Commit | Line | Data |
---|---|---|
cfc14b3a MK |
1 | /* Frame unwinder for frames with DWARF Call Frame Information. |
2 | ||
4c38e0a4 | 3 | Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010 |
0fb0cc75 | 4 | Free Software Foundation, Inc. |
cfc14b3a MK |
5 | |
6 | Contributed by Mark Kettenis. | |
7 | ||
8 | This file is part of GDB. | |
9 | ||
10 | This program is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 12 | the Free Software Foundation; either version 3 of the License, or |
cfc14b3a MK |
13 | (at your option) any later version. |
14 | ||
15 | This program is distributed in the hope that it will be useful, | |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
cfc14b3a MK |
22 | |
23 | #include "defs.h" | |
24 | #include "dwarf2expr.h" | |
fa8f86ff | 25 | #include "dwarf2.h" |
cfc14b3a MK |
26 | #include "frame.h" |
27 | #include "frame-base.h" | |
28 | #include "frame-unwind.h" | |
29 | #include "gdbcore.h" | |
30 | #include "gdbtypes.h" | |
31 | #include "symtab.h" | |
32 | #include "objfiles.h" | |
33 | #include "regcache.h" | |
f2da6b3a | 34 | #include "value.h" |
cfc14b3a MK |
35 | |
36 | #include "gdb_assert.h" | |
37 | #include "gdb_string.h" | |
38 | ||
6896c0c7 | 39 | #include "complaints.h" |
cfc14b3a MK |
40 | #include "dwarf2-frame.h" |
41 | ||
ae0d2f24 UW |
42 | struct comp_unit; |
43 | ||
cfc14b3a MK |
44 | /* Call Frame Information (CFI). */ |
45 | ||
46 | /* Common Information Entry (CIE). */ | |
47 | ||
48 | struct dwarf2_cie | |
49 | { | |
ae0d2f24 UW |
50 | /* Computation Unit for this CIE. */ |
51 | struct comp_unit *unit; | |
52 | ||
cfc14b3a MK |
53 | /* Offset into the .debug_frame section where this CIE was found. |
54 | Used to identify this CIE. */ | |
55 | ULONGEST cie_pointer; | |
56 | ||
57 | /* Constant that is factored out of all advance location | |
58 | instructions. */ | |
59 | ULONGEST code_alignment_factor; | |
60 | ||
61 | /* Constants that is factored out of all offset instructions. */ | |
62 | LONGEST data_alignment_factor; | |
63 | ||
64 | /* Return address column. */ | |
65 | ULONGEST return_address_register; | |
66 | ||
67 | /* Instruction sequence to initialize a register set. */ | |
852483bc MK |
68 | gdb_byte *initial_instructions; |
69 | gdb_byte *end; | |
cfc14b3a | 70 | |
303b6f5d DJ |
71 | /* Saved augmentation, in case it's needed later. */ |
72 | char *augmentation; | |
73 | ||
cfc14b3a | 74 | /* Encoding of addresses. */ |
852483bc | 75 | gdb_byte encoding; |
cfc14b3a | 76 | |
ae0d2f24 UW |
77 | /* Target address size in bytes. */ |
78 | int addr_size; | |
79 | ||
7131cb6e RH |
80 | /* True if a 'z' augmentation existed. */ |
81 | unsigned char saw_z_augmentation; | |
82 | ||
56c987f6 AO |
83 | /* True if an 'S' augmentation existed. */ |
84 | unsigned char signal_frame; | |
85 | ||
303b6f5d DJ |
86 | /* The version recorded in the CIE. */ |
87 | unsigned char version; | |
2dc7f7b3 TT |
88 | |
89 | /* The segment size. */ | |
90 | unsigned char segment_size; | |
b01c8410 | 91 | }; |
303b6f5d | 92 | |
b01c8410 PP |
93 | struct dwarf2_cie_table |
94 | { | |
95 | int num_entries; | |
96 | struct dwarf2_cie **entries; | |
cfc14b3a MK |
97 | }; |
98 | ||
99 | /* Frame Description Entry (FDE). */ | |
100 | ||
101 | struct dwarf2_fde | |
102 | { | |
103 | /* CIE for this FDE. */ | |
104 | struct dwarf2_cie *cie; | |
105 | ||
106 | /* First location associated with this FDE. */ | |
107 | CORE_ADDR initial_location; | |
108 | ||
109 | /* Number of bytes of program instructions described by this FDE. */ | |
110 | CORE_ADDR address_range; | |
111 | ||
112 | /* Instruction sequence. */ | |
852483bc MK |
113 | gdb_byte *instructions; |
114 | gdb_byte *end; | |
cfc14b3a | 115 | |
4bf8967c AS |
116 | /* True if this FDE is read from a .eh_frame instead of a .debug_frame |
117 | section. */ | |
118 | unsigned char eh_frame_p; | |
b01c8410 | 119 | }; |
4bf8967c | 120 | |
b01c8410 PP |
121 | struct dwarf2_fde_table |
122 | { | |
123 | int num_entries; | |
124 | struct dwarf2_fde **entries; | |
cfc14b3a MK |
125 | }; |
126 | ||
ae0d2f24 UW |
127 | /* A minimal decoding of DWARF2 compilation units. We only decode |
128 | what's needed to get to the call frame information. */ | |
129 | ||
130 | struct comp_unit | |
131 | { | |
132 | /* Keep the bfd convenient. */ | |
133 | bfd *abfd; | |
134 | ||
135 | struct objfile *objfile; | |
136 | ||
ae0d2f24 UW |
137 | /* Pointer to the .debug_frame section loaded into memory. */ |
138 | gdb_byte *dwarf_frame_buffer; | |
139 | ||
140 | /* Length of the loaded .debug_frame section. */ | |
c098b58b | 141 | bfd_size_type dwarf_frame_size; |
ae0d2f24 UW |
142 | |
143 | /* Pointer to the .debug_frame section. */ | |
144 | asection *dwarf_frame_section; | |
145 | ||
146 | /* Base for DW_EH_PE_datarel encodings. */ | |
147 | bfd_vma dbase; | |
148 | ||
149 | /* Base for DW_EH_PE_textrel encodings. */ | |
150 | bfd_vma tbase; | |
151 | }; | |
152 | ||
ac56253d TT |
153 | static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc, |
154 | CORE_ADDR *out_offset); | |
4fc771b8 DJ |
155 | |
156 | static int dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, | |
157 | int eh_frame_p); | |
ae0d2f24 UW |
158 | |
159 | static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding, | |
0d45f56e | 160 | int ptr_len, const gdb_byte *buf, |
ae0d2f24 UW |
161 | unsigned int *bytes_read_ptr, |
162 | CORE_ADDR func_base); | |
cfc14b3a MK |
163 | \f |
164 | ||
165 | /* Structure describing a frame state. */ | |
166 | ||
167 | struct dwarf2_frame_state | |
168 | { | |
169 | /* Each register save state can be described in terms of a CFA slot, | |
170 | another register, or a location expression. */ | |
171 | struct dwarf2_frame_state_reg_info | |
172 | { | |
05cbe71a | 173 | struct dwarf2_frame_state_reg *reg; |
cfc14b3a MK |
174 | int num_regs; |
175 | ||
2fd481e1 PP |
176 | LONGEST cfa_offset; |
177 | ULONGEST cfa_reg; | |
178 | enum { | |
179 | CFA_UNSET, | |
180 | CFA_REG_OFFSET, | |
181 | CFA_EXP | |
182 | } cfa_how; | |
0d45f56e | 183 | const gdb_byte *cfa_exp; |
2fd481e1 | 184 | |
cfc14b3a MK |
185 | /* Used to implement DW_CFA_remember_state. */ |
186 | struct dwarf2_frame_state_reg_info *prev; | |
187 | } regs; | |
188 | ||
cfc14b3a MK |
189 | /* The PC described by the current frame state. */ |
190 | CORE_ADDR pc; | |
191 | ||
192 | /* Initial register set from the CIE. | |
193 | Used to implement DW_CFA_restore. */ | |
194 | struct dwarf2_frame_state_reg_info initial; | |
195 | ||
196 | /* The information we care about from the CIE. */ | |
197 | LONGEST data_align; | |
198 | ULONGEST code_align; | |
199 | ULONGEST retaddr_column; | |
303b6f5d DJ |
200 | |
201 | /* Flags for known producer quirks. */ | |
202 | ||
203 | /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa | |
204 | and DW_CFA_def_cfa_offset takes a factored offset. */ | |
205 | int armcc_cfa_offsets_sf; | |
206 | ||
207 | /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that | |
208 | the CFA is defined as REG - OFFSET rather than REG + OFFSET. */ | |
209 | int armcc_cfa_offsets_reversed; | |
cfc14b3a MK |
210 | }; |
211 | ||
212 | /* Store the length the expression for the CFA in the `cfa_reg' field, | |
213 | which is unused in that case. */ | |
214 | #define cfa_exp_len cfa_reg | |
215 | ||
f57d151a | 216 | /* Assert that the register set RS is large enough to store gdbarch_num_regs |
cfc14b3a MK |
217 | columns. If necessary, enlarge the register set. */ |
218 | ||
219 | static void | |
220 | dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs, | |
221 | int num_regs) | |
222 | { | |
223 | size_t size = sizeof (struct dwarf2_frame_state_reg); | |
224 | ||
225 | if (num_regs <= rs->num_regs) | |
226 | return; | |
227 | ||
228 | rs->reg = (struct dwarf2_frame_state_reg *) | |
229 | xrealloc (rs->reg, num_regs * size); | |
230 | ||
231 | /* Initialize newly allocated registers. */ | |
2473a4a9 | 232 | memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size); |
cfc14b3a MK |
233 | rs->num_regs = num_regs; |
234 | } | |
235 | ||
236 | /* Copy the register columns in register set RS into newly allocated | |
237 | memory and return a pointer to this newly created copy. */ | |
238 | ||
239 | static struct dwarf2_frame_state_reg * | |
240 | dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs) | |
241 | { | |
d10891d4 | 242 | size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg); |
cfc14b3a MK |
243 | struct dwarf2_frame_state_reg *reg; |
244 | ||
245 | reg = (struct dwarf2_frame_state_reg *) xmalloc (size); | |
246 | memcpy (reg, rs->reg, size); | |
247 | ||
248 | return reg; | |
249 | } | |
250 | ||
251 | /* Release the memory allocated to register set RS. */ | |
252 | ||
253 | static void | |
254 | dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs) | |
255 | { | |
256 | if (rs) | |
257 | { | |
258 | dwarf2_frame_state_free_regs (rs->prev); | |
259 | ||
260 | xfree (rs->reg); | |
261 | xfree (rs); | |
262 | } | |
263 | } | |
264 | ||
265 | /* Release the memory allocated to the frame state FS. */ | |
266 | ||
267 | static void | |
268 | dwarf2_frame_state_free (void *p) | |
269 | { | |
270 | struct dwarf2_frame_state *fs = p; | |
271 | ||
272 | dwarf2_frame_state_free_regs (fs->initial.prev); | |
273 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
274 | xfree (fs->initial.reg); | |
275 | xfree (fs->regs.reg); | |
276 | xfree (fs); | |
277 | } | |
278 | \f | |
279 | ||
280 | /* Helper functions for execute_stack_op. */ | |
281 | ||
282 | static CORE_ADDR | |
283 | read_reg (void *baton, int reg) | |
284 | { | |
4a4e5149 DJ |
285 | struct frame_info *this_frame = (struct frame_info *) baton; |
286 | struct gdbarch *gdbarch = get_frame_arch (this_frame); | |
cfc14b3a | 287 | int regnum; |
852483bc | 288 | gdb_byte *buf; |
cfc14b3a | 289 | |
ad010def | 290 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); |
cfc14b3a | 291 | |
852483bc | 292 | buf = alloca (register_size (gdbarch, regnum)); |
4a4e5149 | 293 | get_frame_register (this_frame, regnum, buf); |
f2da6b3a DJ |
294 | |
295 | /* Convert the register to an integer. This returns a LONGEST | |
296 | rather than a CORE_ADDR, but unpack_pointer does the same thing | |
297 | under the covers, and this makes more sense for non-pointer | |
298 | registers. Maybe read_reg and the associated interfaces should | |
299 | deal with "struct value" instead of CORE_ADDR. */ | |
300 | return unpack_long (register_type (gdbarch, regnum), buf); | |
cfc14b3a MK |
301 | } |
302 | ||
303 | static void | |
852483bc | 304 | read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
cfc14b3a MK |
305 | { |
306 | read_memory (addr, buf, len); | |
307 | } | |
308 | ||
309 | static void | |
0d45f56e | 310 | no_get_frame_base (void *baton, const gdb_byte **start, size_t *length) |
cfc14b3a MK |
311 | { |
312 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 313 | _("Support for DW_OP_fbreg is unimplemented")); |
cfc14b3a MK |
314 | } |
315 | ||
e7802207 TT |
316 | /* Helper function for execute_stack_op. */ |
317 | ||
318 | static CORE_ADDR | |
319 | no_get_frame_cfa (void *baton) | |
320 | { | |
321 | internal_error (__FILE__, __LINE__, | |
322 | _("Support for DW_OP_call_frame_cfa is unimplemented")); | |
323 | } | |
324 | ||
cfc14b3a MK |
325 | static CORE_ADDR |
326 | no_get_tls_address (void *baton, CORE_ADDR offset) | |
327 | { | |
328 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 329 | _("Support for DW_OP_GNU_push_tls_address is unimplemented")); |
cfc14b3a MK |
330 | } |
331 | ||
5c631832 JK |
332 | /* Helper function for execute_stack_op. */ |
333 | ||
334 | static void | |
335 | no_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset) | |
336 | { | |
337 | internal_error (__FILE__, __LINE__, | |
338 | _("Support for DW_OP_call* is invalid in CFI")); | |
339 | } | |
340 | ||
a6a5a945 LM |
341 | /* Execute the required actions for both the DW_CFA_restore and |
342 | DW_CFA_restore_extended instructions. */ | |
343 | static void | |
344 | dwarf2_restore_rule (struct gdbarch *gdbarch, ULONGEST reg_num, | |
345 | struct dwarf2_frame_state *fs, int eh_frame_p) | |
346 | { | |
347 | ULONGEST reg; | |
348 | ||
349 | gdb_assert (fs->initial.reg); | |
350 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg_num, eh_frame_p); | |
351 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
352 | ||
353 | /* Check if this register was explicitly initialized in the | |
354 | CIE initial instructions. If not, default the rule to | |
355 | UNSPECIFIED. */ | |
356 | if (reg < fs->initial.num_regs) | |
357 | fs->regs.reg[reg] = fs->initial.reg[reg]; | |
358 | else | |
359 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED; | |
360 | ||
361 | if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
362 | complaint (&symfile_complaints, _("\ | |
363 | incomplete CFI data; DW_CFA_restore unspecified\n\ | |
5af949e3 | 364 | register %s (#%d) at %s"), |
a6a5a945 LM |
365 | gdbarch_register_name |
366 | (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)), | |
367 | gdbarch_dwarf2_reg_to_regnum (gdbarch, reg), | |
5af949e3 | 368 | paddress (gdbarch, fs->pc)); |
a6a5a945 LM |
369 | } |
370 | ||
cfc14b3a | 371 | static CORE_ADDR |
0d45f56e | 372 | execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size, |
ac56253d TT |
373 | CORE_ADDR offset, struct frame_info *this_frame, |
374 | CORE_ADDR initial, int initial_in_stack_memory) | |
cfc14b3a MK |
375 | { |
376 | struct dwarf_expr_context *ctx; | |
377 | CORE_ADDR result; | |
4a227398 | 378 | struct cleanup *old_chain; |
cfc14b3a MK |
379 | |
380 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
381 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
382 | ||
f7fd4728 | 383 | ctx->gdbarch = get_frame_arch (this_frame); |
ae0d2f24 | 384 | ctx->addr_size = addr_size; |
ac56253d | 385 | ctx->offset = offset; |
4a4e5149 | 386 | ctx->baton = this_frame; |
cfc14b3a MK |
387 | ctx->read_reg = read_reg; |
388 | ctx->read_mem = read_mem; | |
389 | ctx->get_frame_base = no_get_frame_base; | |
e7802207 | 390 | ctx->get_frame_cfa = no_get_frame_cfa; |
cfc14b3a | 391 | ctx->get_tls_address = no_get_tls_address; |
5c631832 | 392 | ctx->dwarf_call = no_dwarf_call; |
cfc14b3a | 393 | |
44353522 | 394 | dwarf_expr_push (ctx, initial, initial_in_stack_memory); |
cfc14b3a | 395 | dwarf_expr_eval (ctx, exp, len); |
cfc14b3a | 396 | |
f2c7657e UW |
397 | if (ctx->location == DWARF_VALUE_MEMORY) |
398 | result = dwarf_expr_fetch_address (ctx, 0); | |
399 | else if (ctx->location == DWARF_VALUE_REGISTER) | |
400 | result = read_reg (this_frame, dwarf_expr_fetch (ctx, 0)); | |
401 | else | |
cec03d70 TT |
402 | { |
403 | /* This is actually invalid DWARF, but if we ever do run across | |
404 | it somehow, we might as well support it. So, instead, report | |
405 | it as unimplemented. */ | |
406 | error (_("Not implemented: computing unwound register using explicit value operator")); | |
407 | } | |
cfc14b3a | 408 | |
4a227398 | 409 | do_cleanups (old_chain); |
cfc14b3a MK |
410 | |
411 | return result; | |
412 | } | |
413 | \f | |
414 | ||
415 | static void | |
0d45f56e TT |
416 | execute_cfa_program (struct dwarf2_fde *fde, const gdb_byte *insn_ptr, |
417 | const gdb_byte *insn_end, struct frame_info *this_frame, | |
ae0d2f24 | 418 | struct dwarf2_frame_state *fs) |
cfc14b3a | 419 | { |
ae0d2f24 | 420 | int eh_frame_p = fde->eh_frame_p; |
4a4e5149 | 421 | CORE_ADDR pc = get_frame_pc (this_frame); |
cfc14b3a | 422 | int bytes_read; |
4a4e5149 | 423 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
e17a4113 | 424 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
cfc14b3a MK |
425 | |
426 | while (insn_ptr < insn_end && fs->pc <= pc) | |
427 | { | |
852483bc | 428 | gdb_byte insn = *insn_ptr++; |
cfc14b3a MK |
429 | ULONGEST utmp, reg; |
430 | LONGEST offset; | |
431 | ||
432 | if ((insn & 0xc0) == DW_CFA_advance_loc) | |
433 | fs->pc += (insn & 0x3f) * fs->code_align; | |
434 | else if ((insn & 0xc0) == DW_CFA_offset) | |
435 | { | |
436 | reg = insn & 0x3f; | |
4fc771b8 | 437 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
438 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
439 | offset = utmp * fs->data_align; | |
440 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 441 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
442 | fs->regs.reg[reg].loc.offset = offset; |
443 | } | |
444 | else if ((insn & 0xc0) == DW_CFA_restore) | |
445 | { | |
cfc14b3a | 446 | reg = insn & 0x3f; |
a6a5a945 | 447 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
448 | } |
449 | else | |
450 | { | |
451 | switch (insn) | |
452 | { | |
453 | case DW_CFA_set_loc: | |
ae0d2f24 UW |
454 | fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding, |
455 | fde->cie->addr_size, insn_ptr, | |
456 | &bytes_read, fde->initial_location); | |
457 | /* Apply the objfile offset for relocatable objects. */ | |
458 | fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets, | |
459 | SECT_OFF_TEXT (fde->cie->unit->objfile)); | |
cfc14b3a MK |
460 | insn_ptr += bytes_read; |
461 | break; | |
462 | ||
463 | case DW_CFA_advance_loc1: | |
e17a4113 | 464 | utmp = extract_unsigned_integer (insn_ptr, 1, byte_order); |
cfc14b3a MK |
465 | fs->pc += utmp * fs->code_align; |
466 | insn_ptr++; | |
467 | break; | |
468 | case DW_CFA_advance_loc2: | |
e17a4113 | 469 | utmp = extract_unsigned_integer (insn_ptr, 2, byte_order); |
cfc14b3a MK |
470 | fs->pc += utmp * fs->code_align; |
471 | insn_ptr += 2; | |
472 | break; | |
473 | case DW_CFA_advance_loc4: | |
e17a4113 | 474 | utmp = extract_unsigned_integer (insn_ptr, 4, byte_order); |
cfc14b3a MK |
475 | fs->pc += utmp * fs->code_align; |
476 | insn_ptr += 4; | |
477 | break; | |
478 | ||
479 | case DW_CFA_offset_extended: | |
480 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 481 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
482 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
483 | offset = utmp * fs->data_align; | |
484 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
05cbe71a | 485 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
cfc14b3a MK |
486 | fs->regs.reg[reg].loc.offset = offset; |
487 | break; | |
488 | ||
489 | case DW_CFA_restore_extended: | |
cfc14b3a | 490 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); |
a6a5a945 | 491 | dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p); |
cfc14b3a MK |
492 | break; |
493 | ||
494 | case DW_CFA_undefined: | |
495 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 496 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 497 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 498 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED; |
cfc14b3a MK |
499 | break; |
500 | ||
501 | case DW_CFA_same_value: | |
502 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 503 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 504 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 505 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE; |
cfc14b3a MK |
506 | break; |
507 | ||
508 | case DW_CFA_register: | |
509 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 510 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a | 511 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
4fc771b8 | 512 | utmp = dwarf2_frame_adjust_regnum (gdbarch, utmp, eh_frame_p); |
cfc14b3a | 513 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 514 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; |
cfc14b3a MK |
515 | fs->regs.reg[reg].loc.reg = utmp; |
516 | break; | |
517 | ||
518 | case DW_CFA_remember_state: | |
519 | { | |
520 | struct dwarf2_frame_state_reg_info *new_rs; | |
521 | ||
522 | new_rs = XMALLOC (struct dwarf2_frame_state_reg_info); | |
523 | *new_rs = fs->regs; | |
524 | fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
525 | fs->regs.prev = new_rs; | |
526 | } | |
527 | break; | |
528 | ||
529 | case DW_CFA_restore_state: | |
530 | { | |
531 | struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev; | |
532 | ||
50ea7769 MK |
533 | if (old_rs == NULL) |
534 | { | |
e2e0b3e5 | 535 | complaint (&symfile_complaints, _("\ |
5af949e3 UW |
536 | bad CFI data; mismatched DW_CFA_restore_state at %s"), |
537 | paddress (gdbarch, fs->pc)); | |
50ea7769 MK |
538 | } |
539 | else | |
540 | { | |
541 | xfree (fs->regs.reg); | |
542 | fs->regs = *old_rs; | |
543 | xfree (old_rs); | |
544 | } | |
cfc14b3a MK |
545 | } |
546 | break; | |
547 | ||
548 | case DW_CFA_def_cfa: | |
2fd481e1 | 549 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
cfc14b3a | 550 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
551 | |
552 | if (fs->armcc_cfa_offsets_sf) | |
553 | utmp *= fs->data_align; | |
554 | ||
2fd481e1 PP |
555 | fs->regs.cfa_offset = utmp; |
556 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
557 | break; |
558 | ||
559 | case DW_CFA_def_cfa_register: | |
2fd481e1 PP |
560 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
561 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
562 | fs->regs.cfa_reg, | |
563 | eh_frame_p); | |
564 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
cfc14b3a MK |
565 | break; |
566 | ||
567 | case DW_CFA_def_cfa_offset: | |
852483bc | 568 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); |
303b6f5d DJ |
569 | |
570 | if (fs->armcc_cfa_offsets_sf) | |
571 | utmp *= fs->data_align; | |
572 | ||
2fd481e1 | 573 | fs->regs.cfa_offset = utmp; |
cfc14b3a MK |
574 | /* cfa_how deliberately not set. */ |
575 | break; | |
576 | ||
a8504492 MK |
577 | case DW_CFA_nop: |
578 | break; | |
579 | ||
cfc14b3a | 580 | case DW_CFA_def_cfa_expression: |
2fd481e1 PP |
581 | insn_ptr = read_uleb128 (insn_ptr, insn_end, |
582 | &fs->regs.cfa_exp_len); | |
583 | fs->regs.cfa_exp = insn_ptr; | |
584 | fs->regs.cfa_how = CFA_EXP; | |
585 | insn_ptr += fs->regs.cfa_exp_len; | |
cfc14b3a MK |
586 | break; |
587 | ||
588 | case DW_CFA_expression: | |
589 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 590 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
cfc14b3a MK |
591 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
592 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
593 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
594 | fs->regs.reg[reg].exp_len = utmp; | |
05cbe71a | 595 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP; |
cfc14b3a MK |
596 | insn_ptr += utmp; |
597 | break; | |
598 | ||
a8504492 MK |
599 | case DW_CFA_offset_extended_sf: |
600 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 601 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
a8504492 | 602 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
f6da8dd8 | 603 | offset *= fs->data_align; |
a8504492 | 604 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); |
05cbe71a | 605 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; |
a8504492 MK |
606 | fs->regs.reg[reg].loc.offset = offset; |
607 | break; | |
608 | ||
46ea248b AO |
609 | case DW_CFA_val_offset: |
610 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
611 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
612 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
613 | offset = utmp * fs->data_align; | |
614 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
615 | fs->regs.reg[reg].loc.offset = offset; | |
616 | break; | |
617 | ||
618 | case DW_CFA_val_offset_sf: | |
619 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
620 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
621 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
622 | offset *= fs->data_align; | |
623 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET; | |
624 | fs->regs.reg[reg].loc.offset = offset; | |
625 | break; | |
626 | ||
627 | case DW_CFA_val_expression: | |
628 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
629 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
630 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
631 | fs->regs.reg[reg].loc.exp = insn_ptr; | |
632 | fs->regs.reg[reg].exp_len = utmp; | |
633 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_EXP; | |
634 | insn_ptr += utmp; | |
635 | break; | |
636 | ||
a8504492 | 637 | case DW_CFA_def_cfa_sf: |
2fd481e1 PP |
638 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg); |
639 | fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, | |
640 | fs->regs.cfa_reg, | |
641 | eh_frame_p); | |
a8504492 | 642 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); |
2fd481e1 PP |
643 | fs->regs.cfa_offset = offset * fs->data_align; |
644 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
a8504492 MK |
645 | break; |
646 | ||
647 | case DW_CFA_def_cfa_offset_sf: | |
648 | insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset); | |
2fd481e1 | 649 | fs->regs.cfa_offset = offset * fs->data_align; |
a8504492 | 650 | /* cfa_how deliberately not set. */ |
cfc14b3a MK |
651 | break; |
652 | ||
a77f4086 MK |
653 | case DW_CFA_GNU_window_save: |
654 | /* This is SPARC-specific code, and contains hard-coded | |
655 | constants for the register numbering scheme used by | |
656 | GCC. Rather than having a architecture-specific | |
657 | operation that's only ever used by a single | |
658 | architecture, we provide the implementation here. | |
659 | Incidentally that's what GCC does too in its | |
660 | unwinder. */ | |
661 | { | |
4a4e5149 | 662 | int size = register_size (gdbarch, 0); |
9a619af0 | 663 | |
a77f4086 MK |
664 | dwarf2_frame_state_alloc_regs (&fs->regs, 32); |
665 | for (reg = 8; reg < 16; reg++) | |
666 | { | |
667 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG; | |
668 | fs->regs.reg[reg].loc.reg = reg + 16; | |
669 | } | |
670 | for (reg = 16; reg < 32; reg++) | |
671 | { | |
672 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
673 | fs->regs.reg[reg].loc.offset = (reg - 16) * size; | |
674 | } | |
675 | } | |
676 | break; | |
677 | ||
cfc14b3a MK |
678 | case DW_CFA_GNU_args_size: |
679 | /* Ignored. */ | |
680 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp); | |
681 | break; | |
682 | ||
58894217 JK |
683 | case DW_CFA_GNU_negative_offset_extended: |
684 | insn_ptr = read_uleb128 (insn_ptr, insn_end, ®); | |
4fc771b8 | 685 | reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p); |
58894217 JK |
686 | insn_ptr = read_uleb128 (insn_ptr, insn_end, &offset); |
687 | offset *= fs->data_align; | |
688 | dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1); | |
689 | fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET; | |
690 | fs->regs.reg[reg].loc.offset = -offset; | |
691 | break; | |
692 | ||
cfc14b3a | 693 | default: |
e2e0b3e5 | 694 | internal_error (__FILE__, __LINE__, _("Unknown CFI encountered.")); |
cfc14b3a MK |
695 | } |
696 | } | |
697 | } | |
698 | ||
699 | /* Don't allow remember/restore between CIE and FDE programs. */ | |
700 | dwarf2_frame_state_free_regs (fs->regs.prev); | |
701 | fs->regs.prev = NULL; | |
702 | } | |
8f22cb90 | 703 | \f |
cfc14b3a | 704 | |
8f22cb90 | 705 | /* Architecture-specific operations. */ |
cfc14b3a | 706 | |
8f22cb90 MK |
707 | /* Per-architecture data key. */ |
708 | static struct gdbarch_data *dwarf2_frame_data; | |
709 | ||
710 | struct dwarf2_frame_ops | |
711 | { | |
712 | /* Pre-initialize the register state REG for register REGNUM. */ | |
aff37fc1 DM |
713 | void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *, |
714 | struct frame_info *); | |
3ed09a32 | 715 | |
4a4e5149 | 716 | /* Check whether the THIS_FRAME is a signal trampoline. */ |
3ed09a32 | 717 | int (*signal_frame_p) (struct gdbarch *, struct frame_info *); |
4bf8967c | 718 | |
4fc771b8 DJ |
719 | /* Convert .eh_frame register number to DWARF register number, or |
720 | adjust .debug_frame register number. */ | |
721 | int (*adjust_regnum) (struct gdbarch *, int, int); | |
cfc14b3a MK |
722 | }; |
723 | ||
8f22cb90 MK |
724 | /* Default architecture-specific register state initialization |
725 | function. */ | |
726 | ||
727 | static void | |
728 | dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 729 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 730 | struct frame_info *this_frame) |
8f22cb90 MK |
731 | { |
732 | /* If we have a register that acts as a program counter, mark it as | |
733 | a destination for the return address. If we have a register that | |
734 | serves as the stack pointer, arrange for it to be filled with the | |
735 | call frame address (CFA). The other registers are marked as | |
736 | unspecified. | |
737 | ||
738 | We copy the return address to the program counter, since many | |
739 | parts in GDB assume that it is possible to get the return address | |
740 | by unwinding the program counter register. However, on ISA's | |
741 | with a dedicated return address register, the CFI usually only | |
742 | contains information to unwind that return address register. | |
743 | ||
744 | The reason we're treating the stack pointer special here is | |
745 | because in many cases GCC doesn't emit CFI for the stack pointer | |
746 | and implicitly assumes that it is equal to the CFA. This makes | |
747 | some sense since the DWARF specification (version 3, draft 8, | |
748 | p. 102) says that: | |
749 | ||
750 | "Typically, the CFA is defined to be the value of the stack | |
751 | pointer at the call site in the previous frame (which may be | |
752 | different from its value on entry to the current frame)." | |
753 | ||
754 | However, this isn't true for all platforms supported by GCC | |
755 | (e.g. IBM S/390 and zSeries). Those architectures should provide | |
756 | their own architecture-specific initialization function. */ | |
05cbe71a | 757 | |
ad010def | 758 | if (regnum == gdbarch_pc_regnum (gdbarch)) |
8f22cb90 | 759 | reg->how = DWARF2_FRAME_REG_RA; |
ad010def | 760 | else if (regnum == gdbarch_sp_regnum (gdbarch)) |
8f22cb90 MK |
761 | reg->how = DWARF2_FRAME_REG_CFA; |
762 | } | |
05cbe71a | 763 | |
8f22cb90 | 764 | /* Return a default for the architecture-specific operations. */ |
05cbe71a | 765 | |
8f22cb90 | 766 | static void * |
030f20e1 | 767 | dwarf2_frame_init (struct obstack *obstack) |
8f22cb90 MK |
768 | { |
769 | struct dwarf2_frame_ops *ops; | |
770 | ||
030f20e1 | 771 | ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops); |
8f22cb90 MK |
772 | ops->init_reg = dwarf2_frame_default_init_reg; |
773 | return ops; | |
774 | } | |
05cbe71a | 775 | |
8f22cb90 MK |
776 | /* Set the architecture-specific register state initialization |
777 | function for GDBARCH to INIT_REG. */ | |
778 | ||
779 | void | |
780 | dwarf2_frame_set_init_reg (struct gdbarch *gdbarch, | |
781 | void (*init_reg) (struct gdbarch *, int, | |
aff37fc1 DM |
782 | struct dwarf2_frame_state_reg *, |
783 | struct frame_info *)) | |
8f22cb90 | 784 | { |
030f20e1 | 785 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 786 | |
8f22cb90 MK |
787 | ops->init_reg = init_reg; |
788 | } | |
789 | ||
790 | /* Pre-initialize the register state REG for register REGNUM. */ | |
05cbe71a MK |
791 | |
792 | static void | |
793 | dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, | |
aff37fc1 | 794 | struct dwarf2_frame_state_reg *reg, |
4a4e5149 | 795 | struct frame_info *this_frame) |
05cbe71a | 796 | { |
030f20e1 | 797 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); |
8f22cb90 | 798 | |
4a4e5149 | 799 | ops->init_reg (gdbarch, regnum, reg, this_frame); |
05cbe71a | 800 | } |
3ed09a32 DJ |
801 | |
802 | /* Set the architecture-specific signal trampoline recognition | |
803 | function for GDBARCH to SIGNAL_FRAME_P. */ | |
804 | ||
805 | void | |
806 | dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch, | |
807 | int (*signal_frame_p) (struct gdbarch *, | |
808 | struct frame_info *)) | |
809 | { | |
810 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
811 | ||
812 | ops->signal_frame_p = signal_frame_p; | |
813 | } | |
814 | ||
815 | /* Query the architecture-specific signal frame recognizer for | |
4a4e5149 | 816 | THIS_FRAME. */ |
3ed09a32 DJ |
817 | |
818 | static int | |
819 | dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch, | |
4a4e5149 | 820 | struct frame_info *this_frame) |
3ed09a32 DJ |
821 | { |
822 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
823 | ||
824 | if (ops->signal_frame_p == NULL) | |
825 | return 0; | |
4a4e5149 | 826 | return ops->signal_frame_p (gdbarch, this_frame); |
3ed09a32 | 827 | } |
4bf8967c | 828 | |
4fc771b8 DJ |
829 | /* Set the architecture-specific adjustment of .eh_frame and .debug_frame |
830 | register numbers. */ | |
4bf8967c AS |
831 | |
832 | void | |
4fc771b8 DJ |
833 | dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch, |
834 | int (*adjust_regnum) (struct gdbarch *, | |
835 | int, int)) | |
4bf8967c AS |
836 | { |
837 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
838 | ||
4fc771b8 | 839 | ops->adjust_regnum = adjust_regnum; |
4bf8967c AS |
840 | } |
841 | ||
4fc771b8 DJ |
842 | /* Translate a .eh_frame register to DWARF register, or adjust a .debug_frame |
843 | register. */ | |
4bf8967c | 844 | |
4fc771b8 DJ |
845 | static int |
846 | dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum, int eh_frame_p) | |
4bf8967c AS |
847 | { |
848 | struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data); | |
849 | ||
4fc771b8 | 850 | if (ops->adjust_regnum == NULL) |
4bf8967c | 851 | return regnum; |
4fc771b8 | 852 | return ops->adjust_regnum (gdbarch, regnum, eh_frame_p); |
4bf8967c | 853 | } |
303b6f5d DJ |
854 | |
855 | static void | |
856 | dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs, | |
857 | struct dwarf2_fde *fde) | |
858 | { | |
303b6f5d DJ |
859 | struct symtab *s; |
860 | ||
861 | s = find_pc_symtab (fs->pc); | |
a6c727b2 | 862 | if (s == NULL) |
303b6f5d DJ |
863 | return; |
864 | ||
a6c727b2 DJ |
865 | if (producer_is_realview (s->producer)) |
866 | { | |
867 | if (fde->cie->version == 1) | |
868 | fs->armcc_cfa_offsets_sf = 1; | |
869 | ||
870 | if (fde->cie->version == 1) | |
871 | fs->armcc_cfa_offsets_reversed = 1; | |
872 | ||
873 | /* The reversed offset problem is present in some compilers | |
874 | using DWARF3, but it was eventually fixed. Check the ARM | |
875 | defined augmentations, which are in the format "armcc" followed | |
876 | by a list of one-character options. The "+" option means | |
877 | this problem is fixed (no quirk needed). If the armcc | |
878 | augmentation is missing, the quirk is needed. */ | |
879 | if (fde->cie->version == 3 | |
880 | && (strncmp (fde->cie->augmentation, "armcc", 5) != 0 | |
881 | || strchr (fde->cie->augmentation + 5, '+') == NULL)) | |
882 | fs->armcc_cfa_offsets_reversed = 1; | |
883 | ||
884 | return; | |
885 | } | |
303b6f5d | 886 | } |
8f22cb90 MK |
887 | \f |
888 | ||
889 | struct dwarf2_frame_cache | |
890 | { | |
891 | /* DWARF Call Frame Address. */ | |
892 | CORE_ADDR cfa; | |
893 | ||
0228dfb9 DJ |
894 | /* Set if the return address column was marked as undefined. */ |
895 | int undefined_retaddr; | |
896 | ||
8f22cb90 MK |
897 | /* Saved registers, indexed by GDB register number, not by DWARF |
898 | register number. */ | |
899 | struct dwarf2_frame_state_reg *reg; | |
8d5a9abc MK |
900 | |
901 | /* Return address register. */ | |
902 | struct dwarf2_frame_state_reg retaddr_reg; | |
ae0d2f24 UW |
903 | |
904 | /* Target address size in bytes. */ | |
905 | int addr_size; | |
ac56253d TT |
906 | |
907 | /* The .text offset. */ | |
908 | CORE_ADDR text_offset; | |
8f22cb90 | 909 | }; |
05cbe71a | 910 | |
b9362cc7 | 911 | static struct dwarf2_frame_cache * |
4a4e5149 | 912 | dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
913 | { |
914 | struct cleanup *old_chain; | |
4a4e5149 | 915 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
ad010def UW |
916 | const int num_regs = gdbarch_num_regs (gdbarch) |
917 | + gdbarch_num_pseudo_regs (gdbarch); | |
cfc14b3a MK |
918 | struct dwarf2_frame_cache *cache; |
919 | struct dwarf2_frame_state *fs; | |
920 | struct dwarf2_fde *fde; | |
cfc14b3a MK |
921 | |
922 | if (*this_cache) | |
923 | return *this_cache; | |
924 | ||
925 | /* Allocate a new cache. */ | |
926 | cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache); | |
927 | cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg); | |
928 | ||
929 | /* Allocate and initialize the frame state. */ | |
930 | fs = XMALLOC (struct dwarf2_frame_state); | |
931 | memset (fs, 0, sizeof (struct dwarf2_frame_state)); | |
932 | old_chain = make_cleanup (dwarf2_frame_state_free, fs); | |
933 | ||
934 | /* Unwind the PC. | |
935 | ||
4a4e5149 | 936 | Note that if the next frame is never supposed to return (i.e. a call |
cfc14b3a | 937 | to abort), the compiler might optimize away the instruction at |
4a4e5149 | 938 | its return address. As a result the return address will |
cfc14b3a | 939 | point at some random instruction, and the CFI for that |
e4e9607c | 940 | instruction is probably worthless to us. GCC's unwinder solves |
cfc14b3a MK |
941 | this problem by substracting 1 from the return address to get an |
942 | address in the middle of a presumed call instruction (or the | |
943 | instruction in the associated delay slot). This should only be | |
944 | done for "normal" frames and not for resume-type frames (signal | |
e4e9607c | 945 | handlers, sentinel frames, dummy frames). The function |
ad1193e7 | 946 | get_frame_address_in_block does just this. It's not clear how |
e4e9607c MK |
947 | reliable the method is though; there is the potential for the |
948 | register state pre-call being different to that on return. */ | |
4a4e5149 | 949 | fs->pc = get_frame_address_in_block (this_frame); |
cfc14b3a MK |
950 | |
951 | /* Find the correct FDE. */ | |
ac56253d | 952 | fde = dwarf2_frame_find_fde (&fs->pc, &cache->text_offset); |
cfc14b3a MK |
953 | gdb_assert (fde != NULL); |
954 | ||
955 | /* Extract any interesting information from the CIE. */ | |
956 | fs->data_align = fde->cie->data_alignment_factor; | |
957 | fs->code_align = fde->cie->code_alignment_factor; | |
958 | fs->retaddr_column = fde->cie->return_address_register; | |
ae0d2f24 | 959 | cache->addr_size = fde->cie->addr_size; |
cfc14b3a | 960 | |
303b6f5d DJ |
961 | /* Check for "quirks" - known bugs in producers. */ |
962 | dwarf2_frame_find_quirks (fs, fde); | |
963 | ||
cfc14b3a | 964 | /* First decode all the insns in the CIE. */ |
ae0d2f24 | 965 | execute_cfa_program (fde, fde->cie->initial_instructions, |
4a4e5149 | 966 | fde->cie->end, this_frame, fs); |
cfc14b3a MK |
967 | |
968 | /* Save the initialized register set. */ | |
969 | fs->initial = fs->regs; | |
970 | fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs); | |
971 | ||
972 | /* Then decode the insns in the FDE up to our target PC. */ | |
4a4e5149 | 973 | execute_cfa_program (fde, fde->instructions, fde->end, this_frame, fs); |
cfc14b3a | 974 | |
938f5214 | 975 | /* Calculate the CFA. */ |
2fd481e1 | 976 | switch (fs->regs.cfa_how) |
cfc14b3a MK |
977 | { |
978 | case CFA_REG_OFFSET: | |
2fd481e1 | 979 | cache->cfa = read_reg (this_frame, fs->regs.cfa_reg); |
303b6f5d | 980 | if (fs->armcc_cfa_offsets_reversed) |
2fd481e1 | 981 | cache->cfa -= fs->regs.cfa_offset; |
303b6f5d | 982 | else |
2fd481e1 | 983 | cache->cfa += fs->regs.cfa_offset; |
cfc14b3a MK |
984 | break; |
985 | ||
986 | case CFA_EXP: | |
987 | cache->cfa = | |
2fd481e1 | 988 | execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len, |
ac56253d TT |
989 | cache->addr_size, cache->text_offset, |
990 | this_frame, 0, 0); | |
cfc14b3a MK |
991 | break; |
992 | ||
993 | default: | |
e2e0b3e5 | 994 | internal_error (__FILE__, __LINE__, _("Unknown CFA rule.")); |
cfc14b3a MK |
995 | } |
996 | ||
05cbe71a | 997 | /* Initialize the register state. */ |
3e2c4033 AC |
998 | { |
999 | int regnum; | |
e4e9607c | 1000 | |
3e2c4033 | 1001 | for (regnum = 0; regnum < num_regs; regnum++) |
4a4e5149 | 1002 | dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], this_frame); |
3e2c4033 AC |
1003 | } |
1004 | ||
1005 | /* Go through the DWARF2 CFI generated table and save its register | |
79c4cb80 MK |
1006 | location information in the cache. Note that we don't skip the |
1007 | return address column; it's perfectly all right for it to | |
1008 | correspond to a real register. If it doesn't correspond to a | |
1009 | real register, or if we shouldn't treat it as such, | |
055d23b8 | 1010 | gdbarch_dwarf2_reg_to_regnum should be defined to return a number outside |
f57d151a | 1011 | the range [0, gdbarch_num_regs). */ |
3e2c4033 AC |
1012 | { |
1013 | int column; /* CFI speak for "register number". */ | |
e4e9607c | 1014 | |
3e2c4033 AC |
1015 | for (column = 0; column < fs->regs.num_regs; column++) |
1016 | { | |
3e2c4033 | 1017 | /* Use the GDB register number as the destination index. */ |
ad010def | 1018 | int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column); |
3e2c4033 AC |
1019 | |
1020 | /* If there's no corresponding GDB register, ignore it. */ | |
1021 | if (regnum < 0 || regnum >= num_regs) | |
1022 | continue; | |
1023 | ||
1024 | /* NOTE: cagney/2003-09-05: CFI should specify the disposition | |
e4e9607c MK |
1025 | of all debug info registers. If it doesn't, complain (but |
1026 | not too loudly). It turns out that GCC assumes that an | |
3e2c4033 AC |
1027 | unspecified register implies "same value" when CFI (draft |
1028 | 7) specifies nothing at all. Such a register could equally | |
1029 | be interpreted as "undefined". Also note that this check | |
e4e9607c MK |
1030 | isn't sufficient; it only checks that all registers in the |
1031 | range [0 .. max column] are specified, and won't detect | |
3e2c4033 | 1032 | problems when a debug info register falls outside of the |
e4e9607c | 1033 | table. We need a way of iterating through all the valid |
3e2c4033 | 1034 | DWARF2 register numbers. */ |
05cbe71a | 1035 | if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED) |
f059bf6f AC |
1036 | { |
1037 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED) | |
e2e0b3e5 | 1038 | complaint (&symfile_complaints, _("\ |
5af949e3 | 1039 | incomplete CFI data; unspecified registers (e.g., %s) at %s"), |
f059bf6f | 1040 | gdbarch_register_name (gdbarch, regnum), |
5af949e3 | 1041 | paddress (gdbarch, fs->pc)); |
f059bf6f | 1042 | } |
35889917 MK |
1043 | else |
1044 | cache->reg[regnum] = fs->regs.reg[column]; | |
3e2c4033 AC |
1045 | } |
1046 | } | |
cfc14b3a | 1047 | |
8d5a9abc MK |
1048 | /* Eliminate any DWARF2_FRAME_REG_RA rules, and save the information |
1049 | we need for evaluating DWARF2_FRAME_REG_RA_OFFSET rules. */ | |
35889917 MK |
1050 | { |
1051 | int regnum; | |
1052 | ||
1053 | for (regnum = 0; regnum < num_regs; regnum++) | |
1054 | { | |
8d5a9abc MK |
1055 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA |
1056 | || cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET) | |
35889917 | 1057 | { |
05cbe71a MK |
1058 | struct dwarf2_frame_state_reg *retaddr_reg = |
1059 | &fs->regs.reg[fs->retaddr_column]; | |
1060 | ||
d4f10bf2 MK |
1061 | /* It seems rather bizarre to specify an "empty" column as |
1062 | the return adress column. However, this is exactly | |
1063 | what GCC does on some targets. It turns out that GCC | |
1064 | assumes that the return address can be found in the | |
1065 | register corresponding to the return address column. | |
8d5a9abc MK |
1066 | Incidentally, that's how we should treat a return |
1067 | address column specifying "same value" too. */ | |
d4f10bf2 | 1068 | if (fs->retaddr_column < fs->regs.num_regs |
05cbe71a MK |
1069 | && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED |
1070 | && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE) | |
8d5a9abc MK |
1071 | { |
1072 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) | |
1073 | cache->reg[regnum] = *retaddr_reg; | |
1074 | else | |
1075 | cache->retaddr_reg = *retaddr_reg; | |
1076 | } | |
35889917 MK |
1077 | else |
1078 | { | |
8d5a9abc MK |
1079 | if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA) |
1080 | { | |
1081 | cache->reg[regnum].loc.reg = fs->retaddr_column; | |
1082 | cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG; | |
1083 | } | |
1084 | else | |
1085 | { | |
1086 | cache->retaddr_reg.loc.reg = fs->retaddr_column; | |
1087 | cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG; | |
1088 | } | |
35889917 MK |
1089 | } |
1090 | } | |
1091 | } | |
1092 | } | |
cfc14b3a | 1093 | |
0228dfb9 DJ |
1094 | if (fs->retaddr_column < fs->regs.num_regs |
1095 | && fs->regs.reg[fs->retaddr_column].how == DWARF2_FRAME_REG_UNDEFINED) | |
1096 | cache->undefined_retaddr = 1; | |
1097 | ||
cfc14b3a MK |
1098 | do_cleanups (old_chain); |
1099 | ||
1100 | *this_cache = cache; | |
1101 | return cache; | |
1102 | } | |
1103 | ||
1104 | static void | |
4a4e5149 | 1105 | dwarf2_frame_this_id (struct frame_info *this_frame, void **this_cache, |
cfc14b3a MK |
1106 | struct frame_id *this_id) |
1107 | { | |
1108 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1109 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a | 1110 | |
0228dfb9 DJ |
1111 | if (cache->undefined_retaddr) |
1112 | return; | |
1113 | ||
4a4e5149 | 1114 | (*this_id) = frame_id_build (cache->cfa, get_frame_func (this_frame)); |
93d42b30 DJ |
1115 | } |
1116 | ||
4a4e5149 DJ |
1117 | static struct value * |
1118 | dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache, | |
1119 | int regnum) | |
93d42b30 | 1120 | { |
4a4e5149 | 1121 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
93d42b30 | 1122 | struct dwarf2_frame_cache *cache = |
4a4e5149 DJ |
1123 | dwarf2_frame_cache (this_frame, this_cache); |
1124 | CORE_ADDR addr; | |
1125 | int realnum; | |
cfc14b3a MK |
1126 | |
1127 | switch (cache->reg[regnum].how) | |
1128 | { | |
05cbe71a | 1129 | case DWARF2_FRAME_REG_UNDEFINED: |
3e2c4033 | 1130 | /* If CFI explicitly specified that the value isn't defined, |
e4e9607c | 1131 | mark it as optimized away; the value isn't available. */ |
4a4e5149 | 1132 | return frame_unwind_got_optimized (this_frame, regnum); |
cfc14b3a | 1133 | |
05cbe71a | 1134 | case DWARF2_FRAME_REG_SAVED_OFFSET: |
4a4e5149 DJ |
1135 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1136 | return frame_unwind_got_memory (this_frame, regnum, addr); | |
cfc14b3a | 1137 | |
05cbe71a | 1138 | case DWARF2_FRAME_REG_SAVED_REG: |
4a4e5149 DJ |
1139 | realnum |
1140 | = gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg); | |
1141 | return frame_unwind_got_register (this_frame, regnum, realnum); | |
cfc14b3a | 1142 | |
05cbe71a | 1143 | case DWARF2_FRAME_REG_SAVED_EXP: |
4a4e5149 DJ |
1144 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1145 | cache->reg[regnum].exp_len, | |
ac56253d TT |
1146 | cache->addr_size, cache->text_offset, |
1147 | this_frame, cache->cfa, 1); | |
4a4e5149 | 1148 | return frame_unwind_got_memory (this_frame, regnum, addr); |
cfc14b3a | 1149 | |
46ea248b | 1150 | case DWARF2_FRAME_REG_SAVED_VAL_OFFSET: |
4a4e5149 DJ |
1151 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1152 | return frame_unwind_got_constant (this_frame, regnum, addr); | |
46ea248b AO |
1153 | |
1154 | case DWARF2_FRAME_REG_SAVED_VAL_EXP: | |
4a4e5149 DJ |
1155 | addr = execute_stack_op (cache->reg[regnum].loc.exp, |
1156 | cache->reg[regnum].exp_len, | |
ac56253d TT |
1157 | cache->addr_size, cache->text_offset, |
1158 | this_frame, cache->cfa, 1); | |
4a4e5149 | 1159 | return frame_unwind_got_constant (this_frame, regnum, addr); |
46ea248b | 1160 | |
05cbe71a | 1161 | case DWARF2_FRAME_REG_UNSPECIFIED: |
3e2c4033 AC |
1162 | /* GCC, in its infinite wisdom decided to not provide unwind |
1163 | information for registers that are "same value". Since | |
1164 | DWARF2 (3 draft 7) doesn't define such behavior, said | |
1165 | registers are actually undefined (which is different to CFI | |
1166 | "undefined"). Code above issues a complaint about this. | |
1167 | Here just fudge the books, assume GCC, and that the value is | |
1168 | more inner on the stack. */ | |
4a4e5149 | 1169 | return frame_unwind_got_register (this_frame, regnum, regnum); |
3e2c4033 | 1170 | |
05cbe71a | 1171 | case DWARF2_FRAME_REG_SAME_VALUE: |
4a4e5149 | 1172 | return frame_unwind_got_register (this_frame, regnum, regnum); |
cfc14b3a | 1173 | |
05cbe71a | 1174 | case DWARF2_FRAME_REG_CFA: |
4a4e5149 | 1175 | return frame_unwind_got_address (this_frame, regnum, cache->cfa); |
35889917 | 1176 | |
ea7963f0 | 1177 | case DWARF2_FRAME_REG_CFA_OFFSET: |
4a4e5149 DJ |
1178 | addr = cache->cfa + cache->reg[regnum].loc.offset; |
1179 | return frame_unwind_got_address (this_frame, regnum, addr); | |
ea7963f0 | 1180 | |
8d5a9abc | 1181 | case DWARF2_FRAME_REG_RA_OFFSET: |
4a4e5149 DJ |
1182 | addr = cache->reg[regnum].loc.offset; |
1183 | regnum = gdbarch_dwarf2_reg_to_regnum | |
1184 | (gdbarch, cache->retaddr_reg.loc.reg); | |
1185 | addr += get_frame_register_unsigned (this_frame, regnum); | |
1186 | return frame_unwind_got_address (this_frame, regnum, addr); | |
8d5a9abc | 1187 | |
b39cc962 DJ |
1188 | case DWARF2_FRAME_REG_FN: |
1189 | return cache->reg[regnum].loc.fn (this_frame, this_cache, regnum); | |
1190 | ||
cfc14b3a | 1191 | default: |
e2e0b3e5 | 1192 | internal_error (__FILE__, __LINE__, _("Unknown register rule.")); |
cfc14b3a MK |
1193 | } |
1194 | } | |
1195 | ||
4a4e5149 DJ |
1196 | static int |
1197 | dwarf2_frame_sniffer (const struct frame_unwind *self, | |
1198 | struct frame_info *this_frame, void **this_cache) | |
cfc14b3a | 1199 | { |
1ce5d6dd | 1200 | /* Grab an address that is guarenteed to reside somewhere within the |
4a4e5149 | 1201 | function. get_frame_pc(), with a no-return next function, can |
93d42b30 DJ |
1202 | end up returning something past the end of this function's body. |
1203 | If the frame we're sniffing for is a signal frame whose start | |
1204 | address is placed on the stack by the OS, its FDE must | |
4a4e5149 DJ |
1205 | extend one byte before its start address or we could potentially |
1206 | select the FDE of the previous function. */ | |
1207 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); | |
ac56253d | 1208 | struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr, NULL); |
9a619af0 | 1209 | |
56c987f6 | 1210 | if (!fde) |
4a4e5149 | 1211 | return 0; |
3ed09a32 DJ |
1212 | |
1213 | /* On some targets, signal trampolines may have unwind information. | |
1214 | We need to recognize them so that we set the frame type | |
1215 | correctly. */ | |
1216 | ||
56c987f6 | 1217 | if (fde->cie->signal_frame |
4a4e5149 DJ |
1218 | || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame), |
1219 | this_frame)) | |
1220 | return self->type == SIGTRAMP_FRAME; | |
1221 | ||
1222 | return self->type != SIGTRAMP_FRAME; | |
1223 | } | |
1224 | ||
1225 | static const struct frame_unwind dwarf2_frame_unwind = | |
1226 | { | |
1227 | NORMAL_FRAME, | |
1228 | dwarf2_frame_this_id, | |
1229 | dwarf2_frame_prev_register, | |
1230 | NULL, | |
1231 | dwarf2_frame_sniffer | |
1232 | }; | |
1233 | ||
1234 | static const struct frame_unwind dwarf2_signal_frame_unwind = | |
1235 | { | |
1236 | SIGTRAMP_FRAME, | |
1237 | dwarf2_frame_this_id, | |
1238 | dwarf2_frame_prev_register, | |
1239 | NULL, | |
1240 | dwarf2_frame_sniffer | |
1241 | }; | |
cfc14b3a | 1242 | |
4a4e5149 DJ |
1243 | /* Append the DWARF-2 frame unwinders to GDBARCH's list. */ |
1244 | ||
1245 | void | |
1246 | dwarf2_append_unwinders (struct gdbarch *gdbarch) | |
1247 | { | |
1248 | frame_unwind_append_unwinder (gdbarch, &dwarf2_frame_unwind); | |
1249 | frame_unwind_append_unwinder (gdbarch, &dwarf2_signal_frame_unwind); | |
cfc14b3a MK |
1250 | } |
1251 | \f | |
1252 | ||
1253 | /* There is no explicitly defined relationship between the CFA and the | |
1254 | location of frame's local variables and arguments/parameters. | |
1255 | Therefore, frame base methods on this page should probably only be | |
1256 | used as a last resort, just to avoid printing total garbage as a | |
1257 | response to the "info frame" command. */ | |
1258 | ||
1259 | static CORE_ADDR | |
4a4e5149 | 1260 | dwarf2_frame_base_address (struct frame_info *this_frame, void **this_cache) |
cfc14b3a MK |
1261 | { |
1262 | struct dwarf2_frame_cache *cache = | |
4a4e5149 | 1263 | dwarf2_frame_cache (this_frame, this_cache); |
cfc14b3a MK |
1264 | |
1265 | return cache->cfa; | |
1266 | } | |
1267 | ||
1268 | static const struct frame_base dwarf2_frame_base = | |
1269 | { | |
1270 | &dwarf2_frame_unwind, | |
1271 | dwarf2_frame_base_address, | |
1272 | dwarf2_frame_base_address, | |
1273 | dwarf2_frame_base_address | |
1274 | }; | |
1275 | ||
1276 | const struct frame_base * | |
4a4e5149 | 1277 | dwarf2_frame_base_sniffer (struct frame_info *this_frame) |
cfc14b3a | 1278 | { |
4a4e5149 | 1279 | CORE_ADDR block_addr = get_frame_address_in_block (this_frame); |
9a619af0 | 1280 | |
ac56253d | 1281 | if (dwarf2_frame_find_fde (&block_addr, NULL)) |
cfc14b3a MK |
1282 | return &dwarf2_frame_base; |
1283 | ||
1284 | return NULL; | |
1285 | } | |
e7802207 TT |
1286 | |
1287 | /* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from | |
1288 | the DWARF unwinder. This is used to implement | |
1289 | DW_OP_call_frame_cfa. */ | |
1290 | ||
1291 | CORE_ADDR | |
1292 | dwarf2_frame_cfa (struct frame_info *this_frame) | |
1293 | { | |
1294 | while (get_frame_type (this_frame) == INLINE_FRAME) | |
1295 | this_frame = get_prev_frame (this_frame); | |
1296 | /* This restriction could be lifted if other unwinders are known to | |
1297 | compute the frame base in a way compatible with the DWARF | |
1298 | unwinder. */ | |
1299 | if (! frame_unwinder_is (this_frame, &dwarf2_frame_unwind)) | |
1300 | error (_("can't compute CFA for this frame")); | |
1301 | return get_frame_base (this_frame); | |
1302 | } | |
cfc14b3a | 1303 | \f |
8f22cb90 | 1304 | const struct objfile_data *dwarf2_frame_objfile_data; |
0d0e1a63 | 1305 | |
cfc14b3a | 1306 | static unsigned int |
852483bc | 1307 | read_1_byte (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1308 | { |
852483bc | 1309 | return bfd_get_8 (abfd, buf); |
cfc14b3a MK |
1310 | } |
1311 | ||
1312 | static unsigned int | |
852483bc | 1313 | read_4_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1314 | { |
852483bc | 1315 | return bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1316 | } |
1317 | ||
1318 | static ULONGEST | |
852483bc | 1319 | read_8_bytes (bfd *abfd, gdb_byte *buf) |
cfc14b3a | 1320 | { |
852483bc | 1321 | return bfd_get_64 (abfd, buf); |
cfc14b3a MK |
1322 | } |
1323 | ||
1324 | static ULONGEST | |
852483bc | 1325 | read_unsigned_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1326 | { |
1327 | ULONGEST result; | |
1328 | unsigned int num_read; | |
1329 | int shift; | |
852483bc | 1330 | gdb_byte byte; |
cfc14b3a MK |
1331 | |
1332 | result = 0; | |
1333 | shift = 0; | |
1334 | num_read = 0; | |
1335 | ||
1336 | do | |
1337 | { | |
1338 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1339 | buf++; | |
1340 | num_read++; | |
1341 | result |= ((byte & 0x7f) << shift); | |
1342 | shift += 7; | |
1343 | } | |
1344 | while (byte & 0x80); | |
1345 | ||
1346 | *bytes_read_ptr = num_read; | |
1347 | ||
1348 | return result; | |
1349 | } | |
1350 | ||
1351 | static LONGEST | |
852483bc | 1352 | read_signed_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1353 | { |
1354 | LONGEST result; | |
1355 | int shift; | |
1356 | unsigned int num_read; | |
852483bc | 1357 | gdb_byte byte; |
cfc14b3a MK |
1358 | |
1359 | result = 0; | |
1360 | shift = 0; | |
1361 | num_read = 0; | |
1362 | ||
1363 | do | |
1364 | { | |
1365 | byte = bfd_get_8 (abfd, (bfd_byte *) buf); | |
1366 | buf++; | |
1367 | num_read++; | |
1368 | result |= ((byte & 0x7f) << shift); | |
1369 | shift += 7; | |
1370 | } | |
1371 | while (byte & 0x80); | |
1372 | ||
77e0b926 DJ |
1373 | if (shift < 8 * sizeof (result) && (byte & 0x40)) |
1374 | result |= -(((LONGEST)1) << shift); | |
cfc14b3a MK |
1375 | |
1376 | *bytes_read_ptr = num_read; | |
1377 | ||
1378 | return result; | |
1379 | } | |
1380 | ||
1381 | static ULONGEST | |
852483bc | 1382 | read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr) |
cfc14b3a MK |
1383 | { |
1384 | LONGEST result; | |
1385 | ||
852483bc | 1386 | result = bfd_get_32 (abfd, buf); |
cfc14b3a MK |
1387 | if (result == 0xffffffff) |
1388 | { | |
852483bc | 1389 | result = bfd_get_64 (abfd, buf + 4); |
cfc14b3a MK |
1390 | *bytes_read_ptr = 12; |
1391 | } | |
1392 | else | |
1393 | *bytes_read_ptr = 4; | |
1394 | ||
1395 | return result; | |
1396 | } | |
1397 | \f | |
1398 | ||
1399 | /* Pointer encoding helper functions. */ | |
1400 | ||
1401 | /* GCC supports exception handling based on DWARF2 CFI. However, for | |
1402 | technical reasons, it encodes addresses in its FDE's in a different | |
1403 | way. Several "pointer encodings" are supported. The encoding | |
1404 | that's used for a particular FDE is determined by the 'R' | |
1405 | augmentation in the associated CIE. The argument of this | |
1406 | augmentation is a single byte. | |
1407 | ||
1408 | The address can be encoded as 2 bytes, 4 bytes, 8 bytes, or as a | |
1409 | LEB128. This is encoded in bits 0, 1 and 2. Bit 3 encodes whether | |
1410 | the address is signed or unsigned. Bits 4, 5 and 6 encode how the | |
1411 | address should be interpreted (absolute, relative to the current | |
1412 | position in the FDE, ...). Bit 7, indicates that the address | |
1413 | should be dereferenced. */ | |
1414 | ||
852483bc | 1415 | static gdb_byte |
cfc14b3a MK |
1416 | encoding_for_size (unsigned int size) |
1417 | { | |
1418 | switch (size) | |
1419 | { | |
1420 | case 2: | |
1421 | return DW_EH_PE_udata2; | |
1422 | case 4: | |
1423 | return DW_EH_PE_udata4; | |
1424 | case 8: | |
1425 | return DW_EH_PE_udata8; | |
1426 | default: | |
e2e0b3e5 | 1427 | internal_error (__FILE__, __LINE__, _("Unsupported address size")); |
cfc14b3a MK |
1428 | } |
1429 | } | |
1430 | ||
cfc14b3a | 1431 | static CORE_ADDR |
852483bc | 1432 | read_encoded_value (struct comp_unit *unit, gdb_byte encoding, |
0d45f56e TT |
1433 | int ptr_len, const gdb_byte *buf, |
1434 | unsigned int *bytes_read_ptr, | |
ae0d2f24 | 1435 | CORE_ADDR func_base) |
cfc14b3a | 1436 | { |
68f6cf99 | 1437 | ptrdiff_t offset; |
cfc14b3a MK |
1438 | CORE_ADDR base; |
1439 | ||
1440 | /* GCC currently doesn't generate DW_EH_PE_indirect encodings for | |
1441 | FDE's. */ | |
1442 | if (encoding & DW_EH_PE_indirect) | |
1443 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 1444 | _("Unsupported encoding: DW_EH_PE_indirect")); |
cfc14b3a | 1445 | |
68f6cf99 MK |
1446 | *bytes_read_ptr = 0; |
1447 | ||
cfc14b3a MK |
1448 | switch (encoding & 0x70) |
1449 | { | |
1450 | case DW_EH_PE_absptr: | |
1451 | base = 0; | |
1452 | break; | |
1453 | case DW_EH_PE_pcrel: | |
f2fec864 | 1454 | base = bfd_get_section_vma (unit->abfd, unit->dwarf_frame_section); |
852483bc | 1455 | base += (buf - unit->dwarf_frame_buffer); |
cfc14b3a | 1456 | break; |
0912c7f2 MK |
1457 | case DW_EH_PE_datarel: |
1458 | base = unit->dbase; | |
1459 | break; | |
0fd85043 CV |
1460 | case DW_EH_PE_textrel: |
1461 | base = unit->tbase; | |
1462 | break; | |
03ac2a74 | 1463 | case DW_EH_PE_funcrel: |
ae0d2f24 | 1464 | base = func_base; |
03ac2a74 | 1465 | break; |
68f6cf99 MK |
1466 | case DW_EH_PE_aligned: |
1467 | base = 0; | |
852483bc | 1468 | offset = buf - unit->dwarf_frame_buffer; |
68f6cf99 MK |
1469 | if ((offset % ptr_len) != 0) |
1470 | { | |
1471 | *bytes_read_ptr = ptr_len - (offset % ptr_len); | |
1472 | buf += *bytes_read_ptr; | |
1473 | } | |
1474 | break; | |
cfc14b3a | 1475 | default: |
e2e0b3e5 | 1476 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1477 | } |
1478 | ||
b04de778 | 1479 | if ((encoding & 0x07) == 0x00) |
f2fec864 DJ |
1480 | { |
1481 | encoding |= encoding_for_size (ptr_len); | |
1482 | if (bfd_get_sign_extend_vma (unit->abfd)) | |
1483 | encoding |= DW_EH_PE_signed; | |
1484 | } | |
cfc14b3a MK |
1485 | |
1486 | switch (encoding & 0x0f) | |
1487 | { | |
a81b10ae MK |
1488 | case DW_EH_PE_uleb128: |
1489 | { | |
1490 | ULONGEST value; | |
0d45f56e | 1491 | const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
9a619af0 | 1492 | |
a7289609 | 1493 | *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1494 | return base + value; |
1495 | } | |
cfc14b3a | 1496 | case DW_EH_PE_udata2: |
68f6cf99 | 1497 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1498 | return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf)); |
1499 | case DW_EH_PE_udata4: | |
68f6cf99 | 1500 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1501 | return (base + bfd_get_32 (unit->abfd, (bfd_byte *) buf)); |
1502 | case DW_EH_PE_udata8: | |
68f6cf99 | 1503 | *bytes_read_ptr += 8; |
cfc14b3a | 1504 | return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf)); |
a81b10ae MK |
1505 | case DW_EH_PE_sleb128: |
1506 | { | |
1507 | LONGEST value; | |
0d45f56e | 1508 | const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7; |
9a619af0 | 1509 | |
a7289609 | 1510 | *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf; |
a81b10ae MK |
1511 | return base + value; |
1512 | } | |
cfc14b3a | 1513 | case DW_EH_PE_sdata2: |
68f6cf99 | 1514 | *bytes_read_ptr += 2; |
cfc14b3a MK |
1515 | return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf)); |
1516 | case DW_EH_PE_sdata4: | |
68f6cf99 | 1517 | *bytes_read_ptr += 4; |
cfc14b3a MK |
1518 | return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf)); |
1519 | case DW_EH_PE_sdata8: | |
68f6cf99 | 1520 | *bytes_read_ptr += 8; |
cfc14b3a MK |
1521 | return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf)); |
1522 | default: | |
e2e0b3e5 | 1523 | internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding")); |
cfc14b3a MK |
1524 | } |
1525 | } | |
1526 | \f | |
1527 | ||
b01c8410 PP |
1528 | static int |
1529 | bsearch_cie_cmp (const void *key, const void *element) | |
cfc14b3a | 1530 | { |
b01c8410 PP |
1531 | ULONGEST cie_pointer = *(ULONGEST *) key; |
1532 | struct dwarf2_cie *cie = *(struct dwarf2_cie **) element; | |
cfc14b3a | 1533 | |
b01c8410 PP |
1534 | if (cie_pointer == cie->cie_pointer) |
1535 | return 0; | |
cfc14b3a | 1536 | |
b01c8410 PP |
1537 | return (cie_pointer < cie->cie_pointer) ? -1 : 1; |
1538 | } | |
1539 | ||
1540 | /* Find CIE with the given CIE_POINTER in CIE_TABLE. */ | |
1541 | static struct dwarf2_cie * | |
1542 | find_cie (struct dwarf2_cie_table *cie_table, ULONGEST cie_pointer) | |
1543 | { | |
1544 | struct dwarf2_cie **p_cie; | |
cfc14b3a | 1545 | |
65a97ab3 PP |
1546 | /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to |
1547 | bsearch be non-NULL. */ | |
1548 | if (cie_table->entries == NULL) | |
1549 | { | |
1550 | gdb_assert (cie_table->num_entries == 0); | |
1551 | return NULL; | |
1552 | } | |
1553 | ||
b01c8410 PP |
1554 | p_cie = bsearch (&cie_pointer, cie_table->entries, cie_table->num_entries, |
1555 | sizeof (cie_table->entries[0]), bsearch_cie_cmp); | |
1556 | if (p_cie != NULL) | |
1557 | return *p_cie; | |
cfc14b3a MK |
1558 | return NULL; |
1559 | } | |
1560 | ||
b01c8410 | 1561 | /* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */ |
cfc14b3a | 1562 | static void |
b01c8410 | 1563 | add_cie (struct dwarf2_cie_table *cie_table, struct dwarf2_cie *cie) |
cfc14b3a | 1564 | { |
b01c8410 PP |
1565 | const int n = cie_table->num_entries; |
1566 | ||
1567 | gdb_assert (n < 1 | |
1568 | || cie_table->entries[n - 1]->cie_pointer < cie->cie_pointer); | |
1569 | ||
1570 | cie_table->entries = | |
1571 | xrealloc (cie_table->entries, (n + 1) * sizeof (cie_table->entries[0])); | |
1572 | cie_table->entries[n] = cie; | |
1573 | cie_table->num_entries = n + 1; | |
1574 | } | |
1575 | ||
1576 | static int | |
1577 | bsearch_fde_cmp (const void *key, const void *element) | |
1578 | { | |
1579 | CORE_ADDR seek_pc = *(CORE_ADDR *) key; | |
1580 | struct dwarf2_fde *fde = *(struct dwarf2_fde **) element; | |
9a619af0 | 1581 | |
b01c8410 PP |
1582 | if (seek_pc < fde->initial_location) |
1583 | return -1; | |
1584 | if (seek_pc < fde->initial_location + fde->address_range) | |
1585 | return 0; | |
1586 | return 1; | |
cfc14b3a MK |
1587 | } |
1588 | ||
1589 | /* Find the FDE for *PC. Return a pointer to the FDE, and store the | |
1590 | inital location associated with it into *PC. */ | |
1591 | ||
1592 | static struct dwarf2_fde * | |
ac56253d | 1593 | dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset) |
cfc14b3a MK |
1594 | { |
1595 | struct objfile *objfile; | |
1596 | ||
1597 | ALL_OBJFILES (objfile) | |
1598 | { | |
b01c8410 PP |
1599 | struct dwarf2_fde_table *fde_table; |
1600 | struct dwarf2_fde **p_fde; | |
cfc14b3a | 1601 | CORE_ADDR offset; |
b01c8410 | 1602 | CORE_ADDR seek_pc; |
cfc14b3a | 1603 | |
b01c8410 PP |
1604 | fde_table = objfile_data (objfile, dwarf2_frame_objfile_data); |
1605 | if (fde_table == NULL) | |
be391dca TT |
1606 | { |
1607 | dwarf2_build_frame_info (objfile); | |
1608 | fde_table = objfile_data (objfile, dwarf2_frame_objfile_data); | |
1609 | } | |
1610 | gdb_assert (fde_table != NULL); | |
1611 | ||
1612 | if (fde_table->num_entries == 0) | |
4ae9ee8e DJ |
1613 | continue; |
1614 | ||
1615 | gdb_assert (objfile->section_offsets); | |
1616 | offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile)); | |
1617 | ||
b01c8410 PP |
1618 | gdb_assert (fde_table->num_entries > 0); |
1619 | if (*pc < offset + fde_table->entries[0]->initial_location) | |
1620 | continue; | |
1621 | ||
1622 | seek_pc = *pc - offset; | |
1623 | p_fde = bsearch (&seek_pc, fde_table->entries, fde_table->num_entries, | |
1624 | sizeof (fde_table->entries[0]), bsearch_fde_cmp); | |
1625 | if (p_fde != NULL) | |
1626 | { | |
1627 | *pc = (*p_fde)->initial_location + offset; | |
ac56253d TT |
1628 | if (out_offset) |
1629 | *out_offset = offset; | |
b01c8410 PP |
1630 | return *p_fde; |
1631 | } | |
cfc14b3a | 1632 | } |
cfc14b3a MK |
1633 | return NULL; |
1634 | } | |
1635 | ||
b01c8410 | 1636 | /* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */ |
cfc14b3a | 1637 | static void |
b01c8410 | 1638 | add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde) |
cfc14b3a | 1639 | { |
b01c8410 PP |
1640 | if (fde->address_range == 0) |
1641 | /* Discard useless FDEs. */ | |
1642 | return; | |
1643 | ||
1644 | fde_table->num_entries += 1; | |
1645 | fde_table->entries = | |
1646 | xrealloc (fde_table->entries, | |
1647 | fde_table->num_entries * sizeof (fde_table->entries[0])); | |
1648 | fde_table->entries[fde_table->num_entries - 1] = fde; | |
cfc14b3a MK |
1649 | } |
1650 | ||
1651 | #ifdef CC_HAS_LONG_LONG | |
1652 | #define DW64_CIE_ID 0xffffffffffffffffULL | |
1653 | #else | |
1654 | #define DW64_CIE_ID ~0 | |
1655 | #endif | |
1656 | ||
852483bc | 1657 | static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start, |
b01c8410 PP |
1658 | int eh_frame_p, |
1659 | struct dwarf2_cie_table *cie_table, | |
1660 | struct dwarf2_fde_table *fde_table); | |
cfc14b3a | 1661 | |
6896c0c7 RH |
1662 | /* Decode the next CIE or FDE. Return NULL if invalid input, otherwise |
1663 | the next byte to be processed. */ | |
852483bc | 1664 | static gdb_byte * |
b01c8410 PP |
1665 | decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1666 | struct dwarf2_cie_table *cie_table, | |
1667 | struct dwarf2_fde_table *fde_table) | |
cfc14b3a | 1668 | { |
5e2b427d | 1669 | struct gdbarch *gdbarch = get_objfile_arch (unit->objfile); |
852483bc | 1670 | gdb_byte *buf, *end; |
cfc14b3a MK |
1671 | LONGEST length; |
1672 | unsigned int bytes_read; | |
6896c0c7 RH |
1673 | int dwarf64_p; |
1674 | ULONGEST cie_id; | |
cfc14b3a | 1675 | ULONGEST cie_pointer; |
cfc14b3a | 1676 | |
6896c0c7 | 1677 | buf = start; |
cfc14b3a MK |
1678 | length = read_initial_length (unit->abfd, buf, &bytes_read); |
1679 | buf += bytes_read; | |
1680 | end = buf + length; | |
1681 | ||
6896c0c7 RH |
1682 | /* Are we still within the section? */ |
1683 | if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
1684 | return NULL; | |
1685 | ||
cfc14b3a MK |
1686 | if (length == 0) |
1687 | return end; | |
1688 | ||
6896c0c7 RH |
1689 | /* Distinguish between 32 and 64-bit encoded frame info. */ |
1690 | dwarf64_p = (bytes_read == 12); | |
cfc14b3a | 1691 | |
6896c0c7 | 1692 | /* In a .eh_frame section, zero is used to distinguish CIEs from FDEs. */ |
cfc14b3a MK |
1693 | if (eh_frame_p) |
1694 | cie_id = 0; | |
1695 | else if (dwarf64_p) | |
1696 | cie_id = DW64_CIE_ID; | |
6896c0c7 RH |
1697 | else |
1698 | cie_id = DW_CIE_ID; | |
cfc14b3a MK |
1699 | |
1700 | if (dwarf64_p) | |
1701 | { | |
1702 | cie_pointer = read_8_bytes (unit->abfd, buf); | |
1703 | buf += 8; | |
1704 | } | |
1705 | else | |
1706 | { | |
1707 | cie_pointer = read_4_bytes (unit->abfd, buf); | |
1708 | buf += 4; | |
1709 | } | |
1710 | ||
1711 | if (cie_pointer == cie_id) | |
1712 | { | |
1713 | /* This is a CIE. */ | |
1714 | struct dwarf2_cie *cie; | |
1715 | char *augmentation; | |
28ba0b33 | 1716 | unsigned int cie_version; |
cfc14b3a MK |
1717 | |
1718 | /* Record the offset into the .debug_frame section of this CIE. */ | |
1719 | cie_pointer = start - unit->dwarf_frame_buffer; | |
1720 | ||
1721 | /* Check whether we've already read it. */ | |
b01c8410 | 1722 | if (find_cie (cie_table, cie_pointer)) |
cfc14b3a MK |
1723 | return end; |
1724 | ||
1725 | cie = (struct dwarf2_cie *) | |
8b92e4d5 | 1726 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a MK |
1727 | sizeof (struct dwarf2_cie)); |
1728 | cie->initial_instructions = NULL; | |
1729 | cie->cie_pointer = cie_pointer; | |
1730 | ||
1731 | /* The encoding for FDE's in a normal .debug_frame section | |
32b05c07 MK |
1732 | depends on the target address size. */ |
1733 | cie->encoding = DW_EH_PE_absptr; | |
cfc14b3a | 1734 | |
ae0d2f24 UW |
1735 | /* The target address size. For .eh_frame FDEs this is considered |
1736 | equal to the size of a target pointer. For .dwarf_frame FDEs, | |
1737 | this is supposed to be the target address size from the associated | |
1738 | CU header. FIXME: We do not have a good way to determine the | |
1739 | latter. Always use the target pointer size for now. */ | |
5e2b427d | 1740 | cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
ae0d2f24 | 1741 | |
56c987f6 AO |
1742 | /* We'll determine the final value later, but we need to |
1743 | initialize it conservatively. */ | |
1744 | cie->signal_frame = 0; | |
1745 | ||
cfc14b3a | 1746 | /* Check version number. */ |
28ba0b33 | 1747 | cie_version = read_1_byte (unit->abfd, buf); |
2dc7f7b3 | 1748 | if (cie_version != 1 && cie_version != 3 && cie_version != 4) |
6896c0c7 | 1749 | return NULL; |
303b6f5d | 1750 | cie->version = cie_version; |
cfc14b3a MK |
1751 | buf += 1; |
1752 | ||
1753 | /* Interpret the interesting bits of the augmentation. */ | |
303b6f5d | 1754 | cie->augmentation = augmentation = (char *) buf; |
852483bc | 1755 | buf += (strlen (augmentation) + 1); |
cfc14b3a | 1756 | |
303b6f5d DJ |
1757 | /* Ignore armcc augmentations. We only use them for quirks, |
1758 | and that doesn't happen until later. */ | |
1759 | if (strncmp (augmentation, "armcc", 5) == 0) | |
1760 | augmentation += strlen (augmentation); | |
1761 | ||
cfc14b3a MK |
1762 | /* The GCC 2.x "eh" augmentation has a pointer immediately |
1763 | following the augmentation string, so it must be handled | |
1764 | first. */ | |
1765 | if (augmentation[0] == 'e' && augmentation[1] == 'h') | |
1766 | { | |
1767 | /* Skip. */ | |
5e2b427d | 1768 | buf += gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; |
cfc14b3a MK |
1769 | augmentation += 2; |
1770 | } | |
1771 | ||
2dc7f7b3 TT |
1772 | if (cie->version >= 4) |
1773 | { | |
1774 | /* FIXME: check that this is the same as from the CU header. */ | |
1775 | cie->addr_size = read_1_byte (unit->abfd, buf); | |
1776 | ++buf; | |
1777 | cie->segment_size = read_1_byte (unit->abfd, buf); | |
1778 | ++buf; | |
1779 | } | |
1780 | else | |
1781 | { | |
1782 | cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; | |
1783 | cie->segment_size = 0; | |
1784 | } | |
1785 | ||
cfc14b3a MK |
1786 | cie->code_alignment_factor = |
1787 | read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1788 | buf += bytes_read; | |
1789 | ||
1790 | cie->data_alignment_factor = | |
1791 | read_signed_leb128 (unit->abfd, buf, &bytes_read); | |
1792 | buf += bytes_read; | |
1793 | ||
28ba0b33 PB |
1794 | if (cie_version == 1) |
1795 | { | |
1796 | cie->return_address_register = read_1_byte (unit->abfd, buf); | |
1797 | bytes_read = 1; | |
1798 | } | |
1799 | else | |
1800 | cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf, | |
1801 | &bytes_read); | |
4fc771b8 | 1802 | cie->return_address_register |
5e2b427d | 1803 | = dwarf2_frame_adjust_regnum (gdbarch, |
4fc771b8 DJ |
1804 | cie->return_address_register, |
1805 | eh_frame_p); | |
4bf8967c | 1806 | |
28ba0b33 | 1807 | buf += bytes_read; |
cfc14b3a | 1808 | |
7131cb6e RH |
1809 | cie->saw_z_augmentation = (*augmentation == 'z'); |
1810 | if (cie->saw_z_augmentation) | |
cfc14b3a MK |
1811 | { |
1812 | ULONGEST length; | |
1813 | ||
1814 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1815 | buf += bytes_read; | |
6896c0c7 RH |
1816 | if (buf > end) |
1817 | return NULL; | |
cfc14b3a MK |
1818 | cie->initial_instructions = buf + length; |
1819 | augmentation++; | |
1820 | } | |
1821 | ||
1822 | while (*augmentation) | |
1823 | { | |
1824 | /* "L" indicates a byte showing how the LSDA pointer is encoded. */ | |
1825 | if (*augmentation == 'L') | |
1826 | { | |
1827 | /* Skip. */ | |
1828 | buf++; | |
1829 | augmentation++; | |
1830 | } | |
1831 | ||
1832 | /* "R" indicates a byte indicating how FDE addresses are encoded. */ | |
1833 | else if (*augmentation == 'R') | |
1834 | { | |
1835 | cie->encoding = *buf++; | |
1836 | augmentation++; | |
1837 | } | |
1838 | ||
1839 | /* "P" indicates a personality routine in the CIE augmentation. */ | |
1840 | else if (*augmentation == 'P') | |
1841 | { | |
1234d960 | 1842 | /* Skip. Avoid indirection since we throw away the result. */ |
852483bc | 1843 | gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect; |
ae0d2f24 UW |
1844 | read_encoded_value (unit, encoding, cie->addr_size, |
1845 | buf, &bytes_read, 0); | |
f724bf08 | 1846 | buf += bytes_read; |
cfc14b3a MK |
1847 | augmentation++; |
1848 | } | |
1849 | ||
56c987f6 AO |
1850 | /* "S" indicates a signal frame, such that the return |
1851 | address must not be decremented to locate the call frame | |
1852 | info for the previous frame; it might even be the first | |
1853 | instruction of a function, so decrementing it would take | |
1854 | us to a different function. */ | |
1855 | else if (*augmentation == 'S') | |
1856 | { | |
1857 | cie->signal_frame = 1; | |
1858 | augmentation++; | |
1859 | } | |
1860 | ||
3e9a2e52 DJ |
1861 | /* Otherwise we have an unknown augmentation. Assume that either |
1862 | there is no augmentation data, or we saw a 'z' prefix. */ | |
cfc14b3a MK |
1863 | else |
1864 | { | |
3e9a2e52 DJ |
1865 | if (cie->initial_instructions) |
1866 | buf = cie->initial_instructions; | |
cfc14b3a MK |
1867 | break; |
1868 | } | |
1869 | } | |
1870 | ||
1871 | cie->initial_instructions = buf; | |
1872 | cie->end = end; | |
b01c8410 | 1873 | cie->unit = unit; |
cfc14b3a | 1874 | |
b01c8410 | 1875 | add_cie (cie_table, cie); |
cfc14b3a MK |
1876 | } |
1877 | else | |
1878 | { | |
1879 | /* This is a FDE. */ | |
1880 | struct dwarf2_fde *fde; | |
1881 | ||
6896c0c7 RH |
1882 | /* In an .eh_frame section, the CIE pointer is the delta between the |
1883 | address within the FDE where the CIE pointer is stored and the | |
1884 | address of the CIE. Convert it to an offset into the .eh_frame | |
1885 | section. */ | |
cfc14b3a MK |
1886 | if (eh_frame_p) |
1887 | { | |
cfc14b3a MK |
1888 | cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer; |
1889 | cie_pointer -= (dwarf64_p ? 8 : 4); | |
1890 | } | |
1891 | ||
6896c0c7 RH |
1892 | /* In either case, validate the result is still within the section. */ |
1893 | if (cie_pointer >= unit->dwarf_frame_size) | |
1894 | return NULL; | |
1895 | ||
cfc14b3a | 1896 | fde = (struct dwarf2_fde *) |
8b92e4d5 | 1897 | obstack_alloc (&unit->objfile->objfile_obstack, |
cfc14b3a | 1898 | sizeof (struct dwarf2_fde)); |
b01c8410 | 1899 | fde->cie = find_cie (cie_table, cie_pointer); |
cfc14b3a MK |
1900 | if (fde->cie == NULL) |
1901 | { | |
1902 | decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer, | |
b01c8410 PP |
1903 | eh_frame_p, cie_table, fde_table); |
1904 | fde->cie = find_cie (cie_table, cie_pointer); | |
cfc14b3a MK |
1905 | } |
1906 | ||
1907 | gdb_assert (fde->cie != NULL); | |
1908 | ||
1909 | fde->initial_location = | |
ae0d2f24 UW |
1910 | read_encoded_value (unit, fde->cie->encoding, fde->cie->addr_size, |
1911 | buf, &bytes_read, 0); | |
cfc14b3a MK |
1912 | buf += bytes_read; |
1913 | ||
1914 | fde->address_range = | |
ae0d2f24 UW |
1915 | read_encoded_value (unit, fde->cie->encoding & 0x0f, |
1916 | fde->cie->addr_size, buf, &bytes_read, 0); | |
cfc14b3a MK |
1917 | buf += bytes_read; |
1918 | ||
7131cb6e RH |
1919 | /* A 'z' augmentation in the CIE implies the presence of an |
1920 | augmentation field in the FDE as well. The only thing known | |
1921 | to be in here at present is the LSDA entry for EH. So we | |
1922 | can skip the whole thing. */ | |
1923 | if (fde->cie->saw_z_augmentation) | |
1924 | { | |
1925 | ULONGEST length; | |
1926 | ||
1927 | length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read); | |
1928 | buf += bytes_read + length; | |
6896c0c7 RH |
1929 | if (buf > end) |
1930 | return NULL; | |
7131cb6e RH |
1931 | } |
1932 | ||
cfc14b3a MK |
1933 | fde->instructions = buf; |
1934 | fde->end = end; | |
1935 | ||
4bf8967c AS |
1936 | fde->eh_frame_p = eh_frame_p; |
1937 | ||
b01c8410 | 1938 | add_fde (fde_table, fde); |
cfc14b3a MK |
1939 | } |
1940 | ||
1941 | return end; | |
1942 | } | |
6896c0c7 RH |
1943 | |
1944 | /* Read a CIE or FDE in BUF and decode it. */ | |
852483bc | 1945 | static gdb_byte * |
b01c8410 PP |
1946 | decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p, |
1947 | struct dwarf2_cie_table *cie_table, | |
1948 | struct dwarf2_fde_table *fde_table) | |
6896c0c7 RH |
1949 | { |
1950 | enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE; | |
852483bc | 1951 | gdb_byte *ret; |
6896c0c7 RH |
1952 | ptrdiff_t start_offset; |
1953 | ||
1954 | while (1) | |
1955 | { | |
b01c8410 PP |
1956 | ret = decode_frame_entry_1 (unit, start, eh_frame_p, |
1957 | cie_table, fde_table); | |
6896c0c7 RH |
1958 | if (ret != NULL) |
1959 | break; | |
1960 | ||
1961 | /* We have corrupt input data of some form. */ | |
1962 | ||
1963 | /* ??? Try, weakly, to work around compiler/assembler/linker bugs | |
1964 | and mismatches wrt padding and alignment of debug sections. */ | |
1965 | /* Note that there is no requirement in the standard for any | |
1966 | alignment at all in the frame unwind sections. Testing for | |
1967 | alignment before trying to interpret data would be incorrect. | |
1968 | ||
1969 | However, GCC traditionally arranged for frame sections to be | |
1970 | sized such that the FDE length and CIE fields happen to be | |
1971 | aligned (in theory, for performance). This, unfortunately, | |
1972 | was done with .align directives, which had the side effect of | |
1973 | forcing the section to be aligned by the linker. | |
1974 | ||
1975 | This becomes a problem when you have some other producer that | |
1976 | creates frame sections that are not as strictly aligned. That | |
1977 | produces a hole in the frame info that gets filled by the | |
1978 | linker with zeros. | |
1979 | ||
1980 | The GCC behaviour is arguably a bug, but it's effectively now | |
1981 | part of the ABI, so we're now stuck with it, at least at the | |
1982 | object file level. A smart linker may decide, in the process | |
1983 | of compressing duplicate CIE information, that it can rewrite | |
1984 | the entire output section without this extra padding. */ | |
1985 | ||
1986 | start_offset = start - unit->dwarf_frame_buffer; | |
1987 | if (workaround < ALIGN4 && (start_offset & 3) != 0) | |
1988 | { | |
1989 | start += 4 - (start_offset & 3); | |
1990 | workaround = ALIGN4; | |
1991 | continue; | |
1992 | } | |
1993 | if (workaround < ALIGN8 && (start_offset & 7) != 0) | |
1994 | { | |
1995 | start += 8 - (start_offset & 7); | |
1996 | workaround = ALIGN8; | |
1997 | continue; | |
1998 | } | |
1999 | ||
2000 | /* Nothing left to try. Arrange to return as if we've consumed | |
2001 | the entire input section. Hopefully we'll get valid info from | |
2002 | the other of .debug_frame/.eh_frame. */ | |
2003 | workaround = FAIL; | |
2004 | ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size; | |
2005 | break; | |
2006 | } | |
2007 | ||
2008 | switch (workaround) | |
2009 | { | |
2010 | case NONE: | |
2011 | break; | |
2012 | ||
2013 | case ALIGN4: | |
2014 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2015 | _("Corrupt data in %s:%s; align 4 workaround apparently succeeded"), |
6896c0c7 RH |
2016 | unit->dwarf_frame_section->owner->filename, |
2017 | unit->dwarf_frame_section->name); | |
2018 | break; | |
2019 | ||
2020 | case ALIGN8: | |
2021 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2022 | _("Corrupt data in %s:%s; align 8 workaround apparently succeeded"), |
6896c0c7 RH |
2023 | unit->dwarf_frame_section->owner->filename, |
2024 | unit->dwarf_frame_section->name); | |
2025 | break; | |
2026 | ||
2027 | default: | |
2028 | complaint (&symfile_complaints, | |
e2e0b3e5 | 2029 | _("Corrupt data in %s:%s"), |
6896c0c7 RH |
2030 | unit->dwarf_frame_section->owner->filename, |
2031 | unit->dwarf_frame_section->name); | |
2032 | break; | |
2033 | } | |
2034 | ||
2035 | return ret; | |
2036 | } | |
cfc14b3a MK |
2037 | \f |
2038 | ||
cfc14b3a | 2039 | /* Imported from dwarf2read.c. */ |
dce234bc PP |
2040 | extern void dwarf2_get_section_info (struct objfile *, const char *, asection **, |
2041 | gdb_byte **, bfd_size_type *); | |
cfc14b3a | 2042 | |
b01c8410 PP |
2043 | static int |
2044 | qsort_fde_cmp (const void *a, const void *b) | |
2045 | { | |
2046 | struct dwarf2_fde *aa = *(struct dwarf2_fde **)a; | |
2047 | struct dwarf2_fde *bb = *(struct dwarf2_fde **)b; | |
e5af178f | 2048 | |
b01c8410 | 2049 | if (aa->initial_location == bb->initial_location) |
e5af178f PP |
2050 | { |
2051 | if (aa->address_range != bb->address_range | |
2052 | && aa->eh_frame_p == 0 && bb->eh_frame_p == 0) | |
2053 | /* Linker bug, e.g. gold/10400. | |
2054 | Work around it by keeping stable sort order. */ | |
2055 | return (a < b) ? -1 : 1; | |
2056 | else | |
2057 | /* Put eh_frame entries after debug_frame ones. */ | |
2058 | return aa->eh_frame_p - bb->eh_frame_p; | |
2059 | } | |
b01c8410 PP |
2060 | |
2061 | return (aa->initial_location < bb->initial_location) ? -1 : 1; | |
2062 | } | |
2063 | ||
cfc14b3a MK |
2064 | void |
2065 | dwarf2_build_frame_info (struct objfile *objfile) | |
2066 | { | |
ae0d2f24 | 2067 | struct comp_unit *unit; |
852483bc | 2068 | gdb_byte *frame_ptr; |
b01c8410 PP |
2069 | struct dwarf2_cie_table cie_table; |
2070 | struct dwarf2_fde_table fde_table; | |
be391dca | 2071 | struct dwarf2_fde_table *fde_table2; |
b01c8410 PP |
2072 | |
2073 | cie_table.num_entries = 0; | |
2074 | cie_table.entries = NULL; | |
2075 | ||
2076 | fde_table.num_entries = 0; | |
2077 | fde_table.entries = NULL; | |
cfc14b3a MK |
2078 | |
2079 | /* Build a minimal decoding of the DWARF2 compilation unit. */ | |
ae0d2f24 UW |
2080 | unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack, |
2081 | sizeof (struct comp_unit)); | |
2082 | unit->abfd = objfile->obfd; | |
2083 | unit->objfile = objfile; | |
2084 | unit->dbase = 0; | |
2085 | unit->tbase = 0; | |
cfc14b3a | 2086 | |
dce234bc PP |
2087 | dwarf2_get_section_info (objfile, ".eh_frame", |
2088 | &unit->dwarf_frame_section, | |
2089 | &unit->dwarf_frame_buffer, | |
2090 | &unit->dwarf_frame_size); | |
2091 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2092 | { |
0fd85043 | 2093 | asection *got, *txt; |
0912c7f2 | 2094 | |
0912c7f2 | 2095 | /* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base |
37b517aa MK |
2096 | that is used for the i386/amd64 target, which currently is |
2097 | the only target in GCC that supports/uses the | |
2098 | DW_EH_PE_datarel encoding. */ | |
ae0d2f24 | 2099 | got = bfd_get_section_by_name (unit->abfd, ".got"); |
0912c7f2 | 2100 | if (got) |
ae0d2f24 | 2101 | unit->dbase = got->vma; |
0912c7f2 | 2102 | |
22c7ba1a MK |
2103 | /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64 |
2104 | so far. */ | |
ae0d2f24 | 2105 | txt = bfd_get_section_by_name (unit->abfd, ".text"); |
0fd85043 | 2106 | if (txt) |
ae0d2f24 | 2107 | unit->tbase = txt->vma; |
0fd85043 | 2108 | |
ae0d2f24 UW |
2109 | frame_ptr = unit->dwarf_frame_buffer; |
2110 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2111 | frame_ptr = decode_frame_entry (unit, frame_ptr, 1, |
2112 | &cie_table, &fde_table); | |
2113 | ||
2114 | if (cie_table.num_entries != 0) | |
2115 | { | |
2116 | /* Reinit cie_table: debug_frame has different CIEs. */ | |
2117 | xfree (cie_table.entries); | |
2118 | cie_table.num_entries = 0; | |
2119 | cie_table.entries = NULL; | |
2120 | } | |
cfc14b3a MK |
2121 | } |
2122 | ||
dce234bc PP |
2123 | dwarf2_get_section_info (objfile, ".debug_frame", |
2124 | &unit->dwarf_frame_section, | |
2125 | &unit->dwarf_frame_buffer, | |
2126 | &unit->dwarf_frame_size); | |
2127 | if (unit->dwarf_frame_size) | |
cfc14b3a | 2128 | { |
ae0d2f24 UW |
2129 | frame_ptr = unit->dwarf_frame_buffer; |
2130 | while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) | |
b01c8410 PP |
2131 | frame_ptr = decode_frame_entry (unit, frame_ptr, 0, |
2132 | &cie_table, &fde_table); | |
2133 | } | |
2134 | ||
2135 | /* Discard the cie_table, it is no longer needed. */ | |
2136 | if (cie_table.num_entries != 0) | |
2137 | { | |
2138 | xfree (cie_table.entries); | |
2139 | cie_table.entries = NULL; /* Paranoia. */ | |
2140 | cie_table.num_entries = 0; /* Paranoia. */ | |
2141 | } | |
2142 | ||
be391dca TT |
2143 | /* Copy fde_table to obstack: it is needed at runtime. */ |
2144 | fde_table2 = (struct dwarf2_fde_table *) | |
2145 | obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2)); | |
2146 | ||
2147 | if (fde_table.num_entries == 0) | |
2148 | { | |
2149 | fde_table2->entries = NULL; | |
2150 | fde_table2->num_entries = 0; | |
2151 | } | |
2152 | else | |
b01c8410 | 2153 | { |
875cdfbb PA |
2154 | struct dwarf2_fde *fde_prev = NULL; |
2155 | struct dwarf2_fde *first_non_zero_fde = NULL; | |
2156 | int i; | |
b01c8410 PP |
2157 | |
2158 | /* Prepare FDE table for lookups. */ | |
2159 | qsort (fde_table.entries, fde_table.num_entries, | |
2160 | sizeof (fde_table.entries[0]), qsort_fde_cmp); | |
2161 | ||
875cdfbb PA |
2162 | /* Check for leftovers from --gc-sections. The GNU linker sets |
2163 | the relevant symbols to zero, but doesn't zero the FDE *end* | |
2164 | ranges because there's no relocation there. It's (offset, | |
2165 | length), not (start, end). On targets where address zero is | |
2166 | just another valid address this can be a problem, since the | |
2167 | FDEs appear to be non-empty in the output --- we could pick | |
2168 | out the wrong FDE. To work around this, when overlaps are | |
2169 | detected, we prefer FDEs that do not start at zero. | |
2170 | ||
2171 | Start by finding the first FDE with non-zero start. Below | |
2172 | we'll discard all FDEs that start at zero and overlap this | |
2173 | one. */ | |
2174 | for (i = 0; i < fde_table.num_entries; i++) | |
2175 | { | |
2176 | struct dwarf2_fde *fde = fde_table.entries[i]; | |
b01c8410 | 2177 | |
875cdfbb PA |
2178 | if (fde->initial_location != 0) |
2179 | { | |
2180 | first_non_zero_fde = fde; | |
2181 | break; | |
2182 | } | |
2183 | } | |
2184 | ||
2185 | /* Since we'll be doing bsearch, squeeze out identical (except | |
2186 | for eh_frame_p) fde entries so bsearch result is predictable. | |
2187 | Also discard leftovers from --gc-sections. */ | |
be391dca | 2188 | fde_table2->num_entries = 0; |
875cdfbb PA |
2189 | for (i = 0; i < fde_table.num_entries; i++) |
2190 | { | |
2191 | struct dwarf2_fde *fde = fde_table.entries[i]; | |
2192 | ||
2193 | if (fde->initial_location == 0 | |
2194 | && first_non_zero_fde != NULL | |
2195 | && (first_non_zero_fde->initial_location | |
2196 | < fde->initial_location + fde->address_range)) | |
2197 | continue; | |
2198 | ||
2199 | if (fde_prev != NULL | |
2200 | && fde_prev->initial_location == fde->initial_location) | |
2201 | continue; | |
2202 | ||
2203 | obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i], | |
2204 | sizeof (fde_table.entries[0])); | |
2205 | ++fde_table2->num_entries; | |
2206 | fde_prev = fde; | |
2207 | } | |
b01c8410 | 2208 | fde_table2->entries = obstack_finish (&objfile->objfile_obstack); |
b01c8410 PP |
2209 | |
2210 | /* Discard the original fde_table. */ | |
2211 | xfree (fde_table.entries); | |
cfc14b3a | 2212 | } |
be391dca TT |
2213 | |
2214 | set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2); | |
cfc14b3a | 2215 | } |
0d0e1a63 MK |
2216 | |
2217 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
2218 | void _initialize_dwarf2_frame (void); | |
2219 | ||
2220 | void | |
2221 | _initialize_dwarf2_frame (void) | |
2222 | { | |
030f20e1 | 2223 | dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init); |
8f22cb90 | 2224 | dwarf2_frame_objfile_data = register_objfile_data (); |
0d0e1a63 | 2225 | } |