X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fobject.h;h=187a10179b558c41a925af22d6be127228b0e4db;hb=2ea97941102380c28117882600265c1187c6fc8b;hp=8a51550b37d6f43f0c7a669c78882d763837d633;hpb=7d1a9ebbf2b6018657e88172df4356ad4733b9c6;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/object.h b/gold/object.h index 8a51550b37..187a10179b 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 2006, 2007, 2008, 2009 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -36,12 +36,17 @@ namespace gold class General_options; class Task; +class Cref; +class Archive; class Layout; class Output_section; class Output_file; +class Output_symtab_xindex; +class Pluginobj; class Dynobj; class Object_merge_map; class Relocatable_relocs; +class Symbols_data; template class Stringpool_template; @@ -127,6 +132,55 @@ 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_; +}; + // 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). @@ -141,7 +195,8 @@ 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) + is_dynamic_(is_dynamic), is_needed_(false), uses_split_stack_(false), + has_no_split_stack_(false), no_export_(false), xindex_(NULL) { input_file->file().add_object(); } virtual ~Object() @@ -162,10 +217,44 @@ class Object is_dynamic() const { return this->is_dynamic_; } - // Return the target structure associated with this object. - Target* - target() const - { return this->target_; } + // 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 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() + { return this->input_file_; } + + const Input_file* + input_file() const + { return this->input_file_; } // Lock the underlying file. void @@ -197,13 +286,6 @@ class Object just_symbols() const { return this->input_file()->just_symbols(); } - // 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() const; - // Get the number of sections. unsigned int shnum() const @@ -214,6 +296,29 @@ 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) @@ -229,6 +334,11 @@ 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) @@ -267,8 +377,8 @@ 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); } // Functions and types for the elfcpp::Elf_file interface. This // permit us to use Object as the File template parameter for @@ -295,7 +405,7 @@ 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 @@ -314,27 +424,28 @@ 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. @@ -347,7 +458,39 @@ class Object clear_view_cache_marks() { 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); } + + // Return whether this object was found in a system directory. + bool + is_in_system_directory() const + { return this->input_file()->is_in_system_directory(); } + + // 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; } + protected: + // Returns NULL for Objects that are not plugin objects. This method + // is overridden in the Pluginobj class. + virtual Pluginobj* + do_pluginobj() + { return NULL; } + // Read the symbols--implemented by child class. virtual void do_read_symbols(Read_symbols_data*) = 0; @@ -359,7 +502,7 @@ 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; // Return the location of the contents of a section. Implemented by // child class. @@ -378,6 +521,10 @@ class Object 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; @@ -398,19 +545,13 @@ 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 Xindex structure to use. + virtual Xindex* + do_initialize_xindex() = 0; - const Input_file* - input_file() const - { return this->input_file_; } - - // Set the target. - void - set_target(int machine, int size, bool big_endian, int osabi, - int abiversion); + // 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; // Set the number of sections. void @@ -425,6 +566,14 @@ class Object read_section_data(elfcpp::Elf_file*, Read_symbols_data*); + // 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. @@ -432,6 +581,12 @@ 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 -fstack-split, mark it accordingly, + // and return true. Otherwise return false. + bool + handle_split_stack_section(const char* name); + private: // This class may not be copied. Object(const Object&); @@ -447,23 +602,23 @@ 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; + // Many sections for objects with more than SHN_LORESERVE sections. + Xindex* xindex_; }; -// 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() 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. @@ -472,22 +627,62 @@ 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) { } + // 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); } // The number of local symbols in the input symbol table. virtual unsigned int @@ -506,8 +701,8 @@ 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 @@ -521,43 +716,38 @@ class Relobj : public Object // 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 + // 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* + output_section(unsigned int shndx) const { - gold_assert(shndx < this->map_to_output_.size()); - return (this->map_to_output_[shndx].output_section != NULL - && this->map_to_output_[shndx].offset == -1); + gold_assert(shndx < this->output_sections_.size()); + return this->output_sections_[shndx]; } - // 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; + // 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); } // 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 @@ -596,28 +786,29 @@ 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); } + 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 number of local symbols--implemented by child class. virtual unsigned int @@ -632,7 +823,7 @@ 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 @@ -645,17 +836,29 @@ 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; + + // Get the offset of a section--implemented by child class. + virtual uint64_t + do_output_section_offset(unsigned int shndx) const = 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; // 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 @@ -673,7 +876,7 @@ class Relobj : public Object 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_; @@ -683,18 +886,15 @@ 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_; }; -// 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. @@ -734,13 +934,36 @@ 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: @@ -773,8 +996,8 @@ 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), has_output_value_(true) { this->u_.value = 0; } // Get the value of this symbol. OBJECT is the object in which this @@ -786,8 +1009,11 @@ class Symbol_value 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. @@ -813,7 +1039,7 @@ 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_); } @@ -836,7 +1062,7 @@ 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; } @@ -907,18 +1133,22 @@ class Symbol_value // Set the index of the input section in the input file. void - set_input_shndx(unsigned int i) + 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() const - { return this->input_shndx_; } + input_shndx(bool* is_ordinary) const + { + *is_ordinary = this->is_ordinary_shndx_; + return this->input_shndx_; + } // Whether this is a section symbol. bool @@ -952,7 +1182,10 @@ class Symbol_value unsigned int output_dynsym_index_; // The section index in the input file in which this symbol is // defined. - unsigned int input_shndx_ : 29; + unsigned int input_shndx_ : 28; + // 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. @@ -976,6 +1209,107 @@ class Symbol_value } u_; }; +// 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; + } + + private: + unsigned int got_type_; + unsigned int got_offset_; + Got_offset_list* got_next_; +}; + +// 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_; +}; + // A regular object file. This is size and endian specific. template @@ -986,14 +1320,29 @@ class Sized_relobj : public Relobj typedef std::vector Symbols; typedef std::vector > Local_values; + static const Address invalid_address = static_cast
(0) - 1; + Sized_relobj(const std::string& name, Input_file* input_file, off_t offset, const typename elfcpp::Ehdr&); ~Sized_relobj(); - // Set up the object file based on the ELF header. + // 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; } + + // Set up the object file based on TARGET. void - setup(const typename elfcpp::Ehdr&); + setup() + { this->do_setup(); } + + // 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. @@ -1009,12 +1358,13 @@ 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. @@ -1045,21 +1395,13 @@ 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() - { return this->Object::sized_target(); } - - // 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) { @@ -1070,88 +1412,55 @@ class Sized_relobj : public Relobj // Return whether the local symbol SYMNDX has a GOT offset. // For TLS symbols, the GOT entry will hold its tp-relative offset. bool - local_has_got_offset(unsigned int symndx) const + local_has_got_offset(unsigned int symndx, unsigned int got_type) const { - return (this->local_got_offsets_.find(symndx) - != this->local_got_offsets_.end()); + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(symndx); + return (p != this->local_got_offsets_.end() + && p->second->get_offset(got_type) != -1U); } // Return the GOT offset of the local symbol SYMNDX. unsigned int - local_got_offset(unsigned int symndx) const + local_got_offset(unsigned int symndx, unsigned int got_type) const { Local_got_offsets::const_iterator p = this->local_got_offsets_.find(symndx); gold_assert(p != this->local_got_offsets_.end()); - return p->second; + unsigned int off = p->second->get_offset(got_type); + gold_assert(off != -1U); + return off; } // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET. void - set_local_got_offset(unsigned int symndx, unsigned int got_offset) - { - std::pair ins = - this->local_got_offsets_.insert(std::make_pair(symndx, got_offset)); - gold_assert(ins.second); - } - - // Return whether the local TLS symbol SYMNDX has a GOT offset. - // The GOT entry at this offset will contain a module index. If - // NEED_PAIR is true, a second entry immediately following the first - // will contain the dtv-relative offset. - bool - local_has_tls_got_offset(unsigned int symndx, bool need_pair) const + set_local_got_offset(unsigned int symndx, unsigned int got_type, + unsigned int got_offset) { - 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; - } + Local_got_offsets::const_iterator p = + this->local_got_offsets_.find(symndx); + if (p != this->local_got_offsets_.end()) + p->second->set_offset(got_type, got_offset); else { - std::pair ins = - this->local_tls_got_offsets_.insert( - std::make_pair(symndx, Tls_got_entry(got_offset, have_pair))); + Got_offset_list* g = new Got_offset_list(got_type, got_offset); + std::pair ins = + this->local_got_offsets_.insert(std::make_pair(symndx, g)); gold_assert(ins.second); } } + // 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]; + } + // Return the name of the symbol that spans the given offset in the // specified section in this object. This is used only for error // messages and is not particularly efficient. @@ -1159,7 +1468,22 @@ 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; + + // Make section offset invalid. This is needed for relaxation. + void + invalidate_section_offset(unsigned int shndx) + { this->do_invalidate_section_offset(shndx); } + protected: + // Set up. + virtual void + do_setup(); + // Read the symbols. void do_read_symbols(Read_symbols_data*); @@ -1173,18 +1497,27 @@ class Sized_relobj : public Relobj 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*); // 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 @@ -1193,7 +1526,7 @@ 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 @@ -1205,8 +1538,7 @@ 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 @@ -1225,8 +1557,11 @@ class Sized_relobj : public Relobj // 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 @@ -1253,6 +1588,92 @@ 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 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] = convert_types(off); + } + + // Set the offset of a section to invalid_address. + virtual void + do_invalidate_section_offset(unsigned int shndx) + { + gold_assert(shndx < this->section_offsets_.size()); + this->section_offsets_[shndx] = invalid_address; + } + + // 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; + }; + + typedef std::vector Views; + + // This may be overriden by a child class. + virtual void + do_relocate_sections(const Symbol_table* symtab, const Layout* layout, + const unsigned char* pshdrs, Views* pviews); + private: // For convenience. typedef Sized_relobj This; @@ -1261,6 +1682,20 @@ class Sized_relobj : public Relobj 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); @@ -1279,26 +1714,19 @@ 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; - }; - - typedef std::vector Views; + // Layout an input section. + void + layout_section(Layout* layout, unsigned int shndx, const char* name, + typename This::Shdr& 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. @@ -1307,20 +1735,20 @@ class Sized_relobj : public Relobj // 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, Views* pviews) + { this->do_relocate_sections(symtab, layout, pshdrs, pviews); } // Scan the input relocations for --emit-relocs. void - emit_relocs_scan(const General_options&, Symbol_table*, Layout*, - const unsigned char* plocal_syms, + 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(const General_options&, Symbol_table*, Layout*, + emit_relocs_scan_reltype(Symbol_table*, Layout*, const unsigned char* plocal_syms, const Read_relocs_data::Relocs_list::iterator&, Relocatable_relocs*); @@ -1329,7 +1757,7 @@ class Sized_relobj : public Relobj void emit_relocs(const Relocate_info*, unsigned int, unsigned int sh_type, const unsigned char* prelocs, - size_t reloc_count, Output_section*, off_t output_offset, + size_t reloc_count, Output_section*, Address output_offset, unsigned char* view, Address address, section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size); @@ -1340,27 +1768,43 @@ class Sized_relobj : public Relobj void emit_relocs_reltype(const Relocate_info*, unsigned int, const unsigned char* prelocs, size_t reloc_count, - Output_section*, off_t output_offset, + Output_section*, Address output_offset, unsigned char* view, Address address, section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size); - // Initialize input to output maps for section symbols in merged - // sections. + // 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 - initialize_input_to_output_maps(); + 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); - // Free the input to output maps for section symbols in merged - // sections. + template void - free_input_to_output_maps(); + split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs, + unsigned int shndx, const unsigned char* prelocs, + size_t reloc_count, unsigned char* view, + section_size_type view_size, + Reloc_symbol_changes** reloc_map); + + // Find all functions in a section. + void + find_functions(const unsigned char* pshdrs, unsigned int shndx, + Function_offsets*); // Write out the local symbols. void write_local_symbols(Output_file*, const Stringpool_template*, - const Stringpool_template*); + const Stringpool_template*, + Output_symtab_xindex*, + Output_symtab_xindex*); // Clear the local symbol information. void @@ -1368,12 +1812,36 @@ class Sized_relobj : public Relobj { this->local_values_.clear(); this->local_got_offsets_.clear(); - this->local_tls_got_offsets_.clear(); + } + + // Record a mapping from discarded section SHNDX to the corresponding + // kept section. + void + set_kept_comdat_section(unsigned int shndx, Relobj* kept_object, + unsigned int kept_shndx) + { + Kept_comdat_section kept(kept_object, kept_shndx); + this->kept_comdat_sections_.insert(std::make_pair(shndx, kept)); + } + + // Find the kept section corresponding to the discarded section + // SHNDX. Return true if found. + bool + get_kept_comdat_section(unsigned int shndx, Relobj** kept_object, + unsigned int* kept_shndx) const + { + typename Kept_comdat_section_table::const_iterator p = + this->kept_comdat_sections_.find(shndx); + if (p == this->kept_comdat_sections_.end()) + return false; + *kept_object = p->second.object; + *kept_shndx = p->second.shndx; + return true; } // 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; + typedef Unordered_map Local_got_offsets; // The TLS GOT offsets of local symbols. The map stores the offsets // for either a single GOT entry that holds the module index of a TLS @@ -1390,6 +1858,25 @@ class Sized_relobj : public Relobj }; typedef Unordered_map Local_tls_got_offsets; + // Saved information for sections whose layout was deferred. + struct Deferred_layout + { + 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]; + }; + // General access to the ELF file. elfcpp::Elf_file elf_file_; // Index of SHT_SYMTAB section. @@ -1403,6 +1890,8 @@ class Sized_relobj : public Relobj unsigned int output_local_dynsym_count_; // The entries in the symbol table for the external symbols. Symbols symbols_; + // Number of symbols defined in object file itself. + size_t defined_count_; // File offset for local symbols. off_t local_symbol_offset_; // File offset for local dynamic symbols. @@ -1412,11 +1901,19 @@ class Sized_relobj : public Relobj // 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_; + // 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_; + // Table mapping discarded comdat sections to corresponding kept sections. + Kept_comdat_section_table kept_comdat_sections_; // Whether this object has a GNU style .eh_frame section. bool has_eh_frame_; + // If this object has a GNU style .eh_frame section that is discarded in + // output, record the index here. Otherwise it is -1U. + unsigned int discarded_eh_frame_shndx_; + // The list of sections whose layout was deferred. + std::vector deferred_layout_; }; // A class to manage the list of all objects. @@ -1425,7 +1922,7 @@ class Input_objects { public: Input_objects() - : relobj_list_(), dynobj_list_(), sonames_(), system_library_directory_() + : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL) { } // The type of the list of input relocateable objects. @@ -1441,6 +1938,14 @@ class Input_objects bool add_object(Object*); + // Start processing an archive. + void + archive_start(Archive*); + + // Stop processing an archive. + void + archive_stop(Archive*); + // For each dynamic object, check whether we've seen all of its // explicit dependencies. void @@ -1451,6 +1956,10 @@ class Input_objects bool found_in_system_library_directory(const Object*) const; + // Print symbol counts. + void + print_symbol_counts(const Symbol_table*) const; + // Iterate over all regular objects. Relobj_iterator @@ -1491,8 +2000,8 @@ class Input_objects Dynobj_list dynobj_list_; // SONAMEs that we have seen. Unordered_set sonames_; - // The directory in which we find the libc.so. - std::string system_library_directory_; + // Manage cross-references if requested. + Cref* cref_; }; // Some of the information we pass to the relocation routines. We @@ -1501,8 +2010,6 @@ class Input_objects template struct Relocate_info { - // Command line options. - const General_options* options; // Symbol table. const Symbol_table* symtab; // Layout. @@ -1511,8 +2018,12 @@ struct Relocate_info Sized_relobj* object; // Section index of relocation section. unsigned int reloc_shndx; + // Section header of relocation section. + const unsigned char* reloc_shdr; // Section index of section being relocated. unsigned int data_shndx; + // Section header of data section. + const unsigned char* data_shdr; // Return a string showing the location of a relocation. This is // only used for error messages. @@ -1520,13 +2031,24 @@ struct Relocate_info location(size_t relnum, off_t reloffset) const; }; +// 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