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[binutils.git] / gas / dw2gencfi.c
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1 /* dw2gencfi.c - Support for generating Dwarf2 CFI information.
2 Copyright 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
3 Contributed by Michal Ludvig <mludvig@suse.cz>
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 3, or (at your option)
10 any later version.
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, 51 Franklin Street - Fifth Floor, Boston, MA
20 02110-1301, USA. */
22 #include "as.h"
23 #include "dw2gencfi.h"
24 #include "subsegs.h"
26 #ifdef TARGET_USE_CFIPOP
28 /* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field
29 of the CIE. Default to 1 if not otherwise specified. */
30 #ifndef DWARF2_LINE_MIN_INSN_LENGTH
31 # define DWARF2_LINE_MIN_INSN_LENGTH 1
32 #endif
34 #ifndef EH_FRAME_ALIGNMENT
35 # define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2)
36 #endif
38 #ifndef tc_cfi_frame_initial_instructions
39 # define tc_cfi_frame_initial_instructions() ((void)0)
40 #endif
43 struct cfi_insn_data
45 struct cfi_insn_data *next;
46 int insn;
47 union {
48 struct {
49 unsigned reg;
50 offsetT offset;
51 } ri;
53 struct {
54 unsigned reg1;
55 unsigned reg2;
56 } rr;
58 unsigned r;
59 offsetT i;
61 struct {
62 symbolS *lab1;
63 symbolS *lab2;
64 } ll;
66 struct cfi_escape_data {
67 struct cfi_escape_data *next;
68 expressionS exp;
69 } *esc;
70 } u;
73 struct fde_entry
75 struct fde_entry *next;
76 symbolS *start_address;
77 symbolS *end_address;
78 struct cfi_insn_data *data;
79 struct cfi_insn_data **last;
80 unsigned char per_encoding;
81 unsigned char lsda_encoding;
82 expressionS personality;
83 expressionS lsda;
84 unsigned int return_column;
85 unsigned int signal_frame;
88 struct cie_entry
90 struct cie_entry *next;
91 symbolS *start_address;
92 unsigned int return_column;
93 unsigned int signal_frame;
94 unsigned char per_encoding;
95 unsigned char lsda_encoding;
96 expressionS personality;
97 struct cfi_insn_data *first, *last;
101 /* List of FDE entries. */
102 static struct fde_entry *all_fde_data;
103 static struct fde_entry **last_fde_data = &all_fde_data;
105 /* List of CIEs so that they could be reused. */
106 static struct cie_entry *cie_root;
108 /* Stack of old CFI data, for save/restore. */
109 struct cfa_save_data
111 struct cfa_save_data *next;
112 offsetT cfa_offset;
115 /* Current open FDE entry. */
116 struct frch_cfi_data
118 struct fde_entry *cur_fde_data;
119 symbolS *last_address;
120 offsetT cur_cfa_offset;
121 struct cfa_save_data *cfa_save_stack;
124 /* Construct a new FDE structure and add it to the end of the fde list. */
126 static struct fde_entry *
127 alloc_fde_entry (void)
129 struct fde_entry *fde = xcalloc (1, sizeof (struct fde_entry));
131 frchain_now->frch_cfi_data = xcalloc (1, sizeof (struct frch_cfi_data));
132 frchain_now->frch_cfi_data->cur_fde_data = fde;
133 *last_fde_data = fde;
134 last_fde_data = &fde->next;
136 fde->last = &fde->data;
137 fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN;
138 fde->per_encoding = DW_EH_PE_omit;
139 fde->lsda_encoding = DW_EH_PE_omit;
141 return fde;
144 /* The following functions are available for a backend to construct its
145 own unwind information, usually from legacy unwind directives. */
147 /* Construct a new INSN structure and add it to the end of the insn list
148 for the currently active FDE. */
150 static struct cfi_insn_data *
151 alloc_cfi_insn_data (void)
153 struct cfi_insn_data *insn = xcalloc (1, sizeof (struct cfi_insn_data));
154 struct fde_entry *cur_fde_data = frchain_now->frch_cfi_data->cur_fde_data;
156 *cur_fde_data->last = insn;
157 cur_fde_data->last = &insn->next;
159 return insn;
162 /* Construct a new FDE structure that begins at LABEL. */
164 void
165 cfi_new_fde (symbolS *label)
167 struct fde_entry *fde = alloc_fde_entry ();
168 fde->start_address = label;
169 frchain_now->frch_cfi_data->last_address = label;
172 /* End the currently open FDE. */
174 void
175 cfi_end_fde (symbolS *label)
177 frchain_now->frch_cfi_data->cur_fde_data->end_address = label;
178 free (frchain_now->frch_cfi_data);
179 frchain_now->frch_cfi_data = NULL;
182 /* Set the return column for the current FDE. */
184 void
185 cfi_set_return_column (unsigned regno)
187 frchain_now->frch_cfi_data->cur_fde_data->return_column = regno;
190 /* Universal functions to store new instructions. */
192 static void
193 cfi_add_CFA_insn(int insn)
195 struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
197 insn_ptr->insn = insn;
200 static void
201 cfi_add_CFA_insn_reg (int insn, unsigned regno)
203 struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
205 insn_ptr->insn = insn;
206 insn_ptr->u.r = regno;
209 static void
210 cfi_add_CFA_insn_offset (int insn, offsetT offset)
212 struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
214 insn_ptr->insn = insn;
215 insn_ptr->u.i = offset;
218 static void
219 cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2)
221 struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
223 insn_ptr->insn = insn;
224 insn_ptr->u.rr.reg1 = reg1;
225 insn_ptr->u.rr.reg2 = reg2;
228 static void
229 cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset)
231 struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
233 insn_ptr->insn = insn;
234 insn_ptr->u.ri.reg = regno;
235 insn_ptr->u.ri.offset = offset;
238 /* Add a CFI insn to advance the PC from the last address to LABEL. */
240 void
241 cfi_add_advance_loc (symbolS *label)
243 struct cfi_insn_data *insn = alloc_cfi_insn_data ();
245 insn->insn = DW_CFA_advance_loc;
246 insn->u.ll.lab1 = frchain_now->frch_cfi_data->last_address;
247 insn->u.ll.lab2 = label;
249 frchain_now->frch_cfi_data->last_address = label;
252 /* Add a DW_CFA_offset record to the CFI data. */
254 void
255 cfi_add_CFA_offset (unsigned regno, offsetT offset)
257 unsigned int abs_data_align;
259 assert (DWARF2_CIE_DATA_ALIGNMENT != 0);
260 cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset);
262 abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0
263 ? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT);
264 if (offset % abs_data_align)
265 as_bad (_("register save offset not a multiple of %u"), abs_data_align);
268 /* Add a DW_CFA_def_cfa record to the CFI data. */
270 void
271 cfi_add_CFA_def_cfa (unsigned regno, offsetT offset)
273 cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset);
274 frchain_now->frch_cfi_data->cur_cfa_offset = offset;
277 /* Add a DW_CFA_register record to the CFI data. */
279 void
280 cfi_add_CFA_register (unsigned reg1, unsigned reg2)
282 cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2);
285 /* Add a DW_CFA_def_cfa_register record to the CFI data. */
287 void
288 cfi_add_CFA_def_cfa_register (unsigned regno)
290 cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno);
293 /* Add a DW_CFA_def_cfa_offset record to the CFI data. */
295 void
296 cfi_add_CFA_def_cfa_offset (offsetT offset)
298 cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset);
299 frchain_now->frch_cfi_data->cur_cfa_offset = offset;
302 void
303 cfi_add_CFA_restore (unsigned regno)
305 cfi_add_CFA_insn_reg (DW_CFA_restore, regno);
308 void
309 cfi_add_CFA_undefined (unsigned regno)
311 cfi_add_CFA_insn_reg (DW_CFA_undefined, regno);
314 void
315 cfi_add_CFA_same_value (unsigned regno)
317 cfi_add_CFA_insn_reg (DW_CFA_same_value, regno);
320 void
321 cfi_add_CFA_remember_state (void)
323 struct cfa_save_data *p;
325 cfi_add_CFA_insn (DW_CFA_remember_state);
327 p = xmalloc (sizeof (*p));
328 p->cfa_offset = frchain_now->frch_cfi_data->cur_cfa_offset;
329 p->next = frchain_now->frch_cfi_data->cfa_save_stack;
330 frchain_now->frch_cfi_data->cfa_save_stack = p;
333 void
334 cfi_add_CFA_restore_state (void)
336 struct cfa_save_data *p;
338 cfi_add_CFA_insn (DW_CFA_restore_state);
340 p = frchain_now->frch_cfi_data->cfa_save_stack;
341 if (p)
343 frchain_now->frch_cfi_data->cur_cfa_offset = p->cfa_offset;
344 frchain_now->frch_cfi_data->cfa_save_stack = p->next;
345 free (p);
347 else
348 as_bad (_("CFI state restore without previous remember"));
352 /* Parse CFI assembler directives. */
354 static void dot_cfi (int);
355 static void dot_cfi_escape (int);
356 static void dot_cfi_startproc (int);
357 static void dot_cfi_endproc (int);
358 static void dot_cfi_personality (int);
359 static void dot_cfi_lsda (int);
361 /* Fake CFI type; outside the byte range of any real CFI insn. */
362 #define CFI_adjust_cfa_offset 0x100
363 #define CFI_return_column 0x101
364 #define CFI_rel_offset 0x102
365 #define CFI_escape 0x103
366 #define CFI_signal_frame 0x104
368 const pseudo_typeS cfi_pseudo_table[] =
370 { "cfi_startproc", dot_cfi_startproc, 0 },
371 { "cfi_endproc", dot_cfi_endproc, 0 },
372 { "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa },
373 { "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register },
374 { "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset },
375 { "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset },
376 { "cfi_offset", dot_cfi, DW_CFA_offset },
377 { "cfi_rel_offset", dot_cfi, CFI_rel_offset },
378 { "cfi_register", dot_cfi, DW_CFA_register },
379 { "cfi_return_column", dot_cfi, CFI_return_column },
380 { "cfi_restore", dot_cfi, DW_CFA_restore },
381 { "cfi_undefined", dot_cfi, DW_CFA_undefined },
382 { "cfi_same_value", dot_cfi, DW_CFA_same_value },
383 { "cfi_remember_state", dot_cfi, DW_CFA_remember_state },
384 { "cfi_restore_state", dot_cfi, DW_CFA_restore_state },
385 { "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save },
386 { "cfi_escape", dot_cfi_escape, 0 },
387 { "cfi_signal_frame", dot_cfi, CFI_signal_frame },
388 { "cfi_personality", dot_cfi_personality, 0 },
389 { "cfi_lsda", dot_cfi_lsda, 0 },
390 { NULL, NULL, 0 }
393 static void
394 cfi_parse_separator (void)
396 SKIP_WHITESPACE ();
397 if (*input_line_pointer == ',')
398 input_line_pointer++;
399 else
400 as_bad (_("missing separator"));
403 #ifndef tc_parse_to_dw2regnum
404 static void
405 tc_parse_to_dw2regnum(expressionS *exp)
407 # ifdef tc_regname_to_dw2regnum
408 SKIP_WHITESPACE ();
409 if (is_name_beginner (*input_line_pointer)
410 || (*input_line_pointer == '%'
411 && is_name_beginner (*++input_line_pointer)))
413 char *name, c;
415 name = input_line_pointer;
416 c = get_symbol_end ();
418 exp->X_op = O_constant;
419 exp->X_add_number = tc_regname_to_dw2regnum (name);
421 *input_line_pointer = c;
423 else
424 # endif
425 expression_and_evaluate (exp);
427 #endif
429 static unsigned
430 cfi_parse_reg (void)
432 int regno;
433 expressionS exp;
435 tc_parse_to_dw2regnum (&exp);
436 switch (exp.X_op)
438 case O_register:
439 case O_constant:
440 regno = exp.X_add_number;
441 break;
443 default:
444 regno = -1;
445 break;
448 if (regno < 0)
450 as_bad (_("bad register expression"));
451 regno = 0;
454 return regno;
457 static offsetT
458 cfi_parse_const (void)
460 return get_absolute_expression ();
463 static void
464 dot_cfi (int arg)
466 offsetT offset;
467 unsigned reg1, reg2;
469 if (frchain_now->frch_cfi_data == NULL)
471 as_bad (_("CFI instruction used without previous .cfi_startproc"));
472 ignore_rest_of_line ();
473 return;
476 /* If the last address was not at the current PC, advance to current. */
477 if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now
478 || S_GET_VALUE (frchain_now->frch_cfi_data->last_address)
479 != frag_now_fix ())
480 cfi_add_advance_loc (symbol_temp_new_now ());
482 switch (arg)
484 case DW_CFA_offset:
485 reg1 = cfi_parse_reg ();
486 cfi_parse_separator ();
487 offset = cfi_parse_const ();
488 cfi_add_CFA_offset (reg1, offset);
489 break;
491 case CFI_rel_offset:
492 reg1 = cfi_parse_reg ();
493 cfi_parse_separator ();
494 offset = cfi_parse_const ();
495 cfi_add_CFA_offset (reg1,
496 offset - frchain_now->frch_cfi_data->cur_cfa_offset);
497 break;
499 case DW_CFA_def_cfa:
500 reg1 = cfi_parse_reg ();
501 cfi_parse_separator ();
502 offset = cfi_parse_const ();
503 cfi_add_CFA_def_cfa (reg1, offset);
504 break;
506 case DW_CFA_register:
507 reg1 = cfi_parse_reg ();
508 cfi_parse_separator ();
509 reg2 = cfi_parse_reg ();
510 cfi_add_CFA_register (reg1, reg2);
511 break;
513 case DW_CFA_def_cfa_register:
514 reg1 = cfi_parse_reg ();
515 cfi_add_CFA_def_cfa_register (reg1);
516 break;
518 case DW_CFA_def_cfa_offset:
519 offset = cfi_parse_const ();
520 cfi_add_CFA_def_cfa_offset (offset);
521 break;
523 case CFI_adjust_cfa_offset:
524 offset = cfi_parse_const ();
525 cfi_add_CFA_def_cfa_offset (frchain_now->frch_cfi_data->cur_cfa_offset
526 + offset);
527 break;
529 case DW_CFA_restore:
530 for (;;)
532 reg1 = cfi_parse_reg ();
533 cfi_add_CFA_restore (reg1);
534 SKIP_WHITESPACE ();
535 if (*input_line_pointer != ',')
536 break;
537 ++input_line_pointer;
539 break;
541 case DW_CFA_undefined:
542 for (;;)
544 reg1 = cfi_parse_reg ();
545 cfi_add_CFA_undefined (reg1);
546 SKIP_WHITESPACE ();
547 if (*input_line_pointer != ',')
548 break;
549 ++input_line_pointer;
551 break;
553 case DW_CFA_same_value:
554 reg1 = cfi_parse_reg ();
555 cfi_add_CFA_same_value (reg1);
556 break;
558 case CFI_return_column:
559 reg1 = cfi_parse_reg ();
560 cfi_set_return_column (reg1);
561 break;
563 case DW_CFA_remember_state:
564 cfi_add_CFA_remember_state ();
565 break;
567 case DW_CFA_restore_state:
568 cfi_add_CFA_restore_state ();
569 break;
571 case DW_CFA_GNU_window_save:
572 cfi_add_CFA_insn (DW_CFA_GNU_window_save);
573 break;
575 case CFI_signal_frame:
576 frchain_now->frch_cfi_data->cur_fde_data->signal_frame = 1;
577 break;
579 default:
580 abort ();
583 demand_empty_rest_of_line ();
586 static void
587 dot_cfi_escape (int ignored ATTRIBUTE_UNUSED)
589 struct cfi_escape_data *head, **tail, *e;
590 struct cfi_insn_data *insn;
592 if (frchain_now->frch_cfi_data == NULL)
594 as_bad (_("CFI instruction used without previous .cfi_startproc"));
595 ignore_rest_of_line ();
596 return;
599 /* If the last address was not at the current PC, advance to current. */
600 if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now
601 || S_GET_VALUE (frchain_now->frch_cfi_data->last_address)
602 != frag_now_fix ())
603 cfi_add_advance_loc (symbol_temp_new_now ());
605 tail = &head;
608 e = xmalloc (sizeof (*e));
609 do_parse_cons_expression (&e->exp, 1);
610 *tail = e;
611 tail = &e->next;
613 while (*input_line_pointer++ == ',');
614 *tail = NULL;
616 insn = alloc_cfi_insn_data ();
617 insn->insn = CFI_escape;
618 insn->u.esc = head;
620 --input_line_pointer;
621 demand_empty_rest_of_line ();
624 static void
625 dot_cfi_personality (int ignored ATTRIBUTE_UNUSED)
627 struct fde_entry *fde;
628 offsetT encoding;
630 if (frchain_now->frch_cfi_data == NULL)
632 as_bad (_("CFI instruction used without previous .cfi_startproc"));
633 ignore_rest_of_line ();
634 return;
637 fde = frchain_now->frch_cfi_data->cur_fde_data;
638 encoding = get_absolute_expression ();
639 if (encoding == DW_EH_PE_omit)
641 demand_empty_rest_of_line ();
642 fde->per_encoding = encoding;
643 return;
646 if ((encoding & 0xff) != encoding
647 || ((encoding & 0x70) != 0
648 #if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
649 && (encoding & 0x70) != DW_EH_PE_pcrel
650 #endif
652 /* leb128 can be handled, but does something actually need it? */
653 || (encoding & 7) == DW_EH_PE_uleb128
654 || (encoding & 7) > DW_EH_PE_udata8)
656 as_bad (_("invalid or unsupported encoding in .cfi_personality"));
657 ignore_rest_of_line ();
658 return;
661 if (*input_line_pointer++ != ',')
663 as_bad (_(".cfi_personality requires encoding and symbol arguments"));
664 ignore_rest_of_line ();
665 return;
668 expression_and_evaluate (&fde->personality);
669 switch (fde->personality.X_op)
671 case O_symbol:
672 break;
673 case O_constant:
674 if ((encoding & 0x70) == DW_EH_PE_pcrel)
675 encoding = DW_EH_PE_omit;
676 break;
677 default:
678 encoding = DW_EH_PE_omit;
679 break;
682 fde->per_encoding = encoding;
684 if (encoding == DW_EH_PE_omit)
686 as_bad (_("wrong second argument to .cfi_personality"));
687 ignore_rest_of_line ();
688 return;
691 demand_empty_rest_of_line ();
694 static void
695 dot_cfi_lsda (int ignored ATTRIBUTE_UNUSED)
697 struct fde_entry *fde;
698 offsetT encoding;
700 if (frchain_now->frch_cfi_data == NULL)
702 as_bad (_("CFI instruction used without previous .cfi_startproc"));
703 ignore_rest_of_line ();
704 return;
707 fde = frchain_now->frch_cfi_data->cur_fde_data;
708 encoding = get_absolute_expression ();
709 if (encoding == DW_EH_PE_omit)
711 demand_empty_rest_of_line ();
712 fde->lsda_encoding = encoding;
713 return;
716 if ((encoding & 0xff) != encoding
717 || ((encoding & 0x70) != 0
718 #if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
719 && (encoding & 0x70) != DW_EH_PE_pcrel
720 #endif
722 /* leb128 can be handled, but does something actually need it? */
723 || (encoding & 7) == DW_EH_PE_uleb128
724 || (encoding & 7) > DW_EH_PE_udata8)
726 as_bad (_("invalid or unsupported encoding in .cfi_lsda"));
727 ignore_rest_of_line ();
728 return;
731 if (*input_line_pointer++ != ',')
733 as_bad (_(".cfi_lsda requires encoding and symbol arguments"));
734 ignore_rest_of_line ();
735 return;
738 fde->lsda_encoding = encoding;
740 expression_and_evaluate (&fde->lsda);
741 switch (fde->lsda.X_op)
743 case O_symbol:
744 break;
745 case O_constant:
746 if ((encoding & 0x70) == DW_EH_PE_pcrel)
747 encoding = DW_EH_PE_omit;
748 break;
749 default:
750 encoding = DW_EH_PE_omit;
751 break;
754 fde->lsda_encoding = encoding;
756 if (encoding == DW_EH_PE_omit)
758 as_bad (_("wrong second argument to .cfi_lsda"));
759 ignore_rest_of_line ();
760 return;
763 demand_empty_rest_of_line ();
766 static void
767 dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED)
769 int simple = 0;
771 if (frchain_now->frch_cfi_data != NULL)
773 as_bad (_("previous CFI entry not closed (missing .cfi_endproc)"));
774 ignore_rest_of_line ();
775 return;
778 cfi_new_fde (symbol_temp_new_now ());
780 SKIP_WHITESPACE ();
781 if (is_name_beginner (*input_line_pointer))
783 char *name, c;
785 name = input_line_pointer;
786 c = get_symbol_end ();
788 if (strcmp (name, "simple") == 0)
790 simple = 1;
791 *input_line_pointer = c;
793 else
794 input_line_pointer = name;
796 demand_empty_rest_of_line ();
798 frchain_now->frch_cfi_data->cur_cfa_offset = 0;
799 if (!simple)
800 tc_cfi_frame_initial_instructions ();
803 static void
804 dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED)
806 if (frchain_now->frch_cfi_data == NULL)
808 as_bad (_(".cfi_endproc without corresponding .cfi_startproc"));
809 ignore_rest_of_line ();
810 return;
813 cfi_end_fde (symbol_temp_new_now ());
815 demand_empty_rest_of_line ();
819 /* Emit a single byte into the current segment. */
821 static inline void
822 out_one (int byte)
824 FRAG_APPEND_1_CHAR (byte);
827 /* Emit a two-byte word into the current segment. */
829 static inline void
830 out_two (int data)
832 md_number_to_chars (frag_more (2), data, 2);
835 /* Emit a four byte word into the current segment. */
837 static inline void
838 out_four (int data)
840 md_number_to_chars (frag_more (4), data, 4);
843 /* Emit an unsigned "little-endian base 128" number. */
845 static void
846 out_uleb128 (addressT value)
848 output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
851 /* Emit an unsigned "little-endian base 128" number. */
853 static void
854 out_sleb128 (offsetT value)
856 output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
859 static void
860 output_cfi_insn (struct cfi_insn_data *insn)
862 offsetT offset;
863 unsigned int regno;
865 switch (insn->insn)
867 case DW_CFA_advance_loc:
869 symbolS *from = insn->u.ll.lab1;
870 symbolS *to = insn->u.ll.lab2;
872 if (symbol_get_frag (to) == symbol_get_frag (from))
874 addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from);
875 addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH;
877 if (scaled <= 0x3F)
878 out_one (DW_CFA_advance_loc + scaled);
879 else if (delta <= 0xFF)
881 out_one (DW_CFA_advance_loc1);
882 out_one (delta);
884 else if (delta <= 0xFFFF)
886 out_one (DW_CFA_advance_loc2);
887 out_two (delta);
889 else
891 out_one (DW_CFA_advance_loc4);
892 out_four (delta);
895 else
897 expressionS exp;
899 exp.X_op = O_subtract;
900 exp.X_add_symbol = to;
901 exp.X_op_symbol = from;
902 exp.X_add_number = 0;
904 /* The code in ehopt.c expects that one byte of the encoding
905 is already allocated to the frag. This comes from the way
906 that it scans the .eh_frame section looking first for the
907 .byte DW_CFA_advance_loc4. */
908 frag_more (1);
910 frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3,
911 make_expr_symbol (&exp), frag_now_fix () - 1,
912 (char *) frag_now);
915 break;
917 case DW_CFA_def_cfa:
918 offset = insn->u.ri.offset;
919 if (offset < 0)
921 out_one (DW_CFA_def_cfa_sf);
922 out_uleb128 (insn->u.ri.reg);
923 out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
925 else
927 out_one (DW_CFA_def_cfa);
928 out_uleb128 (insn->u.ri.reg);
929 out_uleb128 (offset);
931 break;
933 case DW_CFA_def_cfa_register:
934 case DW_CFA_undefined:
935 case DW_CFA_same_value:
936 out_one (insn->insn);
937 out_uleb128 (insn->u.r);
938 break;
940 case DW_CFA_def_cfa_offset:
941 offset = insn->u.i;
942 if (offset < 0)
944 out_one (DW_CFA_def_cfa_offset_sf);
945 out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
947 else
949 out_one (DW_CFA_def_cfa_offset);
950 out_uleb128 (offset);
952 break;
954 case DW_CFA_restore:
955 regno = insn->u.r;
956 if (regno <= 0x3F)
958 out_one (DW_CFA_restore + regno);
960 else
962 out_one (DW_CFA_restore_extended);
963 out_uleb128 (regno);
965 break;
967 case DW_CFA_offset:
968 regno = insn->u.ri.reg;
969 offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT;
970 if (offset < 0)
972 out_one (DW_CFA_offset_extended_sf);
973 out_uleb128 (regno);
974 out_sleb128 (offset);
976 else if (regno <= 0x3F)
978 out_one (DW_CFA_offset + regno);
979 out_uleb128 (offset);
981 else
983 out_one (DW_CFA_offset_extended);
984 out_uleb128 (regno);
985 out_uleb128 (offset);
987 break;
989 case DW_CFA_register:
990 out_one (DW_CFA_register);
991 out_uleb128 (insn->u.rr.reg1);
992 out_uleb128 (insn->u.rr.reg2);
993 break;
995 case DW_CFA_remember_state:
996 case DW_CFA_restore_state:
997 out_one (insn->insn);
998 break;
1000 case DW_CFA_GNU_window_save:
1001 out_one (DW_CFA_GNU_window_save);
1002 break;
1004 case CFI_escape:
1006 struct cfi_escape_data *e;
1007 for (e = insn->u.esc; e ; e = e->next)
1008 emit_expr (&e->exp, 1);
1009 break;
1012 default:
1013 abort ();
1017 static offsetT
1018 encoding_size (unsigned char encoding)
1020 if (encoding == DW_EH_PE_omit)
1021 return 0;
1022 switch (encoding & 0x7)
1024 case 0:
1025 return bfd_get_arch_size (stdoutput) == 64 ? 8 : 4;
1026 case DW_EH_PE_udata2:
1027 return 2;
1028 case DW_EH_PE_udata4:
1029 return 4;
1030 case DW_EH_PE_udata8:
1031 return 8;
1032 default:
1033 abort ();
1037 static void
1038 output_cie (struct cie_entry *cie)
1040 symbolS *after_size_address, *end_address;
1041 expressionS exp;
1042 struct cfi_insn_data *i;
1043 offsetT augmentation_size;
1045 cie->start_address = symbol_temp_new_now ();
1046 after_size_address = symbol_temp_make ();
1047 end_address = symbol_temp_make ();
1049 exp.X_op = O_subtract;
1050 exp.X_add_symbol = end_address;
1051 exp.X_op_symbol = after_size_address;
1052 exp.X_add_number = 0;
1054 emit_expr (&exp, 4); /* Length. */
1055 symbol_set_value_now (after_size_address);
1056 out_four (0); /* CIE id. */
1057 out_one (DW_CIE_VERSION); /* Version. */
1058 out_one ('z'); /* Augmentation. */
1059 if (cie->per_encoding != DW_EH_PE_omit)
1060 out_one ('P');
1061 if (cie->lsda_encoding != DW_EH_PE_omit)
1062 out_one ('L');
1063 out_one ('R');
1064 if (cie->signal_frame)
1065 out_one ('S');
1066 out_one (0);
1067 out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */
1068 out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */
1069 if (DW_CIE_VERSION == 1) /* Return column. */
1070 out_one (cie->return_column);
1071 else
1072 out_uleb128 (cie->return_column);
1073 augmentation_size = 1 + (cie->lsda_encoding != DW_EH_PE_omit);
1074 if (cie->per_encoding != DW_EH_PE_omit)
1075 augmentation_size += 1 + encoding_size (cie->per_encoding);
1076 out_uleb128 (augmentation_size); /* Augmentation size. */
1077 if (cie->per_encoding != DW_EH_PE_omit)
1079 offsetT size = encoding_size (cie->per_encoding);
1080 out_one (cie->per_encoding);
1081 exp = cie->personality;
1082 if ((cie->per_encoding & 0x70) == DW_EH_PE_pcrel)
1084 #ifdef DIFF_EXPR_OK
1085 exp.X_op = O_subtract;
1086 exp.X_op_symbol = symbol_temp_new_now ();
1087 emit_expr (&exp, size);
1088 #elif defined (tc_cfi_emit_pcrel_expr)
1089 tc_cfi_emit_pcrel_expr (&exp, size);
1090 #else
1091 abort ();
1092 #endif
1094 else
1095 emit_expr (&exp, size);
1097 if (cie->lsda_encoding != DW_EH_PE_omit)
1098 out_one (cie->lsda_encoding);
1099 #if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
1100 out_one (DW_EH_PE_pcrel | DW_EH_PE_sdata4);
1101 #else
1102 out_one (DW_EH_PE_sdata4);
1103 #endif
1105 if (cie->first)
1106 for (i = cie->first; i != cie->last; i = i->next)
1107 output_cfi_insn (i);
1109 frag_align (2, DW_CFA_nop, 0);
1110 symbol_set_value_now (end_address);
1113 static void
1114 output_fde (struct fde_entry *fde, struct cie_entry *cie,
1115 struct cfi_insn_data *first, int align)
1117 symbolS *after_size_address, *end_address;
1118 expressionS exp;
1119 offsetT augmentation_size;
1121 after_size_address = symbol_temp_make ();
1122 end_address = symbol_temp_make ();
1124 exp.X_op = O_subtract;
1125 exp.X_add_symbol = end_address;
1126 exp.X_op_symbol = after_size_address;
1127 exp.X_add_number = 0;
1128 emit_expr (&exp, 4); /* Length. */
1129 symbol_set_value_now (after_size_address);
1131 exp.X_add_symbol = after_size_address;
1132 exp.X_op_symbol = cie->start_address;
1133 emit_expr (&exp, 4); /* CIE offset. */
1135 #ifdef DIFF_EXPR_OK
1136 exp.X_add_symbol = fde->start_address;
1137 exp.X_op_symbol = symbol_temp_new_now ();
1138 emit_expr (&exp, 4); /* Code offset. */
1139 #else
1140 exp.X_op = O_symbol;
1141 exp.X_add_symbol = fde->start_address;
1142 exp.X_op_symbol = NULL;
1143 #ifdef tc_cfi_emit_pcrel_expr
1144 tc_cfi_emit_pcrel_expr (&exp, 4); /* Code offset. */
1145 #else
1146 emit_expr (&exp, 4); /* Code offset. */
1147 #endif
1148 exp.X_op = O_subtract;
1149 #endif
1151 exp.X_add_symbol = fde->end_address;
1152 exp.X_op_symbol = fde->start_address; /* Code length. */
1153 emit_expr (&exp, 4);
1155 augmentation_size = encoding_size (fde->lsda_encoding);
1156 out_uleb128 (augmentation_size); /* Augmentation size. */
1158 if (fde->lsda_encoding != DW_EH_PE_omit)
1160 exp = fde->lsda;
1161 if ((fde->lsda_encoding & 0x70) == DW_EH_PE_pcrel)
1163 #ifdef DIFF_EXPR_OK
1164 exp.X_op = O_subtract;
1165 exp.X_op_symbol = symbol_temp_new_now ();
1166 emit_expr (&exp, augmentation_size);
1167 #elif defined (tc_cfi_emit_pcrel_expr)
1168 tc_cfi_emit_pcrel_expr (&exp, augmentation_size);
1169 #else
1170 abort ();
1171 #endif
1173 else
1174 emit_expr (&exp, augmentation_size);
1177 for (; first; first = first->next)
1178 output_cfi_insn (first);
1180 frag_align (align, DW_CFA_nop, 0);
1181 symbol_set_value_now (end_address);
1184 static struct cie_entry *
1185 select_cie_for_fde (struct fde_entry *fde, struct cfi_insn_data **pfirst)
1187 struct cfi_insn_data *i, *j;
1188 struct cie_entry *cie;
1190 for (cie = cie_root; cie; cie = cie->next)
1192 if (cie->return_column != fde->return_column
1193 || cie->signal_frame != fde->signal_frame
1194 || cie->per_encoding != fde->per_encoding
1195 || cie->lsda_encoding != fde->lsda_encoding)
1196 continue;
1197 if (cie->per_encoding != DW_EH_PE_omit)
1199 if (cie->personality.X_op != fde->personality.X_op
1200 || cie->personality.X_add_number
1201 != fde->personality.X_add_number)
1202 continue;
1203 switch (cie->personality.X_op)
1205 case O_constant:
1206 if (cie->personality.X_unsigned != fde->personality.X_unsigned)
1207 continue;
1208 break;
1209 case O_symbol:
1210 if (cie->personality.X_add_symbol
1211 != fde->personality.X_add_symbol)
1212 continue;
1213 break;
1214 default:
1215 abort ();
1218 for (i = cie->first, j = fde->data;
1219 i != cie->last && j != NULL;
1220 i = i->next, j = j->next)
1222 if (i->insn != j->insn)
1223 goto fail;
1224 switch (i->insn)
1226 case DW_CFA_advance_loc:
1227 case DW_CFA_remember_state:
1228 /* We reached the first advance/remember in the FDE,
1229 but did not reach the end of the CIE list. */
1230 goto fail;
1232 case DW_CFA_offset:
1233 case DW_CFA_def_cfa:
1234 if (i->u.ri.reg != j->u.ri.reg)
1235 goto fail;
1236 if (i->u.ri.offset != j->u.ri.offset)
1237 goto fail;
1238 break;
1240 case DW_CFA_register:
1241 if (i->u.rr.reg1 != j->u.rr.reg1)
1242 goto fail;
1243 if (i->u.rr.reg2 != j->u.rr.reg2)
1244 goto fail;
1245 break;
1247 case DW_CFA_def_cfa_register:
1248 case DW_CFA_restore:
1249 case DW_CFA_undefined:
1250 case DW_CFA_same_value:
1251 if (i->u.r != j->u.r)
1252 goto fail;
1253 break;
1255 case DW_CFA_def_cfa_offset:
1256 if (i->u.i != j->u.i)
1257 goto fail;
1258 break;
1260 case CFI_escape:
1261 /* Don't bother matching these for now. */
1262 goto fail;
1264 default:
1265 abort ();
1269 /* Success if we reached the end of the CIE list, and we've either
1270 run out of FDE entries or we've encountered an advance,
1271 remember, or escape. */
1272 if (i == cie->last
1273 && (!j
1274 || j->insn == DW_CFA_advance_loc
1275 || j->insn == DW_CFA_remember_state
1276 || j->insn == CFI_escape))
1278 *pfirst = j;
1279 return cie;
1282 fail:;
1285 cie = xmalloc (sizeof (struct cie_entry));
1286 cie->next = cie_root;
1287 cie_root = cie;
1288 cie->return_column = fde->return_column;
1289 cie->signal_frame = fde->signal_frame;
1290 cie->per_encoding = fde->per_encoding;
1291 cie->lsda_encoding = fde->lsda_encoding;
1292 cie->personality = fde->personality;
1293 cie->first = fde->data;
1295 for (i = cie->first; i ; i = i->next)
1296 if (i->insn == DW_CFA_advance_loc
1297 || i->insn == DW_CFA_remember_state
1298 || i->insn == CFI_escape)
1299 break;
1301 cie->last = i;
1302 *pfirst = i;
1304 output_cie (cie);
1306 return cie;
1309 void
1310 cfi_finish (void)
1312 segT cfi_seg;
1313 struct fde_entry *fde;
1314 int save_flag_traditional_format;
1316 if (all_fde_data == 0)
1317 return;
1319 /* Open .eh_frame section. */
1320 cfi_seg = subseg_new (".eh_frame", 0);
1321 bfd_set_section_flags (stdoutput, cfi_seg,
1322 SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_READONLY);
1323 subseg_set (cfi_seg, 0);
1324 record_alignment (cfi_seg, EH_FRAME_ALIGNMENT);
1326 /* Make sure check_eh_frame doesn't do anything with our output. */
1327 save_flag_traditional_format = flag_traditional_format;
1328 flag_traditional_format = 1;
1330 for (fde = all_fde_data; fde ; fde = fde->next)
1332 struct cfi_insn_data *first;
1333 struct cie_entry *cie;
1335 if (fde->end_address == NULL)
1337 as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
1338 fde->end_address = fde->start_address;
1341 cie = select_cie_for_fde (fde, &first);
1342 output_fde (fde, cie, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2);
1345 flag_traditional_format = save_flag_traditional_format;
1348 #else /* TARGET_USE_CFIPOP */
1349 void
1350 cfi_finish (void)
1353 #endif /* TARGET_USE_CFIPOP */