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