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1 | // dwarf_reader.h -- parse dwarf2/3 debug information for gold -*- C++ -*- |
2 | ||
3 | // Copyright 2007 Free Software Foundation, Inc. | |
4 | // Written by Ian Lance Taylor <iant@google.com>. | |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
23 | #ifndef GOLD_DWARF_READER_H | |
24 | #define GOLD_DWARF_READER_H | |
25 | ||
26 | #include <vector> | |
27 | ||
28 | #include "elfcpp_swap.h" | |
29 | #include "dwarf.h" | |
30 | ||
31 | namespace gold | |
32 | { | |
33 | ||
34 | struct LineStateMachine; | |
35 | ||
36 | // This class is used to read the line information from the debugging | |
37 | // section of an object file. | |
38 | ||
e43872e9 | 39 | template<int size, bool big_endian> |
5c2c6c95 ILT |
40 | class Dwarf_line_info |
41 | { | |
42 | public: | |
43 | // Initializes a .debug_line reader. Buffer and buffer length point | |
44 | // to the beginning and length of the line information to read. | |
45 | // Reader is a ByteReader class that has the endianness set | |
46 | // properly. | |
47 | Dwarf_line_info(const unsigned char* buffer, off_t buffer_length) | |
48 | : buffer_(buffer), buffer_end_(buffer + buffer_length), | |
49 | directories_(1), files_(1) | |
50 | { } | |
51 | ||
52 | // Start processing line info, and populates the offset_map_. | |
5c2c6c95 | 53 | void |
e43872e9 | 54 | read_line_mappings(); |
5c2c6c95 ILT |
55 | |
56 | // Given a section number and an offset, returns the associated | |
57 | // file and line-number, as a string: "file:lineno". If unable | |
58 | // to do the mapping, returns the empty string. You must call | |
59 | // read_line_mappings() before calling this function. | |
60 | std::string | |
61 | addr2line(unsigned int shndx, off_t offset); | |
62 | ||
63 | private: | |
64 | // Reads the DWARF2/3 header for this line info. Each takes as input | |
65 | // a starting buffer position, and returns the ending position. | |
5c2c6c95 ILT |
66 | const unsigned char* |
67 | read_header_prolog(const unsigned char* lineptr); | |
68 | ||
69 | const unsigned char* | |
70 | read_header_tables(const unsigned char* lineptr); | |
71 | ||
72 | // Reads the DWARF2/3 line information. | |
73 | const unsigned char* | |
e43872e9 | 74 | read_lines(const unsigned char* lineptr); |
5c2c6c95 ILT |
75 | |
76 | // Process a single line info opcode at START using the state | |
77 | // machine at LSM. Return true if we should define a line using the | |
78 | // current state of the line state machine. Place the length of the | |
79 | // opcode in LEN. | |
80 | bool | |
e43872e9 | 81 | process_one_opcode(const unsigned char* start, |
5c2c6c95 ILT |
82 | struct LineStateMachine* lsm, size_t* len); |
83 | ||
5c2c6c95 ILT |
84 | // A DWARF2/3 line info header. This is not the same size as in the |
85 | // actual file, as the one in the file may have a 32 bit or 64 bit | |
86 | // lengths. | |
87 | ||
88 | struct Dwarf_line_infoHeader | |
89 | { | |
90 | off_t total_length; | |
91 | int version; | |
92 | off_t prologue_length; | |
93 | int min_insn_length; // insn stands for instructin | |
94 | bool default_is_stmt; // stmt stands for statement | |
95 | signed char line_base; | |
96 | int line_range; | |
97 | unsigned char opcode_base; | |
98 | std::vector<unsigned char> std_opcode_lengths; | |
99 | int offset_size; | |
100 | } header_; | |
101 | ||
102 | // buffer is the buffer for our line info, starting at exactly where | |
103 | // the line info to read is. | |
104 | const unsigned char* buffer_; | |
105 | const unsigned char* const buffer_end_; | |
106 | ||
107 | // Holds the directories and files as we see them. | |
108 | std::vector<std::string> directories_; | |
109 | // The first part is an index into directories_, the second the filename. | |
110 | std::vector< std::pair<int, std::string> > files_; | |
111 | ||
112 | // We can't do better than to keep the offsets in a sorted vector. | |
113 | // Here, offset is the key, and file_num/line_num is the value. | |
114 | struct Offset_to_lineno_entry | |
115 | { | |
116 | off_t offset; | |
117 | int file_num; // a pointer into files_ | |
118 | int line_num; | |
119 | // Offsets are unique within a section, so that's a sufficient sort key. | |
120 | bool operator<(const Offset_to_lineno_entry& that) const | |
121 | { return this->offset < that.offset; } | |
122 | }; | |
123 | // We have a vector of offset->lineno entries for every input section. | |
124 | typedef Unordered_map<unsigned int, std::vector<Offset_to_lineno_entry> > | |
125 | Lineno_map; | |
126 | ||
127 | Lineno_map line_number_map_; | |
128 | }; | |
129 | ||
130 | } // End namespace gold. | |
131 | ||
132 | #endif // !defined(GOLD_DWARF_READER_H) |