aboutsummaryrefslogtreecommitdiff
blob: 584e0535d40e97c29476065ad87e5b82b97916be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
// gdb-index.h -- generate .gdb_index section for fast debug lookup  -*- C++ -*-

// Copyright (C) 2012-2019 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;
class Gdb_index_info_reader;
class Dwarf_pubnames_table;

// 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.  FLAGS are the gdb_index version 7 flags to be stored in
  // the high-byte of the cu_index field.
  void
  add_symbol(int cu_index, const char* sym_name, uint8_t flags);

  // Return the offset into the pubnames table for the cu at the given
  // offset.
  off_t
  find_pubname_offset(off_t cu_offset);

  // Return the offset into the pubtypes table for the cu at the
  // given offset.
  off_t
  find_pubtype_offset(off_t cu_offset);

  // Return TRUE if we have already processed the pubnames and types
  // set for OBJECT of the CUs and TUS associated with the statement
  // list at OFFSET.
  bool
  pubnames_read(const Relobj* object, off_t offset);

  // Record that we have already read the pubnames associated with
  // OBJECT and OFFSET.
  void
  set_pubnames_read(const Relobj* object, off_t offset);

  // Return a pointer to the given table.
  Dwarf_pubnames_table*
  pubnames_table()
  { return pubnames_table_; }

  Dwarf_pubnames_table*
  pubtypes_table()
  { return pubtypes_table_; }

  // 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")); }

  // Create a map from dies to pubnames.
  Dwarf_pubnames_table*
  map_pubtable_to_dies(unsigned int attr,
                       Gdb_index_info_reader* dwinfo,
                       Relobj* object,
                       const unsigned char* symbols,
                       off_t symbols_size);

  // Wrapper for map_pubtable_to_dies
  void
  map_pubnames_and_types_to_dies(Gdb_index_info_reader* dwinfo,
                                 Relobj* object,
                                 const unsigned char* symbols,
                                 off_t symbols_size);

 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<std::pair<int, uint8_t> > Cu_vector;

  typedef Unordered_map<off_t, off_t> Pubname_offset_map;
  Pubname_offset_map cu_pubname_map_;
  Pubname_offset_map cu_pubtype_map_;

  // Scan the given pubtable and build a map of the various dies it
  // refers to, so we can process the entries when we encounter the
  // die.
  void
  map_pubtable_to_dies(Dwarf_pubnames_table* table,
                       Pubname_offset_map* map);

  // Tables to store the pubnames section of the current object.
  Dwarf_pubnames_table* pubnames_table_;
  Dwarf_pubnames_table* pubtypes_table_;

  // 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_;
  // Object, stmt list offset of the CUs and TUs associated with the
  // last read pubnames and pubtypes sections.
  const Relobj* pubnames_object_;
  off_t stmt_list_offset_;
};

} // End namespace gold.

#endif // !defined(GOLD_GDB_INDEX_H)