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