1 /* Frame unwinder for frames with DWARF Call Frame Information.
3 Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 Contributed by Mark Kettenis.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "dwarf2expr.h"
27 #include "frame-base.h"
28 #include "frame-unwind.h"
36 #include "gdb_assert.h"
37 #include "gdb_string.h"
39 #include "complaints.h"
40 #include "dwarf2-frame.h"
42 #include "dwarf2loc.h"
46 /* Call Frame Information (CFI). */
48 /* Common Information Entry (CIE). */
52 /* Computation Unit for this CIE. */
53 struct comp_unit *unit;
55 /* Offset into the .debug_frame section where this CIE was found.
56 Used to identify this CIE. */
59 /* Constant that is factored out of all advance location
61 ULONGEST code_alignment_factor;
63 /* Constants that is factored out of all offset instructions. */
64 LONGEST data_alignment_factor;
66 /* Return address column. */
67 ULONGEST return_address_register;
69 /* Instruction sequence to initialize a register set. */
70 gdb_byte *initial_instructions;
73 /* Saved augmentation, in case it's needed later. */
76 /* Encoding of addresses. */
79 /* Target address size in bytes. */
82 /* Target pointer size in bytes. */
85 /* True if a 'z' augmentation existed. */
86 unsigned char saw_z_augmentation;
88 /* True if an 'S' augmentation existed. */
89 unsigned char signal_frame;
91 /* The version recorded in the CIE. */
92 unsigned char version;
94 /* The segment size. */
95 unsigned char segment_size;
98 struct dwarf2_cie_table
101 struct dwarf2_cie **entries;
104 /* Frame Description Entry (FDE). */
108 /* CIE for this FDE. */
109 struct dwarf2_cie *cie;
111 /* First location associated with this FDE. */
112 CORE_ADDR initial_location;
114 /* Number of bytes of program instructions described by this FDE. */
115 CORE_ADDR address_range;
117 /* Instruction sequence. */
118 gdb_byte *instructions;
121 /* True if this FDE is read from a .eh_frame instead of a .debug_frame
123 unsigned char eh_frame_p;
126 struct dwarf2_fde_table
129 struct dwarf2_fde **entries;
132 /* A minimal decoding of DWARF2 compilation units. We only decode
133 what's needed to get to the call frame information. */
137 /* Keep the bfd convenient. */
140 struct objfile *objfile;
142 /* Pointer to the .debug_frame section loaded into memory. */
143 gdb_byte *dwarf_frame_buffer;
145 /* Length of the loaded .debug_frame section. */
146 bfd_size_type dwarf_frame_size;
148 /* Pointer to the .debug_frame section. */
149 asection *dwarf_frame_section;
151 /* Base for DW_EH_PE_datarel encodings. */
154 /* Base for DW_EH_PE_textrel encodings. */
158 static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc,
159 CORE_ADDR *out_offset);
161 static int dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum,
164 static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
165 int ptr_len, const gdb_byte *buf,
166 unsigned int *bytes_read_ptr,
167 CORE_ADDR func_base);
170 /* Structure describing a frame state. */
172 struct dwarf2_frame_state
174 /* Each register save state can be described in terms of a CFA slot,
175 another register, or a location expression. */
176 struct dwarf2_frame_state_reg_info
178 struct dwarf2_frame_state_reg *reg;
188 const gdb_byte *cfa_exp;
190 /* Used to implement DW_CFA_remember_state. */
191 struct dwarf2_frame_state_reg_info *prev;
194 /* The PC described by the current frame state. */
197 /* Initial register set from the CIE.
198 Used to implement DW_CFA_restore. */
199 struct dwarf2_frame_state_reg_info initial;
201 /* The information we care about from the CIE. */
204 ULONGEST retaddr_column;
206 /* Flags for known producer quirks. */
208 /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
209 and DW_CFA_def_cfa_offset takes a factored offset. */
210 int armcc_cfa_offsets_sf;
212 /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
213 the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
214 int armcc_cfa_offsets_reversed;
217 /* Store the length the expression for the CFA in the `cfa_reg' field,
218 which is unused in that case. */
219 #define cfa_exp_len cfa_reg
221 /* Assert that the register set RS is large enough to store gdbarch_num_regs
222 columns. If necessary, enlarge the register set. */
225 dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs,
228 size_t size = sizeof (struct dwarf2_frame_state_reg);
230 if (num_regs <= rs->num_regs)
233 rs->reg = (struct dwarf2_frame_state_reg *)
234 xrealloc (rs->reg, num_regs * size);
236 /* Initialize newly allocated registers. */
237 memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size);
238 rs->num_regs = num_regs;
241 /* Copy the register columns in register set RS into newly allocated
242 memory and return a pointer to this newly created copy. */
244 static struct dwarf2_frame_state_reg *
245 dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs)
247 size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg);
248 struct dwarf2_frame_state_reg *reg;
250 reg = (struct dwarf2_frame_state_reg *) xmalloc (size);
251 memcpy (reg, rs->reg, size);
256 /* Release the memory allocated to register set RS. */
259 dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs)
263 dwarf2_frame_state_free_regs (rs->prev);
270 /* Release the memory allocated to the frame state FS. */
273 dwarf2_frame_state_free (void *p)
275 struct dwarf2_frame_state *fs = p;
277 dwarf2_frame_state_free_regs (fs->initial.prev);
278 dwarf2_frame_state_free_regs (fs->regs.prev);
279 xfree (fs->initial.reg);
280 xfree (fs->regs.reg);
285 /* Helper functions for execute_stack_op. */
288 read_reg (void *baton, int reg)
290 struct frame_info *this_frame = (struct frame_info *) baton;
291 struct gdbarch *gdbarch = get_frame_arch (this_frame);
295 regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
297 buf = alloca (register_size (gdbarch, regnum));
298 get_frame_register (this_frame, regnum, buf);
300 /* Convert the register to an integer. This returns a LONGEST
301 rather than a CORE_ADDR, but unpack_pointer does the same thing
302 under the covers, and this makes more sense for non-pointer
303 registers. Maybe read_reg and the associated interfaces should
304 deal with "struct value" instead of CORE_ADDR. */
305 return unpack_long (register_type (gdbarch, regnum), buf);
309 read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
311 read_memory (addr, buf, len);
315 no_get_frame_base (void *baton, const gdb_byte **start, size_t *length)
317 internal_error (__FILE__, __LINE__,
318 _("Support for DW_OP_fbreg is unimplemented"));
321 /* Helper function for execute_stack_op. */
324 no_get_frame_cfa (void *baton)
326 internal_error (__FILE__, __LINE__,
327 _("Support for DW_OP_call_frame_cfa is unimplemented"));
330 /* Helper function for execute_stack_op. */
333 no_get_frame_pc (void *baton)
335 internal_error (__FILE__, __LINE__, _("\
336 Support for DW_OP_GNU_implicit_pointer is unimplemented"));
340 no_get_tls_address (void *baton, CORE_ADDR offset)
342 internal_error (__FILE__, __LINE__, _("\
343 Support for DW_OP_GNU_push_tls_address is unimplemented"));
346 /* Helper function for execute_stack_op. */
349 no_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
351 internal_error (__FILE__, __LINE__,
352 _("Support for DW_OP_call* is invalid in CFI"));
355 /* Execute the required actions for both the DW_CFA_restore and
356 DW_CFA_restore_extended instructions. */
358 dwarf2_restore_rule (struct gdbarch *gdbarch, ULONGEST reg_num,
359 struct dwarf2_frame_state *fs, int eh_frame_p)
363 gdb_assert (fs->initial.reg);
364 reg = dwarf2_frame_adjust_regnum (gdbarch, reg_num, eh_frame_p);
365 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
367 /* Check if this register was explicitly initialized in the
368 CIE initial instructions. If not, default the rule to
370 if (reg < fs->initial.num_regs)
371 fs->regs.reg[reg] = fs->initial.reg[reg];
373 fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED;
375 if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED)
376 complaint (&symfile_complaints, _("\
377 incomplete CFI data; DW_CFA_restore unspecified\n\
378 register %s (#%d) at %s"),
379 gdbarch_register_name
380 (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
381 gdbarch_dwarf2_reg_to_regnum (gdbarch, reg),
382 paddress (gdbarch, fs->pc));
386 execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
387 CORE_ADDR offset, struct frame_info *this_frame,
388 CORE_ADDR initial, int initial_in_stack_memory)
390 struct dwarf_expr_context *ctx;
392 struct cleanup *old_chain;
394 ctx = new_dwarf_expr_context ();
395 old_chain = make_cleanup_free_dwarf_expr_context (ctx);
397 ctx->gdbarch = get_frame_arch (this_frame);
398 ctx->addr_size = addr_size;
399 ctx->offset = offset;
400 ctx->baton = this_frame;
401 ctx->read_reg = read_reg;
402 ctx->read_mem = read_mem;
403 ctx->get_frame_base = no_get_frame_base;
404 ctx->get_frame_cfa = no_get_frame_cfa;
405 ctx->get_frame_pc = no_get_frame_pc;
406 ctx->get_tls_address = no_get_tls_address;
407 ctx->dwarf_call = no_dwarf_call;
409 dwarf_expr_push (ctx, initial, initial_in_stack_memory);
410 dwarf_expr_eval (ctx, exp, len);
412 if (ctx->location == DWARF_VALUE_MEMORY)
413 result = dwarf_expr_fetch_address (ctx, 0);
414 else if (ctx->location == DWARF_VALUE_REGISTER)
415 result = read_reg (this_frame, dwarf_expr_fetch (ctx, 0));
418 /* This is actually invalid DWARF, but if we ever do run across
419 it somehow, we might as well support it. So, instead, report
420 it as unimplemented. */
422 Not implemented: computing unwound register using explicit value operator"));
425 do_cleanups (old_chain);
432 execute_cfa_program (struct dwarf2_fde *fde, const gdb_byte *insn_ptr,
433 const gdb_byte *insn_end, struct gdbarch *gdbarch,
434 CORE_ADDR pc, struct dwarf2_frame_state *fs)
436 int eh_frame_p = fde->eh_frame_p;
438 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
440 while (insn_ptr < insn_end && fs->pc <= pc)
442 gdb_byte insn = *insn_ptr++;
446 if ((insn & 0xc0) == DW_CFA_advance_loc)
447 fs->pc += (insn & 0x3f) * fs->code_align;
448 else if ((insn & 0xc0) == DW_CFA_offset)
451 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
452 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
453 offset = utmp * fs->data_align;
454 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
455 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
456 fs->regs.reg[reg].loc.offset = offset;
458 else if ((insn & 0xc0) == DW_CFA_restore)
461 dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p);
468 fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding,
469 fde->cie->ptr_size, insn_ptr,
470 &bytes_read, fde->initial_location);
471 /* Apply the objfile offset for relocatable objects. */
472 fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets,
473 SECT_OFF_TEXT (fde->cie->unit->objfile));
474 insn_ptr += bytes_read;
477 case DW_CFA_advance_loc1:
478 utmp = extract_unsigned_integer (insn_ptr, 1, byte_order);
479 fs->pc += utmp * fs->code_align;
482 case DW_CFA_advance_loc2:
483 utmp = extract_unsigned_integer (insn_ptr, 2, byte_order);
484 fs->pc += utmp * fs->code_align;
487 case DW_CFA_advance_loc4:
488 utmp = extract_unsigned_integer (insn_ptr, 4, byte_order);
489 fs->pc += utmp * fs->code_align;
493 case DW_CFA_offset_extended:
494 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
495 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
496 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
497 offset = utmp * fs->data_align;
498 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
499 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
500 fs->regs.reg[reg].loc.offset = offset;
503 case DW_CFA_restore_extended:
504 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
505 dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p);
508 case DW_CFA_undefined:
509 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
510 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
511 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
512 fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED;
515 case DW_CFA_same_value:
516 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
517 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
518 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
519 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE;
522 case DW_CFA_register:
523 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
524 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
525 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
526 utmp = dwarf2_frame_adjust_regnum (gdbarch, utmp, eh_frame_p);
527 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
528 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
529 fs->regs.reg[reg].loc.reg = utmp;
532 case DW_CFA_remember_state:
534 struct dwarf2_frame_state_reg_info *new_rs;
536 new_rs = XMALLOC (struct dwarf2_frame_state_reg_info);
538 fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs);
539 fs->regs.prev = new_rs;
543 case DW_CFA_restore_state:
545 struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev;
549 complaint (&symfile_complaints, _("\
550 bad CFI data; mismatched DW_CFA_restore_state at %s"),
551 paddress (gdbarch, fs->pc));
555 xfree (fs->regs.reg);
563 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg);
564 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
566 if (fs->armcc_cfa_offsets_sf)
567 utmp *= fs->data_align;
569 fs->regs.cfa_offset = utmp;
570 fs->regs.cfa_how = CFA_REG_OFFSET;
573 case DW_CFA_def_cfa_register:
574 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg);
575 fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch,
578 fs->regs.cfa_how = CFA_REG_OFFSET;
581 case DW_CFA_def_cfa_offset:
582 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
584 if (fs->armcc_cfa_offsets_sf)
585 utmp *= fs->data_align;
587 fs->regs.cfa_offset = utmp;
588 /* cfa_how deliberately not set. */
594 case DW_CFA_def_cfa_expression:
595 insn_ptr = read_uleb128 (insn_ptr, insn_end,
596 &fs->regs.cfa_exp_len);
597 fs->regs.cfa_exp = insn_ptr;
598 fs->regs.cfa_how = CFA_EXP;
599 insn_ptr += fs->regs.cfa_exp_len;
602 case DW_CFA_expression:
603 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
604 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
605 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
606 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
607 fs->regs.reg[reg].loc.exp = insn_ptr;
608 fs->regs.reg[reg].exp_len = utmp;
609 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP;
613 case DW_CFA_offset_extended_sf:
614 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
615 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
616 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
617 offset *= fs->data_align;
618 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
619 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
620 fs->regs.reg[reg].loc.offset = offset;
623 case DW_CFA_val_offset:
624 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
625 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
626 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
627 offset = utmp * fs->data_align;
628 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET;
629 fs->regs.reg[reg].loc.offset = offset;
632 case DW_CFA_val_offset_sf:
633 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
634 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
635 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
636 offset *= fs->data_align;
637 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET;
638 fs->regs.reg[reg].loc.offset = offset;
641 case DW_CFA_val_expression:
642 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
643 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
644 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
645 fs->regs.reg[reg].loc.exp = insn_ptr;
646 fs->regs.reg[reg].exp_len = utmp;
647 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_EXP;
651 case DW_CFA_def_cfa_sf:
652 insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg);
653 fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch,
656 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
657 fs->regs.cfa_offset = offset * fs->data_align;
658 fs->regs.cfa_how = CFA_REG_OFFSET;
661 case DW_CFA_def_cfa_offset_sf:
662 insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
663 fs->regs.cfa_offset = offset * fs->data_align;
664 /* cfa_how deliberately not set. */
667 case DW_CFA_GNU_window_save:
668 /* This is SPARC-specific code, and contains hard-coded
669 constants for the register numbering scheme used by
670 GCC. Rather than having a architecture-specific
671 operation that's only ever used by a single
672 architecture, we provide the implementation here.
673 Incidentally that's what GCC does too in its
676 int size = register_size (gdbarch, 0);
678 dwarf2_frame_state_alloc_regs (&fs->regs, 32);
679 for (reg = 8; reg < 16; reg++)
681 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
682 fs->regs.reg[reg].loc.reg = reg + 16;
684 for (reg = 16; reg < 32; reg++)
686 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
687 fs->regs.reg[reg].loc.offset = (reg - 16) * size;
692 case DW_CFA_GNU_args_size:
694 insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
697 case DW_CFA_GNU_negative_offset_extended:
698 insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
699 reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
700 insn_ptr = read_uleb128 (insn_ptr, insn_end, &offset);
701 offset *= fs->data_align;
702 dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
703 fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
704 fs->regs.reg[reg].loc.offset = -offset;
708 internal_error (__FILE__, __LINE__,
709 _("Unknown CFI encountered."));
714 /* Don't allow remember/restore between CIE and FDE programs. */
715 dwarf2_frame_state_free_regs (fs->regs.prev);
716 fs->regs.prev = NULL;
720 /* Architecture-specific operations. */
722 /* Per-architecture data key. */
723 static struct gdbarch_data *dwarf2_frame_data;
725 struct dwarf2_frame_ops
727 /* Pre-initialize the register state REG for register REGNUM. */
728 void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *,
729 struct frame_info *);
731 /* Check whether the THIS_FRAME is a signal trampoline. */
732 int (*signal_frame_p) (struct gdbarch *, struct frame_info *);
734 /* Convert .eh_frame register number to DWARF register number, or
735 adjust .debug_frame register number. */
736 int (*adjust_regnum) (struct gdbarch *, int, int);
739 /* Default architecture-specific register state initialization
743 dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
744 struct dwarf2_frame_state_reg *reg,
745 struct frame_info *this_frame)
747 /* If we have a register that acts as a program counter, mark it as
748 a destination for the return address. If we have a register that
749 serves as the stack pointer, arrange for it to be filled with the
750 call frame address (CFA). The other registers are marked as
753 We copy the return address to the program counter, since many
754 parts in GDB assume that it is possible to get the return address
755 by unwinding the program counter register. However, on ISA's
756 with a dedicated return address register, the CFI usually only
757 contains information to unwind that return address register.
759 The reason we're treating the stack pointer special here is
760 because in many cases GCC doesn't emit CFI for the stack pointer
761 and implicitly assumes that it is equal to the CFA. This makes
762 some sense since the DWARF specification (version 3, draft 8,
765 "Typically, the CFA is defined to be the value of the stack
766 pointer at the call site in the previous frame (which may be
767 different from its value on entry to the current frame)."
769 However, this isn't true for all platforms supported by GCC
770 (e.g. IBM S/390 and zSeries). Those architectures should provide
771 their own architecture-specific initialization function. */
773 if (regnum == gdbarch_pc_regnum (gdbarch))
774 reg->how = DWARF2_FRAME_REG_RA;
775 else if (regnum == gdbarch_sp_regnum (gdbarch))
776 reg->how = DWARF2_FRAME_REG_CFA;
779 /* Return a default for the architecture-specific operations. */
782 dwarf2_frame_init (struct obstack *obstack)
784 struct dwarf2_frame_ops *ops;
786 ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops);
787 ops->init_reg = dwarf2_frame_default_init_reg;
791 /* Set the architecture-specific register state initialization
792 function for GDBARCH to INIT_REG. */
795 dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
796 void (*init_reg) (struct gdbarch *, int,
797 struct dwarf2_frame_state_reg *,
798 struct frame_info *))
800 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
802 ops->init_reg = init_reg;
805 /* Pre-initialize the register state REG for register REGNUM. */
808 dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
809 struct dwarf2_frame_state_reg *reg,
810 struct frame_info *this_frame)
812 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
814 ops->init_reg (gdbarch, regnum, reg, this_frame);
817 /* Set the architecture-specific signal trampoline recognition
818 function for GDBARCH to SIGNAL_FRAME_P. */
821 dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
822 int (*signal_frame_p) (struct gdbarch *,
823 struct frame_info *))
825 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
827 ops->signal_frame_p = signal_frame_p;
830 /* Query the architecture-specific signal frame recognizer for
834 dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch,
835 struct frame_info *this_frame)
837 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
839 if (ops->signal_frame_p == NULL)
841 return ops->signal_frame_p (gdbarch, this_frame);
844 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
848 dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch,
849 int (*adjust_regnum) (struct gdbarch *,
852 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
854 ops->adjust_regnum = adjust_regnum;
857 /* Translate a .eh_frame register to DWARF register, or adjust a .debug_frame
861 dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch,
862 int regnum, int eh_frame_p)
864 struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
866 if (ops->adjust_regnum == NULL)
868 return ops->adjust_regnum (gdbarch, regnum, eh_frame_p);
872 dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs,
873 struct dwarf2_fde *fde)
877 s = find_pc_symtab (fs->pc);
881 if (producer_is_realview (s->producer))
883 if (fde->cie->version == 1)
884 fs->armcc_cfa_offsets_sf = 1;
886 if (fde->cie->version == 1)
887 fs->armcc_cfa_offsets_reversed = 1;
889 /* The reversed offset problem is present in some compilers
890 using DWARF3, but it was eventually fixed. Check the ARM
891 defined augmentations, which are in the format "armcc" followed
892 by a list of one-character options. The "+" option means
893 this problem is fixed (no quirk needed). If the armcc
894 augmentation is missing, the quirk is needed. */
895 if (fde->cie->version == 3
896 && (strncmp (fde->cie->augmentation, "armcc", 5) != 0
897 || strchr (fde->cie->augmentation + 5, '+') == NULL))
898 fs->armcc_cfa_offsets_reversed = 1;
906 dwarf2_compile_cfa_to_ax (struct agent_expr *expr, struct axs_value *loc,
907 struct gdbarch *gdbarch,
909 struct dwarf2_per_cu_data *data)
911 const int num_regs = gdbarch_num_regs (gdbarch)
912 + gdbarch_num_pseudo_regs (gdbarch);
913 struct dwarf2_fde *fde;
914 CORE_ADDR text_offset, cfa;
915 struct dwarf2_frame_state fs;
918 memset (&fs, 0, sizeof (struct dwarf2_frame_state));
922 /* Find the correct FDE. */
923 fde = dwarf2_frame_find_fde (&fs.pc, &text_offset);
925 error (_("Could not compute CFA; needed to translate this expression"));
927 /* Extract any interesting information from the CIE. */
928 fs.data_align = fde->cie->data_alignment_factor;
929 fs.code_align = fde->cie->code_alignment_factor;
930 fs.retaddr_column = fde->cie->return_address_register;
931 addr_size = fde->cie->addr_size;
933 /* Check for "quirks" - known bugs in producers. */
934 dwarf2_frame_find_quirks (&fs, fde);
936 /* First decode all the insns in the CIE. */
937 execute_cfa_program (fde, fde->cie->initial_instructions,
938 fde->cie->end, gdbarch, pc, &fs);
940 /* Save the initialized register set. */
941 fs.initial = fs.regs;
942 fs.initial.reg = dwarf2_frame_state_copy_regs (&fs.regs);
944 /* Then decode the insns in the FDE up to our target PC. */
945 execute_cfa_program (fde, fde->instructions, fde->end, gdbarch, pc, &fs);
947 /* Calculate the CFA. */
948 switch (fs.regs.cfa_how)
952 int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, fs.regs.cfa_reg);
955 error (_("Unable to access DWARF register number %d"),
956 (int) fs.regs.cfa_reg); /* FIXME */
957 ax_reg (expr, regnum);
959 if (fs.regs.cfa_offset != 0)
961 if (fs.armcc_cfa_offsets_reversed)
962 ax_const_l (expr, -fs.regs.cfa_offset);
964 ax_const_l (expr, fs.regs.cfa_offset);
965 ax_simple (expr, aop_add);
971 ax_const_l (expr, text_offset);
972 dwarf2_compile_expr_to_ax (expr, loc, gdbarch, addr_size,
974 fs.regs.cfa_exp + fs.regs.cfa_exp_len,
979 internal_error (__FILE__, __LINE__, _("Unknown CFA rule."));
984 struct dwarf2_frame_cache
986 /* DWARF Call Frame Address. */
989 /* Set if the return address column was marked as undefined. */
990 int undefined_retaddr;
992 /* Saved registers, indexed by GDB register number, not by DWARF
994 struct dwarf2_frame_state_reg *reg;
996 /* Return address register. */
997 struct dwarf2_frame_state_reg retaddr_reg;
999 /* Target address size in bytes. */
1002 /* The .text offset. */
1003 CORE_ADDR text_offset;
1006 static struct dwarf2_frame_cache *
1007 dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache)
1009 struct cleanup *old_chain;
1010 struct gdbarch *gdbarch = get_frame_arch (this_frame);
1011 const int num_regs = gdbarch_num_regs (gdbarch)
1012 + gdbarch_num_pseudo_regs (gdbarch);
1013 struct dwarf2_frame_cache *cache;
1014 struct dwarf2_frame_state *fs;
1015 struct dwarf2_fde *fde;
1020 /* Allocate a new cache. */
1021 cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache);
1022 cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg);
1024 /* Allocate and initialize the frame state. */
1025 fs = XMALLOC (struct dwarf2_frame_state);
1026 memset (fs, 0, sizeof (struct dwarf2_frame_state));
1027 old_chain = make_cleanup (dwarf2_frame_state_free, fs);
1031 Note that if the next frame is never supposed to return (i.e. a call
1032 to abort), the compiler might optimize away the instruction at
1033 its return address. As a result the return address will
1034 point at some random instruction, and the CFI for that
1035 instruction is probably worthless to us. GCC's unwinder solves
1036 this problem by substracting 1 from the return address to get an
1037 address in the middle of a presumed call instruction (or the
1038 instruction in the associated delay slot). This should only be
1039 done for "normal" frames and not for resume-type frames (signal
1040 handlers, sentinel frames, dummy frames). The function
1041 get_frame_address_in_block does just this. It's not clear how
1042 reliable the method is though; there is the potential for the
1043 register state pre-call being different to that on return. */
1044 fs->pc = get_frame_address_in_block (this_frame);
1046 /* Find the correct FDE. */
1047 fde = dwarf2_frame_find_fde (&fs->pc, &cache->text_offset);
1048 gdb_assert (fde != NULL);
1050 /* Extract any interesting information from the CIE. */
1051 fs->data_align = fde->cie->data_alignment_factor;
1052 fs->code_align = fde->cie->code_alignment_factor;
1053 fs->retaddr_column = fde->cie->return_address_register;
1054 cache->addr_size = fde->cie->addr_size;
1056 /* Check for "quirks" - known bugs in producers. */
1057 dwarf2_frame_find_quirks (fs, fde);
1059 /* First decode all the insns in the CIE. */
1060 execute_cfa_program (fde, fde->cie->initial_instructions,
1061 fde->cie->end, gdbarch, get_frame_pc (this_frame), fs);
1063 /* Save the initialized register set. */
1064 fs->initial = fs->regs;
1065 fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs);
1067 /* Then decode the insns in the FDE up to our target PC. */
1068 execute_cfa_program (fde, fde->instructions, fde->end, gdbarch,
1069 get_frame_pc (this_frame), fs);
1071 /* Calculate the CFA. */
1072 switch (fs->regs.cfa_how)
1074 case CFA_REG_OFFSET:
1075 cache->cfa = read_reg (this_frame, fs->regs.cfa_reg);
1076 if (fs->armcc_cfa_offsets_reversed)
1077 cache->cfa -= fs->regs.cfa_offset;
1079 cache->cfa += fs->regs.cfa_offset;
1084 execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len,
1085 cache->addr_size, cache->text_offset,
1090 internal_error (__FILE__, __LINE__, _("Unknown CFA rule."));
1093 /* Initialize the register state. */
1097 for (regnum = 0; regnum < num_regs; regnum++)
1098 dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], this_frame);
1101 /* Go through the DWARF2 CFI generated table and save its register
1102 location information in the cache. Note that we don't skip the
1103 return address column; it's perfectly all right for it to
1104 correspond to a real register. If it doesn't correspond to a
1105 real register, or if we shouldn't treat it as such,
1106 gdbarch_dwarf2_reg_to_regnum should be defined to return a number outside
1107 the range [0, gdbarch_num_regs). */
1109 int column; /* CFI speak for "register number". */
1111 for (column = 0; column < fs->regs.num_regs; column++)
1113 /* Use the GDB register number as the destination index. */
1114 int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column);
1116 /* If there's no corresponding GDB register, ignore it. */
1117 if (regnum < 0 || regnum >= num_regs)
1120 /* NOTE: cagney/2003-09-05: CFI should specify the disposition
1121 of all debug info registers. If it doesn't, complain (but
1122 not too loudly). It turns out that GCC assumes that an
1123 unspecified register implies "same value" when CFI (draft
1124 7) specifies nothing at all. Such a register could equally
1125 be interpreted as "undefined". Also note that this check
1126 isn't sufficient; it only checks that all registers in the
1127 range [0 .. max column] are specified, and won't detect
1128 problems when a debug info register falls outside of the
1129 table. We need a way of iterating through all the valid
1130 DWARF2 register numbers. */
1131 if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED)
1133 if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED)
1134 complaint (&symfile_complaints, _("\
1135 incomplete CFI data; unspecified registers (e.g., %s) at %s"),
1136 gdbarch_register_name (gdbarch, regnum),
1137 paddress (gdbarch, fs->pc));
1140 cache->reg[regnum] = fs->regs.reg[column];
1144 /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information
1145 we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */
1149 for (regnum = 0; regnum < num_regs; regnum++)
1151 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA
1152 || cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET)
1154 struct dwarf2_frame_state_reg *retaddr_reg =
1155 &fs->regs.reg[fs->retaddr_column];
1157 /* It seems rather bizarre to specify an "empty" column as
1158 the return adress column. However, this is exactly
1159 what GCC does on some targets. It turns out that GCC
1160 assumes that the return address can be found in the
1161 register corresponding to the return address column.
1162 Incidentally, that's how we should treat a return
1163 address column specifying "same value" too. */
1164 if (fs->retaddr_column < fs->regs.num_regs
1165 && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED
1166 && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE)
1168 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
1169 cache->reg[regnum] = *retaddr_reg;
1171 cache->retaddr_reg = *retaddr_reg;
1175 if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
1177 cache->reg[regnum].loc.reg = fs->retaddr_column;
1178 cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG;
1182 cache->retaddr_reg.loc.reg = fs->retaddr_column;
1183 cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG;
1190 if (fs->retaddr_column < fs->regs.num_regs
1191 && fs->regs.reg[fs->retaddr_column].how == DWARF2_FRAME_REG_UNDEFINED)
1192 cache->undefined_retaddr = 1;
1194 do_cleanups (old_chain);
1196 *this_cache = cache;
1201 dwarf2_frame_this_id (struct frame_info *this_frame, void **this_cache,
1202 struct frame_id *this_id)
1204 struct dwarf2_frame_cache *cache =
1205 dwarf2_frame_cache (this_frame, this_cache);
1207 if (cache->undefined_retaddr)
1210 (*this_id) = frame_id_build (cache->cfa, get_frame_func (this_frame));
1213 static struct value *
1214 dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache,
1217 struct gdbarch *gdbarch = get_frame_arch (this_frame);
1218 struct dwarf2_frame_cache *cache =
1219 dwarf2_frame_cache (this_frame, this_cache);
1223 switch (cache->reg[regnum].how)
1225 case DWARF2_FRAME_REG_UNDEFINED:
1226 /* If CFI explicitly specified that the value isn't defined,
1227 mark it as optimized away; the value isn't available. */
1228 return frame_unwind_got_optimized (this_frame, regnum);
1230 case DWARF2_FRAME_REG_SAVED_OFFSET:
1231 addr = cache->cfa + cache->reg[regnum].loc.offset;
1232 return frame_unwind_got_memory (this_frame, regnum, addr);
1234 case DWARF2_FRAME_REG_SAVED_REG:
1236 = gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg);
1237 return frame_unwind_got_register (this_frame, regnum, realnum);
1239 case DWARF2_FRAME_REG_SAVED_EXP:
1240 addr = execute_stack_op (cache->reg[regnum].loc.exp,
1241 cache->reg[regnum].exp_len,
1242 cache->addr_size, cache->text_offset,
1243 this_frame, cache->cfa, 1);
1244 return frame_unwind_got_memory (this_frame, regnum, addr);
1246 case DWARF2_FRAME_REG_SAVED_VAL_OFFSET:
1247 addr = cache->cfa + cache->reg[regnum].loc.offset;
1248 return frame_unwind_got_constant (this_frame, regnum, addr);
1250 case DWARF2_FRAME_REG_SAVED_VAL_EXP:
1251 addr = execute_stack_op (cache->reg[regnum].loc.exp,
1252 cache->reg[regnum].exp_len,
1253 cache->addr_size, cache->text_offset,
1254 this_frame, cache->cfa, 1);
1255 return frame_unwind_got_constant (this_frame, regnum, addr);
1257 case DWARF2_FRAME_REG_UNSPECIFIED:
1258 /* GCC, in its infinite wisdom decided to not provide unwind
1259 information for registers that are "same value". Since
1260 DWARF2 (3 draft 7) doesn't define such behavior, said
1261 registers are actually undefined (which is different to CFI
1262 "undefined"). Code above issues a complaint about this.
1263 Here just fudge the books, assume GCC, and that the value is
1264 more inner on the stack. */
1265 return frame_unwind_got_register (this_frame, regnum, regnum);
1267 case DWARF2_FRAME_REG_SAME_VALUE:
1268 return frame_unwind_got_register (this_frame, regnum, regnum);
1270 case DWARF2_FRAME_REG_CFA:
1271 return frame_unwind_got_address (this_frame, regnum, cache->cfa);
1273 case DWARF2_FRAME_REG_CFA_OFFSET:
1274 addr = cache->cfa + cache->reg[regnum].loc.offset;
1275 return frame_unwind_got_address (this_frame, regnum, addr);
1277 case DWARF2_FRAME_REG_RA_OFFSET:
1278 addr = cache->reg[regnum].loc.offset;
1279 regnum = gdbarch_dwarf2_reg_to_regnum
1280 (gdbarch, cache->retaddr_reg.loc.reg);
1281 addr += get_frame_register_unsigned (this_frame, regnum);
1282 return frame_unwind_got_address (this_frame, regnum, addr);
1284 case DWARF2_FRAME_REG_FN:
1285 return cache->reg[regnum].loc.fn (this_frame, this_cache, regnum);
1288 internal_error (__FILE__, __LINE__, _("Unknown register rule."));
1293 dwarf2_frame_sniffer (const struct frame_unwind *self,
1294 struct frame_info *this_frame, void **this_cache)
1296 /* Grab an address that is guarenteed to reside somewhere within the
1297 function. get_frame_pc(), with a no-return next function, can
1298 end up returning something past the end of this function's body.
1299 If the frame we're sniffing for is a signal frame whose start
1300 address is placed on the stack by the OS, its FDE must
1301 extend one byte before its start address or we could potentially
1302 select the FDE of the previous function. */
1303 CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
1304 struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr, NULL);
1309 /* On some targets, signal trampolines may have unwind information.
1310 We need to recognize them so that we set the frame type
1313 if (fde->cie->signal_frame
1314 || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame),
1316 return self->type == SIGTRAMP_FRAME;
1318 return self->type != SIGTRAMP_FRAME;
1321 static const struct frame_unwind dwarf2_frame_unwind =
1324 dwarf2_frame_this_id,
1325 dwarf2_frame_prev_register,
1327 dwarf2_frame_sniffer
1330 static const struct frame_unwind dwarf2_signal_frame_unwind =
1333 dwarf2_frame_this_id,
1334 dwarf2_frame_prev_register,
1336 dwarf2_frame_sniffer
1339 /* Append the DWARF-2 frame unwinders to GDBARCH's list. */
1342 dwarf2_append_unwinders (struct gdbarch *gdbarch)
1344 frame_unwind_append_unwinder (gdbarch, &dwarf2_frame_unwind);
1345 frame_unwind_append_unwinder (gdbarch, &dwarf2_signal_frame_unwind);
1349 /* There is no explicitly defined relationship between the CFA and the
1350 location of frame's local variables and arguments/parameters.
1351 Therefore, frame base methods on this page should probably only be
1352 used as a last resort, just to avoid printing total garbage as a
1353 response to the "info frame" command. */
1356 dwarf2_frame_base_address (struct frame_info *this_frame, void **this_cache)
1358 struct dwarf2_frame_cache *cache =
1359 dwarf2_frame_cache (this_frame, this_cache);
1364 static const struct frame_base dwarf2_frame_base =
1366 &dwarf2_frame_unwind,
1367 dwarf2_frame_base_address,
1368 dwarf2_frame_base_address,
1369 dwarf2_frame_base_address
1372 const struct frame_base *
1373 dwarf2_frame_base_sniffer (struct frame_info *this_frame)
1375 CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
1377 if (dwarf2_frame_find_fde (&block_addr, NULL))
1378 return &dwarf2_frame_base;
1383 /* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from
1384 the DWARF unwinder. This is used to implement
1385 DW_OP_call_frame_cfa. */
1388 dwarf2_frame_cfa (struct frame_info *this_frame)
1390 while (get_frame_type (this_frame) == INLINE_FRAME)
1391 this_frame = get_prev_frame (this_frame);
1392 /* This restriction could be lifted if other unwinders are known to
1393 compute the frame base in a way compatible with the DWARF
1395 if (! frame_unwinder_is (this_frame, &dwarf2_frame_unwind))
1396 error (_("can't compute CFA for this frame"));
1397 return get_frame_base (this_frame);
1400 const struct objfile_data *dwarf2_frame_objfile_data;
1403 read_1_byte (bfd *abfd, gdb_byte *buf)
1405 return bfd_get_8 (abfd, buf);
1409 read_4_bytes (bfd *abfd, gdb_byte *buf)
1411 return bfd_get_32 (abfd, buf);
1415 read_8_bytes (bfd *abfd, gdb_byte *buf)
1417 return bfd_get_64 (abfd, buf);
1421 read_unsigned_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
1424 unsigned int num_read;
1434 byte = bfd_get_8 (abfd, (bfd_byte *) buf);
1437 result |= ((byte & 0x7f) << shift);
1440 while (byte & 0x80);
1442 *bytes_read_ptr = num_read;
1448 read_signed_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
1452 unsigned int num_read;
1461 byte = bfd_get_8 (abfd, (bfd_byte *) buf);
1464 result |= ((byte & 0x7f) << shift);
1467 while (byte & 0x80);
1469 if (shift < 8 * sizeof (result) && (byte & 0x40))
1470 result |= -(((LONGEST)1) << shift);
1472 *bytes_read_ptr = num_read;
1478 read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
1482 result = bfd_get_32 (abfd, buf);
1483 if (result == 0xffffffff)
1485 result = bfd_get_64 (abfd, buf + 4);
1486 *bytes_read_ptr = 12;
1489 *bytes_read_ptr = 4;
1495 /* Pointer encoding helper functions. */
1497 /* GCC supports exception handling based on DWARF2 CFI. However, for
1498 technical reasons, it encodes addresses in its FDE's in a different
1499 way. Several "pointer encodings" are supported. The encoding
1500 that's used for a particular FDE is determined by the 'R'
1501 augmentation in the associated CIE. The argument of this
1502 augmentation is a single byte.
1504 The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a
1505 LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether
1506 the address is signed or unsigned. Bits 4, 5 and 6 encode how the
1507 address should be interpreted (absolute, relative to the current
1508 position in the FDE, ...). Bit 7, indicates that the address
1509 should be dereferenced. */
1512 encoding_for_size (unsigned int size)
1517 return DW_EH_PE_udata2;
1519 return DW_EH_PE_udata4;
1521 return DW_EH_PE_udata8;
1523 internal_error (__FILE__, __LINE__, _("Unsupported address size"));
1528 read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
1529 int ptr_len, const gdb_byte *buf,
1530 unsigned int *bytes_read_ptr,
1531 CORE_ADDR func_base)
1536 /* GCC currently doesn't generate DW_EH_PE_indirect encodings for
1538 if (encoding & DW_EH_PE_indirect)
1539 internal_error (__FILE__, __LINE__,
1540 _("Unsupported encoding: DW_EH_PE_indirect"));
1542 *bytes_read_ptr = 0;
1544 switch (encoding & 0x70)
1546 case DW_EH_PE_absptr:
1549 case DW_EH_PE_pcrel:
1550 base = bfd_get_section_vma (unit->abfd, unit->dwarf_frame_section);
1551 base += (buf - unit->dwarf_frame_buffer);
1553 case DW_EH_PE_datarel:
1556 case DW_EH_PE_textrel:
1559 case DW_EH_PE_funcrel:
1562 case DW_EH_PE_aligned:
1564 offset = buf - unit->dwarf_frame_buffer;
1565 if ((offset % ptr_len) != 0)
1567 *bytes_read_ptr = ptr_len - (offset % ptr_len);
1568 buf += *bytes_read_ptr;
1572 internal_error (__FILE__, __LINE__,
1573 _("Invalid or unsupported encoding"));
1576 if ((encoding & 0x07) == 0x00)
1578 encoding |= encoding_for_size (ptr_len);
1579 if (bfd_get_sign_extend_vma (unit->abfd))
1580 encoding |= DW_EH_PE_signed;
1583 switch (encoding & 0x0f)
1585 case DW_EH_PE_uleb128:
1588 const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
1590 *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf;
1591 return base + value;
1593 case DW_EH_PE_udata2:
1594 *bytes_read_ptr += 2;
1595 return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf));
1596 case DW_EH_PE_udata4:
1597 *bytes_read_ptr += 4;
1598 return (base + bfd_get_32 (unit->abfd, (bfd_byte *) buf));
1599 case DW_EH_PE_udata8:
1600 *bytes_read_ptr += 8;
1601 return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf));
1602 case DW_EH_PE_sleb128:
1605 const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
1607 *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf;
1608 return base + value;
1610 case DW_EH_PE_sdata2:
1611 *bytes_read_ptr += 2;
1612 return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf));
1613 case DW_EH_PE_sdata4:
1614 *bytes_read_ptr += 4;
1615 return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf));
1616 case DW_EH_PE_sdata8:
1617 *bytes_read_ptr += 8;
1618 return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf));
1620 internal_error (__FILE__, __LINE__,
1621 _("Invalid or unsupported encoding"));
1627 bsearch_cie_cmp (const void *key, const void *element)
1629 ULONGEST cie_pointer = *(ULONGEST *) key;
1630 struct dwarf2_cie *cie = *(struct dwarf2_cie **) element;
1632 if (cie_pointer == cie->cie_pointer)
1635 return (cie_pointer < cie->cie_pointer) ? -1 : 1;
1638 /* Find CIE with the given CIE_POINTER in CIE_TABLE. */
1639 static struct dwarf2_cie *
1640 find_cie (struct dwarf2_cie_table *cie_table, ULONGEST cie_pointer)
1642 struct dwarf2_cie **p_cie;
1644 /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to
1645 bsearch be non-NULL. */
1646 if (cie_table->entries == NULL)
1648 gdb_assert (cie_table->num_entries == 0);
1652 p_cie = bsearch (&cie_pointer, cie_table->entries, cie_table->num_entries,
1653 sizeof (cie_table->entries[0]), bsearch_cie_cmp);
1659 /* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */
1661 add_cie (struct dwarf2_cie_table *cie_table, struct dwarf2_cie *cie)
1663 const int n = cie_table->num_entries;
1666 || cie_table->entries[n - 1]->cie_pointer < cie->cie_pointer);
1668 cie_table->entries =
1669 xrealloc (cie_table->entries, (n + 1) * sizeof (cie_table->entries[0]));
1670 cie_table->entries[n] = cie;
1671 cie_table->num_entries = n + 1;
1675 bsearch_fde_cmp (const void *key, const void *element)
1677 CORE_ADDR seek_pc = *(CORE_ADDR *) key;
1678 struct dwarf2_fde *fde = *(struct dwarf2_fde **) element;
1680 if (seek_pc < fde->initial_location)
1682 if (seek_pc < fde->initial_location + fde->address_range)
1687 /* Find the FDE for *PC. Return a pointer to the FDE, and store the
1688 inital location associated with it into *PC. */
1690 static struct dwarf2_fde *
1691 dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset)
1693 struct objfile *objfile;
1695 ALL_OBJFILES (objfile)
1697 struct dwarf2_fde_table *fde_table;
1698 struct dwarf2_fde **p_fde;
1702 fde_table = objfile_data (objfile, dwarf2_frame_objfile_data);
1703 if (fde_table == NULL)
1705 dwarf2_build_frame_info (objfile);
1706 fde_table = objfile_data (objfile, dwarf2_frame_objfile_data);
1708 gdb_assert (fde_table != NULL);
1710 if (fde_table->num_entries == 0)
1713 gdb_assert (objfile->section_offsets);
1714 offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
1716 gdb_assert (fde_table->num_entries > 0);
1717 if (*pc < offset + fde_table->entries[0]->initial_location)
1720 seek_pc = *pc - offset;
1721 p_fde = bsearch (&seek_pc, fde_table->entries, fde_table->num_entries,
1722 sizeof (fde_table->entries[0]), bsearch_fde_cmp);
1725 *pc = (*p_fde)->initial_location + offset;
1727 *out_offset = offset;
1734 /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */
1736 add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde)
1738 if (fde->address_range == 0)
1739 /* Discard useless FDEs. */
1742 fde_table->num_entries += 1;
1743 fde_table->entries =
1744 xrealloc (fde_table->entries,
1745 fde_table->num_entries * sizeof (fde_table->entries[0]));
1746 fde_table->entries[fde_table->num_entries - 1] = fde;
1749 #ifdef CC_HAS_LONG_LONG
1750 #define DW64_CIE_ID 0xffffffffffffffffULL
1752 #define DW64_CIE_ID ~0
1755 static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start,
1757 struct dwarf2_cie_table *cie_table,
1758 struct dwarf2_fde_table *fde_table);
1760 /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise
1761 the next byte to be processed. */
1763 decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p,
1764 struct dwarf2_cie_table *cie_table,
1765 struct dwarf2_fde_table *fde_table)
1767 struct gdbarch *gdbarch = get_objfile_arch (unit->objfile);
1768 gdb_byte *buf, *end;
1770 unsigned int bytes_read;
1773 ULONGEST cie_pointer;
1776 length = read_initial_length (unit->abfd, buf, &bytes_read);
1780 /* Are we still within the section? */
1781 if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size)
1787 /* Distinguish between 32 and 64-bit encoded frame info. */
1788 dwarf64_p = (bytes_read == 12);
1790 /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */
1794 cie_id = DW64_CIE_ID;
1800 cie_pointer = read_8_bytes (unit->abfd, buf);
1805 cie_pointer = read_4_bytes (unit->abfd, buf);
1809 if (cie_pointer == cie_id)
1811 /* This is a CIE. */
1812 struct dwarf2_cie *cie;
1814 unsigned int cie_version;
1816 /* Record the offset into the .debug_frame section of this CIE. */
1817 cie_pointer = start - unit->dwarf_frame_buffer;
1819 /* Check whether we've already read it. */
1820 if (find_cie (cie_table, cie_pointer))
1823 cie = (struct dwarf2_cie *)
1824 obstack_alloc (&unit->objfile->objfile_obstack,
1825 sizeof (struct dwarf2_cie));
1826 cie->initial_instructions = NULL;
1827 cie->cie_pointer = cie_pointer;
1829 /* The encoding for FDE's in a normal .debug_frame section
1830 depends on the target address size. */
1831 cie->encoding = DW_EH_PE_absptr;
1833 /* We'll determine the final value later, but we need to
1834 initialize it conservatively. */
1835 cie->signal_frame = 0;
1837 /* Check version number. */
1838 cie_version = read_1_byte (unit->abfd, buf);
1839 if (cie_version != 1 && cie_version != 3 && cie_version != 4)
1841 cie->version = cie_version;
1844 /* Interpret the interesting bits of the augmentation. */
1845 cie->augmentation = augmentation = (char *) buf;
1846 buf += (strlen (augmentation) + 1);
1848 /* Ignore armcc augmentations. We only use them for quirks,
1849 and that doesn't happen until later. */
1850 if (strncmp (augmentation, "armcc", 5) == 0)
1851 augmentation += strlen (augmentation);
1853 /* The GCC 2.x "eh" augmentation has a pointer immediately
1854 following the augmentation string, so it must be handled
1856 if (augmentation[0] == 'e' && augmentation[1] == 'h')
1859 buf += gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
1863 if (cie->version >= 4)
1865 /* FIXME: check that this is the same as from the CU header. */
1866 cie->addr_size = read_1_byte (unit->abfd, buf);
1868 cie->segment_size = read_1_byte (unit->abfd, buf);
1873 cie->addr_size = gdbarch_dwarf2_addr_size (gdbarch);
1874 cie->segment_size = 0;
1876 /* Address values in .eh_frame sections are defined to have the
1877 target's pointer size. Watchout: This breaks frame info for
1878 targets with pointer size < address size, unless a .debug_frame
1879 section exists as well. */
1881 cie->ptr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
1883 cie->ptr_size = cie->addr_size;
1885 cie->code_alignment_factor =
1886 read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
1889 cie->data_alignment_factor =
1890 read_signed_leb128 (unit->abfd, buf, &bytes_read);
1893 if (cie_version == 1)
1895 cie->return_address_register = read_1_byte (unit->abfd, buf);
1899 cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf,
1901 cie->return_address_register
1902 = dwarf2_frame_adjust_regnum (gdbarch,
1903 cie->return_address_register,
1908 cie->saw_z_augmentation = (*augmentation == 'z');
1909 if (cie->saw_z_augmentation)
1913 length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
1917 cie->initial_instructions = buf + length;
1921 while (*augmentation)
1923 /* "L" indicates a byte showing how the LSDA pointer is encoded. */
1924 if (*augmentation == 'L')
1931 /* "R" indicates a byte indicating how FDE addresses are encoded. */
1932 else if (*augmentation == 'R')
1934 cie->encoding = *buf++;
1938 /* "P" indicates a personality routine in the CIE augmentation. */
1939 else if (*augmentation == 'P')
1941 /* Skip. Avoid indirection since we throw away the result. */
1942 gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect;
1943 read_encoded_value (unit, encoding, cie->ptr_size,
1944 buf, &bytes_read, 0);
1949 /* "S" indicates a signal frame, such that the return
1950 address must not be decremented to locate the call frame
1951 info for the previous frame; it might even be the first
1952 instruction of a function, so decrementing it would take
1953 us to a different function. */
1954 else if (*augmentation == 'S')
1956 cie->signal_frame = 1;
1960 /* Otherwise we have an unknown augmentation. Assume that either
1961 there is no augmentation data, or we saw a 'z' prefix. */
1964 if (cie->initial_instructions)
1965 buf = cie->initial_instructions;
1970 cie->initial_instructions = buf;
1974 add_cie (cie_table, cie);
1978 /* This is a FDE. */
1979 struct dwarf2_fde *fde;
1981 /* In an .eh_frame section, the CIE pointer is the delta between the
1982 address within the FDE where the CIE pointer is stored and the
1983 address of the CIE. Convert it to an offset into the .eh_frame
1987 cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer;
1988 cie_pointer -= (dwarf64_p ? 8 : 4);
1991 /* In either case, validate the result is still within the section. */
1992 if (cie_pointer >= unit->dwarf_frame_size)
1995 fde = (struct dwarf2_fde *)
1996 obstack_alloc (&unit->objfile->objfile_obstack,
1997 sizeof (struct dwarf2_fde));
1998 fde->cie = find_cie (cie_table, cie_pointer);
1999 if (fde->cie == NULL)
2001 decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer,
2002 eh_frame_p, cie_table, fde_table);
2003 fde->cie = find_cie (cie_table, cie_pointer);
2006 gdb_assert (fde->cie != NULL);
2008 fde->initial_location =
2009 read_encoded_value (unit, fde->cie->encoding, fde->cie->ptr_size,
2010 buf, &bytes_read, 0);
2013 fde->address_range =
2014 read_encoded_value (unit, fde->cie->encoding & 0x0f,
2015 fde->cie->ptr_size, buf, &bytes_read, 0);
2018 /* A 'z' augmentation in the CIE implies the presence of an
2019 augmentation field in the FDE as well. The only thing known
2020 to be in here at present is the LSDA entry for EH. So we
2021 can skip the whole thing. */
2022 if (fde->cie->saw_z_augmentation)
2026 length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
2027 buf += bytes_read + length;
2032 fde->instructions = buf;
2035 fde->eh_frame_p = eh_frame_p;
2037 add_fde (fde_table, fde);
2043 /* Read a CIE or FDE in BUF and decode it. */
2045 decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p,
2046 struct dwarf2_cie_table *cie_table,
2047 struct dwarf2_fde_table *fde_table)
2049 enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
2051 ptrdiff_t start_offset;
2055 ret = decode_frame_entry_1 (unit, start, eh_frame_p,
2056 cie_table, fde_table);
2060 /* We have corrupt input data of some form. */
2062 /* ??? Try, weakly, to work around compiler/assembler/linker bugs
2063 and mismatches wrt padding and alignment of debug sections. */
2064 /* Note that there is no requirement in the standard for any
2065 alignment at all in the frame unwind sections. Testing for
2066 alignment before trying to interpret data would be incorrect.
2068 However, GCC traditionally arranged for frame sections to be
2069 sized such that the FDE length and CIE fields happen to be
2070 aligned (in theory, for performance). This, unfortunately,
2071 was done with .align directives, which had the side effect of
2072 forcing the section to be aligned by the linker.
2074 This becomes a problem when you have some other producer that
2075 creates frame sections that are not as strictly aligned. That
2076 produces a hole in the frame info that gets filled by the
2079 The GCC behaviour is arguably a bug, but it's effectively now
2080 part of the ABI, so we're now stuck with it, at least at the
2081 object file level. A smart linker may decide, in the process
2082 of compressing duplicate CIE information, that it can rewrite
2083 the entire output section without this extra padding. */
2085 start_offset = start - unit->dwarf_frame_buffer;
2086 if (workaround < ALIGN4 && (start_offset & 3) != 0)
2088 start += 4 - (start_offset & 3);
2089 workaround = ALIGN4;
2092 if (workaround < ALIGN8 && (start_offset & 7) != 0)
2094 start += 8 - (start_offset & 7);
2095 workaround = ALIGN8;
2099 /* Nothing left to try. Arrange to return as if we've consumed
2100 the entire input section. Hopefully we'll get valid info from
2101 the other of .debug_frame/.eh_frame. */
2103 ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size;
2113 complaint (&symfile_complaints, _("\
2114 Corrupt data in %s:%s; align 4 workaround apparently succeeded"),
2115 unit->dwarf_frame_section->owner->filename,
2116 unit->dwarf_frame_section->name);
2120 complaint (&symfile_complaints, _("\
2121 Corrupt data in %s:%s; align 8 workaround apparently succeeded"),
2122 unit->dwarf_frame_section->owner->filename,
2123 unit->dwarf_frame_section->name);
2127 complaint (&symfile_complaints,
2128 _("Corrupt data in %s:%s"),
2129 unit->dwarf_frame_section->owner->filename,
2130 unit->dwarf_frame_section->name);
2138 /* Imported from dwarf2read.c. */
2139 extern void dwarf2_get_section_info (struct objfile *, const char *,
2140 asection **, gdb_byte **,
2144 qsort_fde_cmp (const void *a, const void *b)
2146 struct dwarf2_fde *aa = *(struct dwarf2_fde **)a;
2147 struct dwarf2_fde *bb = *(struct dwarf2_fde **)b;
2149 if (aa->initial_location == bb->initial_location)
2151 if (aa->address_range != bb->address_range
2152 && aa->eh_frame_p == 0 && bb->eh_frame_p == 0)
2153 /* Linker bug, e.g. gold/10400.
2154 Work around it by keeping stable sort order. */
2155 return (a < b) ? -1 : 1;
2157 /* Put eh_frame entries after debug_frame ones. */
2158 return aa->eh_frame_p - bb->eh_frame_p;
2161 return (aa->initial_location < bb->initial_location) ? -1 : 1;
2165 dwarf2_build_frame_info (struct objfile *objfile)
2167 struct comp_unit *unit;
2168 gdb_byte *frame_ptr;
2169 struct dwarf2_cie_table cie_table;
2170 struct dwarf2_fde_table fde_table;
2171 struct dwarf2_fde_table *fde_table2;
2173 cie_table.num_entries = 0;
2174 cie_table.entries = NULL;
2176 fde_table.num_entries = 0;
2177 fde_table.entries = NULL;
2179 /* Build a minimal decoding of the DWARF2 compilation unit. */
2180 unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack,
2181 sizeof (struct comp_unit));
2182 unit->abfd = objfile->obfd;
2183 unit->objfile = objfile;
2187 dwarf2_get_section_info (objfile, ".eh_frame",
2188 &unit->dwarf_frame_section,
2189 &unit->dwarf_frame_buffer,
2190 &unit->dwarf_frame_size);
2191 if (unit->dwarf_frame_size)
2193 asection *got, *txt;
2195 /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base
2196 that is used for the i386/amd64 target, which currently is
2197 the only target in GCC that supports/uses the
2198 DW_EH_PE_datarel encoding. */
2199 got = bfd_get_section_by_name (unit->abfd, ".got");
2201 unit->dbase = got->vma;
2203 /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64
2205 txt = bfd_get_section_by_name (unit->abfd, ".text");
2207 unit->tbase = txt->vma;
2209 frame_ptr = unit->dwarf_frame_buffer;
2210 while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size)
2211 frame_ptr = decode_frame_entry (unit, frame_ptr, 1,
2212 &cie_table, &fde_table);
2214 if (cie_table.num_entries != 0)
2216 /* Reinit cie_table: debug_frame has different CIEs. */
2217 xfree (cie_table.entries);
2218 cie_table.num_entries = 0;
2219 cie_table.entries = NULL;
2223 dwarf2_get_section_info (objfile, ".debug_frame",
2224 &unit->dwarf_frame_section,
2225 &unit->dwarf_frame_buffer,
2226 &unit->dwarf_frame_size);
2227 if (unit->dwarf_frame_size)
2229 frame_ptr = unit->dwarf_frame_buffer;
2230 while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size)
2231 frame_ptr = decode_frame_entry (unit, frame_ptr, 0,
2232 &cie_table, &fde_table);
2235 /* Discard the cie_table, it is no longer needed. */
2236 if (cie_table.num_entries != 0)
2238 xfree (cie_table.entries);
2239 cie_table.entries = NULL; /* Paranoia. */
2240 cie_table.num_entries = 0; /* Paranoia. */
2243 /* Copy fde_table to obstack: it is needed at runtime. */
2244 fde_table2 = (struct dwarf2_fde_table *)
2245 obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2));
2247 if (fde_table.num_entries == 0)
2249 fde_table2->entries = NULL;
2250 fde_table2->num_entries = 0;
2254 struct dwarf2_fde *fde_prev = NULL;
2255 struct dwarf2_fde *first_non_zero_fde = NULL;
2258 /* Prepare FDE table for lookups. */
2259 qsort (fde_table.entries, fde_table.num_entries,
2260 sizeof (fde_table.entries[0]), qsort_fde_cmp);
2262 /* Check for leftovers from --gc-sections. The GNU linker sets
2263 the relevant symbols to zero, but doesn't zero the FDE *end*
2264 ranges because there's no relocation there. It's (offset,
2265 length), not (start, end). On targets where address zero is
2266 just another valid address this can be a problem, since the
2267 FDEs appear to be non-empty in the output --- we could pick
2268 out the wrong FDE. To work around this, when overlaps are
2269 detected, we prefer FDEs that do not start at zero.
2271 Start by finding the first FDE with non-zero start. Below
2272 we'll discard all FDEs that start at zero and overlap this
2274 for (i = 0; i < fde_table.num_entries; i++)
2276 struct dwarf2_fde *fde = fde_table.entries[i];
2278 if (fde->initial_location != 0)
2280 first_non_zero_fde = fde;
2285 /* Since we'll be doing bsearch, squeeze out identical (except
2286 for eh_frame_p) fde entries so bsearch result is predictable.
2287 Also discard leftovers from --gc-sections. */
2288 fde_table2->num_entries = 0;
2289 for (i = 0; i < fde_table.num_entries; i++)
2291 struct dwarf2_fde *fde = fde_table.entries[i];
2293 if (fde->initial_location == 0
2294 && first_non_zero_fde != NULL
2295 && (first_non_zero_fde->initial_location
2296 < fde->initial_location + fde->address_range))
2299 if (fde_prev != NULL
2300 && fde_prev->initial_location == fde->initial_location)
2303 obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i],
2304 sizeof (fde_table.entries[0]));
2305 ++fde_table2->num_entries;
2308 fde_table2->entries = obstack_finish (&objfile->objfile_obstack);
2310 /* Discard the original fde_table. */
2311 xfree (fde_table.entries);
2314 set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2);
2317 /* Provide a prototype to silence -Wmissing-prototypes. */
2318 void _initialize_dwarf2_frame (void);
2321 _initialize_dwarf2_frame (void)
2323 dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init);
2324 dwarf2_frame_objfile_data = register_objfile_data ();