X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fobject.h;h=95f6d56e0861b4b1a49c3a8844adb9b87c3e3c09;hb=4d625b70fc3fb7facc7159feb8d49b78ac6641f9;hp=dbe0ca1390ebaf4056ae2008736765cd5595fd29;hpb=6a74a71947df73c828f073af0dcad0c323dcd8c4;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/object.h b/gold/object.h index dbe0ca1390..95f6d56e08 100644 --- a/gold/object.h +++ b/gold/object.h @@ -1,6 +1,6 @@ // object.h -- support for an object file for linking in gold -*- C++ -*- -// Copyright 2006, 2007 Free Software Foundation, Inc. +// Copyright (C) 2006-2016 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -30,18 +30,25 @@ #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_section_data; class Output_file; +class Output_symtab_xindex; +class Pluginobj; class Dynobj; class Object_merge_map; class Relocatable_relocs; +struct Symbols_data; template class Stringpool_template; @@ -50,6 +57,13 @@ class Stringpool_template; 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. @@ -89,7 +103,7 @@ struct Symbol_location_info { std::string source_file; std::string enclosing_symbol_name; - int line_number; + elfcpp::STT enclosing_symbol_type; }; // Data about a single relocation section. This is read in @@ -97,6 +111,13 @@ struct Symbol_location_info 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. @@ -111,6 +132,8 @@ struct Section_relocs 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 @@ -118,6 +141,13 @@ struct Section_relocs struct Read_relocs_data { + Read_relocs_data() + : local_symbols(NULL) + { } + + ~Read_relocs_data() + { delete this->local_symbols; } + typedef std::vector Relocs_list; // The relocations. Relocs_list relocs; @@ -125,6 +155,233 @@ struct Read_relocs_data 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 + 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 + 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 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_; +}; + +// The Local_got_entry_key used to index the GOT offsets for local +// non-TLS symbols, and tp-relative offsets for TLS symbols. + +class Local_got_entry_key +{ + public: + Local_got_entry_key(unsigned int symndx, uint64_t addend) + : symndx_(symndx), addend_(addend) + {} + + // Whether this equals to another Local_got_entry_key. + bool + eq(const Local_got_entry_key& key) const + { + return (this->symndx_ == key.symndx_ && this->addend_ == key.addend_); + } + + // 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(this->symndx_)) * prime; + h = (h ^ static_cast(this->addend_)) * prime; + return h; + } + + // Functors for associative containers. + struct equal_to + { + bool + operator()(const Local_got_entry_key& key1, + const Local_got_entry_key& key2) const + { return key1.eq(key2); } + }; + + struct hash + { + size_t + operator()(const Local_got_entry_key& key) const + { return key.hash_value(); } + }; + + private: + // The local symbol index. + unsigned int symndx_; + // The addend. + uint64_t addend_; +}; + +// Type for mapping section index to uncompressed size and contents. + +struct Compressed_section_info +{ + section_size_type size; + elfcpp::Elf_Xword flag; + const unsigned char* contents; +}; +typedef std::map Compressed_section_map; + +template +Compressed_section_map* +build_compressed_section_map(const unsigned char* pshdrs, unsigned int shnum, + const char* names, section_size_type names_size, + Object* obj, bool decompress_if_needed); + // 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). @@ -132,6 +389,8 @@ struct Read_relocs_data class Object { public: + typedef std::vector 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 @@ -139,13 +398,26 @@ class Object 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), target_(NULL) - { input_file->file().add_object(); } + 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), + compressed_sections_(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() - { this->input_file_->file().remove_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 tuser. + // Return the name of the object as we would report it to the user. const std::string& name() const { return this->name_; } @@ -160,42 +432,115 @@ class Object is_dynamic() const { return this->is_dynamic_; } - // Return the target structure associated with this object. - Target* - target() const - { return this->target_; } + // Return the word size of the object file. + virtual int elfsize() const = 0; + + // Return TRUE if this is a big-endian object file. + virtual bool is_big_endian() const = 0; + + // 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) - { this->input_file()->file().lock(t); } + { + if (this->input_file_ != NULL) + this->input_file_->file().lock(t); + } // Unlock the underlying file. void unlock(const Task* t) - { this->input_file()->file().unlock(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()->file().is_locked(); } + { return this->input_file_ != NULL && this->input_file_->file().is_locked(); } // Return the token, so that the task can be queued. Task_token* token() - { return this->input_file()->file().token(); } + { + if (this->input_file_ == NULL) + return NULL; + return this->input_file()->file().token(); + } // Release the underlying file. void release() - { this->input_file_->file().release(); } + { + if (this->input_file_ != NULL) + this->input_file()->file().release(); + } - // Return the sized target structure associated with this object. - // This is like the target method but it returns a pointer of - // appropriate checked type. - template - Sized_target* - sized_target(ACCEPT_SIZE_ENDIAN_ONLY) const; + // 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 @@ -207,6 +552,29 @@ class Object 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) @@ -214,7 +582,7 @@ class Object // Return the name of a section given a section index. std::string - section_name(unsigned int shndx) + section_name(unsigned int shndx) const { return this->do_section_name(shndx); } // Return the section flags given a section index. @@ -222,6 +590,16 @@ class Object 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) @@ -242,6 +620,25 @@ class Object 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) @@ -255,8 +652,26 @@ class Object // Add symbol information to the global symbol table. void - add_symbols(Symbol_table* symtab, Read_symbols_data* sd) - { this->do_add_symbols(symtab, sd); } + 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 @@ -283,7 +698,7 @@ class Object // Return a View. View view(off_t file_offset, section_size_type data_size) - { return View(this->get_view(file_offset, data_size, true)); } + { return View(this->get_view(file_offset, data_size, true, true)); } // Report an error. void @@ -302,27 +717,28 @@ class Object // Get a View given a Location. View view(Location loc) - { return View(this->get_view(loc.file_offset, loc.data_size, true)); } + { 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 cache) + get_view(off_t start, section_size_type size, bool aligned, bool cache) { - return this->input_file()->file().get_view(start + this->offset_, size, - 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 cache) + get_lasting_view(off_t start, section_size_type size, bool aligned, + bool cache) { - return this->input_file()->file().get_lasting_view(start + this->offset_, - size, 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) const + 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. @@ -333,9 +749,133 @@ class Object // Stop caching views in the underlying file. void clear_view_cache_marks() - { this->input_file()->file().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; } + + // Clear flag that this object was linked with --as-needed. + void + clear_as_needed() + { this->as_needed_ = false; } + + // 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; } + + bool + 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 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); + + // Discard any buffers of decompressed sections. This is done + // at the end of the Add_symbols task. + void + 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); } + + // Return the output view for section SHNDX. + unsigned char* + get_output_view(unsigned int shndx, section_size_type* plen) const + { return this->do_get_output_view(shndx, plen); } 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; @@ -347,12 +887,27 @@ class Object // Add symbol information to the global symbol table--implemented by // child class. virtual void - do_add_symbols(Symbol_table*, Read_symbols_data*) = 0; + do_add_symbols(Symbol_table*, Read_symbols_data*, 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 Location - do_section_contents(unsigned int shndx) = 0; + 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 @@ -360,12 +915,20 @@ class Object // Get the name of a section--implemented by child class. virtual std::string - do_section_name(unsigned int shndx) = 0; + do_section_name(unsigned int shndx) const = 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; @@ -382,26 +945,39 @@ class Object virtual uint64_t do_section_addralign(unsigned int shndx) = 0; - // Get the file. We pass on const-ness. - Input_file* - input_file() - { return this->input_file_; } + // Return the output section given a section index--implemented + // by child class. + virtual Output_section* + do_output_section(unsigned int) const + { gold_unreachable(); } - const Input_file* - input_file() const - { return this->input_file_; } + // Get the address of a section--implemented by child class. + virtual uint64_t + do_output_section_address(unsigned int) + { gold_unreachable(); } - // Set the target. - void - set_target(int machine, int size, bool big_endian, int osabi, - int abiversion); + // 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 and Sized_dynobj. + // Functions used by both Sized_relobj_file and Sized_dynobj. // Read the section data into a Read_symbols_data object. template @@ -409,6 +985,24 @@ class Object read_section_data(elfcpp::Elf_file*, 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 + 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. @@ -416,6 +1010,43 @@ class Object 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); + + // 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(); } + + // Return the output view for a section. + virtual unsigned char* + do_get_output_view(unsigned int, section_size_type*) const + { gold_unreachable(); } + + void + set_compressed_sections(Compressed_section_map* compressed_sections) + { this->compressed_sections_ = compressed_sections; } + + Compressed_section_map* + compressed_sections() + { return this->compressed_sections_; } + private: // This class may not be copied. Object(const Object&); @@ -431,53 +1062,174 @@ class Object // Number of input sections. unsigned int shnum_; // Whether this is a dynamic object. - bool is_dynamic_; - // Target functions--may be NULL if the target is not known. - Target* target_; + 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_; + // For compressed debug sections, map section index to uncompressed size + // and contents. + Compressed_section_map* compressed_sections_; }; -// Implement sized_target inline for efficiency. This approach breaks -// static type checking, but is made safe using asserts. - -template -inline Sized_target* -Object::sized_target(ACCEPT_SIZE_ENDIAN_ONLY) const -{ - gold_assert(this->target_->get_size() == size); - gold_assert(this->target_->is_big_endian() ? big_endian : !big_endian); - return static_cast*>(this->target_); -} - // A regular object (ET_REL). This is an abstract base class itself. -// The implementation is the template class Sized_relobj. +// 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), - map_to_output_(), + output_sections_(), map_to_relocatable_relocs_(NULL), object_merge_map_(NULL), - relocs_must_follow_section_writes_(false) + relocs_must_follow_section_writes_(false), + sd_(NULL), + reloc_counts_(NULL), + reloc_bases_(NULL), + first_dyn_reloc_(0), + dyn_reloc_count_(0) { } - // Read the relocs. + // 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(const General_options& options, Symbol_table* symtab, - Layout* layout, Read_relocs_data* rd) - { return this->do_scan_relocs(options, symtab, layout, rd); } + 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, 0); } + + // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset + // of type GOT_TYPE. + bool + local_has_got_offset(unsigned int symndx, unsigned int got_type, + uint64_t addend) const + { return this->do_local_has_got_offset(symndx, got_type, addend); } + + // 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, 0); } + + // Return the GOT offset of type GOT_TYPE of the local symbol + // SYMNDX plus ADDEND. 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, + uint64_t addend) const + { return this->do_local_got_offset(symndx, got_type, addend); } + + // 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, 0); } + + // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX + // plus ADDEND to GOT_OFFSET. + void + set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset, uint64_t addend) + { this->do_set_local_got_offset(symndx, got_type, got_offset, addend); } + + // 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. @@ -490,8 +1242,8 @@ class Relobj : public Object // indexes for the local variables, and set the offset where local // symbol information will be stored. Returns the new local symbol index. unsigned int - finalize_local_symbols(unsigned int index, off_t off) - { return this->do_finalize_local_symbols(index, off); } + 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 @@ -503,45 +1255,52 @@ class Relobj : public Object 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 General_options& options, const Symbol_table* symtab, - const Layout* layout, Output_file* of) - { return this->do_relocate(options, symtab, layout, of); } + 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->map_to_output_.size()); - return this->map_to_output_[shndx].output_section != NULL; + gold_assert(shndx < this->output_sections_.size()); + return this->output_sections_[shndx] != NULL; } - // Return whether an input section requires special - // handling--whether it is not simply mapped from the input file to - // the output file. - bool - is_section_specially_mapped(unsigned int shndx) const + // 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->map_to_output_.size()); - return (this->map_to_output_[shndx].output_section != NULL - && this->map_to_output_[shndx].offset == -1); + gold_assert(shndx < this->output_sections_.size()); + this->output_sections_[shndx] = os; } - - // Given a section index, return the corresponding Output_section - // (which will be NULL if the section is not included in the link) - // and set *POFF to the offset within that section. *POFF will be - // set to -1 if the section requires special handling. - inline Output_section* - output_section(unsigned int shndx, section_offset_type* poff) const; - + // Set the offset of an input section within its output section. void - set_section_offset(unsigned int shndx, section_offset_type off) - { - gold_assert(shndx < this->map_to_output_.size()); - this->map_to_output_[shndx].offset = off; - } + 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 @@ -551,18 +1310,28 @@ class Relobj : public Object 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_; } + get_or_create_merge_map(); - // Set the object merge map. + template void - set_merge_map(Object_merge_map* object_merge_map) - { - gold_assert(this->object_merge_map_ == NULL); - this->object_merge_map_ = object_merge_map; - } + initialize_input_to_output_map(unsigned int shndx, + typename elfcpp::Elf_types::Elf_Addr starting_address, + Unordered_map::Elf_Addr>* output_address) const; + + void + add_merge_mapping(Output_section_data *output_data, + unsigned int shndx, section_offset_type offset, + section_size_type length, + section_offset_type output_offset); + + bool + merge_output_offset(unsigned int shndx, section_offset_type offset, + section_offset_type *poutput) const; + + const Output_section_data* + find_merge_section(unsigned int shndx) const; // Record the relocatable reloc info for an input reloc section. void @@ -580,33 +1349,90 @@ class Relobj : public Object 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: - // What we need to know to map an input section to an output - // section. We keep an array of these, one for each input section, - // indexed by the input section number. - struct Map_to_output - { - // The output section. This is NULL if the input section is to be - // discarded. - Output_section* output_section; - // The offset within the output section. This is -1 if the - // section requires special handling. - section_offset_type offset; - }; + // 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_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(const General_options&, Symbol_table*, Layout*, - Read_relocs_data*) = 0; + 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 plus addend has a GOT offset + // of a given type. + virtual bool + do_local_has_got_offset(unsigned int symndx, + unsigned int got_type, uint64_t addend) const = 0; + + // Return the GOT offset of a given type of a local symbol plus addend. + virtual unsigned int + do_local_got_offset(unsigned int symndx, unsigned int got_type, + uint64_t addend) const = 0; + + // Set the GOT offset with a given type for a local symbol plus addend. + virtual void + do_set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset, uint64_t addend) = 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*, @@ -616,7 +1442,7 @@ class Relobj : public Object // for the local variables, and set the offset where local symbol // information will be stored. virtual unsigned int - do_finalize_local_symbols(unsigned int, off_t) = 0; + 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 @@ -629,17 +1455,35 @@ class Relobj : public Object // Relocate the input sections and write out the local // symbols--implemented by child class. virtual void - do_relocate(const General_options& options, const Symbol_table* symtab, - const Layout*, Output_file* of) = 0; + 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. - std::vector& - map_to_output() - { return this->map_to_output_; } + Output_sections& + output_sections() + { return this->output_sections_; } - const std::vector& - map_to_output() const - { return this->map_to_output_; } + const Output_sections& + output_sections() const + { return this->output_sections_; } // Set the size of the relocatable relocs array. void @@ -655,9 +1499,59 @@ class Relobj : public Object 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. - std::vector map_to_output_; + 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* map_to_relocatable_relocs_; @@ -667,18 +1561,23 @@ class Relobj : public Object // 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_; }; -// Implement Object::output_section inline for efficiency. -inline Output_section* -Relobj::output_section(unsigned int shndx, section_offset_type* poff) const -{ - gold_assert(shndx < this->map_to_output_.size()); - const Map_to_output& mo(this->map_to_output_[shndx]); - *poff = mo.offset; - return mo.output_section; -} - // This 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. @@ -718,13 +1617,36 @@ class Merged_symbol_value Value value(const Relobj* object, unsigned int input_shndx, Value addend) const { - Value input_offset = this->input_value_ + addend; + // 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; + return p->second + addend; - return this->value_from_output_section(object, input_shndx, input_offset); + return (this->value_from_output_section(object, input_shndx, input_offset) + + addend); } private: @@ -757,21 +1679,30 @@ class Symbol_value Symbol_value() : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0), - is_section_symbol_(false), is_tls_symbol_(false), - has_output_value_(true) + 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 Value - value(const Sized_relobj* object, Value addend) const + value(const Sized_relobj_file* object, Value addend) const { if (this->has_output_value_) return this->u_.value + addend; else - return this->u_.merged_symbol_value->value(object, this->input_shndx_, - addend); + { + 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. @@ -797,7 +1728,7 @@ class Symbol_value { if (!this->has_output_value_) { - gold_assert(this->is_section_symbol_); + gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_); Merged_symbol_value* msv = this->u_.merged_symbol_value; msv->initialize_input_to_output_map(object, this->input_shndx_); } @@ -820,22 +1751,44 @@ class Symbol_value { this->u_.value = value; } // Return the input value. This is only called by - // finalize_local_symbols. + // finalize_local_symbols and (in special cases) relocate_section. Value input_value() const { return this->u_.value; } - // Return whether this symbol should go into the output symbol + // 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 - needs_output_symtab_entry() const - { return this->output_symtab_index_ != -1U; } + 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->output_symtab_index_ != 0); + gold_assert(this->is_output_symtab_index_set() + && this->output_symtab_index_ != -1U); return this->output_symtab_index_; } @@ -843,7 +1796,8 @@ class Symbol_value void set_output_symtab_index(unsigned int i) { - gold_assert(this->output_symtab_index_ == 0); + gold_assert(!this->is_output_symtab_index_set()); + gold_assert(i != 0 && i != -1U && i != -2U); this->output_symtab_index_ = i; } @@ -856,14 +1810,24 @@ class Symbol_value 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 output symbol + // Return whether this symbol should go into the dynamic symbol // table. bool needs_output_dynsym_entry() const @@ -871,108 +1835,376 @@ class Symbol_value 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. + // 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* 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 vec_; +}; + +// 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 +class Sized_relobj : public Relobj +{ + public: + typedef typename elfcpp::Elf_types::Elf_Addr Address; + typedef Relobj::Symbols Symbols; + + static const Address invalid_address = static_cast
(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* + sized_relobj() + { return NULL; } + + const virtual Sized_relobj_file* + 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
& + 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(-1) + ? invalid_address + : convert_types(off)); + } + + // Return whether the local symbol SYMNDX plus ADDEND has a GOT offset + // of type GOT_TYPE. + bool + do_local_has_got_offset(unsigned int symndx, unsigned int got_type, + uint64_t addend) const + { + Local_got_entry_key key(symndx, addend); + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(key); + 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 plus ADDEND. unsigned int - output_dynsym_index() const + do_local_got_offset(unsigned int symndx, unsigned int got_type, + uint64_t addend) const { - gold_assert(this->output_dynsym_index_ != 0); - return this->output_dynsym_index_; + Local_got_entry_key key(symndx, addend); + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(key); + 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 index of the input section in the input file. + // Set the GOT offset with type GOT_TYPE of the local symbol SYMNDX + // plus ADDEND to GOT_OFFSET. void - set_input_shndx(unsigned int i) + do_set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset, uint64_t addend) { - this->input_shndx_ = i; - // input_shndx_ field is a bitfield, so make sure that the value - // fits. - gold_assert(this->input_shndx_ == i); + Local_got_entry_key key(symndx, addend); + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(key); + 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 ins = + this->local_got_offsets_.insert(std::make_pair(key, g)); + gold_assert(ins.second); + } } - // Return the index of the input section in the input file. - unsigned int - input_shndx() const - { 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() - { this->is_section_symbol_ = true; } - - // Record that this is a TLS symbol. - void - set_is_tls_symbol() - { this->is_tls_symbol_ = true; } + // Return the word size of the object file. + virtual int + do_elfsize() const + { return size; } - // Return TRUE if this is a TLS symbol. - bool - is_tls_symbol() const - { return this->is_tls_symbol_; } + // Return TRUE if this is a big-endian object file. + virtual bool + do_is_big_endian() const + { return big_endian; } private: - // The index of this local symbol in the output symbol table. This - // will be -1 if the symbol should not go into the symbol table. - unsigned int output_symtab_index_; - // The index of this local symbol in the dynamic symbol table. This - // will be -1 if the symbol should not go into the symbol table. - unsigned int output_dynsym_index_; - // The section index in the input file in which this symbol is - // defined. - unsigned int input_shndx_ : 29; - // Whether this is a STT_SECTION symbol. - bool is_section_symbol_ : 1; - // Whether this is a STT_TLS symbol. - bool is_tls_symbol_ : 1; - // Whether 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* merged_symbol_value; - } u_; + // The GOT offsets of local symbols. This map also stores GOT offsets + // for tp-relative offsets for TLS symbols. + typedef Unordered_map Local_got_offsets; + + // GOT offsets for local non-TLS symbols, and tp-relative offsets + // for TLS symbols, indexed by local got entry key class. + 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
section_offsets_; }; // A regular object file. This is size and endian specific. template -class Sized_relobj : public Relobj +class Sized_relobj_file : public Sized_relobj { public: typedef typename elfcpp::Elf_types::Elf_Addr Address; - typedef std::vector Symbols; + typedef typename Sized_relobj::Symbols Symbols; typedef std::vector > Local_values; - Sized_relobj(const std::string& name, Input_file* input_file, off_t offset, - const typename elfcpp::Ehdr&); + static const Address invalid_address = static_cast
(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&); - ~Sized_relobj(); + ~Sized_relobj_file(); - // Set up the object file based on the ELF header. + // Set up the object file based on TARGET. void - setup(const typename elfcpp::Ehdr&); + setup() + { this->do_setup(); } + + // Return a pointer to the Sized_relobj_file object. + Sized_relobj_file* + sized_relobj() + { return this; } + + const Sized_relobj_file* + 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. @@ -988,12 +2220,13 @@ class Sized_relobj : public Relobj } // Return the section index of symbol SYM. Set *VALUE to its value - // in the object file. Note that for a symbol which is not defined - // in this object file, this will set *VALUE to 0 and return - // SHN_UNDEF; it will not return the final value of the symbol in - // the link. + // 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); + 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. @@ -1024,25 +2257,21 @@ class Sized_relobj : public Relobj // Return the input section index of local symbol SYM. unsigned int - local_symbol_input_shndx(unsigned int sym) const + 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(); + return this->local_values_[sym].input_shndx(is_ordinary); } - // Return the appropriate Sized_target structure. - Sized_target* - sized_target() + // Record that local symbol SYM must be in the output symbol table. + void + set_must_have_output_symtab_entry(unsigned int sym) { - return this->Object::sized_target - SELECT_SIZE_ENDIAN_NAME(size, big_endian) ( - SELECT_SIZE_ENDIAN_ONLY(size, big_endian)); + gold_assert(sym < this->local_values_.size()); + this->local_values_[sym].set_must_have_output_symtab_entry(); } - // Return the value of the local symbol symndx. - Address - local_symbol_value(unsigned int symndx) const; - + // Record that local symbol SYM needs a dynamic symbol entry. void set_needs_output_dynsym_entry(unsigned int sym) { @@ -1050,90 +2279,19 @@ class Sized_relobj : public Relobj this->local_values_[sym].set_needs_output_dynsym_entry(); } - // Return whether the local symbol SYMNDX has a GOT offset. - // For TLS symbols, the GOT entry will hold its tp-relative offset. + // Return whether the local symbol SYMNDX has a PLT offset. bool - local_has_got_offset(unsigned int symndx) const - { - return (this->local_got_offsets_.find(symndx) - != this->local_got_offsets_.end()); - } - - // Return the GOT offset of the local symbol SYMNDX. - unsigned int - local_got_offset(unsigned int symndx) const - { - Local_got_offsets::const_iterator p = - this->local_got_offsets_.find(symndx); - gold_assert(p != this->local_got_offsets_.end()); - return p->second; - } + local_has_plt_offset(unsigned int symndx) const; - // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET. + // Set the PLT offset of the local symbol SYMNDX. void - set_local_got_offset(unsigned int symndx, unsigned int got_offset) - { - std::pair ins = - this->local_got_offsets_.insert(std::make_pair(symndx, got_offset)); - gold_assert(ins.second); - } + set_local_plt_offset(unsigned int symndx, unsigned int plt_offset); - // Return whether the local TLS symbol SYMNDX has a GOT offset. - // The GOT entry at this offset will contain a module index. If - // NEED_PAIR is true, a second entry immediately following the first - // will contain the dtv-relative offset. + // Adjust this local symbol value. Return false if the symbol + // should be discarded from the output file. bool - local_has_tls_got_offset(unsigned int symndx, bool need_pair) const - { - typename Local_tls_got_offsets::const_iterator p = - this->local_tls_got_offsets_.find(symndx); - if (p == this->local_tls_got_offsets_.end() - || (need_pair && !p->second.have_pair_)) - return false; - return true; - } - - // Return the offset of the GOT entry for the local TLS symbol SYMNDX. - // If NEED_PAIR is true, we need the offset of a pair of GOT entries; - // otherwise we need the offset of the GOT entry for the module index. - unsigned int - local_tls_got_offset(unsigned int symndx, bool need_pair) const - { - typename Local_tls_got_offsets::const_iterator p = - this->local_tls_got_offsets_.find(symndx); - gold_assert(p != this->local_tls_got_offsets_.end()); - gold_assert(!need_pair || p->second.have_pair_); - return p->second.got_offset_; - } - - // Set the offset of the GOT entry for the local TLS symbol SYMNDX - // to GOT_OFFSET. If HAVE_PAIR is true, we have a pair of GOT entries; - // otherwise, we have just a single entry for the module index. - void - set_local_tls_got_offset(unsigned int symndx, unsigned int got_offset, - bool have_pair) - { - typename Local_tls_got_offsets::iterator p = - this->local_tls_got_offsets_.find(symndx); - if (p != this->local_tls_got_offsets_.end()) - { - // An entry already existed for this symbol. This can happen - // if we see a relocation asking for the module index before - // a relocation asking for the pair. In that case, the original - // GOT entry will remain, but won't get used by any further - // relocations. - p->second.got_offset_ = got_offset; - gold_assert(have_pair); - p->second.have_pair_ = true; - } - else - { - std::pair ins = - this->local_tls_got_offsets_.insert( - std::make_pair(symndx, Tls_got_entry(got_offset, have_pair))); - gold_assert(ins.second); - } - } + adjust_local_symbol(Symbol_value* 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 @@ -1142,32 +2300,116 @@ class Sized_relobj : public Relobj 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* lv_in, + Symbol_value* lv_out, + const Symbol_table* symtab); + + // Return true if the layout for this object was deferred. + bool is_deferred_layout() const + { return this->is_deferred_layout_; } + protected: + typedef typename Sized_relobj::Output_sections + Output_sections; + + // Set up. + virtual void + do_setup(); + // Read the symbols. void do_read_symbols(Read_symbols_data*); + // Read the symbols. This is common code for all target-specific + // overrides of do_read_symbols. + void + base_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* 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*); + 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(const General_options&, Symbol_table*, Layout*, - Read_relocs_data*); + do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*); // Count the local symbols. void @@ -1176,7 +2418,7 @@ class Sized_relobj : public Relobj // Finalize the local symbols. unsigned int - do_finalize_local_symbols(unsigned int, off_t); + do_finalize_local_symbols(unsigned int, off_t, Symbol_table*); // Set the offset where local dynamic symbol information will be stored. unsigned int @@ -1188,8 +2430,7 @@ class Sized_relobj : public Relobj // Relocate the input sections and write out the local symbols. void - do_relocate(const General_options& options, const Symbol_table* symtab, - const Layout*, Output_file* of); + do_relocate(const Symbol_table* symtab, const Layout*, Output_file* of); // Get the size of a section. uint64_t @@ -1198,18 +2439,36 @@ class Sized_relobj : public Relobj // Get the name of a section. std::string - do_section_name(unsigned int shndx) + do_section_name(unsigned int shndx) const { return this->elf_file_.section_name(shndx); } // Return the location of the contents of a section. - Object::Location - do_section_contents(unsigned int shndx) - { return this->elf_file_.section_contents(shndx); } + 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 this->elf_file_.section_flags(shndx); } + 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 @@ -1231,14 +2490,115 @@ class Sized_relobj : public Relobj 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* + 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::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 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*) 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 the output view for a section. + unsigned char* + do_get_output_view(unsigned int, section_size_type*) const; + private: // For convenience. - typedef Sized_relobj This; + typedef Sized_relobj_file This; static const int ehdr_size = elfcpp::Elf_sizes::ehdr_size; static const int shdr_size = elfcpp::Elf_sizes::shdr_size; static const int sym_size = elfcpp::Elf_sizes::sym_size; typedef elfcpp::Shdr 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 + Kept_comdat_section_table; + // Find the SHT_SYMTAB section, given the section headers. void find_symtab(const unsigned char* pshdrs); @@ -1257,83 +2617,199 @@ class Sized_relobj : public Relobj // Whether to include a section group in the link. bool include_section_group(Symbol_table*, Layout*, unsigned int, const char*, - const elfcpp::Shdr&, + const unsigned char*, const char*, section_size_type, std::vector*); // Whether to include a linkonce section in the link. bool - include_linkonce_section(Layout*, const char*, + include_linkonce_section(Layout*, unsigned int, const char*, const elfcpp::Shdr&); - // Views and sizes when relocating. - struct View_size - { - unsigned char* view; - typename elfcpp::Elf_types::Elf_Addr address; - off_t offset; - section_size_type view_size; - bool is_input_output_view; - bool is_postprocessing_view; - }; + // 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); - typedef std::vector Views; + // 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 unsigned char* pshdrs, Output_file*, Views*); + write_sections(const Layout*, const unsigned char* pshdrs, Output_file*, + Views*); // Relocate the sections in the output file. void - relocate_sections(const General_options& options, const Symbol_table*, - const Layout*, const unsigned char* pshdrs, Views*); + 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); } - // Initialize input to output maps for section symbols in merged - // sections. + // Reverse the words in a section. Used for .ctors sections mapped + // to .init_array sections. void - initialize_input_to_output_maps(); + reverse_words(unsigned char*, section_size_type); - // Free the input to output maps for section symbols in merged - // sections. + // Scan the input relocations for --emit-relocs. void - free_input_to_output_maps(); + 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 + 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 + void + incremental_relocs_scan_reltype( + const Read_relocs_data::Relocs_list::iterator&); + + void + incremental_relocs_write(const Relocate_info*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section*, + Address output_offset, + Output_file*); + + template + void + incremental_relocs_write_reltype(const Relocate_info*, + 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 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, + const Sized_target* target); + + template + 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, + const Sized_target* target); + + // 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*, - const Stringpool_template*); + const Stringpool_template*, + Output_symtab_xindex*, + Output_symtab_xindex*, + off_t); - // Clear the local symbol information. + // Record a mapping from discarded section SHNDX to the corresponding + // kept section. void - clear_local_symbols() + set_kept_comdat_section(unsigned int shndx, Relobj* kept_object, + unsigned int kept_shndx) { - this->local_values_.clear(); - this->local_got_offsets_.clear(); - this->local_tls_got_offsets_.clear(); + Kept_comdat_section kept(kept_object, kept_shndx); + this->kept_comdat_sections_.insert(std::make_pair(shndx, kept)); } - // The GOT offsets of local symbols. This map also stores GOT offsets - // for tp-relative offsets for TLS symbols. - typedef Unordered_map Local_got_offsets; + // 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; + } - // The TLS GOT offsets of local symbols. The map stores the offsets - // for either a single GOT entry that holds the module index of a TLS - // symbol, or a pair of GOT entries containing the module index and - // dtv-relative offset. - struct Tls_got_entry + // 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* lv_in, + Symbol_value* lv_out, + bool relocatable, + const Output_sections& out_sections, + const std::vector
& out_offsets, + const Symbol_table* symtab); + + // The PLT offsets of local symbols. + typedef Unordered_map Local_plt_offsets; + + // Saved information for sections whose layout was deferred. + struct Deferred_layout { - Tls_got_entry(int got_offset, bool have_pair) - : got_offset_(got_offset), - have_pair_(have_pair) - { } - int got_offset_; - bool have_pair_; + static const int shdr_size = elfcpp::Elf_sizes::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]; }; - typedef Unordered_map Local_tls_got_offsets; // General access to the ELF file. elfcpp::Elf_file 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. @@ -1345,20 +2821,32 @@ class Sized_relobj : public Relobj unsigned int output_local_dynsym_count_; // The entries in the symbol table for the external symbols. Symbols symbols_; - // File offset for local 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. + // File offset for local dynamic symbols (absolute). off_t local_dynsym_offset_; // Values of local symbols. Local_values local_values_; - // GOT offsets for local non-TLS symbols, and tp-relative offsets - // for TLS symbols, indexed by symbol number. - Local_got_offsets local_got_offsets_; - // GOT offsets for local TLS symbols, indexed by symbol number - // and GOT entry type. - Local_tls_got_offsets local_tls_got_offsets_; + // 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_; + // True if the layout of this object was deferred, waiting for plugin + // replacement files. + bool is_deferred_layout_; + // The list of sections whose layout was deferred. + std::vector deferred_layout_; + // The list of relocation sections whose layout was deferred. + std::vector deferred_layout_relocs_; + // Pointer to the list of output views; valid only during do_relocate(). + const Views* output_views_; }; // A class to manage the list of all objects. @@ -1367,8 +2855,7 @@ class Input_objects { public: Input_objects() - : relobj_list_(), dynobj_list_(), target_(NULL), sonames_(), - system_library_directory_() + : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL) { } // The type of the list of input relocateable objects. @@ -1384,10 +2871,13 @@ class Input_objects bool add_object(Object*); - // Get the target we should use for the output file. - Target* - target() const - { return this->target_; } + // 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. @@ -1399,6 +2889,14 @@ class Input_objects 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 @@ -1424,6 +2922,11 @@ class Input_objects 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 @@ -1437,12 +2940,10 @@ class Input_objects Relobj_list relobj_list_; // The list of dynamic objects included in the link. Dynobj_list dynobj_list_; - // The target. - Target* target_; // SONAMEs that we have seen. - Unordered_set sonames_; - // The directory in which we find the libc.so. - std::string system_library_directory_; + Unordered_map sonames_; + // Manage cross-references if requested. + Cref* cref_; }; // Some of the information we pass to the relocation routines. We @@ -1451,18 +2952,22 @@ class Input_objects template struct Relocate_info { - // Command line options. - const General_options* options; // Symbol table. const Symbol_table* symtab; // Layout. const Layout* layout; // Object being relocated. - Sized_relobj* object; + Sized_relobj_file* object; // Section index of relocation section. unsigned int reloc_shndx; + // Section header of relocation section. + const unsigned char* reloc_shdr; + // Info about how relocs should be handled + Relocatable_relocs* rr; // 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. @@ -1470,13 +2975,49 @@ struct Relocate_info 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 Section_id; + +// This is similar to Section_id but is used when the section +// pointers are const. +typedef std::pair 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(loc.first) ^ loc.second; } +}; + +struct Const_section_id_hash +{ + size_t operator()(const Const_section_id& loc) const + { return reinterpret_cast(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. +// 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); + section_offset_type bytes, bool* punconfigured); } // end namespace gold