1 /* dwarf2dbg.c - DWARF2 debug support
2 Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
5 This file is part of GAS, the GNU Assembler.
7 GAS 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 2, or (at your option)
12 GAS 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 GAS; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* Logical line numbers can be controlled by the compiler via the
23 following two directives:
26 .loc FILENO LINENO [COLUMN]
28 FILENO is the filenumber. */
36 #ifdef HAVE_SYS_PARAM_H
37 #include <sys/param.h>
40 #define INT_MAX (int) (((unsigned) (-1)) >> 1)
46 #include "dwarf2dbg.h"
49 #include "elf/dwarf2.h"
51 /* Since we can't generate the prolog until the body is complete, we
52 use three different subsegments for .debug_line: one holding the
53 prolog, one for the directory and filename info, and one for the
54 body ("statement program"). */
59 /* First special line opcde - leave room for the standard opcodes.
60 Note: If you want to change this, you'll have to update the
61 "standard_opcode_lengths" table that is emitted below in
63 #define DWARF2_LINE_OPCODE_BASE 10
65 #ifndef DWARF2_LINE_BASE
66 /* Minimum line offset in a special line info. opcode. This value
67 was chosen to give a reasonable range of values. */
68 # define DWARF2_LINE_BASE -5
71 /* Range of line offsets in a special line info. opcode. */
72 #ifndef DWARF2_LINE_RANGE
73 # define DWARF2_LINE_RANGE 14
76 #ifndef DWARF2_LINE_MIN_INSN_LENGTH
77 /* Define the architecture-dependent minimum instruction length (in
78 bytes). This value should be rather too small than too big. */
79 # define DWARF2_LINE_MIN_INSN_LENGTH 1
82 /* Flag that indicates the initial value of the is_stmt_start flag.
83 In the present implementation, we do not mark any lines as
84 the beginning of a source statement, because that information
85 is not made available by the GCC front-end. */
86 #define DWARF2_LINE_DEFAULT_IS_STMT 1
88 /* Given a special op, return the line skip amount. */
89 #define SPECIAL_LINE(op) \
90 (((op) - DWARF2_LINE_OPCODE_BASE)%DWARF2_LINE_RANGE + DWARF2_LINE_BASE)
92 /* Given a special op, return the address skip amount (in units of
93 DWARF2_LINE_MIN_INSN_LENGTH. */
94 #define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE)
96 /* The maximum address skip amount that can be encoded with a special op. */
97 #define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255)
100 struct line_entry *next;
103 struct dwarf2_line_info loc;
107 struct line_subseg *next;
109 struct line_entry *head;
110 struct line_entry **ptail;
114 struct line_seg *next;
116 struct line_subseg *head;
121 /* Collects data for all line table entries during assembly. */
122 static struct line_seg *all_segs;
129 /* Table of files used by .debug_line. */
130 static struct file_entry *files;
131 static unsigned int files_in_use;
132 static unsigned int files_allocated;
134 /* True when we've seen a .loc directive recently. Used to avoid
135 doing work when there's nothing to do. */
136 static boolean loc_directive_seen;
138 /* Current location as indicated by the most recent .loc directive. */
139 static struct dwarf2_line_info current;
141 /* Fake label name. */
142 static char const fake_label_name[] = ".L0\001";
144 /* The size of an address on the target. */
145 static unsigned int sizeof_address;
147 static struct line_subseg *get_line_subseg PARAMS ((segT, subsegT));
148 static unsigned int get_filenum PARAMS ((const char *));
149 static struct frag *first_frag_for_seg PARAMS ((segT));
150 static struct frag *last_frag_for_seg PARAMS ((segT));
151 static void out_byte PARAMS ((int));
152 static void out_opcode PARAMS ((int));
153 static void out_two PARAMS ((int));
154 static void out_four PARAMS ((int));
155 static void out_abbrev PARAMS ((int, int));
156 static void out_uleb128 PARAMS ((addressT));
157 static symbolS *symbol_new_now PARAMS ((void));
158 static void set_symbol_value_now PARAMS ((symbolS *));
159 static offsetT get_frag_fix PARAMS ((fragS *));
160 static void out_set_addr PARAMS ((segT, fragS *, addressT));
161 static int size_inc_line_addr PARAMS ((int, addressT));
162 static void emit_inc_line_addr PARAMS ((int, addressT, char *, int));
163 static void out_inc_line_addr PARAMS ((int, addressT));
164 static void relax_inc_line_addr PARAMS ((int, segT, fragS *, addressT,
166 static void process_entries PARAMS ((segT, struct line_entry *));
167 static void out_file_list PARAMS ((void));
168 static void out_debug_line PARAMS ((segT));
169 static void out_debug_aranges PARAMS ((segT, segT));
170 static void out_debug_abbrev PARAMS ((segT));
171 static void out_debug_info PARAMS ((segT, segT, segT));
173 /* Find or create an entry for SEG+SUBSEG in ALL_SEGS. */
175 static struct line_subseg *
176 get_line_subseg (seg, subseg)
180 static segT last_seg;
181 static subsegT last_subseg;
182 static struct line_subseg *last_line_subseg;
185 struct line_subseg **pss, *ss;
187 if (seg == last_seg && subseg == last_subseg)
188 return last_line_subseg;
190 for (s = all_segs; s; s = s->next)
194 s = (struct line_seg *) xmalloc (sizeof (*s));
201 for (pss = &s->head; (ss = *pss) != NULL ; pss = &ss->next)
203 if (ss->subseg == subseg)
205 if (ss->subseg > subseg)
209 ss = (struct line_subseg *) xmalloc (sizeof (*ss));
213 ss->ptail = &ss->head;
218 last_subseg = subseg;
219 last_line_subseg = ss;
224 /* Record an entry for LOC ocurring at OFS within the current fragment. */
227 dwarf2_gen_line_info (ofs, loc)
229 struct dwarf2_line_info *loc;
231 struct line_subseg *ss;
232 struct line_entry *e;
234 /* Early out for as-yet incomplete location information. */
235 if (loc->filenum == 0 || loc->line == 0)
238 e = (struct line_entry *) xmalloc (sizeof (*e));
244 ss = get_line_subseg (now_seg, now_subseg);
246 ss->ptail = &e->next;
251 struct dwarf2_line_info *line;
253 if (debug_type == DEBUG_DWARF2)
256 as_where (&filename, &line->line);
257 line->filenum = get_filenum (filename);
259 line->flags = DWARF2_FLAG_BEGIN_STMT;
265 /* Called for each machine instruction, or relatively atomic group of
266 machine instructions (ie built-in macro). The instruction or group
267 is SIZE bytes in length. If dwarf2 line number generation is called
268 for, emit a line statement appropriately. */
271 dwarf2_emit_insn (size)
274 struct dwarf2_line_info loc;
276 if (debug_type != DEBUG_DWARF2 && ! loc_directive_seen)
278 loc_directive_seen = false;
281 dwarf2_gen_line_info (frag_now_fix () - size, &loc);
284 /* Get a .debug_line file number for FILENAME. */
287 get_filenum (filename)
288 const char *filename;
290 static unsigned int last_used;
294 if (strcmp (filename, files[last_used].filename) == 0)
297 for (i = 1; i < files_in_use; ++i)
298 if (strcmp (filename, files[i].filename) == 0)
301 if (i >= files_allocated)
303 unsigned int old = files_allocated;
305 files_allocated = i + 32;
306 files = (struct file_entry *)
307 xrealloc (files, (i + 32) * sizeof (struct file_entry));
309 memset (files + old, 0, (i + 32 - old) * sizeof (struct file_entry));
312 files[i].filename = xstrdup (filename);
314 files_in_use = i + 1;
320 /* Handle the .file directive. */
323 dwarf2_directive_file (dummy)
324 int dummy ATTRIBUTE_UNUSED;
327 const char *filename;
330 /* Continue to accept a bare string and pass it off. */
332 if (*input_line_pointer == '"')
338 num = get_absolute_expression ();
339 filename = demand_copy_C_string (&filename_len);
340 demand_empty_rest_of_line ();
344 as_bad (_("File number less than one"));
348 if (num < files_in_use && files[num].filename != 0)
350 as_bad (_("File number %d already allocated"), num);
354 if (num >= (int) files_allocated)
356 unsigned int old = files_allocated;
358 files_allocated = num + 16;
359 files = (struct file_entry *)
360 xrealloc (files, (num + 16) * sizeof (struct file_entry));
362 /* Zero the new memory. */
363 memset (files + old, 0, (num + 16 - old) * sizeof (struct file_entry));
366 files[num].filename = filename;
368 files_in_use = num + 1;
372 dwarf2_directive_loc (dummy)
373 int dummy ATTRIBUTE_UNUSED;
375 offsetT filenum, line, column;
377 filenum = get_absolute_expression ();
379 line = get_absolute_expression ();
381 column = get_absolute_expression ();
382 demand_empty_rest_of_line ();
386 as_bad (_("File number less than one"));
389 if (filenum >= (int) files_in_use || files[filenum].filename == 0)
391 as_bad (_("Unassigned file number %ld"), (long) filenum);
395 current.filenum = filenum;
397 current.column = column;
398 current.flags = DWARF2_FLAG_BEGIN_STMT;
400 loc_directive_seen = true;
404 listing_source_line (line);
409 first_frag_for_seg (seg)
412 frchainS *f, *first = NULL;
414 for (f = frchain_root; f; f = f->frch_next)
415 if (f->frch_seg == seg
416 && (! first || first->frch_subseg > f->frch_subseg))
419 return first ? first->frch_root : NULL;
423 last_frag_for_seg (seg)
426 frchainS *f, *last = NULL;
428 for (f = frchain_root; f; f = f->frch_next)
429 if (f->frch_seg == seg
430 && (! last || last->frch_subseg < f->frch_subseg))
433 return last ? last->frch_last : NULL;
436 /* Emit a single byte into the current segment. */
442 FRAG_APPEND_1_CHAR (byte);
445 /* Emit a statement program opcode into the current segment. */
454 /* Emit a two-byte word into the current segment. */
460 md_number_to_chars (frag_more (2), data, 2);
463 /* Emit a four byte word into the current segment. */
469 md_number_to_chars (frag_more (4), data, 4);
472 /* Emit an unsigned "little-endian base 128" number. */
478 output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
481 /* Emit a tuple for .debug_abbrev. */
484 out_abbrev (name, form)
491 /* Create a new fake symbol whose value is the current position. */
496 return symbol_new (fake_label_name, now_seg, frag_now_fix (), frag_now);
499 /* Set the value of SYM to the current position in the current segment. */
502 set_symbol_value_now (sym)
505 S_SET_SEGMENT (sym, now_seg);
506 S_SET_VALUE (sym, frag_now_fix ());
507 symbol_set_frag (sym, frag_now);
510 /* Get the size of a fragment. */
521 /* If a fragment is the last in the chain, special measures must be
522 taken to find its size before relaxation, since it may be pending
523 on some subsegment chain. */
524 for (fr = frchain_root; fr; fr = fr->frch_next)
525 if (fr->frch_last == frag)
527 return ((char *) obstack_next_free (&fr->frch_obstack)
534 /* Set an absolute address (may result in a relocation entry). */
537 out_set_addr (seg, frag, ofs)
545 sym = symbol_new (fake_label_name, seg, ofs, frag);
547 out_opcode (DW_LNS_extended_op);
548 out_uleb128 (sizeof_address + 1);
550 out_opcode (DW_LNE_set_address);
551 expr.X_op = O_symbol;
552 expr.X_add_symbol = sym;
553 expr.X_add_number = 0;
554 emit_expr (&expr, sizeof_address);
557 /* Encode a pair of line and address skips as efficiently as possible.
558 Note that the line skip is signed, whereas the address skip is unsigned.
560 The following two routines *must* be kept in sync. This is
561 enforced by making emit_inc_line_addr abort if we do not emit
562 exactly the expected number of bytes. */
565 size_inc_line_addr (line_delta, addr_delta)
569 unsigned int tmp, opcode;
572 /* Scale the address delta by the minimum instruction length. */
573 #if DWARF2_LINE_MIN_INSN_LENGTH > 1
574 assert (addr_delta % DWARF2_LINE_MIN_INSN_LENGTH == 0);
575 addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH;
578 /* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
579 We cannot use special opcodes here, since we want the end_sequence
580 to emit the matrix entry. */
581 if (line_delta == INT_MAX)
583 if (addr_delta == MAX_SPECIAL_ADDR_DELTA)
586 len = 1 + sizeof_leb128 (addr_delta, 0);
590 /* Bias the line delta by the base. */
591 tmp = line_delta - DWARF2_LINE_BASE;
593 /* If the line increment is out of range of a special opcode, we
594 must encode it with DW_LNS_advance_line. */
595 if (tmp >= DWARF2_LINE_RANGE)
597 len = 1 + sizeof_leb128 (line_delta, 1);
599 tmp = 0 - DWARF2_LINE_BASE;
602 /* Bias the opcode by the special opcode base. */
603 tmp += DWARF2_LINE_OPCODE_BASE;
605 /* Avoid overflow when addr_delta is large. */
606 if (addr_delta < 256 + MAX_SPECIAL_ADDR_DELTA)
608 /* Try using a special opcode. */
609 opcode = tmp + addr_delta * DWARF2_LINE_RANGE;
613 /* Try using DW_LNS_const_add_pc followed by special op. */
614 opcode = tmp + (addr_delta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
619 /* Otherwise use DW_LNS_advance_pc. */
620 len += 1 + sizeof_leb128 (addr_delta, 0);
622 /* DW_LNS_copy or special opcode. */
629 emit_inc_line_addr (line_delta, addr_delta, p, len)
635 unsigned int tmp, opcode;
639 #if DWARF2_LINE_MIN_INSN_LENGTH > 1
640 /* Scale the address delta by the minimum instruction length. */
641 assert (addr_delta % DWARF2_LINE_MIN_INSN_LENGTH == 0);
642 addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH;
644 /* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
645 We cannot use special opcodes here, since we want the end_sequence
646 to emit the matrix entry. */
647 if (line_delta == INT_MAX)
649 if (addr_delta == MAX_SPECIAL_ADDR_DELTA)
650 *p++ = DW_LNS_const_add_pc;
653 *p++ = DW_LNS_advance_pc;
654 p += output_leb128 (p, addr_delta, 0);
657 *p++ = DW_LNS_extended_op;
659 *p++ = DW_LNE_end_sequence;
663 /* Bias the line delta by the base. */
664 tmp = line_delta - DWARF2_LINE_BASE;
666 /* If the line increment is out of range of a special opcode, we
667 must encode it with DW_LNS_advance_line. */
668 if (tmp >= DWARF2_LINE_RANGE)
670 *p++ = DW_LNS_advance_line;
671 p += output_leb128 (p, line_delta, 1);
673 /* Prettier, I think, to use DW_LNS_copy instead of a
674 "line +0, addr +0" special opcode. */
682 tmp = 0 - DWARF2_LINE_BASE;
686 /* Bias the opcode by the special opcode base. */
687 tmp += DWARF2_LINE_OPCODE_BASE;
689 /* Avoid overflow when addr_delta is large. */
690 if (addr_delta < 256 + MAX_SPECIAL_ADDR_DELTA)
692 /* Try using a special opcode. */
693 opcode = tmp + addr_delta * DWARF2_LINE_RANGE;
700 /* Try using DW_LNS_const_add_pc followed by special op. */
701 opcode = tmp + (addr_delta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
704 *p++ = DW_LNS_const_add_pc;
710 /* Otherwise use DW_LNS_advance_pc. */
711 *p++ = DW_LNS_advance_pc;
712 p += output_leb128 (p, addr_delta, 0);
723 /* Handy routine to combine calls to the above two routines. */
726 out_inc_line_addr (line_delta, addr_delta)
730 int len = size_inc_line_addr (line_delta, addr_delta);
731 emit_inc_line_addr (line_delta, addr_delta, frag_more (len), len);
734 /* Generate a variant frag that we can use to relax address/line
735 increments between fragments of the target segment. */
738 relax_inc_line_addr (line_delta, seg, to_frag, to_ofs, from_frag, from_ofs)
741 fragS *to_frag, *from_frag;
742 addressT to_ofs, from_ofs;
744 symbolS *to_sym, *from_sym;
748 to_sym = symbol_new (fake_label_name, seg, to_ofs, to_frag);
749 from_sym = symbol_new (fake_label_name, seg, from_ofs, from_frag);
751 expr.X_op = O_subtract;
752 expr.X_add_symbol = to_sym;
753 expr.X_op_symbol = from_sym;
754 expr.X_add_number = 0;
756 /* The maximum size of the frag is the line delta with a maximum
757 sized address delta. */
758 max_chars = size_inc_line_addr (line_delta, -DWARF2_LINE_MIN_INSN_LENGTH);
760 frag_var (rs_dwarf2dbg, max_chars, max_chars, 1,
761 make_expr_symbol (&expr), line_delta, NULL);
764 /* The function estimates the size of a rs_dwarf2dbg variant frag
765 based on the current values of the symbols. It is called before
766 the relaxation loop. We set fr_subtype to the expected length. */
769 dwarf2dbg_estimate_size_before_relax (frag)
775 addr_delta = resolve_symbol_value (frag->fr_symbol, 0);
776 size = size_inc_line_addr (frag->fr_offset, addr_delta);
778 frag->fr_subtype = size;
783 /* This function relaxes a rs_dwarf2dbg variant frag based on the
784 current values of the symbols. fr_subtype is the current length
785 of the frag. This returns the change in frag length. */
788 dwarf2dbg_relax_frag (frag)
791 int old_size, new_size;
793 old_size = frag->fr_subtype;
794 new_size = dwarf2dbg_estimate_size_before_relax (frag);
796 return new_size - old_size;
799 /* This function converts a rs_dwarf2dbg variant frag into a normal
800 fill frag. This is called after all relaxation has been done.
801 fr_subtype will be the desired length of the frag. */
804 dwarf2dbg_convert_frag (frag)
809 addr_diff = resolve_symbol_value (frag->fr_symbol, 1);
811 /* fr_var carries the max_chars that we created the fragment with.
812 fr_subtype carries the current expected length. We must, of
813 course, have allocated enough memory earlier. */
814 assert (frag->fr_var >= (int) frag->fr_subtype);
816 emit_inc_line_addr (frag->fr_offset, addr_diff,
817 frag->fr_literal + frag->fr_fix, frag->fr_subtype);
819 frag->fr_fix += frag->fr_subtype;
820 frag->fr_type = rs_fill;
825 /* Generate .debug_line content for the chain of line number entries
826 beginning at E, for segment SEG. */
829 process_entries (seg, e)
831 struct line_entry *e;
833 unsigned filenum = 1;
836 unsigned flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_BEGIN_STMT : 0;
839 addressT frag_ofs = 0;
840 addressT last_frag_ofs;
841 struct line_entry *next;
847 if (filenum != e->loc.filenum)
849 filenum = e->loc.filenum;
850 out_opcode (DW_LNS_set_file);
851 out_uleb128 (filenum);
855 if (column != e->loc.column)
857 column = e->loc.column;
858 out_opcode (DW_LNS_set_column);
859 out_uleb128 (column);
863 if ((e->loc.flags ^ flags) & DWARF2_FLAG_BEGIN_STMT)
865 flags = e->loc.flags;
866 out_opcode (DW_LNS_negate_stmt);
870 if (e->loc.flags & DWARF2_FLAG_BEGIN_BLOCK)
872 out_opcode (DW_LNS_set_basic_block);
876 if (line != e->loc.line || changed)
878 int line_delta = e->loc.line - line;
881 out_set_addr (seg, e->frag, e->frag_ofs);
882 out_inc_line_addr (line_delta, 0);
884 else if (frag == e->frag)
885 out_inc_line_addr (line_delta, e->frag_ofs - frag_ofs);
887 relax_inc_line_addr (line_delta, seg, e->frag, e->frag_ofs,
891 frag_ofs = e->frag_ofs;
894 else if (frag == NULL)
896 out_set_addr (seg, e->frag, e->frag_ofs);
898 frag_ofs = e->frag_ofs;
906 /* Emit a DW_LNE_end_sequence for the end of the section. */
907 last_frag = last_frag_for_seg (seg);
908 last_frag_ofs = get_frag_fix (last_frag);
909 if (frag == last_frag)
910 out_inc_line_addr (INT_MAX, last_frag_ofs - frag_ofs);
912 relax_inc_line_addr (INT_MAX, seg, last_frag, last_frag_ofs,
916 /* Emit the directory and file tables for .debug_line. */
925 /* Terminate directory list. */
928 for (i = 1; i < files_in_use; ++i)
930 if (files[i].filename == NULL)
932 as_bad (_("Unassigned file number %u"), i);
936 size = strlen (files[i].filename) + 1;
937 cp = frag_more (size);
938 memcpy (cp, files[i].filename, size);
940 out_uleb128 (files[i].dir); /* directory number */
941 out_uleb128 (0); /* last modification timestamp */
942 out_uleb128 (0); /* filesize */
945 /* Terminate filename list. */
949 /* Emit the collected .debug_line data. */
952 out_debug_line (line_seg)
957 symbolS *prologue_end;
961 subseg_set (line_seg, 0);
963 line_start = symbol_new_now ();
964 prologue_end = symbol_make (fake_label_name);
965 line_end = symbol_make (fake_label_name);
967 /* Total length of the information for this compilation unit. */
968 expr.X_op = O_subtract;
969 expr.X_add_symbol = line_end;
970 expr.X_op_symbol = line_start;
971 expr.X_add_number = -4;
972 emit_expr (&expr, 4);
977 /* Length of the prologue following this length. */
978 expr.X_op = O_subtract;
979 expr.X_add_symbol = prologue_end;
980 expr.X_op_symbol = line_start;
981 expr.X_add_number = - (4 + 2 + 4);
982 emit_expr (&expr, 4);
984 /* Parameters of the state machine. */
985 out_byte (DWARF2_LINE_MIN_INSN_LENGTH);
986 out_byte (DWARF2_LINE_DEFAULT_IS_STMT);
987 out_byte (DWARF2_LINE_BASE);
988 out_byte (DWARF2_LINE_RANGE);
989 out_byte (DWARF2_LINE_OPCODE_BASE);
991 /* Standard opcode lengths. */
992 out_byte (0); /* DW_LNS_copy */
993 out_byte (1); /* DW_LNS_advance_pc */
994 out_byte (1); /* DW_LNS_advance_line */
995 out_byte (1); /* DW_LNS_set_file */
996 out_byte (1); /* DW_LNS_set_column */
997 out_byte (0); /* DW_LNS_negate_stmt */
998 out_byte (0); /* DW_LNS_set_basic_block */
999 out_byte (0); /* DW_LNS_const_add_pc */
1000 out_byte (1); /* DW_LNS_fixed_advance_pc */
1004 set_symbol_value_now (prologue_end);
1006 /* For each section, emit a statement program. */
1007 for (s = all_segs; s; s = s->next)
1008 process_entries (s->seg, s->head->head);
1010 set_symbol_value_now (line_end);
1013 /* Emit data for .debug_aranges. */
1016 out_debug_aranges (aranges_seg, info_seg)
1020 unsigned int addr_size = sizeof_address;
1021 addressT size, skip;
1026 size = 4 + 2 + 4 + 1 + 1;
1028 skip = 2 * addr_size - (size & (2 * addr_size - 1));
1029 if (skip == 2 * addr_size)
1033 for (s = all_segs; s; s = s->next)
1034 size += 2 * addr_size;
1036 size += 2 * addr_size;
1038 subseg_set (aranges_seg, 0);
1040 /* Length of the compilation unit. */
1041 out_four (size - 4);
1046 /* Offset to .debug_info. */
1047 expr.X_op = O_symbol;
1048 expr.X_add_symbol = section_symbol (info_seg);
1049 expr.X_add_number = 0;
1050 emit_expr (&expr, 4);
1052 /* Size of an address (offset portion). */
1053 out_byte (addr_size);
1055 /* Size of a segment descriptor. */
1058 /* Align the header. */
1060 frag_align (ffs (2 * addr_size) - 1, 0, 0);
1062 for (s = all_segs; s; s = s->next)
1067 frag = first_frag_for_seg (s->seg);
1068 beg = symbol_new (fake_label_name, s->seg, 0, frag);
1069 s->text_start = beg;
1071 frag = last_frag_for_seg (s->seg);
1072 end = symbol_new (fake_label_name, s->seg, get_frag_fix (frag), frag);
1075 expr.X_op = O_symbol;
1076 expr.X_add_symbol = beg;
1077 expr.X_add_number = 0;
1078 emit_expr (&expr, addr_size);
1080 expr.X_op = O_subtract;
1081 expr.X_add_symbol = end;
1082 expr.X_op_symbol = beg;
1083 expr.X_add_number = 0;
1084 emit_expr (&expr, addr_size);
1087 p = frag_more (2 * addr_size);
1088 md_number_to_chars (p, 0, addr_size);
1089 md_number_to_chars (p + addr_size, 0, addr_size);
1092 /* Emit data for .debug_abbrev. Note that this must be kept in
1093 sync with out_debug_info below. */
1096 out_debug_abbrev (abbrev_seg)
1099 subseg_set (abbrev_seg, 0);
1102 out_uleb128 (DW_TAG_compile_unit);
1103 out_byte (DW_CHILDREN_no);
1104 out_abbrev (DW_AT_stmt_list, DW_FORM_data4);
1105 if (all_segs->next == NULL)
1107 out_abbrev (DW_AT_low_pc, DW_FORM_addr);
1108 out_abbrev (DW_AT_high_pc, DW_FORM_addr);
1110 out_abbrev (DW_AT_comp_dir, DW_FORM_string);
1111 out_abbrev (DW_AT_producer, DW_FORM_string);
1112 out_abbrev (DW_AT_language, DW_FORM_data2);
1115 /* Terminate the abbreviations for this compilation unit. */
1119 /* Emit a description of this compilation unit for .debug_info. */
1122 out_debug_info (info_seg, abbrev_seg, line_seg)
1130 symbolS *info_start;
1135 subseg_set (info_seg, 0);
1137 info_start = symbol_new_now ();
1138 info_end = symbol_make (fake_label_name);
1140 /* Compilation Unit length. */
1141 expr.X_op = O_subtract;
1142 expr.X_add_symbol = info_end;
1143 expr.X_op_symbol = info_start;
1144 expr.X_add_number = -4;
1145 emit_expr (&expr, 4);
1147 /* DWARF version. */
1150 /* .debug_abbrev offset */
1151 expr.X_op = O_symbol;
1152 expr.X_add_symbol = section_symbol (abbrev_seg);
1153 expr.X_add_number = 0;
1154 emit_expr (&expr, 4);
1156 /* Target address size. */
1157 out_byte (sizeof_address);
1159 /* DW_TAG_compile_unit DIE abbrev */
1162 /* DW_AT_stmt_list */
1163 expr.X_op = O_symbol;
1164 expr.X_add_symbol = section_symbol (line_seg);
1165 expr.X_add_number = 0;
1166 emit_expr (&expr, 4);
1168 /* These two attributes may only be emitted if all of the code is
1169 contiguous. Multiple sections are not that. */
1170 if (all_segs->next == NULL)
1173 expr.X_op = O_symbol;
1174 expr.X_add_symbol = all_segs->text_start;
1175 expr.X_add_number = 0;
1176 emit_expr (&expr, sizeof_address);
1179 expr.X_op = O_symbol;
1180 expr.X_add_symbol = all_segs->text_end;
1181 expr.X_add_number = 0;
1182 emit_expr (&expr, sizeof_address);
1185 /* DW_AT_comp_dir */
1186 comp_dir = getpwd ();
1187 len = strlen (comp_dir) + 1;
1188 p = frag_more (len);
1189 memcpy (p, comp_dir, len);
1191 /* DW_AT_producer */
1192 sprintf (producer, "GNU AS %s", VERSION);
1193 len = strlen (producer) + 1;
1194 p = frag_more (len);
1195 memcpy (p, producer, len);
1197 /* DW_AT_language. Yes, this is probably not really MIPS, but the
1198 dwarf2 draft has no standard code for assembler. */
1199 out_two (DW_LANG_Mips_Assembler);
1201 set_symbol_value_now (info_end);
1210 /* If no debug information was recorded, nothing to do. */
1211 if (all_segs == NULL)
1214 /* Calculate the size of an address for the target machine. */
1215 sizeof_address = bfd_arch_bits_per_address (stdoutput) / 8;
1217 /* Create and switch to the line number section. */
1218 line_seg = subseg_new (".debug_line", 0);
1219 bfd_set_section_flags (stdoutput, line_seg, SEC_READONLY);
1221 /* For each subsection, chain the debug entries together. */
1222 for (s = all_segs; s; s = s->next)
1224 struct line_subseg *ss = s->head;
1225 struct line_entry **ptail = ss->ptail;
1227 while ((ss = ss->next) != NULL)
1234 out_debug_line (line_seg);
1236 /* If this is assembler generated line info, we need .debug_info
1237 and .debug_abbrev sections as well. */
1238 if (debug_type == DEBUG_DWARF2)
1244 info_seg = subseg_new (".debug_info", 0);
1245 abbrev_seg = subseg_new (".debug_abbrev", 0);
1246 aranges_seg = subseg_new (".debug_aranges", 0);
1248 bfd_set_section_flags (stdoutput, info_seg, SEC_READONLY);
1249 bfd_set_section_flags (stdoutput, abbrev_seg, SEC_READONLY);
1250 bfd_set_section_flags (stdoutput, aranges_seg, SEC_READONLY);
1252 record_alignment (aranges_seg, ffs (2 * sizeof_address) - 1);
1254 out_debug_aranges (aranges_seg, info_seg);
1255 out_debug_abbrev (abbrev_seg);
1256 out_debug_info (info_seg, abbrev_seg, line_seg);
1267 dwarf2dbg_estimate_size_before_relax (frag)
1268 fragS *frag ATTRIBUTE_UNUSED;
1270 as_fatal (_("dwarf2 is not supported for this object file format"));
1275 dwarf2dbg_relax_frag (frag)
1276 fragS *frag ATTRIBUTE_UNUSED;
1278 as_fatal (_("dwarf2 is not supported for this object file format"));
1283 dwarf2dbg_convert_frag (frag)
1284 fragS *frag ATTRIBUTE_UNUSED;
1286 as_fatal (_("dwarf2 is not supported for this object file format"));
1290 dwarf2_emit_insn (size)
1291 int size ATTRIBUTE_UNUSED;
1296 dwarf2_directive_file (dummy)
1297 int dummy ATTRIBUTE_UNUSED;
1303 dwarf2_directive_loc (dummy)
1304 int dummy ATTRIBUTE_UNUSED;
1306 as_fatal (_("dwarf2 is not supported for this object file format"));
1308 #endif /* BFD_ASSEMBLER */