1 /* Frame unwinder for frames with DWARF Call Frame Information.
3 Copyright 2003, 2004, 2005 Free Software Foundation, Inc.
5 Contributed by Mark Kettenis.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "dwarf2expr.h"
26 #include "elf/dwarf2.h"
28 #include "frame-base.h"
29 #include "frame-unwind.h"
36 #include "gdb_assert.h"
37 #include "gdb_string.h"
39 #include "complaints.h"
40 #include "dwarf2-frame.h"
42 /* Call Frame Information (CFI). */
44 /* Common Information Entry (CIE). */
48 /* Offset into the .debug_frame section where this CIE was found.
49 Used to identify this CIE. */
52 /* Constant that is factored out of all advance location
54 ULONGEST code_alignment_factor;
56 /* Constants that is factored out of all offset instructions. */
57 LONGEST data_alignment_factor;
59 /* Return address column. */
60 ULONGEST return_address_register;
62 /* Instruction sequence to initialize a register set. */
63 unsigned char *initial_instructions;
66 /* Encoding of addresses. */
67 unsigned char encoding;
69 /* True if a 'z' augmentation existed. */
70 unsigned char saw_z_augmentation;
72 struct dwarf2_cie *next;
75 /* Frame Description Entry (FDE). */
79 /* CIE for this FDE. */
80 struct dwarf2_cie *cie;
82 /* First location associated with this FDE. */
83 CORE_ADDR initial_location;
85 /* Number of bytes of program instructions described by this FDE. */
86 CORE_ADDR address_range;
88 /* Instruction sequence. */
89 unsigned char *instructions;
92 struct dwarf2_fde *next;
95 static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc);
98 /* Structure describing a frame state. */
100 struct dwarf2_frame_state
102 /* Each register save state can be described in terms of a CFA slot,
103 another register, or a location expression. */
104 struct dwarf2_frame_state_reg_info
106 struct dwarf2_frame_state_reg *reg;
109 /* Used to implement DW_CFA_remember_state. */
110 struct dwarf2_frame_state_reg_info *prev;
115 unsigned char *cfa_exp;
122 /* The PC described by the current frame state. */
125 /* Initial register set from the CIE.
126 Used to implement DW_CFA_restore. */
127 struct dwarf2_frame_state_reg_info initial;
129 /* The information we care about from the CIE. */
132 ULONGEST retaddr_column;
135 /* Store the length the expression for the CFA in the `cfa_reg' field,
136 which is unused in that case. */
137 #define cfa_exp_len cfa_reg
139 /* Assert that the register set RS is large enough to store NUM_REGS
140 columns. If necessary, enlarge the register set. */
143 dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs,
146 size_t size = sizeof (struct dwarf2_frame_state_reg);
148 if (num_regs <= rs->num_regs)
151 rs->reg = (struct dwarf2_frame_state_reg *)
152 xrealloc (rs->reg, num_regs * size);
154 /* Initialize newly allocated registers. */
155 memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size);
156 rs->num_regs = num_regs;
159 /* Copy the register columns in register set RS into newly allocated
160 memory and return a pointer to this newly created copy. */
162 static struct dwarf2_frame_state_reg *
163 dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs)
165 size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg);
166 struct dwarf2_frame_state_reg *reg;
168 reg = (struct dwarf2_frame_state_reg *) xmalloc (size);
169 memcpy (reg, rs->reg, size);
174 /* Release the memory allocated to register set RS. */
177 dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs)
181 dwarf2_frame_state_free_regs (rs->prev);
188 /* Release the memory allocated to the frame state FS. */
191 dwarf2_frame_state_free (void *p)
193 struct dwarf2_frame_state *fs = p;
195 dwarf2_frame_state_free_regs (fs->initial.prev);
196 dwarf2_frame_state_free_regs (fs->regs.prev);
197 xfree (fs->initial.reg);
198 xfree (fs->regs.reg);
203 /* Helper functions for execute_stack_op. */
206 read_reg (void *baton, int reg)
208 struct frame_info *next_frame = (struct frame_info *) baton;
209 struct gdbarch *gdbarch = get_frame_arch (next_frame);
213 regnum = DWARF2_REG_TO_REGNUM (reg);
215 buf = (char *) alloca (register_size (gdbarch, regnum));
216 frame_unwind_register (next_frame, regnum, buf);
217 return extract_typed_address (buf, builtin_type_void_data_ptr);
221 read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len)
223 read_memory (addr, buf, len);
227 no_get_frame_base (void *baton, unsigned char **start, size_t *length)
229 internal_error (__FILE__, __LINE__,
230 _("Support for DW_OP_fbreg is unimplemented"));
234 no_get_tls_address (void *baton, CORE_ADDR offset)
236 internal_error (__FILE__, __LINE__,
237 _("Support for DW_OP_GNU_push_tls_address is unimplemented"));
241 execute_stack_op (unsigned char *exp, ULONGEST len,
242 struct frame_info *next_frame, CORE_ADDR initial)
244 struct dwarf_expr_context *ctx;
247 ctx = new_dwarf_expr_context ();
248 ctx->baton = next_frame;
249 ctx->read_reg = read_reg;
250 ctx->read_mem = read_mem;
251 ctx->get_frame_base = no_get_frame_base;
252 ctx->get_tls_address = no_get_tls_address;
254 dwarf_expr_push (ctx, initial);
255 dwarf_expr_eval (ctx, exp, len);
256 result = dwarf_expr_fetch (ctx, 0);
259 result = read_reg (next_frame, result);
261 free_dwarf_expr_context (ctx);
268 execute_cfa_program (unsigned char *insn_ptr, unsigned char *insn_end,
269 struct frame_info *next_frame,
270 struct dwarf2_frame_state *fs)
272 CORE_ADDR pc = frame_pc_unwind (next_frame);
275 while (insn_ptr < insn_end && fs->pc <= pc)
277 unsigned char insn = *insn_ptr++;
281 if ((insn & 0xc0) == DW_CFA_advance_loc)
282 fs->pc += (insn & 0x3f) * fs->code_align;
283 else if ((insn & 0xc0) == DW_CFA_offset)
286 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
287 offset = utmp * fs->data_align;
288 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
289 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
290 fs->regs.reg[reg].loc.offset = offset;
292 else if ((insn & 0xc0) == DW_CFA_restore)
294 gdb_assert (fs->initial.reg);
296 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
297 fs->regs.reg[reg] = fs->initial.reg[reg];
304 fs->pc = dwarf2_read_address (insn_ptr, insn_end, &bytes_read);
305 insn_ptr += bytes_read;
308 case DW_CFA_advance_loc1:
309 utmp = extract_unsigned_integer (insn_ptr, 1);
310 fs->pc += utmp * fs->code_align;
313 case DW_CFA_advance_loc2:
314 utmp = extract_unsigned_integer (insn_ptr, 2);
315 fs->pc += utmp * fs->code_align;
318 case DW_CFA_advance_loc4:
319 utmp = extract_unsigned_integer (insn_ptr, 4);
320 fs->pc += utmp * fs->code_align;
324 case DW_CFA_offset_extended:
325 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
326 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
327 offset = utmp * fs->data_align;
328 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
329 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
330 fs->regs.reg[reg].loc.offset = offset;
333 case DW_CFA_restore_extended:
334 gdb_assert (fs->initial.reg);
335 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
336 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
337 fs->regs.reg[reg] = fs->initial.reg[reg];
340 case DW_CFA_undefined:
341 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
342 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
343 fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED;
346 case DW_CFA_same_value:
347 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
348 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
349 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE;
352 case DW_CFA_register:
353 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
354 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
355 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
356 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
357 fs->regs.reg[reg].loc.reg = utmp;
360 case DW_CFA_remember_state:
362 struct dwarf2_frame_state_reg_info *new_rs;
364 new_rs = XMALLOC (struct dwarf2_frame_state_reg_info);
366 fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs);
367 fs->regs.prev = new_rs;
371 case DW_CFA_restore_state:
373 struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev;
377 complaint (&symfile_complaints, _("\
378 bad CFI data; mismatched DW_CFA_restore_state at 0x%s"), paddr (fs->pc));
382 xfree (fs->regs.reg);
390 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
391 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
392 fs->cfa_offset = utmp;
393 fs->cfa_how = CFA_REG_OFFSET;
396 case DW_CFA_def_cfa_register:
397 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
398 fs->cfa_how = CFA_REG_OFFSET;
401 case DW_CFA_def_cfa_offset:
402 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_offset);
403 /* cfa_how deliberately not set. */
409 case DW_CFA_def_cfa_expression:
410 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_exp_len);
411 fs->cfa_exp = insn_ptr;
412 fs->cfa_how = CFA_EXP;
413 insn_ptr += fs->cfa_exp_len;
416 case DW_CFA_expression:
417 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
418 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
419 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
420 fs->regs.reg[reg].loc.exp = insn_ptr;
421 fs->regs.reg[reg].exp_len = utmp;
422 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP;
426 case DW_CFA_offset_extended_sf:
427 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
428 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
429 offset *= fs->data_align;
430 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
431 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
432 fs->regs.reg[reg].loc.offset = offset;
435 case DW_CFA_def_cfa_sf:
436 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
437 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
438 fs->cfa_offset = offset * fs->data_align;
439 fs->cfa_how = CFA_REG_OFFSET;
442 case DW_CFA_def_cfa_offset_sf:
443 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
444 fs->cfa_offset = offset * fs->data_align;
445 /* cfa_how deliberately not set. */
448 case DW_CFA_GNU_window_save:
449 /* This is SPARC-specific code, and contains hard-coded
450 constants for the register numbering scheme used by
451 GCC. Rather than having a architecture-specific
452 operation that's only ever used by a single
453 architecture, we provide the implementation here.
454 Incidentally that's what GCC does too in its
457 struct gdbarch *gdbarch = get_frame_arch (next_frame);
458 int size = register_size(gdbarch, 0);
459 dwarf2_frame_state_alloc_regs (&fs->regs, 32);
460 for (reg = 8; reg < 16; reg++)
462 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
463 fs->regs.reg[reg].loc.reg = reg + 16;
465 for (reg = 16; reg < 32; reg++)
467 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
468 fs->regs.reg[reg].loc.offset = (reg - 16) * size;
473 case DW_CFA_GNU_args_size:
475 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
479 internal_error (__FILE__, __LINE__, _("Unknown CFI encountered."));
484 /* Don't allow remember/restore between CIE and FDE programs. */
485 dwarf2_frame_state_free_regs (fs->regs.prev);
486 fs->regs.prev = NULL;
490 /* Architecture-specific operations. */
492 /* Per-architecture data key. */
493 static struct gdbarch_data *dwarf2_frame_data;
495 struct dwarf2_frame_ops
497 /* Pre-initialize the register state REG for register REGNUM. */
498 void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *);
500 /* Check whether the frame preceding NEXT_FRAME will be a signal
502 int (*signal_frame_p) (struct gdbarch *, struct frame_info *);
505 /* Default architecture-specific register state initialization
509 dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
510 struct dwarf2_frame_state_reg *reg)
512 /* If we have a register that acts as a program counter, mark it as
513 a destination for the return address. If we have a register that
514 serves as the stack pointer, arrange for it to be filled with the
515 call frame address (CFA). The other registers are marked as
518 We copy the return address to the program counter, since many
519 parts in GDB assume that it is possible to get the return address
520 by unwinding the program counter register. However, on ISA's
521 with a dedicated return address register, the CFI usually only
522 contains information to unwind that return address register.
524 The reason we're treating the stack pointer special here is
525 because in many cases GCC doesn't emit CFI for the stack pointer
526 and implicitly assumes that it is equal to the CFA. This makes
527 some sense since the DWARF specification (version 3, draft 8,
530 "Typically, the CFA is defined to be the value of the stack
531 pointer at the call site in the previous frame (which may be
532 different from its value on entry to the current frame)."
534 However, this isn't true for all platforms supported by GCC
535 (e.g. IBM S/390 and zSeries). Those architectures should provide
536 their own architecture-specific initialization function. */
538 if (regnum == PC_REGNUM)
539 reg->how = DWARF2_FRAME_REG_RA;
540 else if (regnum == SP_REGNUM)
541 reg->how = DWARF2_FRAME_REG_CFA;
544 /* Return a default for the architecture-specific operations. */
547 dwarf2_frame_init (struct obstack *obstack)
549 struct dwarf2_frame_ops *ops;
551 ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops);
552 ops->init_reg = dwarf2_frame_default_init_reg;
556 /* Set the architecture-specific register state initialization
557 function for GDBARCH to INIT_REG. */
560 dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
561 void (*init_reg) (struct gdbarch *, int,
562 struct dwarf2_frame_state_reg *))
564 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
566 ops->init_reg = init_reg;
569 /* Pre-initialize the register state REG for register REGNUM. */
572 dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
573 struct dwarf2_frame_state_reg *reg)
575 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
577 ops->init_reg (gdbarch, regnum, reg);
580 /* Set the architecture-specific signal trampoline recognition
581 function for GDBARCH to SIGNAL_FRAME_P. */
584 dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
585 int (*signal_frame_p) (struct gdbarch *,
586 struct frame_info *))
588 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
590 ops->signal_frame_p = signal_frame_p;
593 /* Query the architecture-specific signal frame recognizer for
597 dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch,
598 struct frame_info *next_frame)
600 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
602 if (ops->signal_frame_p == NULL)
604 return ops->signal_frame_p (gdbarch, next_frame);
608 struct dwarf2_frame_cache
610 /* DWARF Call Frame Address. */
613 /* Saved registers, indexed by GDB register number, not by DWARF
615 struct dwarf2_frame_state_reg *reg;
617 /* Return address register. */
618 struct dwarf2_frame_state_reg retaddr_reg;
621 static struct dwarf2_frame_cache *
622 dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
624 struct cleanup *old_chain;
625 struct gdbarch *gdbarch = get_frame_arch (next_frame);
626 const int num_regs = NUM_REGS + NUM_PSEUDO_REGS;
627 struct dwarf2_frame_cache *cache;
628 struct dwarf2_frame_state *fs;
629 struct dwarf2_fde *fde;
634 /* Allocate a new cache. */
635 cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache);
636 cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg);
638 /* Allocate and initialize the frame state. */
639 fs = XMALLOC (struct dwarf2_frame_state);
640 memset (fs, 0, sizeof (struct dwarf2_frame_state));
641 old_chain = make_cleanup (dwarf2_frame_state_free, fs);
645 Note that if NEXT_FRAME is never supposed to return (i.e. a call
646 to abort), the compiler might optimize away the instruction at
647 NEXT_FRAME's return address. As a result the return address will
648 point at some random instruction, and the CFI for that
649 instruction is probably worthless to us. GCC's unwinder solves
650 this problem by substracting 1 from the return address to get an
651 address in the middle of a presumed call instruction (or the
652 instruction in the associated delay slot). This should only be
653 done for "normal" frames and not for resume-type frames (signal
654 handlers, sentinel frames, dummy frames). The function
655 frame_unwind_address_in_block does just this. It's not clear how
656 reliable the method is though; there is the potential for the
657 register state pre-call being different to that on return. */
658 fs->pc = frame_unwind_address_in_block (next_frame);
660 /* Find the correct FDE. */
661 fde = dwarf2_frame_find_fde (&fs->pc);
662 gdb_assert (fde != NULL);
664 /* Extract any interesting information from the CIE. */
665 fs->data_align = fde->cie->data_alignment_factor;
666 fs->code_align = fde->cie->code_alignment_factor;
667 fs->retaddr_column = fde->cie->return_address_register;
669 /* First decode all the insns in the CIE. */
670 execute_cfa_program (fde->cie->initial_instructions,
671 fde->cie->end, next_frame, fs);
673 /* Save the initialized register set. */
674 fs->initial = fs->regs;
675 fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs);
677 /* Then decode the insns in the FDE up to our target PC. */
678 execute_cfa_program (fde->instructions, fde->end, next_frame, fs);
680 /* Caclulate the CFA. */
684 cache->cfa = read_reg (next_frame, fs->cfa_reg);
685 cache->cfa += fs->cfa_offset;
690 execute_stack_op (fs->cfa_exp, fs->cfa_exp_len, next_frame, 0);
694 internal_error (__FILE__, __LINE__, _("Unknown CFA rule."));
697 /* Initialize the register state. */
701 for (regnum = 0; regnum < num_regs; regnum++)
702 dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum]);
705 /* Go through the DWARF2 CFI generated table and save its register
706 location information in the cache. Note that we don't skip the
707 return address column; it's perfectly all right for it to
708 correspond to a real register. If it doesn't correspond to a
709 real register, or if we shouldn't treat it as such,
710 DWARF2_REG_TO_REGNUM should be defined to return a number outside
711 the range [0, NUM_REGS). */
713 int column; /* CFI speak for "register number". */
715 for (column = 0; column < fs->regs.num_regs; column++)
717 /* Use the GDB register number as the destination index. */
718 int regnum = DWARF2_REG_TO_REGNUM (column);
720 /* If there's no corresponding GDB register, ignore it. */
721 if (regnum < 0 || regnum >= num_regs)
724 /* NOTE: cagney/2003-09-05: CFI should specify the disposition
725 of all debug info registers. If it doesn't, complain (but
726 not too loudly). It turns out that GCC assumes that an
727 unspecified register implies "same value" when CFI (draft
728 7) specifies nothing at all. Such a register could equally
729 be interpreted as "undefined". Also note that this check
730 isn't sufficient; it only checks that all registers in the
731 range [0 .. max column] are specified, and won't detect
732 problems when a debug info register falls outside of the
733 table. We need a way of iterating through all the valid
734 DWARF2 register numbers. */
735 if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED)
737 if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED)
738 complaint (&symfile_complaints, _("\
739 incomplete CFI data; unspecified registers (e.g., %s) at 0x%s"),
740 gdbarch_register_name (gdbarch, regnum),
744 cache->reg[regnum] = fs->regs.reg[column];
748 /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information
749 we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */
753 for (regnum = 0; regnum < num_regs; regnum++)
755 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA
756 || cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET)
758 struct dwarf2_frame_state_reg *retaddr_reg =
759 &fs->regs.reg[fs->retaddr_column];
761 /* It seems rather bizarre to specify an "empty" column as
762 the return adress column. However, this is exactly
763 what GCC does on some targets. It turns out that GCC
764 assumes that the return address can be found in the
765 register corresponding to the return address column.
766 Incidentally, that's how we should treat a return
767 address column specifying "same value" too. */
768 if (fs->retaddr_column < fs->regs.num_regs
769 && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED
770 && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE)
772 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
773 cache->reg[regnum] = *retaddr_reg;
775 cache->retaddr_reg = *retaddr_reg;
779 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
781 cache->reg[regnum].loc.reg = fs->retaddr_column;
782 cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG;
786 cache->retaddr_reg.loc.reg = fs->retaddr_column;
787 cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG;
794 do_cleanups (old_chain);
801 dwarf2_frame_this_id (struct frame_info *next_frame, void **this_cache,
802 struct frame_id *this_id)
804 struct dwarf2_frame_cache *cache =
805 dwarf2_frame_cache (next_frame, this_cache);
807 (*this_id) = frame_id_build (cache->cfa, frame_func_unwind (next_frame));
811 dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache,
812 int regnum, int *optimizedp,
813 enum lval_type *lvalp, CORE_ADDR *addrp,
814 int *realnump, void *valuep)
816 struct gdbarch *gdbarch = get_frame_arch (next_frame);
817 struct dwarf2_frame_cache *cache =
818 dwarf2_frame_cache (next_frame, this_cache);
820 switch (cache->reg[regnum].how)
822 case DWARF2_FRAME_REG_UNDEFINED:
823 /* If CFI explicitly specified that the value isn't defined,
824 mark it as optimized away; the value isn't available. */
831 /* In some cases, for example %eflags on the i386, we have
832 to provide a sane value, even though this register wasn't
833 saved. Assume we can get it from NEXT_FRAME. */
834 frame_unwind_register (next_frame, regnum, valuep);
838 case DWARF2_FRAME_REG_SAVED_OFFSET:
840 *lvalp = lval_memory;
841 *addrp = cache->cfa + cache->reg[regnum].loc.offset;
845 /* Read the value in from memory. */
846 read_memory (*addrp, valuep, register_size (gdbarch, regnum));
850 case DWARF2_FRAME_REG_SAVED_REG:
852 *lvalp = lval_register;
854 *realnump = DWARF2_REG_TO_REGNUM (cache->reg[regnum].loc.reg);
856 frame_unwind_register (next_frame, (*realnump), valuep);
859 case DWARF2_FRAME_REG_SAVED_EXP:
861 *lvalp = lval_memory;
862 *addrp = execute_stack_op (cache->reg[regnum].loc.exp,
863 cache->reg[regnum].exp_len,
864 next_frame, cache->cfa);
868 /* Read the value in from memory. */
869 read_memory (*addrp, valuep, register_size (gdbarch, regnum));
873 case DWARF2_FRAME_REG_UNSPECIFIED:
874 /* GCC, in its infinite wisdom decided to not provide unwind
875 information for registers that are "same value". Since
876 DWARF2 (3 draft 7) doesn't define such behavior, said
877 registers are actually undefined (which is different to CFI
878 "undefined"). Code above issues a complaint about this.
879 Here just fudge the books, assume GCC, and that the value is
880 more inner on the stack. */
882 *lvalp = lval_register;
886 frame_unwind_register (next_frame, (*realnump), valuep);
889 case DWARF2_FRAME_REG_SAME_VALUE:
891 *lvalp = lval_register;
895 frame_unwind_register (next_frame, (*realnump), valuep);
898 case DWARF2_FRAME_REG_CFA:
905 /* Store the value. */
906 store_typed_address (valuep, builtin_type_void_data_ptr, cache->cfa);
910 case DWARF2_FRAME_REG_RA_OFFSET:
917 CORE_ADDR pc = cache->reg[regnum].loc.offset;
919 regnum = DWARF2_REG_TO_REGNUM (cache->retaddr_reg.loc.reg);
920 pc += frame_unwind_register_unsigned (next_frame, regnum);
921 store_typed_address (valuep, builtin_type_void_func_ptr, pc);
926 internal_error (__FILE__, __LINE__, _("Unknown register rule."));
930 static const struct frame_unwind dwarf2_frame_unwind =
933 dwarf2_frame_this_id,
934 dwarf2_frame_prev_register
937 static const struct frame_unwind dwarf2_signal_frame_unwind =
940 dwarf2_frame_this_id,
941 dwarf2_frame_prev_register
944 const struct frame_unwind *
945 dwarf2_frame_sniffer (struct frame_info *next_frame)
947 /* Grab an address that is guarenteed to reside somewhere within the
948 function. frame_pc_unwind(), for a no-return next function, can
949 end up returning something past the end of this function's body. */
950 CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame);
951 if (!dwarf2_frame_find_fde (&block_addr))
954 /* On some targets, signal trampolines may have unwind information.
955 We need to recognize them so that we set the frame type
958 if (dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
960 return &dwarf2_signal_frame_unwind;
962 return &dwarf2_frame_unwind;
966 /* There is no explicitly defined relationship between the CFA and the
967 location of frame's local variables and arguments/parameters.
968 Therefore, frame base methods on this page should probably only be
969 used as a last resort, just to avoid printing total garbage as a
970 response to the "info frame" command. */
973 dwarf2_frame_base_address (struct frame_info *next_frame, void **this_cache)
975 struct dwarf2_frame_cache *cache =
976 dwarf2_frame_cache (next_frame, this_cache);
981 static const struct frame_base dwarf2_frame_base =
983 &dwarf2_frame_unwind,
984 dwarf2_frame_base_address,
985 dwarf2_frame_base_address,
986 dwarf2_frame_base_address
989 const struct frame_base *
990 dwarf2_frame_base_sniffer (struct frame_info *next_frame)
992 CORE_ADDR pc = frame_pc_unwind (next_frame);
993 if (dwarf2_frame_find_fde (&pc))
994 return &dwarf2_frame_base;
999 /* A minimal decoding of DWARF2 compilation units. We only decode
1000 what's needed to get to the call frame information. */
1004 /* Keep the bfd convenient. */
1007 struct objfile *objfile;
1009 /* Linked list of CIEs for this object. */
1010 struct dwarf2_cie *cie;
1012 /* Pointer to the .debug_frame section loaded into memory. */
1013 char *dwarf_frame_buffer;
1015 /* Length of the loaded .debug_frame section. */
1016 unsigned long dwarf_frame_size;
1018 /* Pointer to the .debug_frame section. */
1019 asection *dwarf_frame_section;
1021 /* Base for DW_EH_PE_datarel encodings. */
1024 /* Base for DW_EH_PE_textrel encodings. */
1028 const struct objfile_data *dwarf2_frame_objfile_data;
1031 read_1_byte (bfd *bfd, char *buf)
1033 return bfd_get_8 (abfd, (bfd_byte *) buf);
1037 read_4_bytes (bfd *abfd, char *buf)
1039 return bfd_get_32 (abfd, (bfd_byte *) buf);
1043 read_8_bytes (bfd *abfd, char *buf)
1045 return bfd_get_64 (abfd, (bfd_byte *) buf);
1049 read_unsigned_leb128 (bfd *abfd, char *buf, unsigned int *bytes_read_ptr)
1052 unsigned int num_read;
1062 byte = bfd_get_8 (abfd, (bfd_byte *) buf);
1065 result |= ((byte & 0x7f) << shift);
1068 while (byte & 0x80);
1070 *bytes_read_ptr = num_read;
1076 read_signed_leb128 (bfd *abfd, char *buf, unsigned int *bytes_read_ptr)
1080 unsigned int num_read;
1089 byte = bfd_get_8 (abfd, (bfd_byte *) buf);
1092 result |= ((byte & 0x7f) << shift);
1095 while (byte & 0x80);
1097 if ((shift < 32) && (byte & 0x40))
1098 result |= -(1 << shift);
1100 *bytes_read_ptr = num_read;
1106 read_initial_length (bfd *abfd, char *buf, unsigned int *bytes_read_ptr)
1110 result = bfd_get_32 (abfd, (bfd_byte *) buf);
1111 if (result == 0xffffffff)
1113 result = bfd_get_64 (abfd, (bfd_byte *) buf + 4);
1114 *bytes_read_ptr = 12;
1117 *bytes_read_ptr = 4;
1123 /* Pointer encoding helper functions. */
1125 /* GCC supports exception handling based on DWARF2 CFI. However, for
1126 technical reasons, it encodes addresses in its FDE's in a different
1127 way. Several "pointer encodings" are supported. The encoding
1128 that's used for a particular FDE is determined by the 'R'
1129 augmentation in the associated CIE. The argument of this
1130 augmentation is a single byte.
1132 The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a
1133 LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether
1134 the address is signed or unsigned. Bits 4, 5 and 6 encode how the
1135 address should be interpreted (absolute, relative to the current
1136 position in the FDE, ...). Bit 7, indicates that the address
1137 should be dereferenced. */
1139 static unsigned char
1140 encoding_for_size (unsigned int size)
1145 return DW_EH_PE_udata2;
1147 return DW_EH_PE_udata4;
1149 return DW_EH_PE_udata8;
1151 internal_error (__FILE__, __LINE__, _("Unsupported address size"));
1156 size_of_encoded_value (unsigned char encoding)
1158 if (encoding == DW_EH_PE_omit)
1161 switch (encoding & 0x07)
1163 case DW_EH_PE_absptr:
1164 return TYPE_LENGTH (builtin_type_void_data_ptr);
1165 case DW_EH_PE_udata2:
1167 case DW_EH_PE_udata4:
1169 case DW_EH_PE_udata8:
1172 internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
1177 read_encoded_value (struct comp_unit *unit, unsigned char encoding,
1178 unsigned char *buf, unsigned int *bytes_read_ptr)
1180 int ptr_len = size_of_encoded_value (DW_EH_PE_absptr);
1184 /* GCC currently doesn't generate DW_EH_PE_indirect encodings for
1186 if (encoding & DW_EH_PE_indirect)
1187 internal_error (__FILE__, __LINE__,
1188 _("Unsupported encoding: DW_EH_PE_indirect"));
1190 *bytes_read_ptr = 0;
1192 switch (encoding & 0x70)
1194 case DW_EH_PE_absptr:
1197 case DW_EH_PE_pcrel:
1198 base = bfd_get_section_vma (unit->bfd, unit->dwarf_frame_section);
1199 base += ((char *) buf - unit->dwarf_frame_buffer);
1201 case DW_EH_PE_datarel:
1204 case DW_EH_PE_textrel:
1207 case DW_EH_PE_funcrel:
1208 /* FIXME: kettenis/20040501: For now just pretend
1209 DW_EH_PE_funcrel is equivalent to DW_EH_PE_absptr. For
1210 reading the initial location of an FDE it should be treated
1211 as such, and currently that's the only place where this code
1215 case DW_EH_PE_aligned:
1217 offset = (char *) buf - unit->dwarf_frame_buffer;
1218 if ((offset % ptr_len) != 0)
1220 *bytes_read_ptr = ptr_len - (offset % ptr_len);
1221 buf += *bytes_read_ptr;
1225 internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
1228 if ((encoding & 0x07) == 0x00)
1229 encoding |= encoding_for_size (ptr_len);
1231 switch (encoding & 0x0f)
1233 case DW_EH_PE_uleb128:
1236 unsigned char *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
1237 *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf;
1238 return base + value;
1240 case DW_EH_PE_udata2:
1241 *bytes_read_ptr += 2;
1242 return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf));
1243 case DW_EH_PE_udata4:
1244 *bytes_read_ptr += 4;
1245 return (base + bfd_get_32 (unit->abfd, (bfd_byte *) buf));
1246 case DW_EH_PE_udata8:
1247 *bytes_read_ptr += 8;
1248 return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf));
1249 case DW_EH_PE_sleb128:
1252 char *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
1253 *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf;
1254 return base + value;
1256 case DW_EH_PE_sdata2:
1257 *bytes_read_ptr += 2;
1258 return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf));
1259 case DW_EH_PE_sdata4:
1260 *bytes_read_ptr += 4;
1261 return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf));
1262 case DW_EH_PE_sdata8:
1263 *bytes_read_ptr += 8;
1264 return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf));
1266 internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
1271 /* GCC uses a single CIE for all FDEs in a .debug_frame section.
1272 That's why we use a simple linked list here. */
1274 static struct dwarf2_cie *
1275 find_cie (struct comp_unit *unit, ULONGEST cie_pointer)
1277 struct dwarf2_cie *cie = unit->cie;
1281 if (cie->cie_pointer == cie_pointer)
1291 add_cie (struct comp_unit *unit, struct dwarf2_cie *cie)
1293 cie->next = unit->cie;
1297 /* Find the FDE for *PC. Return a pointer to the FDE, and store the
1298 inital location associated with it into *PC. */
1300 static struct dwarf2_fde *
1301 dwarf2_frame_find_fde (CORE_ADDR *pc)
1303 struct objfile *objfile;
1305 ALL_OBJFILES (objfile)
1307 struct dwarf2_fde *fde;
1310 fde = objfile_data (objfile, dwarf2_frame_objfile_data);
1314 gdb_assert (objfile->section_offsets);
1315 offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
1319 if (*pc >= fde->initial_location + offset
1320 && *pc < fde->initial_location + offset + fde->address_range)
1322 *pc = fde->initial_location + offset;
1334 add_fde (struct comp_unit *unit, struct dwarf2_fde *fde)
1336 fde->next = objfile_data (unit->objfile, dwarf2_frame_objfile_data);
1337 set_objfile_data (unit->objfile, dwarf2_frame_objfile_data, fde);
1340 #ifdef CC_HAS_LONG_LONG
1341 #define DW64_CIE_ID 0xffffffffffffffffULL
1343 #define DW64_CIE_ID ~0
1346 static char *decode_frame_entry (struct comp_unit *unit, char *start,
1349 /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise
1350 the next byte to be processed. */
1352 decode_frame_entry_1 (struct comp_unit *unit, char *start, int eh_frame_p)
1356 unsigned int bytes_read;
1359 ULONGEST cie_pointer;
1363 length = read_initial_length (unit->abfd, buf, &bytes_read);
1367 /* Are we still within the section? */
1368 if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size)
1374 /* Distinguish between 32 and 64-bit encoded frame info. */
1375 dwarf64_p = (bytes_read == 12);
1377 /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */
1381 cie_id = DW64_CIE_ID;
1387 cie_pointer = read_8_bytes (unit->abfd, buf);
1392 cie_pointer = read_4_bytes (unit->abfd, buf);
1396 if (cie_pointer == cie_id)
1398 /* This is a CIE. */
1399 struct dwarf2_cie *cie;
1401 unsigned int cie_version;
1403 /* Record the offset into the .debug_frame section of this CIE. */
1404 cie_pointer = start - unit->dwarf_frame_buffer;
1406 /* Check whether we've already read it. */
1407 if (find_cie (unit, cie_pointer))
1410 cie = (struct dwarf2_cie *)
1411 obstack_alloc (&unit->objfile->objfile_obstack,
1412 sizeof (struct dwarf2_cie));
1413 cie->initial_instructions = NULL;
1414 cie->cie_pointer = cie_pointer;
1416 /* The encoding for FDE's in a normal .debug_frame section
1417 depends on the target address size. */
1418 cie->encoding = DW_EH_PE_absptr;
1420 /* Check version number. */
1421 cie_version = read_1_byte (unit->abfd, buf);
1422 if (cie_version != 1 && cie_version != 3)
1426 /* Interpret the interesting bits of the augmentation. */
1428 buf = augmentation + strlen (augmentation) + 1;
1430 /* The GCC 2.x "eh" augmentation has a pointer immediately
1431 following the augmentation string, so it must be handled
1433 if (augmentation[0] == 'e' && augmentation[1] == 'h')
1436 buf += TYPE_LENGTH (builtin_type_void_data_ptr);
1440 cie->code_alignment_factor =
1441 read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
1444 cie->data_alignment_factor =
1445 read_signed_leb128 (unit->abfd, buf, &bytes_read);
1448 if (cie_version == 1)
1450 cie->return_address_register = read_1_byte (unit->abfd, buf);
1454 cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf,
1458 cie->saw_z_augmentation = (*augmentation == 'z');
1459 if (cie->saw_z_augmentation)
1463 length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
1467 cie->initial_instructions = buf + length;
1471 while (*augmentation)
1473 /* "L" indicates a byte showing how the LSDA pointer is encoded. */
1474 if (*augmentation == 'L')
1481 /* "R" indicates a byte indicating how FDE addresses are encoded. */
1482 else if (*augmentation == 'R')
1484 cie->encoding = *buf++;
1488 /* "P" indicates a personality routine in the CIE augmentation. */
1489 else if (*augmentation == 'P')
1491 /* Skip. Avoid indirection since we throw away the result. */
1492 unsigned char encoding = (*buf++) & ~DW_EH_PE_indirect;
1493 read_encoded_value (unit, encoding, buf, &bytes_read);
1498 /* Otherwise we have an unknown augmentation.
1499 Bail out unless we saw a 'z' prefix. */
1502 if (cie->initial_instructions == NULL)
1505 /* Skip unknown augmentations. */
1506 buf = cie->initial_instructions;
1511 cie->initial_instructions = buf;
1514 add_cie (unit, cie);
1518 /* This is a FDE. */
1519 struct dwarf2_fde *fde;
1521 /* In an .eh_frame section, the CIE pointer is the delta between the
1522 address within the FDE where the CIE pointer is stored and the
1523 address of the CIE. Convert it to an offset into the .eh_frame
1527 cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer;
1528 cie_pointer -= (dwarf64_p ? 8 : 4);
1531 /* In either case, validate the result is still within the section. */
1532 if (cie_pointer >= unit->dwarf_frame_size)
1535 fde = (struct dwarf2_fde *)
1536 obstack_alloc (&unit->objfile->objfile_obstack,
1537 sizeof (struct dwarf2_fde));
1538 fde->cie = find_cie (unit, cie_pointer);
1539 if (fde->cie == NULL)
1541 decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer,
1543 fde->cie = find_cie (unit, cie_pointer);
1546 gdb_assert (fde->cie != NULL);
1548 fde->initial_location =
1549 read_encoded_value (unit, fde->cie->encoding, buf, &bytes_read);
1552 fde->address_range =
1553 read_encoded_value (unit, fde->cie->encoding & 0x0f, buf, &bytes_read);
1556 /* A 'z' augmentation in the CIE implies the presence of an
1557 augmentation field in the FDE as well. The only thing known
1558 to be in here at present is the LSDA entry for EH. So we
1559 can skip the whole thing. */
1560 if (fde->cie->saw_z_augmentation)
1564 length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
1565 buf += bytes_read + length;
1570 fde->instructions = buf;
1573 add_fde (unit, fde);
1579 /* Read a CIE or FDE in BUF and decode it. */
1581 decode_frame_entry (struct comp_unit *unit, char *start, int eh_frame_p)
1583 enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
1586 ptrdiff_t start_offset;
1590 ret = decode_frame_entry_1 (unit, start, eh_frame_p);
1594 /* We have corrupt input data of some form. */
1596 /* ??? Try, weakly, to work around compiler/assembler/linker bugs
1597 and mismatches wrt padding and alignment of debug sections. */
1598 /* Note that there is no requirement in the standard for any
1599 alignment at all in the frame unwind sections. Testing for
1600 alignment before trying to interpret data would be incorrect.
1602 However, GCC traditionally arranged for frame sections to be
1603 sized such that the FDE length and CIE fields happen to be
1604 aligned (in theory, for performance). This, unfortunately,
1605 was done with .align directives, which had the side effect of
1606 forcing the section to be aligned by the linker.
1608 This becomes a problem when you have some other producer that
1609 creates frame sections that are not as strictly aligned. That
1610 produces a hole in the frame info that gets filled by the
1613 The GCC behaviour is arguably a bug, but it's effectively now
1614 part of the ABI, so we're now stuck with it, at least at the
1615 object file level. A smart linker may decide, in the process
1616 of compressing duplicate CIE information, that it can rewrite
1617 the entire output section without this extra padding. */
1619 start_offset = start - unit->dwarf_frame_buffer;
1620 if (workaround < ALIGN4 && (start_offset & 3) != 0)
1622 start += 4 - (start_offset & 3);
1623 workaround = ALIGN4;
1626 if (workaround < ALIGN8 && (start_offset & 7) != 0)
1628 start += 8 - (start_offset & 7);
1629 workaround = ALIGN8;
1633 /* Nothing left to try. Arrange to return as if we've consumed
1634 the entire input section. Hopefully we'll get valid info from
1635 the other of .debug_frame/.eh_frame. */
1637 ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size;
1647 complaint (&symfile_complaints,
1648 _("Corrupt data in %s:%s; align 4 workaround apparently succeeded"),
1649 unit->dwarf_frame_section->owner->filename,
1650 unit->dwarf_frame_section->name);
1654 complaint (&symfile_complaints,
1655 _("Corrupt data in %s:%s; align 8 workaround apparently succeeded"),
1656 unit->dwarf_frame_section->owner->filename,
1657 unit->dwarf_frame_section->name);
1661 complaint (&symfile_complaints,
1662 _("Corrupt data in %s:%s"),
1663 unit->dwarf_frame_section->owner->filename,
1664 unit->dwarf_frame_section->name);
1672 /* FIXME: kettenis/20030504: This still needs to be integrated with
1673 dwarf2read.c in a better way. */
1675 /* Imported from dwarf2read.c. */
1676 extern asection *dwarf_frame_section;
1677 extern asection *dwarf_eh_frame_section;
1679 /* Imported from dwarf2read.c. */
1680 extern char *dwarf2_read_section (struct objfile *objfile, asection *sectp);
1683 dwarf2_build_frame_info (struct objfile *objfile)
1685 struct comp_unit unit;
1688 /* Build a minimal decoding of the DWARF2 compilation unit. */
1689 unit.abfd = objfile->obfd;
1690 unit.objfile = objfile;
1694 /* First add the information from the .eh_frame section. That way,
1695 the FDEs from that section are searched last. */
1696 if (dwarf_eh_frame_section)
1698 asection *got, *txt;
1701 unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
1702 dwarf_eh_frame_section);
1704 unit.dwarf_frame_size = bfd_get_section_size (dwarf_eh_frame_section);
1705 unit.dwarf_frame_section = dwarf_eh_frame_section;
1707 /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base
1708 that is used for the i386/amd64 target, which currently is
1709 the only target in GCC that supports/uses the
1710 DW_EH_PE_datarel encoding. */
1711 got = bfd_get_section_by_name (unit.abfd, ".got");
1713 unit.dbase = got->vma;
1715 /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64
1717 txt = bfd_get_section_by_name (unit.abfd, ".text");
1719 unit.tbase = txt->vma;
1721 frame_ptr = unit.dwarf_frame_buffer;
1722 while (frame_ptr < unit.dwarf_frame_buffer + unit.dwarf_frame_size)
1723 frame_ptr = decode_frame_entry (&unit, frame_ptr, 1);
1726 if (dwarf_frame_section)
1729 unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
1730 dwarf_frame_section);
1731 unit.dwarf_frame_size = bfd_get_section_size (dwarf_frame_section);
1732 unit.dwarf_frame_section = dwarf_frame_section;
1734 frame_ptr = unit.dwarf_frame_buffer;
1735 while (frame_ptr < unit.dwarf_frame_buffer + unit.dwarf_frame_size)
1736 frame_ptr = decode_frame_entry (&unit, frame_ptr, 0);
1740 /* Provide a prototype to silence -Wmissing-prototypes. */
1741 void _initialize_dwarf2_frame (void);
1744 _initialize_dwarf2_frame (void)
1746 dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init);
1747 dwarf2_frame_objfile_data = register_objfile_data ();