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1 | /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger. | |
2 | Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 | |
3 | Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "defs.h" | |
23 | #include "frame.h" | |
24 | #include "inferior.h" | |
25 | #include "symtab.h" | |
26 | #include "value.h" | |
27 | #include "gdbcmd.h" | |
28 | #include "gdbcore.h" | |
29 | #include "dis-asm.h" | |
30 | #include "symfile.h" | |
31 | #include "objfiles.h" | |
32 | #include "gdb_string.h" | |
33 | #include "linespec.h" | |
34 | #include "regcache.h" | |
35 | #include "doublest.h" | |
36 | #include "arch-utils.h" | |
37 | #include "osabi.h" | |
38 | #include "block.h" | |
39 | ||
40 | #include "elf-bfd.h" | |
41 | ||
42 | #include "alpha-tdep.h" | |
43 | ||
44 | static gdbarch_init_ftype alpha_gdbarch_init; | |
45 | ||
46 | static gdbarch_register_name_ftype alpha_register_name; | |
47 | static gdbarch_register_raw_size_ftype alpha_register_raw_size; | |
48 | static gdbarch_register_virtual_size_ftype alpha_register_virtual_size; | |
49 | static gdbarch_register_virtual_type_ftype alpha_register_virtual_type; | |
50 | static gdbarch_register_byte_ftype alpha_register_byte; | |
51 | static gdbarch_cannot_fetch_register_ftype alpha_cannot_fetch_register; | |
52 | static gdbarch_cannot_store_register_ftype alpha_cannot_store_register; | |
53 | static gdbarch_register_convertible_ftype alpha_register_convertible; | |
54 | static gdbarch_register_convert_to_virtual_ftype | |
55 | alpha_register_convert_to_virtual; | |
56 | static gdbarch_register_convert_to_raw_ftype alpha_register_convert_to_raw; | |
57 | static gdbarch_deprecated_extract_return_value_ftype alpha_extract_return_value; | |
58 | static gdbarch_deprecated_extract_struct_value_address_ftype | |
59 | alpha_extract_struct_value_address; | |
60 | static gdbarch_use_struct_convention_ftype alpha_use_struct_convention; | |
61 | ||
62 | static gdbarch_breakpoint_from_pc_ftype alpha_breakpoint_from_pc; | |
63 | ||
64 | static gdbarch_frame_args_address_ftype alpha_frame_args_address; | |
65 | static gdbarch_frame_locals_address_ftype alpha_frame_locals_address; | |
66 | ||
67 | static gdbarch_skip_prologue_ftype alpha_skip_prologue; | |
68 | static gdbarch_saved_pc_after_call_ftype alpha_saved_pc_after_call; | |
69 | ||
70 | static gdbarch_fix_call_dummy_ftype alpha_fix_call_dummy; | |
71 | ||
72 | static gdbarch_get_longjmp_target_ftype alpha_get_longjmp_target; | |
73 | ||
74 | struct frame_extra_info | |
75 | { | |
76 | alpha_extra_func_info_t proc_desc; | |
77 | int localoff; | |
78 | int pc_reg; | |
79 | }; | |
80 | ||
81 | /* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */ | |
82 | ||
83 | /* Prototypes for local functions. */ | |
84 | ||
85 | static void alpha_find_saved_regs (struct frame_info *); | |
86 | ||
87 | static alpha_extra_func_info_t push_sigtramp_desc (CORE_ADDR low_addr); | |
88 | ||
89 | static CORE_ADDR read_next_frame_reg (struct frame_info *, int); | |
90 | ||
91 | static CORE_ADDR heuristic_proc_start (CORE_ADDR); | |
92 | ||
93 | static alpha_extra_func_info_t heuristic_proc_desc (CORE_ADDR, | |
94 | CORE_ADDR, | |
95 | struct frame_info *); | |
96 | ||
97 | static alpha_extra_func_info_t find_proc_desc (CORE_ADDR, | |
98 | struct frame_info *); | |
99 | ||
100 | #if 0 | |
101 | static int alpha_in_lenient_prologue (CORE_ADDR, CORE_ADDR); | |
102 | #endif | |
103 | ||
104 | static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element *); | |
105 | ||
106 | static CORE_ADDR after_prologue (CORE_ADDR pc, | |
107 | alpha_extra_func_info_t proc_desc); | |
108 | ||
109 | static int alpha_in_prologue (CORE_ADDR pc, | |
110 | alpha_extra_func_info_t proc_desc); | |
111 | ||
112 | static int alpha_about_to_return (CORE_ADDR pc); | |
113 | ||
114 | void _initialize_alpha_tdep (void); | |
115 | ||
116 | /* Heuristic_proc_start may hunt through the text section for a long | |
117 | time across a 2400 baud serial line. Allows the user to limit this | |
118 | search. */ | |
119 | static unsigned int heuristic_fence_post = 0; | |
120 | /* *INDENT-OFF* */ | |
121 | /* Layout of a stack frame on the alpha: | |
122 | ||
123 | | | | |
124 | pdr members: | 7th ... nth arg, | | |
125 | | `pushed' by caller. | | |
126 | | | | |
127 | ----------------|-------------------------------|<-- old_sp == vfp | |
128 | ^ ^ ^ ^ | | | |
129 | | | | | | | | |
130 | | |localoff | Copies of 1st .. 6th | | |
131 | | | | | | argument if necessary. | | |
132 | | | | v | | | |
133 | | | | --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS | |
134 | | | | | | | |
135 | | | | | Locals and temporaries. | | |
136 | | | | | | | |
137 | | | | |-------------------------------| | |
138 | | | | | | | |
139 | |-fregoffset | Saved float registers. | | |
140 | | | | | F9 | | |
141 | | | | | . | | |
142 | | | | | . | | |
143 | | | | | F2 | | |
144 | | | v | | | |
145 | | | -------|-------------------------------| | |
146 | | | | | | |
147 | | | | Saved registers. | | |
148 | | | | S6 | | |
149 | |-regoffset | . | | |
150 | | | | . | | |
151 | | | | S0 | | |
152 | | | | pdr.pcreg | | |
153 | | v | | | |
154 | | ----------|-------------------------------| | |
155 | | | | | |
156 | frameoffset | Argument build area, gets | | |
157 | | | 7th ... nth arg for any | | |
158 | | | called procedure. | | |
159 | v | | | |
160 | -------------|-------------------------------|<-- sp | |
161 | | | | |
162 | */ | |
163 | /* *INDENT-ON* */ | |
164 | ||
165 | #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ | |
166 | /* These next two fields are kind of being hijacked. I wonder if | |
167 | iline is too small for the values it needs to hold, if GDB is | |
168 | running on a 32-bit host. */ | |
169 | #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */ | |
170 | #define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */ | |
171 | #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) | |
172 | #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) | |
173 | #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) | |
174 | #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) | |
175 | #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) | |
176 | #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) | |
177 | #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) | |
178 | #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) | |
179 | #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) | |
180 | #define _PROC_MAGIC_ 0x0F0F0F0F | |
181 | #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_) | |
182 | #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_) | |
183 | ||
184 | struct linked_proc_info | |
185 | { | |
186 | struct alpha_extra_func_info info; | |
187 | struct linked_proc_info *next; | |
188 | } | |
189 | *linked_proc_desc_table = NULL; | |
190 | \f | |
191 | static CORE_ADDR | |
192 | alpha_frame_past_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc) | |
193 | { | |
194 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
195 | ||
196 | if (tdep->skip_sigtramp_frame != NULL) | |
197 | return (tdep->skip_sigtramp_frame (frame, pc)); | |
198 | ||
199 | return (0); | |
200 | } | |
201 | ||
202 | static LONGEST | |
203 | alpha_dynamic_sigtramp_offset (CORE_ADDR pc) | |
204 | { | |
205 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
206 | ||
207 | /* Must be provided by OS/ABI variant code if supported. */ | |
208 | if (tdep->dynamic_sigtramp_offset != NULL) | |
209 | return (tdep->dynamic_sigtramp_offset (pc)); | |
210 | ||
211 | return (-1); | |
212 | } | |
213 | ||
214 | #define ALPHA_PROC_SIGTRAMP_MAGIC 0x0e0f0f0f | |
215 | ||
216 | /* Return TRUE if the procedure descriptor PROC is a procedure | |
217 | descriptor that refers to a dynamically generated signal | |
218 | trampoline routine. */ | |
219 | static int | |
220 | alpha_proc_desc_is_dyn_sigtramp (struct alpha_extra_func_info *proc) | |
221 | { | |
222 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
223 | ||
224 | if (tdep->dynamic_sigtramp_offset != NULL) | |
225 | return (proc->pdr.isym == ALPHA_PROC_SIGTRAMP_MAGIC); | |
226 | ||
227 | return (0); | |
228 | } | |
229 | ||
230 | static void | |
231 | alpha_set_proc_desc_is_dyn_sigtramp (struct alpha_extra_func_info *proc) | |
232 | { | |
233 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
234 | ||
235 | if (tdep->dynamic_sigtramp_offset != NULL) | |
236 | proc->pdr.isym = ALPHA_PROC_SIGTRAMP_MAGIC; | |
237 | } | |
238 | ||
239 | /* Dynamically create a signal-handler caller procedure descriptor for | |
240 | the signal-handler return code starting at address LOW_ADDR. The | |
241 | descriptor is added to the linked_proc_desc_table. */ | |
242 | ||
243 | static alpha_extra_func_info_t | |
244 | push_sigtramp_desc (CORE_ADDR low_addr) | |
245 | { | |
246 | struct linked_proc_info *link; | |
247 | alpha_extra_func_info_t proc_desc; | |
248 | ||
249 | link = (struct linked_proc_info *) | |
250 | xmalloc (sizeof (struct linked_proc_info)); | |
251 | link->next = linked_proc_desc_table; | |
252 | linked_proc_desc_table = link; | |
253 | ||
254 | proc_desc = &link->info; | |
255 | ||
256 | proc_desc->numargs = 0; | |
257 | PROC_LOW_ADDR (proc_desc) = low_addr; | |
258 | PROC_HIGH_ADDR (proc_desc) = low_addr + 3 * 4; | |
259 | PROC_DUMMY_FRAME (proc_desc) = 0; | |
260 | PROC_FRAME_OFFSET (proc_desc) = 0x298; /* sizeof(struct sigcontext_struct) */ | |
261 | PROC_FRAME_REG (proc_desc) = SP_REGNUM; | |
262 | PROC_REG_MASK (proc_desc) = 0xffff; | |
263 | PROC_FREG_MASK (proc_desc) = 0xffff; | |
264 | PROC_PC_REG (proc_desc) = 26; | |
265 | PROC_LOCALOFF (proc_desc) = 0; | |
266 | alpha_set_proc_desc_is_dyn_sigtramp (proc_desc); | |
267 | return (proc_desc); | |
268 | } | |
269 | \f | |
270 | ||
271 | static const char * | |
272 | alpha_register_name (int regno) | |
273 | { | |
274 | static char *register_names[] = | |
275 | { | |
276 | "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6", | |
277 | "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp", | |
278 | "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9", | |
279 | "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero", | |
280 | "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", | |
281 | "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", | |
282 | "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", | |
283 | "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr", | |
284 | "pc", "vfp", "unique", | |
285 | }; | |
286 | ||
287 | if (regno < 0) | |
288 | return (NULL); | |
289 | if (regno >= (sizeof(register_names) / sizeof(*register_names))) | |
290 | return (NULL); | |
291 | return (register_names[regno]); | |
292 | } | |
293 | ||
294 | static int | |
295 | alpha_cannot_fetch_register (int regno) | |
296 | { | |
297 | return (regno == FP_REGNUM || regno == ALPHA_ZERO_REGNUM); | |
298 | } | |
299 | ||
300 | static int | |
301 | alpha_cannot_store_register (int regno) | |
302 | { | |
303 | return (regno == FP_REGNUM || regno == ALPHA_ZERO_REGNUM); | |
304 | } | |
305 | ||
306 | static int | |
307 | alpha_register_convertible (int regno) | |
308 | { | |
309 | return (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31); | |
310 | } | |
311 | ||
312 | static struct type * | |
313 | alpha_register_virtual_type (int regno) | |
314 | { | |
315 | return ((regno >= FP0_REGNUM && regno < (FP0_REGNUM+31)) | |
316 | ? builtin_type_double : builtin_type_long); | |
317 | } | |
318 | ||
319 | static int | |
320 | alpha_register_byte (int regno) | |
321 | { | |
322 | return (regno * 8); | |
323 | } | |
324 | ||
325 | static int | |
326 | alpha_register_raw_size (int regno) | |
327 | { | |
328 | return 8; | |
329 | } | |
330 | ||
331 | static int | |
332 | alpha_register_virtual_size (int regno) | |
333 | { | |
334 | return 8; | |
335 | } | |
336 | \f | |
337 | ||
338 | static CORE_ADDR | |
339 | alpha_sigcontext_addr (struct frame_info *fi) | |
340 | { | |
341 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
342 | ||
343 | if (tdep->sigcontext_addr) | |
344 | return (tdep->sigcontext_addr (fi)); | |
345 | ||
346 | return (0); | |
347 | } | |
348 | ||
349 | /* Guaranteed to set frame->saved_regs to some values (it never leaves it | |
350 | NULL). */ | |
351 | ||
352 | static void | |
353 | alpha_find_saved_regs (struct frame_info *frame) | |
354 | { | |
355 | int ireg; | |
356 | CORE_ADDR reg_position; | |
357 | unsigned long mask; | |
358 | alpha_extra_func_info_t proc_desc; | |
359 | int returnreg; | |
360 | ||
361 | frame_saved_regs_zalloc (frame); | |
362 | ||
363 | /* If it is the frame for __sigtramp, the saved registers are located | |
364 | in a sigcontext structure somewhere on the stack. __sigtramp | |
365 | passes a pointer to the sigcontext structure on the stack. | |
366 | If the stack layout for __sigtramp changes, or if sigcontext offsets | |
367 | change, we might have to update this code. */ | |
368 | #ifndef SIGFRAME_PC_OFF | |
369 | #define SIGFRAME_PC_OFF (2 * 8) | |
370 | #define SIGFRAME_REGSAVE_OFF (4 * 8) | |
371 | #define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8) | |
372 | #endif | |
373 | if ((get_frame_type (frame) == SIGTRAMP_FRAME)) | |
374 | { | |
375 | CORE_ADDR sigcontext_addr; | |
376 | ||
377 | sigcontext_addr = alpha_sigcontext_addr (frame); | |
378 | if (sigcontext_addr == 0) | |
379 | { | |
380 | /* Don't know where the sigcontext is; just bail. */ | |
381 | return; | |
382 | } | |
383 | for (ireg = 0; ireg < 32; ireg++) | |
384 | { | |
385 | reg_position = sigcontext_addr + SIGFRAME_REGSAVE_OFF + ireg * 8; | |
386 | get_frame_saved_regs (frame)[ireg] = reg_position; | |
387 | } | |
388 | for (ireg = 0; ireg < 32; ireg++) | |
389 | { | |
390 | reg_position = sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + ireg * 8; | |
391 | get_frame_saved_regs (frame)[FP0_REGNUM + ireg] = reg_position; | |
392 | } | |
393 | get_frame_saved_regs (frame)[PC_REGNUM] = sigcontext_addr + SIGFRAME_PC_OFF; | |
394 | return; | |
395 | } | |
396 | ||
397 | proc_desc = get_frame_extra_info (frame)->proc_desc; | |
398 | if (proc_desc == NULL) | |
399 | /* I'm not sure how/whether this can happen. Normally when we can't | |
400 | find a proc_desc, we "synthesize" one using heuristic_proc_desc | |
401 | and set the saved_regs right away. */ | |
402 | return; | |
403 | ||
404 | /* Fill in the offsets for the registers which gen_mask says | |
405 | were saved. */ | |
406 | ||
407 | reg_position = get_frame_base (frame) + PROC_REG_OFFSET (proc_desc); | |
408 | mask = PROC_REG_MASK (proc_desc); | |
409 | ||
410 | returnreg = PROC_PC_REG (proc_desc); | |
411 | ||
412 | /* Note that RA is always saved first, regardless of its actual | |
413 | register number. */ | |
414 | if (mask & (1 << returnreg)) | |
415 | { | |
416 | get_frame_saved_regs (frame)[returnreg] = reg_position; | |
417 | reg_position += 8; | |
418 | mask &= ~(1 << returnreg); /* Clear bit for RA so we | |
419 | don't save again later. */ | |
420 | } | |
421 | ||
422 | for (ireg = 0; ireg <= 31; ++ireg) | |
423 | if (mask & (1 << ireg)) | |
424 | { | |
425 | get_frame_saved_regs (frame)[ireg] = reg_position; | |
426 | reg_position += 8; | |
427 | } | |
428 | ||
429 | /* Fill in the offsets for the registers which float_mask says | |
430 | were saved. */ | |
431 | ||
432 | reg_position = get_frame_base (frame) + PROC_FREG_OFFSET (proc_desc); | |
433 | mask = PROC_FREG_MASK (proc_desc); | |
434 | ||
435 | for (ireg = 0; ireg <= 31; ++ireg) | |
436 | if (mask & (1 << ireg)) | |
437 | { | |
438 | get_frame_saved_regs (frame)[FP0_REGNUM + ireg] = reg_position; | |
439 | reg_position += 8; | |
440 | } | |
441 | ||
442 | get_frame_saved_regs (frame)[PC_REGNUM] = get_frame_saved_regs (frame)[returnreg]; | |
443 | } | |
444 | ||
445 | static void | |
446 | alpha_frame_init_saved_regs (struct frame_info *fi) | |
447 | { | |
448 | if (get_frame_saved_regs (fi) == NULL) | |
449 | alpha_find_saved_regs (fi); | |
450 | get_frame_saved_regs (fi)[SP_REGNUM] = get_frame_base (fi); | |
451 | } | |
452 | ||
453 | static CORE_ADDR | |
454 | alpha_init_frame_pc_first (int fromleaf, struct frame_info *prev) | |
455 | { | |
456 | return (fromleaf ? SAVED_PC_AFTER_CALL (get_next_frame (prev)) | |
457 | : get_next_frame (prev) ? DEPRECATED_FRAME_SAVED_PC (get_next_frame (prev)) | |
458 | : read_pc ()); | |
459 | } | |
460 | ||
461 | static CORE_ADDR | |
462 | read_next_frame_reg (struct frame_info *fi, int regno) | |
463 | { | |
464 | for (; fi; fi = get_next_frame (fi)) | |
465 | { | |
466 | /* We have to get the saved sp from the sigcontext | |
467 | if it is a signal handler frame. */ | |
468 | if (regno == SP_REGNUM && !(get_frame_type (fi) == SIGTRAMP_FRAME)) | |
469 | return get_frame_base (fi); | |
470 | else | |
471 | { | |
472 | if (get_frame_saved_regs (fi) == NULL) | |
473 | alpha_find_saved_regs (fi); | |
474 | if (get_frame_saved_regs (fi)[regno]) | |
475 | return read_memory_integer (get_frame_saved_regs (fi)[regno], 8); | |
476 | } | |
477 | } | |
478 | return read_register (regno); | |
479 | } | |
480 | ||
481 | static CORE_ADDR | |
482 | alpha_frame_saved_pc (struct frame_info *frame) | |
483 | { | |
484 | alpha_extra_func_info_t proc_desc = get_frame_extra_info (frame)->proc_desc; | |
485 | /* We have to get the saved pc from the sigcontext | |
486 | if it is a signal handler frame. */ | |
487 | int pcreg = ((get_frame_type (frame) == SIGTRAMP_FRAME) | |
488 | ? PC_REGNUM | |
489 | : get_frame_extra_info (frame)->pc_reg); | |
490 | ||
491 | if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc)) | |
492 | return read_memory_integer (get_frame_base (frame) - 8, 8); | |
493 | ||
494 | return read_next_frame_reg (frame, pcreg); | |
495 | } | |
496 | ||
497 | static CORE_ADDR | |
498 | alpha_saved_pc_after_call (struct frame_info *frame) | |
499 | { | |
500 | CORE_ADDR pc = get_frame_pc (frame); | |
501 | CORE_ADDR tmp; | |
502 | alpha_extra_func_info_t proc_desc; | |
503 | int pcreg; | |
504 | ||
505 | /* Skip over shared library trampoline if necessary. */ | |
506 | tmp = SKIP_TRAMPOLINE_CODE (pc); | |
507 | if (tmp != 0) | |
508 | pc = tmp; | |
509 | ||
510 | proc_desc = find_proc_desc (pc, get_next_frame (frame)); | |
511 | pcreg = proc_desc ? PROC_PC_REG (proc_desc) : ALPHA_RA_REGNUM; | |
512 | ||
513 | if ((get_frame_type (frame) == SIGTRAMP_FRAME)) | |
514 | return alpha_frame_saved_pc (frame); | |
515 | else | |
516 | return read_register (pcreg); | |
517 | } | |
518 | ||
519 | ||
520 | static struct alpha_extra_func_info temp_proc_desc; | |
521 | static CORE_ADDR temp_saved_regs[ALPHA_NUM_REGS]; | |
522 | ||
523 | /* Nonzero if instruction at PC is a return instruction. "ret | |
524 | $zero,($ra),1" on alpha. */ | |
525 | ||
526 | static int | |
527 | alpha_about_to_return (CORE_ADDR pc) | |
528 | { | |
529 | return read_memory_integer (pc, 4) == 0x6bfa8001; | |
530 | } | |
531 | ||
532 | ||
533 | ||
534 | /* This fencepost looks highly suspicious to me. Removing it also | |
535 | seems suspicious as it could affect remote debugging across serial | |
536 | lines. */ | |
537 | ||
538 | static CORE_ADDR | |
539 | heuristic_proc_start (CORE_ADDR pc) | |
540 | { | |
541 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
542 | CORE_ADDR start_pc = pc; | |
543 | CORE_ADDR fence = start_pc - heuristic_fence_post; | |
544 | ||
545 | if (start_pc == 0) | |
546 | return 0; | |
547 | ||
548 | if (heuristic_fence_post == UINT_MAX | |
549 | || fence < tdep->vm_min_address) | |
550 | fence = tdep->vm_min_address; | |
551 | ||
552 | /* search back for previous return */ | |
553 | for (start_pc -= 4;; start_pc -= 4) | |
554 | if (start_pc < fence) | |
555 | { | |
556 | /* It's not clear to me why we reach this point when | |
557 | stop_soon, but with this test, at least we | |
558 | don't print out warnings for every child forked (eg, on | |
559 | decstation). 22apr93 rich@cygnus.com. */ | |
560 | if (stop_soon == NO_STOP_QUIETLY) | |
561 | { | |
562 | static int blurb_printed = 0; | |
563 | ||
564 | if (fence == tdep->vm_min_address) | |
565 | warning ("Hit beginning of text section without finding"); | |
566 | else | |
567 | warning ("Hit heuristic-fence-post without finding"); | |
568 | ||
569 | warning ("enclosing function for address 0x%s", paddr_nz (pc)); | |
570 | if (!blurb_printed) | |
571 | { | |
572 | printf_filtered ("\ | |
573 | This warning occurs if you are debugging a function without any symbols\n\ | |
574 | (for example, in a stripped executable). In that case, you may wish to\n\ | |
575 | increase the size of the search with the `set heuristic-fence-post' command.\n\ | |
576 | \n\ | |
577 | Otherwise, you told GDB there was a function where there isn't one, or\n\ | |
578 | (more likely) you have encountered a bug in GDB.\n"); | |
579 | blurb_printed = 1; | |
580 | } | |
581 | } | |
582 | ||
583 | return 0; | |
584 | } | |
585 | else if (alpha_about_to_return (start_pc)) | |
586 | break; | |
587 | ||
588 | start_pc += 4; /* skip return */ | |
589 | return start_pc; | |
590 | } | |
591 | ||
592 | static alpha_extra_func_info_t | |
593 | heuristic_proc_desc (CORE_ADDR start_pc, CORE_ADDR limit_pc, | |
594 | struct frame_info *next_frame) | |
595 | { | |
596 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); | |
597 | CORE_ADDR vfp = sp; | |
598 | CORE_ADDR cur_pc; | |
599 | int frame_size; | |
600 | int has_frame_reg = 0; | |
601 | unsigned long reg_mask = 0; | |
602 | int pcreg = -1; | |
603 | int regno; | |
604 | ||
605 | if (start_pc == 0) | |
606 | return NULL; | |
607 | memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc)); | |
608 | memset (&temp_saved_regs, '\0', SIZEOF_FRAME_SAVED_REGS); | |
609 | PROC_LOW_ADDR (&temp_proc_desc) = start_pc; | |
610 | ||
611 | if (start_pc + 200 < limit_pc) | |
612 | limit_pc = start_pc + 200; | |
613 | frame_size = 0; | |
614 | for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) | |
615 | { | |
616 | char buf[4]; | |
617 | unsigned long word; | |
618 | int status; | |
619 | ||
620 | status = read_memory_nobpt (cur_pc, buf, 4); | |
621 | if (status) | |
622 | memory_error (status, cur_pc); | |
623 | word = extract_unsigned_integer (buf, 4); | |
624 | ||
625 | if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ | |
626 | { | |
627 | if (word & 0x8000) | |
628 | { | |
629 | /* Consider only the first stack allocation instruction | |
630 | to contain the static size of the frame. */ | |
631 | if (frame_size == 0) | |
632 | frame_size += (-word) & 0xffff; | |
633 | } | |
634 | else | |
635 | /* Exit loop if a positive stack adjustment is found, which | |
636 | usually means that the stack cleanup code in the function | |
637 | epilogue is reached. */ | |
638 | break; | |
639 | } | |
640 | else if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ | |
641 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
642 | { | |
643 | int reg = (word & 0x03e00000) >> 21; | |
644 | reg_mask |= 1 << reg; | |
645 | ||
646 | /* Do not compute the address where the register was saved yet, | |
647 | because we don't know yet if the offset will need to be | |
648 | relative to $sp or $fp (we can not compute the address relative | |
649 | to $sp if $sp is updated during the execution of the current | |
650 | subroutine, for instance when doing some alloca). So just store | |
651 | the offset for the moment, and compute the address later | |
652 | when we know whether this frame has a frame pointer or not. | |
653 | */ | |
654 | temp_saved_regs[reg] = (short) word; | |
655 | ||
656 | /* Starting with OSF/1-3.2C, the system libraries are shipped | |
657 | without local symbols, but they still contain procedure | |
658 | descriptors without a symbol reference. GDB is currently | |
659 | unable to find these procedure descriptors and uses | |
660 | heuristic_proc_desc instead. | |
661 | As some low level compiler support routines (__div*, __add*) | |
662 | use a non-standard return address register, we have to | |
663 | add some heuristics to determine the return address register, | |
664 | or stepping over these routines will fail. | |
665 | Usually the return address register is the first register | |
666 | saved on the stack, but assembler optimization might | |
667 | rearrange the register saves. | |
668 | So we recognize only a few registers (t7, t9, ra) within | |
669 | the procedure prologue as valid return address registers. | |
670 | If we encounter a return instruction, we extract the | |
671 | the return address register from it. | |
672 | ||
673 | FIXME: Rewriting GDB to access the procedure descriptors, | |
674 | e.g. via the minimal symbol table, might obviate this hack. */ | |
675 | if (pcreg == -1 | |
676 | && cur_pc < (start_pc + 80) | |
677 | && (reg == ALPHA_T7_REGNUM || reg == ALPHA_T9_REGNUM | |
678 | || reg == ALPHA_RA_REGNUM)) | |
679 | pcreg = reg; | |
680 | } | |
681 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
682 | pcreg = (word >> 16) & 0x1f; | |
683 | else if (word == 0x47de040f || word == 0x47fe040f) /* bis sp,sp fp */ | |
684 | { | |
685 | /* ??? I am not sure what instruction is 0x47fe040f, and I | |
686 | am suspecting that there was a typo and should have been | |
687 | 0x47fe040f. I'm keeping it in the test above until further | |
688 | investigation */ | |
689 | has_frame_reg = 1; | |
690 | vfp = read_next_frame_reg (next_frame, ALPHA_GCC_FP_REGNUM); | |
691 | } | |
692 | } | |
693 | if (pcreg == -1) | |
694 | { | |
695 | /* If we haven't found a valid return address register yet, | |
696 | keep searching in the procedure prologue. */ | |
697 | while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80)) | |
698 | { | |
699 | char buf[4]; | |
700 | unsigned long word; | |
701 | ||
702 | if (read_memory_nobpt (cur_pc, buf, 4)) | |
703 | break; | |
704 | cur_pc += 4; | |
705 | word = extract_unsigned_integer (buf, 4); | |
706 | ||
707 | if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ | |
708 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
709 | { | |
710 | int reg = (word & 0x03e00000) >> 21; | |
711 | if (reg == ALPHA_T7_REGNUM || reg == ALPHA_T9_REGNUM | |
712 | || reg == ALPHA_RA_REGNUM) | |
713 | { | |
714 | pcreg = reg; | |
715 | break; | |
716 | } | |
717 | } | |
718 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
719 | { | |
720 | pcreg = (word >> 16) & 0x1f; | |
721 | break; | |
722 | } | |
723 | } | |
724 | } | |
725 | ||
726 | if (has_frame_reg) | |
727 | PROC_FRAME_REG (&temp_proc_desc) = ALPHA_GCC_FP_REGNUM; | |
728 | else | |
729 | PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM; | |
730 | ||
731 | /* At this point, we know which of the Stack Pointer or the Frame Pointer | |
732 | to use as the reference address to compute the saved registers address. | |
733 | But in both cases, the processing above has set vfp to this reference | |
734 | address, so just need to increment the offset of each saved register | |
735 | by this address. */ | |
736 | for (regno = 0; regno < NUM_REGS; regno++) | |
737 | { | |
738 | if (reg_mask & 1 << regno) | |
739 | temp_saved_regs[regno] += vfp; | |
740 | } | |
741 | ||
742 | PROC_FRAME_OFFSET (&temp_proc_desc) = frame_size; | |
743 | PROC_REG_MASK (&temp_proc_desc) = reg_mask; | |
744 | PROC_PC_REG (&temp_proc_desc) = (pcreg == -1) ? ALPHA_RA_REGNUM : pcreg; | |
745 | PROC_LOCALOFF (&temp_proc_desc) = 0; /* XXX - bogus */ | |
746 | return &temp_proc_desc; | |
747 | } | |
748 | ||
749 | /* This returns the PC of the first inst after the prologue. If we can't | |
750 | find the prologue, then return 0. */ | |
751 | ||
752 | static CORE_ADDR | |
753 | after_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) | |
754 | { | |
755 | struct symtab_and_line sal; | |
756 | CORE_ADDR func_addr, func_end; | |
757 | ||
758 | if (!proc_desc) | |
759 | proc_desc = find_proc_desc (pc, NULL); | |
760 | ||
761 | if (proc_desc) | |
762 | { | |
763 | if (alpha_proc_desc_is_dyn_sigtramp (proc_desc)) | |
764 | return PROC_LOW_ADDR (proc_desc); /* "prologue" is in kernel */ | |
765 | ||
766 | /* If function is frameless, then we need to do it the hard way. I | |
767 | strongly suspect that frameless always means prologueless... */ | |
768 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM | |
769 | && PROC_FRAME_OFFSET (proc_desc) == 0) | |
770 | return 0; | |
771 | } | |
772 | ||
773 | if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
774 | return 0; /* Unknown */ | |
775 | ||
776 | sal = find_pc_line (func_addr, 0); | |
777 | ||
778 | if (sal.end < func_end) | |
779 | return sal.end; | |
780 | ||
781 | /* The line after the prologue is after the end of the function. In this | |
782 | case, tell the caller to find the prologue the hard way. */ | |
783 | ||
784 | return 0; | |
785 | } | |
786 | ||
787 | /* Return non-zero if we *might* be in a function prologue. Return zero if we | |
788 | are definitively *not* in a function prologue. */ | |
789 | ||
790 | static int | |
791 | alpha_in_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) | |
792 | { | |
793 | CORE_ADDR after_prologue_pc; | |
794 | ||
795 | after_prologue_pc = after_prologue (pc, proc_desc); | |
796 | ||
797 | if (after_prologue_pc == 0 | |
798 | || pc < after_prologue_pc) | |
799 | return 1; | |
800 | else | |
801 | return 0; | |
802 | } | |
803 | ||
804 | static alpha_extra_func_info_t | |
805 | find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame) | |
806 | { | |
807 | alpha_extra_func_info_t proc_desc; | |
808 | struct block *b; | |
809 | struct symbol *sym; | |
810 | CORE_ADDR startaddr; | |
811 | ||
812 | /* Try to get the proc_desc from the linked call dummy proc_descs | |
813 | if the pc is in the call dummy. | |
814 | This is hairy. In the case of nested dummy calls we have to find the | |
815 | right proc_desc, but we might not yet know the frame for the dummy | |
816 | as it will be contained in the proc_desc we are searching for. | |
817 | So we have to find the proc_desc whose frame is closest to the current | |
818 | stack pointer. */ | |
819 | ||
820 | if (DEPRECATED_PC_IN_CALL_DUMMY (pc, 0, 0)) | |
821 | { | |
822 | struct linked_proc_info *link; | |
823 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); | |
824 | alpha_extra_func_info_t found_proc_desc = NULL; | |
825 | long min_distance = LONG_MAX; | |
826 | ||
827 | for (link = linked_proc_desc_table; link; link = link->next) | |
828 | { | |
829 | long distance = (CORE_ADDR) PROC_DUMMY_FRAME (&link->info) - sp; | |
830 | if (distance > 0 && distance < min_distance) | |
831 | { | |
832 | min_distance = distance; | |
833 | found_proc_desc = &link->info; | |
834 | } | |
835 | } | |
836 | if (found_proc_desc != NULL) | |
837 | return found_proc_desc; | |
838 | } | |
839 | ||
840 | b = block_for_pc (pc); | |
841 | ||
842 | find_pc_partial_function (pc, NULL, &startaddr, NULL); | |
843 | if (b == NULL) | |
844 | sym = NULL; | |
845 | else | |
846 | { | |
847 | if (startaddr > BLOCK_START (b)) | |
848 | /* This is the "pathological" case referred to in a comment in | |
849 | print_frame_info. It might be better to move this check into | |
850 | symbol reading. */ | |
851 | sym = NULL; | |
852 | else | |
853 | sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, | |
854 | 0, NULL); | |
855 | } | |
856 | ||
857 | /* If we never found a PDR for this function in symbol reading, then | |
858 | examine prologues to find the information. */ | |
859 | if (sym && ((mips_extra_func_info_t) SYMBOL_VALUE (sym))->pdr.framereg == -1) | |
860 | sym = NULL; | |
861 | ||
862 | if (sym) | |
863 | { | |
864 | /* IF this is the topmost frame AND | |
865 | * (this proc does not have debugging information OR | |
866 | * the PC is in the procedure prologue) | |
867 | * THEN create a "heuristic" proc_desc (by analyzing | |
868 | * the actual code) to replace the "official" proc_desc. | |
869 | */ | |
870 | proc_desc = (alpha_extra_func_info_t) SYMBOL_VALUE (sym); | |
871 | if (next_frame == NULL) | |
872 | { | |
873 | if (PROC_DESC_IS_DUMMY (proc_desc) || alpha_in_prologue (pc, proc_desc)) | |
874 | { | |
875 | alpha_extra_func_info_t found_heuristic = | |
876 | heuristic_proc_desc (PROC_LOW_ADDR (proc_desc), | |
877 | pc, next_frame); | |
878 | if (found_heuristic) | |
879 | { | |
880 | PROC_LOCALOFF (found_heuristic) = | |
881 | PROC_LOCALOFF (proc_desc); | |
882 | PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc); | |
883 | proc_desc = found_heuristic; | |
884 | } | |
885 | } | |
886 | } | |
887 | } | |
888 | else | |
889 | { | |
890 | long offset; | |
891 | ||
892 | /* Is linked_proc_desc_table really necessary? It only seems to be used | |
893 | by procedure call dummys. However, the procedures being called ought | |
894 | to have their own proc_descs, and even if they don't, | |
895 | heuristic_proc_desc knows how to create them! */ | |
896 | ||
897 | register struct linked_proc_info *link; | |
898 | for (link = linked_proc_desc_table; link; link = link->next) | |
899 | if (PROC_LOW_ADDR (&link->info) <= pc | |
900 | && PROC_HIGH_ADDR (&link->info) > pc) | |
901 | return &link->info; | |
902 | ||
903 | /* If PC is inside a dynamically generated sigtramp handler, | |
904 | create and push a procedure descriptor for that code: */ | |
905 | offset = alpha_dynamic_sigtramp_offset (pc); | |
906 | if (offset >= 0) | |
907 | return push_sigtramp_desc (pc - offset); | |
908 | ||
909 | /* If heuristic_fence_post is non-zero, determine the procedure | |
910 | start address by examining the instructions. | |
911 | This allows us to find the start address of static functions which | |
912 | have no symbolic information, as startaddr would have been set to | |
913 | the preceding global function start address by the | |
914 | find_pc_partial_function call above. */ | |
915 | if (startaddr == 0 || heuristic_fence_post != 0) | |
916 | startaddr = heuristic_proc_start (pc); | |
917 | ||
918 | proc_desc = | |
919 | heuristic_proc_desc (startaddr, pc, next_frame); | |
920 | } | |
921 | return proc_desc; | |
922 | } | |
923 | ||
924 | alpha_extra_func_info_t cached_proc_desc; | |
925 | ||
926 | static CORE_ADDR | |
927 | alpha_frame_chain (struct frame_info *frame) | |
928 | { | |
929 | alpha_extra_func_info_t proc_desc; | |
930 | CORE_ADDR saved_pc = DEPRECATED_FRAME_SAVED_PC (frame); | |
931 | ||
932 | if (saved_pc == 0 || inside_entry_file (saved_pc)) | |
933 | return 0; | |
934 | ||
935 | proc_desc = find_proc_desc (saved_pc, frame); | |
936 | if (!proc_desc) | |
937 | return 0; | |
938 | ||
939 | cached_proc_desc = proc_desc; | |
940 | ||
941 | /* Fetch the frame pointer for a dummy frame from the procedure | |
942 | descriptor. */ | |
943 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
944 | return (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc); | |
945 | ||
946 | /* If no frame pointer and frame size is zero, we must be at end | |
947 | of stack (or otherwise hosed). If we don't check frame size, | |
948 | we loop forever if we see a zero size frame. */ | |
949 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM | |
950 | && PROC_FRAME_OFFSET (proc_desc) == 0 | |
951 | /* The previous frame from a sigtramp frame might be frameless | |
952 | and have frame size zero. */ | |
953 | && !(get_frame_type (frame) == SIGTRAMP_FRAME)) | |
954 | return alpha_frame_past_sigtramp_frame (frame, saved_pc); | |
955 | else | |
956 | return read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc)) | |
957 | + PROC_FRAME_OFFSET (proc_desc); | |
958 | } | |
959 | ||
960 | void | |
961 | alpha_print_extra_frame_info (struct frame_info *fi) | |
962 | { | |
963 | if (fi | |
964 | && get_frame_extra_info (fi) | |
965 | && get_frame_extra_info (fi)->proc_desc | |
966 | && get_frame_extra_info (fi)->proc_desc->pdr.framereg < NUM_REGS) | |
967 | printf_filtered (" frame pointer is at %s+%s\n", | |
968 | REGISTER_NAME (get_frame_extra_info (fi)->proc_desc->pdr.framereg), | |
969 | paddr_d (get_frame_extra_info (fi)->proc_desc->pdr.frameoffset)); | |
970 | } | |
971 | ||
972 | static void | |
973 | alpha_init_extra_frame_info (int fromleaf, struct frame_info *frame) | |
974 | { | |
975 | /* Use proc_desc calculated in frame_chain */ | |
976 | alpha_extra_func_info_t proc_desc = | |
977 | get_next_frame (frame) | |
978 | ? cached_proc_desc | |
979 | : find_proc_desc (get_frame_pc (frame), get_next_frame (frame)); | |
980 | ||
981 | frame_extra_info_zalloc (frame, sizeof (struct frame_extra_info)); | |
982 | ||
983 | /* NOTE: cagney/2003-01-03: No need to set saved_regs to NULL, | |
984 | always NULL by default. */ | |
985 | /* frame->saved_regs = NULL; */ | |
986 | get_frame_extra_info (frame)->localoff = 0; | |
987 | get_frame_extra_info (frame)->pc_reg = ALPHA_RA_REGNUM; | |
988 | get_frame_extra_info (frame)->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc; | |
989 | if (proc_desc) | |
990 | { | |
991 | /* Get the locals offset and the saved pc register from the | |
992 | procedure descriptor, they are valid even if we are in the | |
993 | middle of the prologue. */ | |
994 | get_frame_extra_info (frame)->localoff = PROC_LOCALOFF (proc_desc); | |
995 | get_frame_extra_info (frame)->pc_reg = PROC_PC_REG (proc_desc); | |
996 | ||
997 | /* Fixup frame-pointer - only needed for top frame */ | |
998 | ||
999 | /* Fetch the frame pointer for a dummy frame from the procedure | |
1000 | descriptor. */ | |
1001 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
1002 | deprecated_update_frame_base_hack (frame, (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc)); | |
1003 | ||
1004 | /* This may not be quite right, if proc has a real frame register. | |
1005 | Get the value of the frame relative sp, procedure might have been | |
1006 | interrupted by a signal at it's very start. */ | |
1007 | else if (get_frame_pc (frame) == PROC_LOW_ADDR (proc_desc) | |
1008 | && !alpha_proc_desc_is_dyn_sigtramp (proc_desc)) | |
1009 | deprecated_update_frame_base_hack (frame, read_next_frame_reg (get_next_frame (frame), SP_REGNUM)); | |
1010 | else | |
1011 | deprecated_update_frame_base_hack (frame, read_next_frame_reg (get_next_frame (frame), PROC_FRAME_REG (proc_desc)) | |
1012 | + PROC_FRAME_OFFSET (proc_desc)); | |
1013 | ||
1014 | if (proc_desc == &temp_proc_desc) | |
1015 | { | |
1016 | char *name; | |
1017 | ||
1018 | /* Do not set the saved registers for a sigtramp frame, | |
1019 | alpha_find_saved_registers will do that for us. We can't | |
1020 | use (get_frame_type (frame) == SIGTRAMP_FRAME), it is not | |
1021 | yet set. */ | |
1022 | /* FIXME: cagney/2002-11-18: This problem will go away once | |
1023 | frame.c:get_prev_frame() is modified to set the frame's | |
1024 | type before calling functions like this. */ | |
1025 | find_pc_partial_function (get_frame_pc (frame), &name, | |
1026 | (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); | |
1027 | if (!PC_IN_SIGTRAMP (get_frame_pc (frame), name)) | |
1028 | { | |
1029 | frame_saved_regs_zalloc (frame); | |
1030 | memcpy (get_frame_saved_regs (frame), temp_saved_regs, | |
1031 | SIZEOF_FRAME_SAVED_REGS); | |
1032 | get_frame_saved_regs (frame)[PC_REGNUM] | |
1033 | = get_frame_saved_regs (frame)[ALPHA_RA_REGNUM]; | |
1034 | } | |
1035 | } | |
1036 | } | |
1037 | } | |
1038 | ||
1039 | static CORE_ADDR | |
1040 | alpha_frame_locals_address (struct frame_info *fi) | |
1041 | { | |
1042 | return (get_frame_base (fi) - get_frame_extra_info (fi)->localoff); | |
1043 | } | |
1044 | ||
1045 | static CORE_ADDR | |
1046 | alpha_frame_args_address (struct frame_info *fi) | |
1047 | { | |
1048 | return (get_frame_base (fi) - (ALPHA_NUM_ARG_REGS * 8)); | |
1049 | } | |
1050 | ||
1051 | /* ALPHA stack frames are almost impenetrable. When execution stops, | |
1052 | we basically have to look at symbol information for the function | |
1053 | that we stopped in, which tells us *which* register (if any) is | |
1054 | the base of the frame pointer, and what offset from that register | |
1055 | the frame itself is at. | |
1056 | ||
1057 | This presents a problem when trying to examine a stack in memory | |
1058 | (that isn't executing at the moment), using the "frame" command. We | |
1059 | don't have a PC, nor do we have any registers except SP. | |
1060 | ||
1061 | This routine takes two arguments, SP and PC, and tries to make the | |
1062 | cached frames look as if these two arguments defined a frame on the | |
1063 | cache. This allows the rest of info frame to extract the important | |
1064 | arguments without difficulty. */ | |
1065 | ||
1066 | struct frame_info * | |
1067 | alpha_setup_arbitrary_frame (int argc, CORE_ADDR *argv) | |
1068 | { | |
1069 | if (argc != 2) | |
1070 | error ("ALPHA frame specifications require two arguments: sp and pc"); | |
1071 | ||
1072 | return create_new_frame (argv[0], argv[1]); | |
1073 | } | |
1074 | ||
1075 | /* The alpha passes the first six arguments in the registers, the rest on | |
1076 | the stack. The register arguments are eventually transferred to the | |
1077 | argument transfer area immediately below the stack by the called function | |
1078 | anyway. So we `push' at least six arguments on the stack, `reload' the | |
1079 | argument registers and then adjust the stack pointer to point past the | |
1080 | sixth argument. This algorithm simplifies the passing of a large struct | |
1081 | which extends from the registers to the stack. | |
1082 | If the called function is returning a structure, the address of the | |
1083 | structure to be returned is passed as a hidden first argument. */ | |
1084 | ||
1085 | static CORE_ADDR | |
1086 | alpha_push_arguments (int nargs, struct value **args, CORE_ADDR sp, | |
1087 | int struct_return, CORE_ADDR struct_addr) | |
1088 | { | |
1089 | int i; | |
1090 | int accumulate_size = struct_return ? 8 : 0; | |
1091 | int arg_regs_size = ALPHA_NUM_ARG_REGS * 8; | |
1092 | struct alpha_arg | |
1093 | { | |
1094 | char *contents; | |
1095 | int len; | |
1096 | int offset; | |
1097 | }; | |
1098 | struct alpha_arg *alpha_args = | |
1099 | (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg)); | |
1100 | register struct alpha_arg *m_arg; | |
1101 | char raw_buffer[sizeof (CORE_ADDR)]; | |
1102 | int required_arg_regs; | |
1103 | ||
1104 | for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++) | |
1105 | { | |
1106 | struct value *arg = args[i]; | |
1107 | struct type *arg_type = check_typedef (VALUE_TYPE (arg)); | |
1108 | /* Cast argument to long if necessary as the compiler does it too. */ | |
1109 | switch (TYPE_CODE (arg_type)) | |
1110 | { | |
1111 | case TYPE_CODE_INT: | |
1112 | case TYPE_CODE_BOOL: | |
1113 | case TYPE_CODE_CHAR: | |
1114 | case TYPE_CODE_RANGE: | |
1115 | case TYPE_CODE_ENUM: | |
1116 | if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long)) | |
1117 | { | |
1118 | arg_type = builtin_type_long; | |
1119 | arg = value_cast (arg_type, arg); | |
1120 | } | |
1121 | break; | |
1122 | default: | |
1123 | break; | |
1124 | } | |
1125 | m_arg->len = TYPE_LENGTH (arg_type); | |
1126 | m_arg->offset = accumulate_size; | |
1127 | accumulate_size = (accumulate_size + m_arg->len + 7) & ~7; | |
1128 | m_arg->contents = VALUE_CONTENTS (arg); | |
1129 | } | |
1130 | ||
1131 | /* Determine required argument register loads, loading an argument register | |
1132 | is expensive as it uses three ptrace calls. */ | |
1133 | required_arg_regs = accumulate_size / 8; | |
1134 | if (required_arg_regs > ALPHA_NUM_ARG_REGS) | |
1135 | required_arg_regs = ALPHA_NUM_ARG_REGS; | |
1136 | ||
1137 | /* Make room for the arguments on the stack. */ | |
1138 | if (accumulate_size < arg_regs_size) | |
1139 | accumulate_size = arg_regs_size; | |
1140 | sp -= accumulate_size; | |
1141 | ||
1142 | /* Keep sp aligned to a multiple of 16 as the compiler does it too. */ | |
1143 | sp &= ~15; | |
1144 | ||
1145 | /* `Push' arguments on the stack. */ | |
1146 | for (i = nargs; m_arg--, --i >= 0;) | |
1147 | write_memory (sp + m_arg->offset, m_arg->contents, m_arg->len); | |
1148 | if (struct_return) | |
1149 | { | |
1150 | store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr); | |
1151 | write_memory (sp, raw_buffer, sizeof (CORE_ADDR)); | |
1152 | } | |
1153 | ||
1154 | /* Load the argument registers. */ | |
1155 | for (i = 0; i < required_arg_regs; i++) | |
1156 | { | |
1157 | LONGEST val; | |
1158 | ||
1159 | val = read_memory_integer (sp + i * 8, 8); | |
1160 | write_register (ALPHA_A0_REGNUM + i, val); | |
1161 | write_register (ALPHA_FPA0_REGNUM + i, val); | |
1162 | } | |
1163 | ||
1164 | return sp + arg_regs_size; | |
1165 | } | |
1166 | ||
1167 | static void | |
1168 | alpha_push_dummy_frame (void) | |
1169 | { | |
1170 | int ireg; | |
1171 | struct linked_proc_info *link; | |
1172 | alpha_extra_func_info_t proc_desc; | |
1173 | CORE_ADDR sp = read_register (SP_REGNUM); | |
1174 | CORE_ADDR save_address; | |
1175 | char raw_buffer[ALPHA_MAX_REGISTER_RAW_SIZE]; | |
1176 | unsigned long mask; | |
1177 | ||
1178 | link = (struct linked_proc_info *) xmalloc (sizeof (struct linked_proc_info)); | |
1179 | link->next = linked_proc_desc_table; | |
1180 | linked_proc_desc_table = link; | |
1181 | ||
1182 | proc_desc = &link->info; | |
1183 | ||
1184 | /* | |
1185 | * The registers we must save are all those not preserved across | |
1186 | * procedure calls. | |
1187 | * In addition, we must save the PC and RA. | |
1188 | * | |
1189 | * Dummy frame layout: | |
1190 | * (high memory) | |
1191 | * Saved PC | |
1192 | * Saved F30 | |
1193 | * ... | |
1194 | * Saved F0 | |
1195 | * Saved R29 | |
1196 | * ... | |
1197 | * Saved R0 | |
1198 | * Saved R26 (RA) | |
1199 | * Parameter build area | |
1200 | * (low memory) | |
1201 | */ | |
1202 | ||
1203 | /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */ | |
1204 | #define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1)) | |
1205 | #define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29)) | |
1206 | #define GEN_REG_SAVE_COUNT 24 | |
1207 | #define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30)) | |
1208 | #define FLOAT_REG_SAVE_COUNT 23 | |
1209 | /* The special register is the PC as we have no bit for it in the save masks. | |
1210 | alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */ | |
1211 | #define SPECIAL_REG_SAVE_COUNT 1 | |
1212 | ||
1213 | PROC_REG_MASK (proc_desc) = GEN_REG_SAVE_MASK; | |
1214 | PROC_FREG_MASK (proc_desc) = FLOAT_REG_SAVE_MASK; | |
1215 | /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA, | |
1216 | but keep SP aligned to a multiple of 16. */ | |
1217 | PROC_REG_OFFSET (proc_desc) = | |
1218 | -((8 * (SPECIAL_REG_SAVE_COUNT | |
1219 | + GEN_REG_SAVE_COUNT | |
1220 | + FLOAT_REG_SAVE_COUNT) | |
1221 | + 15) & ~15); | |
1222 | PROC_FREG_OFFSET (proc_desc) = | |
1223 | PROC_REG_OFFSET (proc_desc) + 8 * GEN_REG_SAVE_COUNT; | |
1224 | ||
1225 | /* Save general registers. | |
1226 | The return address register is the first saved register, all other | |
1227 | registers follow in ascending order. | |
1228 | The PC is saved immediately below the SP. */ | |
1229 | save_address = sp + PROC_REG_OFFSET (proc_desc); | |
1230 | store_address (raw_buffer, 8, read_register (ALPHA_RA_REGNUM)); | |
1231 | write_memory (save_address, raw_buffer, 8); | |
1232 | save_address += 8; | |
1233 | mask = PROC_REG_MASK (proc_desc) & 0xffffffffL; | |
1234 | for (ireg = 0; mask; ireg++, mask >>= 1) | |
1235 | if (mask & 1) | |
1236 | { | |
1237 | if (ireg == ALPHA_RA_REGNUM) | |
1238 | continue; | |
1239 | store_address (raw_buffer, 8, read_register (ireg)); | |
1240 | write_memory (save_address, raw_buffer, 8); | |
1241 | save_address += 8; | |
1242 | } | |
1243 | ||
1244 | store_address (raw_buffer, 8, read_register (PC_REGNUM)); | |
1245 | write_memory (sp - 8, raw_buffer, 8); | |
1246 | ||
1247 | /* Save floating point registers. */ | |
1248 | save_address = sp + PROC_FREG_OFFSET (proc_desc); | |
1249 | mask = PROC_FREG_MASK (proc_desc) & 0xffffffffL; | |
1250 | for (ireg = 0; mask; ireg++, mask >>= 1) | |
1251 | if (mask & 1) | |
1252 | { | |
1253 | store_address (raw_buffer, 8, read_register (ireg + FP0_REGNUM)); | |
1254 | write_memory (save_address, raw_buffer, 8); | |
1255 | save_address += 8; | |
1256 | } | |
1257 | ||
1258 | /* Set and save the frame address for the dummy. | |
1259 | This is tricky. The only registers that are suitable for a frame save | |
1260 | are those that are preserved across procedure calls (s0-s6). But if | |
1261 | a read system call is interrupted and then a dummy call is made | |
1262 | (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read | |
1263 | is satisfied. Then it returns with the s0-s6 registers set to the values | |
1264 | on entry to the read system call and our dummy frame pointer would be | |
1265 | destroyed. So we save the dummy frame in the proc_desc and handle the | |
1266 | retrieval of the frame pointer of a dummy specifically. The frame register | |
1267 | is set to the virtual frame (pseudo) register, it's value will always | |
1268 | be read as zero and will help us to catch any errors in the dummy frame | |
1269 | retrieval code. */ | |
1270 | PROC_DUMMY_FRAME (proc_desc) = sp; | |
1271 | PROC_FRAME_REG (proc_desc) = FP_REGNUM; | |
1272 | PROC_FRAME_OFFSET (proc_desc) = 0; | |
1273 | sp += PROC_REG_OFFSET (proc_desc); | |
1274 | write_register (SP_REGNUM, sp); | |
1275 | ||
1276 | PROC_LOW_ADDR (proc_desc) = CALL_DUMMY_ADDRESS (); | |
1277 | PROC_HIGH_ADDR (proc_desc) = PROC_LOW_ADDR (proc_desc) + 4; | |
1278 | ||
1279 | SET_PROC_DESC_IS_DUMMY (proc_desc); | |
1280 | PROC_PC_REG (proc_desc) = ALPHA_RA_REGNUM; | |
1281 | } | |
1282 | ||
1283 | static void | |
1284 | alpha_pop_frame (void) | |
1285 | { | |
1286 | register int regnum; | |
1287 | struct frame_info *frame = get_current_frame (); | |
1288 | CORE_ADDR new_sp = get_frame_base (frame); | |
1289 | ||
1290 | alpha_extra_func_info_t proc_desc = get_frame_extra_info (frame)->proc_desc; | |
1291 | ||
1292 | /* we need proc_desc to know how to restore the registers; | |
1293 | if it is NULL, construct (a temporary) one */ | |
1294 | if (proc_desc == NULL) | |
1295 | proc_desc = find_proc_desc (get_frame_pc (frame), get_next_frame (frame)); | |
1296 | ||
1297 | /* Question: should we copy this proc_desc and save it in | |
1298 | frame->proc_desc? If we do, who will free it? | |
1299 | For now, we don't save a copy... */ | |
1300 | ||
1301 | write_register (PC_REGNUM, DEPRECATED_FRAME_SAVED_PC (frame)); | |
1302 | if (get_frame_saved_regs (frame) == NULL) | |
1303 | alpha_find_saved_regs (frame); | |
1304 | if (proc_desc) | |
1305 | { | |
1306 | for (regnum = 32; --regnum >= 0;) | |
1307 | if (PROC_REG_MASK (proc_desc) & (1 << regnum)) | |
1308 | write_register (regnum, | |
1309 | read_memory_integer (get_frame_saved_regs (frame)[regnum], | |
1310 | 8)); | |
1311 | for (regnum = 32; --regnum >= 0;) | |
1312 | if (PROC_FREG_MASK (proc_desc) & (1 << regnum)) | |
1313 | write_register (regnum + FP0_REGNUM, | |
1314 | read_memory_integer (get_frame_saved_regs (frame)[regnum + FP0_REGNUM], 8)); | |
1315 | } | |
1316 | write_register (SP_REGNUM, new_sp); | |
1317 | flush_cached_frames (); | |
1318 | ||
1319 | if (proc_desc && (PROC_DESC_IS_DUMMY (proc_desc) | |
1320 | || alpha_proc_desc_is_dyn_sigtramp (proc_desc))) | |
1321 | { | |
1322 | struct linked_proc_info *pi_ptr, *prev_ptr; | |
1323 | ||
1324 | for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL; | |
1325 | pi_ptr != NULL; | |
1326 | prev_ptr = pi_ptr, pi_ptr = pi_ptr->next) | |
1327 | { | |
1328 | if (&pi_ptr->info == proc_desc) | |
1329 | break; | |
1330 | } | |
1331 | ||
1332 | if (pi_ptr == NULL) | |
1333 | error ("Can't locate dummy extra frame info\n"); | |
1334 | ||
1335 | if (prev_ptr != NULL) | |
1336 | prev_ptr->next = pi_ptr->next; | |
1337 | else | |
1338 | linked_proc_desc_table = pi_ptr->next; | |
1339 | ||
1340 | xfree (pi_ptr); | |
1341 | } | |
1342 | } | |
1343 | \f | |
1344 | /* To skip prologues, I use this predicate. Returns either PC itself | |
1345 | if the code at PC does not look like a function prologue; otherwise | |
1346 | returns an address that (if we're lucky) follows the prologue. If | |
1347 | LENIENT, then we must skip everything which is involved in setting | |
1348 | up the frame (it's OK to skip more, just so long as we don't skip | |
1349 | anything which might clobber the registers which are being saved. | |
1350 | Currently we must not skip more on the alpha, but we might need the | |
1351 | lenient stuff some day. */ | |
1352 | ||
1353 | static CORE_ADDR | |
1354 | alpha_skip_prologue_internal (CORE_ADDR pc, int lenient) | |
1355 | { | |
1356 | unsigned long inst; | |
1357 | int offset; | |
1358 | CORE_ADDR post_prologue_pc; | |
1359 | char buf[4]; | |
1360 | ||
1361 | /* Silently return the unaltered pc upon memory errors. | |
1362 | This could happen on OSF/1 if decode_line_1 tries to skip the | |
1363 | prologue for quickstarted shared library functions when the | |
1364 | shared library is not yet mapped in. | |
1365 | Reading target memory is slow over serial lines, so we perform | |
1366 | this check only if the target has shared libraries (which all | |
1367 | Alpha targets do). */ | |
1368 | if (target_read_memory (pc, buf, 4)) | |
1369 | return pc; | |
1370 | ||
1371 | /* See if we can determine the end of the prologue via the symbol table. | |
1372 | If so, then return either PC, or the PC after the prologue, whichever | |
1373 | is greater. */ | |
1374 | ||
1375 | post_prologue_pc = after_prologue (pc, NULL); | |
1376 | ||
1377 | if (post_prologue_pc != 0) | |
1378 | return max (pc, post_prologue_pc); | |
1379 | ||
1380 | /* Can't determine prologue from the symbol table, need to examine | |
1381 | instructions. */ | |
1382 | ||
1383 | /* Skip the typical prologue instructions. These are the stack adjustment | |
1384 | instruction and the instructions that save registers on the stack | |
1385 | or in the gcc frame. */ | |
1386 | for (offset = 0; offset < 100; offset += 4) | |
1387 | { | |
1388 | int status; | |
1389 | ||
1390 | status = read_memory_nobpt (pc + offset, buf, 4); | |
1391 | if (status) | |
1392 | memory_error (status, pc + offset); | |
1393 | inst = extract_unsigned_integer (buf, 4); | |
1394 | ||
1395 | /* The alpha has no delay slots. But let's keep the lenient stuff, | |
1396 | we might need it for something else in the future. */ | |
1397 | if (lenient && 0) | |
1398 | continue; | |
1399 | ||
1400 | if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */ | |
1401 | continue; | |
1402 | if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */ | |
1403 | continue; | |
1404 | if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ | |
1405 | continue; | |
1406 | if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */ | |
1407 | continue; | |
1408 | ||
1409 | if ((inst & 0xfc1f0000) == 0xb41e0000 | |
1410 | && (inst & 0xffff0000) != 0xb7fe0000) | |
1411 | continue; /* stq reg,n($sp) */ | |
1412 | /* reg != $zero */ | |
1413 | if ((inst & 0xfc1f0000) == 0x9c1e0000 | |
1414 | && (inst & 0xffff0000) != 0x9ffe0000) | |
1415 | continue; /* stt reg,n($sp) */ | |
1416 | /* reg != $zero */ | |
1417 | if (inst == 0x47de040f) /* bis sp,sp,fp */ | |
1418 | continue; | |
1419 | ||
1420 | break; | |
1421 | } | |
1422 | return pc + offset; | |
1423 | } | |
1424 | ||
1425 | static CORE_ADDR | |
1426 | alpha_skip_prologue (CORE_ADDR addr) | |
1427 | { | |
1428 | return (alpha_skip_prologue_internal (addr, 0)); | |
1429 | } | |
1430 | ||
1431 | #if 0 | |
1432 | /* Is address PC in the prologue (loosely defined) for function at | |
1433 | STARTADDR? */ | |
1434 | ||
1435 | static int | |
1436 | alpha_in_lenient_prologue (CORE_ADDR startaddr, CORE_ADDR pc) | |
1437 | { | |
1438 | CORE_ADDR end_prologue = alpha_skip_prologue_internal (startaddr, 1); | |
1439 | return pc >= startaddr && pc < end_prologue; | |
1440 | } | |
1441 | #endif | |
1442 | ||
1443 | /* The alpha needs a conversion between register and memory format if | |
1444 | the register is a floating point register and | |
1445 | memory format is float, as the register format must be double | |
1446 | or | |
1447 | memory format is an integer with 4 bytes or less, as the representation | |
1448 | of integers in floating point registers is different. */ | |
1449 | static void | |
1450 | alpha_register_convert_to_virtual (int regnum, struct type *valtype, | |
1451 | char *raw_buffer, char *virtual_buffer) | |
1452 | { | |
1453 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1454 | { | |
1455 | memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum)); | |
1456 | return; | |
1457 | } | |
1458 | ||
1459 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1460 | { | |
1461 | double d = extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1462 | store_floating (virtual_buffer, TYPE_LENGTH (valtype), d); | |
1463 | } | |
1464 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1465 | { | |
1466 | ULONGEST l; | |
1467 | l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1468 | l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff); | |
1469 | store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l); | |
1470 | } | |
1471 | else | |
1472 | error ("Cannot retrieve value from floating point register"); | |
1473 | } | |
1474 | ||
1475 | static void | |
1476 | alpha_register_convert_to_raw (struct type *valtype, int regnum, | |
1477 | char *virtual_buffer, char *raw_buffer) | |
1478 | { | |
1479 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1480 | { | |
1481 | memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum)); | |
1482 | return; | |
1483 | } | |
1484 | ||
1485 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1486 | { | |
1487 | double d = extract_floating (virtual_buffer, TYPE_LENGTH (valtype)); | |
1488 | store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d); | |
1489 | } | |
1490 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1491 | { | |
1492 | ULONGEST l; | |
1493 | if (TYPE_UNSIGNED (valtype)) | |
1494 | l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1495 | else | |
1496 | l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1497 | l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29); | |
1498 | store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l); | |
1499 | } | |
1500 | else | |
1501 | error ("Cannot store value in floating point register"); | |
1502 | } | |
1503 | ||
1504 | static const unsigned char * | |
1505 | alpha_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) | |
1506 | { | |
1507 | static const unsigned char alpha_breakpoint[] = | |
1508 | { 0x80, 0, 0, 0 }; /* call_pal bpt */ | |
1509 | ||
1510 | *lenptr = sizeof(alpha_breakpoint); | |
1511 | return (alpha_breakpoint); | |
1512 | } | |
1513 | ||
1514 | /* Given a return value in `regbuf' with a type `valtype', | |
1515 | extract and copy its value into `valbuf'. */ | |
1516 | ||
1517 | static void | |
1518 | alpha_extract_return_value (struct type *valtype, | |
1519 | char regbuf[ALPHA_REGISTER_BYTES], char *valbuf) | |
1520 | { | |
1521 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1522 | alpha_register_convert_to_virtual (FP0_REGNUM, valtype, | |
1523 | regbuf + REGISTER_BYTE (FP0_REGNUM), | |
1524 | valbuf); | |
1525 | else | |
1526 | memcpy (valbuf, regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM), | |
1527 | TYPE_LENGTH (valtype)); | |
1528 | } | |
1529 | ||
1530 | /* Given a return value in `regbuf' with a type `valtype', | |
1531 | write its value into the appropriate register. */ | |
1532 | ||
1533 | static void | |
1534 | alpha_store_return_value (struct type *valtype, char *valbuf) | |
1535 | { | |
1536 | char raw_buffer[ALPHA_MAX_REGISTER_RAW_SIZE]; | |
1537 | int regnum = ALPHA_V0_REGNUM; | |
1538 | int length = TYPE_LENGTH (valtype); | |
1539 | ||
1540 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1541 | { | |
1542 | regnum = FP0_REGNUM; | |
1543 | length = REGISTER_RAW_SIZE (regnum); | |
1544 | alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer); | |
1545 | } | |
1546 | else | |
1547 | memcpy (raw_buffer, valbuf, length); | |
1548 | ||
1549 | deprecated_write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length); | |
1550 | } | |
1551 | ||
1552 | /* Just like reinit_frame_cache, but with the right arguments to be | |
1553 | callable as an sfunc. */ | |
1554 | ||
1555 | static void | |
1556 | reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c) | |
1557 | { | |
1558 | reinit_frame_cache (); | |
1559 | } | |
1560 | ||
1561 | /* This is the definition of CALL_DUMMY_ADDRESS. It's a heuristic that is used | |
1562 | to find a convenient place in the text segment to stick a breakpoint to | |
1563 | detect the completion of a target function call (ala call_function_by_hand). | |
1564 | */ | |
1565 | ||
1566 | CORE_ADDR | |
1567 | alpha_call_dummy_address (void) | |
1568 | { | |
1569 | CORE_ADDR entry; | |
1570 | struct minimal_symbol *sym; | |
1571 | ||
1572 | entry = entry_point_address (); | |
1573 | ||
1574 | if (entry != 0) | |
1575 | return entry; | |
1576 | ||
1577 | sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile); | |
1578 | ||
1579 | if (!sym || MSYMBOL_TYPE (sym) != mst_text) | |
1580 | return 0; | |
1581 | else | |
1582 | return SYMBOL_VALUE_ADDRESS (sym) + 4; | |
1583 | } | |
1584 | ||
1585 | static void | |
1586 | alpha_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, | |
1587 | struct value **args, struct type *type, int gcc_p) | |
1588 | { | |
1589 | CORE_ADDR bp_address = CALL_DUMMY_ADDRESS (); | |
1590 | ||
1591 | if (bp_address == 0) | |
1592 | error ("no place to put call"); | |
1593 | write_register (ALPHA_RA_REGNUM, bp_address); | |
1594 | write_register (ALPHA_T12_REGNUM, fun); | |
1595 | } | |
1596 | ||
1597 | /* On the Alpha, the call dummy code is nevery copied to user space | |
1598 | (see alpha_fix_call_dummy() above). The contents of this do not | |
1599 | matter. */ | |
1600 | LONGEST alpha_call_dummy_words[] = { 0 }; | |
1601 | ||
1602 | static int | |
1603 | alpha_use_struct_convention (int gcc_p, struct type *type) | |
1604 | { | |
1605 | /* Structures are returned by ref in extra arg0. */ | |
1606 | return 1; | |
1607 | } | |
1608 | ||
1609 | static void | |
1610 | alpha_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) | |
1611 | { | |
1612 | /* Store the address of the place in which to copy the structure the | |
1613 | subroutine will return. Handled by alpha_push_arguments. */ | |
1614 | } | |
1615 | ||
1616 | static CORE_ADDR | |
1617 | alpha_extract_struct_value_address (char *regbuf) | |
1618 | { | |
1619 | return (extract_address (regbuf + REGISTER_BYTE (ALPHA_V0_REGNUM), | |
1620 | REGISTER_RAW_SIZE (ALPHA_V0_REGNUM))); | |
1621 | } | |
1622 | ||
1623 | /* Figure out where the longjmp will land. | |
1624 | We expect the first arg to be a pointer to the jmp_buf structure from | |
1625 | which we extract the PC (JB_PC) that we will land at. The PC is copied | |
1626 | into the "pc". This routine returns true on success. */ | |
1627 | ||
1628 | static int | |
1629 | alpha_get_longjmp_target (CORE_ADDR *pc) | |
1630 | { | |
1631 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
1632 | CORE_ADDR jb_addr; | |
1633 | char raw_buffer[ALPHA_MAX_REGISTER_RAW_SIZE]; | |
1634 | ||
1635 | jb_addr = read_register (ALPHA_A0_REGNUM); | |
1636 | ||
1637 | if (target_read_memory (jb_addr + (tdep->jb_pc * tdep->jb_elt_size), | |
1638 | raw_buffer, tdep->jb_elt_size)) | |
1639 | return 0; | |
1640 | ||
1641 | *pc = extract_address (raw_buffer, tdep->jb_elt_size); | |
1642 | return 1; | |
1643 | } | |
1644 | ||
1645 | /* alpha_software_single_step() is called just before we want to resume | |
1646 | the inferior, if we want to single-step it but there is no hardware | |
1647 | or kernel single-step support (NetBSD on Alpha, for example). We find | |
1648 | the target of the coming instruction and breakpoint it. | |
1649 | ||
1650 | single_step is also called just after the inferior stops. If we had | |
1651 | set up a simulated single-step, we undo our damage. */ | |
1652 | ||
1653 | static CORE_ADDR | |
1654 | alpha_next_pc (CORE_ADDR pc) | |
1655 | { | |
1656 | unsigned int insn; | |
1657 | unsigned int op; | |
1658 | int offset; | |
1659 | LONGEST rav; | |
1660 | ||
1661 | insn = read_memory_unsigned_integer (pc, sizeof (insn)); | |
1662 | ||
1663 | /* Opcode is top 6 bits. */ | |
1664 | op = (insn >> 26) & 0x3f; | |
1665 | ||
1666 | if (op == 0x1a) | |
1667 | { | |
1668 | /* Jump format: target PC is: | |
1669 | RB & ~3 */ | |
1670 | return (read_register ((insn >> 16) & 0x1f) & ~3); | |
1671 | } | |
1672 | ||
1673 | if ((op & 0x30) == 0x30) | |
1674 | { | |
1675 | /* Branch format: target PC is: | |
1676 | (new PC) + (4 * sext(displacement)) */ | |
1677 | if (op == 0x30 || /* BR */ | |
1678 | op == 0x34) /* BSR */ | |
1679 | { | |
1680 | branch_taken: | |
1681 | offset = (insn & 0x001fffff); | |
1682 | if (offset & 0x00100000) | |
1683 | offset |= 0xffe00000; | |
1684 | offset *= 4; | |
1685 | return (pc + 4 + offset); | |
1686 | } | |
1687 | ||
1688 | /* Need to determine if branch is taken; read RA. */ | |
1689 | rav = (LONGEST) read_register ((insn >> 21) & 0x1f); | |
1690 | switch (op) | |
1691 | { | |
1692 | case 0x38: /* BLBC */ | |
1693 | if ((rav & 1) == 0) | |
1694 | goto branch_taken; | |
1695 | break; | |
1696 | case 0x3c: /* BLBS */ | |
1697 | if (rav & 1) | |
1698 | goto branch_taken; | |
1699 | break; | |
1700 | case 0x39: /* BEQ */ | |
1701 | if (rav == 0) | |
1702 | goto branch_taken; | |
1703 | break; | |
1704 | case 0x3d: /* BNE */ | |
1705 | if (rav != 0) | |
1706 | goto branch_taken; | |
1707 | break; | |
1708 | case 0x3a: /* BLT */ | |
1709 | if (rav < 0) | |
1710 | goto branch_taken; | |
1711 | break; | |
1712 | case 0x3b: /* BLE */ | |
1713 | if (rav <= 0) | |
1714 | goto branch_taken; | |
1715 | break; | |
1716 | case 0x3f: /* BGT */ | |
1717 | if (rav > 0) | |
1718 | goto branch_taken; | |
1719 | break; | |
1720 | case 0x3e: /* BGE */ | |
1721 | if (rav >= 0) | |
1722 | goto branch_taken; | |
1723 | break; | |
1724 | } | |
1725 | } | |
1726 | ||
1727 | /* Not a branch or branch not taken; target PC is: | |
1728 | pc + 4 */ | |
1729 | return (pc + 4); | |
1730 | } | |
1731 | ||
1732 | void | |
1733 | alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p) | |
1734 | { | |
1735 | static CORE_ADDR next_pc; | |
1736 | typedef char binsn_quantum[BREAKPOINT_MAX]; | |
1737 | static binsn_quantum break_mem; | |
1738 | CORE_ADDR pc; | |
1739 | ||
1740 | if (insert_breakpoints_p) | |
1741 | { | |
1742 | pc = read_pc (); | |
1743 | next_pc = alpha_next_pc (pc); | |
1744 | ||
1745 | target_insert_breakpoint (next_pc, break_mem); | |
1746 | } | |
1747 | else | |
1748 | { | |
1749 | target_remove_breakpoint (next_pc, break_mem); | |
1750 | write_pc (next_pc); | |
1751 | } | |
1752 | } | |
1753 | ||
1754 | \f | |
1755 | ||
1756 | /* Initialize the current architecture based on INFO. If possible, re-use an | |
1757 | architecture from ARCHES, which is a list of architectures already created | |
1758 | during this debugging session. | |
1759 | ||
1760 | Called e.g. at program startup, when reading a core file, and when reading | |
1761 | a binary file. */ | |
1762 | ||
1763 | static struct gdbarch * | |
1764 | alpha_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) | |
1765 | { | |
1766 | struct gdbarch_tdep *tdep; | |
1767 | struct gdbarch *gdbarch; | |
1768 | ||
1769 | /* Try to determine the ABI of the object we are loading. */ | |
1770 | if (info.abfd != NULL && info.osabi == GDB_OSABI_UNKNOWN) | |
1771 | { | |
1772 | /* If it's an ECOFF file, assume it's OSF/1. */ | |
1773 | if (bfd_get_flavour (info.abfd) == bfd_target_ecoff_flavour) | |
1774 | info.osabi = GDB_OSABI_OSF1; | |
1775 | } | |
1776 | ||
1777 | /* Find a candidate among extant architectures. */ | |
1778 | arches = gdbarch_list_lookup_by_info (arches, &info); | |
1779 | if (arches != NULL) | |
1780 | return arches->gdbarch; | |
1781 | ||
1782 | tdep = xmalloc (sizeof (struct gdbarch_tdep)); | |
1783 | gdbarch = gdbarch_alloc (&info, tdep); | |
1784 | ||
1785 | /* Lowest text address. This is used by heuristic_proc_start() to | |
1786 | decide when to stop looking. */ | |
1787 | tdep->vm_min_address = (CORE_ADDR) 0x120000000; | |
1788 | ||
1789 | tdep->dynamic_sigtramp_offset = NULL; | |
1790 | tdep->skip_sigtramp_frame = NULL; | |
1791 | tdep->sigcontext_addr = NULL; | |
1792 | ||
1793 | tdep->jb_pc = -1; /* longjmp support not enabled by default */ | |
1794 | ||
1795 | /* Type sizes */ | |
1796 | set_gdbarch_short_bit (gdbarch, 16); | |
1797 | set_gdbarch_int_bit (gdbarch, 32); | |
1798 | set_gdbarch_long_bit (gdbarch, 64); | |
1799 | set_gdbarch_long_long_bit (gdbarch, 64); | |
1800 | set_gdbarch_float_bit (gdbarch, 32); | |
1801 | set_gdbarch_double_bit (gdbarch, 64); | |
1802 | set_gdbarch_long_double_bit (gdbarch, 64); | |
1803 | set_gdbarch_ptr_bit (gdbarch, 64); | |
1804 | ||
1805 | /* Register info */ | |
1806 | set_gdbarch_num_regs (gdbarch, ALPHA_NUM_REGS); | |
1807 | set_gdbarch_sp_regnum (gdbarch, ALPHA_SP_REGNUM); | |
1808 | set_gdbarch_fp_regnum (gdbarch, ALPHA_FP_REGNUM); | |
1809 | set_gdbarch_pc_regnum (gdbarch, ALPHA_PC_REGNUM); | |
1810 | set_gdbarch_fp0_regnum (gdbarch, ALPHA_FP0_REGNUM); | |
1811 | ||
1812 | set_gdbarch_register_name (gdbarch, alpha_register_name); | |
1813 | set_gdbarch_register_size (gdbarch, ALPHA_REGISTER_SIZE); | |
1814 | set_gdbarch_register_bytes (gdbarch, ALPHA_REGISTER_BYTES); | |
1815 | set_gdbarch_register_byte (gdbarch, alpha_register_byte); | |
1816 | set_gdbarch_register_raw_size (gdbarch, alpha_register_raw_size); | |
1817 | set_gdbarch_deprecated_max_register_raw_size (gdbarch, ALPHA_MAX_REGISTER_RAW_SIZE); | |
1818 | set_gdbarch_register_virtual_size (gdbarch, alpha_register_virtual_size); | |
1819 | set_gdbarch_deprecated_max_register_virtual_size (gdbarch, | |
1820 | ALPHA_MAX_REGISTER_VIRTUAL_SIZE); | |
1821 | set_gdbarch_register_virtual_type (gdbarch, alpha_register_virtual_type); | |
1822 | ||
1823 | set_gdbarch_cannot_fetch_register (gdbarch, alpha_cannot_fetch_register); | |
1824 | set_gdbarch_cannot_store_register (gdbarch, alpha_cannot_store_register); | |
1825 | ||
1826 | set_gdbarch_register_convertible (gdbarch, alpha_register_convertible); | |
1827 | set_gdbarch_register_convert_to_virtual (gdbarch, | |
1828 | alpha_register_convert_to_virtual); | |
1829 | set_gdbarch_register_convert_to_raw (gdbarch, alpha_register_convert_to_raw); | |
1830 | ||
1831 | set_gdbarch_skip_prologue (gdbarch, alpha_skip_prologue); | |
1832 | ||
1833 | set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown); | |
1834 | set_gdbarch_frameless_function_invocation (gdbarch, | |
1835 | generic_frameless_function_invocation_not); | |
1836 | ||
1837 | set_gdbarch_saved_pc_after_call (gdbarch, alpha_saved_pc_after_call); | |
1838 | ||
1839 | set_gdbarch_deprecated_frame_chain (gdbarch, alpha_frame_chain); | |
1840 | set_gdbarch_deprecated_frame_saved_pc (gdbarch, alpha_frame_saved_pc); | |
1841 | ||
1842 | set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, alpha_frame_init_saved_regs); | |
1843 | ||
1844 | set_gdbarch_use_struct_convention (gdbarch, alpha_use_struct_convention); | |
1845 | set_gdbarch_deprecated_extract_return_value (gdbarch, alpha_extract_return_value); | |
1846 | ||
1847 | set_gdbarch_deprecated_store_struct_return (gdbarch, alpha_store_struct_return); | |
1848 | set_gdbarch_deprecated_store_return_value (gdbarch, alpha_store_return_value); | |
1849 | set_gdbarch_deprecated_extract_struct_value_address (gdbarch, | |
1850 | alpha_extract_struct_value_address); | |
1851 | ||
1852 | /* Settings for calling functions in the inferior. */ | |
1853 | set_gdbarch_deprecated_use_generic_dummy_frames (gdbarch, 0); | |
1854 | set_gdbarch_deprecated_push_arguments (gdbarch, alpha_push_arguments); | |
1855 | set_gdbarch_deprecated_pop_frame (gdbarch, alpha_pop_frame); | |
1856 | ||
1857 | /* On the Alpha, the call dummy code is never copied to user space, | |
1858 | stopping the user call is achieved via a bp_call_dummy breakpoint. | |
1859 | But we need a fake CALL_DUMMY definition to enable the proper | |
1860 | call_function_by_hand and to avoid zero length array warnings. */ | |
1861 | set_gdbarch_call_dummy_words (gdbarch, alpha_call_dummy_words); | |
1862 | set_gdbarch_sizeof_call_dummy_words (gdbarch, 0); | |
1863 | set_gdbarch_frame_args_address (gdbarch, alpha_frame_args_address); | |
1864 | set_gdbarch_frame_locals_address (gdbarch, alpha_frame_locals_address); | |
1865 | set_gdbarch_deprecated_init_extra_frame_info (gdbarch, alpha_init_extra_frame_info); | |
1866 | ||
1867 | /* Alpha OSF/1 inhibits execution of code on the stack. But there is | |
1868 | no need for a dummy on the Alpha. PUSH_ARGUMENTS takes care of all | |
1869 | argument handling and bp_call_dummy takes care of stopping the dummy. */ | |
1870 | set_gdbarch_call_dummy_address (gdbarch, alpha_call_dummy_address); | |
1871 | set_gdbarch_deprecated_pc_in_call_dummy (gdbarch, deprecated_pc_in_call_dummy_at_entry_point); | |
1872 | set_gdbarch_deprecated_push_dummy_frame (gdbarch, alpha_push_dummy_frame); | |
1873 | /* Should be using push_dummy_call. */ | |
1874 | set_gdbarch_deprecated_dummy_write_sp (gdbarch, generic_target_write_sp); | |
1875 | set_gdbarch_fix_call_dummy (gdbarch, alpha_fix_call_dummy); | |
1876 | set_gdbarch_deprecated_init_frame_pc (gdbarch, init_frame_pc_noop); | |
1877 | set_gdbarch_deprecated_init_frame_pc_first (gdbarch, alpha_init_frame_pc_first); | |
1878 | ||
1879 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); | |
1880 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); | |
1881 | ||
1882 | set_gdbarch_breakpoint_from_pc (gdbarch, alpha_breakpoint_from_pc); | |
1883 | set_gdbarch_decr_pc_after_break (gdbarch, 4); | |
1884 | ||
1885 | set_gdbarch_function_start_offset (gdbarch, 0); | |
1886 | set_gdbarch_frame_args_skip (gdbarch, 0); | |
1887 | ||
1888 | /* Hook in ABI-specific overrides, if they have been registered. */ | |
1889 | gdbarch_init_osabi (info, gdbarch); | |
1890 | ||
1891 | /* Now that we have tuned the configuration, set a few final things | |
1892 | based on what the OS ABI has told us. */ | |
1893 | ||
1894 | if (tdep->jb_pc >= 0) | |
1895 | set_gdbarch_get_longjmp_target (gdbarch, alpha_get_longjmp_target); | |
1896 | ||
1897 | return gdbarch; | |
1898 | } | |
1899 | ||
1900 | static void | |
1901 | alpha_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file) | |
1902 | { | |
1903 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); | |
1904 | ||
1905 | if (tdep == NULL) | |
1906 | return; | |
1907 | ||
1908 | fprintf_unfiltered (file, | |
1909 | "alpha_dump_tdep: vm_min_address = 0x%lx\n", | |
1910 | (long) tdep->vm_min_address); | |
1911 | ||
1912 | fprintf_unfiltered (file, | |
1913 | "alpha_dump_tdep: jb_pc = %d\n", | |
1914 | tdep->jb_pc); | |
1915 | fprintf_unfiltered (file, | |
1916 | "alpha_dump_tdep: jb_elt_size = %ld\n", | |
1917 | (long) tdep->jb_elt_size); | |
1918 | } | |
1919 | ||
1920 | void | |
1921 | _initialize_alpha_tdep (void) | |
1922 | { | |
1923 | struct cmd_list_element *c; | |
1924 | ||
1925 | gdbarch_register (bfd_arch_alpha, alpha_gdbarch_init, alpha_dump_tdep); | |
1926 | ||
1927 | tm_print_insn = print_insn_alpha; | |
1928 | ||
1929 | /* Let the user set the fence post for heuristic_proc_start. */ | |
1930 | ||
1931 | /* We really would like to have both "0" and "unlimited" work, but | |
1932 | command.c doesn't deal with that. So make it a var_zinteger | |
1933 | because the user can always use "999999" or some such for unlimited. */ | |
1934 | c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger, | |
1935 | (char *) &heuristic_fence_post, | |
1936 | "\ | |
1937 | Set the distance searched for the start of a function.\n\ | |
1938 | If you are debugging a stripped executable, GDB needs to search through the\n\ | |
1939 | program for the start of a function. This command sets the distance of the\n\ | |
1940 | search. The only need to set it is when debugging a stripped executable.", | |
1941 | &setlist); | |
1942 | /* We need to throw away the frame cache when we set this, since it | |
1943 | might change our ability to get backtraces. */ | |
1944 | set_cmd_sfunc (c, reinit_frame_cache_sfunc); | |
1945 | add_show_from_set (c, &showlist); | |
1946 | } |