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/* DWARF 2 debugging format support for GDB.
Copyright (C) 1994-2022 Free Software Foundation, Inc.
This file is part of GDB.
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, see <http://www.gnu.org/licenses/>. */
#ifndef DWARF2_LINE_HEADER_H
#define DWARF2_LINE_HEADER_H
#include "gdbtypes.h"
/* dir_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 and
later. */
typedef int dir_index;
/* file_name_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5
and later. */
typedef int file_name_index;
struct line_header;
struct file_entry
{
file_entry () = default;
file_entry (const char *name_, dir_index d_index_,
unsigned int mod_time_, unsigned int length_)
: name (name_),
d_index (d_index_),
mod_time (mod_time_),
length (length_)
{}
/* Return the include directory at D_INDEX stored in LH. Returns
NULL if D_INDEX is out of bounds. */
const char *include_dir (const line_header *lh) const;
/* The file name. Note this is an observing pointer. The memory is
owned by debug_line_buffer. */
const char *name {};
/* The directory index (1-based). */
dir_index d_index {};
unsigned int mod_time {};
unsigned int length {};
/* The associated symbol table, if any. */
struct symtab *symtab {};
};
/* The line number information for a compilation unit (found in the
.debug_line section) begins with a "statement program header",
which contains the following information. */
struct line_header
{
line_header ()
: offset_in_dwz {}
{}
/* Add an entry to the include directory table. */
void add_include_dir (const char *include_dir);
/* Add an entry to the file name table. */
void add_file_name (const char *name, dir_index d_index,
unsigned int mod_time, unsigned int length);
/* Return the include dir at INDEX (0-based in DWARF 5 and 1-based before).
Returns NULL if INDEX is out of bounds. */
const char *include_dir_at (dir_index index) const
{
int vec_index;
if (version >= 5)
vec_index = index;
else
vec_index = index - 1;
if (vec_index < 0 || vec_index >= m_include_dirs.size ())
return NULL;
return m_include_dirs[vec_index];
}
bool is_valid_file_index (int file_index) const
{
if (version >= 5)
return 0 <= file_index && file_index < file_names_size ();
return 1 <= file_index && file_index <= file_names_size ();
}
/* Return the file name at INDEX (0-based in DWARF 5 and 1-based before).
Returns NULL if INDEX is out of bounds. */
file_entry *file_name_at (file_name_index index)
{
int vec_index;
if (version >= 5)
vec_index = index;
else
vec_index = index - 1;
if (vec_index < 0 || vec_index >= m_file_names.size ())
return NULL;
return &m_file_names[vec_index];
}
/* A const overload of the same. */
const file_entry *file_name_at (file_name_index index) const
{
line_header *lh = const_cast<line_header *> (this);
return lh->file_name_at (index);
}
/* The indexes are 0-based in DWARF 5 and 1-based in DWARF 4. Therefore,
this method should only be used to iterate through all file entries in an
index-agnostic manner. */
std::vector<file_entry> &file_names ()
{ return m_file_names; }
/* A const overload of the same. */
const std::vector<file_entry> &file_names () const
{ return m_file_names; }
/* Offset of line number information in .debug_line section. */
sect_offset sect_off {};
/* OFFSET is for struct dwz_file associated with dwarf2_per_objfile. */
unsigned offset_in_dwz : 1; /* Can't initialize bitfields in-class. */
unsigned short version {};
unsigned char minimum_instruction_length {};
unsigned char maximum_ops_per_instruction {};
unsigned char default_is_stmt {};
int line_base {};
unsigned char line_range {};
unsigned char opcode_base {};
/* standard_opcode_lengths[i] is the number of operands for the
standard opcode whose value is i. This means that
standard_opcode_lengths[0] is unused, and the last meaningful
element is standard_opcode_lengths[opcode_base - 1]. */
std::unique_ptr<unsigned char[]> standard_opcode_lengths;
int file_names_size () const
{ return m_file_names.size(); }
/* The start and end of the statement program following this
header. These point into dwarf2_per_objfile->line_buffer. */
const gdb_byte *statement_program_start {}, *statement_program_end {};
/* Return file name relative to the compilation directory of file
number FILE in this object's file name table. */
std::string file_file_name (int file) const;
private:
/* The include_directories table. Note these are observing
pointers. The memory is owned by debug_line_buffer. */
std::vector<const char *> m_include_dirs;
/* The file_names table. This is private because the meaning of indexes
differs among DWARF versions (The first valid index is 1 in DWARF 4 and
before, and is 0 in DWARF 5 and later). So the client should use
file_name_at method for access. */
std::vector<file_entry> m_file_names;
};
typedef std::unique_ptr<line_header> line_header_up;
inline const char *
file_entry::include_dir (const line_header *lh) const
{
return lh->include_dir_at (d_index);
}
/* Read the statement program header starting at SECT_OFF in SECTION.
Return line_header. Returns nullptr if there is a problem reading
the header, e.g., if it has a version we don't understand.
NOTE: the strings in the include directory and file name tables of
the returned object point into the dwarf line section buffer,
and must not be freed. */
extern line_header_up dwarf_decode_line_header
(sect_offset sect_off, bool is_dwz, dwarf2_per_objfile *per_objfile,
struct dwarf2_section_info *section, const struct comp_unit_head *cu_header);
#endif /* DWARF2_LINE_HEADER_H */
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