#ifndef GOLD_OBJECT_H
#define GOLD_OBJECT_H
-#include <cassert>
+#include <string>
#include <vector>
#include "elfcpp.h"
+#include "elfcpp_file.h"
#include "fileread.h"
#include "target.h"
-#include "symtab.h"
namespace gold
{
-class Output_section;
+class General_options;
+class Stringpool;
class Layout;
+class Output_section;
+class Output_file;
+class Dynobj;
// 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.
+ off_t section_names_size;
// Symbol data.
File_view* symbols;
// Size of symbol data in bytes.
File_view* symbol_names;
// Size of symbol name data in bytes.
off_t symbol_names_size;
+
+ // Version information. This is only used on dynamic objects.
+ // Version symbol data (from SHT_GNU_versym section).
+ File_view* versym;
+ off_t versym_size;
+ // Version definition data (from SHT_GNU_verdef section).
+ File_view* verdef;
+ off_t verdef_size;
+ unsigned int verdef_info;
+ // Needed version data (from SHT_GNU_verneed section).
+ File_view* verneed;
+ off_t verneed_size;
+ unsigned int verneed_info;
+};
+
+// 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;
};
-// Object is an interface 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). The actual instantiations are
-// Sized_object<32> and Sized_object<64>
+// 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;
+};
+
+// 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
{
// 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_(0), is_dynamic_(is_dynamic), target_(NULL),
- map_to_output_()
+ : name_(name), input_file_(input_file), offset_(offset), shnum_(-1U),
+ is_dynamic_(is_dynamic), target_(NULL)
{ }
virtual ~Object()
// appropriate checked type.
template<int size, bool big_endian>
Sized_target<size, big_endian>*
- sized_target();
+ sized_target(ACCEPT_SIZE_ENDIAN_ONLY);
- // Read the symbol and relocation information.
- Read_symbols_data
- read_symbols()
- { return this->do_read_symbols(); }
+ // Get the number of sections.
+ unsigned int
+ shnum() const
+ { return this->shnum_; }
- // Add symbol information to the global symbol table.
+ // Return a view of the contents of a section. Set *PLEN to the
+ // size.
+ const unsigned char*
+ section_contents(unsigned int shndx, off_t* plen);
+
+ // Return the name of a section given a section index. This is only
+ // used for error messages.
+ 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); }
+
+ // Read the symbol information.
void
- add_symbols(Symbol_table* symtab, Read_symbols_data rd)
- { this->do_add_symbols(symtab, rd); }
+ 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(Layout* lay)
- { this->do_layout(lay); }
+ layout(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Read_symbols_data* sd)
+ { this->do_layout(options, symtab, layout, sd); }
- 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
+ // Add symbol information to the global symbol table.
+ void
+ add_symbols(Symbol_table* symtab, Read_symbols_data* sd)
+ { this->do_add_symbols(symtab, sd); }
+
+ // 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
{
- // The output section. This is NULL if the input section is to be
- // discarded.
- Output_section* output_section;
- // The offset within the output section.
- off_t offset;
+ 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, off_t data_size)
+ { return View(this->get_view(file_offset, data_size)); }
+
+ // Report an error.
+ void
+ error(const char* format, ...) ATTRIBUTE_PRINTF_2;
+
+ // A location in the file.
+ struct Location
+ {
+ off_t file_offset;
+ off_t data_size;
+
+ Location(off_t fo, off_t 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)); }
+
+ protected:
// Read the symbols--implemented by child class.
- virtual Read_symbols_data
- do_read_symbols() = 0;
+ virtual void
+ do_read_symbols(Read_symbols_data*) = 0;
+
+ // Lay out sections--implemented by child class.
+ virtual void
+ do_layout(const General_options&, 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) = 0;
+ do_add_symbols(Symbol_table*, Read_symbols_data*) = 0;
- // Lay out sections--implemented by child class.
- virtual void
- do_layout(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 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 the file.
Input_file*
// Get a view into the underlying file.
const unsigned char*
- get_view(off_t start, off_t size);
+ get_view(off_t start, off_t size)
+ { return this->input_file_->file().get_view(start + this->offset_, size); }
- // Get the number of sections.
- unsigned int
- shnum(void) const
- { return this->shnum_; }
+ // Get a lasting view into the underlying file.
+ File_view*
+ get_lasting_view(off_t start, off_t size)
+ {
+ return this->input_file_->file().get_lasting_view(start + this->offset_,
+ size);
+ }
- // Set the number of sections.
+ // Read data from the underlying file.
void
- set_shnum(int shnum)
- { this->shnum_ = shnum; }
+ read(off_t start, off_t size, void* p)
+ { this->input_file_->file().read(start + this->offset_, size, p); }
// Set the target.
void
- set_target(Target* target)
- { this->target_ = target; }
+ set_target(int machine, int size, bool big_endian, int osabi,
+ int abiversion);
- // Read data from the underlying file.
+ // Set the number of sections.
void
- read(off_t start, off_t size, void* p);
+ set_shnum(int shnum)
+ { this->shnum_ = shnum; }
- // Get a lasting view into the underlying file.
- File_view*
- get_lasting_view(off_t start, off_t size);
+ // Functions used by both Sized_relobj and Sized_dynobj.
- // Return the vector mapping input sections to output sections.
- std::vector<Map_to_output>&
- map_to_output()
- { return this->map_to_output_; }
+ // 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*);
+
+ // 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*);
private:
// This class may not be copied.
Object(const Object&);
Object& operator=(const Object&);
- // Name of object as printed to use.
+ // Name of object as printed to user.
std::string name_;
// For reading the file.
Input_file* input_file_;
bool is_dynamic_;
// Target functions--may be NULL if the target is not known.
Target* target_;
- // Mapping from input sections to output section.
- std::vector<Map_to_output> map_to_output_;
};
// Implement sized_target inline for efficiency. This approach breaks
template<int size, bool big_endian>
inline Sized_target<size, big_endian>*
-Object::sized_target()
+Object::sized_target(ACCEPT_SIZE_ENDIAN_ONLY)
{
- assert(this->target_->get_size() == size);
- assert(this->target_->is_big_endian() ? big_endian : !big_endian);
+ gold_assert(this->target_->get_size() == size);
+ gold_assert(this->target_->is_big_endian() ? big_endian : !big_endian);
return static_cast<Sized_target<size, big_endian>*>(this->target_);
}
+// A regular object (ET_REL). This is an abstract base class itself.
+// The implementations 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)
+ { }
+
+ // Read the relocs.
+ void
+ read_relocs(Read_relocs_data* rd)
+ { return this->do_read_relocs(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); }
+
+ // Initial local symbol processing: set the offset where local
+ // symbol information will be stored; add local symbol names to
+ // *POOL; return the new local symbol index.
+ unsigned int
+ finalize_local_symbols(unsigned int index, off_t off, Stringpool* pool)
+ { return this->do_finalize_local_symbols(index, off, pool); }
+
+ // 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->map_to_output_.size());
+ return this->map_to_output_[shndx].output_section != NULL;
+ }
+
+ // 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.
+ inline Output_section*
+ output_section(unsigned int shndx, off_t* poff);
+
+ // Set the offset of an input section within its output section.
+ void
+ set_section_offset(unsigned int shndx, off_t off)
+ {
+ gold_assert(shndx < this->map_to_output_.size());
+ this->map_to_output_[shndx].offset = off;
+ }
+
+ 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.
+ off_t offset;
+ };
+
+ // Read the relocs--implemented by child class.
+ virtual void
+ do_read_relocs(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;
+
+ // Finalize local symbols--implemented by child class.
+ virtual unsigned int
+ do_finalize_local_symbols(unsigned int, off_t, Stringpool*) = 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;
+
+ // Return the vector mapping input sections to output sections.
+ std::vector<Map_to_output>&
+ map_to_output()
+ { return this->map_to_output_; }
+
+ private:
+ // Mapping from input sections to output section.
+ std::vector<Map_to_output> map_to_output_;
+};
+
+// Implement Object::output_section inline for efficiency.
+inline Output_section*
+Relobj::output_section(unsigned int shndx, off_t* poff)
+{
+ 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;
+}
+
// A regular object file. This is size and endian specific.
template<int size, bool big_endian>
-class Sized_object : public Object
+class Sized_relobj : public Relobj
{
public:
- Sized_object(const std::string& name, Input_file* input_file, off_t offset,
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef std::vector<Address> Local_values;
+
+ Sized_relobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>&);
- ~Sized_object();
+ ~Sized_relobj();
// Set up the object file based on the ELF header.
void
setup(const typename elfcpp::Ehdr<size, big_endian>&);
+ // 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_indexes_.size());
+ gold_assert(this->local_indexes_[sym] != 0);
+ return this->local_indexes_[sym];
+ }
+
// Read the symbols.
- Read_symbols_data
- do_read_symbols();
+ void
+ do_read_symbols(Read_symbols_data*);
+
+ // Lay out the input sections.
+ void
+ do_layout(const General_options&, Symbol_table*, Layout*,
+ Read_symbols_data*);
// Add the symbols to the symbol table.
void
- do_add_symbols(Symbol_table*, Read_symbols_data);
+ do_add_symbols(Symbol_table*, Read_symbols_data*);
- // Lay out the input sections.
+ // Read the relocs.
+ void
+ do_read_relocs(Read_relocs_data*);
+
+ // Scan the relocs and adjust the symbol table.
+ void
+ do_scan_relocs(const General_options&, Symbol_table*, Layout*,
+ Read_relocs_data*);
+
+ // Finalize the local symbols.
+ unsigned int
+ do_finalize_local_symbols(unsigned int, off_t, Stringpool*);
+
+ // Relocate the input sections and write out the local symbols.
void
- do_layout(Layout*);
+ do_relocate(const General_options& options, const Symbol_table* symtab,
+ const Layout*, Output_file* of);
+
+ // 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 this->elf_file_.section_flags(shndx); }
// Return the appropriate Sized_target structure.
Sized_target<size, big_endian>*
sized_target()
- { return this->Object::sized_target<size, big_endian>(); }
+ {
+ return this->Object::sized_target
+ SELECT_SIZE_ENDIAN_NAME(size, big_endian) (
+ SELECT_SIZE_ENDIAN_ONLY(size, big_endian));
+ }
private:
- // This object may not be copied.
- Sized_object(const Sized_object&);
- Sized_object& operator=(const Sized_object&);
-
// For convenience.
- typedef Sized_object<size, big_endian> This;
+ 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;
+
+ // Find the SHT_SYMTAB section, given the section headers.
+ void
+ find_symtab(const unsigned char* pshdrs);
// Whether to include a section group in the link.
bool
include_linkonce_section(Layout*, const char*,
const elfcpp::Shdr<size, big_endian>&);
- // ELF file header e_flags field.
- unsigned int flags_;
- // File offset of section header table.
- off_t shoff_;
- // Offset of SHT_STRTAB section holding section names.
- unsigned int shstrndx_;
+ // Views and sizes when relocating.
+ struct View_size
+ {
+ unsigned char* view;
+ typename elfcpp::Elf_types<size>::Elf_Addr address;
+ off_t offset;
+ off_t view_size;
+ };
+
+ 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*);
+
+ // Write out the local symbols.
+ void
+ write_local_symbols(Output_file*, const Stringpool*);
+
+ // General access to the ELF file.
+ elfcpp::Elf_file<size, big_endian, Object> elf_file_;
// Index of SHT_SYMTAB section.
- unsigned int symtab_shnum_;
+ 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 entries in the symbol table for the external symbols.
Symbol** symbols_;
+ // File offset for local symbols.
+ off_t local_symbol_offset_;
+ // Values of local symbols.
+ Local_values local_values_;
+ // Indexes of local symbols in the output file; -1U if not present.
+ std::vector<unsigned int> local_indexes_;
+};
+
+// A class to manage the list of all objects.
+
+class Input_objects
+{
+ public:
+ Input_objects()
+ : relobj_list_(), dynobj_list_(), target_(NULL), sonames_()
+ { }
+
+ // 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*);
+
+ // Get the target we should use for the output file.
+ Target*
+ target() const
+ { return this->target_; }
+
+ // 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(); }
+
+ 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_;
+ // The target.
+ Target* target_;
+ // SONAMEs that we have seen.
+ Unordered_set<std::string> sonames_;
};
-// The type of the list of input objects.
+// Some of the information we pass to the relocation routines. We
+// group this together to avoid passing a dozen different arguments.
-typedef std::list<Object*> Object_list;
+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;
+ // Number of local symbols.
+ unsigned int local_symbol_count;
+ // Values of local symbols.
+ const typename Sized_relobj<size, big_endian>::Local_values* local_values;
+ // Global symbols.
+ const Symbol* const * symbols;
+ // Section index of relocation section.
+ unsigned int reloc_shndx;
+ // Section index of section being relocated.
+ unsigned int data_shndx;
+
+ // 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 an Object appropriate for the input file. P is BYTES long,
// and holds the ELF header.
-extern Object* make_elf_object(const std::string& name, Input_file*,
- off_t offset, const unsigned char* p,
- off_t bytes);
+extern Object*
+make_elf_object(const std::string& name, Input_file*,
+ off_t offset, const unsigned char* p,
+ off_t bytes);
} // end namespace gold