2012-03-21 Cary Coutant <ccoutant@google.com>

	* Makefile.am: Add gdb-index.cc, gdb-index.h.
	* Makefile.in: Regenerate.
	* dwarf_reader.cc (Sized_elf_reloc_mapper::do_initialize): New function.
	(Sized_elf_reloc_mapper::symbol_section): New function.
	(Sized_elf_reloc_mapper::do_get_reloc_target): New function.
	(make_elf_reloc_mapper): New function.
	(Dwarf_abbrev_table::clear_abbrev_codes): New function.
	(Dwarf_abbrev_table::do_read_abbrevs): New function.
	(Dwarf_abbrev_table::do_get_abbrev): New function.
	(Dwarf_ranges_table::read_ranges_table): New function.
	(Dwarf_ranges_table::read_range_list): New function.
	(Dwarf_pubnames_table::read_section): New function.
	(Dwarf_pubnames_table::read_header): New function.
	(Dwarf_pubnames_table::next_name): New function.
	(Dwarf_die::Dwarf_die): New function.
	(Dwarf_die::read_attributes): New function.
	(Dwarf_die::skip_attributes): New function.
	(Dwarf_die::set_name): New function.
	(Dwarf_die::set_linkage_name): New function.
	(Dwarf_die::attribute): New function.
	(Dwarf_die::string_attribute): New function.
	(Dwarf_die::int_attribute): New function.
	(Dwarf_die::uint_attribute): New function.
	(Dwarf_die::ref_attribute): New function.
	(Dwarf_die::child_offset): New function.
	(Dwarf_die::sibling_offset): New function.
	(Dwarf_info_reader::check_buffer): New function.
	(Dwarf_info_reader::parse): New function.
	(Dwarf_info_reader::do_parse): New function.
	(Dwarf_info_reader::do_read_string_table): New function.
	(Dwarf_info_reader::lookup_reloc): New function.
	(Dwarf_info_reader::get_string): New function.
	(Dwarf_info_reader::visit_compilation_unit): New function.
	(Dwarf_info_reader::visit_type_unit): New function.
	(Sized_dwarf_line_info::Sized_dwarf_line_info): Use
	Sized_elf_reloc_mapper.
	(Sized_dwarf_line_info::symbol_section): Remove function.
	(Sized_dwarf_line_info::read_relocs): Use Sized_elf_reloc_mapper.
	(Sized_dwarf_line_info::read_line_mappings): Remove object
	parameter, adjust callers.
	(Sized_dwarf_line_info::format_file_lineno): Fix type of cast.
	* dwarf_reader.h: Include <sys/types.h>.
	(class Track_relocs): Remove forward declaration.
	(class Elf_reloc_mapper): New class.
	(class Sized_elf_reloc_mapper): New class.
	(class Dwarf_abbrev_table): New class.
	(class Dwarf_range_list): New class.
	(class Dwarf_ranges_table): New class.
	(class Dwarf_pubnames_table): New class.
	(class Dwarf_die): New class.
	(class Dwarf_info_reader): New class.
	(Sized_dwarf_line_info::read_line_mappings): Remove object parameter.
	(Sized_dwarf_line_info::symbol_section): Remove member function.
	* dynobj.h (Sized_dynobj::do_section_contents): Refactor code from
	base class.
	* gdb-index.cc: New source file.
	* gdb-index.h: New source file.
	* incremental.cc (Sized_relobj_incr::do_layout): Track .debug_info
	and .debug_types sections, call Layout::add_to_gdb_index.
	(Sized_relobj_incr::do_section_name): Implement.
	(Sized_relobj_incr::do_section_contents): Adjust parameter list and
	return type; Implement.
	(Sized_incr_dynobj::do_section_contents): Adjust parameter list and
	return type.
	* incremental.h (Sized_relobj_incr::do_section_contents): Adjust
	parameter list and return type.
	(Sized_incr_dynobj::do_section_contents): Likewise.
	* layout.cc: Include gdb-index.h.
	(Layout::Layout): Initialize gdb_index_data_.
	(Layout::init_fixed_output_section): Check for .gdb_index section.
	(Layout::add_to_gdb_index): New function. Instantiate.
	* layout.h: Add forward declaration for class Gdb_index.
	(Layout::add_to_gdb_index): New member function.
	(Layout::gdb_index_data_): New data member.
	* main.cc: Include gdb-index.h.
	(main): Print statistics for gdb index.
	* object.cc (Object::section_contents): Move code into
	do_section_contents.
	(need_decompressed_section): Check for sections needed when building
	gdb index.
	(build_compressed_section_map): Likewise.
	(Sized_relobj_file::do_read_symbols): Need local symbols when building
	gdb index.
	(Sized_relobj_file::do_layout): Track .debug_info and .debug_types
	sections; call Layout::add_to_gdb_index.
	(Sized_relobj_file::do_decompressed_section_contents): Call
	do_section_contents directly.
	* object.h (Object::do_section_contents): Adjust parameter list and
	return type.
	(Object::do_decompressed_section_contents): Call do_section_contents
	directly.
	(Sized_relobj_file::do_section_contents): Adjust parameter list and
	return type.
	* options.h (class General_options): Add --gdb-index option.
	* plugin.cc (Sized_pluginobj::do_section_contents): Adjust parameter
	list and return type.
	* plugin.h (Sized_pluginobj::do_section_contents): Likewise.
	* reloc.h (Track_relocs::checkpoint): New function.
	(Track_relocs::reset): New function.

	* testsuite/Makefile.am (gdb_index_test_1.sh, gdb_index_test_2.sh):
	New test cases.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/gdb_index_test.cc: New test source file.
	* testsuite/gdb_index_test_1.sh: New test source file.
	* testsuite/gdb_index_test_2.sh: New test source file.

1 files changed, 213 insertions, 0 deletions

diff --git a/gold/gdb-index.h b/gold/gdb-index.h
new file mode 100644
index 0000000..1ca38cc
--- /dev/null
+++ b/gold/gdb-index.h
@@ -0,0 +1,213 @@
+// gdb-index.h -- generate .gdb_index section for fast debug lookup  -*- C++ -*-
+
+// Copyright 2012 Free Software Foundation, Inc.
+// Written by Cary Coutant <ccoutant@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.
+
+#include <sys/types.h>
+#include <vector>
+
+#include "gold.h"
+#include "output.h"
+#include "mapfile.h"
+#include "stringpool.h"
+
+#ifndef GOLD_GDB_INDEX_H
+#define GOLD_GDB_INDEX_H
+
+namespace gold
+{
+
+class Output_section;
+class Output_file;
+class Mapfile;
+template<int size, bool big_endian>
+class Sized_relobj;
+class Dwarf_range_list;
+template <typename T>
+class Gdb_hashtab;
+
+// This class manages the .gdb_index section, which is a fast
+// lookup table for DWARF information used by the gdb debugger.
+// The format of this section is described in gdb/doc/gdb.texinfo.
+
+class Gdb_index : public Output_section_data
+{
+ public:
+  Gdb_index(Output_section* gdb_index_section);
+
+  ~Gdb_index();
+
+  // Scan a .debug_info or .debug_types input section.
+  void scan_debug_info(bool is_type_unit,
+		       Relobj* object,
+		       const unsigned char* symbols,
+		       off_t symbols_size,
+		       unsigned int shndx,
+		       unsigned int reloc_shndx,
+		       unsigned int reloc_type);
+
+  // Add a compilation unit.
+  int
+  add_comp_unit(off_t cu_offset, off_t cu_length)
+  {
+    this->comp_units_.push_back(Comp_unit(cu_offset, cu_length));
+    return this->comp_units_.size() - 1;
+  }
+
+  // Add a type unit.
+  int
+  add_type_unit(off_t tu_offset, off_t type_offset, uint64_t signature)
+  {
+    this->type_units_.push_back(Type_unit(tu_offset, type_offset, signature));
+    return this->type_units_.size() - 1;
+  }
+
+  // Add an address range.
+  void
+  add_address_range_list(Relobj* object, unsigned int cu_index,
+			 Dwarf_range_list* ranges)
+  {
+    this->ranges_.push_back(Per_cu_range_list(object, cu_index, ranges));
+  }
+
+  // Add a symbol.
+  void
+  add_symbol(int cu_index, const char* sym_name);
+
+  // Return TRUE if we have already processed the pubnames set at
+  // OFFSET in section SHNDX
+  bool
+  pubnames_read(unsigned int shndx, off_t offset);
+
+  // Return TRUE if we have already processed the pubtypes set at
+  // OFFSET in section SHNDX
+  bool
+  pubtypes_read(unsigned int shndx, off_t offset);
+
+  // Print usage statistics.
+  static void
+  print_stats();
+
+ protected:
+  // This is called to update the section size prior to assigning
+  // the address and file offset.
+  void
+  update_data_size()
+  { this->set_final_data_size(); }
+
+  // Set the final data size.
+  void
+  set_final_data_size();
+
+  // Write the data to the file.
+  void
+  do_write(Output_file*);
+
+  // Write to a map file.
+  void
+  do_print_to_mapfile(Mapfile* mapfile) const
+  { mapfile->print_output_data(this, _("** gdb_index")); }
+
+ private:
+  // An entry in the compilation unit list.
+  struct Comp_unit
+  {
+    Comp_unit(off_t off, off_t len)
+      : cu_offset(off), cu_length(len)
+    { }
+    uint64_t cu_offset;
+    uint64_t cu_length;
+  };
+
+  // An entry in the type unit list.
+  struct Type_unit
+  {
+    Type_unit(off_t off, off_t toff, uint64_t sig)
+      : tu_offset(off), type_offset(toff), type_signature(sig)
+    { }
+    uint64_t tu_offset;
+    uint64_t type_offset;
+    uint64_t type_signature;
+  };
+
+  // An entry in the address range list.
+  struct Per_cu_range_list
+  {
+    Per_cu_range_list(Relobj* obj, uint32_t index, Dwarf_range_list* r)
+      : object(obj), cu_index(index), ranges(r)
+    { }
+    Relobj* object;
+    uint32_t cu_index;
+    Dwarf_range_list* ranges;
+  };
+
+  // A symbol table entry.
+  struct Gdb_symbol
+  {
+    Stringpool::Key name_key;
+    unsigned int hashval;
+    unsigned int cu_vector_index;
+
+    // Return the hash value.
+    unsigned int
+    hash()
+    { return this->hashval; }
+
+    // Return true if this symbol is the same as SYMBOL.
+    bool
+    equal(Gdb_symbol* symbol)
+    { return this->name_key == symbol->name_key; }
+  };
+
+  typedef std::vector<int> Cu_vector;
+
+  // The .gdb_index section.
+  Output_section* gdb_index_section_;
+  // The list of DWARF compilation units.
+  std::vector<Comp_unit> comp_units_;
+  // The list of DWARF type units.
+  std::vector<Type_unit> type_units_;
+  // The list of address ranges.
+  std::vector<Per_cu_range_list> ranges_;
+  // The symbol table.
+  Gdb_hashtab<Gdb_symbol>* gdb_symtab_;
+  // The CU vector portion of the constant pool.
+  std::vector<Cu_vector*> cu_vector_list_;
+  // An array to map from a CU vector index to an offset to the constant pool.
+  off_t* cu_vector_offsets_;
+  // The string portion of the constant pool.
+  Stringpool stringpool_;
+  // Offsets of the various pieces of the .gdb_index section.
+  off_t tu_offset_;
+  off_t addr_offset_;
+  off_t symtab_offset_;
+  off_t cu_pool_offset_;
+  off_t stringpool_offset_;
+  // Section index and offset of last read pubnames section.
+  unsigned int pubnames_shndx_;
+  off_t pubnames_offset_;
+  // Section index and offset of last read pubtypes section.
+  unsigned int pubtypes_shndx_;
+  off_t pubtypes_offset_;
+};
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_GDB_INDEX_H)