Commit | Line | Data |
---|---|---|
cfc14b3a MK |
1 | /* Frame unwinder for frames with DWARF Call Frame Information. |
2 | ||
0fb0cc75 JB |
3 | Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009 |
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; | |
b01c8410 | 88 | }; |
303b6f5d | 89 | |
b01c8410 PP |
90 | struct dwarf2_cie_table |
91 | { | |
92 | int num_entries; | |
93 | struct dwarf2_cie **entries; | |
cfc14b3a MK |
94 | }; |
95 | ||
96 | /* Frame Description Entry (FDE). */ | |
97 | ||
98 | struct dwarf2_fde | |
99 | { | |
100 | /* CIE for this FDE. */ | |
101 | struct dwarf2_cie *cie; | |
102 | ||
103 | /* First location associated with this FDE. */ | |
104 | CORE_ADDR initial_location; | |
105 | ||
106 | /* Number of bytes of program instructions described by this FDE. */ | |
107 | CORE_ADDR address_range; | |
108 | ||
109 | /* Instruction sequence. */ | |
852483bc MK |
110 | gdb_byte *instructions; |
111 | gdb_byte *end; | |
cfc14b3a | 112 | |
4bf8967c AS |
113 | /* True if this FDE is read from a .eh_frame instead of a .debug_frame |
114 | section. */ | |
115 | unsigned char eh_frame_p; | |
b01c8410 | 116 | }; |
4bf8967c | 117 | |
b01c8410 PP |
118 | struct dwarf2_fde_table |
119 | { | |
120 | int num_entries; | |
121 | struct dwarf2_fde **entries; | |
cfc14b3a MK |
122 | }; |
123 | ||
ae0d2f24 UW |
124 | /* A minimal decoding of DWARF2 compilation units. We only decode |
125 | what's needed to get to the call frame information. */ | |
126 | ||
127 | struct comp_unit | |
128 | { | |
129 | /* Keep the bfd convenient. */ | |
130 | bfd *abfd; | |
131 | ||
132 | struct objfile *objfile; | |
133 | ||
ae0d2f24 UW |
134 | /* Pointer to the .debug_frame section loaded into memory. */ |
135 | gdb_byte *dwarf_frame_buffer; | |
136 | ||
137 | /* Length of the loaded .debug_frame section. */ | |
c098b58b | 138 | bfd_size_type dwarf_frame_size; |
ae0d2f24 UW |
139 | |
140 | /* Pointer to the .debug_frame section. */ | |
141 | asection *dwarf_frame_section; | |
142 | ||
143 | /* Base for DW_EH_PE_datarel encodings. */ | |
144 | bfd_vma dbase; | |
145 | ||
146 | /* Base for DW_EH_PE_textrel encodings. */ | |
147 | bfd_vma tbase; | |
148 | }; | |
149 | ||
cfc14b3a | 150 | static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc); |
4fc771b8 DJ |
151 | |
152 | static int dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, | |
153 | int eh_frame_p); | |
ae0d2f24 UW |
154 | |
155 | static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding, | |
156 | int ptr_len, gdb_byte *buf, | |
157 | unsigned int *bytes_read_ptr, | |
158 | CORE_ADDR func_base); | |
cfc14b3a MK |
159 | \f |
160 | ||
161 | /* Structure describing a frame state. */ | |
162 | ||
163 | struct dwarf2_frame_state | |
164 | { | |
165 | /* Each register save state can be described in terms of a CFA slot, | |
166 | another register, or a location expression. */ | |
167 | struct dwarf2_frame_state_reg_info | |
168 | { | |
05cbe71a | 169 | struct dwarf2_frame_state_reg *reg; |
cfc14b3a MK |
170 | int num_regs; |
171 | ||
2fd481e1 PP |
172 | LONGEST cfa_offset; |
173 | ULONGEST cfa_reg; | |
174 | enum { | |
175 | CFA_UNSET, | |
176 | CFA_REG_OFFSET, | |
177 | CFA_EXP | |
178 | } cfa_how; | |
179 | gdb_byte *cfa_exp; | |
180 | ||
cfc14b3a MK |
181 | /* Used to implement DW_CFA_remember_state. */ |
182 | struct dwarf2_frame_state_reg_info *prev; | |
183 | } regs; | |
184 | ||
cfc14b3a MK |
185 | /* The PC described by the current frame state. */ |
186 | CORE_ADDR pc; | |
187 | ||
188 | /* Initial register set from the CIE. | |
189 | Used to implement DW_CFA_restore. */ | |
190 | struct dwarf2_frame_state_reg_info initial; | |
191 | ||
192 | /* The information we care about from the CIE. */ | |
193 | LONGEST data_align; | |
194 | ULONGEST code_align; | |
195 | ULONGEST retaddr_column; | |
303b6f5d DJ |
196 | |
197 | /* Flags for known producer quirks. */ | |
198 | ||
199 | /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa | |
200 | and DW_CFA_def_cfa_offset takes a factored offset. */ | |
201 | int armcc_cfa_offsets_sf; | |
202 | ||
203 | /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that | |
204 | the CFA is defined as REG - OFFSET rather than REG + OFFSET. */ | |
205 | int armcc_cfa_offsets_reversed; | |
cfc14b3a MK |
206 | }; |
207 | ||
208 | /* Store the length the expression for the CFA in the `cfa_reg' field, | |
209 | which is unused in that case. */ | |
210 | #define cfa_exp_len cfa_reg | |
211 | ||
f57d151a | 212 | /* Assert that the register set RS is large enough to store gdbarch_num_regs |
cfc14b3a MK |
213 | columns. If necessary, enlarge the register set. */ |
214 | ||
215 | static void | |
216 | dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs, | |
217 | int num_regs) | |
218 | { | |
219 | size_t size = sizeof (struct dwarf2_frame_state_reg); | |
220 | ||
221 | if (num_regs <= rs->num_regs) | |
222 | return; | |
223 | ||
224 | rs->reg = (struct dwarf2_frame_state_reg *) | |
225 | xrealloc (rs->reg, num_regs * size); | |
226 | ||
227 | /* Initialize newly allocated registers. */ | |
2473a4a9 | 228 | memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size); |
cfc14b3a MK |
229 | rs->num_regs = num_regs; |
230 | } | |
231 | ||
232 | /* Copy the register columns in register set RS into newly allocated | |
233 | memory and return a pointer to this newly created copy. */ | |
234 | ||
235 | static struct dwarf2_frame_state_reg * | |
236 | dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs) | |
237 | { | |
d10891d4 | 238 | size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg); |
cfc14b3a MK |
239 | struct dwarf2_frame_state_reg *reg; |
240 | ||
241 | reg = (struct dwarf2_frame_state_reg *) xmalloc (size); | |
242 | memcpy (reg, rs->reg, size); | |
243 | ||
244 | return reg; | |
245 | } | |
246 | ||
247 | /* Release the memory allocated to register set RS. */ | |
248 | ||
249 | static void | |
250 | dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs) | |
251 | { | |
252 | if (rs) | |
253 | { | |
254 | dwarf2_frame_state_free_regs (rs->prev); | |
255 | ||
256 | xfree (rs->reg); | |
257 | xfree (rs); | |
258 | } | |
259 | } | |
260 | ||
261 | /* Release the memory allocated to the frame state FS. */ | |
262 | ||
263 | static void | |
264 | dwarf2_frame_state_free (void *p) | |
265 | { | |
266 | struct dwarf2_frame_state *fs = p; | |
267 | ||
268 | dwarf2_frame_state_free_regs (fs->initial.prev); | |
269 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
270 | xfree (fs->initial.reg); | |
271 | xfree (fs->regs.reg); | |
272 | xfree (fs); | |
273 | } | |
274 | \f | |
275 | ||
276 | /* Helper functions for execute_stack_op. */ | |
277 | ||
278 | static CORE_ADDR | |
279 | read_reg (void *baton, int reg) | |
280 | { | |
4a4e5149 DJ |
281 | struct frame_info *this_frame = (struct frame_info *) baton; |
282 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
cfc14b3a | 283 | int regnum; |
852483bc | 284 | gdb_byte *buf; |
cfc14b3a | 285 | |
ad010def | 286 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); |
cfc14b3a | 287 | |
852483bc | 288 | buf = alloca (register_size (gdbarch, regnum)); |
4a4e5149 | 289 | get_frame_register (this_frame, regnum, buf); |
f2da6b3a DJ |
290 | |
291 | /* Convert the register to an integer. This returns a LONGEST | |
292 | rather than a CORE_ADDR, but unpack_pointer does the same thing | |
293 | under the covers, and this makes more sense for non-pointer | |
294 | registers. Maybe read_reg and the associated interfaces should | |
295 | deal with "struct value" instead of CORE_ADDR. */ | |
296 | return unpack_long (register_type (gdbarch, regnum), buf); | |
cfc14b3a MK |
297 | } |
298 | ||
299 | static void | |
852483bc | 300 | read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
cfc14b3a MK |
301 | { |
302 | read_memory (addr, buf, len); | |
303 | } | |
304 | ||
305 | static void | |
852483bc | 306 | no_get_frame_base (void *baton, gdb_byte **start, size_t *length) |
cfc14b3a MK |
307 | { |
308 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 309 | _("Support for DW_OP_fbreg is unimplemented")); |
cfc14b3a MK |
310 | } |
311 | ||
e7802207 TT |
312 | /* Helper function for execute_stack_op. */ |
313 | ||
314 | static CORE_ADDR | |
315 | no_get_frame_cfa (void *baton) | |
316 | { | |
317 | internal_error (__FILE__, __LINE__, | |
318 | _("Support for DW_OP_call_frame_cfa is unimplemented")); | |
319 | } | |
320 | ||
cfc14b3a MK |
321 | static CORE_ADDR |
322 | no_get_tls_address (void *baton, CORE_ADDR offset) | |
323 | { | |
324 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 325 | _("Support for DW_OP_GNU_push_tls_address is unimplemented")); |
cfc14b3a MK |
326 | } |
327 | ||
a6a5a945 LM |
328 | /* Execute the required actions for both the DW_CFA_restore and |
329 | DW_CFA_restore_extended instructions. */ | |
330 | static void | |
331 | dwarf2_restore_rule (struct gdbarch *gdbarch, ULONGEST reg_num, | |
332 | struct dwarf2_frame_state *fs, int eh_frame_p) | |
333 | { | |
334 | ULONGEST reg; | |
335 | ||
336 | gdb_assert (fs->initial.reg); | |
337 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg_num, eh_frame_p); | |
338 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
339 | ||
340 | /* Check if this register was explicitly initialized in the | |
341 | CIE initial instructions. If not, default the rule to | |
342 | UNSPECIFIED. */ | |
343 | if (reg < fs->initial.num_regs) | |
344 | fs->regs.reg[reg] = fs->initial.reg[reg]; | |
345 | else | |
346 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED; | |
347 | ||
348 | if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
349 | complaint (&symfile_complaints, _("\ | |
350 | incomplete CFI data; DW_CFA_restore unspecified\n\ | |
5af949e3 | 351 | register %s (#%d) at %s"), |
a6a5a945 LM |
352 | gdbarch_register_name |
353 | (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)), | |
354 | gdbarch_dwarf2_reg_to_regnum (gdbarch, reg), | |
5af949e3 | 355 | paddress (gdbarch, fs->pc)); |
a6a5a945 LM |
356 | } |
357 | ||
cfc14b3a | 358 | static CORE_ADDR |
ae0d2f24 | 359 | execute_stack_op (gdb_byte *exp, ULONGEST len, int addr_size, |
4a4e5149 | 360 | struct frame_info *this_frame, CORE_ADDR initial) |
cfc14b3a MK |
361 | { |
362 | struct dwarf_expr_context *ctx; | |
363 | CORE_ADDR result; | |
4a227398 | 364 | struct cleanup *old_chain; |
cfc14b3a MK |
365 | |
366 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
367 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
368 | ||
f7fd4728 | 369 | ctx->gdbarch = get_frame_arch (this_frame); |
ae0d2f24 | 370 | ctx->addr_size = addr_size; |
4a4e5149 | 371 | ctx->baton = this_frame; |
cfc14b3a MK |
372 | ctx->read_reg = read_reg; |
373 | ctx->read_mem = read_mem; | |
374 | ctx->get_frame_base = no_get_frame_base; | |
e7802207 | 375 | ctx->get_frame_cfa = no_get_frame_cfa; |
cfc14b3a MK |
376 | ctx->get_tls_address = no_get_tls_address; |
377 | ||
378 | dwarf_expr_push (ctx, initial); | |
379 | dwarf_expr_eval (ctx, exp, len); | |
380 | result = dwarf_expr_fetch (ctx, 0); | |
381 | ||
382 | if (ctx->in_reg) | |
4a4e5149 | 383 | result = read_reg (this_frame, result); |
cfc14b3a | 384 | |
4a227398 | 385 | do_cleanups (old_chain); |
cfc14b3a MK |
386 | |
387 | return result; | |
388 | } | |
389 | \f | |
390 | ||
391 | static void | |
ae0d2f24 | 392 | execute_cfa_program (struct dwarf2_fde *fde, gdb_byte *insn_ptr, |
4a4e5149 | 393 | gdb_byte *insn_end, struct frame_info *this_frame, |
ae0d2f24 | 394 | struct dwarf2_frame_state *fs) |
cfc14b3a | 395 | { |
ae0d2f24 | 396 | int eh_frame_p = fde->eh_frame_p; |
4a4e5149 | 397 | CORE_ADDR pc = get_frame_pc (this_frame); |
cfc14b3a | 398 | int bytes_read; |
4a4e5149 | 399 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
e17a4113 | 400 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
cfc14b3a MK |
401 | |
402 | while (insn_ptr < insn_end && fs->pc <= pc) | |
403 | { | |
852483bc | 404 | gdb_byte insn = *insn_ptr++; |
cfc14b3a MK |
405 | ULONGEST utmp, reg; |
406 | LONGEST offset; | |
407 | ||
408 | if ((insn & 0xc0) == DW_CFA_advance_loc) | |
409 | fs->pc += (insn & 0x3f) * fs->code_align; | |
410 | else if ((insn & 0xc0) == DW_CFA_offset) | |
411 | { | |
412 | reg = insn & 0x3f; | |
4fc771b8 | 413 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
414 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
415 | offset = utmp * fs->data_align; | |
416 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 417 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
418 | fs->regs.reg[reg].loc.offset = offset; |
419 | } | |
420 | else if ((insn & 0xc0) == DW_CFA_restore) | |
421 | { | |
cfc14b3a | 422 | reg = insn & 0x3f; |
a6a5a945 | 423 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
424 | } |
425 | else | |
426 | { | |
427 | switch (insn) | |
428 | { | |
429 | case DW_CFA_set_loc: | |
ae0d2f24 UW |
430 | fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding, |
431 | fde->cie->addr_size, insn_ptr, | |
432 | &bytes_read, fde->initial_location); | |
433 | /* Apply the objfile offset for relocatable objects. */ | |
434 | fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets, | |
435 | SECT_OFF_TEXT (fde->cie->unit->objfile)); | |
cfc14b3a MK |
436 | insn_ptr += bytes_read; |
437 | break; | |
438 | ||
439 | case DW_CFA_advance_loc1: | |
e17a4113 | 440 | utmp = extract_unsigned_integer (insn_ptr, 1, byte_order); |
cfc14b3a MK |
441 | fs->pc += utmp * fs->code_align; |
442 | insn_ptr++; | |
443 | break; | |
444 | case DW_CFA_advance_loc2: | |
e17a4113 | 445 | utmp = extract_unsigned_integer (insn_ptr, 2, byte_order); |
cfc14b3a MK |
446 | fs->pc += utmp * fs->code_align; |
447 | insn_ptr += 2; | |
448 | break; | |
449 | case DW_CFA_advance_loc4: | |
e17a4113 | 450 | utmp = extract_unsigned_integer (insn_ptr, 4, byte_order); |
cfc14b3a MK |
451 | fs->pc += utmp * fs->code_align; |
452 | insn_ptr += 4; | |
453 | break; | |
454 | ||
455 | case DW_CFA_offset_extended: | |
456 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 457 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
458 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
459 | offset = utmp * fs->data_align; | |
460 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 461 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
462 | fs->regs.reg[reg].loc.offset = offset; |
463 | break; | |
464 | ||
465 | case DW_CFA_restore_extended: | |
cfc14b3a | 466 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); |
a6a5a945 | 467 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
468 | break; |
469 | ||
470 | case DW_CFA_undefined: | |
471 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 472 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 473 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 474 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED; |
cfc14b3a MK |
475 | break; |
476 | ||
477 | case DW_CFA_same_value: | |
478 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 479 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 480 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 481 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE; |
cfc14b3a MK |
482 | break; |
483 | ||
484 | case DW_CFA_register: | |
485 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 486 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 487 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
4fc771b8 | 488 | utmp = dwarf2_frame_adjust_regnum (gdbarch, utmp, eh_frame_p); |
cfc14b3a | 489 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 490 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; |
cfc14b3a MK |
491 | fs->regs.reg[reg].loc.reg = utmp; |
492 | break; | |
493 | ||
494 | case DW_CFA_remember_state: | |
495 | { | |
496 | struct dwarf2_frame_state_reg_info *new_rs; | |
497 | ||
498 | new_rs = XMALLOC (struct dwarf2_frame_state_reg_info); | |
499 | *new_rs = fs->regs; | |
500 | fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
501 | fs->regs.prev = new_rs; | |
502 | } | |
503 | break; | |
504 | ||
505 | case DW_CFA_restore_state: | |
506 | { | |
507 | struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev; | |
508 | ||
50ea7769 MK |
509 | if (old_rs == NULL) |
510 | { | |
e2e0b3e5 | 511 | complaint (&symfile_complaints, _("\ |
5af949e3 UW |
512 | bad CFI data; mismatched DW_CFA_restore_state at %s"), |
513 | paddress (gdbarch, fs->pc)); | |
50ea7769 MK |
514 | } |
515 | else | |
516 | { | |
517 | xfree (fs->regs.reg); | |
518 | fs->regs = *old_rs; | |
519 | xfree (old_rs); | |
520 | } | |
cfc14b3a MK |
521 | } |
522 | break; | |
523 | ||
524 | case DW_CFA_def_cfa: | |
2fd481e1 | 525 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
cfc14b3a | 526 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
527 | |
528 | if (fs->armcc_cfa_offsets_sf) | |
529 | utmp *= fs->data_align; | |
530 | ||
2fd481e1 PP |
531 | fs->regs.cfa_offset = utmp; |
532 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
533 | break; |
534 | ||
535 | case DW_CFA_def_cfa_register: | |
2fd481e1 PP |
536 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
537 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
538 | fs->regs.cfa_reg, | |
539 | eh_frame_p); | |
540 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
541 | break; |
542 | ||
543 | case DW_CFA_def_cfa_offset: | |
852483bc | 544 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
545 | |
546 | if (fs->armcc_cfa_offsets_sf) | |
547 | utmp *= fs->data_align; | |
548 | ||
2fd481e1 | 549 | fs->regs.cfa_offset = utmp; |
cfc14b3a MK |
550 | /* cfa_how deliberately not set. */ |
551 | break; | |
552 | ||
a8504492 MK |
553 | case DW_CFA_nop: |
554 | break; | |
555 | ||
cfc14b3a | 556 | case DW_CFA_def_cfa_expression: |
2fd481e1 PP |
557 | insn_ptr = read_uleb128 (insn_ptr, insn_end, |
558 | &fs->regs.cfa_exp_len); | |
559 | fs->regs.cfa_exp = insn_ptr; | |
560 | fs->regs.cfa_how = CFA_EXP; | |
561 | insn_ptr += fs->regs.cfa_exp_len; | |
cfc14b3a MK |
562 | break; |
563 | ||
564 | case DW_CFA_expression: | |
565 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 566 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
567 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
568 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
569 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
570 | fs->regs.reg[reg].exp_len = utmp; | |
05cbe71a | 571 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP; |
cfc14b3a MK |
572 | insn_ptr += utmp; |
573 | break; | |
574 | ||
a8504492 MK |
575 | case DW_CFA_offset_extended_sf: |
576 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 577 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
a8504492 | 578 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
f6da8dd8 | 579 | offset *= fs->data_align; |
a8504492 | 580 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 581 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
a8504492 MK |
582 | fs->regs.reg[reg].loc.offset = offset; |
583 | break; | |
584 | ||
46ea248b AO |
585 | case DW_CFA_val_offset: |
586 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
587 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
588 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
589 | offset = utmp * fs->data_align; | |
590 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
591 | fs->regs.reg[reg].loc.offset = offset; | |
592 | break; | |
593 | ||
594 | case DW_CFA_val_offset_sf: | |
595 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
596 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
597 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
598 | offset *= fs->data_align; | |
599 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
600 | fs->regs.reg[reg].loc.offset = offset; | |
601 | break; | |
602 | ||
603 | case DW_CFA_val_expression: | |
604 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
605 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
606 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
607 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
608 | fs->regs.reg[reg].exp_len = utmp; | |
609 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_EXP; | |
610 | insn_ptr += utmp; | |
611 | break; | |
612 | ||
a8504492 | 613 | case DW_CFA_def_cfa_sf: |
2fd481e1 PP |
614 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
615 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
616 | fs->regs.cfa_reg, | |
617 | eh_frame_p); | |
a8504492 | 618 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
2fd481e1 PP |
619 | fs->regs.cfa_offset = offset * fs->data_align; |
620 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
a8504492 MK |
621 | break; |
622 | ||
623 | case DW_CFA_def_cfa_offset_sf: | |
624 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
2fd481e1 | 625 | fs->regs.cfa_offset = offset * fs->data_align; |
a8504492 | 626 | /* cfa_how deliberately not set. */ |
cfc14b3a MK |
627 | break; |
628 | ||
a77f4086 MK |
629 | case DW_CFA_GNU_window_save: |
630 | /* This is SPARC-specific code, and contains hard-coded | |
631 | constants for the register numbering scheme used by | |
632 | GCC. Rather than having a architecture-specific | |
633 | operation that's only ever used by a single | |
634 | architecture, we provide the implementation here. | |
635 | Incidentally that's what GCC does too in its | |
636 | unwinder. */ | |
637 | { | |
4a4e5149 | 638 | int size = register_size (gdbarch, 0); |
a77f4086 MK |
639 | dwarf2_frame_state_alloc_regs (&fs->regs, 32); |
640 | for (reg = 8; reg < 16; reg++) | |
641 | { | |
642 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; | |
643 | fs->regs.reg[reg].loc.reg = reg + 16; | |
644 | } | |
645 | for (reg = 16; reg < 32; reg++) | |
646 | { | |
647 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
648 | fs->regs.reg[reg].loc.offset = (reg - 16) * size; | |
649 | } | |
650 | } | |
651 | break; | |
652 | ||
cfc14b3a MK |
653 | case DW_CFA_GNU_args_size: |
654 | /* Ignored. */ | |
655 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
656 | break; | |
657 | ||
58894217 JK |
658 | case DW_CFA_GNU_negative_offset_extended: |
659 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 660 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
58894217 JK |
661 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &offset); |
662 | offset *= fs->data_align; | |
663 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
664 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
665 | fs->regs.reg[reg].loc.offset = -offset; | |
666 | break; | |
667 | ||
cfc14b3a | 668 | default: |
e2e0b3e5 | 669 | internal_error (__FILE__, __LINE__, _("Unknown CFI encountered.")); |
cfc14b3a MK |
670 | } |
671 | } | |
672 | } | |
673 | ||
674 | /* Don't allow remember/restore between CIE and FDE programs. */ | |
675 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
676 | fs->regs.prev = NULL; | |
677 | } | |
8f22cb90 | 678 | \f |
cfc14b3a | 679 | |
8f22cb90 | 680 | /* Architecture-specific operations. */ |
cfc14b3a | 681 | |
8f22cb90 MK |
682 | /* Per-architecture data key. */ |
683 | static struct gdbarch_data *dwarf2_frame_data; | |
684 | ||
685 | struct dwarf2_frame_ops | |
686 | { | |
687 | /* Pre-initialize the register state REG for register REGNUM. */ | |
aff37fc1 DM |
688 | void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *, |
689 | struct frame_info *); | |
3ed09a32 | 690 | |
4a4e5149 | 691 | /* Check whether the THIS_FRAME is a signal trampoline. */ |
3ed09a32 | 692 | int (*signal_frame_p) (struct gdbarch *, struct frame_info *); |
4bf8967c | 693 | |
4fc771b8 DJ |
694 | /* Convert .eh_frame register number to DWARF register number, or |
695 | adjust .debug_frame register number. */ | |
696 | int (*adjust_regnum) (struct gdbarch *, int, int); | |
cfc14b3a MK |
697 | }; |
698 | ||
8f22cb90 MK |
699 | /* Default architecture-specific register state initialization |
700 | function. */ | |
701 | ||
702 | static void | |
703 | dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 704 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 705 | struct frame_info *this_frame) |
8f22cb90 MK |
706 | { |
707 | /* If we have a register that acts as a program counter, mark it as | |
708 | a destination for the return address. If we have a register that | |
709 | serves as the stack pointer, arrange for it to be filled with the | |
710 | call frame address (CFA). The other registers are marked as | |
711 | unspecified. | |
712 | ||
713 | We copy the return address to the program counter, since many | |
714 | parts in GDB assume that it is possible to get the return address | |
715 | by unwinding the program counter register. However, on ISA's | |
716 | with a dedicated return address register, the CFI usually only | |
717 | contains information to unwind that return address register. | |
718 | ||
719 | The reason we're treating the stack pointer special here is | |
720 | because in many cases GCC doesn't emit CFI for the stack pointer | |
721 | and implicitly assumes that it is equal to the CFA. This makes | |
722 | some sense since the DWARF specification (version 3, draft 8, | |
723 | p. 102) says that: | |
724 | ||
725 | "Typically, the CFA is defined to be the value of the stack | |
726 | pointer at the call site in the previous frame (which may be | |
727 | different from its value on entry to the current frame)." | |
728 | ||
729 | However, this isn't true for all platforms supported by GCC | |
730 | (e.g. IBM S/390 and zSeries). Those architectures should provide | |
731 | their own architecture-specific initialization function. */ | |
05cbe71a | 732 | |
ad010def | 733 | if (regnum == gdbarch_pc_regnum (gdbarch)) |
8f22cb90 | 734 | reg->how = DWARF2_FRAME_REG_RA; |
ad010def | 735 | else if (regnum == gdbarch_sp_regnum (gdbarch)) |
8f22cb90 MK |
736 | reg->how = DWARF2_FRAME_REG_CFA; |
737 | } | |
05cbe71a | 738 | |
8f22cb90 | 739 | /* Return a default for the architecture-specific operations. */ |
05cbe71a | 740 | |
8f22cb90 | 741 | static void * |
030f20e1 | 742 | dwarf2_frame_init (struct obstack *obstack) |
8f22cb90 MK |
743 | { |
744 | struct dwarf2_frame_ops *ops; | |
745 | ||
030f20e1 | 746 | ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops); |
8f22cb90 MK |
747 | ops->init_reg = dwarf2_frame_default_init_reg; |
748 | return ops; | |
749 | } | |
05cbe71a | 750 | |
8f22cb90 MK |
751 | /* Set the architecture-specific register state initialization |
752 | function for GDBARCH to INIT_REG. */ | |
753 | ||
754 | void | |
755 | dwarf2_frame_set_init_reg (struct gdbarch *gdbarch, | |
756 | void (*init_reg) (struct gdbarch *, int, | |
aff37fc1 DM |
757 | struct dwarf2_frame_state_reg *, |
758 | struct frame_info *)) | |
8f22cb90 | 759 | { |
030f20e1 | 760 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 761 | |
8f22cb90 MK |
762 | ops->init_reg = init_reg; |
763 | } | |
764 | ||
765 | /* Pre-initialize the register state REG for register REGNUM. */ | |
05cbe71a MK |
766 | |
767 | static void | |
768 | dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 769 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 770 | struct frame_info *this_frame) |
05cbe71a | 771 | { |
030f20e1 | 772 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 773 | |
4a4e5149 | 774 | ops->init_reg (gdbarch, regnum, reg, this_frame); |
05cbe71a | 775 | } |
3ed09a32 DJ |
776 | |
777 | /* Set the architecture-specific signal trampoline recognition | |
778 | function for GDBARCH to SIGNAL_FRAME_P. */ | |
779 | ||
780 | void | |
781 | dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch, | |
782 | int (*signal_frame_p) (struct gdbarch *, | |
783 | struct frame_info *)) | |
784 | { | |
785 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
786 | ||
787 | ops->signal_frame_p = signal_frame_p; | |
788 | } | |
789 | ||
790 | /* Query the architecture-specific signal frame recognizer for | |
4a4e5149 | 791 | THIS_FRAME. */ |
3ed09a32 DJ |
792 | |
793 | static int | |
794 | dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch, | |
4a4e5149 | 795 | struct frame_info *this_frame) |
3ed09a32 DJ |
796 | { |
797 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
798 | ||
799 | if (ops->signal_frame_p == NULL) | |
800 | return 0; | |
4a4e5149 | 801 | return ops->signal_frame_p (gdbarch, this_frame); |
3ed09a32 | 802 | } |
4bf8967c | 803 | |
4fc771b8 DJ |
804 | /* Set the architecture-specific adjustment of .eh_frame and .debug_frame |
805 | register numbers. */ | |
4bf8967c AS |
806 | |
807 | void | |
4fc771b8 DJ |
808 | dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch, |
809 | int (*adjust_regnum) (struct gdbarch *, | |
810 | int, int)) | |
4bf8967c AS |
811 | { |
812 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
813 | ||
4fc771b8 | 814 | ops->adjust_regnum = adjust_regnum; |
4bf8967c AS |
815 | } |
816 | ||
4fc771b8 DJ |
817 | /* Translate a .eh_frame register to DWARF register, or adjust a .debug_frame |
818 | register. */ | |
4bf8967c | 819 | |
4fc771b8 DJ |
820 | static int |
821 | dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, int eh_frame_p) | |
4bf8967c AS |
822 | { |
823 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
824 | ||
4fc771b8 | 825 | if (ops->adjust_regnum == NULL) |
4bf8967c | 826 | return regnum; |
4fc771b8 | 827 | return ops->adjust_regnum (gdbarch, regnum, eh_frame_p); |
4bf8967c | 828 | } |
303b6f5d DJ |
829 | |
830 | static void | |
831 | dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs, | |
832 | struct dwarf2_fde *fde) | |
833 | { | |
834 | static const char *arm_idents[] = { | |
835 | "ARM C Compiler, ADS", | |
836 | "Thumb C Compiler, ADS", | |
837 | "ARM C++ Compiler, ADS", | |
838 | "Thumb C++ Compiler, ADS", | |
839 | "ARM/Thumb C/C++ Compiler, RVCT" | |
840 | }; | |
841 | int i; | |
842 | ||
843 | struct symtab *s; | |
844 | ||
845 | s = find_pc_symtab (fs->pc); | |
846 | if (s == NULL || s->producer == NULL) | |
847 | return; | |
848 | ||
849 | for (i = 0; i < ARRAY_SIZE (arm_idents); i++) | |
850 | if (strncmp (s->producer, arm_idents[i], strlen (arm_idents[i])) == 0) | |
851 | { | |
852 | if (fde->cie->version == 1) | |
853 | fs->armcc_cfa_offsets_sf = 1; | |
854 | ||
855 | if (fde->cie->version == 1) | |
856 | fs->armcc_cfa_offsets_reversed = 1; | |
857 | ||
858 | /* The reversed offset problem is present in some compilers | |
859 | using DWARF3, but it was eventually fixed. Check the ARM | |
860 | defined augmentations, which are in the format "armcc" followed | |
861 | by a list of one-character options. The "+" option means | |
862 | this problem is fixed (no quirk needed). If the armcc | |
863 | augmentation is missing, the quirk is needed. */ | |
864 | if (fde->cie->version == 3 | |
865 | && (strncmp (fde->cie->augmentation, "armcc", 5) != 0 | |
866 | || strchr (fde->cie->augmentation + 5, '+') == NULL)) | |
867 | fs->armcc_cfa_offsets_reversed = 1; | |
868 | ||
869 | return; | |
870 | } | |
871 | } | |
8f22cb90 MK |
872 | \f |
873 | ||
874 | struct dwarf2_frame_cache | |
875 | { | |
876 | /* DWARF Call Frame Address. */ | |
877 | CORE_ADDR cfa; | |
878 | ||
0228dfb9 DJ |
879 | /* Set if the return address column was marked as undefined. */ |
880 | int undefined_retaddr; | |
881 | ||
8f22cb90 MK |
882 | /* Saved registers, indexed by GDB register number, not by DWARF |
883 | register number. */ | |
884 | struct dwarf2_frame_state_reg *reg; | |
8d5a9abc MK |
885 | |
886 | /* Return address register. */ | |
887 | struct dwarf2_frame_state_reg retaddr_reg; | |
ae0d2f24 UW |
888 | |
889 | /* Target address size in bytes. */ | |
890 | int addr_size; | |
8f22cb90 | 891 | }; |
05cbe71a | 892 | |
b9362cc7 | 893 | static struct dwarf2_frame_cache * |
4a4e5149 | 894 | dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
895 | { |
896 | struct cleanup *old_chain; | |
4a4e5149 | 897 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
ad010def UW |
898 | const int num_regs = gdbarch_num_regs (gdbarch) |
899 | + gdbarch_num_pseudo_regs (gdbarch); | |
cfc14b3a MK |
900 | struct dwarf2_frame_cache *cache; |
901 | struct dwarf2_frame_state *fs; | |
902 | struct dwarf2_fde *fde; | |
cfc14b3a MK |
903 | |
904 | if (*this_cache) | |
905 | return *this_cache; | |
906 | ||
907 | /* Allocate a new cache. */ | |
908 | cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache); | |
909 | cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg); | |
910 | ||
911 | /* Allocate and initialize the frame state. */ | |
912 | fs = XMALLOC (struct dwarf2_frame_state); | |
913 | memset (fs, 0, sizeof (struct dwarf2_frame_state)); | |
914 | old_chain = make_cleanup (dwarf2_frame_state_free, fs); | |
915 | ||
916 | /* Unwind the PC. | |
917 | ||
4a4e5149 | 918 | Note that if the next frame is never supposed to return (i.e. a call |
cfc14b3a | 919 | to abort), the compiler might optimize away the instruction at |
4a4e5149 | 920 | its return address. As a result the return address will |
cfc14b3a | 921 | point at some random instruction, and the CFI for that |
e4e9607c | 922 | instruction is probably worthless to us. GCC's unwinder solves |
cfc14b3a MK |
923 | this problem by substracting 1 from the return address to get an |
924 | address in the middle of a presumed call instruction (or the | |
925 | instruction in the associated delay slot). This should only be | |
926 | done for "normal" frames and not for resume-type frames (signal | |
e4e9607c | 927 | handlers, sentinel frames, dummy frames). The function |
ad1193e7 | 928 | get_frame_address_in_block does just this. It's not clear how |
e4e9607c MK |
929 | reliable the method is though; there is the potential for the |
930 | register state pre-call being different to that on return. */ | |
4a4e5149 | 931 | fs->pc = get_frame_address_in_block (this_frame); |
cfc14b3a MK |
932 | |
933 | /* Find the correct FDE. */ | |
934 | fde = dwarf2_frame_find_fde (&fs->pc); | |
935 | gdb_assert (fde != NULL); | |
936 | ||
937 | /* Extract any interesting information from the CIE. */ | |
938 | fs->data_align = fde->cie->data_alignment_factor; | |
939 | fs->code_align = fde->cie->code_alignment_factor; | |
940 | fs->retaddr_column = fde->cie->return_address_register; | |
ae0d2f24 | 941 | cache->addr_size = fde->cie->addr_size; |
cfc14b3a | 942 | |
303b6f5d DJ |
943 | /* Check for "quirks" - known bugs in producers. */ |
944 | dwarf2_frame_find_quirks (fs, fde); | |
945 | ||
cfc14b3a | 946 | /* First decode all the insns in the CIE. */ |
ae0d2f24 | 947 | execute_cfa_program (fde, fde->cie->initial_instructions, |
4a4e5149 | 948 | fde->cie->end, this_frame, fs); |
cfc14b3a MK |
949 | |
950 | /* Save the initialized register set. */ | |
951 | fs->initial = fs->regs; | |
952 | fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
953 | ||
954 | /* Then decode the insns in the FDE up to our target PC. */ | |
4a4e5149 | 955 | execute_cfa_program (fde, fde->instructions, fde->end, this_frame, fs); |
cfc14b3a | 956 | |
938f5214 | 957 | /* Calculate the CFA. */ |
2fd481e1 | 958 | switch (fs->regs.cfa_how) |
cfc14b3a MK |
959 | { |
960 | case CFA_REG_OFFSET: | |
2fd481e1 | 961 | cache->cfa = read_reg (this_frame, fs->regs.cfa_reg); |
303b6f5d | 962 | if (fs->armcc_cfa_offsets_reversed) |
2fd481e1 | 963 | cache->cfa -= fs->regs.cfa_offset; |
303b6f5d | 964 | else |
2fd481e1 | 965 | cache->cfa += fs->regs.cfa_offset; |
cfc14b3a MK |
966 | break; |
967 | ||
968 | case CFA_EXP: | |
969 | cache->cfa = | |
2fd481e1 | 970 | execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len, |
4a4e5149 | 971 | cache->addr_size, this_frame, 0); |
cfc14b3a MK |
972 | break; |
973 | ||
974 | default: | |
e2e0b3e5 | 975 | internal_error (__FILE__, __LINE__, _("Unknown CFA rule.")); |
cfc14b3a MK |
976 | } |
977 | ||
05cbe71a | 978 | /* Initialize the register state. */ |
3e2c4033 AC |
979 | { |
980 | int regnum; | |
e4e9607c | 981 | |
3e2c4033 | 982 | for (regnum = 0; regnum < num_regs; regnum++) |
4a4e5149 | 983 | dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], this_frame); |
3e2c4033 AC |
984 | } |
985 | ||
986 | /* Go through the DWARF2 CFI generated table and save its register | |
79c4cb80 MK |
987 | location information in the cache. Note that we don't skip the |
988 | return address column; it's perfectly all right for it to | |
989 | correspond to a real register. If it doesn't correspond to a | |
990 | real register, or if we shouldn't treat it as such, | |
055d23b8 | 991 | gdbarch_dwarf2_reg_to_regnum should be defined to return a number outside |
f57d151a | 992 | the range [0, gdbarch_num_regs). */ |
3e2c4033 AC |
993 | { |
994 | int column; /* CFI speak for "register number". */ | |
e4e9607c | 995 | |
3e2c4033 AC |
996 | for (column = 0; column < fs->regs.num_regs; column++) |
997 | { | |
3e2c4033 | 998 | /* Use the GDB register number as the destination index. */ |
ad010def | 999 | int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column); |
3e2c4033 AC |
1000 | |
1001 | /* If there's no corresponding GDB register, ignore it. */ | |
1002 | if (regnum < 0 || regnum >= num_regs) | |
1003 | continue; | |
1004 | ||
1005 | /* NOTE: cagney/2003-09-05: CFI should specify the disposition | |
e4e9607c MK |
1006 | of all debug info registers. If it doesn't, complain (but |
1007 | not too loudly). It turns out that GCC assumes that an | |
3e2c4033 AC |
1008 | unspecified register implies "same value" when CFI (draft |
1009 | 7) specifies nothing at all. Such a register could equally | |
1010 | be interpreted as "undefined". Also note that this check | |
e4e9607c MK |
1011 | isn't sufficient; it only checks that all registers in the |
1012 | range [0 .. max column] are specified, and won't detect | |
3e2c4033 | 1013 | problems when a debug info register falls outside of the |
e4e9607c | 1014 | table. We need a way of iterating through all the valid |
3e2c4033 | 1015 | DWARF2 register numbers. */ |
05cbe71a | 1016 | if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED) |
f059bf6f AC |
1017 | { |
1018 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
e2e0b3e5 | 1019 | complaint (&symfile_complaints, _("\ |
5af949e3 | 1020 | incomplete CFI data; unspecified registers (e.g., %s) at %s"), |
f059bf6f | 1021 | gdbarch_register_name (gdbarch, regnum), |
5af949e3 | 1022 | paddress (gdbarch, fs->pc)); |
f059bf6f | 1023 | } |
35889917 MK |
1024 | else |
1025 | cache->reg[regnum] = fs->regs.reg[column]; | |
3e2c4033 AC |
1026 | } |
1027 | } | |
cfc14b3a | 1028 | |
8d5a9abc MK |
1029 | /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information |
1030 | we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */ | |
35889917 MK |
1031 | { |
1032 | int regnum; | |
1033 | ||
1034 | for (regnum = 0; regnum < num_regs; regnum++) | |
1035 | { | |
8d5a9abc MK |
1036 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA |
1037 | || cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET) | |
35889917 | 1038 | { |
05cbe71a MK |
1039 | struct dwarf2_frame_state_reg *retaddr_reg = |
1040 | &fs->regs.reg[fs->retaddr_column]; | |
1041 | ||
d4f10bf2 MK |
1042 | /* It seems rather bizarre to specify an "empty" column as |
1043 | the return adress column. However, this is exactly | |
1044 | what GCC does on some targets. It turns out that GCC | |
1045 | assumes that the return address can be found in the | |
1046 | register corresponding to the return address column. | |
8d5a9abc MK |
1047 | Incidentally, that's how we should treat a return |
1048 | address column specifying "same value" too. */ | |
d4f10bf2 | 1049 | if (fs->retaddr_column < fs->regs.num_regs |
05cbe71a MK |
1050 | && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED |
1051 | && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE) | |
8d5a9abc MK |
1052 | { |
1053 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) | |
1054 | cache->reg[regnum] = *retaddr_reg; | |
1055 | else | |
1056 | cache->retaddr_reg = *retaddr_reg; | |
1057 | } | |
35889917 MK |
1058 | else |
1059 | { | |
8d5a9abc MK |
1060 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) |
1061 | { | |
1062 | cache->reg[regnum].loc.reg = fs->retaddr_column; | |
1063 | cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG; | |
1064 | } | |
1065 | else | |
1066 | { | |
1067 | cache->retaddr_reg.loc.reg = fs->retaddr_column; | |
1068 | cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG; | |
1069 | } | |
35889917 MK |
1070 | } |
1071 | } | |
1072 | } | |
1073 | } | |
cfc14b3a | 1074 | |
0228dfb9 DJ |
1075 | if (fs->retaddr_column < fs->regs.num_regs |
1076 | && fs->regs.reg[fs->retaddr_column].how == DWARF2_FRAME_REG_UNDEFINED) | |
1077 | cache->undefined_retaddr = 1; | |
1078 | ||
cfc14b3a MK |
1079 | do_cleanups (old_chain); |
1080 | ||
1081 | *this_cache = cache; | |
1082 | return cache; | |
1083 | } | |
1084 | ||
1085 | static void | |
4a4e5149 | 1086 | dwarf2_frame_this_id (struct frame_info *this_frame, void **this_cache, |
cfc14b3a MK |
1087 | struct frame_id *this_id) |
1088 | { | |
1089 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1090 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a | 1091 | |
0228dfb9 DJ |
1092 | if (cache->undefined_retaddr) |
1093 | return; | |
1094 | ||
4a4e5149 | 1095 | (*this_id) = frame_id_build (cache->cfa, get_frame_func (this_frame)); |
93d42b30 DJ |
1096 | } |
1097 | ||
4a4e5149 DJ |
1098 | static struct value * |
1099 | dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache, | |
1100 | int regnum) | |
93d42b30 | 1101 | { |
4a4e5149 | 1102 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
93d42b30 | 1103 | struct dwarf2_frame_cache *cache = |
4a4e5149 DJ |
1104 | dwarf2_frame_cache (this_frame, this_cache); |
1105 | CORE_ADDR addr; | |
1106 | int realnum; | |
cfc14b3a MK |
1107 | |
1108 | switch (cache->reg[regnum].how) | |
1109 | { | |
05cbe71a | 1110 | case DWARF2_FRAME_REG_UNDEFINED: |
3e2c4033 | 1111 | /* If CFI explicitly specified that the value isn't defined, |
e4e9607c | 1112 | mark it as optimized away; the value isn't available. */ |
4a4e5149 | 1113 | return frame_unwind_got_optimized (this_frame, regnum); |
cfc14b3a | 1114 | |
05cbe71a | 1115 | case DWARF2_FRAME_REG_SAVED_OFFSET: |
4a4e5149 DJ |
1116 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1117 | return frame_unwind_got_memory (this_frame, regnum, addr); | |
cfc14b3a | 1118 | |
05cbe71a | 1119 | case DWARF2_FRAME_REG_SAVED_REG: |
4a4e5149 DJ |
1120 | realnum |
1121 | = gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg); | |
1122 | return frame_unwind_got_register (this_frame, regnum, realnum); | |
cfc14b3a | 1123 | |
05cbe71a | 1124 | case DWARF2_FRAME_REG_SAVED_EXP: |
4a4e5149 DJ |
1125 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1126 | cache->reg[regnum].exp_len, | |
1127 | cache->addr_size, this_frame, cache->cfa); | |
1128 | return frame_unwind_got_memory (this_frame, regnum, addr); | |
cfc14b3a | 1129 | |
46ea248b | 1130 | case DWARF2_FRAME_REG_SAVED_VAL_OFFSET: |
4a4e5149 DJ |
1131 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1132 | return frame_unwind_got_constant (this_frame, regnum, addr); | |
46ea248b AO |
1133 | |
1134 | case DWARF2_FRAME_REG_SAVED_VAL_EXP: | |
4a4e5149 DJ |
1135 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1136 | cache->reg[regnum].exp_len, | |
1137 | cache->addr_size, this_frame, cache->cfa); | |
1138 | return frame_unwind_got_constant (this_frame, regnum, addr); | |
46ea248b | 1139 | |
05cbe71a | 1140 | case DWARF2_FRAME_REG_UNSPECIFIED: |
3e2c4033 AC |
1141 | /* GCC, in its infinite wisdom decided to not provide unwind |
1142 | information for registers that are "same value". Since | |
1143 | DWARF2 (3 draft 7) doesn't define such behavior, said | |
1144 | registers are actually undefined (which is different to CFI | |
1145 | "undefined"). Code above issues a complaint about this. | |
1146 | Here just fudge the books, assume GCC, and that the value is | |
1147 | more inner on the stack. */ | |
4a4e5149 | 1148 | return frame_unwind_got_register (this_frame, regnum, regnum); |
3e2c4033 | 1149 | |
05cbe71a | 1150 | case DWARF2_FRAME_REG_SAME_VALUE: |
4a4e5149 | 1151 | return frame_unwind_got_register (this_frame, regnum, regnum); |
cfc14b3a | 1152 | |
05cbe71a | 1153 | case DWARF2_FRAME_REG_CFA: |
4a4e5149 | 1154 | return frame_unwind_got_address (this_frame, regnum, cache->cfa); |
35889917 | 1155 | |
ea7963f0 | 1156 | case DWARF2_FRAME_REG_CFA_OFFSET: |
4a4e5149 DJ |
1157 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1158 | return frame_unwind_got_address (this_frame, regnum, addr); | |
ea7963f0 | 1159 | |
8d5a9abc | 1160 | case DWARF2_FRAME_REG_RA_OFFSET: |
4a4e5149 DJ |
1161 | addr = cache->reg[regnum].loc.offset; |
1162 | regnum = gdbarch_dwarf2_reg_to_regnum | |
1163 | (gdbarch, cache->retaddr_reg.loc.reg); | |
1164 | addr += get_frame_register_unsigned (this_frame, regnum); | |
1165 | return frame_unwind_got_address (this_frame, regnum, addr); | |
8d5a9abc | 1166 | |
b39cc962 DJ |
1167 | case DWARF2_FRAME_REG_FN: |
1168 | return cache->reg[regnum].loc.fn (this_frame, this_cache, regnum); | |
1169 | ||
cfc14b3a | 1170 | default: |
e2e0b3e5 | 1171 | internal_error (__FILE__, __LINE__, _("Unknown register rule.")); |
cfc14b3a MK |
1172 | } |
1173 | } | |
1174 | ||
4a4e5149 DJ |
1175 | static int |
1176 | dwarf2_frame_sniffer (const struct frame_unwind *self, | |
1177 | struct frame_info *this_frame, void **this_cache) | |
cfc14b3a | 1178 | { |
1ce5d6dd | 1179 | /* Grab an address that is guarenteed to reside somewhere within the |
4a4e5149 | 1180 | function. get_frame_pc(), with a no-return next function, can |
93d42b30 DJ |
1181 | end up returning something past the end of this function's body. |
1182 | If the frame we're sniffing for is a signal frame whose start | |
1183 | address is placed on the stack by the OS, its FDE must | |
4a4e5149 DJ |
1184 | extend one byte before its start address or we could potentially |
1185 | select the FDE of the previous function. */ | |
1186 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); | |
56c987f6 AO |
1187 | struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr); |
1188 | if (!fde) | |
4a4e5149 | 1189 | return 0; |
3ed09a32 DJ |
1190 | |
1191 | /* On some targets, signal trampolines may have unwind information. | |
1192 | We need to recognize them so that we set the frame type | |
1193 | correctly. */ | |
1194 | ||
56c987f6 | 1195 | if (fde->cie->signal_frame |
4a4e5149 DJ |
1196 | || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame), |
1197 | this_frame)) | |
1198 | return self->type == SIGTRAMP_FRAME; | |
1199 | ||
1200 | return self->type != SIGTRAMP_FRAME; | |
1201 | } | |
1202 | ||
1203 | static const struct frame_unwind dwarf2_frame_unwind = | |
1204 | { | |
1205 | NORMAL_FRAME, | |
1206 | dwarf2_frame_this_id, | |
1207 | dwarf2_frame_prev_register, | |
1208 | NULL, | |
1209 | dwarf2_frame_sniffer | |
1210 | }; | |
1211 | ||
1212 | static const struct frame_unwind dwarf2_signal_frame_unwind = | |
1213 | { | |
1214 | SIGTRAMP_FRAME, | |
1215 | dwarf2_frame_this_id, | |
1216 | dwarf2_frame_prev_register, | |
1217 | NULL, | |
1218 | dwarf2_frame_sniffer | |
1219 | }; | |
cfc14b3a | 1220 | |
4a4e5149 DJ |
1221 | /* Append the DWARF-2 frame unwinders to GDBARCH's list. */ |
1222 | ||
1223 | void | |
1224 | dwarf2_append_unwinders (struct gdbarch *gdbarch) | |
1225 | { | |
1226 | frame_unwind_append_unwinder (gdbarch, &dwarf2_frame_unwind); | |
1227 | frame_unwind_append_unwinder (gdbarch, &dwarf2_signal_frame_unwind); | |
cfc14b3a MK |
1228 | } |
1229 | \f | |
1230 | ||
1231 | /* There is no explicitly defined relationship between the CFA and the | |
1232 | location of frame's local variables and arguments/parameters. | |
1233 | Therefore, frame base methods on this page should probably only be | |
1234 | used as a last resort, just to avoid printing total garbage as a | |
1235 | response to the "info frame" command. */ | |
1236 | ||
1237 | static CORE_ADDR | |
4a4e5149 | 1238 | dwarf2_frame_base_address (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
1239 | { |
1240 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1241 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a MK |
1242 | |
1243 | return cache->cfa; | |
1244 | } | |
1245 | ||
1246 | static const struct frame_base dwarf2_frame_base = | |
1247 | { | |
1248 | &dwarf2_frame_unwind, | |
1249 | dwarf2_frame_base_address, | |
1250 | dwarf2_frame_base_address, | |
1251 | dwarf2_frame_base_address | |
1252 | }; | |
1253 | ||
1254 | const struct frame_base * | |
4a4e5149 | 1255 | dwarf2_frame_base_sniffer (struct frame_info *this_frame) |
cfc14b3a | 1256 | { |
4a4e5149 | 1257 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); |
93d42b30 | 1258 | if (dwarf2_frame_find_fde (&block_addr)) |
cfc14b3a MK |
1259 | return &dwarf2_frame_base; |
1260 | ||
1261 | return NULL; | |
1262 | } | |
e7802207 TT |
1263 | |
1264 | /* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from | |
1265 | the DWARF unwinder. This is used to implement | |
1266 | DW_OP_call_frame_cfa. */ | |
1267 | ||
1268 | CORE_ADDR | |
1269 | dwarf2_frame_cfa (struct frame_info *this_frame) | |
1270 | { | |
1271 | while (get_frame_type (this_frame) == INLINE_FRAME) | |
1272 | this_frame = get_prev_frame (this_frame); | |
1273 | /* This restriction could be lifted if other unwinders are known to | |
1274 | compute the frame base in a way compatible with the DWARF | |
1275 | unwinder. */ | |
1276 | if (! frame_unwinder_is (this_frame, &dwarf2_frame_unwind)) | |
1277 | error (_("can't compute CFA for this frame")); | |
1278 | return get_frame_base (this_frame); | |
1279 | } | |
cfc14b3a | 1280 | \f |
8f22cb90 | 1281 | const struct objfile_data *dwarf2_frame_objfile_data; |
0d0e1a63 | 1282 | |
cfc14b3a | 1283 | static unsigned int |
852483bc | 1284 | read_1_byte (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1285 | { |
852483bc | 1286 | return bfd_get_8 (abfd, buf); |
cfc14b3a MK |
1287 | } |
1288 | ||
1289 | static unsigned int | |
852483bc | 1290 | read_4_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1291 | { |
852483bc | 1292 | return bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1293 | } |
1294 | ||
1295 | static ULONGEST | |
852483bc | 1296 | read_8_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1297 | { |
852483bc | 1298 | return bfd_get_64 (abfd, buf); |
cfc14b3a MK |
1299 | } |
1300 | ||
1301 | static ULONGEST | |
852483bc | 1302 | read_unsigned_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1303 | { |
1304 | ULONGEST result; | |
1305 | unsigned int num_read; | |
1306 | int shift; | |
852483bc | 1307 | gdb_byte byte; |
cfc14b3a MK |
1308 | |
1309 | result = 0; | |
1310 | shift = 0; | |
1311 | num_read = 0; | |
1312 | ||
1313 | do | |
1314 | { | |
1315 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1316 | buf++; | |
1317 | num_read++; | |
1318 | result |= ((byte & 0x7f) << shift); | |
1319 | shift += 7; | |
1320 | } | |
1321 | while (byte & 0x80); | |
1322 | ||
1323 | *bytes_read_ptr = num_read; | |
1324 | ||
1325 | return result; | |
1326 | } | |
1327 | ||
1328 | static LONGEST | |
852483bc | 1329 | read_signed_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1330 | { |
1331 | LONGEST result; | |
1332 | int shift; | |
1333 | unsigned int num_read; | |
852483bc | 1334 | gdb_byte byte; |
cfc14b3a MK |
1335 | |
1336 | result = 0; | |
1337 | shift = 0; | |
1338 | num_read = 0; | |
1339 | ||
1340 | do | |
1341 | { | |
1342 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1343 | buf++; | |
1344 | num_read++; | |
1345 | result |= ((byte & 0x7f) << shift); | |
1346 | shift += 7; | |
1347 | } | |
1348 | while (byte & 0x80); | |
1349 | ||
77e0b926 DJ |
1350 | if (shift < 8 * sizeof (result) && (byte & 0x40)) |
1351 | result |= -(((LONGEST)1) << shift); | |
cfc14b3a MK |
1352 | |
1353 | *bytes_read_ptr = num_read; | |
1354 | ||
1355 | return result; | |
1356 | } | |
1357 | ||
1358 | static ULONGEST | |
852483bc | 1359 | read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1360 | { |
1361 | LONGEST result; | |
1362 | ||
852483bc | 1363 | result = bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1364 | if (result == 0xffffffff) |
1365 | { | |
852483bc | 1366 | result = bfd_get_64 (abfd, buf + 4); |
cfc14b3a MK |
1367 | *bytes_read_ptr = 12; |
1368 | } | |
1369 | else | |
1370 | *bytes_read_ptr = 4; | |
1371 | ||
1372 | return result; | |
1373 | } | |
1374 | \f | |
1375 | ||
1376 | /* Pointer encoding helper functions. */ | |
1377 | ||
1378 | /* GCC supports exception handling based on DWARF2 CFI. However, for | |
1379 | technical reasons, it encodes addresses in its FDE's in a different | |
1380 | way. Several "pointer encodings" are supported. The encoding | |
1381 | that's used for a particular FDE is determined by the 'R' | |
1382 | augmentation in the associated CIE. The argument of this | |
1383 | augmentation is a single byte. | |
1384 | ||
1385 | The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a | |
1386 | LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether | |
1387 | the address is signed or unsigned. Bits 4, 5 and 6 encode how the | |
1388 | address should be interpreted (absolute, relative to the current | |
1389 | position in the FDE, ...). Bit 7, indicates that the address | |
1390 | should be dereferenced. */ | |
1391 | ||
852483bc | 1392 | static gdb_byte |
cfc14b3a MK |
1393 | encoding_for_size (unsigned int size) |
1394 | { | |
1395 | switch (size) | |
1396 | { | |
1397 | case 2: | |
1398 | return DW_EH_PE_udata2; | |
1399 | case 4: | |
1400 | return DW_EH_PE_udata4; | |
1401 | case 8: | |
1402 | return DW_EH_PE_udata8; | |
1403 | default: | |
e2e0b3e5 | 1404 | internal_error (__FILE__, __LINE__, _("Unsupported address size")); |
cfc14b3a MK |
1405 | } |
1406 | } | |
1407 | ||
cfc14b3a | 1408 | static CORE_ADDR |
852483bc | 1409 | read_encoded_value (struct comp_unit *unit, gdb_byte encoding, |
ae0d2f24 UW |
1410 | int ptr_len, gdb_byte *buf, unsigned int *bytes_read_ptr, |
1411 | CORE_ADDR func_base) | |
cfc14b3a | 1412 | { |
68f6cf99 | 1413 | ptrdiff_t offset; |
cfc14b3a MK |
1414 | CORE_ADDR base; |
1415 | ||
1416 | /* GCC currently doesn't generate DW_EH_PE_indirect encodings for | |
1417 | FDE's. */ | |
1418 | if (encoding & DW_EH_PE_indirect) | |
1419 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 1420 | _("Unsupported encoding: DW_EH_PE_indirect")); |
cfc14b3a | 1421 | |
68f6cf99 MK |
1422 | *bytes_read_ptr = 0; |
1423 | ||
cfc14b3a MK |
1424 | switch (encoding & 0x70) |
1425 | { | |
1426 | case DW_EH_PE_absptr: | |
1427 | base = 0; | |
1428 | break; | |
1429 | case DW_EH_PE_pcrel: | |
f2fec864 | 1430 | base = bfd_get_section_vma (unit->abfd, unit->dwarf_frame_section); |
852483bc | 1431 | base += (buf - unit->dwarf_frame_buffer); |
cfc14b3a | 1432 | break; |
0912c7f2 MK |
1433 | case DW_EH_PE_datarel: |
1434 | base = unit->dbase; | |
1435 | break; | |
0fd85043 CV |
1436 | case DW_EH_PE_textrel: |
1437 | base = unit->tbase; | |
1438 | break; | |
03ac2a74 | 1439 | case DW_EH_PE_funcrel: |
ae0d2f24 | 1440 | base = func_base; |
03ac2a74 | 1441 | break; |
68f6cf99 MK |
1442 | case DW_EH_PE_aligned: |
1443 | base = 0; | |
852483bc | 1444 | offset = buf - unit->dwarf_frame_buffer; |
68f6cf99 MK |
1445 | if ((offset % ptr_len) != 0) |
1446 | { | |
1447 | *bytes_read_ptr = ptr_len - (offset % ptr_len); | |
1448 | buf += *bytes_read_ptr; | |
1449 | } | |
1450 | break; | |
cfc14b3a | 1451 | default: |
e2e0b3e5 | 1452 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1453 | } |
1454 | ||
b04de778 | 1455 | if ((encoding & 0x07) == 0x00) |
f2fec864 DJ |
1456 | { |
1457 | encoding |= encoding_for_size (ptr_len); | |
1458 | if (bfd_get_sign_extend_vma (unit->abfd)) | |
1459 | encoding |= DW_EH_PE_signed; | |
1460 | } | |
cfc14b3a MK |
1461 | |
1462 | switch (encoding & 0x0f) | |
1463 | { | |
a81b10ae MK |
1464 | case DW_EH_PE_uleb128: |
1465 | { | |
1466 | ULONGEST value; | |
852483bc | 1467 | gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
a7289609 | 1468 | *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1469 | return base + value; |
1470 | } | |
cfc14b3a | 1471 | case DW_EH_PE_udata2: |
68f6cf99 | 1472 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1473 | return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf)); |
1474 | case DW_EH_PE_udata4: | |
68f6cf99 | 1475 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1476 | return (base + bfd_get_32 (unit->abfd, (bfd_byte *) buf)); |
1477 | case DW_EH_PE_udata8: | |
68f6cf99 | 1478 | *bytes_read_ptr += 8; |
cfc14b3a | 1479 | return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf)); |
a81b10ae MK |
1480 | case DW_EH_PE_sleb128: |
1481 | { | |
1482 | LONGEST value; | |
852483bc | 1483 | gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
a7289609 | 1484 | *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1485 | return base + value; |
1486 | } | |
cfc14b3a | 1487 | case DW_EH_PE_sdata2: |
68f6cf99 | 1488 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1489 | return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf)); |
1490 | case DW_EH_PE_sdata4: | |
68f6cf99 | 1491 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1492 | return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf)); |
1493 | case DW_EH_PE_sdata8: | |
68f6cf99 | 1494 | *bytes_read_ptr += 8; |
cfc14b3a MK |
1495 | return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf)); |
1496 | default: | |
e2e0b3e5 | 1497 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1498 | } |
1499 | } | |
1500 | \f | |
1501 | ||
b01c8410 PP |
1502 | static int |
1503 | bsearch_cie_cmp (const void *key, const void *element) | |
cfc14b3a | 1504 | { |
b01c8410 PP |
1505 | ULONGEST cie_pointer = *(ULONGEST *) key; |
1506 | struct dwarf2_cie *cie = *(struct dwarf2_cie **) element; | |
cfc14b3a | 1507 | |
b01c8410 PP |
1508 | if (cie_pointer == cie->cie_pointer) |
1509 | return 0; | |
cfc14b3a | 1510 | |
b01c8410 PP |
1511 | return (cie_pointer < cie->cie_pointer) ? -1 : 1; |
1512 | } | |
1513 | ||
1514 | /* Find CIE with the given CIE_POINTER in CIE_TABLE. */ | |
1515 | static struct dwarf2_cie * | |
1516 | find_cie (struct dwarf2_cie_table *cie_table, ULONGEST cie_pointer) | |
1517 | { | |
1518 | struct dwarf2_cie **p_cie; | |
cfc14b3a | 1519 | |
b01c8410 PP |
1520 | p_cie = bsearch (&cie_pointer, cie_table->entries, cie_table->num_entries, |
1521 | sizeof (cie_table->entries[0]), bsearch_cie_cmp); | |
1522 | if (p_cie != NULL) | |
1523 | return *p_cie; | |
cfc14b3a MK |
1524 | return NULL; |
1525 | } | |
1526 | ||
b01c8410 | 1527 | /* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */ |
cfc14b3a | 1528 | static void |
b01c8410 | 1529 | add_cie (struct dwarf2_cie_table *cie_table, struct dwarf2_cie *cie) |
cfc14b3a | 1530 | { |
b01c8410 PP |
1531 | const int n = cie_table->num_entries; |
1532 | ||
1533 | gdb_assert (n < 1 | |
1534 | || cie_table->entries[n - 1]->cie_pointer < cie->cie_pointer); | |
1535 | ||
1536 | cie_table->entries = | |
1537 | xrealloc (cie_table->entries, (n + 1) * sizeof (cie_table->entries[0])); | |
1538 | cie_table->entries[n] = cie; | |
1539 | cie_table->num_entries = n + 1; | |
1540 | } | |
1541 | ||
1542 | static int | |
1543 | bsearch_fde_cmp (const void *key, const void *element) | |
1544 | { | |
1545 | CORE_ADDR seek_pc = *(CORE_ADDR *) key; | |
1546 | struct dwarf2_fde *fde = *(struct dwarf2_fde **) element; | |
1547 | if (seek_pc < fde->initial_location) | |
1548 | return -1; | |
1549 | if (seek_pc < fde->initial_location + fde->address_range) | |
1550 | return 0; | |
1551 | return 1; | |
cfc14b3a MK |
1552 | } |
1553 | ||
1554 | /* Find the FDE for *PC. Return a pointer to the FDE, and store the | |
1555 | inital location associated with it into *PC. */ | |
1556 | ||
1557 | static struct dwarf2_fde * | |
1558 | dwarf2_frame_find_fde (CORE_ADDR *pc) | |
1559 | { | |
1560 | struct objfile *objfile; | |
1561 | ||
1562 | ALL_OBJFILES (objfile) | |
1563 | { | |
b01c8410 PP |
1564 | struct dwarf2_fde_table *fde_table; |
1565 | struct dwarf2_fde **p_fde; | |
cfc14b3a | 1566 | CORE_ADDR offset; |
b01c8410 | 1567 | CORE_ADDR seek_pc; |
cfc14b3a | 1568 | |
b01c8410 PP |
1569 | fde_table = objfile_data (objfile, dwarf2_frame_objfile_data); |
1570 | if (fde_table == NULL) | |
4ae9ee8e DJ |
1571 | continue; |
1572 | ||
1573 | gdb_assert (objfile->section_offsets); | |
1574 | offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile)); | |
1575 | ||
b01c8410 PP |
1576 | gdb_assert (fde_table->num_entries > 0); |
1577 | if (*pc < offset + fde_table->entries[0]->initial_location) | |
1578 | continue; | |
1579 | ||
1580 | seek_pc = *pc - offset; | |
1581 | p_fde = bsearch (&seek_pc, fde_table->entries, fde_table->num_entries, | |
1582 | sizeof (fde_table->entries[0]), bsearch_fde_cmp); | |
1583 | if (p_fde != NULL) | |
1584 | { | |
1585 | *pc = (*p_fde)->initial_location + offset; | |
1586 | return *p_fde; | |
1587 | } | |
cfc14b3a | 1588 | } |
cfc14b3a MK |
1589 | return NULL; |
1590 | } | |
1591 | ||
b01c8410 | 1592 | /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */ |
cfc14b3a | 1593 | static void |
b01c8410 | 1594 | add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde) |
cfc14b3a | 1595 | { |
b01c8410 PP |
1596 | if (fde->address_range == 0) |
1597 | /* Discard useless FDEs. */ | |
1598 | return; | |
1599 | ||
1600 | fde_table->num_entries += 1; | |
1601 | fde_table->entries = | |
1602 | xrealloc (fde_table->entries, | |
1603 | fde_table->num_entries * sizeof (fde_table->entries[0])); | |
1604 | fde_table->entries[fde_table->num_entries - 1] = fde; | |
cfc14b3a MK |
1605 | } |
1606 | ||
1607 | #ifdef CC_HAS_LONG_LONG | |
1608 | #define DW64_CIE_ID 0xffffffffffffffffULL | |
1609 | #else | |
1610 | #define DW64_CIE_ID ~0 | |
1611 | #endif | |
1612 | ||
852483bc | 1613 | static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start, |
b01c8410 PP |
1614 | int eh_frame_p, |
1615 | struct dwarf2_cie_table *cie_table, | |
1616 | struct dwarf2_fde_table *fde_table); | |
cfc14b3a | 1617 | |
6896c0c7 RH |
1618 | /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise |
1619 | the next byte to be processed. */ | |
852483bc | 1620 | static gdb_byte * |
b01c8410 PP |
1621 | decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1622 | struct dwarf2_cie_table *cie_table, | |
1623 | struct dwarf2_fde_table *fde_table) | |
cfc14b3a | 1624 | { |
5e2b427d | 1625 | struct gdbarch *gdbarch = get_objfile_arch (unit->objfile); |
852483bc | 1626 | gdb_byte *buf, *end; |
cfc14b3a MK |
1627 | LONGEST length; |
1628 | unsigned int bytes_read; | |
6896c0c7 RH |
1629 | int dwarf64_p; |
1630 | ULONGEST cie_id; | |
cfc14b3a | 1631 | ULONGEST cie_pointer; |
cfc14b3a | 1632 | |
6896c0c7 | 1633 | buf = start; |
cfc14b3a MK |
1634 | length = read_initial_length (unit->abfd, buf, &bytes_read); |
1635 | buf += bytes_read; | |
1636 | end = buf + length; | |
1637 | ||
6896c0c7 RH |
1638 | /* Are we still within the section? */ |
1639 | if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
1640 | return NULL; | |
1641 | ||
cfc14b3a MK |
1642 | if (length == 0) |
1643 | return end; | |
1644 | ||
6896c0c7 RH |
1645 | /* Distinguish between 32 and 64-bit encoded frame info. */ |
1646 | dwarf64_p = (bytes_read == 12); | |
cfc14b3a | 1647 | |
6896c0c7 | 1648 | /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */ |
cfc14b3a MK |
1649 | if (eh_frame_p) |
1650 | cie_id = 0; | |
1651 | else if (dwarf64_p) | |
1652 | cie_id = DW64_CIE_ID; | |
6896c0c7 RH |
1653 | else |
1654 | cie_id = DW_CIE_ID; | |
cfc14b3a MK |
1655 | |
1656 | if (dwarf64_p) | |
1657 | { | |
1658 | cie_pointer = read_8_bytes (unit->abfd, buf); | |
1659 | buf += 8; | |
1660 | } | |
1661 | else | |
1662 | { | |
1663 | cie_pointer = read_4_bytes (unit->abfd, buf); | |
1664 | buf += 4; | |
1665 | } | |
1666 | ||
1667 | if (cie_pointer == cie_id) | |
1668 | { | |
1669 | /* This is a CIE. */ | |
1670 | struct dwarf2_cie *cie; | |
1671 | char *augmentation; | |
28ba0b33 | 1672 | unsigned int cie_version; |
cfc14b3a MK |
1673 | |
1674 | /* Record the offset into the .debug_frame section of this CIE. */ | |
1675 | cie_pointer = start - unit->dwarf_frame_buffer; | |
1676 | ||
1677 | /* Check whether we've already read it. */ | |
b01c8410 | 1678 | if (find_cie (cie_table, cie_pointer)) |
cfc14b3a MK |
1679 | return end; |
1680 | ||
1681 | cie = (struct dwarf2_cie *) | |
8b92e4d5 | 1682 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a MK |
1683 | sizeof (struct dwarf2_cie)); |
1684 | cie->initial_instructions = NULL; | |
1685 | cie->cie_pointer = cie_pointer; | |
1686 | ||
1687 | /* The encoding for FDE's in a normal .debug_frame section | |
32b05c07 MK |
1688 | depends on the target address size. */ |
1689 | cie->encoding = DW_EH_PE_absptr; | |
cfc14b3a | 1690 | |
ae0d2f24 UW |
1691 | /* The target address size. For .eh_frame FDEs this is considered |
1692 | equal to the size of a target pointer. For .dwarf_frame FDEs, | |
1693 | this is supposed to be the target address size from the associated | |
1694 | CU header. FIXME: We do not have a good way to determine the | |
1695 | latter. Always use the target pointer size for now. */ | |
5e2b427d | 1696 | cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
ae0d2f24 | 1697 | |
56c987f6 AO |
1698 | /* We'll determine the final value later, but we need to |
1699 | initialize it conservatively. */ | |
1700 | cie->signal_frame = 0; | |
1701 | ||
cfc14b3a | 1702 | /* Check version number. */ |
28ba0b33 PB |
1703 | cie_version = read_1_byte (unit->abfd, buf); |
1704 | if (cie_version != 1 && cie_version != 3) | |
6896c0c7 | 1705 | return NULL; |
303b6f5d | 1706 | cie->version = cie_version; |
cfc14b3a MK |
1707 | buf += 1; |
1708 | ||
1709 | /* Interpret the interesting bits of the augmentation. */ | |
303b6f5d | 1710 | cie->augmentation = augmentation = (char *) buf; |
852483bc | 1711 | buf += (strlen (augmentation) + 1); |
cfc14b3a | 1712 | |
303b6f5d DJ |
1713 | /* Ignore armcc augmentations. We only use them for quirks, |
1714 | and that doesn't happen until later. */ | |
1715 | if (strncmp (augmentation, "armcc", 5) == 0) | |
1716 | augmentation += strlen (augmentation); | |
1717 | ||
cfc14b3a MK |
1718 | /* The GCC 2.x "eh" augmentation has a pointer immediately |
1719 | following the augmentation string, so it must be handled | |
1720 | first. */ | |
1721 | if (augmentation[0] == 'e' && augmentation[1] == 'h') | |
1722 | { | |
1723 | /* Skip. */ | |
5e2b427d | 1724 | buf += gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
cfc14b3a MK |
1725 | augmentation += 2; |
1726 | } | |
1727 | ||
1728 | cie->code_alignment_factor = | |
1729 | read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1730 | buf += bytes_read; | |
1731 | ||
1732 | cie->data_alignment_factor = | |
1733 | read_signed_leb128 (unit->abfd, buf, &bytes_read); | |
1734 | buf += bytes_read; | |
1735 | ||
28ba0b33 PB |
1736 | if (cie_version == 1) |
1737 | { | |
1738 | cie->return_address_register = read_1_byte (unit->abfd, buf); | |
1739 | bytes_read = 1; | |
1740 | } | |
1741 | else | |
1742 | cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf, | |
1743 | &bytes_read); | |
4fc771b8 | 1744 | cie->return_address_register |
5e2b427d | 1745 | = dwarf2_frame_adjust_regnum (gdbarch, |
4fc771b8 DJ |
1746 | cie->return_address_register, |
1747 | eh_frame_p); | |
4bf8967c | 1748 | |
28ba0b33 | 1749 | buf += bytes_read; |
cfc14b3a | 1750 | |
7131cb6e RH |
1751 | cie->saw_z_augmentation = (*augmentation == 'z'); |
1752 | if (cie->saw_z_augmentation) | |
cfc14b3a MK |
1753 | { |
1754 | ULONGEST length; | |
1755 | ||
1756 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1757 | buf += bytes_read; | |
6896c0c7 RH |
1758 | if (buf > end) |
1759 | return NULL; | |
cfc14b3a MK |
1760 | cie->initial_instructions = buf + length; |
1761 | augmentation++; | |
1762 | } | |
1763 | ||
1764 | while (*augmentation) | |
1765 | { | |
1766 | /* "L" indicates a byte showing how the LSDA pointer is encoded. */ | |
1767 | if (*augmentation == 'L') | |
1768 | { | |
1769 | /* Skip. */ | |
1770 | buf++; | |
1771 | augmentation++; | |
1772 | } | |
1773 | ||
1774 | /* "R" indicates a byte indicating how FDE addresses are encoded. */ | |
1775 | else if (*augmentation == 'R') | |
1776 | { | |
1777 | cie->encoding = *buf++; | |
1778 | augmentation++; | |
1779 | } | |
1780 | ||
1781 | /* "P" indicates a personality routine in the CIE augmentation. */ | |
1782 | else if (*augmentation == 'P') | |
1783 | { | |
1234d960 | 1784 | /* Skip. Avoid indirection since we throw away the result. */ |
852483bc | 1785 | gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect; |
ae0d2f24 UW |
1786 | read_encoded_value (unit, encoding, cie->addr_size, |
1787 | buf, &bytes_read, 0); | |
f724bf08 | 1788 | buf += bytes_read; |
cfc14b3a MK |
1789 | augmentation++; |
1790 | } | |
1791 | ||
56c987f6 AO |
1792 | /* "S" indicates a signal frame, such that the return |
1793 | address must not be decremented to locate the call frame | |
1794 | info for the previous frame; it might even be the first | |
1795 | instruction of a function, so decrementing it would take | |
1796 | us to a different function. */ | |
1797 | else if (*augmentation == 'S') | |
1798 | { | |
1799 | cie->signal_frame = 1; | |
1800 | augmentation++; | |
1801 | } | |
1802 | ||
3e9a2e52 DJ |
1803 | /* Otherwise we have an unknown augmentation. Assume that either |
1804 | there is no augmentation data, or we saw a 'z' prefix. */ | |
cfc14b3a MK |
1805 | else |
1806 | { | |
3e9a2e52 DJ |
1807 | if (cie->initial_instructions) |
1808 | buf = cie->initial_instructions; | |
cfc14b3a MK |
1809 | break; |
1810 | } | |
1811 | } | |
1812 | ||
1813 | cie->initial_instructions = buf; | |
1814 | cie->end = end; | |
b01c8410 | 1815 | cie->unit = unit; |
cfc14b3a | 1816 | |
b01c8410 | 1817 | add_cie (cie_table, cie); |
cfc14b3a MK |
1818 | } |
1819 | else | |
1820 | { | |
1821 | /* This is a FDE. */ | |
1822 | struct dwarf2_fde *fde; | |
1823 | ||
6896c0c7 RH |
1824 | /* In an .eh_frame section, the CIE pointer is the delta between the |
1825 | address within the FDE where the CIE pointer is stored and the | |
1826 | address of the CIE. Convert it to an offset into the .eh_frame | |
1827 | section. */ | |
cfc14b3a MK |
1828 | if (eh_frame_p) |
1829 | { | |
cfc14b3a MK |
1830 | cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer; |
1831 | cie_pointer -= (dwarf64_p ? 8 : 4); | |
1832 | } | |
1833 | ||
6896c0c7 RH |
1834 | /* In either case, validate the result is still within the section. */ |
1835 | if (cie_pointer >= unit->dwarf_frame_size) | |
1836 | return NULL; | |
1837 | ||
cfc14b3a | 1838 | fde = (struct dwarf2_fde *) |
8b92e4d5 | 1839 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a | 1840 | sizeof (struct dwarf2_fde)); |
b01c8410 | 1841 | fde->cie = find_cie (cie_table, cie_pointer); |
cfc14b3a MK |
1842 | if (fde->cie == NULL) |
1843 | { | |
1844 | decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer, | |
b01c8410 PP |
1845 | eh_frame_p, cie_table, fde_table); |
1846 | fde->cie = find_cie (cie_table, cie_pointer); | |
cfc14b3a MK |
1847 | } |
1848 | ||
1849 | gdb_assert (fde->cie != NULL); | |
1850 | ||
1851 | fde->initial_location = | |
ae0d2f24 UW |
1852 | read_encoded_value (unit, fde->cie->encoding, fde->cie->addr_size, |
1853 | buf, &bytes_read, 0); | |
cfc14b3a MK |
1854 | buf += bytes_read; |
1855 | ||
1856 | fde->address_range = | |
ae0d2f24 UW |
1857 | read_encoded_value (unit, fde->cie->encoding & 0x0f, |
1858 | fde->cie->addr_size, buf, &bytes_read, 0); | |
cfc14b3a MK |
1859 | buf += bytes_read; |
1860 | ||
7131cb6e RH |
1861 | /* A 'z' augmentation in the CIE implies the presence of an |
1862 | augmentation field in the FDE as well. The only thing known | |
1863 | to be in here at present is the LSDA entry for EH. So we | |
1864 | can skip the whole thing. */ | |
1865 | if (fde->cie->saw_z_augmentation) | |
1866 | { | |
1867 | ULONGEST length; | |
1868 | ||
1869 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1870 | buf += bytes_read + length; | |
6896c0c7 RH |
1871 | if (buf > end) |
1872 | return NULL; | |
7131cb6e RH |
1873 | } |
1874 | ||
cfc14b3a MK |
1875 | fde->instructions = buf; |
1876 | fde->end = end; | |
1877 | ||
4bf8967c AS |
1878 | fde->eh_frame_p = eh_frame_p; |
1879 | ||
b01c8410 | 1880 | add_fde (fde_table, fde); |
cfc14b3a MK |
1881 | } |
1882 | ||
1883 | return end; | |
1884 | } | |
6896c0c7 RH |
1885 | |
1886 | /* Read a CIE or FDE in BUF and decode it. */ | |
852483bc | 1887 | static gdb_byte * |
b01c8410 PP |
1888 | decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1889 | struct dwarf2_cie_table *cie_table, | |
1890 | struct dwarf2_fde_table *fde_table) | |
6896c0c7 RH |
1891 | { |
1892 | enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE; | |
852483bc | 1893 | gdb_byte *ret; |
6896c0c7 RH |
1894 | const char *msg; |
1895 | ptrdiff_t start_offset; | |
1896 | ||
1897 | while (1) | |
1898 | { | |
b01c8410 PP |
1899 | ret = decode_frame_entry_1 (unit, start, eh_frame_p, |
1900 | cie_table, fde_table); | |
6896c0c7 RH |
1901 | if (ret != NULL) |
1902 | break; | |
1903 | ||
1904 | /* We have corrupt input data of some form. */ | |
1905 | ||
1906 | /* ??? Try, weakly, to work around compiler/assembler/linker bugs | |
1907 | and mismatches wrt padding and alignment of debug sections. */ | |
1908 | /* Note that there is no requirement in the standard for any | |
1909 | alignment at all in the frame unwind sections. Testing for | |
1910 | alignment before trying to interpret data would be incorrect. | |
1911 | ||
1912 | However, GCC traditionally arranged for frame sections to be | |
1913 | sized such that the FDE length and CIE fields happen to be | |
1914 | aligned (in theory, for performance). This, unfortunately, | |
1915 | was done with .align directives, which had the side effect of | |
1916 | forcing the section to be aligned by the linker. | |
1917 | ||
1918 | This becomes a problem when you have some other producer that | |
1919 | creates frame sections that are not as strictly aligned. That | |
1920 | produces a hole in the frame info that gets filled by the | |
1921 | linker with zeros. | |
1922 | ||
1923 | The GCC behaviour is arguably a bug, but it's effectively now | |
1924 | part of the ABI, so we're now stuck with it, at least at the | |
1925 | object file level. A smart linker may decide, in the process | |
1926 | of compressing duplicate CIE information, that it can rewrite | |
1927 | the entire output section without this extra padding. */ | |
1928 | ||
1929 | start_offset = start - unit->dwarf_frame_buffer; | |
1930 | if (workaround < ALIGN4 && (start_offset & 3) != 0) | |
1931 | { | |
1932 | start += 4 - (start_offset & 3); | |
1933 | workaround = ALIGN4; | |
1934 | continue; | |
1935 | } | |
1936 | if (workaround < ALIGN8 && (start_offset & 7) != 0) | |
1937 | { | |
1938 | start += 8 - (start_offset & 7); | |
1939 | workaround = ALIGN8; | |
1940 | continue; | |
1941 | } | |
1942 | ||
1943 | /* Nothing left to try. Arrange to return as if we've consumed | |
1944 | the entire input section. Hopefully we'll get valid info from | |
1945 | the other of .debug_frame/.eh_frame. */ | |
1946 | workaround = FAIL; | |
1947 | ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size; | |
1948 | break; | |
1949 | } | |
1950 | ||
1951 | switch (workaround) | |
1952 | { | |
1953 | case NONE: | |
1954 | break; | |
1955 | ||
1956 | case ALIGN4: | |
1957 | complaint (&symfile_complaints, | |
e2e0b3e5 | 1958 | _("Corrupt data in %s:%s; align 4 workaround apparently succeeded"), |
6896c0c7 RH |
1959 | unit->dwarf_frame_section->owner->filename, |
1960 | unit->dwarf_frame_section->name); | |
1961 | break; | |
1962 | ||
1963 | case ALIGN8: | |
1964 | complaint (&symfile_complaints, | |
e2e0b3e5 | 1965 | _("Corrupt data in %s:%s; align 8 workaround apparently succeeded"), |
6896c0c7 RH |
1966 | unit->dwarf_frame_section->owner->filename, |
1967 | unit->dwarf_frame_section->name); | |
1968 | break; | |
1969 | ||
1970 | default: | |
1971 | complaint (&symfile_complaints, | |
e2e0b3e5 | 1972 | _("Corrupt data in %s:%s"), |
6896c0c7 RH |
1973 | unit->dwarf_frame_section->owner->filename, |
1974 | unit->dwarf_frame_section->name); | |
1975 | break; | |
1976 | } | |
1977 | ||
1978 | return ret; | |
1979 | } | |
cfc14b3a MK |
1980 | \f |
1981 | ||
cfc14b3a | 1982 | /* Imported from dwarf2read.c. */ |
dce234bc PP |
1983 | extern void dwarf2_get_section_info (struct objfile *, const char *, asection **, |
1984 | gdb_byte **, bfd_size_type *); | |
cfc14b3a | 1985 | |
b01c8410 PP |
1986 | static int |
1987 | qsort_fde_cmp (const void *a, const void *b) | |
1988 | { | |
1989 | struct dwarf2_fde *aa = *(struct dwarf2_fde **)a; | |
1990 | struct dwarf2_fde *bb = *(struct dwarf2_fde **)b; | |
e5af178f | 1991 | |
b01c8410 | 1992 | if (aa->initial_location == bb->initial_location) |
e5af178f PP |
1993 | { |
1994 | if (aa->address_range != bb->address_range | |
1995 | && aa->eh_frame_p == 0 && bb->eh_frame_p == 0) | |
1996 | /* Linker bug, e.g. gold/10400. | |
1997 | Work around it by keeping stable sort order. */ | |
1998 | return (a < b) ? -1 : 1; | |
1999 | else | |
2000 | /* Put eh_frame entries after debug_frame ones. */ | |
2001 | return aa->eh_frame_p - bb->eh_frame_p; | |
2002 | } | |
b01c8410 PP |
2003 | |
2004 | return (aa->initial_location < bb->initial_location) ? -1 : 1; | |
2005 | } | |
2006 | ||
cfc14b3a MK |
2007 | void |
2008 | dwarf2_build_frame_info (struct objfile *objfile) | |
2009 | { | |
ae0d2f24 | 2010 | struct comp_unit *unit; |
852483bc | 2011 | gdb_byte *frame_ptr; |
b01c8410 PP |
2012 | struct dwarf2_cie_table cie_table; |
2013 | struct dwarf2_fde_table fde_table; | |
2014 | ||
2015 | cie_table.num_entries = 0; | |
2016 | cie_table.entries = NULL; | |
2017 | ||
2018 | fde_table.num_entries = 0; | |
2019 | fde_table.entries = NULL; | |
cfc14b3a MK |
2020 | |
2021 | /* Build a minimal decoding of the DWARF2 compilation unit. */ | |
ae0d2f24 UW |
2022 | unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack, |
2023 | sizeof (struct comp_unit)); | |
2024 | unit->abfd = objfile->obfd; | |
2025 | unit->objfile = objfile; | |
2026 | unit->dbase = 0; | |
2027 | unit->tbase = 0; | |
cfc14b3a | 2028 | |
dce234bc PP |
2029 | dwarf2_get_section_info (objfile, ".eh_frame", |
2030 | &unit->dwarf_frame_section, | |
2031 | &unit->dwarf_frame_buffer, | |
2032 | &unit->dwarf_frame_size); | |
2033 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2034 | { |
0fd85043 | 2035 | asection *got, *txt; |
0912c7f2 | 2036 | |
0912c7f2 | 2037 | /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base |
37b517aa MK |
2038 | that is used for the i386/amd64 target, which currently is |
2039 | the only target in GCC that supports/uses the | |
2040 | DW_EH_PE_datarel encoding. */ | |
ae0d2f24 | 2041 | got = bfd_get_section_by_name (unit->abfd, ".got"); |
0912c7f2 | 2042 | if (got) |
ae0d2f24 | 2043 | unit->dbase = got->vma; |
0912c7f2 | 2044 | |
22c7ba1a MK |
2045 | /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64 |
2046 | so far. */ | |
ae0d2f24 | 2047 | txt = bfd_get_section_by_name (unit->abfd, ".text"); |
0fd85043 | 2048 | if (txt) |
ae0d2f24 | 2049 | unit->tbase = txt->vma; |
0fd85043 | 2050 | |
ae0d2f24 UW |
2051 | frame_ptr = unit->dwarf_frame_buffer; |
2052 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2053 | frame_ptr = decode_frame_entry (unit, frame_ptr, 1, |
2054 | &cie_table, &fde_table); | |
2055 | ||
2056 | if (cie_table.num_entries != 0) | |
2057 | { | |
2058 | /* Reinit cie_table: debug_frame has different CIEs. */ | |
2059 | xfree (cie_table.entries); | |
2060 | cie_table.num_entries = 0; | |
2061 | cie_table.entries = NULL; | |
2062 | } | |
cfc14b3a MK |
2063 | } |
2064 | ||
dce234bc PP |
2065 | dwarf2_get_section_info (objfile, ".debug_frame", |
2066 | &unit->dwarf_frame_section, | |
2067 | &unit->dwarf_frame_buffer, | |
2068 | &unit->dwarf_frame_size); | |
2069 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2070 | { |
ae0d2f24 UW |
2071 | frame_ptr = unit->dwarf_frame_buffer; |
2072 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2073 | frame_ptr = decode_frame_entry (unit, frame_ptr, 0, |
2074 | &cie_table, &fde_table); | |
2075 | } | |
2076 | ||
2077 | /* Discard the cie_table, it is no longer needed. */ | |
2078 | if (cie_table.num_entries != 0) | |
2079 | { | |
2080 | xfree (cie_table.entries); | |
2081 | cie_table.entries = NULL; /* Paranoia. */ | |
2082 | cie_table.num_entries = 0; /* Paranoia. */ | |
2083 | } | |
2084 | ||
2085 | if (fde_table.num_entries != 0) | |
2086 | { | |
2087 | struct dwarf2_fde_table *fde_table2; | |
2088 | int i, j; | |
2089 | ||
2090 | /* Prepare FDE table for lookups. */ | |
2091 | qsort (fde_table.entries, fde_table.num_entries, | |
2092 | sizeof (fde_table.entries[0]), qsort_fde_cmp); | |
2093 | ||
2094 | /* Copy fde_table to obstack: it is needed at runtime. */ | |
2095 | fde_table2 = (struct dwarf2_fde_table *) | |
2096 | obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2)); | |
2097 | ||
2098 | /* Since we'll be doing bsearch, squeeze out identical (except for | |
2099 | eh_frame_p) fde entries so bsearch result is predictable. */ | |
2100 | for (i = 0, j = 0; j < fde_table.num_entries; ++i) | |
2101 | { | |
2102 | const int k = j; | |
2103 | ||
2104 | obstack_grow (&objfile->objfile_obstack, &fde_table.entries[j], | |
2105 | sizeof (fde_table.entries[0])); | |
2106 | while (++j < fde_table.num_entries | |
2107 | && (fde_table.entries[k]->initial_location == | |
2108 | fde_table.entries[j]->initial_location)) | |
2109 | /* Skip. */; | |
2110 | } | |
2111 | fde_table2->entries = obstack_finish (&objfile->objfile_obstack); | |
2112 | fde_table2->num_entries = i; | |
2113 | set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2); | |
2114 | ||
2115 | /* Discard the original fde_table. */ | |
2116 | xfree (fde_table.entries); | |
cfc14b3a MK |
2117 | } |
2118 | } | |
0d0e1a63 MK |
2119 | |
2120 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
2121 | void _initialize_dwarf2_frame (void); | |
2122 | ||
2123 | void | |
2124 | _initialize_dwarf2_frame (void) | |
2125 | { | |
030f20e1 | 2126 | dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init); |
8f22cb90 | 2127 | dwarf2_frame_objfile_data = register_objfile_data (); |
0d0e1a63 | 2128 | } |