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"
43 #include "exceptions.h"
47 /* Call Frame Information (CFI). */
49 /* Common Information Entry (CIE). */
53 /* Computation Unit for this CIE. */
54 struct comp_unit
*unit
;
56 /* Offset into the .debug_frame section where this CIE was found.
57 Used to identify this CIE. */
60 /* Constant that is factored out of all advance location
62 ULONGEST code_alignment_factor
;
64 /* Constants that is factored out of all offset instructions. */
65 LONGEST data_alignment_factor
;
67 /* Return address column. */
68 ULONGEST return_address_register
;
70 /* Instruction sequence to initialize a register set. */
71 gdb_byte
*initial_instructions
;
74 /* Saved augmentation, in case it's needed later. */
77 /* Encoding of addresses. */
80 /* Target address size in bytes. */
83 /* Target pointer size in bytes. */
86 /* True if a 'z' augmentation existed. */
87 unsigned char saw_z_augmentation
;
89 /* True if an 'S' augmentation existed. */
90 unsigned char signal_frame
;
92 /* The version recorded in the CIE. */
93 unsigned char version
;
95 /* The segment size. */
96 unsigned char segment_size
;
99 struct dwarf2_cie_table
102 struct dwarf2_cie
**entries
;
105 /* Frame Description Entry (FDE). */
109 /* CIE for this FDE. */
110 struct dwarf2_cie
*cie
;
112 /* First location associated with this FDE. */
113 CORE_ADDR initial_location
;
115 /* Number of bytes of program instructions described by this FDE. */
116 CORE_ADDR address_range
;
118 /* Instruction sequence. */
119 gdb_byte
*instructions
;
122 /* True if this FDE is read from a .eh_frame instead of a .debug_frame
124 unsigned char eh_frame_p
;
127 struct dwarf2_fde_table
130 struct dwarf2_fde
**entries
;
133 /* A minimal decoding of DWARF2 compilation units. We only decode
134 what's needed to get to the call frame information. */
138 /* Keep the bfd convenient. */
141 struct objfile
*objfile
;
143 /* Pointer to the .debug_frame section loaded into memory. */
144 gdb_byte
*dwarf_frame_buffer
;
146 /* Length of the loaded .debug_frame section. */
147 bfd_size_type dwarf_frame_size
;
149 /* Pointer to the .debug_frame section. */
150 asection
*dwarf_frame_section
;
152 /* Base for DW_EH_PE_datarel encodings. */
155 /* Base for DW_EH_PE_textrel encodings. */
159 static struct dwarf2_fde
*dwarf2_frame_find_fde (CORE_ADDR
*pc
,
160 CORE_ADDR
*out_offset
);
162 static int dwarf2_frame_adjust_regnum (struct gdbarch
*gdbarch
, int regnum
,
165 static CORE_ADDR
read_encoded_value (struct comp_unit
*unit
, gdb_byte encoding
,
166 int ptr_len
, const gdb_byte
*buf
,
167 unsigned int *bytes_read_ptr
,
168 CORE_ADDR func_base
);
171 /* Structure describing a frame state. */
173 struct dwarf2_frame_state
175 /* Each register save state can be described in terms of a CFA slot,
176 another register, or a location expression. */
177 struct dwarf2_frame_state_reg_info
179 struct dwarf2_frame_state_reg
*reg
;
189 const gdb_byte
*cfa_exp
;
191 /* Used to implement DW_CFA_remember_state. */
192 struct dwarf2_frame_state_reg_info
*prev
;
195 /* The PC described by the current frame state. */
198 /* Initial register set from the CIE.
199 Used to implement DW_CFA_restore. */
200 struct dwarf2_frame_state_reg_info initial
;
202 /* The information we care about from the CIE. */
205 ULONGEST retaddr_column
;
207 /* Flags for known producer quirks. */
209 /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
210 and DW_CFA_def_cfa_offset takes a factored offset. */
211 int armcc_cfa_offsets_sf
;
213 /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
214 the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
215 int armcc_cfa_offsets_reversed
;
218 /* Store the length the expression for the CFA in the `cfa_reg' field,
219 which is unused in that case. */
220 #define cfa_exp_len cfa_reg
222 /* Assert that the register set RS is large enough to store gdbarch_num_regs
223 columns. If necessary, enlarge the register set. */
226 dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info
*rs
,
229 size_t size
= sizeof (struct dwarf2_frame_state_reg
);
231 if (num_regs
<= rs
->num_regs
)
234 rs
->reg
= (struct dwarf2_frame_state_reg
*)
235 xrealloc (rs
->reg
, num_regs
* size
);
237 /* Initialize newly allocated registers. */
238 memset (rs
->reg
+ rs
->num_regs
, 0, (num_regs
- rs
->num_regs
) * size
);
239 rs
->num_regs
= num_regs
;
242 /* Copy the register columns in register set RS into newly allocated
243 memory and return a pointer to this newly created copy. */
245 static struct dwarf2_frame_state_reg
*
246 dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info
*rs
)
248 size_t size
= rs
->num_regs
* sizeof (struct dwarf2_frame_state_reg
);
249 struct dwarf2_frame_state_reg
*reg
;
251 reg
= (struct dwarf2_frame_state_reg
*) xmalloc (size
);
252 memcpy (reg
, rs
->reg
, size
);
257 /* Release the memory allocated to register set RS. */
260 dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info
*rs
)
264 dwarf2_frame_state_free_regs (rs
->prev
);
271 /* Release the memory allocated to the frame state FS. */
274 dwarf2_frame_state_free (void *p
)
276 struct dwarf2_frame_state
*fs
= p
;
278 dwarf2_frame_state_free_regs (fs
->initial
.prev
);
279 dwarf2_frame_state_free_regs (fs
->regs
.prev
);
280 xfree (fs
->initial
.reg
);
281 xfree (fs
->regs
.reg
);
286 /* Helper functions for execute_stack_op. */
289 read_reg (void *baton
, int reg
)
291 struct frame_info
*this_frame
= (struct frame_info
*) baton
;
292 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
296 regnum
= gdbarch_dwarf2_reg_to_regnum (gdbarch
, reg
);
298 buf
= alloca (register_size (gdbarch
, regnum
));
299 get_frame_register (this_frame
, regnum
, buf
);
301 /* Convert the register to an integer. This returns a LONGEST
302 rather than a CORE_ADDR, but unpack_pointer does the same thing
303 under the covers, and this makes more sense for non-pointer
304 registers. Maybe read_reg and the associated interfaces should
305 deal with "struct value" instead of CORE_ADDR. */
306 return unpack_long (register_type (gdbarch
, regnum
), buf
);
310 read_mem (void *baton
, gdb_byte
*buf
, CORE_ADDR addr
, size_t len
)
312 read_memory (addr
, buf
, len
);
316 no_get_frame_base (void *baton
, const gdb_byte
**start
, size_t *length
)
318 internal_error (__FILE__
, __LINE__
,
319 _("Support for DW_OP_fbreg is unimplemented"));
322 /* Helper function for execute_stack_op. */
325 no_get_frame_cfa (void *baton
)
327 internal_error (__FILE__
, __LINE__
,
328 _("Support for DW_OP_call_frame_cfa is unimplemented"));
331 /* Helper function for execute_stack_op. */
334 no_get_frame_pc (void *baton
)
336 internal_error (__FILE__
, __LINE__
, _("\
337 Support for DW_OP_GNU_implicit_pointer is unimplemented"));
341 no_get_tls_address (void *baton
, CORE_ADDR offset
)
343 internal_error (__FILE__
, __LINE__
, _("\
344 Support for DW_OP_GNU_push_tls_address is unimplemented"));
347 /* Helper function for execute_stack_op. */
350 no_dwarf_call (struct dwarf_expr_context
*ctx
, size_t die_offset
)
352 internal_error (__FILE__
, __LINE__
,
353 _("Support for DW_OP_call* is invalid in CFI"));
356 /* Execute the required actions for both the DW_CFA_restore and
357 DW_CFA_restore_extended instructions. */
359 dwarf2_restore_rule (struct gdbarch
*gdbarch
, ULONGEST reg_num
,
360 struct dwarf2_frame_state
*fs
, int eh_frame_p
)
364 gdb_assert (fs
->initial
.reg
);
365 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg_num
, eh_frame_p
);
366 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
368 /* Check if this register was explicitly initialized in the
369 CIE initial instructions. If not, default the rule to
371 if (reg
< fs
->initial
.num_regs
)
372 fs
->regs
.reg
[reg
] = fs
->initial
.reg
[reg
];
374 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_UNSPECIFIED
;
376 if (fs
->regs
.reg
[reg
].how
== DWARF2_FRAME_REG_UNSPECIFIED
)
377 complaint (&symfile_complaints
, _("\
378 incomplete CFI data; DW_CFA_restore unspecified\n\
379 register %s (#%d) at %s"),
380 gdbarch_register_name
381 (gdbarch
, gdbarch_dwarf2_reg_to_regnum (gdbarch
, reg
)),
382 gdbarch_dwarf2_reg_to_regnum (gdbarch
, reg
),
383 paddress (gdbarch
, fs
->pc
));
387 execute_stack_op (const gdb_byte
*exp
, ULONGEST len
, int addr_size
,
388 CORE_ADDR offset
, struct frame_info
*this_frame
,
389 CORE_ADDR initial
, int initial_in_stack_memory
)
391 struct dwarf_expr_context
*ctx
;
393 struct cleanup
*old_chain
;
395 ctx
= new_dwarf_expr_context ();
396 old_chain
= make_cleanup_free_dwarf_expr_context (ctx
);
398 ctx
->gdbarch
= get_frame_arch (this_frame
);
399 ctx
->addr_size
= addr_size
;
400 ctx
->offset
= offset
;
401 ctx
->baton
= this_frame
;
402 ctx
->read_reg
= read_reg
;
403 ctx
->read_mem
= read_mem
;
404 ctx
->get_frame_base
= no_get_frame_base
;
405 ctx
->get_frame_cfa
= no_get_frame_cfa
;
406 ctx
->get_frame_pc
= no_get_frame_pc
;
407 ctx
->get_tls_address
= no_get_tls_address
;
408 ctx
->dwarf_call
= no_dwarf_call
;
410 dwarf_expr_push (ctx
, initial
, initial_in_stack_memory
);
411 dwarf_expr_eval (ctx
, exp
, len
);
413 if (ctx
->location
== DWARF_VALUE_MEMORY
)
414 result
= dwarf_expr_fetch_address (ctx
, 0);
415 else if (ctx
->location
== DWARF_VALUE_REGISTER
)
416 result
= read_reg (this_frame
, dwarf_expr_fetch (ctx
, 0));
419 /* This is actually invalid DWARF, but if we ever do run across
420 it somehow, we might as well support it. So, instead, report
421 it as unimplemented. */
423 Not implemented: computing unwound register using explicit value operator"));
426 do_cleanups (old_chain
);
433 execute_cfa_program (struct dwarf2_fde
*fde
, const gdb_byte
*insn_ptr
,
434 const gdb_byte
*insn_end
, struct gdbarch
*gdbarch
,
435 CORE_ADDR pc
, struct dwarf2_frame_state
*fs
)
437 int eh_frame_p
= fde
->eh_frame_p
;
439 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
441 while (insn_ptr
< insn_end
&& fs
->pc
<= pc
)
443 gdb_byte insn
= *insn_ptr
++;
447 if ((insn
& 0xc0) == DW_CFA_advance_loc
)
448 fs
->pc
+= (insn
& 0x3f) * fs
->code_align
;
449 else if ((insn
& 0xc0) == DW_CFA_offset
)
452 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
453 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
454 offset
= utmp
* fs
->data_align
;
455 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
456 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_OFFSET
;
457 fs
->regs
.reg
[reg
].loc
.offset
= offset
;
459 else if ((insn
& 0xc0) == DW_CFA_restore
)
462 dwarf2_restore_rule (gdbarch
, reg
, fs
, eh_frame_p
);
469 fs
->pc
= read_encoded_value (fde
->cie
->unit
, fde
->cie
->encoding
,
470 fde
->cie
->ptr_size
, insn_ptr
,
471 &bytes_read
, fde
->initial_location
);
472 /* Apply the objfile offset for relocatable objects. */
473 fs
->pc
+= ANOFFSET (fde
->cie
->unit
->objfile
->section_offsets
,
474 SECT_OFF_TEXT (fde
->cie
->unit
->objfile
));
475 insn_ptr
+= bytes_read
;
478 case DW_CFA_advance_loc1
:
479 utmp
= extract_unsigned_integer (insn_ptr
, 1, byte_order
);
480 fs
->pc
+= utmp
* fs
->code_align
;
483 case DW_CFA_advance_loc2
:
484 utmp
= extract_unsigned_integer (insn_ptr
, 2, byte_order
);
485 fs
->pc
+= utmp
* fs
->code_align
;
488 case DW_CFA_advance_loc4
:
489 utmp
= extract_unsigned_integer (insn_ptr
, 4, byte_order
);
490 fs
->pc
+= utmp
* fs
->code_align
;
494 case DW_CFA_offset_extended
:
495 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
496 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
497 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
498 offset
= utmp
* fs
->data_align
;
499 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
500 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_OFFSET
;
501 fs
->regs
.reg
[reg
].loc
.offset
= offset
;
504 case DW_CFA_restore_extended
:
505 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
506 dwarf2_restore_rule (gdbarch
, reg
, fs
, eh_frame_p
);
509 case DW_CFA_undefined
:
510 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
511 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
512 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
513 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_UNDEFINED
;
516 case DW_CFA_same_value
:
517 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
518 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
519 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
520 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAME_VALUE
;
523 case DW_CFA_register
:
524 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
525 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
526 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
527 utmp
= dwarf2_frame_adjust_regnum (gdbarch
, utmp
, eh_frame_p
);
528 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
529 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_REG
;
530 fs
->regs
.reg
[reg
].loc
.reg
= utmp
;
533 case DW_CFA_remember_state
:
535 struct dwarf2_frame_state_reg_info
*new_rs
;
537 new_rs
= XMALLOC (struct dwarf2_frame_state_reg_info
);
539 fs
->regs
.reg
= dwarf2_frame_state_copy_regs (&fs
->regs
);
540 fs
->regs
.prev
= new_rs
;
544 case DW_CFA_restore_state
:
546 struct dwarf2_frame_state_reg_info
*old_rs
= fs
->regs
.prev
;
550 complaint (&symfile_complaints
, _("\
551 bad CFI data; mismatched DW_CFA_restore_state at %s"),
552 paddress (gdbarch
, fs
->pc
));
556 xfree (fs
->regs
.reg
);
564 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &fs
->regs
.cfa_reg
);
565 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
567 if (fs
->armcc_cfa_offsets_sf
)
568 utmp
*= fs
->data_align
;
570 fs
->regs
.cfa_offset
= utmp
;
571 fs
->regs
.cfa_how
= CFA_REG_OFFSET
;
574 case DW_CFA_def_cfa_register
:
575 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &fs
->regs
.cfa_reg
);
576 fs
->regs
.cfa_reg
= dwarf2_frame_adjust_regnum (gdbarch
,
579 fs
->regs
.cfa_how
= CFA_REG_OFFSET
;
582 case DW_CFA_def_cfa_offset
:
583 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
585 if (fs
->armcc_cfa_offsets_sf
)
586 utmp
*= fs
->data_align
;
588 fs
->regs
.cfa_offset
= utmp
;
589 /* cfa_how deliberately not set. */
595 case DW_CFA_def_cfa_expression
:
596 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
,
597 &fs
->regs
.cfa_exp_len
);
598 fs
->regs
.cfa_exp
= insn_ptr
;
599 fs
->regs
.cfa_how
= CFA_EXP
;
600 insn_ptr
+= fs
->regs
.cfa_exp_len
;
603 case DW_CFA_expression
:
604 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
605 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
606 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
607 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
608 fs
->regs
.reg
[reg
].loc
.exp
= insn_ptr
;
609 fs
->regs
.reg
[reg
].exp_len
= utmp
;
610 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_EXP
;
614 case DW_CFA_offset_extended_sf
:
615 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
616 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
617 insn_ptr
= read_sleb128 (insn_ptr
, insn_end
, &offset
);
618 offset
*= fs
->data_align
;
619 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
620 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_OFFSET
;
621 fs
->regs
.reg
[reg
].loc
.offset
= offset
;
624 case DW_CFA_val_offset
:
625 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
626 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
627 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
628 offset
= utmp
* fs
->data_align
;
629 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_VAL_OFFSET
;
630 fs
->regs
.reg
[reg
].loc
.offset
= offset
;
633 case DW_CFA_val_offset_sf
:
634 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
635 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
636 insn_ptr
= read_sleb128 (insn_ptr
, insn_end
, &offset
);
637 offset
*= fs
->data_align
;
638 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_VAL_OFFSET
;
639 fs
->regs
.reg
[reg
].loc
.offset
= offset
;
642 case DW_CFA_val_expression
:
643 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
644 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
645 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
646 fs
->regs
.reg
[reg
].loc
.exp
= insn_ptr
;
647 fs
->regs
.reg
[reg
].exp_len
= utmp
;
648 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_VAL_EXP
;
652 case DW_CFA_def_cfa_sf
:
653 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &fs
->regs
.cfa_reg
);
654 fs
->regs
.cfa_reg
= dwarf2_frame_adjust_regnum (gdbarch
,
657 insn_ptr
= read_sleb128 (insn_ptr
, insn_end
, &offset
);
658 fs
->regs
.cfa_offset
= offset
* fs
->data_align
;
659 fs
->regs
.cfa_how
= CFA_REG_OFFSET
;
662 case DW_CFA_def_cfa_offset_sf
:
663 insn_ptr
= read_sleb128 (insn_ptr
, insn_end
, &offset
);
664 fs
->regs
.cfa_offset
= offset
* fs
->data_align
;
665 /* cfa_how deliberately not set. */
668 case DW_CFA_GNU_window_save
:
669 /* This is SPARC-specific code, and contains hard-coded
670 constants for the register numbering scheme used by
671 GCC. Rather than having a architecture-specific
672 operation that's only ever used by a single
673 architecture, we provide the implementation here.
674 Incidentally that's what GCC does too in its
677 int size
= register_size (gdbarch
, 0);
679 dwarf2_frame_state_alloc_regs (&fs
->regs
, 32);
680 for (reg
= 8; reg
< 16; reg
++)
682 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_REG
;
683 fs
->regs
.reg
[reg
].loc
.reg
= reg
+ 16;
685 for (reg
= 16; reg
< 32; reg
++)
687 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_OFFSET
;
688 fs
->regs
.reg
[reg
].loc
.offset
= (reg
- 16) * size
;
693 case DW_CFA_GNU_args_size
:
695 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &utmp
);
698 case DW_CFA_GNU_negative_offset_extended
:
699 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, ®
);
700 reg
= dwarf2_frame_adjust_regnum (gdbarch
, reg
, eh_frame_p
);
701 insn_ptr
= read_uleb128 (insn_ptr
, insn_end
, &offset
);
702 offset
*= fs
->data_align
;
703 dwarf2_frame_state_alloc_regs (&fs
->regs
, reg
+ 1);
704 fs
->regs
.reg
[reg
].how
= DWARF2_FRAME_REG_SAVED_OFFSET
;
705 fs
->regs
.reg
[reg
].loc
.offset
= -offset
;
709 internal_error (__FILE__
, __LINE__
,
710 _("Unknown CFI encountered."));
715 /* Don't allow remember/restore between CIE and FDE programs. */
716 dwarf2_frame_state_free_regs (fs
->regs
.prev
);
717 fs
->regs
.prev
= NULL
;
721 /* Architecture-specific operations. */
723 /* Per-architecture data key. */
724 static struct gdbarch_data
*dwarf2_frame_data
;
726 struct dwarf2_frame_ops
728 /* Pre-initialize the register state REG for register REGNUM. */
729 void (*init_reg
) (struct gdbarch
*, int, struct dwarf2_frame_state_reg
*,
730 struct frame_info
*);
732 /* Check whether the THIS_FRAME is a signal trampoline. */
733 int (*signal_frame_p
) (struct gdbarch
*, struct frame_info
*);
735 /* Convert .eh_frame register number to DWARF register number, or
736 adjust .debug_frame register number. */
737 int (*adjust_regnum
) (struct gdbarch
*, int, int);
740 /* Default architecture-specific register state initialization
744 dwarf2_frame_default_init_reg (struct gdbarch
*gdbarch
, int regnum
,
745 struct dwarf2_frame_state_reg
*reg
,
746 struct frame_info
*this_frame
)
748 /* If we have a register that acts as a program counter, mark it as
749 a destination for the return address. If we have a register that
750 serves as the stack pointer, arrange for it to be filled with the
751 call frame address (CFA). The other registers are marked as
754 We copy the return address to the program counter, since many
755 parts in GDB assume that it is possible to get the return address
756 by unwinding the program counter register. However, on ISA's
757 with a dedicated return address register, the CFI usually only
758 contains information to unwind that return address register.
760 The reason we're treating the stack pointer special here is
761 because in many cases GCC doesn't emit CFI for the stack pointer
762 and implicitly assumes that it is equal to the CFA. This makes
763 some sense since the DWARF specification (version 3, draft 8,
766 "Typically, the CFA is defined to be the value of the stack
767 pointer at the call site in the previous frame (which may be
768 different from its value on entry to the current frame)."
770 However, this isn't true for all platforms supported by GCC
771 (e.g. IBM S/390 and zSeries). Those architectures should provide
772 their own architecture-specific initialization function. */
774 if (regnum
== gdbarch_pc_regnum (gdbarch
))
775 reg
->how
= DWARF2_FRAME_REG_RA
;
776 else if (regnum
== gdbarch_sp_regnum (gdbarch
))
777 reg
->how
= DWARF2_FRAME_REG_CFA
;
780 /* Return a default for the architecture-specific operations. */
783 dwarf2_frame_init (struct obstack
*obstack
)
785 struct dwarf2_frame_ops
*ops
;
787 ops
= OBSTACK_ZALLOC (obstack
, struct dwarf2_frame_ops
);
788 ops
->init_reg
= dwarf2_frame_default_init_reg
;
792 /* Set the architecture-specific register state initialization
793 function for GDBARCH to INIT_REG. */
796 dwarf2_frame_set_init_reg (struct gdbarch
*gdbarch
,
797 void (*init_reg
) (struct gdbarch
*, int,
798 struct dwarf2_frame_state_reg
*,
799 struct frame_info
*))
801 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
803 ops
->init_reg
= init_reg
;
806 /* Pre-initialize the register state REG for register REGNUM. */
809 dwarf2_frame_init_reg (struct gdbarch
*gdbarch
, int regnum
,
810 struct dwarf2_frame_state_reg
*reg
,
811 struct frame_info
*this_frame
)
813 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
815 ops
->init_reg (gdbarch
, regnum
, reg
, this_frame
);
818 /* Set the architecture-specific signal trampoline recognition
819 function for GDBARCH to SIGNAL_FRAME_P. */
822 dwarf2_frame_set_signal_frame_p (struct gdbarch
*gdbarch
,
823 int (*signal_frame_p
) (struct gdbarch
*,
824 struct frame_info
*))
826 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
828 ops
->signal_frame_p
= signal_frame_p
;
831 /* Query the architecture-specific signal frame recognizer for
835 dwarf2_frame_signal_frame_p (struct gdbarch
*gdbarch
,
836 struct frame_info
*this_frame
)
838 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
840 if (ops
->signal_frame_p
== NULL
)
842 return ops
->signal_frame_p (gdbarch
, this_frame
);
845 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
849 dwarf2_frame_set_adjust_regnum (struct gdbarch
*gdbarch
,
850 int (*adjust_regnum
) (struct gdbarch
*,
853 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
855 ops
->adjust_regnum
= adjust_regnum
;
858 /* Translate a .eh_frame register to DWARF register, or adjust a .debug_frame
862 dwarf2_frame_adjust_regnum (struct gdbarch
*gdbarch
,
863 int regnum
, int eh_frame_p
)
865 struct dwarf2_frame_ops
*ops
= gdbarch_data (gdbarch
, dwarf2_frame_data
);
867 if (ops
->adjust_regnum
== NULL
)
869 return ops
->adjust_regnum (gdbarch
, regnum
, eh_frame_p
);
873 dwarf2_frame_find_quirks (struct dwarf2_frame_state
*fs
,
874 struct dwarf2_fde
*fde
)
878 s
= find_pc_symtab (fs
->pc
);
882 if (producer_is_realview (s
->producer
))
884 if (fde
->cie
->version
== 1)
885 fs
->armcc_cfa_offsets_sf
= 1;
887 if (fde
->cie
->version
== 1)
888 fs
->armcc_cfa_offsets_reversed
= 1;
890 /* The reversed offset problem is present in some compilers
891 using DWARF3, but it was eventually fixed. Check the ARM
892 defined augmentations, which are in the format "armcc" followed
893 by a list of one-character options. The "+" option means
894 this problem is fixed (no quirk needed). If the armcc
895 augmentation is missing, the quirk is needed. */
896 if (fde
->cie
->version
== 3
897 && (strncmp (fde
->cie
->augmentation
, "armcc", 5) != 0
898 || strchr (fde
->cie
->augmentation
+ 5, '+') == NULL
))
899 fs
->armcc_cfa_offsets_reversed
= 1;
907 dwarf2_compile_cfa_to_ax (struct agent_expr
*expr
, struct axs_value
*loc
,
908 struct gdbarch
*gdbarch
,
910 struct dwarf2_per_cu_data
*data
)
912 const int num_regs
= gdbarch_num_regs (gdbarch
)
913 + gdbarch_num_pseudo_regs (gdbarch
);
914 struct dwarf2_fde
*fde
;
915 CORE_ADDR text_offset
, cfa
;
916 struct dwarf2_frame_state fs
;
919 memset (&fs
, 0, sizeof (struct dwarf2_frame_state
));
923 /* Find the correct FDE. */
924 fde
= dwarf2_frame_find_fde (&fs
.pc
, &text_offset
);
926 error (_("Could not compute CFA; needed to translate this expression"));
928 /* Extract any interesting information from the CIE. */
929 fs
.data_align
= fde
->cie
->data_alignment_factor
;
930 fs
.code_align
= fde
->cie
->code_alignment_factor
;
931 fs
.retaddr_column
= fde
->cie
->return_address_register
;
932 addr_size
= fde
->cie
->addr_size
;
934 /* Check for "quirks" - known bugs in producers. */
935 dwarf2_frame_find_quirks (&fs
, fde
);
937 /* First decode all the insns in the CIE. */
938 execute_cfa_program (fde
, fde
->cie
->initial_instructions
,
939 fde
->cie
->end
, gdbarch
, pc
, &fs
);
941 /* Save the initialized register set. */
942 fs
.initial
= fs
.regs
;
943 fs
.initial
.reg
= dwarf2_frame_state_copy_regs (&fs
.regs
);
945 /* Then decode the insns in the FDE up to our target PC. */
946 execute_cfa_program (fde
, fde
->instructions
, fde
->end
, gdbarch
, pc
, &fs
);
948 /* Calculate the CFA. */
949 switch (fs
.regs
.cfa_how
)
953 int regnum
= gdbarch_dwarf2_reg_to_regnum (gdbarch
, fs
.regs
.cfa_reg
);
956 error (_("Unable to access DWARF register number %d"),
957 (int) fs
.regs
.cfa_reg
); /* FIXME */
958 ax_reg (expr
, regnum
);
960 if (fs
.regs
.cfa_offset
!= 0)
962 if (fs
.armcc_cfa_offsets_reversed
)
963 ax_const_l (expr
, -fs
.regs
.cfa_offset
);
965 ax_const_l (expr
, fs
.regs
.cfa_offset
);
966 ax_simple (expr
, aop_add
);
972 ax_const_l (expr
, text_offset
);
973 dwarf2_compile_expr_to_ax (expr
, loc
, gdbarch
, addr_size
,
975 fs
.regs
.cfa_exp
+ fs
.regs
.cfa_exp_len
,
980 internal_error (__FILE__
, __LINE__
, _("Unknown CFA rule."));
985 struct dwarf2_frame_cache
987 /* DWARF Call Frame Address. */
990 /* Set if the return address column was marked as unavailable
991 (required non-collected memory or registers to compute). */
992 int unavailable_retaddr
;
994 /* Set if the return address column was marked as undefined. */
995 int undefined_retaddr
;
997 /* Saved registers, indexed by GDB register number, not by DWARF
999 struct dwarf2_frame_state_reg
*reg
;
1001 /* Return address register. */
1002 struct dwarf2_frame_state_reg retaddr_reg
;
1004 /* Target address size in bytes. */
1007 /* The .text offset. */
1008 CORE_ADDR text_offset
;
1011 static struct dwarf2_frame_cache
*
1012 dwarf2_frame_cache (struct frame_info
*this_frame
, void **this_cache
)
1014 struct cleanup
*old_chain
;
1015 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
1016 const int num_regs
= gdbarch_num_regs (gdbarch
)
1017 + gdbarch_num_pseudo_regs (gdbarch
);
1018 struct dwarf2_frame_cache
*cache
;
1019 struct dwarf2_frame_state
*fs
;
1020 struct dwarf2_fde
*fde
;
1021 volatile struct gdb_exception ex
;
1026 /* Allocate a new cache. */
1027 cache
= FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache
);
1028 cache
->reg
= FRAME_OBSTACK_CALLOC (num_regs
, struct dwarf2_frame_state_reg
);
1029 *this_cache
= cache
;
1031 /* Allocate and initialize the frame state. */
1032 fs
= XZALLOC (struct dwarf2_frame_state
);
1033 old_chain
= make_cleanup (dwarf2_frame_state_free
, fs
);
1037 Note that if the next frame is never supposed to return (i.e. a call
1038 to abort), the compiler might optimize away the instruction at
1039 its return address. As a result the return address will
1040 point at some random instruction, and the CFI for that
1041 instruction is probably worthless to us. GCC's unwinder solves
1042 this problem by substracting 1 from the return address to get an
1043 address in the middle of a presumed call instruction (or the
1044 instruction in the associated delay slot). This should only be
1045 done for "normal" frames and not for resume-type frames (signal
1046 handlers, sentinel frames, dummy frames). The function
1047 get_frame_address_in_block does just this. It's not clear how
1048 reliable the method is though; there is the potential for the
1049 register state pre-call being different to that on return. */
1050 fs
->pc
= get_frame_address_in_block (this_frame
);
1052 /* Find the correct FDE. */
1053 fde
= dwarf2_frame_find_fde (&fs
->pc
, &cache
->text_offset
);
1054 gdb_assert (fde
!= NULL
);
1056 /* Extract any interesting information from the CIE. */
1057 fs
->data_align
= fde
->cie
->data_alignment_factor
;
1058 fs
->code_align
= fde
->cie
->code_alignment_factor
;
1059 fs
->retaddr_column
= fde
->cie
->return_address_register
;
1060 cache
->addr_size
= fde
->cie
->addr_size
;
1062 /* Check for "quirks" - known bugs in producers. */
1063 dwarf2_frame_find_quirks (fs
, fde
);
1065 /* First decode all the insns in the CIE. */
1066 execute_cfa_program (fde
, fde
->cie
->initial_instructions
,
1067 fde
->cie
->end
, gdbarch
, get_frame_pc (this_frame
), fs
);
1069 /* Save the initialized register set. */
1070 fs
->initial
= fs
->regs
;
1071 fs
->initial
.reg
= dwarf2_frame_state_copy_regs (&fs
->regs
);
1073 /* Then decode the insns in the FDE up to our target PC. */
1074 execute_cfa_program (fde
, fde
->instructions
, fde
->end
, gdbarch
,
1075 get_frame_pc (this_frame
), fs
);
1077 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1079 /* Calculate the CFA. */
1080 switch (fs
->regs
.cfa_how
)
1082 case CFA_REG_OFFSET
:
1083 cache
->cfa
= read_reg (this_frame
, fs
->regs
.cfa_reg
);
1084 if (fs
->armcc_cfa_offsets_reversed
)
1085 cache
->cfa
-= fs
->regs
.cfa_offset
;
1087 cache
->cfa
+= fs
->regs
.cfa_offset
;
1092 execute_stack_op (fs
->regs
.cfa_exp
, fs
->regs
.cfa_exp_len
,
1093 cache
->addr_size
, cache
->text_offset
,
1098 internal_error (__FILE__
, __LINE__
, _("Unknown CFA rule."));
1103 if (ex
.error
== NOT_AVAILABLE_ERROR
)
1105 cache
->unavailable_retaddr
= 1;
1109 throw_exception (ex
);
1112 /* Initialize the register state. */
1116 for (regnum
= 0; regnum
< num_regs
; regnum
++)
1117 dwarf2_frame_init_reg (gdbarch
, regnum
, &cache
->reg
[regnum
], this_frame
);
1120 /* Go through the DWARF2 CFI generated table and save its register
1121 location information in the cache. Note that we don't skip the
1122 return address column; it's perfectly all right for it to
1123 correspond to a real register. If it doesn't correspond to a
1124 real register, or if we shouldn't treat it as such,
1125 gdbarch_dwarf2_reg_to_regnum should be defined to return a number outside
1126 the range [0, gdbarch_num_regs). */
1128 int column
; /* CFI speak for "register number". */
1130 for (column
= 0; column
< fs
->regs
.num_regs
; column
++)
1132 /* Use the GDB register number as the destination index. */
1133 int regnum
= gdbarch_dwarf2_reg_to_regnum (gdbarch
, column
);
1135 /* If there's no corresponding GDB register, ignore it. */
1136 if (regnum
< 0 || regnum
>= num_regs
)
1139 /* NOTE: cagney/2003-09-05: CFI should specify the disposition
1140 of all debug info registers. If it doesn't, complain (but
1141 not too loudly). It turns out that GCC assumes that an
1142 unspecified register implies "same value" when CFI (draft
1143 7) specifies nothing at all. Such a register could equally
1144 be interpreted as "undefined". Also note that this check
1145 isn't sufficient; it only checks that all registers in the
1146 range [0 .. max column] are specified, and won't detect
1147 problems when a debug info register falls outside of the
1148 table. We need a way of iterating through all the valid
1149 DWARF2 register numbers. */
1150 if (fs
->regs
.reg
[column
].how
== DWARF2_FRAME_REG_UNSPECIFIED
)
1152 if (cache
->reg
[regnum
].how
== DWARF2_FRAME_REG_UNSPECIFIED
)
1153 complaint (&symfile_complaints
, _("\
1154 incomplete CFI data; unspecified registers (e.g., %s) at %s"),
1155 gdbarch_register_name (gdbarch
, regnum
),
1156 paddress (gdbarch
, fs
->pc
));
1159 cache
->reg
[regnum
] = fs
->regs
.reg
[column
];
1163 /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information
1164 we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */
1168 for (regnum
= 0; regnum
< num_regs
; regnum
++)
1170 if (cache
->reg
[regnum
].how
== DWARF2_FRAME_REG_RA
1171 || cache
->reg
[regnum
].how
== DWARF2_FRAME_REG_RA_OFFSET
)
1173 struct dwarf2_frame_state_reg
*retaddr_reg
=
1174 &fs
->regs
.reg
[fs
->retaddr_column
];
1176 /* It seems rather bizarre to specify an "empty" column as
1177 the return adress column. However, this is exactly
1178 what GCC does on some targets. It turns out that GCC
1179 assumes that the return address can be found in the
1180 register corresponding to the return address column.
1181 Incidentally, that's how we should treat a return
1182 address column specifying "same value" too. */
1183 if (fs
->retaddr_column
< fs
->regs
.num_regs
1184 && retaddr_reg
->how
!= DWARF2_FRAME_REG_UNSPECIFIED
1185 && retaddr_reg
->how
!= DWARF2_FRAME_REG_SAME_VALUE
)
1187 if (cache
->reg
[regnum
].how
== DWARF2_FRAME_REG_RA
)
1188 cache
->reg
[regnum
] = *retaddr_reg
;
1190 cache
->retaddr_reg
= *retaddr_reg
;
1194 if (cache
->reg
[regnum
].how
== DWARF2_FRAME_REG_RA
)
1196 cache
->reg
[regnum
].loc
.reg
= fs
->retaddr_column
;
1197 cache
->reg
[regnum
].how
= DWARF2_FRAME_REG_SAVED_REG
;
1201 cache
->retaddr_reg
.loc
.reg
= fs
->retaddr_column
;
1202 cache
->retaddr_reg
.how
= DWARF2_FRAME_REG_SAVED_REG
;
1209 if (fs
->retaddr_column
< fs
->regs
.num_regs
1210 && fs
->regs
.reg
[fs
->retaddr_column
].how
== DWARF2_FRAME_REG_UNDEFINED
)
1211 cache
->undefined_retaddr
= 1;
1213 do_cleanups (old_chain
);
1218 static enum unwind_stop_reason
1219 dwarf2_frame_unwind_stop_reason (struct frame_info
*this_frame
,
1222 struct dwarf2_frame_cache
*cache
1223 = dwarf2_frame_cache (this_frame
, this_cache
);
1225 if (cache
->unavailable_retaddr
)
1226 return UNWIND_UNAVAILABLE
;
1228 if (cache
->undefined_retaddr
)
1229 return UNWIND_OUTERMOST
;
1231 return UNWIND_NO_REASON
;
1235 dwarf2_frame_this_id (struct frame_info
*this_frame
, void **this_cache
,
1236 struct frame_id
*this_id
)
1238 struct dwarf2_frame_cache
*cache
=
1239 dwarf2_frame_cache (this_frame
, this_cache
);
1241 if (cache
->unavailable_retaddr
)
1244 if (cache
->undefined_retaddr
)
1247 (*this_id
) = frame_id_build (cache
->cfa
, get_frame_func (this_frame
));
1250 static struct value
*
1251 dwarf2_frame_prev_register (struct frame_info
*this_frame
, void **this_cache
,
1254 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
1255 struct dwarf2_frame_cache
*cache
=
1256 dwarf2_frame_cache (this_frame
, this_cache
);
1260 switch (cache
->reg
[regnum
].how
)
1262 case DWARF2_FRAME_REG_UNDEFINED
:
1263 /* If CFI explicitly specified that the value isn't defined,
1264 mark it as optimized away; the value isn't available. */
1265 return frame_unwind_got_optimized (this_frame
, regnum
);
1267 case DWARF2_FRAME_REG_SAVED_OFFSET
:
1268 addr
= cache
->cfa
+ cache
->reg
[regnum
].loc
.offset
;
1269 return frame_unwind_got_memory (this_frame
, regnum
, addr
);
1271 case DWARF2_FRAME_REG_SAVED_REG
:
1273 = gdbarch_dwarf2_reg_to_regnum (gdbarch
, cache
->reg
[regnum
].loc
.reg
);
1274 return frame_unwind_got_register (this_frame
, regnum
, realnum
);
1276 case DWARF2_FRAME_REG_SAVED_EXP
:
1277 addr
= execute_stack_op (cache
->reg
[regnum
].loc
.exp
,
1278 cache
->reg
[regnum
].exp_len
,
1279 cache
->addr_size
, cache
->text_offset
,
1280 this_frame
, cache
->cfa
, 1);
1281 return frame_unwind_got_memory (this_frame
, regnum
, addr
);
1283 case DWARF2_FRAME_REG_SAVED_VAL_OFFSET
:
1284 addr
= cache
->cfa
+ cache
->reg
[regnum
].loc
.offset
;
1285 return frame_unwind_got_constant (this_frame
, regnum
, addr
);
1287 case DWARF2_FRAME_REG_SAVED_VAL_EXP
:
1288 addr
= execute_stack_op (cache
->reg
[regnum
].loc
.exp
,
1289 cache
->reg
[regnum
].exp_len
,
1290 cache
->addr_size
, cache
->text_offset
,
1291 this_frame
, cache
->cfa
, 1);
1292 return frame_unwind_got_constant (this_frame
, regnum
, addr
);
1294 case DWARF2_FRAME_REG_UNSPECIFIED
:
1295 /* GCC, in its infinite wisdom decided to not provide unwind
1296 information for registers that are "same value". Since
1297 DWARF2 (3 draft 7) doesn't define such behavior, said
1298 registers are actually undefined (which is different to CFI
1299 "undefined"). Code above issues a complaint about this.
1300 Here just fudge the books, assume GCC, and that the value is
1301 more inner on the stack. */
1302 return frame_unwind_got_register (this_frame
, regnum
, regnum
);
1304 case DWARF2_FRAME_REG_SAME_VALUE
:
1305 return frame_unwind_got_register (this_frame
, regnum
, regnum
);
1307 case DWARF2_FRAME_REG_CFA
:
1308 return frame_unwind_got_address (this_frame
, regnum
, cache
->cfa
);
1310 case DWARF2_FRAME_REG_CFA_OFFSET
:
1311 addr
= cache
->cfa
+ cache
->reg
[regnum
].loc
.offset
;
1312 return frame_unwind_got_address (this_frame
, regnum
, addr
);
1314 case DWARF2_FRAME_REG_RA_OFFSET
:
1315 addr
= cache
->reg
[regnum
].loc
.offset
;
1316 regnum
= gdbarch_dwarf2_reg_to_regnum
1317 (gdbarch
, cache
->retaddr_reg
.loc
.reg
);
1318 addr
+= get_frame_register_unsigned (this_frame
, regnum
);
1319 return frame_unwind_got_address (this_frame
, regnum
, addr
);
1321 case DWARF2_FRAME_REG_FN
:
1322 return cache
->reg
[regnum
].loc
.fn (this_frame
, this_cache
, regnum
);
1325 internal_error (__FILE__
, __LINE__
, _("Unknown register rule."));
1330 dwarf2_frame_sniffer (const struct frame_unwind
*self
,
1331 struct frame_info
*this_frame
, void **this_cache
)
1333 /* Grab an address that is guarenteed to reside somewhere within the
1334 function. get_frame_pc(), with a no-return next function, can
1335 end up returning something past the end of this function's body.
1336 If the frame we're sniffing for is a signal frame whose start
1337 address is placed on the stack by the OS, its FDE must
1338 extend one byte before its start address or we could potentially
1339 select the FDE of the previous function. */
1340 CORE_ADDR block_addr
= get_frame_address_in_block (this_frame
);
1341 struct dwarf2_fde
*fde
= dwarf2_frame_find_fde (&block_addr
, NULL
);
1346 /* On some targets, signal trampolines may have unwind information.
1347 We need to recognize them so that we set the frame type
1350 if (fde
->cie
->signal_frame
1351 || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame
),
1353 return self
->type
== SIGTRAMP_FRAME
;
1355 return self
->type
!= SIGTRAMP_FRAME
;
1358 static const struct frame_unwind dwarf2_frame_unwind
=
1361 dwarf2_frame_unwind_stop_reason
,
1362 dwarf2_frame_this_id
,
1363 dwarf2_frame_prev_register
,
1365 dwarf2_frame_sniffer
1368 static const struct frame_unwind dwarf2_signal_frame_unwind
=
1371 dwarf2_frame_unwind_stop_reason
,
1372 dwarf2_frame_this_id
,
1373 dwarf2_frame_prev_register
,
1375 dwarf2_frame_sniffer
1378 /* Append the DWARF-2 frame unwinders to GDBARCH's list. */
1381 dwarf2_append_unwinders (struct gdbarch
*gdbarch
)
1383 frame_unwind_append_unwinder (gdbarch
, &dwarf2_frame_unwind
);
1384 frame_unwind_append_unwinder (gdbarch
, &dwarf2_signal_frame_unwind
);
1388 /* There is no explicitly defined relationship between the CFA and the
1389 location of frame's local variables and arguments/parameters.
1390 Therefore, frame base methods on this page should probably only be
1391 used as a last resort, just to avoid printing total garbage as a
1392 response to the "info frame" command. */
1395 dwarf2_frame_base_address (struct frame_info
*this_frame
, void **this_cache
)
1397 struct dwarf2_frame_cache
*cache
=
1398 dwarf2_frame_cache (this_frame
, this_cache
);
1403 static const struct frame_base dwarf2_frame_base
=
1405 &dwarf2_frame_unwind
,
1406 dwarf2_frame_base_address
,
1407 dwarf2_frame_base_address
,
1408 dwarf2_frame_base_address
1411 const struct frame_base
*
1412 dwarf2_frame_base_sniffer (struct frame_info
*this_frame
)
1414 CORE_ADDR block_addr
= get_frame_address_in_block (this_frame
);
1416 if (dwarf2_frame_find_fde (&block_addr
, NULL
))
1417 return &dwarf2_frame_base
;
1422 /* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from
1423 the DWARF unwinder. This is used to implement
1424 DW_OP_call_frame_cfa. */
1427 dwarf2_frame_cfa (struct frame_info
*this_frame
)
1429 while (get_frame_type (this_frame
) == INLINE_FRAME
)
1430 this_frame
= get_prev_frame (this_frame
);
1431 /* This restriction could be lifted if other unwinders are known to
1432 compute the frame base in a way compatible with the DWARF
1434 if (! frame_unwinder_is (this_frame
, &dwarf2_frame_unwind
))
1435 error (_("can't compute CFA for this frame"));
1436 return get_frame_base (this_frame
);
1439 const struct objfile_data
*dwarf2_frame_objfile_data
;
1442 read_1_byte (bfd
*abfd
, gdb_byte
*buf
)
1444 return bfd_get_8 (abfd
, buf
);
1448 read_4_bytes (bfd
*abfd
, gdb_byte
*buf
)
1450 return bfd_get_32 (abfd
, buf
);
1454 read_8_bytes (bfd
*abfd
, gdb_byte
*buf
)
1456 return bfd_get_64 (abfd
, buf
);
1460 read_unsigned_leb128 (bfd
*abfd
, gdb_byte
*buf
, unsigned int *bytes_read_ptr
)
1463 unsigned int num_read
;
1473 byte
= bfd_get_8 (abfd
, (bfd_byte
*) buf
);
1476 result
|= ((byte
& 0x7f) << shift
);
1479 while (byte
& 0x80);
1481 *bytes_read_ptr
= num_read
;
1487 read_signed_leb128 (bfd
*abfd
, gdb_byte
*buf
, unsigned int *bytes_read_ptr
)
1491 unsigned int num_read
;
1500 byte
= bfd_get_8 (abfd
, (bfd_byte
*) buf
);
1503 result
|= ((byte
& 0x7f) << shift
);
1506 while (byte
& 0x80);
1508 if (shift
< 8 * sizeof (result
) && (byte
& 0x40))
1509 result
|= -(((LONGEST
)1) << shift
);
1511 *bytes_read_ptr
= num_read
;
1517 read_initial_length (bfd
*abfd
, gdb_byte
*buf
, unsigned int *bytes_read_ptr
)
1521 result
= bfd_get_32 (abfd
, buf
);
1522 if (result
== 0xffffffff)
1524 result
= bfd_get_64 (abfd
, buf
+ 4);
1525 *bytes_read_ptr
= 12;
1528 *bytes_read_ptr
= 4;
1534 /* Pointer encoding helper functions. */
1536 /* GCC supports exception handling based on DWARF2 CFI. However, for
1537 technical reasons, it encodes addresses in its FDE's in a different
1538 way. Several "pointer encodings" are supported. The encoding
1539 that's used for a particular FDE is determined by the 'R'
1540 augmentation in the associated CIE. The argument of this
1541 augmentation is a single byte.
1543 The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a
1544 LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether
1545 the address is signed or unsigned. Bits 4, 5 and 6 encode how the
1546 address should be interpreted (absolute, relative to the current
1547 position in the FDE, ...). Bit 7, indicates that the address
1548 should be dereferenced. */
1551 encoding_for_size (unsigned int size
)
1556 return DW_EH_PE_udata2
;
1558 return DW_EH_PE_udata4
;
1560 return DW_EH_PE_udata8
;
1562 internal_error (__FILE__
, __LINE__
, _("Unsupported address size"));
1567 read_encoded_value (struct comp_unit
*unit
, gdb_byte encoding
,
1568 int ptr_len
, const gdb_byte
*buf
,
1569 unsigned int *bytes_read_ptr
,
1570 CORE_ADDR func_base
)
1575 /* GCC currently doesn't generate DW_EH_PE_indirect encodings for
1577 if (encoding
& DW_EH_PE_indirect
)
1578 internal_error (__FILE__
, __LINE__
,
1579 _("Unsupported encoding: DW_EH_PE_indirect"));
1581 *bytes_read_ptr
= 0;
1583 switch (encoding
& 0x70)
1585 case DW_EH_PE_absptr
:
1588 case DW_EH_PE_pcrel
:
1589 base
= bfd_get_section_vma (unit
->abfd
, unit
->dwarf_frame_section
);
1590 base
+= (buf
- unit
->dwarf_frame_buffer
);
1592 case DW_EH_PE_datarel
:
1595 case DW_EH_PE_textrel
:
1598 case DW_EH_PE_funcrel
:
1601 case DW_EH_PE_aligned
:
1603 offset
= buf
- unit
->dwarf_frame_buffer
;
1604 if ((offset
% ptr_len
) != 0)
1606 *bytes_read_ptr
= ptr_len
- (offset
% ptr_len
);
1607 buf
+= *bytes_read_ptr
;
1611 internal_error (__FILE__
, __LINE__
,
1612 _("Invalid or unsupported encoding"));
1615 if ((encoding
& 0x07) == 0x00)
1617 encoding
|= encoding_for_size (ptr_len
);
1618 if (bfd_get_sign_extend_vma (unit
->abfd
))
1619 encoding
|= DW_EH_PE_signed
;
1622 switch (encoding
& 0x0f)
1624 case DW_EH_PE_uleb128
:
1627 const gdb_byte
*end_buf
= buf
+ (sizeof (value
) + 1) * 8 / 7;
1629 *bytes_read_ptr
+= read_uleb128 (buf
, end_buf
, &value
) - buf
;
1630 return base
+ value
;
1632 case DW_EH_PE_udata2
:
1633 *bytes_read_ptr
+= 2;
1634 return (base
+ bfd_get_16 (unit
->abfd
, (bfd_byte
*) buf
));
1635 case DW_EH_PE_udata4
:
1636 *bytes_read_ptr
+= 4;
1637 return (base
+ bfd_get_32 (unit
->abfd
, (bfd_byte
*) buf
));
1638 case DW_EH_PE_udata8
:
1639 *bytes_read_ptr
+= 8;
1640 return (base
+ bfd_get_64 (unit
->abfd
, (bfd_byte
*) buf
));
1641 case DW_EH_PE_sleb128
:
1644 const gdb_byte
*end_buf
= buf
+ (sizeof (value
) + 1) * 8 / 7;
1646 *bytes_read_ptr
+= read_sleb128 (buf
, end_buf
, &value
) - buf
;
1647 return base
+ value
;
1649 case DW_EH_PE_sdata2
:
1650 *bytes_read_ptr
+= 2;
1651 return (base
+ bfd_get_signed_16 (unit
->abfd
, (bfd_byte
*) buf
));
1652 case DW_EH_PE_sdata4
:
1653 *bytes_read_ptr
+= 4;
1654 return (base
+ bfd_get_signed_32 (unit
->abfd
, (bfd_byte
*) buf
));
1655 case DW_EH_PE_sdata8
:
1656 *bytes_read_ptr
+= 8;
1657 return (base
+ bfd_get_signed_64 (unit
->abfd
, (bfd_byte
*) buf
));
1659 internal_error (__FILE__
, __LINE__
,
1660 _("Invalid or unsupported encoding"));
1666 bsearch_cie_cmp (const void *key
, const void *element
)
1668 ULONGEST cie_pointer
= *(ULONGEST
*) key
;
1669 struct dwarf2_cie
*cie
= *(struct dwarf2_cie
**) element
;
1671 if (cie_pointer
== cie
->cie_pointer
)
1674 return (cie_pointer
< cie
->cie_pointer
) ? -1 : 1;
1677 /* Find CIE with the given CIE_POINTER in CIE_TABLE. */
1678 static struct dwarf2_cie
*
1679 find_cie (struct dwarf2_cie_table
*cie_table
, ULONGEST cie_pointer
)
1681 struct dwarf2_cie
**p_cie
;
1683 /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to
1684 bsearch be non-NULL. */
1685 if (cie_table
->entries
== NULL
)
1687 gdb_assert (cie_table
->num_entries
== 0);
1691 p_cie
= bsearch (&cie_pointer
, cie_table
->entries
, cie_table
->num_entries
,
1692 sizeof (cie_table
->entries
[0]), bsearch_cie_cmp
);
1698 /* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */
1700 add_cie (struct dwarf2_cie_table
*cie_table
, struct dwarf2_cie
*cie
)
1702 const int n
= cie_table
->num_entries
;
1705 || cie_table
->entries
[n
- 1]->cie_pointer
< cie
->cie_pointer
);
1707 cie_table
->entries
=
1708 xrealloc (cie_table
->entries
, (n
+ 1) * sizeof (cie_table
->entries
[0]));
1709 cie_table
->entries
[n
] = cie
;
1710 cie_table
->num_entries
= n
+ 1;
1714 bsearch_fde_cmp (const void *key
, const void *element
)
1716 CORE_ADDR seek_pc
= *(CORE_ADDR
*) key
;
1717 struct dwarf2_fde
*fde
= *(struct dwarf2_fde
**) element
;
1719 if (seek_pc
< fde
->initial_location
)
1721 if (seek_pc
< fde
->initial_location
+ fde
->address_range
)
1726 /* Find the FDE for *PC. Return a pointer to the FDE, and store the
1727 inital location associated with it into *PC. */
1729 static struct dwarf2_fde
*
1730 dwarf2_frame_find_fde (CORE_ADDR
*pc
, CORE_ADDR
*out_offset
)
1732 struct objfile
*objfile
;
1734 ALL_OBJFILES (objfile
)
1736 struct dwarf2_fde_table
*fde_table
;
1737 struct dwarf2_fde
**p_fde
;
1741 fde_table
= objfile_data (objfile
, dwarf2_frame_objfile_data
);
1742 if (fde_table
== NULL
)
1744 dwarf2_build_frame_info (objfile
);
1745 fde_table
= objfile_data (objfile
, dwarf2_frame_objfile_data
);
1747 gdb_assert (fde_table
!= NULL
);
1749 if (fde_table
->num_entries
== 0)
1752 gdb_assert (objfile
->section_offsets
);
1753 offset
= ANOFFSET (objfile
->section_offsets
, SECT_OFF_TEXT (objfile
));
1755 gdb_assert (fde_table
->num_entries
> 0);
1756 if (*pc
< offset
+ fde_table
->entries
[0]->initial_location
)
1759 seek_pc
= *pc
- offset
;
1760 p_fde
= bsearch (&seek_pc
, fde_table
->entries
, fde_table
->num_entries
,
1761 sizeof (fde_table
->entries
[0]), bsearch_fde_cmp
);
1764 *pc
= (*p_fde
)->initial_location
+ offset
;
1766 *out_offset
= offset
;
1773 /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */
1775 add_fde (struct dwarf2_fde_table
*fde_table
, struct dwarf2_fde
*fde
)
1777 if (fde
->address_range
== 0)
1778 /* Discard useless FDEs. */
1781 fde_table
->num_entries
+= 1;
1782 fde_table
->entries
=
1783 xrealloc (fde_table
->entries
,
1784 fde_table
->num_entries
* sizeof (fde_table
->entries
[0]));
1785 fde_table
->entries
[fde_table
->num_entries
- 1] = fde
;
1788 #ifdef CC_HAS_LONG_LONG
1789 #define DW64_CIE_ID 0xffffffffffffffffULL
1791 #define DW64_CIE_ID ~0
1794 static gdb_byte
*decode_frame_entry (struct comp_unit
*unit
, gdb_byte
*start
,
1796 struct dwarf2_cie_table
*cie_table
,
1797 struct dwarf2_fde_table
*fde_table
);
1799 /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise
1800 the next byte to be processed. */
1802 decode_frame_entry_1 (struct comp_unit
*unit
, gdb_byte
*start
, int eh_frame_p
,
1803 struct dwarf2_cie_table
*cie_table
,
1804 struct dwarf2_fde_table
*fde_table
)
1806 struct gdbarch
*gdbarch
= get_objfile_arch (unit
->objfile
);
1807 gdb_byte
*buf
, *end
;
1809 unsigned int bytes_read
;
1812 ULONGEST cie_pointer
;
1815 length
= read_initial_length (unit
->abfd
, buf
, &bytes_read
);
1819 /* Are we still within the section? */
1820 if (end
> unit
->dwarf_frame_buffer
+ unit
->dwarf_frame_size
)
1826 /* Distinguish between 32 and 64-bit encoded frame info. */
1827 dwarf64_p
= (bytes_read
== 12);
1829 /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */
1833 cie_id
= DW64_CIE_ID
;
1839 cie_pointer
= read_8_bytes (unit
->abfd
, buf
);
1844 cie_pointer
= read_4_bytes (unit
->abfd
, buf
);
1848 if (cie_pointer
== cie_id
)
1850 /* This is a CIE. */
1851 struct dwarf2_cie
*cie
;
1853 unsigned int cie_version
;
1855 /* Record the offset into the .debug_frame section of this CIE. */
1856 cie_pointer
= start
- unit
->dwarf_frame_buffer
;
1858 /* Check whether we've already read it. */
1859 if (find_cie (cie_table
, cie_pointer
))
1862 cie
= (struct dwarf2_cie
*)
1863 obstack_alloc (&unit
->objfile
->objfile_obstack
,
1864 sizeof (struct dwarf2_cie
));
1865 cie
->initial_instructions
= NULL
;
1866 cie
->cie_pointer
= cie_pointer
;
1868 /* The encoding for FDE's in a normal .debug_frame section
1869 depends on the target address size. */
1870 cie
->encoding
= DW_EH_PE_absptr
;
1872 /* We'll determine the final value later, but we need to
1873 initialize it conservatively. */
1874 cie
->signal_frame
= 0;
1876 /* Check version number. */
1877 cie_version
= read_1_byte (unit
->abfd
, buf
);
1878 if (cie_version
!= 1 && cie_version
!= 3 && cie_version
!= 4)
1880 cie
->version
= cie_version
;
1883 /* Interpret the interesting bits of the augmentation. */
1884 cie
->augmentation
= augmentation
= (char *) buf
;
1885 buf
+= (strlen (augmentation
) + 1);
1887 /* Ignore armcc augmentations. We only use them for quirks,
1888 and that doesn't happen until later. */
1889 if (strncmp (augmentation
, "armcc", 5) == 0)
1890 augmentation
+= strlen (augmentation
);
1892 /* The GCC 2.x "eh" augmentation has a pointer immediately
1893 following the augmentation string, so it must be handled
1895 if (augmentation
[0] == 'e' && augmentation
[1] == 'h')
1898 buf
+= gdbarch_ptr_bit (gdbarch
) / TARGET_CHAR_BIT
;
1902 if (cie
->version
>= 4)
1904 /* FIXME: check that this is the same as from the CU header. */
1905 cie
->addr_size
= read_1_byte (unit
->abfd
, buf
);
1907 cie
->segment_size
= read_1_byte (unit
->abfd
, buf
);
1912 cie
->addr_size
= gdbarch_dwarf2_addr_size (gdbarch
);
1913 cie
->segment_size
= 0;
1915 /* Address values in .eh_frame sections are defined to have the
1916 target's pointer size. Watchout: This breaks frame info for
1917 targets with pointer size < address size, unless a .debug_frame
1918 section exists as well. */
1920 cie
->ptr_size
= gdbarch_ptr_bit (gdbarch
) / TARGET_CHAR_BIT
;
1922 cie
->ptr_size
= cie
->addr_size
;
1924 cie
->code_alignment_factor
=
1925 read_unsigned_leb128 (unit
->abfd
, buf
, &bytes_read
);
1928 cie
->data_alignment_factor
=
1929 read_signed_leb128 (unit
->abfd
, buf
, &bytes_read
);
1932 if (cie_version
== 1)
1934 cie
->return_address_register
= read_1_byte (unit
->abfd
, buf
);
1938 cie
->return_address_register
= read_unsigned_leb128 (unit
->abfd
, buf
,
1940 cie
->return_address_register
1941 = dwarf2_frame_adjust_regnum (gdbarch
,
1942 cie
->return_address_register
,
1947 cie
->saw_z_augmentation
= (*augmentation
== 'z');
1948 if (cie
->saw_z_augmentation
)
1952 length
= read_unsigned_leb128 (unit
->abfd
, buf
, &bytes_read
);
1956 cie
->initial_instructions
= buf
+ length
;
1960 while (*augmentation
)
1962 /* "L" indicates a byte showing how the LSDA pointer is encoded. */
1963 if (*augmentation
== 'L')
1970 /* "R" indicates a byte indicating how FDE addresses are encoded. */
1971 else if (*augmentation
== 'R')
1973 cie
->encoding
= *buf
++;
1977 /* "P" indicates a personality routine in the CIE augmentation. */
1978 else if (*augmentation
== 'P')
1980 /* Skip. Avoid indirection since we throw away the result. */
1981 gdb_byte encoding
= (*buf
++) & ~DW_EH_PE_indirect
;
1982 read_encoded_value (unit
, encoding
, cie
->ptr_size
,
1983 buf
, &bytes_read
, 0);
1988 /* "S" indicates a signal frame, such that the return
1989 address must not be decremented to locate the call frame
1990 info for the previous frame; it might even be the first
1991 instruction of a function, so decrementing it would take
1992 us to a different function. */
1993 else if (*augmentation
== 'S')
1995 cie
->signal_frame
= 1;
1999 /* Otherwise we have an unknown augmentation. Assume that either
2000 there is no augmentation data, or we saw a 'z' prefix. */
2003 if (cie
->initial_instructions
)
2004 buf
= cie
->initial_instructions
;
2009 cie
->initial_instructions
= buf
;
2013 add_cie (cie_table
, cie
);
2017 /* This is a FDE. */
2018 struct dwarf2_fde
*fde
;
2020 /* In an .eh_frame section, the CIE pointer is the delta between the
2021 address within the FDE where the CIE pointer is stored and the
2022 address of the CIE. Convert it to an offset into the .eh_frame
2026 cie_pointer
= buf
- unit
->dwarf_frame_buffer
- cie_pointer
;
2027 cie_pointer
-= (dwarf64_p
? 8 : 4);
2030 /* In either case, validate the result is still within the section. */
2031 if (cie_pointer
>= unit
->dwarf_frame_size
)
2034 fde
= (struct dwarf2_fde
*)
2035 obstack_alloc (&unit
->objfile
->objfile_obstack
,
2036 sizeof (struct dwarf2_fde
));
2037 fde
->cie
= find_cie (cie_table
, cie_pointer
);
2038 if (fde
->cie
== NULL
)
2040 decode_frame_entry (unit
, unit
->dwarf_frame_buffer
+ cie_pointer
,
2041 eh_frame_p
, cie_table
, fde_table
);
2042 fde
->cie
= find_cie (cie_table
, cie_pointer
);
2045 gdb_assert (fde
->cie
!= NULL
);
2047 fde
->initial_location
=
2048 read_encoded_value (unit
, fde
->cie
->encoding
, fde
->cie
->ptr_size
,
2049 buf
, &bytes_read
, 0);
2052 fde
->address_range
=
2053 read_encoded_value (unit
, fde
->cie
->encoding
& 0x0f,
2054 fde
->cie
->ptr_size
, buf
, &bytes_read
, 0);
2057 /* A 'z' augmentation in the CIE implies the presence of an
2058 augmentation field in the FDE as well. The only thing known
2059 to be in here at present is the LSDA entry for EH. So we
2060 can skip the whole thing. */
2061 if (fde
->cie
->saw_z_augmentation
)
2065 length
= read_unsigned_leb128 (unit
->abfd
, buf
, &bytes_read
);
2066 buf
+= bytes_read
+ length
;
2071 fde
->instructions
= buf
;
2074 fde
->eh_frame_p
= eh_frame_p
;
2076 add_fde (fde_table
, fde
);
2082 /* Read a CIE or FDE in BUF and decode it. */
2084 decode_frame_entry (struct comp_unit
*unit
, gdb_byte
*start
, int eh_frame_p
,
2085 struct dwarf2_cie_table
*cie_table
,
2086 struct dwarf2_fde_table
*fde_table
)
2088 enum { NONE
, ALIGN4
, ALIGN8
, FAIL
} workaround
= NONE
;
2090 ptrdiff_t start_offset
;
2094 ret
= decode_frame_entry_1 (unit
, start
, eh_frame_p
,
2095 cie_table
, fde_table
);
2099 /* We have corrupt input data of some form. */
2101 /* ??? Try, weakly, to work around compiler/assembler/linker bugs
2102 and mismatches wrt padding and alignment of debug sections. */
2103 /* Note that there is no requirement in the standard for any
2104 alignment at all in the frame unwind sections. Testing for
2105 alignment before trying to interpret data would be incorrect.
2107 However, GCC traditionally arranged for frame sections to be
2108 sized such that the FDE length and CIE fields happen to be
2109 aligned (in theory, for performance). This, unfortunately,
2110 was done with .align directives, which had the side effect of
2111 forcing the section to be aligned by the linker.
2113 This becomes a problem when you have some other producer that
2114 creates frame sections that are not as strictly aligned. That
2115 produces a hole in the frame info that gets filled by the
2118 The GCC behaviour is arguably a bug, but it's effectively now
2119 part of the ABI, so we're now stuck with it, at least at the
2120 object file level. A smart linker may decide, in the process
2121 of compressing duplicate CIE information, that it can rewrite
2122 the entire output section without this extra padding. */
2124 start_offset
= start
- unit
->dwarf_frame_buffer
;
2125 if (workaround
< ALIGN4
&& (start_offset
& 3) != 0)
2127 start
+= 4 - (start_offset
& 3);
2128 workaround
= ALIGN4
;
2131 if (workaround
< ALIGN8
&& (start_offset
& 7) != 0)
2133 start
+= 8 - (start_offset
& 7);
2134 workaround
= ALIGN8
;
2138 /* Nothing left to try. Arrange to return as if we've consumed
2139 the entire input section. Hopefully we'll get valid info from
2140 the other of .debug_frame/.eh_frame. */
2142 ret
= unit
->dwarf_frame_buffer
+ unit
->dwarf_frame_size
;
2152 complaint (&symfile_complaints
, _("\
2153 Corrupt data in %s:%s; align 4 workaround apparently succeeded"),
2154 unit
->dwarf_frame_section
->owner
->filename
,
2155 unit
->dwarf_frame_section
->name
);
2159 complaint (&symfile_complaints
, _("\
2160 Corrupt data in %s:%s; align 8 workaround apparently succeeded"),
2161 unit
->dwarf_frame_section
->owner
->filename
,
2162 unit
->dwarf_frame_section
->name
);
2166 complaint (&symfile_complaints
,
2167 _("Corrupt data in %s:%s"),
2168 unit
->dwarf_frame_section
->owner
->filename
,
2169 unit
->dwarf_frame_section
->name
);
2177 /* Imported from dwarf2read.c. */
2178 extern void dwarf2_get_section_info (struct objfile
*, const char *,
2179 asection
**, gdb_byte
**,
2183 qsort_fde_cmp (const void *a
, const void *b
)
2185 struct dwarf2_fde
*aa
= *(struct dwarf2_fde
**)a
;
2186 struct dwarf2_fde
*bb
= *(struct dwarf2_fde
**)b
;
2188 if (aa
->initial_location
== bb
->initial_location
)
2190 if (aa
->address_range
!= bb
->address_range
2191 && aa
->eh_frame_p
== 0 && bb
->eh_frame_p
== 0)
2192 /* Linker bug, e.g. gold/10400.
2193 Work around it by keeping stable sort order. */
2194 return (a
< b
) ? -1 : 1;
2196 /* Put eh_frame entries after debug_frame ones. */
2197 return aa
->eh_frame_p
- bb
->eh_frame_p
;
2200 return (aa
->initial_location
< bb
->initial_location
) ? -1 : 1;
2204 dwarf2_build_frame_info (struct objfile
*objfile
)
2206 struct comp_unit
*unit
;
2207 gdb_byte
*frame_ptr
;
2208 struct dwarf2_cie_table cie_table
;
2209 struct dwarf2_fde_table fde_table
;
2210 struct dwarf2_fde_table
*fde_table2
;
2212 cie_table
.num_entries
= 0;
2213 cie_table
.entries
= NULL
;
2215 fde_table
.num_entries
= 0;
2216 fde_table
.entries
= NULL
;
2218 /* Build a minimal decoding of the DWARF2 compilation unit. */
2219 unit
= (struct comp_unit
*) obstack_alloc (&objfile
->objfile_obstack
,
2220 sizeof (struct comp_unit
));
2221 unit
->abfd
= objfile
->obfd
;
2222 unit
->objfile
= objfile
;
2226 dwarf2_get_section_info (objfile
, ".eh_frame",
2227 &unit
->dwarf_frame_section
,
2228 &unit
->dwarf_frame_buffer
,
2229 &unit
->dwarf_frame_size
);
2230 if (unit
->dwarf_frame_size
)
2232 asection
*got
, *txt
;
2234 /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base
2235 that is used for the i386/amd64 target, which currently is
2236 the only target in GCC that supports/uses the
2237 DW_EH_PE_datarel encoding. */
2238 got
= bfd_get_section_by_name (unit
->abfd
, ".got");
2240 unit
->dbase
= got
->vma
;
2242 /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64
2244 txt
= bfd_get_section_by_name (unit
->abfd
, ".text");
2246 unit
->tbase
= txt
->vma
;
2248 frame_ptr
= unit
->dwarf_frame_buffer
;
2249 while (frame_ptr
< unit
->dwarf_frame_buffer
+ unit
->dwarf_frame_size
)
2250 frame_ptr
= decode_frame_entry (unit
, frame_ptr
, 1,
2251 &cie_table
, &fde_table
);
2253 if (cie_table
.num_entries
!= 0)
2255 /* Reinit cie_table: debug_frame has different CIEs. */
2256 xfree (cie_table
.entries
);
2257 cie_table
.num_entries
= 0;
2258 cie_table
.entries
= NULL
;
2262 dwarf2_get_section_info (objfile
, ".debug_frame",
2263 &unit
->dwarf_frame_section
,
2264 &unit
->dwarf_frame_buffer
,
2265 &unit
->dwarf_frame_size
);
2266 if (unit
->dwarf_frame_size
)
2268 frame_ptr
= unit
->dwarf_frame_buffer
;
2269 while (frame_ptr
< unit
->dwarf_frame_buffer
+ unit
->dwarf_frame_size
)
2270 frame_ptr
= decode_frame_entry (unit
, frame_ptr
, 0,
2271 &cie_table
, &fde_table
);
2274 /* Discard the cie_table, it is no longer needed. */
2275 if (cie_table
.num_entries
!= 0)
2277 xfree (cie_table
.entries
);
2278 cie_table
.entries
= NULL
; /* Paranoia. */
2279 cie_table
.num_entries
= 0; /* Paranoia. */
2282 /* Copy fde_table to obstack: it is needed at runtime. */
2283 fde_table2
= (struct dwarf2_fde_table
*)
2284 obstack_alloc (&objfile
->objfile_obstack
, sizeof (*fde_table2
));
2286 if (fde_table
.num_entries
== 0)
2288 fde_table2
->entries
= NULL
;
2289 fde_table2
->num_entries
= 0;
2293 struct dwarf2_fde
*fde_prev
= NULL
;
2294 struct dwarf2_fde
*first_non_zero_fde
= NULL
;
2297 /* Prepare FDE table for lookups. */
2298 qsort (fde_table
.entries
, fde_table
.num_entries
,
2299 sizeof (fde_table
.entries
[0]), qsort_fde_cmp
);
2301 /* Check for leftovers from --gc-sections. The GNU linker sets
2302 the relevant symbols to zero, but doesn't zero the FDE *end*
2303 ranges because there's no relocation there. It's (offset,
2304 length), not (start, end). On targets where address zero is
2305 just another valid address this can be a problem, since the
2306 FDEs appear to be non-empty in the output --- we could pick
2307 out the wrong FDE. To work around this, when overlaps are
2308 detected, we prefer FDEs that do not start at zero.
2310 Start by finding the first FDE with non-zero start. Below
2311 we'll discard all FDEs that start at zero and overlap this
2313 for (i
= 0; i
< fde_table
.num_entries
; i
++)
2315 struct dwarf2_fde
*fde
= fde_table
.entries
[i
];
2317 if (fde
->initial_location
!= 0)
2319 first_non_zero_fde
= fde
;
2324 /* Since we'll be doing bsearch, squeeze out identical (except
2325 for eh_frame_p) fde entries so bsearch result is predictable.
2326 Also discard leftovers from --gc-sections. */
2327 fde_table2
->num_entries
= 0;
2328 for (i
= 0; i
< fde_table
.num_entries
; i
++)
2330 struct dwarf2_fde
*fde
= fde_table
.entries
[i
];
2332 if (fde
->initial_location
== 0
2333 && first_non_zero_fde
!= NULL
2334 && (first_non_zero_fde
->initial_location
2335 < fde
->initial_location
+ fde
->address_range
))
2338 if (fde_prev
!= NULL
2339 && fde_prev
->initial_location
== fde
->initial_location
)
2342 obstack_grow (&objfile
->objfile_obstack
, &fde_table
.entries
[i
],
2343 sizeof (fde_table
.entries
[0]));
2344 ++fde_table2
->num_entries
;
2347 fde_table2
->entries
= obstack_finish (&objfile
->objfile_obstack
);
2349 /* Discard the original fde_table. */
2350 xfree (fde_table
.entries
);
2353 set_objfile_data (objfile
, dwarf2_frame_objfile_data
, fde_table2
);
2356 /* Provide a prototype to silence -Wmissing-prototypes. */
2357 void _initialize_dwarf2_frame (void);
2360 _initialize_dwarf2_frame (void)
2362 dwarf2_frame_data
= gdbarch_data_register_pre_init (dwarf2_frame_init
);
2363 dwarf2_frame_objfile_data
= register_objfile_data ();