| /* DWARF 2 debugging format support for GDB. |
| |
| Copyright (C) 1994-2021 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/>. */ |
| |
| #include "defs.h" |
| #include "dwarf2/comp-unit-head.h" |
| #include "dwarf2/leb.h" |
| #include "dwarf2/line-header.h" |
| #include "dwarf2/read.h" |
| #include "complaints.h" |
| #include "filenames.h" |
| |
| void |
| line_header::add_include_dir (const char *include_dir) |
| { |
| if (dwarf_line_debug >= 2) |
| { |
| size_t new_size; |
| if (version >= 5) |
| new_size = m_include_dirs.size (); |
| else |
| new_size = m_include_dirs.size () + 1; |
| fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n", |
| new_size, include_dir); |
| } |
| m_include_dirs.push_back (include_dir); |
| } |
| |
| void |
| line_header::add_file_name (const char *name, |
| dir_index d_index, |
| unsigned int mod_time, |
| unsigned int length) |
| { |
| if (dwarf_line_debug >= 2) |
| { |
| size_t new_size; |
| if (version >= 5) |
| new_size = file_names_size (); |
| else |
| new_size = file_names_size () + 1; |
| fprintf_unfiltered (gdb_stdlog, "Adding file %zu: %s\n", |
| new_size, name); |
| } |
| m_file_names.emplace_back (name, d_index, mod_time, length); |
| } |
| |
| gdb::unique_xmalloc_ptr<char> |
| line_header::file_file_name (int file) const |
| { |
| /* Is the file number a valid index into the line header's file name |
| table? Remember that file numbers start with one, not zero. */ |
| if (is_valid_file_index (file)) |
| { |
| const file_entry *fe = file_name_at (file); |
| |
| if (!IS_ABSOLUTE_PATH (fe->name)) |
| { |
| const char *dir = fe->include_dir (this); |
| if (dir != NULL) |
| return gdb::unique_xmalloc_ptr<char> (concat (dir, SLASH_STRING, |
| fe->name, |
| (char *) NULL)); |
| } |
| return make_unique_xstrdup (fe->name); |
| } |
| else |
| { |
| /* The compiler produced a bogus file number. We can at least |
| record the macro definitions made in the file, even if we |
| won't be able to find the file by name. */ |
| char fake_name[80]; |
| |
| xsnprintf (fake_name, sizeof (fake_name), |
| "<bad macro file number %d>", file); |
| |
| complaint (_("bad file number in macro information (%d)"), |
| file); |
| |
| return make_unique_xstrdup (fake_name); |
| } |
| } |
| |
| static void |
| dwarf2_statement_list_fits_in_line_number_section_complaint (void) |
| { |
| complaint (_("statement list doesn't fit in .debug_line section")); |
| } |
| |
| /* Cover function for read_initial_length. |
| Returns the length of the object at BUF, and stores the size of the |
| initial length in *BYTES_READ and stores the size that offsets will be in |
| *OFFSET_SIZE. |
| If the initial length size is not equivalent to that specified in |
| CU_HEADER then issue a complaint. |
| This is useful when reading non-comp-unit headers. */ |
| |
| static LONGEST |
| read_checked_initial_length_and_offset (bfd *abfd, const gdb_byte *buf, |
| const struct comp_unit_head *cu_header, |
| unsigned int *bytes_read, |
| unsigned int *offset_size) |
| { |
| LONGEST length = read_initial_length (abfd, buf, bytes_read); |
| |
| gdb_assert (cu_header->initial_length_size == 4 |
| || cu_header->initial_length_size == 8 |
| || cu_header->initial_length_size == 12); |
| |
| if (cu_header->initial_length_size != *bytes_read) |
| complaint (_("intermixed 32-bit and 64-bit DWARF sections")); |
| |
| *offset_size = (*bytes_read == 4) ? 4 : 8; |
| return length; |
| } |
| |
| /* Read directory or file name entry format, starting with byte of |
| format count entries, ULEB128 pairs of entry formats, ULEB128 of |
| entries count and the entries themselves in the described entry |
| format. */ |
| |
| static void |
| read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd, |
| const gdb_byte **bufp, struct line_header *lh, |
| const struct comp_unit_head *cu_header, |
| void (*callback) (struct line_header *lh, |
| const char *name, |
| dir_index d_index, |
| unsigned int mod_time, |
| unsigned int length)) |
| { |
| gdb_byte format_count, formati; |
| ULONGEST data_count, datai; |
| const gdb_byte *buf = *bufp; |
| const gdb_byte *format_header_data; |
| unsigned int bytes_read; |
| |
| format_count = read_1_byte (abfd, buf); |
| buf += 1; |
| format_header_data = buf; |
| for (formati = 0; formati < format_count; formati++) |
| { |
| read_unsigned_leb128 (abfd, buf, &bytes_read); |
| buf += bytes_read; |
| read_unsigned_leb128 (abfd, buf, &bytes_read); |
| buf += bytes_read; |
| } |
| |
| data_count = read_unsigned_leb128 (abfd, buf, &bytes_read); |
| buf += bytes_read; |
| for (datai = 0; datai < data_count; datai++) |
| { |
| const gdb_byte *format = format_header_data; |
| struct file_entry fe; |
| |
| for (formati = 0; formati < format_count; formati++) |
| { |
| ULONGEST content_type = read_unsigned_leb128 (abfd, format, &bytes_read); |
| format += bytes_read; |
| |
| ULONGEST form = read_unsigned_leb128 (abfd, format, &bytes_read); |
| format += bytes_read; |
| |
| gdb::optional<const char *> string; |
| gdb::optional<unsigned int> uint; |
| |
| switch (form) |
| { |
| case DW_FORM_string: |
| string.emplace (read_direct_string (abfd, buf, &bytes_read)); |
| buf += bytes_read; |
| break; |
| |
| case DW_FORM_line_strp: |
| string.emplace |
| (per_objfile->read_line_string (buf, cu_header, &bytes_read)); |
| buf += bytes_read; |
| break; |
| |
| case DW_FORM_data1: |
| uint.emplace (read_1_byte (abfd, buf)); |
| buf += 1; |
| break; |
| |
| case DW_FORM_data2: |
| uint.emplace (read_2_bytes (abfd, buf)); |
| buf += 2; |
| break; |
| |
| case DW_FORM_data4: |
| uint.emplace (read_4_bytes (abfd, buf)); |
| buf += 4; |
| break; |
| |
| case DW_FORM_data8: |
| uint.emplace (read_8_bytes (abfd, buf)); |
| buf += 8; |
| break; |
| |
| case DW_FORM_data16: |
| /* This is used for MD5, but file_entry does not record MD5s. */ |
| buf += 16; |
| break; |
| |
| case DW_FORM_udata: |
| uint.emplace (read_unsigned_leb128 (abfd, buf, &bytes_read)); |
| buf += bytes_read; |
| break; |
| |
| case DW_FORM_block: |
| /* It is valid only for DW_LNCT_timestamp which is ignored by |
| current GDB. */ |
| break; |
| } |
| |
| switch (content_type) |
| { |
| case DW_LNCT_path: |
| if (string.has_value ()) |
| fe.name = *string; |
| break; |
| case DW_LNCT_directory_index: |
| if (uint.has_value ()) |
| fe.d_index = (dir_index) *uint; |
| break; |
| case DW_LNCT_timestamp: |
| if (uint.has_value ()) |
| fe.mod_time = *uint; |
| break; |
| case DW_LNCT_size: |
| if (uint.has_value ()) |
| fe.length = *uint; |
| break; |
| case DW_LNCT_MD5: |
| break; |
| default: |
| complaint (_("Unknown format content type %s"), |
| pulongest (content_type)); |
| } |
| } |
| |
| callback (lh, fe.name, fe.d_index, fe.mod_time, fe.length); |
| } |
| |
| *bufp = buf; |
| } |
| |
| /* See line-header.h. */ |
| |
| 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) |
| { |
| const gdb_byte *line_ptr; |
| unsigned int bytes_read, offset_size; |
| int i; |
| const char *cur_dir, *cur_file; |
| |
| bfd *abfd = section->get_bfd_owner (); |
| |
| /* Make sure that at least there's room for the total_length field. |
| That could be 12 bytes long, but we're just going to fudge that. */ |
| if (to_underlying (sect_off) + 4 >= section->size) |
| { |
| dwarf2_statement_list_fits_in_line_number_section_complaint (); |
| return 0; |
| } |
| |
| line_header_up lh (new line_header ()); |
| |
| lh->sect_off = sect_off; |
| lh->offset_in_dwz = is_dwz; |
| |
| line_ptr = section->buffer + to_underlying (sect_off); |
| |
| /* Read in the header. */ |
| lh->total_length = |
| read_checked_initial_length_and_offset (abfd, line_ptr, cu_header, |
| &bytes_read, &offset_size); |
| line_ptr += bytes_read; |
| |
| const gdb_byte *start_here = line_ptr; |
| |
| if (line_ptr + lh->total_length > (section->buffer + section->size)) |
| { |
| dwarf2_statement_list_fits_in_line_number_section_complaint (); |
| return 0; |
| } |
| lh->statement_program_end = start_here + lh->total_length; |
| lh->version = read_2_bytes (abfd, line_ptr); |
| line_ptr += 2; |
| if (lh->version > 5) |
| { |
| /* This is a version we don't understand. The format could have |
| changed in ways we don't handle properly so just punt. */ |
| complaint (_("unsupported version in .debug_line section")); |
| return NULL; |
| } |
| if (lh->version >= 5) |
| { |
| gdb_byte segment_selector_size; |
| |
| /* Skip address size. */ |
| read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| |
| segment_selector_size = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| if (segment_selector_size != 0) |
| { |
| complaint (_("unsupported segment selector size %u " |
| "in .debug_line section"), |
| segment_selector_size); |
| return NULL; |
| } |
| } |
| lh->header_length = read_offset (abfd, line_ptr, offset_size); |
| line_ptr += offset_size; |
| lh->statement_program_start = line_ptr + lh->header_length; |
| lh->minimum_instruction_length = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| if (lh->version >= 4) |
| { |
| lh->maximum_ops_per_instruction = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| } |
| else |
| lh->maximum_ops_per_instruction = 1; |
| |
| if (lh->maximum_ops_per_instruction == 0) |
| { |
| lh->maximum_ops_per_instruction = 1; |
| complaint (_("invalid maximum_ops_per_instruction " |
| "in `.debug_line' section")); |
| } |
| |
| lh->default_is_stmt = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| lh->line_base = read_1_signed_byte (abfd, line_ptr); |
| line_ptr += 1; |
| lh->line_range = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| lh->opcode_base = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| lh->standard_opcode_lengths.reset (new unsigned char[lh->opcode_base]); |
| |
| lh->standard_opcode_lengths[0] = 1; /* This should never be used anyway. */ |
| for (i = 1; i < lh->opcode_base; ++i) |
| { |
| lh->standard_opcode_lengths[i] = read_1_byte (abfd, line_ptr); |
| line_ptr += 1; |
| } |
| |
| if (lh->version >= 5) |
| { |
| /* Read directory table. */ |
| read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (), |
| cu_header, |
| [] (struct line_header *header, const char *name, |
| dir_index d_index, unsigned int mod_time, |
| unsigned int length) |
| { |
| header->add_include_dir (name); |
| }); |
| |
| /* Read file name table. */ |
| read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (), |
| cu_header, |
| [] (struct line_header *header, const char *name, |
| dir_index d_index, unsigned int mod_time, |
| unsigned int length) |
| { |
| header->add_file_name (name, d_index, mod_time, length); |
| }); |
| } |
| else |
| { |
| /* Read directory table. */ |
| while ((cur_dir = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) |
| { |
| line_ptr += bytes_read; |
| lh->add_include_dir (cur_dir); |
| } |
| line_ptr += bytes_read; |
| |
| /* Read file name table. */ |
| while ((cur_file = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) |
| { |
| unsigned int mod_time, length; |
| dir_index d_index; |
| |
| line_ptr += bytes_read; |
| d_index = (dir_index) read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| line_ptr += bytes_read; |
| mod_time = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| line_ptr += bytes_read; |
| length = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| line_ptr += bytes_read; |
| |
| lh->add_file_name (cur_file, d_index, mod_time, length); |
| } |
| line_ptr += bytes_read; |
| } |
| |
| if (line_ptr > (section->buffer + section->size)) |
| complaint (_("line number info header doesn't " |
| "fit in `.debug_line' section")); |
| |
| return lh; |
| } |