Commit | Line | Data |
---|---|---|
cfc14b3a MK |
1 | /* Frame unwinder for frames with DWARF Call Frame Information. |
2 | ||
4c38e0a4 | 3 | Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010 |
0fb0cc75 | 4 | Free Software Foundation, Inc. |
cfc14b3a MK |
5 | |
6 | Contributed by Mark Kettenis. | |
7 | ||
8 | This file is part of GDB. | |
9 | ||
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 | |
a9762ec7 | 12 | the Free Software Foundation; either version 3 of the License, or |
cfc14b3a MK |
13 | (at your option) any later version. |
14 | ||
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. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
cfc14b3a MK |
22 | |
23 | #include "defs.h" | |
24 | #include "dwarf2expr.h" | |
fa8f86ff | 25 | #include "dwarf2.h" |
cfc14b3a MK |
26 | #include "frame.h" |
27 | #include "frame-base.h" | |
28 | #include "frame-unwind.h" | |
29 | #include "gdbcore.h" | |
30 | #include "gdbtypes.h" | |
31 | #include "symtab.h" | |
32 | #include "objfiles.h" | |
33 | #include "regcache.h" | |
f2da6b3a | 34 | #include "value.h" |
cfc14b3a MK |
35 | |
36 | #include "gdb_assert.h" | |
37 | #include "gdb_string.h" | |
38 | ||
6896c0c7 | 39 | #include "complaints.h" |
cfc14b3a MK |
40 | #include "dwarf2-frame.h" |
41 | ||
ae0d2f24 UW |
42 | struct comp_unit; |
43 | ||
cfc14b3a MK |
44 | /* Call Frame Information (CFI). */ |
45 | ||
46 | /* Common Information Entry (CIE). */ | |
47 | ||
48 | struct dwarf2_cie | |
49 | { | |
ae0d2f24 UW |
50 | /* Computation Unit for this CIE. */ |
51 | struct comp_unit *unit; | |
52 | ||
cfc14b3a MK |
53 | /* Offset into the .debug_frame section where this CIE was found. |
54 | Used to identify this CIE. */ | |
55 | ULONGEST cie_pointer; | |
56 | ||
57 | /* Constant that is factored out of all advance location | |
58 | instructions. */ | |
59 | ULONGEST code_alignment_factor; | |
60 | ||
61 | /* Constants that is factored out of all offset instructions. */ | |
62 | LONGEST data_alignment_factor; | |
63 | ||
64 | /* Return address column. */ | |
65 | ULONGEST return_address_register; | |
66 | ||
67 | /* Instruction sequence to initialize a register set. */ | |
852483bc MK |
68 | gdb_byte *initial_instructions; |
69 | gdb_byte *end; | |
cfc14b3a | 70 | |
303b6f5d DJ |
71 | /* Saved augmentation, in case it's needed later. */ |
72 | char *augmentation; | |
73 | ||
cfc14b3a | 74 | /* Encoding of addresses. */ |
852483bc | 75 | gdb_byte encoding; |
cfc14b3a | 76 | |
ae0d2f24 UW |
77 | /* Target address size in bytes. */ |
78 | int addr_size; | |
79 | ||
7131cb6e RH |
80 | /* True if a 'z' augmentation existed. */ |
81 | unsigned char saw_z_augmentation; | |
82 | ||
56c987f6 AO |
83 | /* True if an 'S' augmentation existed. */ |
84 | unsigned char signal_frame; | |
85 | ||
303b6f5d DJ |
86 | /* The version recorded in the CIE. */ |
87 | unsigned char version; | |
2dc7f7b3 TT |
88 | |
89 | /* The segment size. */ | |
90 | unsigned char segment_size; | |
b01c8410 | 91 | }; |
303b6f5d | 92 | |
b01c8410 PP |
93 | struct dwarf2_cie_table |
94 | { | |
95 | int num_entries; | |
96 | struct dwarf2_cie **entries; | |
cfc14b3a MK |
97 | }; |
98 | ||
99 | /* Frame Description Entry (FDE). */ | |
100 | ||
101 | struct dwarf2_fde | |
102 | { | |
103 | /* CIE for this FDE. */ | |
104 | struct dwarf2_cie *cie; | |
105 | ||
106 | /* First location associated with this FDE. */ | |
107 | CORE_ADDR initial_location; | |
108 | ||
109 | /* Number of bytes of program instructions described by this FDE. */ | |
110 | CORE_ADDR address_range; | |
111 | ||
112 | /* Instruction sequence. */ | |
852483bc MK |
113 | gdb_byte *instructions; |
114 | gdb_byte *end; | |
cfc14b3a | 115 | |
4bf8967c AS |
116 | /* True if this FDE is read from a .eh_frame instead of a .debug_frame |
117 | section. */ | |
118 | unsigned char eh_frame_p; | |
b01c8410 | 119 | }; |
4bf8967c | 120 | |
b01c8410 PP |
121 | struct dwarf2_fde_table |
122 | { | |
123 | int num_entries; | |
124 | struct dwarf2_fde **entries; | |
cfc14b3a MK |
125 | }; |
126 | ||
ae0d2f24 UW |
127 | /* A minimal decoding of DWARF2 compilation units. We only decode |
128 | what's needed to get to the call frame information. */ | |
129 | ||
130 | struct comp_unit | |
131 | { | |
132 | /* Keep the bfd convenient. */ | |
133 | bfd *abfd; | |
134 | ||
135 | struct objfile *objfile; | |
136 | ||
ae0d2f24 UW |
137 | /* Pointer to the .debug_frame section loaded into memory. */ |
138 | gdb_byte *dwarf_frame_buffer; | |
139 | ||
140 | /* Length of the loaded .debug_frame section. */ | |
c098b58b | 141 | bfd_size_type dwarf_frame_size; |
ae0d2f24 UW |
142 | |
143 | /* Pointer to the .debug_frame section. */ | |
144 | asection *dwarf_frame_section; | |
145 | ||
146 | /* Base for DW_EH_PE_datarel encodings. */ | |
147 | bfd_vma dbase; | |
148 | ||
149 | /* Base for DW_EH_PE_textrel encodings. */ | |
150 | bfd_vma tbase; | |
151 | }; | |
152 | ||
cfc14b3a | 153 | static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc); |
4fc771b8 DJ |
154 | |
155 | static int dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, | |
156 | int eh_frame_p); | |
ae0d2f24 UW |
157 | |
158 | static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding, | |
0d45f56e | 159 | int ptr_len, const gdb_byte *buf, |
ae0d2f24 UW |
160 | unsigned int *bytes_read_ptr, |
161 | CORE_ADDR func_base); | |
cfc14b3a MK |
162 | \f |
163 | ||
164 | /* Structure describing a frame state. */ | |
165 | ||
166 | struct dwarf2_frame_state | |
167 | { | |
168 | /* Each register save state can be described in terms of a CFA slot, | |
169 | another register, or a location expression. */ | |
170 | struct dwarf2_frame_state_reg_info | |
171 | { | |
05cbe71a | 172 | struct dwarf2_frame_state_reg *reg; |
cfc14b3a MK |
173 | int num_regs; |
174 | ||
2fd481e1 PP |
175 | LONGEST cfa_offset; |
176 | ULONGEST cfa_reg; | |
177 | enum { | |
178 | CFA_UNSET, | |
179 | CFA_REG_OFFSET, | |
180 | CFA_EXP | |
181 | } cfa_how; | |
0d45f56e | 182 | const gdb_byte *cfa_exp; |
2fd481e1 | 183 | |
cfc14b3a MK |
184 | /* Used to implement DW_CFA_remember_state. */ |
185 | struct dwarf2_frame_state_reg_info *prev; | |
186 | } regs; | |
187 | ||
cfc14b3a MK |
188 | /* The PC described by the current frame state. */ |
189 | CORE_ADDR pc; | |
190 | ||
191 | /* Initial register set from the CIE. | |
192 | Used to implement DW_CFA_restore. */ | |
193 | struct dwarf2_frame_state_reg_info initial; | |
194 | ||
195 | /* The information we care about from the CIE. */ | |
196 | LONGEST data_align; | |
197 | ULONGEST code_align; | |
198 | ULONGEST retaddr_column; | |
303b6f5d DJ |
199 | |
200 | /* Flags for known producer quirks. */ | |
201 | ||
202 | /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa | |
203 | and DW_CFA_def_cfa_offset takes a factored offset. */ | |
204 | int armcc_cfa_offsets_sf; | |
205 | ||
206 | /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that | |
207 | the CFA is defined as REG - OFFSET rather than REG + OFFSET. */ | |
208 | int armcc_cfa_offsets_reversed; | |
cfc14b3a MK |
209 | }; |
210 | ||
211 | /* Store the length the expression for the CFA in the `cfa_reg' field, | |
212 | which is unused in that case. */ | |
213 | #define cfa_exp_len cfa_reg | |
214 | ||
f57d151a | 215 | /* Assert that the register set RS is large enough to store gdbarch_num_regs |
cfc14b3a MK |
216 | columns. If necessary, enlarge the register set. */ |
217 | ||
218 | static void | |
219 | dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs, | |
220 | int num_regs) | |
221 | { | |
222 | size_t size = sizeof (struct dwarf2_frame_state_reg); | |
223 | ||
224 | if (num_regs <= rs->num_regs) | |
225 | return; | |
226 | ||
227 | rs->reg = (struct dwarf2_frame_state_reg *) | |
228 | xrealloc (rs->reg, num_regs * size); | |
229 | ||
230 | /* Initialize newly allocated registers. */ | |
2473a4a9 | 231 | memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size); |
cfc14b3a MK |
232 | rs->num_regs = num_regs; |
233 | } | |
234 | ||
235 | /* Copy the register columns in register set RS into newly allocated | |
236 | memory and return a pointer to this newly created copy. */ | |
237 | ||
238 | static struct dwarf2_frame_state_reg * | |
239 | dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs) | |
240 | { | |
d10891d4 | 241 | size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg); |
cfc14b3a MK |
242 | struct dwarf2_frame_state_reg *reg; |
243 | ||
244 | reg = (struct dwarf2_frame_state_reg *) xmalloc (size); | |
245 | memcpy (reg, rs->reg, size); | |
246 | ||
247 | return reg; | |
248 | } | |
249 | ||
250 | /* Release the memory allocated to register set RS. */ | |
251 | ||
252 | static void | |
253 | dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs) | |
254 | { | |
255 | if (rs) | |
256 | { | |
257 | dwarf2_frame_state_free_regs (rs->prev); | |
258 | ||
259 | xfree (rs->reg); | |
260 | xfree (rs); | |
261 | } | |
262 | } | |
263 | ||
264 | /* Release the memory allocated to the frame state FS. */ | |
265 | ||
266 | static void | |
267 | dwarf2_frame_state_free (void *p) | |
268 | { | |
269 | struct dwarf2_frame_state *fs = p; | |
270 | ||
271 | dwarf2_frame_state_free_regs (fs->initial.prev); | |
272 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
273 | xfree (fs->initial.reg); | |
274 | xfree (fs->regs.reg); | |
275 | xfree (fs); | |
276 | } | |
277 | \f | |
278 | ||
279 | /* Helper functions for execute_stack_op. */ | |
280 | ||
281 | static CORE_ADDR | |
282 | read_reg (void *baton, int reg) | |
283 | { | |
4a4e5149 DJ |
284 | struct frame_info *this_frame = (struct frame_info *) baton; |
285 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
cfc14b3a | 286 | int regnum; |
852483bc | 287 | gdb_byte *buf; |
cfc14b3a | 288 | |
ad010def | 289 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); |
cfc14b3a | 290 | |
852483bc | 291 | buf = alloca (register_size (gdbarch, regnum)); |
4a4e5149 | 292 | get_frame_register (this_frame, regnum, buf); |
f2da6b3a DJ |
293 | |
294 | /* Convert the register to an integer. This returns a LONGEST | |
295 | rather than a CORE_ADDR, but unpack_pointer does the same thing | |
296 | under the covers, and this makes more sense for non-pointer | |
297 | registers. Maybe read_reg and the associated interfaces should | |
298 | deal with "struct value" instead of CORE_ADDR. */ | |
299 | return unpack_long (register_type (gdbarch, regnum), buf); | |
cfc14b3a MK |
300 | } |
301 | ||
302 | static void | |
852483bc | 303 | read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
cfc14b3a MK |
304 | { |
305 | read_memory (addr, buf, len); | |
306 | } | |
307 | ||
308 | static void | |
0d45f56e | 309 | no_get_frame_base (void *baton, const gdb_byte **start, size_t *length) |
cfc14b3a MK |
310 | { |
311 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 312 | _("Support for DW_OP_fbreg is unimplemented")); |
cfc14b3a MK |
313 | } |
314 | ||
e7802207 TT |
315 | /* Helper function for execute_stack_op. */ |
316 | ||
317 | static CORE_ADDR | |
318 | no_get_frame_cfa (void *baton) | |
319 | { | |
320 | internal_error (__FILE__, __LINE__, | |
321 | _("Support for DW_OP_call_frame_cfa is unimplemented")); | |
322 | } | |
323 | ||
cfc14b3a MK |
324 | static CORE_ADDR |
325 | no_get_tls_address (void *baton, CORE_ADDR offset) | |
326 | { | |
327 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 328 | _("Support for DW_OP_GNU_push_tls_address is unimplemented")); |
cfc14b3a MK |
329 | } |
330 | ||
5c631832 JK |
331 | /* Helper function for execute_stack_op. */ |
332 | ||
333 | static void | |
334 | no_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset) | |
335 | { | |
336 | internal_error (__FILE__, __LINE__, | |
337 | _("Support for DW_OP_call* is invalid in CFI")); | |
338 | } | |
339 | ||
a6a5a945 LM |
340 | /* Execute the required actions for both the DW_CFA_restore and |
341 | DW_CFA_restore_extended instructions. */ | |
342 | static void | |
343 | dwarf2_restore_rule (struct gdbarch *gdbarch, ULONGEST reg_num, | |
344 | struct dwarf2_frame_state *fs, int eh_frame_p) | |
345 | { | |
346 | ULONGEST reg; | |
347 | ||
348 | gdb_assert (fs->initial.reg); | |
349 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg_num, eh_frame_p); | |
350 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
351 | ||
352 | /* Check if this register was explicitly initialized in the | |
353 | CIE initial instructions. If not, default the rule to | |
354 | UNSPECIFIED. */ | |
355 | if (reg < fs->initial.num_regs) | |
356 | fs->regs.reg[reg] = fs->initial.reg[reg]; | |
357 | else | |
358 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED; | |
359 | ||
360 | if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
361 | complaint (&symfile_complaints, _("\ | |
362 | incomplete CFI data; DW_CFA_restore unspecified\n\ | |
5af949e3 | 363 | register %s (#%d) at %s"), |
a6a5a945 LM |
364 | gdbarch_register_name |
365 | (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)), | |
366 | gdbarch_dwarf2_reg_to_regnum (gdbarch, reg), | |
5af949e3 | 367 | paddress (gdbarch, fs->pc)); |
a6a5a945 LM |
368 | } |
369 | ||
cfc14b3a | 370 | static CORE_ADDR |
0d45f56e | 371 | execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size, |
44353522 DE |
372 | struct frame_info *this_frame, CORE_ADDR initial, |
373 | int initial_in_stack_memory) | |
cfc14b3a MK |
374 | { |
375 | struct dwarf_expr_context *ctx; | |
376 | CORE_ADDR result; | |
4a227398 | 377 | struct cleanup *old_chain; |
cfc14b3a MK |
378 | |
379 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
380 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
381 | ||
f7fd4728 | 382 | ctx->gdbarch = get_frame_arch (this_frame); |
ae0d2f24 | 383 | ctx->addr_size = addr_size; |
4a4e5149 | 384 | ctx->baton = this_frame; |
cfc14b3a MK |
385 | ctx->read_reg = read_reg; |
386 | ctx->read_mem = read_mem; | |
387 | ctx->get_frame_base = no_get_frame_base; | |
e7802207 | 388 | ctx->get_frame_cfa = no_get_frame_cfa; |
cfc14b3a | 389 | ctx->get_tls_address = no_get_tls_address; |
5c631832 | 390 | ctx->dwarf_call = no_dwarf_call; |
cfc14b3a | 391 | |
44353522 | 392 | dwarf_expr_push (ctx, initial, initial_in_stack_memory); |
cfc14b3a MK |
393 | dwarf_expr_eval (ctx, exp, len); |
394 | result = dwarf_expr_fetch (ctx, 0); | |
395 | ||
cec03d70 | 396 | if (ctx->location == DWARF_VALUE_REGISTER) |
4a4e5149 | 397 | result = read_reg (this_frame, result); |
cec03d70 TT |
398 | else if (ctx->location != DWARF_VALUE_MEMORY) |
399 | { | |
400 | /* This is actually invalid DWARF, but if we ever do run across | |
401 | it somehow, we might as well support it. So, instead, report | |
402 | it as unimplemented. */ | |
403 | error (_("Not implemented: computing unwound register using explicit value operator")); | |
404 | } | |
cfc14b3a | 405 | |
4a227398 | 406 | do_cleanups (old_chain); |
cfc14b3a MK |
407 | |
408 | return result; | |
409 | } | |
410 | \f | |
411 | ||
412 | static void | |
0d45f56e TT |
413 | execute_cfa_program (struct dwarf2_fde *fde, const gdb_byte *insn_ptr, |
414 | const gdb_byte *insn_end, struct frame_info *this_frame, | |
ae0d2f24 | 415 | struct dwarf2_frame_state *fs) |
cfc14b3a | 416 | { |
ae0d2f24 | 417 | int eh_frame_p = fde->eh_frame_p; |
4a4e5149 | 418 | CORE_ADDR pc = get_frame_pc (this_frame); |
cfc14b3a | 419 | int bytes_read; |
4a4e5149 | 420 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
e17a4113 | 421 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
cfc14b3a MK |
422 | |
423 | while (insn_ptr < insn_end && fs->pc <= pc) | |
424 | { | |
852483bc | 425 | gdb_byte insn = *insn_ptr++; |
cfc14b3a MK |
426 | ULONGEST utmp, reg; |
427 | LONGEST offset; | |
428 | ||
429 | if ((insn & 0xc0) == DW_CFA_advance_loc) | |
430 | fs->pc += (insn & 0x3f) * fs->code_align; | |
431 | else if ((insn & 0xc0) == DW_CFA_offset) | |
432 | { | |
433 | reg = insn & 0x3f; | |
4fc771b8 | 434 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
435 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
436 | offset = utmp * fs->data_align; | |
437 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 438 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
439 | fs->regs.reg[reg].loc.offset = offset; |
440 | } | |
441 | else if ((insn & 0xc0) == DW_CFA_restore) | |
442 | { | |
cfc14b3a | 443 | reg = insn & 0x3f; |
a6a5a945 | 444 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
445 | } |
446 | else | |
447 | { | |
448 | switch (insn) | |
449 | { | |
450 | case DW_CFA_set_loc: | |
ae0d2f24 UW |
451 | fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding, |
452 | fde->cie->addr_size, insn_ptr, | |
453 | &bytes_read, fde->initial_location); | |
454 | /* Apply the objfile offset for relocatable objects. */ | |
455 | fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets, | |
456 | SECT_OFF_TEXT (fde->cie->unit->objfile)); | |
cfc14b3a MK |
457 | insn_ptr += bytes_read; |
458 | break; | |
459 | ||
460 | case DW_CFA_advance_loc1: | |
e17a4113 | 461 | utmp = extract_unsigned_integer (insn_ptr, 1, byte_order); |
cfc14b3a MK |
462 | fs->pc += utmp * fs->code_align; |
463 | insn_ptr++; | |
464 | break; | |
465 | case DW_CFA_advance_loc2: | |
e17a4113 | 466 | utmp = extract_unsigned_integer (insn_ptr, 2, byte_order); |
cfc14b3a MK |
467 | fs->pc += utmp * fs->code_align; |
468 | insn_ptr += 2; | |
469 | break; | |
470 | case DW_CFA_advance_loc4: | |
e17a4113 | 471 | utmp = extract_unsigned_integer (insn_ptr, 4, byte_order); |
cfc14b3a MK |
472 | fs->pc += utmp * fs->code_align; |
473 | insn_ptr += 4; | |
474 | break; | |
475 | ||
476 | case DW_CFA_offset_extended: | |
477 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 478 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
479 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
480 | offset = utmp * fs->data_align; | |
481 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 482 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
483 | fs->regs.reg[reg].loc.offset = offset; |
484 | break; | |
485 | ||
486 | case DW_CFA_restore_extended: | |
cfc14b3a | 487 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); |
a6a5a945 | 488 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
489 | break; |
490 | ||
491 | case DW_CFA_undefined: | |
492 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 493 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 494 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 495 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED; |
cfc14b3a MK |
496 | break; |
497 | ||
498 | case DW_CFA_same_value: | |
499 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 500 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 501 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 502 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE; |
cfc14b3a MK |
503 | break; |
504 | ||
505 | case DW_CFA_register: | |
506 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 507 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 508 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
4fc771b8 | 509 | utmp = dwarf2_frame_adjust_regnum (gdbarch, utmp, eh_frame_p); |
cfc14b3a | 510 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 511 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; |
cfc14b3a MK |
512 | fs->regs.reg[reg].loc.reg = utmp; |
513 | break; | |
514 | ||
515 | case DW_CFA_remember_state: | |
516 | { | |
517 | struct dwarf2_frame_state_reg_info *new_rs; | |
518 | ||
519 | new_rs = XMALLOC (struct dwarf2_frame_state_reg_info); | |
520 | *new_rs = fs->regs; | |
521 | fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
522 | fs->regs.prev = new_rs; | |
523 | } | |
524 | break; | |
525 | ||
526 | case DW_CFA_restore_state: | |
527 | { | |
528 | struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev; | |
529 | ||
50ea7769 MK |
530 | if (old_rs == NULL) |
531 | { | |
e2e0b3e5 | 532 | complaint (&symfile_complaints, _("\ |
5af949e3 UW |
533 | bad CFI data; mismatched DW_CFA_restore_state at %s"), |
534 | paddress (gdbarch, fs->pc)); | |
50ea7769 MK |
535 | } |
536 | else | |
537 | { | |
538 | xfree (fs->regs.reg); | |
539 | fs->regs = *old_rs; | |
540 | xfree (old_rs); | |
541 | } | |
cfc14b3a MK |
542 | } |
543 | break; | |
544 | ||
545 | case DW_CFA_def_cfa: | |
2fd481e1 | 546 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
cfc14b3a | 547 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
548 | |
549 | if (fs->armcc_cfa_offsets_sf) | |
550 | utmp *= fs->data_align; | |
551 | ||
2fd481e1 PP |
552 | fs->regs.cfa_offset = utmp; |
553 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
554 | break; |
555 | ||
556 | case DW_CFA_def_cfa_register: | |
2fd481e1 PP |
557 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
558 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
559 | fs->regs.cfa_reg, | |
560 | eh_frame_p); | |
561 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
562 | break; |
563 | ||
564 | case DW_CFA_def_cfa_offset: | |
852483bc | 565 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
566 | |
567 | if (fs->armcc_cfa_offsets_sf) | |
568 | utmp *= fs->data_align; | |
569 | ||
2fd481e1 | 570 | fs->regs.cfa_offset = utmp; |
cfc14b3a MK |
571 | /* cfa_how deliberately not set. */ |
572 | break; | |
573 | ||
a8504492 MK |
574 | case DW_CFA_nop: |
575 | break; | |
576 | ||
cfc14b3a | 577 | case DW_CFA_def_cfa_expression: |
2fd481e1 PP |
578 | insn_ptr = read_uleb128 (insn_ptr, insn_end, |
579 | &fs->regs.cfa_exp_len); | |
580 | fs->regs.cfa_exp = insn_ptr; | |
581 | fs->regs.cfa_how = CFA_EXP; | |
582 | insn_ptr += fs->regs.cfa_exp_len; | |
cfc14b3a MK |
583 | break; |
584 | ||
585 | case DW_CFA_expression: | |
586 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 587 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
588 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
589 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
590 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
591 | fs->regs.reg[reg].exp_len = utmp; | |
05cbe71a | 592 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP; |
cfc14b3a MK |
593 | insn_ptr += utmp; |
594 | break; | |
595 | ||
a8504492 MK |
596 | case DW_CFA_offset_extended_sf: |
597 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 598 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
a8504492 | 599 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
f6da8dd8 | 600 | offset *= fs->data_align; |
a8504492 | 601 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 602 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
a8504492 MK |
603 | fs->regs.reg[reg].loc.offset = offset; |
604 | break; | |
605 | ||
46ea248b AO |
606 | case DW_CFA_val_offset: |
607 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
608 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
609 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
610 | offset = utmp * fs->data_align; | |
611 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
612 | fs->regs.reg[reg].loc.offset = offset; | |
613 | break; | |
614 | ||
615 | case DW_CFA_val_offset_sf: | |
616 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
617 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
618 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
619 | offset *= fs->data_align; | |
620 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
621 | fs->regs.reg[reg].loc.offset = offset; | |
622 | break; | |
623 | ||
624 | case DW_CFA_val_expression: | |
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 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
629 | fs->regs.reg[reg].exp_len = utmp; | |
630 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_EXP; | |
631 | insn_ptr += utmp; | |
632 | break; | |
633 | ||
a8504492 | 634 | case DW_CFA_def_cfa_sf: |
2fd481e1 PP |
635 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
636 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
637 | fs->regs.cfa_reg, | |
638 | eh_frame_p); | |
a8504492 | 639 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
2fd481e1 PP |
640 | fs->regs.cfa_offset = offset * fs->data_align; |
641 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
a8504492 MK |
642 | break; |
643 | ||
644 | case DW_CFA_def_cfa_offset_sf: | |
645 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
2fd481e1 | 646 | fs->regs.cfa_offset = offset * fs->data_align; |
a8504492 | 647 | /* cfa_how deliberately not set. */ |
cfc14b3a MK |
648 | break; |
649 | ||
a77f4086 MK |
650 | case DW_CFA_GNU_window_save: |
651 | /* This is SPARC-specific code, and contains hard-coded | |
652 | constants for the register numbering scheme used by | |
653 | GCC. Rather than having a architecture-specific | |
654 | operation that's only ever used by a single | |
655 | architecture, we provide the implementation here. | |
656 | Incidentally that's what GCC does too in its | |
657 | unwinder. */ | |
658 | { | |
4a4e5149 | 659 | int size = register_size (gdbarch, 0); |
9a619af0 | 660 | |
a77f4086 MK |
661 | dwarf2_frame_state_alloc_regs (&fs->regs, 32); |
662 | for (reg = 8; reg < 16; reg++) | |
663 | { | |
664 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; | |
665 | fs->regs.reg[reg].loc.reg = reg + 16; | |
666 | } | |
667 | for (reg = 16; reg < 32; reg++) | |
668 | { | |
669 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
670 | fs->regs.reg[reg].loc.offset = (reg - 16) * size; | |
671 | } | |
672 | } | |
673 | break; | |
674 | ||
cfc14b3a MK |
675 | case DW_CFA_GNU_args_size: |
676 | /* Ignored. */ | |
677 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
678 | break; | |
679 | ||
58894217 JK |
680 | case DW_CFA_GNU_negative_offset_extended: |
681 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 682 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
58894217 JK |
683 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &offset); |
684 | offset *= fs->data_align; | |
685 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
686 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
687 | fs->regs.reg[reg].loc.offset = -offset; | |
688 | break; | |
689 | ||
cfc14b3a | 690 | default: |
e2e0b3e5 | 691 | internal_error (__FILE__, __LINE__, _("Unknown CFI encountered.")); |
cfc14b3a MK |
692 | } |
693 | } | |
694 | } | |
695 | ||
696 | /* Don't allow remember/restore between CIE and FDE programs. */ | |
697 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
698 | fs->regs.prev = NULL; | |
699 | } | |
8f22cb90 | 700 | \f |
cfc14b3a | 701 | |
8f22cb90 | 702 | /* Architecture-specific operations. */ |
cfc14b3a | 703 | |
8f22cb90 MK |
704 | /* Per-architecture data key. */ |
705 | static struct gdbarch_data *dwarf2_frame_data; | |
706 | ||
707 | struct dwarf2_frame_ops | |
708 | { | |
709 | /* Pre-initialize the register state REG for register REGNUM. */ | |
aff37fc1 DM |
710 | void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *, |
711 | struct frame_info *); | |
3ed09a32 | 712 | |
4a4e5149 | 713 | /* Check whether the THIS_FRAME is a signal trampoline. */ |
3ed09a32 | 714 | int (*signal_frame_p) (struct gdbarch *, struct frame_info *); |
4bf8967c | 715 | |
4fc771b8 DJ |
716 | /* Convert .eh_frame register number to DWARF register number, or |
717 | adjust .debug_frame register number. */ | |
718 | int (*adjust_regnum) (struct gdbarch *, int, int); | |
cfc14b3a MK |
719 | }; |
720 | ||
8f22cb90 MK |
721 | /* Default architecture-specific register state initialization |
722 | function. */ | |
723 | ||
724 | static void | |
725 | dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 726 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 727 | struct frame_info *this_frame) |
8f22cb90 MK |
728 | { |
729 | /* If we have a register that acts as a program counter, mark it as | |
730 | a destination for the return address. If we have a register that | |
731 | serves as the stack pointer, arrange for it to be filled with the | |
732 | call frame address (CFA). The other registers are marked as | |
733 | unspecified. | |
734 | ||
735 | We copy the return address to the program counter, since many | |
736 | parts in GDB assume that it is possible to get the return address | |
737 | by unwinding the program counter register. However, on ISA's | |
738 | with a dedicated return address register, the CFI usually only | |
739 | contains information to unwind that return address register. | |
740 | ||
741 | The reason we're treating the stack pointer special here is | |
742 | because in many cases GCC doesn't emit CFI for the stack pointer | |
743 | and implicitly assumes that it is equal to the CFA. This makes | |
744 | some sense since the DWARF specification (version 3, draft 8, | |
745 | p. 102) says that: | |
746 | ||
747 | "Typically, the CFA is defined to be the value of the stack | |
748 | pointer at the call site in the previous frame (which may be | |
749 | different from its value on entry to the current frame)." | |
750 | ||
751 | However, this isn't true for all platforms supported by GCC | |
752 | (e.g. IBM S/390 and zSeries). Those architectures should provide | |
753 | their own architecture-specific initialization function. */ | |
05cbe71a | 754 | |
ad010def | 755 | if (regnum == gdbarch_pc_regnum (gdbarch)) |
8f22cb90 | 756 | reg->how = DWARF2_FRAME_REG_RA; |
ad010def | 757 | else if (regnum == gdbarch_sp_regnum (gdbarch)) |
8f22cb90 MK |
758 | reg->how = DWARF2_FRAME_REG_CFA; |
759 | } | |
05cbe71a | 760 | |
8f22cb90 | 761 | /* Return a default for the architecture-specific operations. */ |
05cbe71a | 762 | |
8f22cb90 | 763 | static void * |
030f20e1 | 764 | dwarf2_frame_init (struct obstack *obstack) |
8f22cb90 MK |
765 | { |
766 | struct dwarf2_frame_ops *ops; | |
767 | ||
030f20e1 | 768 | ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops); |
8f22cb90 MK |
769 | ops->init_reg = dwarf2_frame_default_init_reg; |
770 | return ops; | |
771 | } | |
05cbe71a | 772 | |
8f22cb90 MK |
773 | /* Set the architecture-specific register state initialization |
774 | function for GDBARCH to INIT_REG. */ | |
775 | ||
776 | void | |
777 | dwarf2_frame_set_init_reg (struct gdbarch *gdbarch, | |
778 | void (*init_reg) (struct gdbarch *, int, | |
aff37fc1 DM |
779 | struct dwarf2_frame_state_reg *, |
780 | struct frame_info *)) | |
8f22cb90 | 781 | { |
030f20e1 | 782 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 783 | |
8f22cb90 MK |
784 | ops->init_reg = init_reg; |
785 | } | |
786 | ||
787 | /* Pre-initialize the register state REG for register REGNUM. */ | |
05cbe71a MK |
788 | |
789 | static void | |
790 | dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 791 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 792 | struct frame_info *this_frame) |
05cbe71a | 793 | { |
030f20e1 | 794 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 795 | |
4a4e5149 | 796 | ops->init_reg (gdbarch, regnum, reg, this_frame); |
05cbe71a | 797 | } |
3ed09a32 DJ |
798 | |
799 | /* Set the architecture-specific signal trampoline recognition | |
800 | function for GDBARCH to SIGNAL_FRAME_P. */ | |
801 | ||
802 | void | |
803 | dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch, | |
804 | int (*signal_frame_p) (struct gdbarch *, | |
805 | struct frame_info *)) | |
806 | { | |
807 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
808 | ||
809 | ops->signal_frame_p = signal_frame_p; | |
810 | } | |
811 | ||
812 | /* Query the architecture-specific signal frame recognizer for | |
4a4e5149 | 813 | THIS_FRAME. */ |
3ed09a32 DJ |
814 | |
815 | static int | |
816 | dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch, | |
4a4e5149 | 817 | struct frame_info *this_frame) |
3ed09a32 DJ |
818 | { |
819 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
820 | ||
821 | if (ops->signal_frame_p == NULL) | |
822 | return 0; | |
4a4e5149 | 823 | return ops->signal_frame_p (gdbarch, this_frame); |
3ed09a32 | 824 | } |
4bf8967c | 825 | |
4fc771b8 DJ |
826 | /* Set the architecture-specific adjustment of .eh_frame and .debug_frame |
827 | register numbers. */ | |
4bf8967c AS |
828 | |
829 | void | |
4fc771b8 DJ |
830 | dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch, |
831 | int (*adjust_regnum) (struct gdbarch *, | |
832 | int, int)) | |
4bf8967c AS |
833 | { |
834 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
835 | ||
4fc771b8 | 836 | ops->adjust_regnum = adjust_regnum; |
4bf8967c AS |
837 | } |
838 | ||
4fc771b8 DJ |
839 | /* Translate a .eh_frame register to DWARF register, or adjust a .debug_frame |
840 | register. */ | |
4bf8967c | 841 | |
4fc771b8 DJ |
842 | static int |
843 | dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, int eh_frame_p) | |
4bf8967c AS |
844 | { |
845 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
846 | ||
4fc771b8 | 847 | if (ops->adjust_regnum == NULL) |
4bf8967c | 848 | return regnum; |
4fc771b8 | 849 | return ops->adjust_regnum (gdbarch, regnum, eh_frame_p); |
4bf8967c | 850 | } |
303b6f5d DJ |
851 | |
852 | static void | |
853 | dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs, | |
854 | struct dwarf2_fde *fde) | |
855 | { | |
303b6f5d DJ |
856 | struct symtab *s; |
857 | ||
858 | s = find_pc_symtab (fs->pc); | |
a6c727b2 | 859 | if (s == NULL) |
303b6f5d DJ |
860 | return; |
861 | ||
a6c727b2 DJ |
862 | if (producer_is_realview (s->producer)) |
863 | { | |
864 | if (fde->cie->version == 1) | |
865 | fs->armcc_cfa_offsets_sf = 1; | |
866 | ||
867 | if (fde->cie->version == 1) | |
868 | fs->armcc_cfa_offsets_reversed = 1; | |
869 | ||
870 | /* The reversed offset problem is present in some compilers | |
871 | using DWARF3, but it was eventually fixed. Check the ARM | |
872 | defined augmentations, which are in the format "armcc" followed | |
873 | by a list of one-character options. The "+" option means | |
874 | this problem is fixed (no quirk needed). If the armcc | |
875 | augmentation is missing, the quirk is needed. */ | |
876 | if (fde->cie->version == 3 | |
877 | && (strncmp (fde->cie->augmentation, "armcc", 5) != 0 | |
878 | || strchr (fde->cie->augmentation + 5, '+') == NULL)) | |
879 | fs->armcc_cfa_offsets_reversed = 1; | |
880 | ||
881 | return; | |
882 | } | |
303b6f5d | 883 | } |
8f22cb90 MK |
884 | \f |
885 | ||
886 | struct dwarf2_frame_cache | |
887 | { | |
888 | /* DWARF Call Frame Address. */ | |
889 | CORE_ADDR cfa; | |
890 | ||
0228dfb9 DJ |
891 | /* Set if the return address column was marked as undefined. */ |
892 | int undefined_retaddr; | |
893 | ||
8f22cb90 MK |
894 | /* Saved registers, indexed by GDB register number, not by DWARF |
895 | register number. */ | |
896 | struct dwarf2_frame_state_reg *reg; | |
8d5a9abc MK |
897 | |
898 | /* Return address register. */ | |
899 | struct dwarf2_frame_state_reg retaddr_reg; | |
ae0d2f24 UW |
900 | |
901 | /* Target address size in bytes. */ | |
902 | int addr_size; | |
8f22cb90 | 903 | }; |
05cbe71a | 904 | |
b9362cc7 | 905 | static struct dwarf2_frame_cache * |
4a4e5149 | 906 | dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
907 | { |
908 | struct cleanup *old_chain; | |
4a4e5149 | 909 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
ad010def UW |
910 | const int num_regs = gdbarch_num_regs (gdbarch) |
911 | + gdbarch_num_pseudo_regs (gdbarch); | |
cfc14b3a MK |
912 | struct dwarf2_frame_cache *cache; |
913 | struct dwarf2_frame_state *fs; | |
914 | struct dwarf2_fde *fde; | |
cfc14b3a MK |
915 | |
916 | if (*this_cache) | |
917 | return *this_cache; | |
918 | ||
919 | /* Allocate a new cache. */ | |
920 | cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache); | |
921 | cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg); | |
922 | ||
923 | /* Allocate and initialize the frame state. */ | |
924 | fs = XMALLOC (struct dwarf2_frame_state); | |
925 | memset (fs, 0, sizeof (struct dwarf2_frame_state)); | |
926 | old_chain = make_cleanup (dwarf2_frame_state_free, fs); | |
927 | ||
928 | /* Unwind the PC. | |
929 | ||
4a4e5149 | 930 | Note that if the next frame is never supposed to return (i.e. a call |
cfc14b3a | 931 | to abort), the compiler might optimize away the instruction at |
4a4e5149 | 932 | its return address. As a result the return address will |
cfc14b3a | 933 | point at some random instruction, and the CFI for that |
e4e9607c | 934 | instruction is probably worthless to us. GCC's unwinder solves |
cfc14b3a MK |
935 | this problem by substracting 1 from the return address to get an |
936 | address in the middle of a presumed call instruction (or the | |
937 | instruction in the associated delay slot). This should only be | |
938 | done for "normal" frames and not for resume-type frames (signal | |
e4e9607c | 939 | handlers, sentinel frames, dummy frames). The function |
ad1193e7 | 940 | get_frame_address_in_block does just this. It's not clear how |
e4e9607c MK |
941 | reliable the method is though; there is the potential for the |
942 | register state pre-call being different to that on return. */ | |
4a4e5149 | 943 | fs->pc = get_frame_address_in_block (this_frame); |
cfc14b3a MK |
944 | |
945 | /* Find the correct FDE. */ | |
946 | fde = dwarf2_frame_find_fde (&fs->pc); | |
947 | gdb_assert (fde != NULL); | |
948 | ||
949 | /* Extract any interesting information from the CIE. */ | |
950 | fs->data_align = fde->cie->data_alignment_factor; | |
951 | fs->code_align = fde->cie->code_alignment_factor; | |
952 | fs->retaddr_column = fde->cie->return_address_register; | |
ae0d2f24 | 953 | cache->addr_size = fde->cie->addr_size; |
cfc14b3a | 954 | |
303b6f5d DJ |
955 | /* Check for "quirks" - known bugs in producers. */ |
956 | dwarf2_frame_find_quirks (fs, fde); | |
957 | ||
cfc14b3a | 958 | /* First decode all the insns in the CIE. */ |
ae0d2f24 | 959 | execute_cfa_program (fde, fde->cie->initial_instructions, |
4a4e5149 | 960 | fde->cie->end, this_frame, fs); |
cfc14b3a MK |
961 | |
962 | /* Save the initialized register set. */ | |
963 | fs->initial = fs->regs; | |
964 | fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
965 | ||
966 | /* Then decode the insns in the FDE up to our target PC. */ | |
4a4e5149 | 967 | execute_cfa_program (fde, fde->instructions, fde->end, this_frame, fs); |
cfc14b3a | 968 | |
938f5214 | 969 | /* Calculate the CFA. */ |
2fd481e1 | 970 | switch (fs->regs.cfa_how) |
cfc14b3a MK |
971 | { |
972 | case CFA_REG_OFFSET: | |
2fd481e1 | 973 | cache->cfa = read_reg (this_frame, fs->regs.cfa_reg); |
303b6f5d | 974 | if (fs->armcc_cfa_offsets_reversed) |
2fd481e1 | 975 | cache->cfa -= fs->regs.cfa_offset; |
303b6f5d | 976 | else |
2fd481e1 | 977 | cache->cfa += fs->regs.cfa_offset; |
cfc14b3a MK |
978 | break; |
979 | ||
980 | case CFA_EXP: | |
981 | cache->cfa = | |
2fd481e1 | 982 | execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len, |
44353522 | 983 | cache->addr_size, this_frame, 0, 0); |
cfc14b3a MK |
984 | break; |
985 | ||
986 | default: | |
e2e0b3e5 | 987 | internal_error (__FILE__, __LINE__, _("Unknown CFA rule.")); |
cfc14b3a MK |
988 | } |
989 | ||
05cbe71a | 990 | /* Initialize the register state. */ |
3e2c4033 AC |
991 | { |
992 | int regnum; | |
e4e9607c | 993 | |
3e2c4033 | 994 | for (regnum = 0; regnum < num_regs; regnum++) |
4a4e5149 | 995 | dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], this_frame); |
3e2c4033 AC |
996 | } |
997 | ||
998 | /* Go through the DWARF2 CFI generated table and save its register | |
79c4cb80 MK |
999 | location information in the cache. Note that we don't skip the |
1000 | return address column; it's perfectly all right for it to | |
1001 | correspond to a real register. If it doesn't correspond to a | |
1002 | real register, or if we shouldn't treat it as such, | |
055d23b8 | 1003 | gdbarch_dwarf2_reg_to_regnum should be defined to return a number outside |
f57d151a | 1004 | the range [0, gdbarch_num_regs). */ |
3e2c4033 AC |
1005 | { |
1006 | int column; /* CFI speak for "register number". */ | |
e4e9607c | 1007 | |
3e2c4033 AC |
1008 | for (column = 0; column < fs->regs.num_regs; column++) |
1009 | { | |
3e2c4033 | 1010 | /* Use the GDB register number as the destination index. */ |
ad010def | 1011 | int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column); |
3e2c4033 AC |
1012 | |
1013 | /* If there's no corresponding GDB register, ignore it. */ | |
1014 | if (regnum < 0 || regnum >= num_regs) | |
1015 | continue; | |
1016 | ||
1017 | /* NOTE: cagney/2003-09-05: CFI should specify the disposition | |
e4e9607c MK |
1018 | of all debug info registers. If it doesn't, complain (but |
1019 | not too loudly). It turns out that GCC assumes that an | |
3e2c4033 AC |
1020 | unspecified register implies "same value" when CFI (draft |
1021 | 7) specifies nothing at all. Such a register could equally | |
1022 | be interpreted as "undefined". Also note that this check | |
e4e9607c MK |
1023 | isn't sufficient; it only checks that all registers in the |
1024 | range [0 .. max column] are specified, and won't detect | |
3e2c4033 | 1025 | problems when a debug info register falls outside of the |
e4e9607c | 1026 | table. We need a way of iterating through all the valid |
3e2c4033 | 1027 | DWARF2 register numbers. */ |
05cbe71a | 1028 | if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED) |
f059bf6f AC |
1029 | { |
1030 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
e2e0b3e5 | 1031 | complaint (&symfile_complaints, _("\ |
5af949e3 | 1032 | incomplete CFI data; unspecified registers (e.g., %s) at %s"), |
f059bf6f | 1033 | gdbarch_register_name (gdbarch, regnum), |
5af949e3 | 1034 | paddress (gdbarch, fs->pc)); |
f059bf6f | 1035 | } |
35889917 MK |
1036 | else |
1037 | cache->reg[regnum] = fs->regs.reg[column]; | |
3e2c4033 AC |
1038 | } |
1039 | } | |
cfc14b3a | 1040 | |
8d5a9abc MK |
1041 | /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information |
1042 | we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */ | |
35889917 MK |
1043 | { |
1044 | int regnum; | |
1045 | ||
1046 | for (regnum = 0; regnum < num_regs; regnum++) | |
1047 | { | |
8d5a9abc MK |
1048 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA |
1049 | || cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET) | |
35889917 | 1050 | { |
05cbe71a MK |
1051 | struct dwarf2_frame_state_reg *retaddr_reg = |
1052 | &fs->regs.reg[fs->retaddr_column]; | |
1053 | ||
d4f10bf2 MK |
1054 | /* It seems rather bizarre to specify an "empty" column as |
1055 | the return adress column. However, this is exactly | |
1056 | what GCC does on some targets. It turns out that GCC | |
1057 | assumes that the return address can be found in the | |
1058 | register corresponding to the return address column. | |
8d5a9abc MK |
1059 | Incidentally, that's how we should treat a return |
1060 | address column specifying "same value" too. */ | |
d4f10bf2 | 1061 | if (fs->retaddr_column < fs->regs.num_regs |
05cbe71a MK |
1062 | && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED |
1063 | && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE) | |
8d5a9abc MK |
1064 | { |
1065 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) | |
1066 | cache->reg[regnum] = *retaddr_reg; | |
1067 | else | |
1068 | cache->retaddr_reg = *retaddr_reg; | |
1069 | } | |
35889917 MK |
1070 | else |
1071 | { | |
8d5a9abc MK |
1072 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) |
1073 | { | |
1074 | cache->reg[regnum].loc.reg = fs->retaddr_column; | |
1075 | cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG; | |
1076 | } | |
1077 | else | |
1078 | { | |
1079 | cache->retaddr_reg.loc.reg = fs->retaddr_column; | |
1080 | cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG; | |
1081 | } | |
35889917 MK |
1082 | } |
1083 | } | |
1084 | } | |
1085 | } | |
cfc14b3a | 1086 | |
0228dfb9 DJ |
1087 | if (fs->retaddr_column < fs->regs.num_regs |
1088 | && fs->regs.reg[fs->retaddr_column].how == DWARF2_FRAME_REG_UNDEFINED) | |
1089 | cache->undefined_retaddr = 1; | |
1090 | ||
cfc14b3a MK |
1091 | do_cleanups (old_chain); |
1092 | ||
1093 | *this_cache = cache; | |
1094 | return cache; | |
1095 | } | |
1096 | ||
1097 | static void | |
4a4e5149 | 1098 | dwarf2_frame_this_id (struct frame_info *this_frame, void **this_cache, |
cfc14b3a MK |
1099 | struct frame_id *this_id) |
1100 | { | |
1101 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1102 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a | 1103 | |
0228dfb9 DJ |
1104 | if (cache->undefined_retaddr) |
1105 | return; | |
1106 | ||
4a4e5149 | 1107 | (*this_id) = frame_id_build (cache->cfa, get_frame_func (this_frame)); |
93d42b30 DJ |
1108 | } |
1109 | ||
4a4e5149 DJ |
1110 | static struct value * |
1111 | dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache, | |
1112 | int regnum) | |
93d42b30 | 1113 | { |
4a4e5149 | 1114 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
93d42b30 | 1115 | struct dwarf2_frame_cache *cache = |
4a4e5149 DJ |
1116 | dwarf2_frame_cache (this_frame, this_cache); |
1117 | CORE_ADDR addr; | |
1118 | int realnum; | |
cfc14b3a MK |
1119 | |
1120 | switch (cache->reg[regnum].how) | |
1121 | { | |
05cbe71a | 1122 | case DWARF2_FRAME_REG_UNDEFINED: |
3e2c4033 | 1123 | /* If CFI explicitly specified that the value isn't defined, |
e4e9607c | 1124 | mark it as optimized away; the value isn't available. */ |
4a4e5149 | 1125 | return frame_unwind_got_optimized (this_frame, regnum); |
cfc14b3a | 1126 | |
05cbe71a | 1127 | case DWARF2_FRAME_REG_SAVED_OFFSET: |
4a4e5149 DJ |
1128 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1129 | return frame_unwind_got_memory (this_frame, regnum, addr); | |
cfc14b3a | 1130 | |
05cbe71a | 1131 | case DWARF2_FRAME_REG_SAVED_REG: |
4a4e5149 DJ |
1132 | realnum |
1133 | = gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg); | |
1134 | return frame_unwind_got_register (this_frame, regnum, realnum); | |
cfc14b3a | 1135 | |
05cbe71a | 1136 | case DWARF2_FRAME_REG_SAVED_EXP: |
4a4e5149 DJ |
1137 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1138 | cache->reg[regnum].exp_len, | |
44353522 | 1139 | cache->addr_size, this_frame, cache->cfa, 1); |
4a4e5149 | 1140 | return frame_unwind_got_memory (this_frame, regnum, addr); |
cfc14b3a | 1141 | |
46ea248b | 1142 | case DWARF2_FRAME_REG_SAVED_VAL_OFFSET: |
4a4e5149 DJ |
1143 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1144 | return frame_unwind_got_constant (this_frame, regnum, addr); | |
46ea248b AO |
1145 | |
1146 | case DWARF2_FRAME_REG_SAVED_VAL_EXP: | |
4a4e5149 DJ |
1147 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1148 | cache->reg[regnum].exp_len, | |
44353522 | 1149 | cache->addr_size, this_frame, cache->cfa, 1); |
4a4e5149 | 1150 | return frame_unwind_got_constant (this_frame, regnum, addr); |
46ea248b | 1151 | |
05cbe71a | 1152 | case DWARF2_FRAME_REG_UNSPECIFIED: |
3e2c4033 AC |
1153 | /* GCC, in its infinite wisdom decided to not provide unwind |
1154 | information for registers that are "same value". Since | |
1155 | DWARF2 (3 draft 7) doesn't define such behavior, said | |
1156 | registers are actually undefined (which is different to CFI | |
1157 | "undefined"). Code above issues a complaint about this. | |
1158 | Here just fudge the books, assume GCC, and that the value is | |
1159 | more inner on the stack. */ | |
4a4e5149 | 1160 | return frame_unwind_got_register (this_frame, regnum, regnum); |
3e2c4033 | 1161 | |
05cbe71a | 1162 | case DWARF2_FRAME_REG_SAME_VALUE: |
4a4e5149 | 1163 | return frame_unwind_got_register (this_frame, regnum, regnum); |
cfc14b3a | 1164 | |
05cbe71a | 1165 | case DWARF2_FRAME_REG_CFA: |
4a4e5149 | 1166 | return frame_unwind_got_address (this_frame, regnum, cache->cfa); |
35889917 | 1167 | |
ea7963f0 | 1168 | case DWARF2_FRAME_REG_CFA_OFFSET: |
4a4e5149 DJ |
1169 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1170 | return frame_unwind_got_address (this_frame, regnum, addr); | |
ea7963f0 | 1171 | |
8d5a9abc | 1172 | case DWARF2_FRAME_REG_RA_OFFSET: |
4a4e5149 DJ |
1173 | addr = cache->reg[regnum].loc.offset; |
1174 | regnum = gdbarch_dwarf2_reg_to_regnum | |
1175 | (gdbarch, cache->retaddr_reg.loc.reg); | |
1176 | addr += get_frame_register_unsigned (this_frame, regnum); | |
1177 | return frame_unwind_got_address (this_frame, regnum, addr); | |
8d5a9abc | 1178 | |
b39cc962 DJ |
1179 | case DWARF2_FRAME_REG_FN: |
1180 | return cache->reg[regnum].loc.fn (this_frame, this_cache, regnum); | |
1181 | ||
cfc14b3a | 1182 | default: |
e2e0b3e5 | 1183 | internal_error (__FILE__, __LINE__, _("Unknown register rule.")); |
cfc14b3a MK |
1184 | } |
1185 | } | |
1186 | ||
4a4e5149 DJ |
1187 | static int |
1188 | dwarf2_frame_sniffer (const struct frame_unwind *self, | |
1189 | struct frame_info *this_frame, void **this_cache) | |
cfc14b3a | 1190 | { |
1ce5d6dd | 1191 | /* Grab an address that is guarenteed to reside somewhere within the |
4a4e5149 | 1192 | function. get_frame_pc(), with a no-return next function, can |
93d42b30 DJ |
1193 | end up returning something past the end of this function's body. |
1194 | If the frame we're sniffing for is a signal frame whose start | |
1195 | address is placed on the stack by the OS, its FDE must | |
4a4e5149 DJ |
1196 | extend one byte before its start address or we could potentially |
1197 | select the FDE of the previous function. */ | |
1198 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); | |
56c987f6 | 1199 | struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr); |
9a619af0 | 1200 | |
56c987f6 | 1201 | if (!fde) |
4a4e5149 | 1202 | return 0; |
3ed09a32 DJ |
1203 | |
1204 | /* On some targets, signal trampolines may have unwind information. | |
1205 | We need to recognize them so that we set the frame type | |
1206 | correctly. */ | |
1207 | ||
56c987f6 | 1208 | if (fde->cie->signal_frame |
4a4e5149 DJ |
1209 | || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame), |
1210 | this_frame)) | |
1211 | return self->type == SIGTRAMP_FRAME; | |
1212 | ||
1213 | return self->type != SIGTRAMP_FRAME; | |
1214 | } | |
1215 | ||
1216 | static const struct frame_unwind dwarf2_frame_unwind = | |
1217 | { | |
1218 | NORMAL_FRAME, | |
1219 | dwarf2_frame_this_id, | |
1220 | dwarf2_frame_prev_register, | |
1221 | NULL, | |
1222 | dwarf2_frame_sniffer | |
1223 | }; | |
1224 | ||
1225 | static const struct frame_unwind dwarf2_signal_frame_unwind = | |
1226 | { | |
1227 | SIGTRAMP_FRAME, | |
1228 | dwarf2_frame_this_id, | |
1229 | dwarf2_frame_prev_register, | |
1230 | NULL, | |
1231 | dwarf2_frame_sniffer | |
1232 | }; | |
cfc14b3a | 1233 | |
4a4e5149 DJ |
1234 | /* Append the DWARF-2 frame unwinders to GDBARCH's list. */ |
1235 | ||
1236 | void | |
1237 | dwarf2_append_unwinders (struct gdbarch *gdbarch) | |
1238 | { | |
1239 | frame_unwind_append_unwinder (gdbarch, &dwarf2_frame_unwind); | |
1240 | frame_unwind_append_unwinder (gdbarch, &dwarf2_signal_frame_unwind); | |
cfc14b3a MK |
1241 | } |
1242 | \f | |
1243 | ||
1244 | /* There is no explicitly defined relationship between the CFA and the | |
1245 | location of frame's local variables and arguments/parameters. | |
1246 | Therefore, frame base methods on this page should probably only be | |
1247 | used as a last resort, just to avoid printing total garbage as a | |
1248 | response to the "info frame" command. */ | |
1249 | ||
1250 | static CORE_ADDR | |
4a4e5149 | 1251 | dwarf2_frame_base_address (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
1252 | { |
1253 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1254 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a MK |
1255 | |
1256 | return cache->cfa; | |
1257 | } | |
1258 | ||
1259 | static const struct frame_base dwarf2_frame_base = | |
1260 | { | |
1261 | &dwarf2_frame_unwind, | |
1262 | dwarf2_frame_base_address, | |
1263 | dwarf2_frame_base_address, | |
1264 | dwarf2_frame_base_address | |
1265 | }; | |
1266 | ||
1267 | const struct frame_base * | |
4a4e5149 | 1268 | dwarf2_frame_base_sniffer (struct frame_info *this_frame) |
cfc14b3a | 1269 | { |
4a4e5149 | 1270 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); |
9a619af0 | 1271 | |
93d42b30 | 1272 | if (dwarf2_frame_find_fde (&block_addr)) |
cfc14b3a MK |
1273 | return &dwarf2_frame_base; |
1274 | ||
1275 | return NULL; | |
1276 | } | |
e7802207 TT |
1277 | |
1278 | /* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from | |
1279 | the DWARF unwinder. This is used to implement | |
1280 | DW_OP_call_frame_cfa. */ | |
1281 | ||
1282 | CORE_ADDR | |
1283 | dwarf2_frame_cfa (struct frame_info *this_frame) | |
1284 | { | |
1285 | while (get_frame_type (this_frame) == INLINE_FRAME) | |
1286 | this_frame = get_prev_frame (this_frame); | |
1287 | /* This restriction could be lifted if other unwinders are known to | |
1288 | compute the frame base in a way compatible with the DWARF | |
1289 | unwinder. */ | |
1290 | if (! frame_unwinder_is (this_frame, &dwarf2_frame_unwind)) | |
1291 | error (_("can't compute CFA for this frame")); | |
1292 | return get_frame_base (this_frame); | |
1293 | } | |
cfc14b3a | 1294 | \f |
8f22cb90 | 1295 | const struct objfile_data *dwarf2_frame_objfile_data; |
0d0e1a63 | 1296 | |
cfc14b3a | 1297 | static unsigned int |
852483bc | 1298 | read_1_byte (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1299 | { |
852483bc | 1300 | return bfd_get_8 (abfd, buf); |
cfc14b3a MK |
1301 | } |
1302 | ||
1303 | static unsigned int | |
852483bc | 1304 | read_4_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1305 | { |
852483bc | 1306 | return bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1307 | } |
1308 | ||
1309 | static ULONGEST | |
852483bc | 1310 | read_8_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1311 | { |
852483bc | 1312 | return bfd_get_64 (abfd, buf); |
cfc14b3a MK |
1313 | } |
1314 | ||
1315 | static ULONGEST | |
852483bc | 1316 | read_unsigned_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1317 | { |
1318 | ULONGEST result; | |
1319 | unsigned int num_read; | |
1320 | int shift; | |
852483bc | 1321 | gdb_byte byte; |
cfc14b3a MK |
1322 | |
1323 | result = 0; | |
1324 | shift = 0; | |
1325 | num_read = 0; | |
1326 | ||
1327 | do | |
1328 | { | |
1329 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1330 | buf++; | |
1331 | num_read++; | |
1332 | result |= ((byte & 0x7f) << shift); | |
1333 | shift += 7; | |
1334 | } | |
1335 | while (byte & 0x80); | |
1336 | ||
1337 | *bytes_read_ptr = num_read; | |
1338 | ||
1339 | return result; | |
1340 | } | |
1341 | ||
1342 | static LONGEST | |
852483bc | 1343 | read_signed_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1344 | { |
1345 | LONGEST result; | |
1346 | int shift; | |
1347 | unsigned int num_read; | |
852483bc | 1348 | gdb_byte byte; |
cfc14b3a MK |
1349 | |
1350 | result = 0; | |
1351 | shift = 0; | |
1352 | num_read = 0; | |
1353 | ||
1354 | do | |
1355 | { | |
1356 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1357 | buf++; | |
1358 | num_read++; | |
1359 | result |= ((byte & 0x7f) << shift); | |
1360 | shift += 7; | |
1361 | } | |
1362 | while (byte & 0x80); | |
1363 | ||
77e0b926 DJ |
1364 | if (shift < 8 * sizeof (result) && (byte & 0x40)) |
1365 | result |= -(((LONGEST)1) << shift); | |
cfc14b3a MK |
1366 | |
1367 | *bytes_read_ptr = num_read; | |
1368 | ||
1369 | return result; | |
1370 | } | |
1371 | ||
1372 | static ULONGEST | |
852483bc | 1373 | read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1374 | { |
1375 | LONGEST result; | |
1376 | ||
852483bc | 1377 | result = bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1378 | if (result == 0xffffffff) |
1379 | { | |
852483bc | 1380 | result = bfd_get_64 (abfd, buf + 4); |
cfc14b3a MK |
1381 | *bytes_read_ptr = 12; |
1382 | } | |
1383 | else | |
1384 | *bytes_read_ptr = 4; | |
1385 | ||
1386 | return result; | |
1387 | } | |
1388 | \f | |
1389 | ||
1390 | /* Pointer encoding helper functions. */ | |
1391 | ||
1392 | /* GCC supports exception handling based on DWARF2 CFI. However, for | |
1393 | technical reasons, it encodes addresses in its FDE's in a different | |
1394 | way. Several "pointer encodings" are supported. The encoding | |
1395 | that's used for a particular FDE is determined by the 'R' | |
1396 | augmentation in the associated CIE. The argument of this | |
1397 | augmentation is a single byte. | |
1398 | ||
1399 | The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a | |
1400 | LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether | |
1401 | the address is signed or unsigned. Bits 4, 5 and 6 encode how the | |
1402 | address should be interpreted (absolute, relative to the current | |
1403 | position in the FDE, ...). Bit 7, indicates that the address | |
1404 | should be dereferenced. */ | |
1405 | ||
852483bc | 1406 | static gdb_byte |
cfc14b3a MK |
1407 | encoding_for_size (unsigned int size) |
1408 | { | |
1409 | switch (size) | |
1410 | { | |
1411 | case 2: | |
1412 | return DW_EH_PE_udata2; | |
1413 | case 4: | |
1414 | return DW_EH_PE_udata4; | |
1415 | case 8: | |
1416 | return DW_EH_PE_udata8; | |
1417 | default: | |
e2e0b3e5 | 1418 | internal_error (__FILE__, __LINE__, _("Unsupported address size")); |
cfc14b3a MK |
1419 | } |
1420 | } | |
1421 | ||
cfc14b3a | 1422 | static CORE_ADDR |
852483bc | 1423 | read_encoded_value (struct comp_unit *unit, gdb_byte encoding, |
0d45f56e TT |
1424 | int ptr_len, const gdb_byte *buf, |
1425 | unsigned int *bytes_read_ptr, | |
ae0d2f24 | 1426 | CORE_ADDR func_base) |
cfc14b3a | 1427 | { |
68f6cf99 | 1428 | ptrdiff_t offset; |
cfc14b3a MK |
1429 | CORE_ADDR base; |
1430 | ||
1431 | /* GCC currently doesn't generate DW_EH_PE_indirect encodings for | |
1432 | FDE's. */ | |
1433 | if (encoding & DW_EH_PE_indirect) | |
1434 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 1435 | _("Unsupported encoding: DW_EH_PE_indirect")); |
cfc14b3a | 1436 | |
68f6cf99 MK |
1437 | *bytes_read_ptr = 0; |
1438 | ||
cfc14b3a MK |
1439 | switch (encoding & 0x70) |
1440 | { | |
1441 | case DW_EH_PE_absptr: | |
1442 | base = 0; | |
1443 | break; | |
1444 | case DW_EH_PE_pcrel: | |
f2fec864 | 1445 | base = bfd_get_section_vma (unit->abfd, unit->dwarf_frame_section); |
852483bc | 1446 | base += (buf - unit->dwarf_frame_buffer); |
cfc14b3a | 1447 | break; |
0912c7f2 MK |
1448 | case DW_EH_PE_datarel: |
1449 | base = unit->dbase; | |
1450 | break; | |
0fd85043 CV |
1451 | case DW_EH_PE_textrel: |
1452 | base = unit->tbase; | |
1453 | break; | |
03ac2a74 | 1454 | case DW_EH_PE_funcrel: |
ae0d2f24 | 1455 | base = func_base; |
03ac2a74 | 1456 | break; |
68f6cf99 MK |
1457 | case DW_EH_PE_aligned: |
1458 | base = 0; | |
852483bc | 1459 | offset = buf - unit->dwarf_frame_buffer; |
68f6cf99 MK |
1460 | if ((offset % ptr_len) != 0) |
1461 | { | |
1462 | *bytes_read_ptr = ptr_len - (offset % ptr_len); | |
1463 | buf += *bytes_read_ptr; | |
1464 | } | |
1465 | break; | |
cfc14b3a | 1466 | default: |
e2e0b3e5 | 1467 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1468 | } |
1469 | ||
b04de778 | 1470 | if ((encoding & 0x07) == 0x00) |
f2fec864 DJ |
1471 | { |
1472 | encoding |= encoding_for_size (ptr_len); | |
1473 | if (bfd_get_sign_extend_vma (unit->abfd)) | |
1474 | encoding |= DW_EH_PE_signed; | |
1475 | } | |
cfc14b3a MK |
1476 | |
1477 | switch (encoding & 0x0f) | |
1478 | { | |
a81b10ae MK |
1479 | case DW_EH_PE_uleb128: |
1480 | { | |
1481 | ULONGEST value; | |
0d45f56e | 1482 | const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
9a619af0 | 1483 | |
a7289609 | 1484 | *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1485 | return base + value; |
1486 | } | |
cfc14b3a | 1487 | case DW_EH_PE_udata2: |
68f6cf99 | 1488 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1489 | return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf)); |
1490 | case DW_EH_PE_udata4: | |
68f6cf99 | 1491 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1492 | return (base + bfd_get_32 (unit->abfd, (bfd_byte *) buf)); |
1493 | case DW_EH_PE_udata8: | |
68f6cf99 | 1494 | *bytes_read_ptr += 8; |
cfc14b3a | 1495 | return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf)); |
a81b10ae MK |
1496 | case DW_EH_PE_sleb128: |
1497 | { | |
1498 | LONGEST value; | |
0d45f56e | 1499 | const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
9a619af0 | 1500 | |
a7289609 | 1501 | *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1502 | return base + value; |
1503 | } | |
cfc14b3a | 1504 | case DW_EH_PE_sdata2: |
68f6cf99 | 1505 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1506 | return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf)); |
1507 | case DW_EH_PE_sdata4: | |
68f6cf99 | 1508 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1509 | return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf)); |
1510 | case DW_EH_PE_sdata8: | |
68f6cf99 | 1511 | *bytes_read_ptr += 8; |
cfc14b3a MK |
1512 | return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf)); |
1513 | default: | |
e2e0b3e5 | 1514 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1515 | } |
1516 | } | |
1517 | \f | |
1518 | ||
b01c8410 PP |
1519 | static int |
1520 | bsearch_cie_cmp (const void *key, const void *element) | |
cfc14b3a | 1521 | { |
b01c8410 PP |
1522 | ULONGEST cie_pointer = *(ULONGEST *) key; |
1523 | struct dwarf2_cie *cie = *(struct dwarf2_cie **) element; | |
cfc14b3a | 1524 | |
b01c8410 PP |
1525 | if (cie_pointer == cie->cie_pointer) |
1526 | return 0; | |
cfc14b3a | 1527 | |
b01c8410 PP |
1528 | return (cie_pointer < cie->cie_pointer) ? -1 : 1; |
1529 | } | |
1530 | ||
1531 | /* Find CIE with the given CIE_POINTER in CIE_TABLE. */ | |
1532 | static struct dwarf2_cie * | |
1533 | find_cie (struct dwarf2_cie_table *cie_table, ULONGEST cie_pointer) | |
1534 | { | |
1535 | struct dwarf2_cie **p_cie; | |
cfc14b3a | 1536 | |
65a97ab3 PP |
1537 | /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to |
1538 | bsearch be non-NULL. */ | |
1539 | if (cie_table->entries == NULL) | |
1540 | { | |
1541 | gdb_assert (cie_table->num_entries == 0); | |
1542 | return NULL; | |
1543 | } | |
1544 | ||
b01c8410 PP |
1545 | p_cie = bsearch (&cie_pointer, cie_table->entries, cie_table->num_entries, |
1546 | sizeof (cie_table->entries[0]), bsearch_cie_cmp); | |
1547 | if (p_cie != NULL) | |
1548 | return *p_cie; | |
cfc14b3a MK |
1549 | return NULL; |
1550 | } | |
1551 | ||
b01c8410 | 1552 | /* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */ |
cfc14b3a | 1553 | static void |
b01c8410 | 1554 | add_cie (struct dwarf2_cie_table *cie_table, struct dwarf2_cie *cie) |
cfc14b3a | 1555 | { |
b01c8410 PP |
1556 | const int n = cie_table->num_entries; |
1557 | ||
1558 | gdb_assert (n < 1 | |
1559 | || cie_table->entries[n - 1]->cie_pointer < cie->cie_pointer); | |
1560 | ||
1561 | cie_table->entries = | |
1562 | xrealloc (cie_table->entries, (n + 1) * sizeof (cie_table->entries[0])); | |
1563 | cie_table->entries[n] = cie; | |
1564 | cie_table->num_entries = n + 1; | |
1565 | } | |
1566 | ||
1567 | static int | |
1568 | bsearch_fde_cmp (const void *key, const void *element) | |
1569 | { | |
1570 | CORE_ADDR seek_pc = *(CORE_ADDR *) key; | |
1571 | struct dwarf2_fde *fde = *(struct dwarf2_fde **) element; | |
9a619af0 | 1572 | |
b01c8410 PP |
1573 | if (seek_pc < fde->initial_location) |
1574 | return -1; | |
1575 | if (seek_pc < fde->initial_location + fde->address_range) | |
1576 | return 0; | |
1577 | return 1; | |
cfc14b3a MK |
1578 | } |
1579 | ||
1580 | /* Find the FDE for *PC. Return a pointer to the FDE, and store the | |
1581 | inital location associated with it into *PC. */ | |
1582 | ||
1583 | static struct dwarf2_fde * | |
1584 | dwarf2_frame_find_fde (CORE_ADDR *pc) | |
1585 | { | |
1586 | struct objfile *objfile; | |
1587 | ||
1588 | ALL_OBJFILES (objfile) | |
1589 | { | |
b01c8410 PP |
1590 | struct dwarf2_fde_table *fde_table; |
1591 | struct dwarf2_fde **p_fde; | |
cfc14b3a | 1592 | CORE_ADDR offset; |
b01c8410 | 1593 | CORE_ADDR seek_pc; |
cfc14b3a | 1594 | |
b01c8410 PP |
1595 | fde_table = objfile_data (objfile, dwarf2_frame_objfile_data); |
1596 | if (fde_table == NULL) | |
be391dca TT |
1597 | { |
1598 | dwarf2_build_frame_info (objfile); | |
1599 | fde_table = objfile_data (objfile, dwarf2_frame_objfile_data); | |
1600 | } | |
1601 | gdb_assert (fde_table != NULL); | |
1602 | ||
1603 | if (fde_table->num_entries == 0) | |
4ae9ee8e DJ |
1604 | continue; |
1605 | ||
1606 | gdb_assert (objfile->section_offsets); | |
1607 | offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile)); | |
1608 | ||
b01c8410 PP |
1609 | gdb_assert (fde_table->num_entries > 0); |
1610 | if (*pc < offset + fde_table->entries[0]->initial_location) | |
1611 | continue; | |
1612 | ||
1613 | seek_pc = *pc - offset; | |
1614 | p_fde = bsearch (&seek_pc, fde_table->entries, fde_table->num_entries, | |
1615 | sizeof (fde_table->entries[0]), bsearch_fde_cmp); | |
1616 | if (p_fde != NULL) | |
1617 | { | |
1618 | *pc = (*p_fde)->initial_location + offset; | |
1619 | return *p_fde; | |
1620 | } | |
cfc14b3a | 1621 | } |
cfc14b3a MK |
1622 | return NULL; |
1623 | } | |
1624 | ||
b01c8410 | 1625 | /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */ |
cfc14b3a | 1626 | static void |
b01c8410 | 1627 | add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde) |
cfc14b3a | 1628 | { |
b01c8410 PP |
1629 | if (fde->address_range == 0) |
1630 | /* Discard useless FDEs. */ | |
1631 | return; | |
1632 | ||
1633 | fde_table->num_entries += 1; | |
1634 | fde_table->entries = | |
1635 | xrealloc (fde_table->entries, | |
1636 | fde_table->num_entries * sizeof (fde_table->entries[0])); | |
1637 | fde_table->entries[fde_table->num_entries - 1] = fde; | |
cfc14b3a MK |
1638 | } |
1639 | ||
1640 | #ifdef CC_HAS_LONG_LONG | |
1641 | #define DW64_CIE_ID 0xffffffffffffffffULL | |
1642 | #else | |
1643 | #define DW64_CIE_ID ~0 | |
1644 | #endif | |
1645 | ||
852483bc | 1646 | static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start, |
b01c8410 PP |
1647 | int eh_frame_p, |
1648 | struct dwarf2_cie_table *cie_table, | |
1649 | struct dwarf2_fde_table *fde_table); | |
cfc14b3a | 1650 | |
6896c0c7 RH |
1651 | /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise |
1652 | the next byte to be processed. */ | |
852483bc | 1653 | static gdb_byte * |
b01c8410 PP |
1654 | decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1655 | struct dwarf2_cie_table *cie_table, | |
1656 | struct dwarf2_fde_table *fde_table) | |
cfc14b3a | 1657 | { |
5e2b427d | 1658 | struct gdbarch *gdbarch = get_objfile_arch (unit->objfile); |
852483bc | 1659 | gdb_byte *buf, *end; |
cfc14b3a MK |
1660 | LONGEST length; |
1661 | unsigned int bytes_read; | |
6896c0c7 RH |
1662 | int dwarf64_p; |
1663 | ULONGEST cie_id; | |
cfc14b3a | 1664 | ULONGEST cie_pointer; |
cfc14b3a | 1665 | |
6896c0c7 | 1666 | buf = start; |
cfc14b3a MK |
1667 | length = read_initial_length (unit->abfd, buf, &bytes_read); |
1668 | buf += bytes_read; | |
1669 | end = buf + length; | |
1670 | ||
6896c0c7 RH |
1671 | /* Are we still within the section? */ |
1672 | if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
1673 | return NULL; | |
1674 | ||
cfc14b3a MK |
1675 | if (length == 0) |
1676 | return end; | |
1677 | ||
6896c0c7 RH |
1678 | /* Distinguish between 32 and 64-bit encoded frame info. */ |
1679 | dwarf64_p = (bytes_read == 12); | |
cfc14b3a | 1680 | |
6896c0c7 | 1681 | /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */ |
cfc14b3a MK |
1682 | if (eh_frame_p) |
1683 | cie_id = 0; | |
1684 | else if (dwarf64_p) | |
1685 | cie_id = DW64_CIE_ID; | |
6896c0c7 RH |
1686 | else |
1687 | cie_id = DW_CIE_ID; | |
cfc14b3a MK |
1688 | |
1689 | if (dwarf64_p) | |
1690 | { | |
1691 | cie_pointer = read_8_bytes (unit->abfd, buf); | |
1692 | buf += 8; | |
1693 | } | |
1694 | else | |
1695 | { | |
1696 | cie_pointer = read_4_bytes (unit->abfd, buf); | |
1697 | buf += 4; | |
1698 | } | |
1699 | ||
1700 | if (cie_pointer == cie_id) | |
1701 | { | |
1702 | /* This is a CIE. */ | |
1703 | struct dwarf2_cie *cie; | |
1704 | char *augmentation; | |
28ba0b33 | 1705 | unsigned int cie_version; |
cfc14b3a MK |
1706 | |
1707 | /* Record the offset into the .debug_frame section of this CIE. */ | |
1708 | cie_pointer = start - unit->dwarf_frame_buffer; | |
1709 | ||
1710 | /* Check whether we've already read it. */ | |
b01c8410 | 1711 | if (find_cie (cie_table, cie_pointer)) |
cfc14b3a MK |
1712 | return end; |
1713 | ||
1714 | cie = (struct dwarf2_cie *) | |
8b92e4d5 | 1715 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a MK |
1716 | sizeof (struct dwarf2_cie)); |
1717 | cie->initial_instructions = NULL; | |
1718 | cie->cie_pointer = cie_pointer; | |
1719 | ||
1720 | /* The encoding for FDE's in a normal .debug_frame section | |
32b05c07 MK |
1721 | depends on the target address size. */ |
1722 | cie->encoding = DW_EH_PE_absptr; | |
cfc14b3a | 1723 | |
ae0d2f24 UW |
1724 | /* The target address size. For .eh_frame FDEs this is considered |
1725 | equal to the size of a target pointer. For .dwarf_frame FDEs, | |
1726 | this is supposed to be the target address size from the associated | |
1727 | CU header. FIXME: We do not have a good way to determine the | |
1728 | latter. Always use the target pointer size for now. */ | |
5e2b427d | 1729 | cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
ae0d2f24 | 1730 | |
56c987f6 AO |
1731 | /* We'll determine the final value later, but we need to |
1732 | initialize it conservatively. */ | |
1733 | cie->signal_frame = 0; | |
1734 | ||
cfc14b3a | 1735 | /* Check version number. */ |
28ba0b33 | 1736 | cie_version = read_1_byte (unit->abfd, buf); |
2dc7f7b3 | 1737 | if (cie_version != 1 && cie_version != 3 && cie_version != 4) |
6896c0c7 | 1738 | return NULL; |
303b6f5d | 1739 | cie->version = cie_version; |
cfc14b3a MK |
1740 | buf += 1; |
1741 | ||
1742 | /* Interpret the interesting bits of the augmentation. */ | |
303b6f5d | 1743 | cie->augmentation = augmentation = (char *) buf; |
852483bc | 1744 | buf += (strlen (augmentation) + 1); |
cfc14b3a | 1745 | |
303b6f5d DJ |
1746 | /* Ignore armcc augmentations. We only use them for quirks, |
1747 | and that doesn't happen until later. */ | |
1748 | if (strncmp (augmentation, "armcc", 5) == 0) | |
1749 | augmentation += strlen (augmentation); | |
1750 | ||
cfc14b3a MK |
1751 | /* The GCC 2.x "eh" augmentation has a pointer immediately |
1752 | following the augmentation string, so it must be handled | |
1753 | first. */ | |
1754 | if (augmentation[0] == 'e' && augmentation[1] == 'h') | |
1755 | { | |
1756 | /* Skip. */ | |
5e2b427d | 1757 | buf += gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
cfc14b3a MK |
1758 | augmentation += 2; |
1759 | } | |
1760 | ||
2dc7f7b3 TT |
1761 | if (cie->version >= 4) |
1762 | { | |
1763 | /* FIXME: check that this is the same as from the CU header. */ | |
1764 | cie->addr_size = read_1_byte (unit->abfd, buf); | |
1765 | ++buf; | |
1766 | cie->segment_size = read_1_byte (unit->abfd, buf); | |
1767 | ++buf; | |
1768 | } | |
1769 | else | |
1770 | { | |
1771 | cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; | |
1772 | cie->segment_size = 0; | |
1773 | } | |
1774 | ||
cfc14b3a MK |
1775 | cie->code_alignment_factor = |
1776 | read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1777 | buf += bytes_read; | |
1778 | ||
1779 | cie->data_alignment_factor = | |
1780 | read_signed_leb128 (unit->abfd, buf, &bytes_read); | |
1781 | buf += bytes_read; | |
1782 | ||
28ba0b33 PB |
1783 | if (cie_version == 1) |
1784 | { | |
1785 | cie->return_address_register = read_1_byte (unit->abfd, buf); | |
1786 | bytes_read = 1; | |
1787 | } | |
1788 | else | |
1789 | cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf, | |
1790 | &bytes_read); | |
4fc771b8 | 1791 | cie->return_address_register |
5e2b427d | 1792 | = dwarf2_frame_adjust_regnum (gdbarch, |
4fc771b8 DJ |
1793 | cie->return_address_register, |
1794 | eh_frame_p); | |
4bf8967c | 1795 | |
28ba0b33 | 1796 | buf += bytes_read; |
cfc14b3a | 1797 | |
7131cb6e RH |
1798 | cie->saw_z_augmentation = (*augmentation == 'z'); |
1799 | if (cie->saw_z_augmentation) | |
cfc14b3a MK |
1800 | { |
1801 | ULONGEST length; | |
1802 | ||
1803 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1804 | buf += bytes_read; | |
6896c0c7 RH |
1805 | if (buf > end) |
1806 | return NULL; | |
cfc14b3a MK |
1807 | cie->initial_instructions = buf + length; |
1808 | augmentation++; | |
1809 | } | |
1810 | ||
1811 | while (*augmentation) | |
1812 | { | |
1813 | /* "L" indicates a byte showing how the LSDA pointer is encoded. */ | |
1814 | if (*augmentation == 'L') | |
1815 | { | |
1816 | /* Skip. */ | |
1817 | buf++; | |
1818 | augmentation++; | |
1819 | } | |
1820 | ||
1821 | /* "R" indicates a byte indicating how FDE addresses are encoded. */ | |
1822 | else if (*augmentation == 'R') | |
1823 | { | |
1824 | cie->encoding = *buf++; | |
1825 | augmentation++; | |
1826 | } | |
1827 | ||
1828 | /* "P" indicates a personality routine in the CIE augmentation. */ | |
1829 | else if (*augmentation == 'P') | |
1830 | { | |
1234d960 | 1831 | /* Skip. Avoid indirection since we throw away the result. */ |
852483bc | 1832 | gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect; |
ae0d2f24 UW |
1833 | read_encoded_value (unit, encoding, cie->addr_size, |
1834 | buf, &bytes_read, 0); | |
f724bf08 | 1835 | buf += bytes_read; |
cfc14b3a MK |
1836 | augmentation++; |
1837 | } | |
1838 | ||
56c987f6 AO |
1839 | /* "S" indicates a signal frame, such that the return |
1840 | address must not be decremented to locate the call frame | |
1841 | info for the previous frame; it might even be the first | |
1842 | instruction of a function, so decrementing it would take | |
1843 | us to a different function. */ | |
1844 | else if (*augmentation == 'S') | |
1845 | { | |
1846 | cie->signal_frame = 1; | |
1847 | augmentation++; | |
1848 | } | |
1849 | ||
3e9a2e52 DJ |
1850 | /* Otherwise we have an unknown augmentation. Assume that either |
1851 | there is no augmentation data, or we saw a 'z' prefix. */ | |
cfc14b3a MK |
1852 | else |
1853 | { | |
3e9a2e52 DJ |
1854 | if (cie->initial_instructions) |
1855 | buf = cie->initial_instructions; | |
cfc14b3a MK |
1856 | break; |
1857 | } | |
1858 | } | |
1859 | ||
1860 | cie->initial_instructions = buf; | |
1861 | cie->end = end; | |
b01c8410 | 1862 | cie->unit = unit; |
cfc14b3a | 1863 | |
b01c8410 | 1864 | add_cie (cie_table, cie); |
cfc14b3a MK |
1865 | } |
1866 | else | |
1867 | { | |
1868 | /* This is a FDE. */ | |
1869 | struct dwarf2_fde *fde; | |
1870 | ||
6896c0c7 RH |
1871 | /* In an .eh_frame section, the CIE pointer is the delta between the |
1872 | address within the FDE where the CIE pointer is stored and the | |
1873 | address of the CIE. Convert it to an offset into the .eh_frame | |
1874 | section. */ | |
cfc14b3a MK |
1875 | if (eh_frame_p) |
1876 | { | |
cfc14b3a MK |
1877 | cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer; |
1878 | cie_pointer -= (dwarf64_p ? 8 : 4); | |
1879 | } | |
1880 | ||
6896c0c7 RH |
1881 | /* In either case, validate the result is still within the section. */ |
1882 | if (cie_pointer >= unit->dwarf_frame_size) | |
1883 | return NULL; | |
1884 | ||
cfc14b3a | 1885 | fde = (struct dwarf2_fde *) |
8b92e4d5 | 1886 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a | 1887 | sizeof (struct dwarf2_fde)); |
b01c8410 | 1888 | fde->cie = find_cie (cie_table, cie_pointer); |
cfc14b3a MK |
1889 | if (fde->cie == NULL) |
1890 | { | |
1891 | decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer, | |
b01c8410 PP |
1892 | eh_frame_p, cie_table, fde_table); |
1893 | fde->cie = find_cie (cie_table, cie_pointer); | |
cfc14b3a MK |
1894 | } |
1895 | ||
1896 | gdb_assert (fde->cie != NULL); | |
1897 | ||
1898 | fde->initial_location = | |
ae0d2f24 UW |
1899 | read_encoded_value (unit, fde->cie->encoding, fde->cie->addr_size, |
1900 | buf, &bytes_read, 0); | |
cfc14b3a MK |
1901 | buf += bytes_read; |
1902 | ||
1903 | fde->address_range = | |
ae0d2f24 UW |
1904 | read_encoded_value (unit, fde->cie->encoding & 0x0f, |
1905 | fde->cie->addr_size, buf, &bytes_read, 0); | |
cfc14b3a MK |
1906 | buf += bytes_read; |
1907 | ||
7131cb6e RH |
1908 | /* A 'z' augmentation in the CIE implies the presence of an |
1909 | augmentation field in the FDE as well. The only thing known | |
1910 | to be in here at present is the LSDA entry for EH. So we | |
1911 | can skip the whole thing. */ | |
1912 | if (fde->cie->saw_z_augmentation) | |
1913 | { | |
1914 | ULONGEST length; | |
1915 | ||
1916 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1917 | buf += bytes_read + length; | |
6896c0c7 RH |
1918 | if (buf > end) |
1919 | return NULL; | |
7131cb6e RH |
1920 | } |
1921 | ||
cfc14b3a MK |
1922 | fde->instructions = buf; |
1923 | fde->end = end; | |
1924 | ||
4bf8967c AS |
1925 | fde->eh_frame_p = eh_frame_p; |
1926 | ||
b01c8410 | 1927 | add_fde (fde_table, fde); |
cfc14b3a MK |
1928 | } |
1929 | ||
1930 | return end; | |
1931 | } | |
6896c0c7 RH |
1932 | |
1933 | /* Read a CIE or FDE in BUF and decode it. */ | |
852483bc | 1934 | static gdb_byte * |
b01c8410 PP |
1935 | decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1936 | struct dwarf2_cie_table *cie_table, | |
1937 | struct dwarf2_fde_table *fde_table) | |
6896c0c7 RH |
1938 | { |
1939 | enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE; | |
852483bc | 1940 | gdb_byte *ret; |
6896c0c7 RH |
1941 | ptrdiff_t start_offset; |
1942 | ||
1943 | while (1) | |
1944 | { | |
b01c8410 PP |
1945 | ret = decode_frame_entry_1 (unit, start, eh_frame_p, |
1946 | cie_table, fde_table); | |
6896c0c7 RH |
1947 | if (ret != NULL) |
1948 | break; | |
1949 | ||
1950 | /* We have corrupt input data of some form. */ | |
1951 | ||
1952 | /* ??? Try, weakly, to work around compiler/assembler/linker bugs | |
1953 | and mismatches wrt padding and alignment of debug sections. */ | |
1954 | /* Note that there is no requirement in the standard for any | |
1955 | alignment at all in the frame unwind sections. Testing for | |
1956 | alignment before trying to interpret data would be incorrect. | |
1957 | ||
1958 | However, GCC traditionally arranged for frame sections to be | |
1959 | sized such that the FDE length and CIE fields happen to be | |
1960 | aligned (in theory, for performance). This, unfortunately, | |
1961 | was done with .align directives, which had the side effect of | |
1962 | forcing the section to be aligned by the linker. | |
1963 | ||
1964 | This becomes a problem when you have some other producer that | |
1965 | creates frame sections that are not as strictly aligned. That | |
1966 | produces a hole in the frame info that gets filled by the | |
1967 | linker with zeros. | |
1968 | ||
1969 | The GCC behaviour is arguably a bug, but it's effectively now | |
1970 | part of the ABI, so we're now stuck with it, at least at the | |
1971 | object file level. A smart linker may decide, in the process | |
1972 | of compressing duplicate CIE information, that it can rewrite | |
1973 | the entire output section without this extra padding. */ | |
1974 | ||
1975 | start_offset = start - unit->dwarf_frame_buffer; | |
1976 | if (workaround < ALIGN4 && (start_offset & 3) != 0) | |
1977 | { | |
1978 | start += 4 - (start_offset & 3); | |
1979 | workaround = ALIGN4; | |
1980 | continue; | |
1981 | } | |
1982 | if (workaround < ALIGN8 && (start_offset & 7) != 0) | |
1983 | { | |
1984 | start += 8 - (start_offset & 7); | |
1985 | workaround = ALIGN8; | |
1986 | continue; | |
1987 | } | |
1988 | ||
1989 | /* Nothing left to try. Arrange to return as if we've consumed | |
1990 | the entire input section. Hopefully we'll get valid info from | |
1991 | the other of .debug_frame/.eh_frame. */ | |
1992 | workaround = FAIL; | |
1993 | ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size; | |
1994 | break; | |
1995 | } | |
1996 | ||
1997 | switch (workaround) | |
1998 | { | |
1999 | case NONE: | |
2000 | break; | |
2001 | ||
2002 | case ALIGN4: | |
2003 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2004 | _("Corrupt data in %s:%s; align 4 workaround apparently succeeded"), |
6896c0c7 RH |
2005 | unit->dwarf_frame_section->owner->filename, |
2006 | unit->dwarf_frame_section->name); | |
2007 | break; | |
2008 | ||
2009 | case ALIGN8: | |
2010 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2011 | _("Corrupt data in %s:%s; align 8 workaround apparently succeeded"), |
6896c0c7 RH |
2012 | unit->dwarf_frame_section->owner->filename, |
2013 | unit->dwarf_frame_section->name); | |
2014 | break; | |
2015 | ||
2016 | default: | |
2017 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2018 | _("Corrupt data in %s:%s"), |
6896c0c7 RH |
2019 | unit->dwarf_frame_section->owner->filename, |
2020 | unit->dwarf_frame_section->name); | |
2021 | break; | |
2022 | } | |
2023 | ||
2024 | return ret; | |
2025 | } | |
cfc14b3a MK |
2026 | \f |
2027 | ||
cfc14b3a | 2028 | /* Imported from dwarf2read.c. */ |
dce234bc PP |
2029 | extern void dwarf2_get_section_info (struct objfile *, const char *, asection **, |
2030 | gdb_byte **, bfd_size_type *); | |
cfc14b3a | 2031 | |
b01c8410 PP |
2032 | static int |
2033 | qsort_fde_cmp (const void *a, const void *b) | |
2034 | { | |
2035 | struct dwarf2_fde *aa = *(struct dwarf2_fde **)a; | |
2036 | struct dwarf2_fde *bb = *(struct dwarf2_fde **)b; | |
e5af178f | 2037 | |
b01c8410 | 2038 | if (aa->initial_location == bb->initial_location) |
e5af178f PP |
2039 | { |
2040 | if (aa->address_range != bb->address_range | |
2041 | && aa->eh_frame_p == 0 && bb->eh_frame_p == 0) | |
2042 | /* Linker bug, e.g. gold/10400. | |
2043 | Work around it by keeping stable sort order. */ | |
2044 | return (a < b) ? -1 : 1; | |
2045 | else | |
2046 | /* Put eh_frame entries after debug_frame ones. */ | |
2047 | return aa->eh_frame_p - bb->eh_frame_p; | |
2048 | } | |
b01c8410 PP |
2049 | |
2050 | return (aa->initial_location < bb->initial_location) ? -1 : 1; | |
2051 | } | |
2052 | ||
cfc14b3a MK |
2053 | void |
2054 | dwarf2_build_frame_info (struct objfile *objfile) | |
2055 | { | |
ae0d2f24 | 2056 | struct comp_unit *unit; |
852483bc | 2057 | gdb_byte *frame_ptr; |
b01c8410 PP |
2058 | struct dwarf2_cie_table cie_table; |
2059 | struct dwarf2_fde_table fde_table; | |
be391dca | 2060 | struct dwarf2_fde_table *fde_table2; |
b01c8410 PP |
2061 | |
2062 | cie_table.num_entries = 0; | |
2063 | cie_table.entries = NULL; | |
2064 | ||
2065 | fde_table.num_entries = 0; | |
2066 | fde_table.entries = NULL; | |
cfc14b3a MK |
2067 | |
2068 | /* Build a minimal decoding of the DWARF2 compilation unit. */ | |
ae0d2f24 UW |
2069 | unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack, |
2070 | sizeof (struct comp_unit)); | |
2071 | unit->abfd = objfile->obfd; | |
2072 | unit->objfile = objfile; | |
2073 | unit->dbase = 0; | |
2074 | unit->tbase = 0; | |
cfc14b3a | 2075 | |
dce234bc PP |
2076 | dwarf2_get_section_info (objfile, ".eh_frame", |
2077 | &unit->dwarf_frame_section, | |
2078 | &unit->dwarf_frame_buffer, | |
2079 | &unit->dwarf_frame_size); | |
2080 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2081 | { |
0fd85043 | 2082 | asection *got, *txt; |
0912c7f2 | 2083 | |
0912c7f2 | 2084 | /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base |
37b517aa MK |
2085 | that is used for the i386/amd64 target, which currently is |
2086 | the only target in GCC that supports/uses the | |
2087 | DW_EH_PE_datarel encoding. */ | |
ae0d2f24 | 2088 | got = bfd_get_section_by_name (unit->abfd, ".got"); |
0912c7f2 | 2089 | if (got) |
ae0d2f24 | 2090 | unit->dbase = got->vma; |
0912c7f2 | 2091 | |
22c7ba1a MK |
2092 | /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64 |
2093 | so far. */ | |
ae0d2f24 | 2094 | txt = bfd_get_section_by_name (unit->abfd, ".text"); |
0fd85043 | 2095 | if (txt) |
ae0d2f24 | 2096 | unit->tbase = txt->vma; |
0fd85043 | 2097 | |
ae0d2f24 UW |
2098 | frame_ptr = unit->dwarf_frame_buffer; |
2099 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2100 | frame_ptr = decode_frame_entry (unit, frame_ptr, 1, |
2101 | &cie_table, &fde_table); | |
2102 | ||
2103 | if (cie_table.num_entries != 0) | |
2104 | { | |
2105 | /* Reinit cie_table: debug_frame has different CIEs. */ | |
2106 | xfree (cie_table.entries); | |
2107 | cie_table.num_entries = 0; | |
2108 | cie_table.entries = NULL; | |
2109 | } | |
cfc14b3a MK |
2110 | } |
2111 | ||
dce234bc PP |
2112 | dwarf2_get_section_info (objfile, ".debug_frame", |
2113 | &unit->dwarf_frame_section, | |
2114 | &unit->dwarf_frame_buffer, | |
2115 | &unit->dwarf_frame_size); | |
2116 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2117 | { |
ae0d2f24 UW |
2118 | frame_ptr = unit->dwarf_frame_buffer; |
2119 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2120 | frame_ptr = decode_frame_entry (unit, frame_ptr, 0, |
2121 | &cie_table, &fde_table); | |
2122 | } | |
2123 | ||
2124 | /* Discard the cie_table, it is no longer needed. */ | |
2125 | if (cie_table.num_entries != 0) | |
2126 | { | |
2127 | xfree (cie_table.entries); | |
2128 | cie_table.entries = NULL; /* Paranoia. */ | |
2129 | cie_table.num_entries = 0; /* Paranoia. */ | |
2130 | } | |
2131 | ||
be391dca TT |
2132 | /* Copy fde_table to obstack: it is needed at runtime. */ |
2133 | fde_table2 = (struct dwarf2_fde_table *) | |
2134 | obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2)); | |
2135 | ||
2136 | if (fde_table.num_entries == 0) | |
2137 | { | |
2138 | fde_table2->entries = NULL; | |
2139 | fde_table2->num_entries = 0; | |
2140 | } | |
2141 | else | |
b01c8410 | 2142 | { |
875cdfbb PA |
2143 | struct dwarf2_fde *fde_prev = NULL; |
2144 | struct dwarf2_fde *first_non_zero_fde = NULL; | |
2145 | int i; | |
b01c8410 PP |
2146 | |
2147 | /* Prepare FDE table for lookups. */ | |
2148 | qsort (fde_table.entries, fde_table.num_entries, | |
2149 | sizeof (fde_table.entries[0]), qsort_fde_cmp); | |
2150 | ||
875cdfbb PA |
2151 | /* Check for leftovers from --gc-sections. The GNU linker sets |
2152 | the relevant symbols to zero, but doesn't zero the FDE *end* | |
2153 | ranges because there's no relocation there. It's (offset, | |
2154 | length), not (start, end). On targets where address zero is | |
2155 | just another valid address this can be a problem, since the | |
2156 | FDEs appear to be non-empty in the output --- we could pick | |
2157 | out the wrong FDE. To work around this, when overlaps are | |
2158 | detected, we prefer FDEs that do not start at zero. | |
2159 | ||
2160 | Start by finding the first FDE with non-zero start. Below | |
2161 | we'll discard all FDEs that start at zero and overlap this | |
2162 | one. */ | |
2163 | for (i = 0; i < fde_table.num_entries; i++) | |
2164 | { | |
2165 | struct dwarf2_fde *fde = fde_table.entries[i]; | |
b01c8410 | 2166 | |
875cdfbb PA |
2167 | if (fde->initial_location != 0) |
2168 | { | |
2169 | first_non_zero_fde = fde; | |
2170 | break; | |
2171 | } | |
2172 | } | |
2173 | ||
2174 | /* Since we'll be doing bsearch, squeeze out identical (except | |
2175 | for eh_frame_p) fde entries so bsearch result is predictable. | |
2176 | Also discard leftovers from --gc-sections. */ | |
be391dca | 2177 | fde_table2->num_entries = 0; |
875cdfbb PA |
2178 | for (i = 0; i < fde_table.num_entries; i++) |
2179 | { | |
2180 | struct dwarf2_fde *fde = fde_table.entries[i]; | |
2181 | ||
2182 | if (fde->initial_location == 0 | |
2183 | && first_non_zero_fde != NULL | |
2184 | && (first_non_zero_fde->initial_location | |
2185 | < fde->initial_location + fde->address_range)) | |
2186 | continue; | |
2187 | ||
2188 | if (fde_prev != NULL | |
2189 | && fde_prev->initial_location == fde->initial_location) | |
2190 | continue; | |
2191 | ||
2192 | obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i], | |
2193 | sizeof (fde_table.entries[0])); | |
2194 | ++fde_table2->num_entries; | |
2195 | fde_prev = fde; | |
2196 | } | |
b01c8410 | 2197 | fde_table2->entries = obstack_finish (&objfile->objfile_obstack); |
b01c8410 PP |
2198 | |
2199 | /* Discard the original fde_table. */ | |
2200 | xfree (fde_table.entries); | |
cfc14b3a | 2201 | } |
be391dca TT |
2202 | |
2203 | set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2); | |
cfc14b3a | 2204 | } |
0d0e1a63 MK |
2205 | |
2206 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
2207 | void _initialize_dwarf2_frame (void); | |
2208 | ||
2209 | void | |
2210 | _initialize_dwarf2_frame (void) | |
2211 | { | |
030f20e1 | 2212 | dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init); |
8f22cb90 | 2213 | dwarf2_frame_objfile_data = register_objfile_data (); |
0d0e1a63 | 2214 | } |