1 /* DWARF 2 debugging format support for GDB.
3 Copyright (C) 1994-2022 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #ifndef DWARF2_LINE_HEADER_H
21 #define DWARF2_LINE_HEADER_H
25 /* dir_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 and
27 typedef int dir_index
;
29 /* file_name_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5
31 typedef int file_name_index
;
37 file_entry () = default;
39 file_entry (const char *name_
, dir_index d_index_
,
40 unsigned int mod_time_
, unsigned int length_
)
47 /* Return the include directory at D_INDEX stored in LH. Returns
48 NULL if D_INDEX is out of bounds. */
49 const char *include_dir (const line_header
*lh
) const;
51 /* The file name. Note this is an observing pointer. The memory is
52 owned by debug_line_buffer. */
55 /* The directory index (1-based). */
58 unsigned int mod_time
{};
60 unsigned int length
{};
62 /* True if referenced by the Line Number Program. */
65 /* The associated symbol table, if any. */
66 struct symtab
*symtab
{};
69 /* The line number information for a compilation unit (found in the
70 .debug_line section) begins with a "statement program header",
71 which contains the following information. */
78 /* Add an entry to the include directory table. */
79 void add_include_dir (const char *include_dir
);
81 /* Add an entry to the file name table. */
82 void add_file_name (const char *name
, dir_index d_index
,
83 unsigned int mod_time
, unsigned int length
);
85 /* Return the include dir at INDEX (0-based in DWARF 5 and 1-based before).
86 Returns NULL if INDEX is out of bounds. */
87 const char *include_dir_at (dir_index index
) const
93 vec_index
= index
- 1;
94 if (vec_index
< 0 || vec_index
>= m_include_dirs
.size ())
96 return m_include_dirs
[vec_index
];
99 bool is_valid_file_index (int file_index
) const
102 return 0 <= file_index
&& file_index
< file_names_size ();
103 return 1 <= file_index
&& file_index
<= file_names_size ();
106 /* Return the file name at INDEX (0-based in DWARF 5 and 1-based before).
107 Returns NULL if INDEX is out of bounds. */
108 file_entry
*file_name_at (file_name_index index
)
114 vec_index
= index
- 1;
115 if (vec_index
< 0 || vec_index
>= m_file_names
.size ())
117 return &m_file_names
[vec_index
];
120 /* A const overload of the same. */
121 const file_entry
*file_name_at (file_name_index index
) const
123 line_header
*lh
= const_cast<line_header
*> (this);
124 return lh
->file_name_at (index
);
127 /* The indexes are 0-based in DWARF 5 and 1-based in DWARF 4. Therefore,
128 this method should only be used to iterate through all file entries in an
129 index-agnostic manner. */
130 std::vector
<file_entry
> &file_names ()
131 { return m_file_names
; }
132 /* A const overload of the same. */
133 const std::vector
<file_entry
> &file_names () const
134 { return m_file_names
; }
136 /* Offset of line number information in .debug_line section. */
137 sect_offset sect_off
{};
139 /* OFFSET is for struct dwz_file associated with dwarf2_per_objfile. */
140 unsigned offset_in_dwz
: 1; /* Can't initialize bitfields in-class. */
142 unsigned int total_length
{};
143 unsigned short version
{};
144 unsigned int header_length
{};
145 unsigned char minimum_instruction_length
{};
146 unsigned char maximum_ops_per_instruction
{};
147 unsigned char default_is_stmt
{};
149 unsigned char line_range
{};
150 unsigned char opcode_base
{};
152 /* standard_opcode_lengths[i] is the number of operands for the
153 standard opcode whose value is i. This means that
154 standard_opcode_lengths[0] is unused, and the last meaningful
155 element is standard_opcode_lengths[opcode_base - 1]. */
156 std::unique_ptr
<unsigned char[]> standard_opcode_lengths
;
158 int file_names_size () const
159 { return m_file_names
.size(); }
161 /* The start and end of the statement program following this
162 header. These point into dwarf2_per_objfile->line_buffer. */
163 const gdb_byte
*statement_program_start
{}, *statement_program_end
{};
165 /* Return file name relative to the compilation directory of file
166 number I in this object's file name table. The result is
167 allocated using xmalloc; the caller is responsible for freeing
169 gdb::unique_xmalloc_ptr
<char> file_file_name (int file
) const;
172 /* The include_directories table. Note these are observing
173 pointers. The memory is owned by debug_line_buffer. */
174 std::vector
<const char *> m_include_dirs
;
176 /* The file_names table. This is private because the meaning of indexes
177 differs among DWARF versions (The first valid index is 1 in DWARF 4 and
178 before, and is 0 in DWARF 5 and later). So the client should use
179 file_name_at method for access. */
180 std::vector
<file_entry
> m_file_names
;
183 typedef std::unique_ptr
<line_header
> line_header_up
;
186 file_entry::include_dir (const line_header
*lh
) const
188 return lh
->include_dir_at (d_index
);
191 /* Read the statement program header starting at SECT_OFF in SECTION.
192 Return line_header. Returns nullptr if there is a problem reading
193 the header, e.g., if it has a version we don't understand.
195 NOTE: the strings in the include directory and file name tables of
196 the returned object point into the dwarf line section buffer,
197 and must not be freed. */
199 extern line_header_up dwarf_decode_line_header
200 (sect_offset sect_off
, bool is_dwz
, dwarf2_per_objfile
*per_objfile
,
201 struct dwarf2_section_info
*section
, const struct comp_unit_head
*cu_header
);
203 #endif /* DWARF2_LINE_HEADER_H */