--- /dev/null
+// object.h -- support for an object file for linking in gold -*- C++ -*-
+
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#ifndef GOLD_OBJECT_H
+#define GOLD_OBJECT_H
+
+#include <string>
+#include <vector>
+
+#include "elfcpp.h"
+#include "elfcpp_file.h"
+#include "fileread.h"
+#include "target.h"
+
+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<typename Stringpool_char>
+class Stringpool_template;
+
+// Data to pass from read_symbols() to add_symbols().
+
+struct Read_symbols_data
+{
+ // Section headers.
+ File_view* section_headers;
+ // Section names.
+ File_view* section_names;
+ // Size of section name data in bytes.
+ section_size_type section_names_size;
+ // Symbol data.
+ File_view* symbols;
+ // Size of symbol data in bytes.
+ section_size_type symbols_size;
+ // Offset of external symbols within symbol data. This structure
+ // sometimes contains only external symbols, in which case this will
+ // be zero. Sometimes it contains all symbols.
+ section_offset_type external_symbols_offset;
+ // Symbol names.
+ File_view* symbol_names;
+ // Size of symbol name data in bytes.
+ section_size_type symbol_names_size;
+
+ // Version information. This is only used on dynamic objects.
+ // Version symbol data (from SHT_GNU_versym section).
+ File_view* versym;
+ section_size_type versym_size;
+ // Version definition data (from SHT_GNU_verdef section).
+ File_view* verdef;
+ section_size_type verdef_size;
+ unsigned int verdef_info;
+ // Needed version data (from SHT_GNU_verneed section).
+ File_view* verneed;
+ section_size_type verneed_size;
+ unsigned int verneed_info;
+};
+
+// Information used to print error messages.
+
+struct Symbol_location_info
+{
+ std::string source_file;
+ std::string enclosing_symbol_name;
+ int line_number;
+};
+
+// Data about a single relocation section. This is read in
+// read_relocs and processed in scan_relocs.
+
+struct Section_relocs
+{
+ // Index of reloc section.
+ unsigned int reloc_shndx;
+ // Index of section that relocs apply to.
+ unsigned int data_shndx;
+ // Contents of reloc section.
+ File_view* contents;
+ // Reloc section type.
+ unsigned int sh_type;
+ // Number of reloc entries.
+ size_t reloc_count;
+ // Output section.
+ Output_section* output_section;
+ // Whether this section has special handling for offsets.
+ bool needs_special_offset_handling;
+ // Whether the data section is allocated (has the SHF_ALLOC flag set).
+ bool is_data_section_allocated;
+};
+
+// Relocations in an object file. This is read in read_relocs and
+// processed in scan_relocs.
+
+struct Read_relocs_data
+{
+ typedef std::vector<Section_relocs> Relocs_list;
+ // The relocations.
+ Relocs_list relocs;
+ // The local symbols.
+ File_view* local_symbols;
+};
+
+// The Xindex class manages section indexes for objects with more than
+// 0xff00 sections.
+
+class Xindex
+{
+ public:
+ Xindex(int large_shndx_offset)
+ : large_shndx_offset_(large_shndx_offset), symtab_xindex_()
+ { }
+
+ // Initialize the symtab_xindex_ array, given the object and the
+ // section index of the symbol table to use.
+ template<int size, bool big_endian>
+ void
+ initialize_symtab_xindex(Object*, unsigned int symtab_shndx);
+
+ // Read in the symtab_xindex_ array, given its section index.
+ // PSHDRS may optionally point to the section headers.
+ template<int size, bool big_endian>
+ void
+ read_symtab_xindex(Object*, unsigned int xindex_shndx,
+ const unsigned char* pshdrs);
+
+ // Symbol SYMNDX in OBJECT has a section of SHN_XINDEX; return the
+ // real section index.
+ unsigned int
+ sym_xindex_to_shndx(Object* object, unsigned int symndx);
+
+ private:
+ // The type of the array giving the real section index for symbols
+ // whose st_shndx field holds SHN_XINDEX.
+ typedef std::vector<unsigned int> Symtab_xindex;
+
+ // Adjust a section index if necessary. This should only be called
+ // for ordinary section indexes.
+ unsigned int
+ adjust_shndx(unsigned int shndx)
+ {
+ if (shndx >= elfcpp::SHN_LORESERVE)
+ shndx += this->large_shndx_offset_;
+ return shndx;
+ }
+
+ // Adjust to apply to large section indexes.
+ int large_shndx_offset_;
+ // The data from the SHT_SYMTAB_SHNDX section.
+ Symtab_xindex symtab_xindex_;
+};
+
+// Object is an abstract base class which represents either a 32-bit
+// or a 64-bit input object. This can be a regular object file
+// (ET_REL) or a shared object (ET_DYN).
+
+class Object
+{
+ public:
+ // NAME is the name of the object as we would report it to the user
+ // (e.g., libfoo.a(bar.o) if this is in an archive. INPUT_FILE is
+ // used to read the file. OFFSET is the offset within the input
+ // file--0 for a .o or .so file, something else for a .a file.
+ Object(const std::string& name, Input_file* input_file, bool is_dynamic,
+ off_t offset = 0)
+ : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
+ is_dynamic_(is_dynamic), uses_split_stack_(false),
+ has_no_split_stack_(false), xindex_(NULL), no_export_(false)
+ { input_file->file().add_object(); }
+
+ virtual ~Object()
+ { this->input_file_->file().remove_object(); }
+
+ // Return the name of the object as we would report it to the tuser.
+ const std::string&
+ name() const
+ { return this->name_; }
+
+ // Get the offset into the file.
+ off_t
+ offset() const
+ { return this->offset_; }
+
+ // Return whether this is a dynamic object.
+ bool
+ is_dynamic() const
+ { return this->is_dynamic_; }
+
+ // Return whether this object 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
+ lock(const Task* t)
+ { this->input_file()->file().lock(t); }
+
+ // Unlock the underlying file.
+ void
+ unlock(const Task* t)
+ { this->input_file()->file().unlock(t); }
+
+ // Return whether the underlying file is locked.
+ bool
+ is_locked() const
+ { return this->input_file()->file().is_locked(); }
+
+ // Return the token, so that the task can be queued.
+ Task_token*
+ token()
+ { return this->input_file()->file().token(); }
+
+ // Release the underlying file.
+ void
+ release()
+ { this->input_file_->file().release(); }
+
+ // Return whether we should just read symbols from this file.
+ bool
+ just_symbols() const
+ { return this->input_file()->just_symbols(); }
+
+ // Get the number of sections.
+ unsigned int
+ shnum() const
+ { return this->shnum_; }
+
+ // Return a view of the contents of a section. Set *PLEN to the
+ // size. CACHE is a hint as in File_read::get_view.
+ const unsigned char*
+ section_contents(unsigned int shndx, section_size_type* plen, bool cache);
+
+ // Adjust a symbol's section index as needed. SYMNDX is the index
+ // of the symbol and SHNDX is the symbol's section from
+ // get_st_shndx. This returns the section index. It sets
+ // *IS_ORDINARY to indicate whether this is a normal section index,
+ // rather than a special code between SHN_LORESERVE and
+ // SHN_HIRESERVE.
+ unsigned int
+ adjust_sym_shndx(unsigned int symndx, unsigned int shndx, bool* is_ordinary)
+ {
+ if (shndx < elfcpp::SHN_LORESERVE)
+ *is_ordinary = true;
+ else if (shndx == elfcpp::SHN_XINDEX)
+ {
+ if (this->xindex_ == NULL)
+ this->xindex_ = this->do_initialize_xindex();
+ shndx = this->xindex_->sym_xindex_to_shndx(this, symndx);
+ *is_ordinary = true;
+ }
+ else
+ *is_ordinary = false;
+ return shndx;
+ }
+
+ // Return the size of a section given a section index.
+ uint64_t
+ section_size(unsigned int shndx)
+ { return this->do_section_size(shndx); }
+
+ // Return the name of a section given a section index.
+ std::string
+ section_name(unsigned int shndx)
+ { return this->do_section_name(shndx); }
+
+ // Return the section flags given a section index.
+ uint64_t
+ section_flags(unsigned int shndx)
+ { return this->do_section_flags(shndx); }
+
+ // Return the section entsize given a section index.
+ uint64_t
+ section_entsize(unsigned int shndx)
+ { return this->do_section_entsize(shndx); }
+
+ // Return the section address given a section index.
+ uint64_t
+ section_address(unsigned int shndx)
+ { return this->do_section_address(shndx); }
+
+ // Return the section type given a section index.
+ unsigned int
+ section_type(unsigned int shndx)
+ { return this->do_section_type(shndx); }
+
+ // Return the section link field given a section index.
+ unsigned int
+ section_link(unsigned int shndx)
+ { return this->do_section_link(shndx); }
+
+ // Return the section info field given a section index.
+ unsigned int
+ section_info(unsigned int shndx)
+ { return this->do_section_info(shndx); }
+
+ // Return the required section alignment given a section index.
+ uint64_t
+ section_addralign(unsigned int shndx)
+ { return this->do_section_addralign(shndx); }
+
+ // Read the symbol information.
+ void
+ read_symbols(Read_symbols_data* sd)
+ { return this->do_read_symbols(sd); }
+
+ // Pass sections which should be included in the link to the Layout
+ // object, and record where the sections go in the output file.
+ void
+ layout(Symbol_table* symtab, Layout* layout, Read_symbols_data* sd)
+ { this->do_layout(symtab, layout, sd); }
+
+ // Add symbol information to the global symbol table.
+ void
+ add_symbols(Symbol_table* symtab, Read_symbols_data* sd, Layout *layout)
+ { this->do_add_symbols(symtab, sd, layout); }
+
+ // Functions and types for the elfcpp::Elf_file interface. This
+ // permit us to use Object as the File template parameter for
+ // elfcpp::Elf_file.
+
+ // The View class is returned by view. It must support a single
+ // method, data(). This is trivial, because get_view does what we
+ // need.
+ class View
+ {
+ public:
+ View(const unsigned char* p)
+ : p_(p)
+ { }
+
+ const unsigned char*
+ data() const
+ { return this->p_; }
+
+ private:
+ const unsigned char* p_;
+ };
+
+ // Return a View.
+ View
+ view(off_t file_offset, section_size_type data_size)
+ { return View(this->get_view(file_offset, data_size, true, true)); }
+
+ // Report an error.
+ void
+ error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
+
+ // A location in the file.
+ struct Location
+ {
+ off_t file_offset;
+ off_t data_size;
+
+ Location(off_t fo, section_size_type ds)
+ : file_offset(fo), data_size(ds)
+ { }
+ };
+
+ // Get a View given a Location.
+ View view(Location loc)
+ { return View(this->get_view(loc.file_offset, loc.data_size, true, true)); }
+
+ // Get a view into the underlying file.
+ const unsigned char*
+ get_view(off_t start, section_size_type size, bool aligned, bool cache)
+ {
+ return this->input_file()->file().get_view(this->offset_, start, size,
+ aligned, cache);
+ }
+
+ // Get a lasting view into the underlying file.
+ File_view*
+ get_lasting_view(off_t start, section_size_type size, bool aligned,
+ bool cache)
+ {
+ return this->input_file()->file().get_lasting_view(this->offset_, start,
+ size, aligned, cache);
+ }
+
+ // Read data from the underlying file.
+ void
+ read(off_t start, section_size_type size, void* p)
+ { this->input_file()->file().read(start + this->offset_, size, p); }
+
+ // Read multiple data from the underlying file.
+ void
+ read_multiple(const File_read::Read_multiple& rm)
+ { this->input_file()->file().read_multiple(this->offset_, rm); }
+
+ // Stop caching views in the underlying file.
+ void
+ clear_view_cache_marks()
+ { 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;
+
+ // Lay out sections--implemented by child class.
+ virtual void
+ do_layout(Symbol_table*, Layout*, Read_symbols_data*) = 0;
+
+ // Add symbol information to the global symbol table--implemented by
+ // child class.
+ virtual void
+ do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*) = 0;
+
+ // Return the location of the contents of a section. Implemented by
+ // child class.
+ virtual Location
+ do_section_contents(unsigned int shndx) = 0;
+
+ // Get the size of a section--implemented by child class.
+ virtual uint64_t
+ do_section_size(unsigned int shndx) = 0;
+
+ // Get the name of a section--implemented by child class.
+ virtual std::string
+ do_section_name(unsigned int shndx) = 0;
+
+ // Get section flags--implemented by child class.
+ virtual uint64_t
+ do_section_flags(unsigned int shndx) = 0;
+
+ // Get section entsize--implemented by child class.
+ virtual uint64_t
+ do_section_entsize(unsigned int shndx) = 0;
+
+ // Get section address--implemented by child class.
+ virtual uint64_t
+ do_section_address(unsigned int shndx) = 0;
+
+ // Get section type--implemented by child class.
+ virtual unsigned int
+ do_section_type(unsigned int shndx) = 0;
+
+ // Get section link field--implemented by child class.
+ virtual unsigned int
+ do_section_link(unsigned int shndx) = 0;
+
+ // Get section info field--implemented by child class.
+ virtual unsigned int
+ do_section_info(unsigned int shndx) = 0;
+
+ // Get section alignment--implemented by child class.
+ virtual uint64_t
+ do_section_addralign(unsigned int shndx) = 0;
+
+ // Return the 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;
+
+ // Set the number of sections.
+ void
+ set_shnum(int shnum)
+ { this->shnum_ = shnum; }
+
+ // Functions used by both Sized_relobj and Sized_dynobj.
+
+ // Read the section data into a Read_symbols_data object.
+ template<int size, bool big_endian>
+ void
+ read_section_data(elfcpp::Elf_file<size, big_endian, Object>*,
+ Read_symbols_data*);
+
+ // Let the child class initialize the xindex object directly.
+ void
+ set_xindex(Xindex* xindex)
+ {
+ gold_assert(this->xindex_ == NULL);
+ this->xindex_ = xindex;
+ }
+
+ // If NAME is the name of a special .gnu.warning section, arrange
+ // for the warning to be issued. SHNDX is the section index.
+ // Return whether it is a warning section.
+ bool
+ handle_gnu_warning_section(const char* name, unsigned int shndx,
+ Symbol_table*);
+
+ // If NAME is the name of the special section which indicates that
+ // this object was compiled with -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&);
+ Object& operator=(const Object&);
+
+ // Name of object as printed to user.
+ std::string name_;
+ // For reading the file.
+ Input_file* input_file_;
+ // Offset within the file--0 for an object file, non-0 for an
+ // archive.
+ off_t offset_;
+ // Number of input sections.
+ unsigned int shnum_;
+ // Whether this is a dynamic object.
+ bool is_dynamic_;
+ // Whether this object was compiled with -fsplit-stack.
+ bool uses_split_stack_;
+ // Whether this object contains any functions compiled with the
+ // no_split_stack attribute.
+ bool has_no_split_stack_;
+ // Many sections for objects with more than SHN_LORESERVE sections.
+ Xindex* xindex_;
+ // True if exclude this object from automatic symbol export.
+ // This is used only for archive objects.
+ bool no_export_;
+};
+
+// A regular object (ET_REL). This is an abstract base class itself.
+// The implementation is the template class Sized_relobj.
+
+class Relobj : public Object
+{
+ public:
+ Relobj(const std::string& name, Input_file* input_file, off_t offset = 0)
+ : Object(name, input_file, false, offset),
+ output_sections_(),
+ map_to_relocatable_relocs_(NULL),
+ object_merge_map_(NULL),
+ 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(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Read_relocs_data* rd)
+ { return this->do_gc_process_relocs(options, 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); }
+
+ // The number of local symbols in the input symbol table.
+ virtual unsigned int
+ local_symbol_count() const
+ { return this->do_local_symbol_count(); }
+
+ // Initial local symbol processing: count the number of local symbols
+ // in the output symbol table and dynamic symbol table; add local symbol
+ // names to *POOL and *DYNPOOL.
+ void
+ count_local_symbols(Stringpool_template<char>* pool,
+ Stringpool_template<char>* dynpool)
+ { return this->do_count_local_symbols(pool, dynpool); }
+
+ // Set the values of the local symbols, set the output symbol table
+ // indexes for the local variables, and set the offset where local
+ // symbol information will be stored. Returns the new local symbol index.
+ unsigned int
+ finalize_local_symbols(unsigned int index, off_t off, Symbol_table* symtab)
+ { return this->do_finalize_local_symbols(index, off, symtab); }
+
+ // Set the output dynamic symbol table indexes for the local variables.
+ unsigned int
+ set_local_dynsym_indexes(unsigned int index)
+ { return this->do_set_local_dynsym_indexes(index); }
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ set_local_dynsym_offset(off_t off)
+ { return this->do_set_local_dynsym_offset(off); }
+
+ // Relocate the input sections and write out the local symbols.
+ void
+ relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout* layout, Output_file* of)
+ { return this->do_relocate(options, symtab, layout, of); }
+
+ // Return whether an input section is being included in the link.
+ bool
+ is_section_included(unsigned int shndx) const
+ {
+ gold_assert(shndx < this->output_sections_.size());
+ return this->output_sections_[shndx] != NULL;
+ }
+
+ // 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->output_sections_.size());
+ return this->output_sections_[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); }
+
+ // Set the offset of an input section within its output section.
+ void
+ set_section_offset(unsigned int shndx, uint64_t off)
+ { this->do_set_section_offset(shndx, off); }
+
+ // Return true if we need to wait for output sections to be written
+ // before we can apply relocations. This is true if the object has
+ // any relocations for sections which require special handling, such
+ // as the exception frame section.
+ bool
+ relocs_must_follow_section_writes() const
+ { return this->relocs_must_follow_section_writes_; }
+
+ // Return the object merge map.
+ Object_merge_map*
+ merge_map() const
+ { return this->object_merge_map_; }
+
+ // Set the object merge map.
+ void
+ set_merge_map(Object_merge_map* object_merge_map)
+ {
+ gold_assert(this->object_merge_map_ == NULL);
+ this->object_merge_map_ = object_merge_map;
+ }
+
+ // Record the relocatable reloc info for an input reloc section.
+ void
+ set_relocatable_relocs(unsigned int reloc_shndx, Relocatable_relocs* rr)
+ {
+ gold_assert(reloc_shndx < this->shnum());
+ (*this->map_to_relocatable_relocs_)[reloc_shndx] = rr;
+ }
+
+ // Get the relocatable reloc info for an input reloc section.
+ Relocatable_relocs*
+ relocatable_relocs(unsigned int reloc_shndx)
+ {
+ gold_assert(reloc_shndx < this->shnum());
+ return (*this->map_to_relocatable_relocs_)[reloc_shndx];
+ }
+
+ // Layout sections whose layout was deferred while waiting for
+ // input files from a plugin.
+ void
+ layout_deferred_sections(Layout* layout)
+ { this->do_layout_deferred_sections(layout); }
+
+ protected:
+ // The output section to be used for each input section, indexed by
+ // the input section number. The output section is NULL if the
+ // input section is to be discarded.
+ typedef std::vector<Output_section*> Output_sections;
+
+ // Read the relocs--implemented by child class.
+ virtual void
+ do_read_relocs(Read_relocs_data*) = 0;
+
+ // Process the relocs--implemented by child class.
+ virtual void
+ do_gc_process_relocs(const General_options&, 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;
+
+ // Return the number of local symbols--implemented by child class.
+ virtual unsigned int
+ do_local_symbol_count() const = 0;
+
+ // Count local symbols--implemented by child class.
+ virtual void
+ do_count_local_symbols(Stringpool_template<char>*,
+ Stringpool_template<char>*) = 0;
+
+ // Finalize the local symbols. Set the output symbol table indexes
+ // for the local variables, and set the offset where local symbol
+ // information will be stored.
+ virtual unsigned int
+ do_finalize_local_symbols(unsigned int, off_t, Symbol_table*) = 0;
+
+ // Set the output dynamic symbol table indexes for the local variables.
+ virtual unsigned int
+ do_set_local_dynsym_indexes(unsigned int) = 0;
+
+ // Set the offset where local dynamic symbol information will be stored.
+ virtual unsigned int
+ do_set_local_dynsym_offset(off_t) = 0;
+
+ // Relocate the input sections and write out the local
+ // symbols--implemented by child class.
+ virtual void
+ do_relocate(const General_options& options, 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.
+ Output_sections&
+ output_sections()
+ { return this->output_sections_; }
+
+ const Output_sections&
+ output_sections() const
+ { return this->output_sections_; }
+
+ // Set the size of the relocatable relocs array.
+ void
+ size_relocatable_relocs()
+ {
+ this->map_to_relocatable_relocs_ =
+ new std::vector<Relocatable_relocs*>(this->shnum());
+ }
+
+ // Record that we must wait for the output sections to be written
+ // before applying relocations.
+ void
+ set_relocs_must_follow_section_writes()
+ { this->relocs_must_follow_section_writes_ = true; }
+
+ private:
+ // Mapping from input sections to output section.
+ Output_sections output_sections_;
+ // Mapping from input section index to the information recorded for
+ // the relocations. This is only used for a relocatable link.
+ std::vector<Relocatable_relocs*>* map_to_relocatable_relocs_;
+ // Mappings for merge sections. This is managed by the code in the
+ // Merge_map class.
+ Object_merge_map* object_merge_map_;
+ // Whether we need to wait for output sections to be written before
+ // we can apply relocations.
+ bool relocs_must_follow_section_writes_;
+ // Used to store the relocs data computed by the Read_relocs pass.
+ // Used during garbage collection of unused sections.
+ Read_relocs_data* rd_;
+ // Used to store the symbols data computed by the Read_symbols pass.
+ // Again used during garbage collection when laying out referenced
+ // sections.
+ gold::Symbols_data *sd_;
+};
+
+// This class is used to handle relocations against a section symbol
+// in an SHF_MERGE section. For such a symbol, we need to know the
+// addend of the relocation before we can determine the final value.
+// The addend gives us the location in the input section, and we can
+// determine how it is mapped to the output section. For a
+// non-section symbol, we apply the addend to the final value of the
+// symbol; that is done in finalize_local_symbols, and does not use
+// this class.
+
+template<int size>
+class Merged_symbol_value
+{
+ public:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
+
+ // We use a hash table to map offsets in the input section to output
+ // addresses.
+ typedef Unordered_map<section_offset_type, Value> Output_addresses;
+
+ Merged_symbol_value(Value input_value, Value output_start_address)
+ : input_value_(input_value), output_start_address_(output_start_address),
+ output_addresses_()
+ { }
+
+ // Initialize the hash table.
+ void
+ initialize_input_to_output_map(const Relobj*, unsigned int input_shndx);
+
+ // Release the hash table to save space.
+ void
+ free_input_to_output_map()
+ { this->output_addresses_.clear(); }
+
+ // Get the output value corresponding to an addend. The object and
+ // input section index are passed in because the caller will have
+ // them; otherwise we could store them here.
+ Value
+ value(const Relobj* object, unsigned int input_shndx, Value addend) const
+ {
+ // This is a relocation against a section symbol. ADDEND is the
+ // offset in the section. The result should be the start of some
+ // merge area. If the object file wants something else, it should
+ // use a regular symbol rather than a section symbol.
+ // Unfortunately, PR 6658 shows a case in which the object file
+ // refers to the section symbol, but uses a negative ADDEND to
+ // compensate for a PC relative reloc. We can't handle the
+ // general case. However, we can handle the special case of a
+ // negative addend, by assuming that it refers to the start of the
+ // section. Of course, that means that we have to guess when
+ // ADDEND is negative. It is normal to see a 32-bit value here
+ // even when the template parameter size is 64, as 64-bit object
+ // file formats have 32-bit relocations. We know this is a merge
+ // section, so we know it has to fit into memory. So we assume
+ // that we won't see a value larger than a large 32-bit unsigned
+ // value. This will break objects with very very large merge
+ // sections; they probably break in other ways anyhow.
+ Value input_offset = this->input_value_;
+ if (addend < 0xffffff00)
+ {
+ input_offset += addend;
+ addend = 0;
+ }
+ typename Output_addresses::const_iterator p =
+ this->output_addresses_.find(input_offset);
+ if (p != this->output_addresses_.end())
+ return p->second + addend;
+
+ return (this->value_from_output_section(object, input_shndx, input_offset)
+ + addend);
+ }
+
+ private:
+ // Get the output value for an input offset if we couldn't find it
+ // in the hash table.
+ Value
+ value_from_output_section(const Relobj*, unsigned int input_shndx,
+ Value input_offset) const;
+
+ // The value of the section symbol in the input file. This is
+ // normally zero, but could in principle be something else.
+ Value input_value_;
+ // The start address of this merged section in the output file.
+ Value output_start_address_;
+ // A hash table which maps offsets in the input section to output
+ // addresses. This only maps specific offsets, not all offsets.
+ Output_addresses output_addresses_;
+};
+
+// This POD class is holds the value of a symbol. This is used for
+// local symbols, and for all symbols during relocation processing.
+// For special sections, such as SHF_MERGE sections, this calls a
+// function to get the final symbol value.
+
+template<int size>
+class Symbol_value
+{
+ public:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Value;
+
+ Symbol_value()
+ : output_symtab_index_(0), output_dynsym_index_(-1U), input_shndx_(0),
+ is_ordinary_shndx_(false), is_section_symbol_(false),
+ is_tls_symbol_(false), has_output_value_(true)
+ { this->u_.value = 0; }
+
+ // Get the value of this symbol. OBJECT is the object in which this
+ // symbol is defined, and ADDEND is an addend to add to the value.
+ template<bool big_endian>
+ Value
+ value(const Sized_relobj<size, big_endian>* object, Value addend) const
+ {
+ if (this->has_output_value_)
+ return this->u_.value + addend;
+ else
+ {
+ gold_assert(this->is_ordinary_shndx_);
+ return this->u_.merged_symbol_value->value(object, this->input_shndx_,
+ addend);
+ }
+ }
+
+ // Set the value of this symbol in the output symbol table.
+ void
+ set_output_value(Value value)
+ { this->u_.value = value; }
+
+ // For a section symbol in a merged section, we need more
+ // information.
+ void
+ set_merged_symbol_value(Merged_symbol_value<size>* msv)
+ {
+ gold_assert(this->is_section_symbol_);
+ this->has_output_value_ = false;
+ this->u_.merged_symbol_value = msv;
+ }
+
+ // Initialize the input to output map for a section symbol in a
+ // merged section. We also initialize the value of a non-section
+ // symbol in a merged section.
+ void
+ initialize_input_to_output_map(const Relobj* object)
+ {
+ if (!this->has_output_value_)
+ {
+ gold_assert(this->is_section_symbol_ && this->is_ordinary_shndx_);
+ Merged_symbol_value<size>* msv = this->u_.merged_symbol_value;
+ msv->initialize_input_to_output_map(object, this->input_shndx_);
+ }
+ }
+
+ // Free the input to output map for a section symbol in a merged
+ // section.
+ void
+ free_input_to_output_map()
+ {
+ if (!this->has_output_value_)
+ this->u_.merged_symbol_value->free_input_to_output_map();
+ }
+
+ // Set the value of the symbol from the input file. This is only
+ // called by count_local_symbols, to communicate the value to
+ // finalize_local_symbols.
+ void
+ set_input_value(Value value)
+ { this->u_.value = value; }
+
+ // Return the input value. This is only called by
+ // finalize_local_symbols and (in special cases) relocate_section.
+ Value
+ input_value() const
+ { return this->u_.value; }
+
+ // Return whether this symbol should go into the output symbol
+ // table.
+ bool
+ needs_output_symtab_entry() const
+ { return this->output_symtab_index_ != -1U; }
+
+ // Return the index in the output symbol table.
+ unsigned int
+ output_symtab_index() const
+ {
+ gold_assert(this->output_symtab_index_ != 0);
+ return this->output_symtab_index_;
+ }
+
+ // Set the index in the output symbol table.
+ void
+ set_output_symtab_index(unsigned int i)
+ {
+ gold_assert(this->output_symtab_index_ == 0);
+ this->output_symtab_index_ = i;
+ }
+
+ // Record that this symbol should not go into the output symbol
+ // table.
+ void
+ set_no_output_symtab_entry()
+ {
+ gold_assert(this->output_symtab_index_ == 0);
+ this->output_symtab_index_ = -1U;
+ }
+
+ // Set the index in the output dynamic symbol table.
+ void
+ set_needs_output_dynsym_entry()
+ {
+ gold_assert(!this->is_section_symbol());
+ this->output_dynsym_index_ = 0;
+ }
+
+ // Return whether this symbol should go into the output symbol
+ // table.
+ bool
+ needs_output_dynsym_entry() const
+ {
+ return this->output_dynsym_index_ != -1U;
+ }
+
+ // Record that this symbol should go into the dynamic symbol table.
+ void
+ set_output_dynsym_index(unsigned int i)
+ {
+ gold_assert(this->output_dynsym_index_ == 0);
+ this->output_dynsym_index_ = i;
+ }
+
+ // Return the index in the output dynamic symbol table.
+ unsigned int
+ output_dynsym_index() const
+ {
+ gold_assert(this->output_dynsym_index_ != 0
+ && 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_; }
+
+ 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_ : 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.
+ 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<size>* merged_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<Symbol*> vec_;
+};
+
+// A regular object file. This is size and endian specific.
+
+template<int size, bool big_endian>
+class Sized_relobj : public Relobj
+{
+ public:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef std::vector<Symbol*> Symbols;
+ typedef std::vector<Symbol_value<size> > Local_values;
+
+ static const Address invalid_address = static_cast<Address>(0) - 1;
+
+ Sized_relobj(const std::string& name, Input_file* input_file, off_t offset,
+ const typename elfcpp::Ehdr<size, big_endian>&);
+
+ ~Sized_relobj();
+
+ // 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()
+ { 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.
+ Symbol*
+ global_symbol(unsigned int sym) const
+ {
+ if (sym >= this->local_symbol_count_)
+ {
+ gold_assert(sym - this->local_symbol_count_ < this->symbols_.size());
+ return this->symbols_[sym - this->local_symbol_count_];
+ }
+ return NULL;
+ }
+
+ // Return the section index of symbol SYM. Set *VALUE to its value
+ // in the object file. Set *IS_ORDINARY if this is an ordinary
+ // section index, not a special code between SHN_LORESERVE and
+ // SHN_HIRESERVE. Note that for a symbol which is not defined in
+ // this object file, this will set *VALUE to 0 and return SHN_UNDEF;
+ // it will not return the final value of the symbol in the link.
+ unsigned int
+ symbol_section_and_value(unsigned int sym, Address* value, bool* is_ordinary);
+
+ // Return a pointer to the Symbol_value structure which holds the
+ // value of a local symbol.
+ const Symbol_value<size>*
+ local_symbol(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return &this->local_values_[sym];
+ }
+
+ // Return the index of local symbol SYM in the ordinary symbol
+ // table. A value of -1U means that the symbol is not being output.
+ unsigned int
+ symtab_index(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return this->local_values_[sym].output_symtab_index();
+ }
+
+ // Return the index of local symbol SYM in the dynamic symbol
+ // table. A value of -1U means that the symbol is not being output.
+ unsigned int
+ dynsym_index(unsigned int sym) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return this->local_values_[sym].output_dynsym_index();
+ }
+
+ // Return the input section index of local symbol SYM.
+ unsigned int
+ local_symbol_input_shndx(unsigned int sym, bool* is_ordinary) const
+ {
+ gold_assert(sym < this->local_values_.size());
+ return this->local_values_[sym].input_shndx(is_ordinary);
+ }
+
+ // Record that local symbol SYM needs a dynamic symbol entry.
+ void
+ set_needs_output_dynsym_entry(unsigned int sym)
+ {
+ gold_assert(sym < this->local_values_.size());
+ this->local_values_[sym].set_needs_output_dynsym_entry();
+ }
+
+ // Return whether the local symbol SYMNDX has a GOT offset.
+ // For TLS symbols, the GOT entry will hold its tp-relative offset.
+ bool
+ local_has_got_offset(unsigned int symndx, unsigned int got_type) const
+ {
+ Local_got_offsets::const_iterator p =
+ this->local_got_offsets_.find(symndx);
+ return (p != this->local_got_offsets_.end()
+ && p->second->get_offset(got_type) != -1U);
+ }
+
+ // Return the GOT offset of the local symbol SYMNDX.
+ unsigned int
+ local_got_offset(unsigned int symndx, unsigned int got_type) const
+ {
+ Local_got_offsets::const_iterator p =
+ this->local_got_offsets_.find(symndx);
+ gold_assert(p != this->local_got_offsets_.end());
+ unsigned int off = p->second->get_offset(got_type);
+ gold_assert(off != -1U);
+ return off;
+ }
+
+ // Set the GOT offset of the local symbol SYMNDX to GOT_OFFSET.
+ void
+ set_local_got_offset(unsigned int symndx, unsigned int got_type,
+ unsigned int got_offset)
+ {
+ Local_got_offsets::const_iterator p =
+ this->local_got_offsets_.find(symndx);
+ if (p != this->local_got_offsets_.end())
+ p->second->set_offset(got_type, got_offset);
+ else
+ {
+ Got_offset_list* g = new Got_offset_list(got_type, got_offset);
+ std::pair<Local_got_offsets::iterator, bool> ins =
+ this->local_got_offsets_.insert(std::make_pair(symndx, g));
+ gold_assert(ins.second);
+ }
+ }
+
+ // 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.
+ bool
+ get_symbol_location_info(unsigned int shndx, off_t offset,
+ Symbol_location_info* info);
+
+ // Look for a kept section corresponding to the given discarded section,
+ // and return its output address. This is used only for relocations in
+ // debugging sections.
+ Address
+ map_to_kept_section(unsigned int shndx, bool* found) const;
+
+ // 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*);
+
+ // Return the number of local symbols.
+ unsigned int
+ do_local_symbol_count() const
+ { return this->local_symbol_count_; }
+
+ // Lay out the input sections.
+ void
+ do_layout(Symbol_table*, Layout*, Read_symbols_data*);
+
+ // Layout sections whose layout was deferred while waiting for
+ // input files from a plugin.
+ void
+ do_layout_deferred_sections(Layout*);
+
+ // Add the symbols to the symbol table.
+ void
+ do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
+
+ // 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(const General_options&, 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*);
+
+ // Count the local symbols.
+ void
+ do_count_local_symbols(Stringpool_template<char>*,
+ Stringpool_template<char>*);
+
+ // Finalize the local symbols.
+ unsigned int
+ do_finalize_local_symbols(unsigned int, off_t, Symbol_table*);
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ do_set_local_dynsym_indexes(unsigned int);
+
+ // Set the offset where local dynamic symbol information will be stored.
+ unsigned int
+ do_set_local_dynsym_offset(off_t);
+
+ // Relocate the input sections and write out the local symbols.
+ void
+ do_relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout*, Output_file* of);
+
+ // Get the size of a section.
+ uint64_t
+ do_section_size(unsigned int shndx)
+ { return this->elf_file_.section_size(shndx); }
+
+ // Get the name of a section.
+ std::string
+ do_section_name(unsigned int shndx)
+ { return this->elf_file_.section_name(shndx); }
+
+ // Return the location of the contents of a section.
+ Object::Location
+ do_section_contents(unsigned int shndx)
+ { return this->elf_file_.section_contents(shndx); }
+
+ // Return section flags.
+ uint64_t
+ do_section_flags(unsigned int shndx);
+
+ // Return section entsize.
+ uint64_t
+ do_section_entsize(unsigned int shndx);
+
+ // Return section address.
+ uint64_t
+ do_section_address(unsigned int shndx)
+ { return this->elf_file_.section_addr(shndx); }
+
+ // Return section type.
+ unsigned int
+ do_section_type(unsigned int shndx)
+ { return this->elf_file_.section_type(shndx); }
+
+ // Return the section link field.
+ unsigned int
+ do_section_link(unsigned int shndx)
+ { return this->elf_file_.section_link(shndx); }
+
+ // Return the section info field.
+ unsigned int
+ do_section_info(unsigned int shndx)
+ { return this->elf_file_.section_info(shndx); }
+
+ // Return the section alignment.
+ uint64_t
+ do_section_addralign(unsigned int shndx)
+ { return this->elf_file_.section_addralign(shndx); }
+
+ // Return the Xindex structure to use.
+ Xindex*
+ do_initialize_xindex();
+
+ // Get symbol counts.
+ void
+ do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
+
+ // Get the 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<Address, uint64_t>(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<size, big_endian, Object>*
+ elf_file()
+ { return &this->elf_file_; }
+
+ // Allow a child class to access the local values.
+ Local_values*
+ local_values()
+ { return &this->local_values_; }
+
+ private:
+ // For convenience.
+ typedef Sized_relobj<size, big_endian> This;
+ static const int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
+ static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
+ static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ typedef elfcpp::Shdr<size, big_endian> Shdr;
+
+ // To keep track of discarded comdat sections, we need to map a member
+ // section index to the object and section index of the corresponding
+ // kept section.
+ struct Kept_comdat_section
+ {
+ Kept_comdat_section(Relobj* a_object, unsigned int a_shndx)
+ : object(a_object), shndx(a_shndx)
+ { }
+ Relobj* object;
+ unsigned int shndx;
+ };
+ typedef std::map<unsigned int, Kept_comdat_section>
+ Kept_comdat_section_table;
+
+ // Find the SHT_SYMTAB section, given the section headers.
+ void
+ find_symtab(const unsigned char* pshdrs);
+
+ // Return whether SHDR has the right flags for a GNU style exception
+ // frame section.
+ bool
+ check_eh_frame_flags(const elfcpp::Shdr<size, big_endian>* shdr) const;
+
+ // Return whether there is a section named .eh_frame which might be
+ // a GNU style exception frame section.
+ bool
+ find_eh_frame(const unsigned char* pshdrs, const char* names,
+ section_size_type names_size) const;
+
+ // Whether to include a section group in the link.
+ bool
+ include_section_group(Symbol_table*, Layout*, unsigned int, const char*,
+ const unsigned char*, const char *, section_size_type,
+ std::vector<bool>*);
+
+ // Whether to include a linkonce section in the link.
+ bool
+ include_linkonce_section(Layout*, unsigned int, const char*,
+ const elfcpp::Shdr<size, big_endian>&);
+
+ // Layout an input section.
+ void
+ layout_section(Layout* layout, unsigned int shndx, const char* name,
+ typename This::Shdr& shdr, unsigned int reloc_shndx,
+ unsigned int reloc_type);
+
+ // Views and sizes when relocating.
+ struct View_size
+ {
+ unsigned char* view;
+ typename elfcpp::Elf_types<size>::Elf_Addr address;
+ off_t offset;
+ section_size_type view_size;
+ bool is_input_output_view;
+ bool is_postprocessing_view;
+ };
+
+ typedef std::vector<View_size> Views;
+
+ // Write section data to the output file. Record the views and
+ // sizes in VIEWS for use when relocating.
+ void
+ write_sections(const unsigned char* pshdrs, Output_file*, Views*);
+
+ // Relocate the sections in the output file.
+ void
+ relocate_sections(const General_options& options, const Symbol_table*,
+ const Layout*, const unsigned char* pshdrs, Views*);
+
+ // Scan the input relocations for --emit-relocs.
+ void
+ emit_relocs_scan(const General_options&, Symbol_table*, Layout*,
+ const unsigned char* plocal_syms,
+ const Read_relocs_data::Relocs_list::iterator&);
+
+ // Scan the input relocations for --emit-relocs, templatized on the
+ // type of the relocation section.
+ template<int sh_type>
+ void
+ emit_relocs_scan_reltype(const General_options&, Symbol_table*, Layout*,
+ const unsigned char* plocal_syms,
+ const Read_relocs_data::Relocs_list::iterator&,
+ Relocatable_relocs*);
+
+ // Emit the relocs for --emit-relocs.
+ void
+ emit_relocs(const Relocate_info<size, big_endian>*, unsigned int,
+ unsigned int sh_type, const unsigned char* prelocs,
+ 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);
+
+ // Emit the relocs for --emit-relocs, templatized on the type of the
+ // relocation section.
+ template<int sh_type>
+ void
+ emit_relocs_reltype(const Relocate_info<size, big_endian>*, unsigned int,
+ const unsigned char* prelocs, 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);
+
+ // A type shared by split_stack_adjust_reltype and find_functions.
+ typedef std::map<section_offset_type, section_size_type> Function_offsets;
+
+ // Check for -fsplit-stack routines calling non-split-stack routines.
+ void
+ split_stack_adjust(const Symbol_table*, const unsigned char* pshdrs,
+ unsigned int sh_type, unsigned int shndx,
+ const unsigned char* prelocs, size_t reloc_count,
+ unsigned char* view, section_size_type view_size,
+ Reloc_symbol_changes** reloc_map);
+
+ template<int sh_type>
+ void
+ split_stack_adjust_reltype(const Symbol_table*, const unsigned char* pshdrs,
+ unsigned int shndx, const unsigned char* prelocs,
+ size_t reloc_count, unsigned char* view,
+ section_size_type view_size,
+ Reloc_symbol_changes** reloc_map);
+
+ // Find all functions in a section.
+ void
+ find_functions(const unsigned char* pshdrs, unsigned int shndx,
+ Function_offsets*);
+
+ // Write out the local symbols.
+ void
+ write_local_symbols(Output_file*,
+ const Stringpool_template<char>*,
+ const Stringpool_template<char>*,
+ Output_symtab_xindex*,
+ Output_symtab_xindex*);
+
+ // Clear the local symbol information.
+ void
+ clear_local_symbols()
+ {
+ this->local_values_.clear();
+ this->local_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<unsigned int, Got_offset_list*> Local_got_offsets;
+
+ // The TLS GOT offsets of local symbols. The map stores the offsets
+ // for either a single GOT entry that holds the module index of a TLS
+ // symbol, or a pair of GOT entries containing the module index and
+ // dtv-relative offset.
+ struct Tls_got_entry
+ {
+ Tls_got_entry(int got_offset, bool have_pair)
+ : got_offset_(got_offset),
+ have_pair_(have_pair)
+ { }
+ int got_offset_;
+ bool have_pair_;
+ };
+ typedef Unordered_map<unsigned int, Tls_got_entry> Local_tls_got_offsets;
+
+ // Saved information for sections whose layout was deferred.
+ struct Deferred_layout
+ {
+ static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
+ Deferred_layout(unsigned int shndx, const char* name,
+ const unsigned char* pshdr,
+ unsigned int reloc_shndx, unsigned int reloc_type)
+ : shndx_(shndx), name_(name), reloc_shndx_(reloc_shndx),
+ reloc_type_(reloc_type)
+ {
+ memcpy(this->shdr_data_, pshdr, shdr_size);
+ }
+ unsigned int shndx_;
+ std::string name_;
+ unsigned int reloc_shndx_;
+ unsigned int reloc_type_;
+ unsigned char shdr_data_[shdr_size];
+ };
+
+ // General access to the ELF file.
+ elfcpp::Elf_file<size, big_endian, Object> elf_file_;
+ // Index of SHT_SYMTAB section.
+ unsigned int symtab_shndx_;
+ // The number of local symbols.
+ unsigned int local_symbol_count_;
+ // The number of local symbols which go into the output file.
+ unsigned int output_local_symbol_count_;
+ // The number of local symbols which go into the output file's dynamic
+ // symbol table.
+ unsigned int output_local_dynsym_count_;
+ // The entries in the symbol table for the external symbols.
+ Symbols symbols_;
+ // Number of symbols defined in object file itself.
+ size_t defined_count_;
+ // File offset for local symbols.
+ off_t local_symbol_offset_;
+ // File offset for local dynamic symbols.
+ off_t local_dynsym_offset_;
+ // Values of local symbols.
+ Local_values local_values_;
+ // GOT offsets for local non-TLS symbols, and tp-relative offsets
+ // for TLS symbols, indexed by symbol number.
+ Local_got_offsets local_got_offsets_;
+ // For each input section, the offset of the input section in its
+ // output section. This is INVALID_ADDRESS if the input section requires a
+ // special mapping.
+ std::vector<Address> section_offsets_;
+ // Table mapping discarded comdat sections to corresponding kept sections.
+ Kept_comdat_section_table kept_comdat_sections_;
+ // Whether this object has a GNU style .eh_frame section.
+ bool has_eh_frame_;
+ // If this object has a GNU style .eh_frame section that is discarded in
+ // output, record the index here. Otherwise it is -1U.
+ unsigned int discarded_eh_frame_shndx_;
+ // The list of sections whose layout was deferred.
+ std::vector<Deferred_layout> deferred_layout_;
+};
+
+// A class to manage the list of all objects.
+
+class Input_objects
+{
+ public:
+ Input_objects()
+ : relobj_list_(), dynobj_list_(), sonames_(), cref_(NULL)
+ { }
+
+ // The type of the list of input relocateable objects.
+ typedef std::vector<Relobj*> Relobj_list;
+ typedef Relobj_list::const_iterator Relobj_iterator;
+
+ // The type of the list of input dynamic objects.
+ typedef std::vector<Dynobj*> Dynobj_list;
+ typedef Dynobj_list::const_iterator Dynobj_iterator;
+
+ // Add an object to the list. Return true if all is well, or false
+ // if this object should be ignored.
+ bool
+ add_object(Object*);
+
+ // Start processing an archive.
+ void
+ archive_start(Archive*);
+
+ // Stop processing an archive.
+ void
+ archive_stop(Archive*);
+
+ // For each dynamic object, check whether we've seen all of its
+ // explicit dependencies.
+ void
+ check_dynamic_dependencies() const;
+
+ // Return whether an object was found in the system library
+ // directory.
+ bool
+ found_in_system_library_directory(const Object*) const;
+
+ // Print symbol counts.
+ void
+ print_symbol_counts(const Symbol_table*) const;
+
+ // Iterate over all regular objects.
+
+ Relobj_iterator
+ relobj_begin() const
+ { return this->relobj_list_.begin(); }
+
+ Relobj_iterator
+ relobj_end() const
+ { return this->relobj_list_.end(); }
+
+ // Iterate over all dynamic objects.
+
+ Dynobj_iterator
+ dynobj_begin() const
+ { return this->dynobj_list_.begin(); }
+
+ Dynobj_iterator
+ dynobj_end() const
+ { return this->dynobj_list_.end(); }
+
+ // Return whether we have seen any dynamic objects.
+ bool
+ any_dynamic() const
+ { return !this->dynobj_list_.empty(); }
+
+ // Return the number of input objects.
+ int
+ number_of_input_objects() const
+ { return this->relobj_list_.size() + this->dynobj_list_.size(); }
+
+ private:
+ Input_objects(const Input_objects&);
+ Input_objects& operator=(const Input_objects&);
+
+ // The list of ordinary objects included in the link.
+ Relobj_list relobj_list_;
+ // The list of dynamic objects included in the link.
+ Dynobj_list dynobj_list_;
+ // SONAMEs that we have seen.
+ Unordered_set<std::string> sonames_;
+ // Manage cross-references if requested.
+ Cref* cref_;
+};
+
+// Some of the information we pass to the relocation routines. We
+// group this together to avoid passing a dozen different arguments.
+
+template<int size, bool big_endian>
+struct Relocate_info
+{
+ // Command line options.
+ const General_options* options;
+ // Symbol table.
+ const Symbol_table* symtab;
+ // Layout.
+ const Layout* layout;
+ // Object being relocated.
+ Sized_relobj<size, big_endian>* object;
+ // Section index of relocation section.
+ unsigned int reloc_shndx;
+ // Section header of relocation section.
+ const unsigned char* reloc_shdr;
+ // Section index of section being relocated.
+ unsigned int data_shndx;
+ // Section header of data section.
+ const unsigned char* data_shdr;
+
+ // Return a string showing the location of a relocation. This is
+ // only used for error messages.
+ std::string
+ location(size_t relnum, off_t reloffset) const;
+};
+
+// Return whether INPUT_FILE contains an ELF object start at file
+// offset OFFSET. This sets *START to point to a view of the start of
+// the file. It sets *READ_SIZE to the number of bytes in the view.
+
+extern bool
+is_elf_object(Input_file* input_file, off_t offset,
+ const unsigned char** start, int *read_size);
+
+// Return an Object appropriate for the input file. P is BYTES long,
+// and holds the ELF header. If PUNCONFIGURED is not NULL, then if
+// this sees an object the linker is not configured to support, it
+// sets *PUNCONFIGURED to true and returns NULL without giving an
+// error message.
+
+extern Object*
+make_elf_object(const std::string& name, Input_file*,
+ off_t offset, const unsigned char* p,
+ section_offset_type bytes, bool* punconfigured);
+
+} // end namespace gold
+
+#endif // !defined(GOLD_OBJECT_H)
projects / msp430-binutils.git / blobdiff