a GOT offset of the specified type. + unsigned int + local_got_offset(unsigned int symndx, unsigned int got_type) const + { return this->do_local_got_offset(symndx, got_type); } + + // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX + // to GOT_OFFSET. + void + set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset) + { this->do_set_local_got_offset(symndx, got_type, got_offset); } + + // Return whether the local symbol SYMNDX is a TLS symbol. + bool + local_is_tls(unsigned int symndx) const + { return this->do_local_is_tls(symndx); } + + // The number of local symbols in the input symbol table. + virtual unsigned int + local_symbol_count() const + { return this->do_local_symbol_count(); } + + // The number of local symbols in the output symbol table. + virtual unsigned int + output_local_symbol_count() const + { return this->do_output_local_symbol_count(); } + + // The file offset for local symbols in the output symbol table. + virtual off_t + local_symbol_offset() const + { return this->do_local_symbol_offset(); } + + // Initial local symbol processing: count the number of local symbols + // in the output symbol table and dynamic symbol table; add local symbol + // names to *POOL and *DYNPOOL. + void + count_local_symbols(Stringpool_template<char>* pool, + Stringpool_template<char>* dynpool) + { return this->do_count_local_symbols(pool, dynpool); } + + // Set the values of the local symbols, set the output symbol table + // indexes for the local variables, and set the offset where local + // symbol information will be stored. Returns the new local symbol index. + unsigned int + finalize_local_symbols(unsigned int index, off_t off, Symbol_table* symtab) + { return this->do_finalize_local_symbols(index, off, symtab); } + + // Set the output dynamic symbol table indexes for the local variables. + unsigned int + set_local_dynsym_indexes(unsigned int index) + { return this->do_set_local_dynsym_indexes(index); } + + // Set the offset where local dynamic symbol information will be stored. + unsigned int + set_local_dynsym_offset(off_t off) + { return this->do_set_local_dynsym_offset(off); } + + // Record a dynamic relocation against an input section from this object. + void + add_dyn_reloc(unsigned int index) + { + if (this->dyn_reloc_count_ == 0) + this->first_dyn_reloc_ = index; + ++this->dyn_reloc_count_; + } + + // Return the index of the first dynamic relocation. + unsigned int + first_dyn_reloc() const + { return this->first_dyn_reloc_; } + + // Return the count of dynamic relocations. + unsigned int + dyn_reloc_count() const + { return this->dyn_reloc_count_; } + + // Relocate the input sections and write out the local symbols. + void + relocate(const Symbol_table* symtab, const Layout* layout, Output_file* of) + { return this->do_relocate(symtab, layout, of); } + + // Return whether an input section is being included in the link. + bool + is_section_included(unsigned int shndx) const + { + gold_assert(shndx < this->output_sections_.size()); + return this->output_sections_[shndx] != NULL; + } + + // The output section of the input section with index SHNDX. + // This is only used currently to remove a section from the link in + // relaxation. + void + set_output_section(unsigned int shndx, Output_section* os) + { + gold_assert(shndx < this->output_sections_.size()); + this->output_sections_[shndx] = os; + } + + // Set the offset of an input section within its output section. + void + set_section_offset(unsigned int shndx, uint64_t off) + { this->do_set_section_offset(shndx, off); } + + // Return true if we need to wait for output sections to be written + // before we can apply relocations. This is true if the object has + // any relocations for sections which require special handling, such + // as the exception frame section. + bool + relocs_must_follow_section_writes() const + { return this->relocs_must_follow_section_writes_; } + + // Return the object merge map. + Object_merge_map* + merge_map() const + { return this->object_merge_map_; } + + // Set the object merge map. + void + set_merge_map(Object_merge_map* object_merge_map) + { + gold_assert(this->object_merge_map_ == NULL); + this->object_merge_map_ = object_merge_map; + } + + // Record the relocatable reloc info for an input reloc section. + void + set_relocatable_relocs(unsigned int reloc_shndx, Relocatable_relocs* rr) + { + gold_assert(reloc_shndx < this->shnum()); + (*this->map_to_relocatable_relocs_)[reloc_shndx] = rr; + } + + // Get the relocatable reloc info for an input reloc section. + Relocatable_relocs* + relocatable_relocs(unsigned int reloc_shndx) + { + gold_assert(reloc_shndx < this->shnum()); + return (*this->map_to_relocatable_relocs_)[reloc_shndx]; + } + + // Layout sections whose layout was deferred while waiting for + // input files from a plugin. + void + layout_deferred_sections(Layout* layout) + { this->do_layout_deferred_sections(layout); } + + // Return the index of the first incremental relocation for symbol SYMNDX. + virtual unsigned int + do_get_incremental_reloc_base(unsigned int symndx) const + { return this->reloc_bases_[symndx]; } + + // Return the number of incremental relocations for symbol SYMNDX. + virtual unsigned int + do_get_incremental_reloc_count(unsigned int symndx) const + { return this->reloc_counts_[symndx]; } + + // Return the word size of the object file. + int + elfsize() const + { return this->do_elfsize(); } + + // Return TRUE if this is a big-endian object file. + bool + is_big_endian() const + { return this->do_is_big_endian(); } + + protected: + // The output section to be used for each input section, indexed by + // the input section number. The output section is NULL if the + // input section is to be discarded. + typedef std::vector<Output_section*> Output_sections; + + // Read the relocs--implemented by child class. + virtual void + do_read_relocs(Read_relocs_data*) = 0; + + // Process the relocs--implemented by child class. + virtual void + do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0; + + // Scan the relocs--implemented by child class. + virtual void + do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*) = 0; + + // Return the value of a local symbol. + virtual uint64_t + do_local_symbol_value(unsigned int symndx, uint64_t addend) const = 0; + + // Return the PLT offset of a local symbol. + virtual unsigned int + do_local_plt_offset(unsigned int symndx) const = 0; + + // Return whether a local symbol has a GOT offset of a given type. + virtual bool + do_local_has_got_offset(unsigned int symndx, + unsigned int got_type) const = 0; + + // Return the GOT offset of a given type of a local symbol. + virtual unsigned int + do_local_got_offset(unsigned int symndx, unsigned int got_type) const = 0; + + // Set the GOT offset with a given type for a local symbol. + virtual void + do_set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset) = 0; + + // Return whether local symbol SYMNDX is a TLS symbol. + virtual bool + do_local_is_tls(unsigned int symndx) const = 0; + + // Return the number of local symbols--implemented by child class. + virtual unsigned int + do_local_symbol_count() const = 0; + + // Return the number of output local symbols--implemented by child class. + virtual unsigned int + do_output_local_symbol_count() const = 0; + + // Return the file offset for local symbols--implemented by child class. + virtual off_t + do_local_symbol_offset() const = 0; + + // Count local symbols--implemented by child class. + virtual void + do_count_local_symbols(Stringpool_template<char>*, + Stringpool_template<char>*) = 0; + + // Finalize the local symbols. Set the output symbol table indexes + // for the local variables, and set the offset where local symbol + // information will be stored. + virtual unsigned int + do_finalize_local_symbols(unsigned int, off_t, Symbol_table*) = 0; + + // Set the output dynamic symbol table indexes for the local variables. + virtual unsigned int + do_set_local_dynsym_indexes(unsigned int) = 0; + + // Set the offset where local dynamic symbol information will be stored. + virtual unsigned int + do_set_local_dynsym_offset(off_t) = 0; + + // Relocate the input sections and write out the local + // symbols--implemented by child class. + virtual void + do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of) = 0; + + // Set the offset of a section--implemented by child class. + virtual void + do_set_section_offset(unsigned int shndx, uint64_t off) = 0; + + // Layout sections whose layout was deferred while waiting for + // input files from a plugin--implemented by child class. + virtual void + do_layout_deferred_sections(Layout*) = 0; + + // Given a section index, return the corresponding Output_section. + // The return value will be NULL if the section is not included in + // the link. + Output_section* + do_output_section(unsigned int shndx) const + { + gold_assert(shndx < this->output_sections_.size()); + return this->output_sections_[shndx]; + } + + // Return the vector mapping input sections to output sections. + Output_sections& + output_sections() + { return this->output_sections_; } + + const Output_sections& + output_sections() const + { return this->output_sections_; } + + // Set the size of the relocatable relocs array. + void + size_relocatable_relocs() + { + this->map_to_relocatable_relocs_ = + new std::vector<Relocatable_relocs*>(this->shnum()); + } + + // Record that we must wait for the output sections to be written + // before applying relocations. + void + set_relocs_must_follow_section_writes() + { this->relocs_must_follow_section_writes_ = true; } + + // Allocate the array for counting incremental relocations. + void + allocate_incremental_reloc_counts() + { + unsigned int nsyms = this->do_get_global_symbols()->size(); + this->reloc_counts_ = new unsigned int[nsyms]; + gold_assert(this->reloc_counts_ != NULL); + memset(this->reloc_counts_, 0, nsyms * sizeof(unsigned int)); + } + + // Record a relocation in this object referencing global symbol SYMNDX. + // Used for tracking incremental link information. + void + count_incremental_reloc(unsigned int symndx) + { + unsigned int nsyms = this->do_get_global_symbols()->size(); + gold_assert(symndx < nsyms); + gold_assert(this->reloc_counts_ != NULL); + ++this->reloc_counts_[symndx]; + } + + // Finalize the incremental relocation information. + void + finalize_incremental_relocs(Layout* layout, bool clear_counts); + + // Return the index of the next relocation to be written for global symbol + // SYMNDX. Only valid after finalize_incremental_relocs() has been called. + unsigned int + next_incremental_reloc_index(unsigned int symndx) + { + unsigned int nsyms = this->do_get_global_symbols()->size(); + + gold_assert(this->reloc_counts_ != NULL); + gold_assert(this->reloc_bases_ != NULL); + gold_assert(symndx < nsyms); + + unsigned int counter = this->reloc_counts_[symndx]++; + return this->reloc_bases_[symndx] + counter; + } + + // Return the word size of the object file-- + // implemented by child class. + virtual int + do_elfsize() const = 0; + + // Return TRUE if this is a big-endian object file-- + // implemented by child class. + virtual bool + do_is_big_endian() const = 0; + + private: + // Mapping from input sections to output section. + Output_sections output_sections_; + // Mapping from input section index to the information recorded for + // the relocations. This is only used for a relocatable link. + std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_; + // Mappings for merge sections. This is managed by the code in the + // Merge_map class. + Object_merge_map* object_merge_map_; + // Whether we need to wait for output sections to be written before + // we can apply relocations. + bool relocs_must_follow_section_writes_; + // Used to store the relocs data computed by the Read_relocs pass. + // Used during garbage collection of unused sections. + Read_relocs_data* rd_; + // Used to store the symbols data computed by the Read_symbols pass. + // Again used during garbage collection when laying out referenced + // sections. + gold::Symbols_data* sd_; + // Per-symbol counts of relocations, for incremental links. + unsigned int* reloc_counts_; + // Per-symbol base indexes of relocations, for incremental links. + unsigned int* reloc_bases_; + // Index of the first dynamic relocation for this object. + unsigned int first_dyn_reloc_; + // Count of dynamic relocations for this object. + unsigned int dyn_reloc_count_; +}; + +// This class is used to handle relocations against a section symbol +// in an SHF_MERGE section. For such a symbol, we need to know the +// addend of the relocation before we can determine the final value. +// The addend gives us the location in the input section, and we can +// determine how it is mapped to the output section. For a +// non-section symbol, we apply the addend to the final value of the +// symbol; that is done in finalize_local_symbols, and does not use +// this class. + +template<int size> +class Merged_symbol_value +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Value; + + // We use a hash table to map offsets in the input section to output + // addresses. + typedef Unordered_map<section_offset_type, Value> Output_addresses; + + Merged_symbol_value(Value input_value, Value output_start_address) + : input_value_(input_value), output_start_address_(output_start_address), + output_addresses_() + { } + + // Initialize the hash table. + void + initialize_input_to_output_map(const Relobj*, unsigned int input_shndx); + + // Release the hash table to save space. + void + free_input_to_output_map() + { this->output_addresses_.clear(); } + + // Get the output value corresponding to an addend. The object and + // input section index are passed in because the caller will have + // them; otherwise we could store them here. + Value + value(const Relobj* object, unsigned int input_shndx, Value addend) const + { + // This is a relocation against a section symbol. ADDEND is the + // offset in the section. The result should be the start of some + // merge area. If the object file wants something else, it should + // use a regular symbol rather than a section symbol. + // Unfortunately, PR 6658 shows a case in which the object file + // refers to the section symbol, but uses a negative ADDEND to + // compensate for a PC relative reloc. We can't handle the + // general case. However, we can handle the special case of a + // negative addend, by assuming that it refers to the start of the + // section. Of course, that means that we have to guess when + // ADDEND is negative. It is normal to see a 32-bit value here + // even when the template parameter size is 64, as 64-bit object + // file formats have 32-bit relocations. We know this is a merge + // section, so we know it has to fit into memory. So we assume + // that we won't see a value larger than a large 32-bit unsigned + // value. This will break objects with very very large merge + // sections; they probably break in other ways anyhow. + Value input_offset = this->input_value_; + if (addend < 0xffffff00) + { + input_offset += addend; + addend = 0; + } + typename Output_addresses::const_iterator p = + this->output_addresses_.find(input_offset); + if (p != this->output_addresses_.end()) + return p->second + addend; + + return (this->value_from_output_section(object, input_shndx, input_offset) + + addend); + } + + private: + // Get the output value for an input offset if we couldn't find it + // in the hash table. + Value + value_from_output_section(const Relobj*, unsigned int input_shndx, + Value input_offset) const; + + // The value of the section symbol in the input file. This is + // normally zero, but could in principle be something else. + Value input_value_; + // The start address of this merged section in the output file. + Value output_start_address_; + // A hash table which maps offsets in the input section to output + // addresses. This only maps specific offsets, not all offsets. + Output_addresses output_addresses_; +}; + +// This POD class is holds the value of a symbol. This is used for +// local symbols, and for all symbols during relocation processing. +// For special sections, such as SHF_MERGE sections, this calls a +// function to get the final symbol value. + +template<int size> +class Symbol_value +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Value; + + Symbol_value() + : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0), + is_ordinary_shndx_(false), is_section_symbol_(false), + is_tls_symbol_(false), is_ifunc_symbol_(false), has_output_value_(true) + { this->u_.value = 0; } + + ~Symbol_value() + { + if (!this->has_output_value_) + delete this->u_.merged_symbol_value; + } + + // Get the value of this symbol. OBJECT is the object in which this + // symbol is defined, and ADDEND is an addend to add to the value. + template<bool big_endian> + Value + value(const Sized_relobj_file<size, big_endian>* object, Value addend) const + { + if (this->has_output_value_) + return this->u_.value + addend; + else + { + gold_assert(this->is_ordinary_shndx_); + return this->u_.merged_symbol_value->value(object, this->input_shndx_, + addend); + } + } + + // Set the value of this symbol in the output symbol table. + void + set_output_value(Value value) + { this->u_.value = value; } + + // For a section symbol in a merged section, we need more + // information. + void + set_merged_symbol_value(Merged_symbol_value<size>* msv) + { + gold_assert(this->is_section_symbol_); + this->has_output_value_ = false; + this->u_.merged_symbol_value = msv; + } + + // Initialize the input to output map for a section symbol in a + // merged section. We also initialize the value of a non-section + // symbol in a merged section. + void + initialize_input_to_output_map(const Relobj* object) + { + if (!this->has_output_value_) + { + gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_); + Merged_symbol_value<size>* msv = this->u_.merged_symbol_value; + msv->initialize_input_to_output_map(object, this->input_shndx_); + } + } + + // Free the input to output map for a section symbol in a merged + // section. + void + free_input_to_output_map() + { + if (!this->has_output_value_) + this->u_.merged_symbol_value->free_input_to_output_map(); + } + + // Set the value of the symbol from the input file. This is only + // called by count_local_symbols, to communicate the value to + // finalize_local_symbols. + void + set_input_value(Value value) + { this->u_.value = value; } + + // Return the input value. This is only called by + // finalize_local_symbols and (in special cases) relocate_section. + Value + input_value() const + { return this->u_.value; } + + // Return whether we have set the index in the output symbol table + // yet. + bool + is_output_symtab_index_set() const + { + return (this->output_symtab_index_ != 0 + && this->output_symtab_index_ != -2U); + } + + // Return whether this symbol may be discarded from the normal + // symbol table. + bool + may_be_discarded_from_output_symtab() const + { + gold_assert(!this->is_output_symtab_index_set()); + return this->output_symtab_index_ != -2U; + } + + // Return whether this symbol has an entry in the output symbol + // table. + bool + has_output_symtab_entry() const + { + gold_assert(this->is_output_symtab_index_set()); + return this->output_symtab_index_ != -1U; + } + + // Return the index in the output symbol table. + unsigned int + output_symtab_index() const + { + gold_assert(this->is_output_symtab_index_set() + && this->output_symtab_index_ != -1U); + return this->output_symtab_index_; + } + + // Set the index in the output symbol table. + void + set_output_symtab_index(unsigned int i) + { + gold_assert(!this->is_output_symtab_index_set()); + gold_assert(i != 0 && i != -1U && i != -2U); + this->output_symtab_index_ = i; + } + + // Record that this symbol should not go into the output symbol + // table. + void + set_no_output_symtab_entry() + { + gold_assert(this->output_symtab_index_ == 0); + this->output_symtab_index_ = -1U; + } + + // Record that this symbol must go into the output symbol table, + // because it there is a relocation that uses it. + void + set_must_have_output_symtab_entry() + { + gold_assert(!this->is_output_symtab_index_set()); + this->output_symtab_index_ = -2U; + } + + // Set the index in the output dynamic symbol table. + void + set_needs_output_dynsym_entry() + { + gold_assert(!this->is_section_symbol()); + this->output_dynsym_index_ = 0; + } + + // Return whether this symbol should go into the dynamic symbol + // table. + bool + needs_output_dynsym_entry() const + { + return this->output_dynsym_index_ != -1U; + } + + // Return whether this symbol has an entry in the dynamic symbol + // table. + bool + has_output_dynsym_entry() const + { + gold_assert(this->output_dynsym_index_ != 0); + return this->output_dynsym_index_ != -1U; + } + + // Record that this symbol should go into the dynamic symbol table. + void + set_output_dynsym_index(unsigned int i) + { + gold_assert(this->output_dynsym_index_ == 0); + gold_assert(i != 0 && i != -1U); + this->output_dynsym_index_ = i; + } + + // Return the index in the output dynamic symbol table. + unsigned int + output_dynsym_index() const + { + gold_assert(this->output_dynsym_index_ != 0 + && this->output_dynsym_index_ != -1U); + return this->output_dynsym_index_; + } + + // Set the index of the input section in the input file. + void + set_input_shndx(unsigned int i, bool is_ordinary) + { + this->input_shndx_ = i; + // input_shndx_ field is a bitfield, so make sure that the value + // fits. + gold_assert(this->input_shndx_ == i); + this->is_ordinary_shndx_ = is_ordinary; + } + + // Return the index of the input section in the input file. + unsigned int + input_shndx(bool* is_ordinary) const + { + *is_ordinary = this->is_ordinary_shndx_; + return this->input_shndx_; + } + + // Whether this is a section symbol. + bool + is_section_symbol() const + { return this->is_section_symbol_; } + + // Record that this is a section symbol. + void + set_is_section_symbol() + { + gold_assert(!this->needs_output_dynsym_entry()); + this->is_section_symbol_ = true; + } + + // Record that this is a TLS symbol. + void + set_is_tls_symbol() + { this->is_tls_symbol_ = true; } + + // Return true if this is a TLS symbol. + bool + is_tls_symbol() const + { return this->is_tls_symbol_; } + + // Record that this is an IFUNC symbol. + void + set_is_ifunc_symbol() + { this->is_ifunc_symbol_ = true; } + + // Return true if this is an IFUNC symbol. + bool + is_ifunc_symbol() const + { return this->is_ifunc_symbol_; } + + // Return true if this has output value. + bool + has_output_value() const + { return this->has_output_value_; } + + private: + // The index of this local symbol in the output symbol table. This + // will be 0 if no value has been assigned yet, and the symbol may + // be omitted. This will be -1U if the symbol should not go into + // the symbol table. This will be -2U if the symbol must go into + // the symbol table, but no index has been assigned yet. + unsigned int output_symtab_index_; + // The index of this local symbol in the dynamic symbol table. This + // will be -1U if the symbol should not go into the symbol table. + unsigned int output_dynsym_index_; + // The section index in the input file in which this symbol is + // defined. + unsigned int input_shndx_ : 27; + // Whether the section index is an ordinary index, not a special + // value. + bool is_ordinary_shndx_ : 1; + // Whether this is a STT_SECTION symbol. + bool is_section_symbol_ : 1; + // Whether this is a STT_TLS symbol. + bool is_tls_symbol_ : 1; + // Whether this is a STT_GNU_IFUNC symbol. + bool is_ifunc_symbol_ : 1; + // Whether this symbol has a value for the output file. This is + // normally set to true during Layout::finalize, by + // finalize_local_symbols. It will be false for a section symbol in + // a merge section, as for such symbols we can not determine the + // value to use in a relocation until we see the addend. + bool has_output_value_ : 1; + union + { + // This is used if has_output_value_ is true. Between + // count_local_symbols and finalize_local_symbols, this is the + // value in the input file. After finalize_local_symbols, it is + // the value in the output file. + Value value; + // This is used if has_output_value_ is false. It points to the + // information we need to get the value for a merge section. + Merged_symbol_value<size>* merged_symbol_value; + } u_; +}; + +// This type is used to modify relocations for -fsplit-stack. It is +// indexed by relocation index, and means that the relocation at that +// index should use the symbol from the vector, rather than the one +// indicated by the relocation. + +class Reloc_symbol_changes +{ + public: + Reloc_symbol_changes(size_t count) + : vec_(count, NULL) + { } + + void + set(size_t i, Symbol* sym) + { this->vec_[i] = sym; } + + const Symbol* + operator[](size_t i) const + { return this->vec_[i]; } + + private: + std::vector<Symbol*> vec_; +}; + +// Type for mapping section index to uncompressed size and contents. + +struct Compressed_section_info +{ + section_size_type size; + const unsigned char* contents; +}; +typedef std::map<unsigned int, Compressed_section_info> Compressed_section_map; + +// Abstract base class for a regular object file, either a real object file +// or an incremental (unchanged) object. This is size and endian specific. + +template<int size, bool big_endian> +class Sized_relobj : public Relobj +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef Relobj::Symbols Symbols; + + static const Address invalid_address = static_cast<Address>(0) - 1; + + Sized_relobj(const std::string& name, Input_file* input_file) + : Relobj(name, input_file), local_got_offsets_(), section_offsets_() + { } + + Sized_relobj(const std::string& name, Input_file* input_file, + off_t offset) + : Relobj(name, input_file, offset), local_got_offsets_(), section_offsets_() + { } + + ~Sized_relobj() + { } + + // If this is a regular object, return a pointer to the Sized_relobj_file + // object. Otherwise, return NULL. + virtual Sized_relobj_file<size, big_endian>* + sized_relobj() + { return NULL; } + + const virtual Sized_relobj_file<size, big_endian>* + sized_relobj() const + { return NULL; } + + // Checks if the offset of input section SHNDX within its output + // section is invalid. + bool + is_output_section_offset_invalid(unsigned int shndx) const + { return this->get_output_section_offset(shndx) == invalid_address; } + + // Get the offset of input section SHNDX within its output section. + // This is -1 if the input section requires a special mapping, such + // as a merge section. The output section can be found in the + // output_sections_ field of the parent class Relobj. + Address + get_output_section_offset(unsigned int shndx) const + { + gold_assert(shndx < this->section_offsets_.size()); + return this->section_offsets_[shndx]; + } + + // Iterate over local symbols, calling a visitor class V for each GOT offset + // associated with a local symbol. + void + do_for_all_local_got_entries(Got_offset_list::Visitor* v) const; + + protected: + typedef Relobj::Output_sections Output_sections; + + // Clear the local symbol information. + void + clear_got_offsets() + { this->local_got_offsets_.clear(); } + + // Return the vector of section offsets. + std::vector<Address>& + section_offsets() + { return this->section_offsets_; } + + // Get the address of an output section. + uint64_t + do_output_section_address(unsigned int shndx); + + // Get the offset of a section. + uint64_t + do_output_section_offset(unsigned int shndx) const + { + Address off = this->get_output_section_offset(shndx); + if (off == invalid_address) + return -1ULL; + return off; + } + + // Set the offset of a section. + void + do_set_section_offset(unsigned int shndx, uint64_t off) + { + gold_assert(shndx < this->section_offsets_.size()); + this->section_offsets_[shndx] = + (off == static_cast<uint64_t>(-1) + ? invalid_address + : convert_types<Address, uint64_t>(off)); + } + + // Return whether the local symbol SYMNDX has a GOT offset of type + // GOT_TYPE. + bool + do_local_has_got_offset(unsigned int symndx, unsigned int got_type) const + { + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(symndx); + return (p != this->local_got_offsets_.end() + && p->second->get_offset(got_type) != -1U); + } + + // Return the GOT offset of type GOT_TYPE of the local symbol + // SYMNDX. + unsigned int + do_local_got_offset(unsigned int symndx, unsigned int got_type) const + { + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(symndx); + gold_assert(p != this->local_got_offsets_.end()); + unsigned int off = p->second->get_offset(got_type); + gold_assert(off != -1U); + return off; + } + + // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX + // to GOT_OFFSET. + void + do_set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset) + { + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(symndx); + if (p != this->local_got_offsets_.end()) + p->second->set_offset(got_type, got_offset); + else + { + Got_offset_list* g = new Got_offset_list(got_type, got_offset); + std::pair<Local_got_offsets::iterator, bool> ins = + this->local_got_offsets_.insert(std::make_pair(symndx, g)); + gold_assert(ins.second); + } + } + + // Return the word size of the object file. + virtual int + do_elfsize() const + { return size; } + + // Return TRUE if this is a big-endian object file. + virtual bool + do_is_big_endian() const + { return big_endian; } + + private: + // The GOT offsets of local symbols. This map also stores GOT offsets + // for tp-relative offsets for TLS symbols. + typedef Unordered_map<unsigned int, Got_offset_list*> Local_got_offsets; + + // GOT offsets for local non-TLS symbols, and tp-relative offsets + // for TLS symbols, indexed by symbol number. + Local_got_offsets local_got_offsets_; + // For each input section, the offset of the input section in its + // output section. This is INVALID_ADDRESS if the input section requires a + // special mapping. + std::vector<Address> section_offsets_; +}; + +// A regular object file. This is size and endian specific. + +template<int size, bool big_endian> +class Sized_relobj_file : public Sized_relobj<size, big_endian> +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef typename Sized_relobj<size, big_endian>::Symbols Symbols; + typedef std::vector<Symbol_value<size> > Local_values; + + static const Address invalid_address = static_cast<Address>(0) - 1; + + enum Compute_final_local_value_status + { + // No error. + CFLV_OK, + // An error occurred. + CFLV_ERROR, + // The local symbol has no output section. + CFLV_DISCARDED + }; + + Sized_relobj_file(const std::string& name, + Input_file* input_file, + off_t offset, + const typename elfcpp::Ehdr<size, big_endian>&); + + ~Sized_relobj_file(); + + // Set up the object file based on TARGET. + void + setup() + { this->do_setup(); } + + // Return a pointer to the Sized_relobj_file object. + Sized_relobj_file<size, big_endian>* + sized_relobj() + { return this; } + + const Sized_relobj_file<size, big_endian>* + sized_relobj() const + { return this; } + + // Return the ELF file type. + int + e_type() const + { return this->e_type_; } + + // Return the number of symbols. This is only valid after + // Object::add_symbols has been called. + unsigned int + symbol_count() const + { return this->local_symbol_count_ + this->symbols_.size(); } + + // If SYM is the index of a global symbol in the object file's + // symbol table, return the Symbol object. Otherwise, return NULL. + Symbol* + global_symbol(unsigned int sym) const + { + if (sym >= this->local_symbol_count_) + { + gold_assert(sym - this->local_symbol_count_ < this->symbols_.size()); + return this->symbols_[sym - this->local_symbol_count_]; + } + return NULL; + } + + // Return the section index of symbol SYM. Set *VALUE to its value + // in the object file. Set *IS_ORDINARY if this is an ordinary + // section index, not a special code between SHN_LORESERVE and + // SHN_HIRESERVE. Note that for a symbol which is not defined in + // this object file, this will set *VALUE to 0 and return SHN_UNDEF; + // it will not return the final value of the symbol in the link. + unsigned int + symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary); + + // Return a pointer to the Symbol_value structure which holds the + // value of a local symbol. + const Symbol_value<size>* + local_symbol(unsigned int sym) const + { + gold_assert(sym < this->local_values_.size()); + return &this->local_values_[sym]; + } + + // Return the index of local symbol SYM in the ordinary symbol + // table. A value of -1U means that the symbol is not being output. + unsigned int + symtab_index(unsigned int sym) const + { + gold_assert(sym < this->local_values_.size()); + return this->local_values_[sym].output_symtab_index(); + } + + // Return the index of local symbol SYM in the dynamic symbol + // table. A value of -1U means that the symbol is not being output. + unsigned int + dynsym_index(unsigned int sym) const + { + gold_assert(sym < this->local_values_.size()); + return this->local_values_[sym].output_dynsym_index(); + } + + // Return the input section index of local symbol SYM. + unsigned int + local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const + { + gold_assert(sym < this->local_values_.size()); + return this->local_values_[sym].input_shndx(is_ordinary); + } + + // Record that local symbol SYM must be in the output symbol table. + void + set_must_have_output_symtab_entry(unsigned int sym) + { + gold_assert(sym < this->local_values_.size()); + this->local_values_[sym].set_must_have_output_symtab_entry(); + } + + // Record that local symbol SYM needs a dynamic symbol entry. + void + set_needs_output_dynsym_entry(unsigned int sym) + { + gold_assert(sym < this->local_values_.size()); + this->local_values_[sym].set_needs_output_dynsym_entry(); + } + + // Return whether the local symbol SYMNDX has a PLT offset. + bool + local_has_plt_offset(unsigned int symndx) const; + + // Set the PLT offset of the local symbol SYMNDX. + void + set_local_plt_offset(unsigned int symndx, unsigned int plt_offset); + + // Adjust this local symbol value. Return false if the symbol + // should be discarded from the output file. + bool + adjust_local_symbol(Symbol_value<size>* lv) const + { return this->do_adjust_local_symbol(lv); } + + // Return the name of the symbol that spans the given offset in the + // specified section in this object. This is used only for error + // messages and is not particularly efficient. + bool + get_symbol_location_info(unsigned int shndx, off_t offset, + Symbol_location_info* info); + + // Look for a kept section corresponding to the given discarded section, + // and return its output address. This is used only for relocations in + // debugging sections. + Address + map_to_kept_section(unsigned int shndx, bool* found) const; + + // Compute final local symbol value. R_SYM is the local symbol index. + // LV_IN points to a local symbol value containing the input value. + // LV_OUT points to a local symbol value storing the final output value, + // which must not be a merged symbol value since before calling this + // method to avoid memory leak. SYMTAB points to a symbol table. + // + // The method returns a status code at return. If the return status is + // CFLV_OK, *LV_OUT contains the final value. If the return status is + // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED, + // *LV_OUT is not modified. + Compute_final_local_value_status + compute_final_local_value(unsigned int r_sym, + const Symbol_value<size>* lv_in, + Symbol_value<size>* lv_out, + const Symbol_table* symtab); + + protected: + typedef typename Sized_relobj<size, big_endian>::Output_sections + Output_sections; + + // Set up. + virtual void + do_setup(); + + // Read the symbols. + void + do_read_symbols(Read_symbols_data*); + + // Return the value of a local symbol. + uint64_t + do_local_symbol_value(unsigned int symndx, uint64_t addend) const + { + const Symbol_value<size>* symval = this->local_symbol(symndx); + return symval->value(this, addend); + } + + // Return the PLT offset for a local symbol. It is an error to call + // this if it doesn't have one. + unsigned int + do_local_plt_offset(unsigned int symndx) const; + + // Return whether local symbol SYMNDX is a TLS symbol. + bool + do_local_is_tls(unsigned int symndx) const + { return this->local_symbol(symndx)->is_tls_symbol(); } + + // Return the number of local symbols. + unsigned int + do_local_symbol_count() const + { return this->local_symbol_count_; } + + // Return the number of local symbols in the output symbol table. + unsigned int + do_output_local_symbol_count() const + { return this->output_local_symbol_count_; } + + // Return the number of local symbols in the output symbol table. + off_t + do_local_symbol_offset() const + { return this->local_symbol_offset_; } + + // Lay out the input sections. + void + do_layout(Symbol_table*, Layout*, Read_symbols_data*); + + // Layout sections whose layout was deferred while waiting for + // input files from a plugin. + void + do_layout_deferred_sections(Layout*); + + // Add the symbols to the symbol table. + void + do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*); + + Archive::Should_include + do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*, + std::string* why); + + // Iterate over global symbols, calling a visitor class V for each. + void + do_for_all_global_symbols(Read_symbols_data* sd, + Library_base::Symbol_visitor_base* v); + + // Read the relocs. + void + do_read_relocs(Read_relocs_data*); + + // Process the relocs to find list of referenced sections. Used only + // during garbage collection. + void + do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*); + + // Scan the relocs and adjust the symbol table. + void + do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*); + + // Count the local symbols. + void + do_count_local_symbols(Stringpool_template<char>*, + Stringpool_template<char>*); + + // Finalize the local symbols. + unsigned int + do_finalize_local_symbols(unsigned int, off_t, Symbol_table*); + + // Set the offset where local dynamic symbol information will be stored. + unsigned int + do_set_local_dynsym_indexes(unsigned int); + + // Set the offset where local dynamic symbol information will be stored. + unsigned int + do_set_local_dynsym_offset(off_t); + + // Relocate the input sections and write out the local symbols. + void + do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of); + + // Get the size of a section. + uint64_t + do_section_size(unsigned int shndx) + { return this->elf_file_.section_size(shndx); } + + // Get the name of a section. + std::string + do_section_name(unsigned int shndx) + { return this->elf_file_.section_name(shndx); } + + // Return the location of the contents of a section. + const unsigned char* + do_section_contents(unsigned int shndx, section_size_type* plen, + bool cache) + { + Object::Location loc(this->elf_file_.section_contents(shndx)); + *plen = convert_to_section_size_type(loc.data_size); + if (*plen == 0) + { + static const unsigned char empty[1] = { '\0' }; + return empty; + } + return this->get_view(loc.file_offset, *plen, true, cache); + } + + // Return section flags. + uint64_t + do_section_flags(unsigned int shndx); + + // Return section entsize. + uint64_t + do_section_entsize(unsigned int shndx); + + // Return section address. + uint64_t + do_section_address(unsigned int shndx) + { return this->elf_file_.section_addr(shndx); } + + // Return section type. + unsigned int + do_section_type(unsigned int shndx) + { return this->elf_file_.section_type(shndx); } + + // Return the section link field. + unsigned int + do_section_link(unsigned int shndx) + { return this->elf_file_.section_link(shndx); } + + // Return the section info field. + unsigned int + do_section_info(unsigned int shndx) + { return this->elf_file_.section_info(shndx); } + + // Return the section alignment. + uint64_t + do_section_addralign(unsigned int shndx) + { return this->elf_file_.section_addralign(shndx); } + + // Return the Xindex structure to use. + Xindex* + do_initialize_xindex(); + + // Get symbol counts. + void + do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const; + + // Get the global symbols. + const Symbols* + do_get_global_symbols() const + { return &this->symbols_; } + + // Adjust a section index if necessary. + unsigned int + adjust_shndx(unsigned int shndx) + { + if (shndx >= elfcpp::SHN_LORESERVE) + shndx += this->elf_file_.large_shndx_offset(); + return shndx; + } + + // Initialize input to output maps for section symbols in merged + // sections. + void + initialize_input_to_output_maps(); + + // Free the input to output maps for section symbols in merged + // sections. + void + free_input_to_output_maps(); + + // Return symbol table section index. + unsigned int + symtab_shndx() const + { return this->symtab_shndx_; } + + // Allow a child class to access the ELF file. + elfcpp::Elf_file<size, big_endian, Object>* + elf_file() + { return &this->elf_file_; } + + // Allow a child class to access the local values. + Local_values* + local_values() + { return &this->local_values_; } + + // Views and sizes when relocating. + struct View_size + { + unsigned char* view; + typename elfcpp::Elf_types<size>::Elf_Addr address; + off_t offset; + section_size_type view_size; + bool is_input_output_view; + bool is_postprocessing_view; + bool is_ctors_reverse_view; + }; + + typedef std::vector<View_size> Views; + + // Stash away info for a number of special sections. + // Return true if any of the sections found require local symbols to be read. + virtual bool + do_find_special_sections(Read_symbols_data* sd); + + // This may be overriden by a child class. + virtual void + do_relocate_sections(const Symbol_table* symtab, const Layout* layout, + const unsigned char* pshdrs, Output_file* of, + Views* pviews); + + // Adjust this local symbol value. Return false if the symbol + // should be discarded from the output file. + virtual bool + do_adjust_local_symbol(Symbol_value<size>*) const + { return true; } + + // Allow a child to set output local symbol count. + void + set_output_local_symbol_count(unsigned int value) + { this->output_local_symbol_count_ = value; } + + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + bool + do_section_is_compressed(unsigned int shndx, + section_size_type* uncompressed_size) const + { + if (this->compressed_sections_ == NULL) + return false; + Compressed_section_map::const_iterator p = + this->compressed_sections_->find(shndx); + if (p != this->compressed_sections_->end()) + { + if (uncompressed_size != NULL) + *uncompressed_size = p->second.size; + return true; + } + return false; + } + + // Return a view of the uncompressed contents of a section. Set *PLEN + // to the size. Set *IS_NEW to true if the contents need to be deleted + // by the caller. + const unsigned char* + do_decompressed_section_contents(unsigned int shndx, + section_size_type* plen, + bool* is_new); + + // Discard any buffers of decompressed sections. This is done + // at the end of the Add_symbols task. + void + do_discard_decompressed_sections(); + + private: + // For convenience. + typedef Sized_relobj_file<size, big_endian> This; + static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size; + static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; + static const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + typedef elfcpp::Shdr<size, big_endian> Shdr; + + // To keep track of discarded comdat sections, we need to map a member + // section index to the object and section index of the corresponding + // kept section. + struct Kept_comdat_section + { + Kept_comdat_section(Relobj* a_object, unsigned int a_shndx) + : object(a_object), shndx(a_shndx) + { } + Relobj* object; + unsigned int shndx; + }; + typedef std::map<unsigned int, Kept_comdat_section> + Kept_comdat_section_table; + + // Find the SHT_SYMTAB section, given the section headers. + void + find_symtab(const unsigned char* pshdrs); + + // Return whether SHDR has the right flags for a GNU style exception + // frame section. + bool + check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const; + + // Return whether there is a section named .eh_frame which might be + // a GNU style exception frame section. + bool + find_eh_frame(const unsigned char* pshdrs, const char* names, + section_size_type names_size) const; + + // Whether to include a section group in the link. + bool + include_section_group(Symbol_table*, Layout*, unsigned int, const char*, + const unsigned char*, const char*, section_size_type, + std::vector<bool>*); + + // Whether to include a linkonce section in the link. + bool + include_linkonce_section(Layout*, unsigned int, const char*, + const elfcpp::Shdr<size, big_endian>&); + + // Layout an input section. + void + layout_section(Layout* layout, unsigned int shndx, const char* name, + const typename This::Shdr& shdr, unsigned int reloc_shndx, + unsigned int reloc_type); + + // Layout an input .eh_frame section. + void + layout_eh_frame_section(Layout* layout, const unsigned char* symbols_data, + section_size_type symbols_size, + const unsigned char* symbol_names_data, + section_size_type symbol_names_size, + unsigned int shndx, const typename This::Shdr&, + unsigned int reloc_shndx, unsigned int reloc_type); + + // Write section data to the output file. Record the views and + // sizes in VIEWS for use when relocating. + void + write_sections(const Layout*, const unsigned char* pshdrs, Output_file*, + Views*); + + // Relocate the sections in the output file. + void + relocate_sections(const Symbol_table* symtab, const Layout* layout, + const unsigned char* pshdrs, Output_file* of, + Views* pviews) + { this->do_relocate_sections(symtab, layout, pshdrs, of, pviews); } + + // Reverse the words in a section. Used for .ctors sections mapped + // to .init_array sections. + void + reverse_words(unsigned char*, section_size_type); + + // Scan the input relocations for --emit-relocs. + void + emit_relocs_scan(Symbol_table*, Layout*, const unsigned char* plocal_syms, + const Read_relocs_data::Relocs_list::iterator&); + + // Scan the input relocations for --emit-relocs, templatized on the + // type of the relocation section. + template<int sh_type> + void + emit_relocs_scan_reltype(Symbol_table*, Layout*, + const unsigned char* plocal_syms, + const Read_relocs_data::Relocs_list::iterator&, + Relocatable_relocs*); + + // Scan the input relocations for --incremental. + void + incremental_relocs_scan(const Read_relocs_data::Relocs_list::iterator&); + + // Scan the input relocations for --incremental, templatized on the + // type of the relocation section. + template<int sh_type> + void + incremental_relocs_scan_reltype( + const Read_relocs_data::Relocs_list::iterator&); + + void + incremental_relocs_write(const Relocate_info<size, big_endian>*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section*, + Address output_offset, + Output_file*); + + template<int sh_type> + void + incremental_relocs_write_reltype(const Relocate_info<size, big_endian>*, + const unsigned char* prelocs, + size_t reloc_count, + Output_section*, + Address output_offset, + Output_file*); + + // A type shared by split_stack_adjust_reltype and find_functions. + typedef std::map<section_offset_type, section_size_type> Function_offsets; + + // Check for -fsplit-stack routines calling non-split-stack routines. + void + split_stack_adjust(const Symbol_table*, const unsigned char* pshdrs, + unsigned int sh_type, unsigned int shndx, + const unsigned char* prelocs, size_t reloc_count, + unsigned char* view, section_size_type view_size, + Reloc_symbol_changes** reloc_map); + + template<int sh_type> + void + split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs, + unsigned int shndx, const unsigned char* prelocs, + size_t reloc_count, unsigned char* view, + section_size_type view_size, + Reloc_symbol_changes** reloc_map); + + // Find all functions in a section. + void + find_functions(const unsigned char* pshdrs, unsigned int shndx, + Function_offsets*); + + // Write out the local symbols. + void + write_local_symbols(Output_file*, + const Stringpool_template<char>*, + const Stringpool_template<char>*, + Output_symtab_xindex*, + Output_symtab_xindex*, + off_t); + + // Record a mapping from discarded section SHNDX to the corresponding + // kept section. + void + set_kept_comdat_section(unsigned int shndx, Relobj* kept_object, + unsigned int kept_shndx) + { + Kept_comdat_section kept(kept_object, kept_shndx); + this->kept_comdat_sections_.insert(std::make_pair(shndx, kept)); + } + + // Find the kept section corresponding to the discarded section + // SHNDX. Return true if found. + bool + get_kept_comdat_section(unsigned int shndx, Relobj** kept_object, + unsigned int* kept_shndx) const + { + typename Kept_comdat_section_table::const_iterator p = + this->kept_comdat_sections_.find(shndx); + if (p == this->kept_comdat_sections_.end()) + return false; + *kept_object = p->second.object; + *kept_shndx = p->second.shndx; + return true; + } + + // Compute final local symbol value. R_SYM is the local symbol index. + // LV_IN points to a local symbol value containing the input value. + // LV_OUT points to a local symbol value storing the final output value, + // which must not be a merged symbol value since before calling this + // method to avoid memory leak. RELOCATABLE indicates whether we are + // linking a relocatable output. OUT_SECTIONS is an array of output + // sections. OUT_OFFSETS is an array of offsets of the sections. SYMTAB + // points to a symbol table. + // + // The method returns a status code at return. If the return status is + // CFLV_OK, *LV_OUT contains the final value. If the return status is + // CFLV_ERROR, *LV_OUT is 0. If the return status is CFLV_DISCARDED, + // *LV_OUT is not modified. + inline Compute_final_local_value_status + compute_final_local_value_internal(unsigned int r_sym, + const Symbol_value<size>* lv_in, + Symbol_value<size>* lv_out, + bool relocatable, + const Output_sections& out_sections, + const std::vector<Address>& out_offsets, + const Symbol_table* symtab); + + // The PLT offsets of local symbols. + typedef Unordered_map<unsigned int, unsigned int> Local_plt_offsets; + + // Saved information for sections whose layout was deferred. + struct Deferred_layout + { + static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; + Deferred_layout(unsigned int shndx, const char* name, + const unsigned char* pshdr, + unsigned int reloc_shndx, unsigned int reloc_type) + : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx), + reloc_type_(reloc_type) + { + memcpy(this->shdr_data_, pshdr, shdr_size); + } + unsigned int shndx_; + std::string name_; + unsigned int reloc_shndx_; + unsigned int reloc_type_; + unsigned char shdr_data_[shdr_size]; + }; + + // General access to the ELF file. + elfcpp::Elf_file<size, big_endian, Object> elf_file_; + // Type of ELF file (ET_REL or ET_EXEC). ET_EXEC files are allowed + // as input files only for the --just-symbols option. + int e_type_; + // Index of SHT_SYMTAB section. + unsigned int symtab_shndx_; + // The number of local symbols. + unsigned int local_symbol_count_; + // The number of local symbols which go into the output file. + unsigned int output_local_symbol_count_; + // The number of local symbols which go into the output file's dynamic + // symbol table. + unsigned int output_local_dynsym_count_; + // The entries in the symbol table for the external symbols. + Symbols symbols_; + // Number of symbols defined in object file itself. + size_t defined_count_; + // File offset for local symbols (relative to start of symbol table). + off_t local_symbol_offset_; + // File offset for local dynamic symbols (absolute). + off_t local_dynsym_offset_; + // Values of local symbols. + Local_values local_values_; + // PLT offsets for local symbols. + Local_plt_offsets local_plt_offsets_; + // Table mapping discarded comdat sections to corresponding kept sections. + Kept_comdat_section_table kept_comdat_sections_; + // Whether this object has a GNU style .eh_frame section. + bool has_eh_frame_; + // If this object has a GNU style .eh_frame section that is discarded in + // output, record the index here. Otherwise it is -1U. + unsigned int discarded_eh_frame_shndx_; + // The list of sections whose layout was deferred. + std::vector<Deferred_layout> deferred_layout_; + // The list of relocation sections whose layout was deferred. + std::vector<Deferred_layout> deferred_layout_relocs_; + // For compressed debug sections, map section index to uncompressed size + // and contents. + Compressed_section_map* compressed_sections_; +}; + +// A class to manage the list of all objects. + +class Input_objects +{ + public: + Input_objects() + : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL) + { } + + // The type of the list of input relocateable objects. + typedef std::vector<Relobj*> Relobj_list; + typedef Relobj_list::const_iterator Relobj_iterator; + + // The type of the list of input dynamic objects. + typedef std::vector<Dynobj*> Dynobj_list; + typedef Dynobj_list::const_iterator Dynobj_iterator; + + // Add an object to the list. Return true if all is well, or false + // if this object should be ignored. + bool + add_object(Object*); + + // Start processing an archive. + void + archive_start(Archive*); + + // Stop processing an archive. + void + archive_stop(Archive*); + + // For each dynamic object, check whether we've seen all of its + // explicit dependencies. + void + check_dynamic_dependencies() const; + + // Return whether an object was found in the system library + // directory. + bool + found_in_system_library_directory(const Object*) const; + + // Print symbol counts. + void + print_symbol_counts(const Symbol_table*) const; + + // Print a cross reference table. + void + print_cref(const Symbol_table*, FILE*) const; + + // Iterate over all regular objects. + + Relobj_iterator + relobj_begin() const + { return this->relobj_list_.begin(); } + + Relobj_iterator + relobj_end() const + { return this->relobj_list_.end(); } + + // Iterate over all dynamic objects. + + Dynobj_iterator + dynobj_begin() const + { return this->dynobj_list_.begin(); } + + Dynobj_iterator + dynobj_end() const + { return this->dynobj_list_.end(); } + + // Return whether we have seen any dynamic objects. + bool + any_dynamic() const + { return !this->dynobj_list_.empty(); } + + // Return the number of non dynamic objects. + int + number_of_relobjs() const + { return this->relobj_list_.size(); } + + // Return the number of input objects. + int + number_of_input_objects() const + { return this->relobj_list_.size() + this->dynobj_list_.size(); } + + private: + Input_objects(const Input_objects&); + Input_objects& operator=(const Input_objects&); + + // The list of ordinary objects included in the link. + Relobj_list relobj_list_; + // The list of dynamic objects included in the link. + Dynobj_list dynobj_list_; + // SONAMEs that we have seen. + Unordered_set<std::string> sonames_; + // Manage cross-references if requested. + Cref* cref_; +}; + +// Some of the information we pass to the relocation routines. We +// group this together to avoid passing a dozen different arguments. + +template<int size, bool big_endian> +struct Relocate_info +{ + // Symbol table. + const Symbol_table* symtab; + // Layout. + const Layout* layout; + // Object being relocated. + Sized_relobj_file<size, big_endian>* object; + // Section index of relocation section. + unsigned int reloc_shndx; + // Section header of relocation section. + const unsigned char* reloc_shdr; + // Section index of section being relocated. + unsigned int data_shndx; + // Section header of data section. + const unsigned char* data_shdr; + + // Return a string showing the location of a relocation. This is + // only used for error messages. + std::string + location(size_t relnum, off_t reloffset) const; +}; + +// This is used to represent a section in an object and is used as the +// key type for various section maps. +typedef std::pair<Object*, unsigned int> Section_id; + +// This is similar to Section_id but is used when the section +// pointers are const. +typedef std::pair<const Object*, unsigned int> Const_section_id; + +// The hash value is based on the address of an object in memory during +// linking. It is okay to use this for looking up sections but never use +// this in an unordered container that we want to traverse in a repeatable +// manner. + +struct Section_id_hash +{ + size_t operator()(const Section_id& loc) const + { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; } +}; + +struct Const_section_id_hash +{ + size_t operator()(const Const_section_id& loc) const + { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; } +}; + +// Return whether INPUT_FILE contains an ELF object start at file +// offset OFFSET. This sets *START to point to a view of the start of +// the file. It sets *READ_SIZE to the number of bytes in the view. + +extern bool +is_elf_object(Input_file* input_file, off_t offset, + const unsigned char** start, int* read_size); + +// Return an Object appropriate for the input file. P is BYTES long, +// and holds the ELF header. If PUNCONFIGURED is not NULL, then if +// this sees an object the linker is not configured to support, it +// sets *PUNCONFIGURED to true and returns NULL without giving an +// error message. + +extern Object* +make_elf_object(const std::string& name, Input_file*, + off_t offset, const unsigned char* p, + section_offset_type bytes, bool* punconfigured); + +} // end namespace gold + +#endif // !defined(GOLD_OBJECT_H) |