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
;
233 static unsigned int line
= -1;
234 static unsigned int filenum
= -1;
236 /* Early out for as-yet incomplete location information. */
237 if (loc
->filenum
== 0 || loc
->line
== 0)
240 /* Don't emit sequences of line symbols for the same line when the
241 symbols apply to assembler code. It is necessary to emit
242 duplicate line symbols when a compiler asks for them, because GDB
243 uses them to determine the end of the prologue. */
244 if (debug_type
== DEBUG_DWARF2
245 && line
== loc
->line
&& filenum
== loc
->filenum
)
249 filenum
= loc
->filenum
;
251 e
= (struct line_entry
*) xmalloc (sizeof (*e
));
257 ss
= get_line_subseg (now_seg
, now_subseg
);
259 ss
->ptail
= &e
->next
;
264 struct dwarf2_line_info
*line
;
266 if (debug_type
== DEBUG_DWARF2
)
269 as_where (&filename
, &line
->line
);
270 line
->filenum
= get_filenum (filename
);
272 line
->flags
= DWARF2_FLAG_BEGIN_STMT
;
278 /* Called for each machine instruction, or relatively atomic group of
279 machine instructions (ie built-in macro). The instruction or group
280 is SIZE bytes in length. If dwarf2 line number generation is called
281 for, emit a line statement appropriately. */
284 dwarf2_emit_insn (size
)
287 struct dwarf2_line_info loc
;
289 if (debug_type
!= DEBUG_DWARF2
&& ! loc_directive_seen
)
291 loc_directive_seen
= false;
294 dwarf2_gen_line_info (frag_now_fix () - size
, &loc
);
297 /* Get a .debug_line file number for FILENAME. */
300 get_filenum (filename
)
301 const char *filename
;
303 static unsigned int last_used
;
307 if (strcmp (filename
, files
[last_used
].filename
) == 0)
310 for (i
= 1; i
< files_in_use
; ++i
)
311 if (strcmp (filename
, files
[i
].filename
) == 0)
314 if (i
>= files_allocated
)
316 unsigned int old
= files_allocated
;
318 files_allocated
= i
+ 32;
319 files
= (struct file_entry
*)
320 xrealloc (files
, (i
+ 32) * sizeof (struct file_entry
));
322 memset (files
+ old
, 0, (i
+ 32 - old
) * sizeof (struct file_entry
));
325 files
[i
].filename
= xstrdup (filename
);
327 files_in_use
= i
+ 1;
333 /* Handle the .file directive. */
336 dwarf2_directive_file (dummy
)
337 int dummy ATTRIBUTE_UNUSED
;
343 /* Continue to accept a bare string and pass it off. */
345 if (*input_line_pointer
== '"')
351 num
= get_absolute_expression ();
352 filename
= demand_copy_C_string (&filename_len
);
353 demand_empty_rest_of_line ();
357 as_bad (_("file number less than one"));
361 if (num
< (int) files_in_use
&& files
[num
].filename
!= 0)
363 as_bad (_("file number %ld already allocated"), (long) num
);
367 if (num
>= (int) files_allocated
)
369 unsigned int old
= files_allocated
;
371 files_allocated
= num
+ 16;
372 files
= (struct file_entry
*)
373 xrealloc (files
, (num
+ 16) * sizeof (struct file_entry
));
375 /* Zero the new memory. */
376 memset (files
+ old
, 0, (num
+ 16 - old
) * sizeof (struct file_entry
));
379 files
[num
].filename
= filename
;
381 files_in_use
= num
+ 1;
385 dwarf2_directive_loc (dummy
)
386 int dummy ATTRIBUTE_UNUSED
;
388 offsetT filenum
, line
, column
;
390 filenum
= get_absolute_expression ();
392 line
= get_absolute_expression ();
394 column
= get_absolute_expression ();
395 demand_empty_rest_of_line ();
399 as_bad (_("file number less than one"));
402 if (filenum
>= (int) files_in_use
|| files
[filenum
].filename
== 0)
404 as_bad (_("unassigned file number %ld"), (long) filenum
);
408 current
.filenum
= filenum
;
410 current
.column
= column
;
411 current
.flags
= DWARF2_FLAG_BEGIN_STMT
;
413 loc_directive_seen
= true;
417 listing_source_line (line
);
422 first_frag_for_seg (seg
)
425 frchainS
*f
, *first
= NULL
;
427 for (f
= frchain_root
; f
; f
= f
->frch_next
)
428 if (f
->frch_seg
== seg
429 && (! first
|| first
->frch_subseg
> f
->frch_subseg
))
432 return first
? first
->frch_root
: NULL
;
436 last_frag_for_seg (seg
)
439 frchainS
*f
, *last
= NULL
;
441 for (f
= frchain_root
; f
; f
= f
->frch_next
)
442 if (f
->frch_seg
== seg
443 && (! last
|| last
->frch_subseg
< f
->frch_subseg
))
446 return last
? last
->frch_last
: NULL
;
449 /* Emit a single byte into the current segment. */
455 FRAG_APPEND_1_CHAR (byte
);
458 /* Emit a statement program opcode into the current segment. */
467 /* Emit a two-byte word into the current segment. */
473 md_number_to_chars (frag_more (2), data
, 2);
476 /* Emit a four byte word into the current segment. */
482 md_number_to_chars (frag_more (4), data
, 4);
485 /* Emit an unsigned "little-endian base 128" number. */
491 output_leb128 (frag_more (sizeof_leb128 (value
, 0)), value
, 0);
494 /* Emit a tuple for .debug_abbrev. */
497 out_abbrev (name
, form
)
504 /* Create a new fake symbol whose value is the current position. */
509 return symbol_new (fake_label_name
, now_seg
, frag_now_fix (), frag_now
);
512 /* Set the value of SYM to the current position in the current segment. */
515 set_symbol_value_now (sym
)
518 S_SET_SEGMENT (sym
, now_seg
);
519 S_SET_VALUE (sym
, frag_now_fix ());
520 symbol_set_frag (sym
, frag_now
);
523 /* Get the size of a fragment. */
534 /* If a fragment is the last in the chain, special measures must be
535 taken to find its size before relaxation, since it may be pending
536 on some subsegment chain. */
537 for (fr
= frchain_root
; fr
; fr
= fr
->frch_next
)
538 if (fr
->frch_last
== frag
)
540 long align_mask
= -1 << get_recorded_alignment (fr
->frch_seg
);
541 return (((char *) obstack_next_free (&fr
->frch_obstack
)
542 - frag
->fr_literal
) + ~align_mask
) & align_mask
;
548 /* Set an absolute address (may result in a relocation entry). */
551 out_set_addr (seg
, frag
, ofs
)
559 sym
= symbol_new (fake_label_name
, seg
, ofs
, frag
);
561 out_opcode (DW_LNS_extended_op
);
562 out_uleb128 (sizeof_address
+ 1);
564 out_opcode (DW_LNE_set_address
);
565 expr
.X_op
= O_symbol
;
566 expr
.X_add_symbol
= sym
;
567 expr
.X_add_number
= 0;
568 emit_expr (&expr
, sizeof_address
);
571 /* Encode a pair of line and address skips as efficiently as possible.
572 Note that the line skip is signed, whereas the address skip is unsigned.
574 The following two routines *must* be kept in sync. This is
575 enforced by making emit_inc_line_addr abort if we do not emit
576 exactly the expected number of bytes. */
579 size_inc_line_addr (line_delta
, addr_delta
)
583 unsigned int tmp
, opcode
;
586 /* Scale the address delta by the minimum instruction length. */
587 #if DWARF2_LINE_MIN_INSN_LENGTH > 1
588 assert (addr_delta
% DWARF2_LINE_MIN_INSN_LENGTH
== 0);
589 addr_delta
/= DWARF2_LINE_MIN_INSN_LENGTH
;
592 /* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
593 We cannot use special opcodes here, since we want the end_sequence
594 to emit the matrix entry. */
595 if (line_delta
== INT_MAX
)
597 if (addr_delta
== MAX_SPECIAL_ADDR_DELTA
)
600 len
= 1 + sizeof_leb128 (addr_delta
, 0);
604 /* Bias the line delta by the base. */
605 tmp
= line_delta
- DWARF2_LINE_BASE
;
607 /* If the line increment is out of range of a special opcode, we
608 must encode it with DW_LNS_advance_line. */
609 if (tmp
>= DWARF2_LINE_RANGE
)
611 len
= 1 + sizeof_leb128 (line_delta
, 1);
613 tmp
= 0 - DWARF2_LINE_BASE
;
616 /* Bias the opcode by the special opcode base. */
617 tmp
+= DWARF2_LINE_OPCODE_BASE
;
619 /* Avoid overflow when addr_delta is large. */
620 if (addr_delta
< 256 + MAX_SPECIAL_ADDR_DELTA
)
622 /* Try using a special opcode. */
623 opcode
= tmp
+ addr_delta
* DWARF2_LINE_RANGE
;
627 /* Try using DW_LNS_const_add_pc followed by special op. */
628 opcode
= tmp
+ (addr_delta
- MAX_SPECIAL_ADDR_DELTA
) * DWARF2_LINE_RANGE
;
633 /* Otherwise use DW_LNS_advance_pc. */
634 len
+= 1 + sizeof_leb128 (addr_delta
, 0);
636 /* DW_LNS_copy or special opcode. */
643 emit_inc_line_addr (line_delta
, addr_delta
, p
, len
)
649 unsigned int tmp
, opcode
;
653 #if DWARF2_LINE_MIN_INSN_LENGTH > 1
654 /* Scale the address delta by the minimum instruction length. */
655 assert (addr_delta
% DWARF2_LINE_MIN_INSN_LENGTH
== 0);
656 addr_delta
/= DWARF2_LINE_MIN_INSN_LENGTH
;
658 /* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
659 We cannot use special opcodes here, since we want the end_sequence
660 to emit the matrix entry. */
661 if (line_delta
== INT_MAX
)
663 if (addr_delta
== MAX_SPECIAL_ADDR_DELTA
)
664 *p
++ = DW_LNS_const_add_pc
;
667 *p
++ = DW_LNS_advance_pc
;
668 p
+= output_leb128 (p
, addr_delta
, 0);
671 *p
++ = DW_LNS_extended_op
;
673 *p
++ = DW_LNE_end_sequence
;
677 /* Bias the line delta by the base. */
678 tmp
= line_delta
- DWARF2_LINE_BASE
;
680 /* If the line increment is out of range of a special opcode, we
681 must encode it with DW_LNS_advance_line. */
682 if (tmp
>= DWARF2_LINE_RANGE
)
684 *p
++ = DW_LNS_advance_line
;
685 p
+= output_leb128 (p
, line_delta
, 1);
687 /* Prettier, I think, to use DW_LNS_copy instead of a
688 "line +0, addr +0" special opcode. */
696 tmp
= 0 - DWARF2_LINE_BASE
;
700 /* Bias the opcode by the special opcode base. */
701 tmp
+= DWARF2_LINE_OPCODE_BASE
;
703 /* Avoid overflow when addr_delta is large. */
704 if (addr_delta
< 256 + MAX_SPECIAL_ADDR_DELTA
)
706 /* Try using a special opcode. */
707 opcode
= tmp
+ addr_delta
* DWARF2_LINE_RANGE
;
714 /* Try using DW_LNS_const_add_pc followed by special op. */
715 opcode
= tmp
+ (addr_delta
- MAX_SPECIAL_ADDR_DELTA
) * DWARF2_LINE_RANGE
;
718 *p
++ = DW_LNS_const_add_pc
;
724 /* Otherwise use DW_LNS_advance_pc. */
725 *p
++ = DW_LNS_advance_pc
;
726 p
+= output_leb128 (p
, addr_delta
, 0);
737 /* Handy routine to combine calls to the above two routines. */
740 out_inc_line_addr (line_delta
, addr_delta
)
744 int len
= size_inc_line_addr (line_delta
, addr_delta
);
745 emit_inc_line_addr (line_delta
, addr_delta
, frag_more (len
), len
);
748 /* Generate a variant frag that we can use to relax address/line
749 increments between fragments of the target segment. */
752 relax_inc_line_addr (line_delta
, seg
, to_frag
, to_ofs
, from_frag
, from_ofs
)
755 fragS
*to_frag
, *from_frag
;
756 addressT to_ofs
, from_ofs
;
758 symbolS
*to_sym
, *from_sym
;
762 to_sym
= symbol_new (fake_label_name
, seg
, to_ofs
, to_frag
);
763 from_sym
= symbol_new (fake_label_name
, seg
, from_ofs
, from_frag
);
765 expr
.X_op
= O_subtract
;
766 expr
.X_add_symbol
= to_sym
;
767 expr
.X_op_symbol
= from_sym
;
768 expr
.X_add_number
= 0;
770 /* The maximum size of the frag is the line delta with a maximum
771 sized address delta. */
772 max_chars
= size_inc_line_addr (line_delta
, -DWARF2_LINE_MIN_INSN_LENGTH
);
774 frag_var (rs_dwarf2dbg
, max_chars
, max_chars
, 1,
775 make_expr_symbol (&expr
), line_delta
, NULL
);
778 /* The function estimates the size of a rs_dwarf2dbg variant frag
779 based on the current values of the symbols. It is called before
780 the relaxation loop. We set fr_subtype to the expected length. */
783 dwarf2dbg_estimate_size_before_relax (frag
)
789 addr_delta
= resolve_symbol_value (frag
->fr_symbol
);
790 size
= size_inc_line_addr (frag
->fr_offset
, addr_delta
);
792 frag
->fr_subtype
= size
;
797 /* This function relaxes a rs_dwarf2dbg variant frag based on the
798 current values of the symbols. fr_subtype is the current length
799 of the frag. This returns the change in frag length. */
802 dwarf2dbg_relax_frag (frag
)
805 int old_size
, new_size
;
807 old_size
= frag
->fr_subtype
;
808 new_size
= dwarf2dbg_estimate_size_before_relax (frag
);
810 return new_size
- old_size
;
813 /* This function converts a rs_dwarf2dbg variant frag into a normal
814 fill frag. This is called after all relaxation has been done.
815 fr_subtype will be the desired length of the frag. */
818 dwarf2dbg_convert_frag (frag
)
823 addr_diff
= resolve_symbol_value (frag
->fr_symbol
);
825 /* fr_var carries the max_chars that we created the fragment with.
826 fr_subtype carries the current expected length. We must, of
827 course, have allocated enough memory earlier. */
828 assert (frag
->fr_var
>= (int) frag
->fr_subtype
);
830 emit_inc_line_addr (frag
->fr_offset
, addr_diff
,
831 frag
->fr_literal
+ frag
->fr_fix
, frag
->fr_subtype
);
833 frag
->fr_fix
+= frag
->fr_subtype
;
834 frag
->fr_type
= rs_fill
;
839 /* Generate .debug_line content for the chain of line number entries
840 beginning at E, for segment SEG. */
843 process_entries (seg
, e
)
845 struct line_entry
*e
;
847 unsigned filenum
= 1;
850 unsigned flags
= DWARF2_LINE_DEFAULT_IS_STMT
? DWARF2_FLAG_BEGIN_STMT
: 0;
853 addressT frag_ofs
= 0;
854 addressT last_frag_ofs
;
855 struct line_entry
*next
;
861 if (filenum
!= e
->loc
.filenum
)
863 filenum
= e
->loc
.filenum
;
864 out_opcode (DW_LNS_set_file
);
865 out_uleb128 (filenum
);
869 if (column
!= e
->loc
.column
)
871 column
= e
->loc
.column
;
872 out_opcode (DW_LNS_set_column
);
873 out_uleb128 (column
);
877 if ((e
->loc
.flags
^ flags
) & DWARF2_FLAG_BEGIN_STMT
)
879 flags
= e
->loc
.flags
;
880 out_opcode (DW_LNS_negate_stmt
);
884 if (e
->loc
.flags
& DWARF2_FLAG_BEGIN_BLOCK
)
886 out_opcode (DW_LNS_set_basic_block
);
890 /* Don't try to optimize away redundant entries; gdb wants two
891 entries for a function where the code starts on the same line as
892 the {, and there's no way to identify that case here. Trust gcc
893 to optimize appropriately. */
894 if (1 /* line != e->loc.line || changed */)
896 int line_delta
= e
->loc
.line
- line
;
899 out_set_addr (seg
, e
->frag
, e
->frag_ofs
);
900 out_inc_line_addr (line_delta
, 0);
902 else if (frag
== e
->frag
)
903 out_inc_line_addr (line_delta
, e
->frag_ofs
- frag_ofs
);
905 relax_inc_line_addr (line_delta
, seg
, e
->frag
, e
->frag_ofs
,
909 frag_ofs
= e
->frag_ofs
;
912 else if (frag
== NULL
)
914 out_set_addr (seg
, e
->frag
, e
->frag_ofs
);
916 frag_ofs
= e
->frag_ofs
;
924 /* Emit a DW_LNE_end_sequence for the end of the section. */
925 last_frag
= last_frag_for_seg (seg
);
926 last_frag_ofs
= get_frag_fix (last_frag
);
927 if (frag
== last_frag
)
928 out_inc_line_addr (INT_MAX
, last_frag_ofs
- frag_ofs
);
930 relax_inc_line_addr (INT_MAX
, seg
, last_frag
, last_frag_ofs
,
934 /* Emit the directory and file tables for .debug_line. */
943 /* Terminate directory list. */
946 for (i
= 1; i
< files_in_use
; ++i
)
948 if (files
[i
].filename
== NULL
)
950 as_bad (_("unassigned file number %ld"), (long) i
);
954 size
= strlen (files
[i
].filename
) + 1;
955 cp
= frag_more (size
);
956 memcpy (cp
, files
[i
].filename
, size
);
958 out_uleb128 (files
[i
].dir
); /* directory number */
959 out_uleb128 (0); /* last modification timestamp */
960 out_uleb128 (0); /* filesize */
963 /* Terminate filename list. */
967 /* Emit the collected .debug_line data. */
970 out_debug_line (line_seg
)
975 symbolS
*prologue_end
;
979 subseg_set (line_seg
, 0);
981 line_start
= symbol_new_now ();
982 prologue_end
= symbol_make (fake_label_name
);
983 line_end
= symbol_make (fake_label_name
);
985 /* Total length of the information for this compilation unit. */
986 expr
.X_op
= O_subtract
;
987 expr
.X_add_symbol
= line_end
;
988 expr
.X_op_symbol
= line_start
;
989 expr
.X_add_number
= -4;
990 emit_expr (&expr
, 4);
995 /* Length of the prologue following this length. */
996 expr
.X_op
= O_subtract
;
997 expr
.X_add_symbol
= prologue_end
;
998 expr
.X_op_symbol
= line_start
;
999 expr
.X_add_number
= - (4 + 2 + 4);
1000 emit_expr (&expr
, 4);
1002 /* Parameters of the state machine. */
1003 out_byte (DWARF2_LINE_MIN_INSN_LENGTH
);
1004 out_byte (DWARF2_LINE_DEFAULT_IS_STMT
);
1005 out_byte (DWARF2_LINE_BASE
);
1006 out_byte (DWARF2_LINE_RANGE
);
1007 out_byte (DWARF2_LINE_OPCODE_BASE
);
1009 /* Standard opcode lengths. */
1010 out_byte (0); /* DW_LNS_copy */
1011 out_byte (1); /* DW_LNS_advance_pc */
1012 out_byte (1); /* DW_LNS_advance_line */
1013 out_byte (1); /* DW_LNS_set_file */
1014 out_byte (1); /* DW_LNS_set_column */
1015 out_byte (0); /* DW_LNS_negate_stmt */
1016 out_byte (0); /* DW_LNS_set_basic_block */
1017 out_byte (0); /* DW_LNS_const_add_pc */
1018 out_byte (1); /* DW_LNS_fixed_advance_pc */
1022 set_symbol_value_now (prologue_end
);
1024 /* For each section, emit a statement program. */
1025 for (s
= all_segs
; s
; s
= s
->next
)
1026 process_entries (s
->seg
, s
->head
->head
);
1028 set_symbol_value_now (line_end
);
1031 /* Emit data for .debug_aranges. */
1034 out_debug_aranges (aranges_seg
, info_seg
)
1038 unsigned int addr_size
= sizeof_address
;
1039 addressT size
, skip
;
1044 size
= 4 + 2 + 4 + 1 + 1;
1046 skip
= 2 * addr_size
- (size
& (2 * addr_size
- 1));
1047 if (skip
== 2 * addr_size
)
1051 for (s
= all_segs
; s
; s
= s
->next
)
1052 size
+= 2 * addr_size
;
1054 size
+= 2 * addr_size
;
1056 subseg_set (aranges_seg
, 0);
1058 /* Length of the compilation unit. */
1059 out_four (size
- 4);
1064 /* Offset to .debug_info. */
1065 expr
.X_op
= O_symbol
;
1066 expr
.X_add_symbol
= section_symbol (info_seg
);
1067 expr
.X_add_number
= 0;
1068 emit_expr (&expr
, 4);
1070 /* Size of an address (offset portion). */
1071 out_byte (addr_size
);
1073 /* Size of a segment descriptor. */
1076 /* Align the header. */
1078 frag_align (ffs (2 * addr_size
) - 1, 0, 0);
1080 for (s
= all_segs
; s
; s
= s
->next
)
1085 frag
= first_frag_for_seg (s
->seg
);
1086 beg
= symbol_new (fake_label_name
, s
->seg
, 0, frag
);
1087 s
->text_start
= beg
;
1089 frag
= last_frag_for_seg (s
->seg
);
1090 end
= symbol_new (fake_label_name
, s
->seg
, get_frag_fix (frag
), frag
);
1093 expr
.X_op
= O_symbol
;
1094 expr
.X_add_symbol
= beg
;
1095 expr
.X_add_number
= 0;
1096 emit_expr (&expr
, addr_size
);
1098 expr
.X_op
= O_subtract
;
1099 expr
.X_add_symbol
= end
;
1100 expr
.X_op_symbol
= beg
;
1101 expr
.X_add_number
= 0;
1102 emit_expr (&expr
, addr_size
);
1105 p
= frag_more (2 * addr_size
);
1106 md_number_to_chars (p
, 0, addr_size
);
1107 md_number_to_chars (p
+ addr_size
, 0, addr_size
);
1110 /* Emit data for .debug_abbrev. Note that this must be kept in
1111 sync with out_debug_info below. */
1114 out_debug_abbrev (abbrev_seg
)
1117 subseg_set (abbrev_seg
, 0);
1120 out_uleb128 (DW_TAG_compile_unit
);
1121 out_byte (DW_CHILDREN_no
);
1122 out_abbrev (DW_AT_stmt_list
, DW_FORM_data4
);
1123 if (all_segs
->next
== NULL
)
1125 out_abbrev (DW_AT_low_pc
, DW_FORM_addr
);
1126 out_abbrev (DW_AT_high_pc
, DW_FORM_addr
);
1128 out_abbrev (DW_AT_comp_dir
, DW_FORM_string
);
1129 out_abbrev (DW_AT_producer
, DW_FORM_string
);
1130 out_abbrev (DW_AT_language
, DW_FORM_data2
);
1133 /* Terminate the abbreviations for this compilation unit. */
1137 /* Emit a description of this compilation unit for .debug_info. */
1140 out_debug_info (info_seg
, abbrev_seg
, line_seg
)
1148 symbolS
*info_start
;
1153 subseg_set (info_seg
, 0);
1155 info_start
= symbol_new_now ();
1156 info_end
= symbol_make (fake_label_name
);
1158 /* Compilation Unit length. */
1159 expr
.X_op
= O_subtract
;
1160 expr
.X_add_symbol
= info_end
;
1161 expr
.X_op_symbol
= info_start
;
1162 expr
.X_add_number
= -4;
1163 emit_expr (&expr
, 4);
1165 /* DWARF version. */
1168 /* .debug_abbrev offset */
1169 expr
.X_op
= O_symbol
;
1170 expr
.X_add_symbol
= section_symbol (abbrev_seg
);
1171 expr
.X_add_number
= 0;
1172 emit_expr (&expr
, 4);
1174 /* Target address size. */
1175 out_byte (sizeof_address
);
1177 /* DW_TAG_compile_unit DIE abbrev */
1180 /* DW_AT_stmt_list */
1181 expr
.X_op
= O_symbol
;
1182 expr
.X_add_symbol
= section_symbol (line_seg
);
1183 expr
.X_add_number
= 0;
1184 emit_expr (&expr
, 4);
1186 /* These two attributes may only be emitted if all of the code is
1187 contiguous. Multiple sections are not that. */
1188 if (all_segs
->next
== NULL
)
1191 expr
.X_op
= O_symbol
;
1192 expr
.X_add_symbol
= all_segs
->text_start
;
1193 expr
.X_add_number
= 0;
1194 emit_expr (&expr
, sizeof_address
);
1197 expr
.X_op
= O_symbol
;
1198 expr
.X_add_symbol
= all_segs
->text_end
;
1199 expr
.X_add_number
= 0;
1200 emit_expr (&expr
, sizeof_address
);
1203 /* DW_AT_comp_dir */
1204 comp_dir
= getpwd ();
1205 len
= strlen (comp_dir
) + 1;
1206 p
= frag_more (len
);
1207 memcpy (p
, comp_dir
, len
);
1209 /* DW_AT_producer */
1210 sprintf (producer
, "GNU AS %s", VERSION
);
1211 len
= strlen (producer
) + 1;
1212 p
= frag_more (len
);
1213 memcpy (p
, producer
, len
);
1215 /* DW_AT_language. Yes, this is probably not really MIPS, but the
1216 dwarf2 draft has no standard code for assembler. */
1217 out_two (DW_LANG_Mips_Assembler
);
1219 set_symbol_value_now (info_end
);
1228 /* If no debug information was recorded, nothing to do. */
1229 if (all_segs
== NULL
&& files_in_use
<= 1)
1232 /* Calculate the size of an address for the target machine. */
1233 sizeof_address
= bfd_arch_bits_per_address (stdoutput
) / 8;
1235 /* Create and switch to the line number section. */
1236 line_seg
= subseg_new (".debug_line", 0);
1237 bfd_set_section_flags (stdoutput
, line_seg
, SEC_READONLY
);
1239 /* For each subsection, chain the debug entries together. */
1240 for (s
= all_segs
; s
; s
= s
->next
)
1242 struct line_subseg
*ss
= s
->head
;
1243 struct line_entry
**ptail
= ss
->ptail
;
1245 while ((ss
= ss
->next
) != NULL
)
1252 out_debug_line (line_seg
);
1254 /* If this is assembler generated line info, we need .debug_info
1255 and .debug_abbrev sections as well. */
1256 if (all_segs
!= NULL
&& debug_type
== DEBUG_DWARF2
)
1262 info_seg
= subseg_new (".debug_info", 0);
1263 abbrev_seg
= subseg_new (".debug_abbrev", 0);
1264 aranges_seg
= subseg_new (".debug_aranges", 0);
1266 bfd_set_section_flags (stdoutput
, info_seg
, SEC_READONLY
);
1267 bfd_set_section_flags (stdoutput
, abbrev_seg
, SEC_READONLY
);
1268 bfd_set_section_flags (stdoutput
, aranges_seg
, SEC_READONLY
);
1270 record_alignment (aranges_seg
, ffs (2 * sizeof_address
) - 1);
1272 out_debug_aranges (aranges_seg
, info_seg
);
1273 out_debug_abbrev (abbrev_seg
);
1274 out_debug_info (info_seg
, abbrev_seg
, line_seg
);
1285 dwarf2dbg_estimate_size_before_relax (frag
)
1286 fragS
*frag ATTRIBUTE_UNUSED
;
1288 as_fatal (_("dwarf2 is not supported for this object file format"));
1293 dwarf2dbg_relax_frag (frag
)
1294 fragS
*frag ATTRIBUTE_UNUSED
;
1296 as_fatal (_("dwarf2 is not supported for this object file format"));
1301 dwarf2dbg_convert_frag (frag
)
1302 fragS
*frag ATTRIBUTE_UNUSED
;
1304 as_fatal (_("dwarf2 is not supported for this object file format"));
1308 dwarf2_emit_insn (size
)
1309 int size ATTRIBUTE_UNUSED
;
1314 dwarf2_directive_file (dummy
)
1315 int dummy ATTRIBUTE_UNUSED
;
1321 dwarf2_directive_loc (dummy
)
1322 int dummy ATTRIBUTE_UNUSED
;
1324 as_fatal (_("dwarf2 is not supported for this object file format"));
1326 #endif /* BFD_ASSEMBLER */