Commit | Line | Data |
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c906108c | 1 | /* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger. |
ec32e4be | 2 | Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 |
b6ba6518 | 3 | Free Software Foundation, Inc. |
c906108c | 4 | |
c5aa993b | 5 | This file is part of GDB. |
c906108c | 6 | |
c5aa993b JM |
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. | |
c906108c | 11 | |
c5aa993b JM |
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. | |
c906108c | 16 | |
c5aa993b JM |
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. */ | |
c906108c SS |
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" | |
c5f0f3d0 | 33 | #include "linespec.h" |
4e052eda | 34 | #include "regcache.h" |
d16aafd8 | 35 | #include "doublest.h" |
c906108c SS |
36 | |
37 | /* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */ | |
38 | ||
39 | /* Prototypes for local functions. */ | |
40 | ||
a14ed312 | 41 | static alpha_extra_func_info_t push_sigtramp_desc (CORE_ADDR low_addr); |
c906108c | 42 | |
a14ed312 | 43 | static CORE_ADDR read_next_frame_reg (struct frame_info *, int); |
c906108c | 44 | |
a14ed312 | 45 | static CORE_ADDR heuristic_proc_start (CORE_ADDR); |
c906108c | 46 | |
a14ed312 KB |
47 | static alpha_extra_func_info_t heuristic_proc_desc (CORE_ADDR, |
48 | CORE_ADDR, | |
49 | struct frame_info *); | |
c906108c | 50 | |
a14ed312 KB |
51 | static alpha_extra_func_info_t find_proc_desc (CORE_ADDR, |
52 | struct frame_info *); | |
c906108c SS |
53 | |
54 | #if 0 | |
a14ed312 | 55 | static int alpha_in_lenient_prologue (CORE_ADDR, CORE_ADDR); |
c906108c SS |
56 | #endif |
57 | ||
a14ed312 | 58 | static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element *); |
c906108c | 59 | |
a14ed312 KB |
60 | static CORE_ADDR after_prologue (CORE_ADDR pc, |
61 | alpha_extra_func_info_t proc_desc); | |
c906108c | 62 | |
a14ed312 KB |
63 | static int alpha_in_prologue (CORE_ADDR pc, |
64 | alpha_extra_func_info_t proc_desc); | |
c906108c | 65 | |
a14ed312 | 66 | static int alpha_about_to_return (CORE_ADDR pc); |
392a587b | 67 | |
a14ed312 | 68 | void _initialize_alpha_tdep (void); |
392a587b | 69 | |
c906108c SS |
70 | /* Heuristic_proc_start may hunt through the text section for a long |
71 | time across a 2400 baud serial line. Allows the user to limit this | |
72 | search. */ | |
73 | static unsigned int heuristic_fence_post = 0; | |
c5aa993b | 74 | /* *INDENT-OFF* */ |
c906108c SS |
75 | /* Layout of a stack frame on the alpha: |
76 | ||
77 | | | | |
78 | pdr members: | 7th ... nth arg, | | |
79 | | `pushed' by caller. | | |
80 | | | | |
81 | ----------------|-------------------------------|<-- old_sp == vfp | |
82 | ^ ^ ^ ^ | | | |
83 | | | | | | | | |
84 | | |localoff | Copies of 1st .. 6th | | |
85 | | | | | | argument if necessary. | | |
86 | | | | v | | | |
87 | | | | --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS | |
88 | | | | | | | |
89 | | | | | Locals and temporaries. | | |
90 | | | | | | | |
91 | | | | |-------------------------------| | |
92 | | | | | | | |
93 | |-fregoffset | Saved float registers. | | |
94 | | | | | F9 | | |
95 | | | | | . | | |
96 | | | | | . | | |
97 | | | | | F2 | | |
98 | | | v | | | |
99 | | | -------|-------------------------------| | |
100 | | | | | | |
101 | | | | Saved registers. | | |
102 | | | | S6 | | |
103 | |-regoffset | . | | |
104 | | | | . | | |
105 | | | | S0 | | |
106 | | | | pdr.pcreg | | |
107 | | v | | | |
108 | | ----------|-------------------------------| | |
109 | | | | | |
110 | frameoffset | Argument build area, gets | | |
111 | | | 7th ... nth arg for any | | |
112 | | | called procedure. | | |
113 | v | | | |
114 | -------------|-------------------------------|<-- sp | |
115 | | | | |
116 | */ | |
c5aa993b JM |
117 | /* *INDENT-ON* */ |
118 | ||
119 | ||
c906108c | 120 | |
c5aa993b | 121 | #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ |
b83266a0 SS |
122 | /* These next two fields are kind of being hijacked. I wonder if |
123 | iline is too small for the values it needs to hold, if GDB is | |
124 | running on a 32-bit host. */ | |
c5aa993b JM |
125 | #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */ |
126 | #define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */ | |
c906108c SS |
127 | #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) |
128 | #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) | |
129 | #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) | |
130 | #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) | |
131 | #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) | |
132 | #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) | |
133 | #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) | |
134 | #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) | |
135 | #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) | |
136 | #define _PROC_MAGIC_ 0x0F0F0F0F | |
137 | #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_) | |
138 | #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_) | |
139 | ||
140 | struct linked_proc_info | |
c5aa993b JM |
141 | { |
142 | struct alpha_extra_func_info info; | |
143 | struct linked_proc_info *next; | |
144 | } | |
145 | *linked_proc_desc_table = NULL; | |
c906108c | 146 | \f |
c5aa993b | 147 | |
c906108c SS |
148 | /* Under GNU/Linux, signal handler invocations can be identified by the |
149 | designated code sequence that is used to return from a signal | |
150 | handler. In particular, the return address of a signal handler | |
151 | points to the following sequence (the first instruction is quadword | |
152 | aligned): | |
153 | ||
c5aa993b JM |
154 | bis $30,$30,$16 |
155 | addq $31,0x67,$0 | |
156 | call_pal callsys | |
c906108c SS |
157 | |
158 | Each instruction has a unique encoding, so we simply attempt to | |
159 | match the instruction the pc is pointing to with any of the above | |
160 | instructions. If there is a hit, we know the offset to the start | |
161 | of the designated sequence and can then check whether we really are | |
162 | executing in a designated sequence. If not, -1 is returned, | |
163 | otherwise the offset from the start of the desingated sequence is | |
164 | returned. | |
165 | ||
166 | There is a slight chance of false hits: code could jump into the | |
167 | middle of the designated sequence, in which case there is no | |
168 | guarantee that we are in the middle of a sigreturn syscall. Don't | |
169 | think this will be a problem in praxis, though. | |
c5aa993b | 170 | */ |
c906108c | 171 | |
7a292a7a SS |
172 | #ifndef TM_LINUXALPHA_H |
173 | /* HACK: Provide a prototype when compiling this file for non | |
174 | linuxalpha targets. */ | |
a14ed312 | 175 | long alpha_linux_sigtramp_offset (CORE_ADDR pc); |
7a292a7a | 176 | #endif |
c906108c | 177 | long |
fba45db2 | 178 | alpha_linux_sigtramp_offset (CORE_ADDR pc) |
c906108c SS |
179 | { |
180 | unsigned int i[3], w; | |
181 | long off; | |
182 | ||
c5aa993b | 183 | if (read_memory_nobpt (pc, (char *) &w, 4) != 0) |
c906108c SS |
184 | return -1; |
185 | ||
186 | off = -1; | |
187 | switch (w) | |
188 | { | |
c5aa993b JM |
189 | case 0x47de0410: |
190 | off = 0; | |
191 | break; /* bis $30,$30,$16 */ | |
192 | case 0x43ecf400: | |
193 | off = 4; | |
194 | break; /* addq $31,0x67,$0 */ | |
195 | case 0x00000083: | |
196 | off = 8; | |
197 | break; /* call_pal callsys */ | |
198 | default: | |
199 | return -1; | |
c906108c SS |
200 | } |
201 | pc -= off; | |
202 | if (pc & 0x7) | |
203 | { | |
204 | /* designated sequence is not quadword aligned */ | |
205 | return -1; | |
206 | } | |
207 | ||
c5aa993b | 208 | if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0) |
c906108c SS |
209 | return -1; |
210 | ||
211 | if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083) | |
212 | return off; | |
213 | ||
214 | return -1; | |
215 | } | |
c906108c | 216 | \f |
c5aa993b | 217 | |
c906108c SS |
218 | /* Under OSF/1, the __sigtramp routine is frameless and has a frame |
219 | size of zero, but we are able to backtrace through it. */ | |
220 | CORE_ADDR | |
fba45db2 | 221 | alpha_osf_skip_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc) |
c906108c SS |
222 | { |
223 | char *name; | |
c5aa993b | 224 | find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
c906108c SS |
225 | if (IN_SIGTRAMP (pc, name)) |
226 | return frame->frame; | |
227 | else | |
228 | return 0; | |
229 | } | |
c906108c | 230 | \f |
c5aa993b | 231 | |
c906108c SS |
232 | /* Dynamically create a signal-handler caller procedure descriptor for |
233 | the signal-handler return code starting at address LOW_ADDR. The | |
234 | descriptor is added to the linked_proc_desc_table. */ | |
235 | ||
236 | static alpha_extra_func_info_t | |
fba45db2 | 237 | push_sigtramp_desc (CORE_ADDR low_addr) |
c906108c SS |
238 | { |
239 | struct linked_proc_info *link; | |
240 | alpha_extra_func_info_t proc_desc; | |
241 | ||
242 | link = (struct linked_proc_info *) | |
243 | xmalloc (sizeof (struct linked_proc_info)); | |
244 | link->next = linked_proc_desc_table; | |
245 | linked_proc_desc_table = link; | |
246 | ||
247 | proc_desc = &link->info; | |
248 | ||
249 | proc_desc->numargs = 0; | |
c5aa993b JM |
250 | PROC_LOW_ADDR (proc_desc) = low_addr; |
251 | PROC_HIGH_ADDR (proc_desc) = low_addr + 3 * 4; | |
252 | PROC_DUMMY_FRAME (proc_desc) = 0; | |
253 | PROC_FRAME_OFFSET (proc_desc) = 0x298; /* sizeof(struct sigcontext_struct) */ | |
254 | PROC_FRAME_REG (proc_desc) = SP_REGNUM; | |
255 | PROC_REG_MASK (proc_desc) = 0xffff; | |
256 | PROC_FREG_MASK (proc_desc) = 0xffff; | |
257 | PROC_PC_REG (proc_desc) = 26; | |
258 | PROC_LOCALOFF (proc_desc) = 0; | |
c906108c SS |
259 | SET_PROC_DESC_IS_DYN_SIGTRAMP (proc_desc); |
260 | return (proc_desc); | |
261 | } | |
c906108c | 262 | \f |
c5aa993b | 263 | |
636a6dfc JT |
264 | char * |
265 | alpha_register_name (int regno) | |
266 | { | |
267 | static char *register_names[] = | |
268 | { | |
269 | "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6", | |
270 | "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp", | |
271 | "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9", | |
272 | "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero", | |
273 | "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", | |
274 | "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", | |
275 | "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", | |
276 | "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr", | |
277 | "pc", "vfp", | |
278 | }; | |
279 | ||
280 | if (regno < 0) | |
281 | return (NULL); | |
282 | if (regno >= (sizeof(register_names) / sizeof(*register_names))) | |
283 | return (NULL); | |
284 | return (register_names[regno]); | |
285 | } | |
286 | \f | |
287 | ||
c906108c SS |
288 | /* Guaranteed to set frame->saved_regs to some values (it never leaves it |
289 | NULL). */ | |
290 | ||
291 | void | |
fba45db2 | 292 | alpha_find_saved_regs (struct frame_info *frame) |
c906108c SS |
293 | { |
294 | int ireg; | |
295 | CORE_ADDR reg_position; | |
296 | unsigned long mask; | |
297 | alpha_extra_func_info_t proc_desc; | |
298 | int returnreg; | |
299 | ||
300 | frame_saved_regs_zalloc (frame); | |
301 | ||
302 | /* If it is the frame for __sigtramp, the saved registers are located | |
303 | in a sigcontext structure somewhere on the stack. __sigtramp | |
304 | passes a pointer to the sigcontext structure on the stack. | |
305 | If the stack layout for __sigtramp changes, or if sigcontext offsets | |
306 | change, we might have to update this code. */ | |
307 | #ifndef SIGFRAME_PC_OFF | |
308 | #define SIGFRAME_PC_OFF (2 * 8) | |
309 | #define SIGFRAME_REGSAVE_OFF (4 * 8) | |
310 | #define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8) | |
311 | #endif | |
312 | if (frame->signal_handler_caller) | |
313 | { | |
314 | CORE_ADDR sigcontext_addr; | |
315 | ||
316 | sigcontext_addr = SIGCONTEXT_ADDR (frame); | |
317 | for (ireg = 0; ireg < 32; ireg++) | |
318 | { | |
c5aa993b JM |
319 | reg_position = sigcontext_addr + SIGFRAME_REGSAVE_OFF + ireg * 8; |
320 | frame->saved_regs[ireg] = reg_position; | |
c906108c SS |
321 | } |
322 | for (ireg = 0; ireg < 32; ireg++) | |
323 | { | |
c5aa993b JM |
324 | reg_position = sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + ireg * 8; |
325 | frame->saved_regs[FP0_REGNUM + ireg] = reg_position; | |
c906108c SS |
326 | } |
327 | frame->saved_regs[PC_REGNUM] = sigcontext_addr + SIGFRAME_PC_OFF; | |
328 | return; | |
329 | } | |
330 | ||
331 | proc_desc = frame->proc_desc; | |
332 | if (proc_desc == NULL) | |
333 | /* I'm not sure how/whether this can happen. Normally when we can't | |
334 | find a proc_desc, we "synthesize" one using heuristic_proc_desc | |
335 | and set the saved_regs right away. */ | |
336 | return; | |
337 | ||
338 | /* Fill in the offsets for the registers which gen_mask says | |
339 | were saved. */ | |
340 | ||
341 | reg_position = frame->frame + PROC_REG_OFFSET (proc_desc); | |
342 | mask = PROC_REG_MASK (proc_desc); | |
343 | ||
344 | returnreg = PROC_PC_REG (proc_desc); | |
345 | ||
346 | /* Note that RA is always saved first, regardless of its actual | |
347 | register number. */ | |
348 | if (mask & (1 << returnreg)) | |
349 | { | |
350 | frame->saved_regs[returnreg] = reg_position; | |
351 | reg_position += 8; | |
c5aa993b JM |
352 | mask &= ~(1 << returnreg); /* Clear bit for RA so we |
353 | don't save again later. */ | |
c906108c SS |
354 | } |
355 | ||
c5aa993b | 356 | for (ireg = 0; ireg <= 31; ++ireg) |
c906108c SS |
357 | if (mask & (1 << ireg)) |
358 | { | |
359 | frame->saved_regs[ireg] = reg_position; | |
360 | reg_position += 8; | |
361 | } | |
362 | ||
363 | /* Fill in the offsets for the registers which float_mask says | |
364 | were saved. */ | |
365 | ||
366 | reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc); | |
367 | mask = PROC_FREG_MASK (proc_desc); | |
368 | ||
c5aa993b | 369 | for (ireg = 0; ireg <= 31; ++ireg) |
c906108c SS |
370 | if (mask & (1 << ireg)) |
371 | { | |
c5aa993b | 372 | frame->saved_regs[FP0_REGNUM + ireg] = reg_position; |
c906108c SS |
373 | reg_position += 8; |
374 | } | |
375 | ||
376 | frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg]; | |
377 | } | |
378 | ||
379 | static CORE_ADDR | |
fba45db2 | 380 | read_next_frame_reg (struct frame_info *fi, int regno) |
c906108c SS |
381 | { |
382 | for (; fi; fi = fi->next) | |
383 | { | |
384 | /* We have to get the saved sp from the sigcontext | |
c5aa993b | 385 | if it is a signal handler frame. */ |
c906108c SS |
386 | if (regno == SP_REGNUM && !fi->signal_handler_caller) |
387 | return fi->frame; | |
388 | else | |
389 | { | |
390 | if (fi->saved_regs == NULL) | |
391 | alpha_find_saved_regs (fi); | |
392 | if (fi->saved_regs[regno]) | |
c5aa993b | 393 | return read_memory_integer (fi->saved_regs[regno], 8); |
c906108c SS |
394 | } |
395 | } | |
c5aa993b | 396 | return read_register (regno); |
c906108c SS |
397 | } |
398 | ||
399 | CORE_ADDR | |
fba45db2 | 400 | alpha_frame_saved_pc (struct frame_info *frame) |
c906108c SS |
401 | { |
402 | alpha_extra_func_info_t proc_desc = frame->proc_desc; | |
403 | /* We have to get the saved pc from the sigcontext | |
404 | if it is a signal handler frame. */ | |
405 | int pcreg = frame->signal_handler_caller ? PC_REGNUM : frame->pc_reg; | |
406 | ||
c5aa993b JM |
407 | if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc)) |
408 | return read_memory_integer (frame->frame - 8, 8); | |
c906108c | 409 | |
c5aa993b | 410 | return read_next_frame_reg (frame, pcreg); |
c906108c SS |
411 | } |
412 | ||
413 | CORE_ADDR | |
fba45db2 | 414 | alpha_saved_pc_after_call (struct frame_info *frame) |
c906108c SS |
415 | { |
416 | CORE_ADDR pc = frame->pc; | |
417 | CORE_ADDR tmp; | |
418 | alpha_extra_func_info_t proc_desc; | |
419 | int pcreg; | |
420 | ||
421 | /* Skip over shared library trampoline if necessary. */ | |
422 | tmp = SKIP_TRAMPOLINE_CODE (pc); | |
423 | if (tmp != 0) | |
424 | pc = tmp; | |
425 | ||
426 | proc_desc = find_proc_desc (pc, frame->next); | |
427 | pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM; | |
428 | ||
429 | if (frame->signal_handler_caller) | |
430 | return alpha_frame_saved_pc (frame); | |
431 | else | |
432 | return read_register (pcreg); | |
433 | } | |
434 | ||
435 | ||
436 | static struct alpha_extra_func_info temp_proc_desc; | |
437 | static struct frame_saved_regs temp_saved_regs; | |
438 | ||
439 | /* Nonzero if instruction at PC is a return instruction. "ret | |
440 | $zero,($ra),1" on alpha. */ | |
441 | ||
442 | static int | |
fba45db2 | 443 | alpha_about_to_return (CORE_ADDR pc) |
c906108c SS |
444 | { |
445 | return read_memory_integer (pc, 4) == 0x6bfa8001; | |
446 | } | |
447 | ||
448 | ||
449 | ||
450 | /* This fencepost looks highly suspicious to me. Removing it also | |
451 | seems suspicious as it could affect remote debugging across serial | |
452 | lines. */ | |
453 | ||
454 | static CORE_ADDR | |
fba45db2 | 455 | heuristic_proc_start (CORE_ADDR pc) |
c906108c | 456 | { |
c5aa993b JM |
457 | CORE_ADDR start_pc = pc; |
458 | CORE_ADDR fence = start_pc - heuristic_fence_post; | |
c906108c | 459 | |
c5aa993b JM |
460 | if (start_pc == 0) |
461 | return 0; | |
c906108c | 462 | |
c5aa993b JM |
463 | if (heuristic_fence_post == UINT_MAX |
464 | || fence < VM_MIN_ADDRESS) | |
465 | fence = VM_MIN_ADDRESS; | |
c906108c | 466 | |
c5aa993b JM |
467 | /* search back for previous return */ |
468 | for (start_pc -= 4;; start_pc -= 4) | |
469 | if (start_pc < fence) | |
470 | { | |
471 | /* It's not clear to me why we reach this point when | |
472 | stop_soon_quietly, but with this test, at least we | |
473 | don't print out warnings for every child forked (eg, on | |
474 | decstation). 22apr93 rich@cygnus.com. */ | |
475 | if (!stop_soon_quietly) | |
c906108c | 476 | { |
c5aa993b JM |
477 | static int blurb_printed = 0; |
478 | ||
479 | if (fence == VM_MIN_ADDRESS) | |
480 | warning ("Hit beginning of text section without finding"); | |
481 | else | |
482 | warning ("Hit heuristic-fence-post without finding"); | |
483 | ||
d4f3574e | 484 | warning ("enclosing function for address 0x%s", paddr_nz (pc)); |
c5aa993b | 485 | if (!blurb_printed) |
c906108c | 486 | { |
c5aa993b | 487 | printf_filtered ("\ |
c906108c SS |
488 | This warning occurs if you are debugging a function without any symbols\n\ |
489 | (for example, in a stripped executable). In that case, you may wish to\n\ | |
490 | increase the size of the search with the `set heuristic-fence-post' command.\n\ | |
491 | \n\ | |
492 | Otherwise, you told GDB there was a function where there isn't one, or\n\ | |
493 | (more likely) you have encountered a bug in GDB.\n"); | |
c5aa993b | 494 | blurb_printed = 1; |
c906108c | 495 | } |
c906108c | 496 | } |
c906108c | 497 | |
c5aa993b JM |
498 | return 0; |
499 | } | |
500 | else if (alpha_about_to_return (start_pc)) | |
501 | break; | |
502 | ||
503 | start_pc += 4; /* skip return */ | |
504 | return start_pc; | |
c906108c SS |
505 | } |
506 | ||
507 | static alpha_extra_func_info_t | |
fba45db2 KB |
508 | heuristic_proc_desc (CORE_ADDR start_pc, CORE_ADDR limit_pc, |
509 | struct frame_info *next_frame) | |
c906108c | 510 | { |
c5aa993b JM |
511 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); |
512 | CORE_ADDR cur_pc; | |
513 | int frame_size; | |
514 | int has_frame_reg = 0; | |
515 | unsigned long reg_mask = 0; | |
516 | int pcreg = -1; | |
517 | ||
518 | if (start_pc == 0) | |
519 | return NULL; | |
520 | memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc)); | |
521 | memset (&temp_saved_regs, '\0', sizeof (struct frame_saved_regs)); | |
522 | PROC_LOW_ADDR (&temp_proc_desc) = start_pc; | |
523 | ||
524 | if (start_pc + 200 < limit_pc) | |
525 | limit_pc = start_pc + 200; | |
526 | frame_size = 0; | |
527 | for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) | |
528 | { | |
529 | char buf[4]; | |
530 | unsigned long word; | |
531 | int status; | |
c906108c | 532 | |
c5aa993b JM |
533 | status = read_memory_nobpt (cur_pc, buf, 4); |
534 | if (status) | |
535 | memory_error (status, cur_pc); | |
536 | word = extract_unsigned_integer (buf, 4); | |
c906108c | 537 | |
c5aa993b JM |
538 | if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ |
539 | { | |
540 | if (word & 0x8000) | |
541 | frame_size += (-word) & 0xffff; | |
542 | else | |
543 | /* Exit loop if a positive stack adjustment is found, which | |
544 | usually means that the stack cleanup code in the function | |
545 | epilogue is reached. */ | |
546 | break; | |
547 | } | |
548 | else if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ | |
549 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
550 | { | |
551 | int reg = (word & 0x03e00000) >> 21; | |
552 | reg_mask |= 1 << reg; | |
553 | temp_saved_regs.regs[reg] = sp + (short) word; | |
554 | ||
555 | /* Starting with OSF/1-3.2C, the system libraries are shipped | |
556 | without local symbols, but they still contain procedure | |
557 | descriptors without a symbol reference. GDB is currently | |
558 | unable to find these procedure descriptors and uses | |
559 | heuristic_proc_desc instead. | |
560 | As some low level compiler support routines (__div*, __add*) | |
561 | use a non-standard return address register, we have to | |
562 | add some heuristics to determine the return address register, | |
563 | or stepping over these routines will fail. | |
564 | Usually the return address register is the first register | |
565 | saved on the stack, but assembler optimization might | |
566 | rearrange the register saves. | |
567 | So we recognize only a few registers (t7, t9, ra) within | |
568 | the procedure prologue as valid return address registers. | |
569 | If we encounter a return instruction, we extract the | |
570 | the return address register from it. | |
571 | ||
572 | FIXME: Rewriting GDB to access the procedure descriptors, | |
573 | e.g. via the minimal symbol table, might obviate this hack. */ | |
574 | if (pcreg == -1 | |
575 | && cur_pc < (start_pc + 80) | |
576 | && (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)) | |
577 | pcreg = reg; | |
578 | } | |
579 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
580 | pcreg = (word >> 16) & 0x1f; | |
581 | else if (word == 0x47de040f) /* bis sp,sp fp */ | |
582 | has_frame_reg = 1; | |
583 | } | |
584 | if (pcreg == -1) | |
585 | { | |
586 | /* If we haven't found a valid return address register yet, | |
587 | keep searching in the procedure prologue. */ | |
588 | while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80)) | |
589 | { | |
590 | char buf[4]; | |
591 | unsigned long word; | |
c906108c | 592 | |
c5aa993b JM |
593 | if (read_memory_nobpt (cur_pc, buf, 4)) |
594 | break; | |
595 | cur_pc += 4; | |
596 | word = extract_unsigned_integer (buf, 4); | |
c906108c | 597 | |
c5aa993b JM |
598 | if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ |
599 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
600 | { | |
601 | int reg = (word & 0x03e00000) >> 21; | |
602 | if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM) | |
603 | { | |
604 | pcreg = reg; | |
605 | break; | |
606 | } | |
607 | } | |
608 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
609 | { | |
610 | pcreg = (word >> 16) & 0x1f; | |
611 | break; | |
612 | } | |
613 | } | |
614 | } | |
c906108c | 615 | |
c5aa993b JM |
616 | if (has_frame_reg) |
617 | PROC_FRAME_REG (&temp_proc_desc) = GCC_FP_REGNUM; | |
618 | else | |
619 | PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM; | |
620 | PROC_FRAME_OFFSET (&temp_proc_desc) = frame_size; | |
621 | PROC_REG_MASK (&temp_proc_desc) = reg_mask; | |
622 | PROC_PC_REG (&temp_proc_desc) = (pcreg == -1) ? RA_REGNUM : pcreg; | |
623 | PROC_LOCALOFF (&temp_proc_desc) = 0; /* XXX - bogus */ | |
624 | return &temp_proc_desc; | |
c906108c SS |
625 | } |
626 | ||
627 | /* This returns the PC of the first inst after the prologue. If we can't | |
628 | find the prologue, then return 0. */ | |
629 | ||
630 | static CORE_ADDR | |
fba45db2 | 631 | after_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) |
c906108c SS |
632 | { |
633 | struct symtab_and_line sal; | |
634 | CORE_ADDR func_addr, func_end; | |
635 | ||
636 | if (!proc_desc) | |
637 | proc_desc = find_proc_desc (pc, NULL); | |
638 | ||
639 | if (proc_desc) | |
640 | { | |
641 | if (PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)) | |
642 | return PROC_LOW_ADDR (proc_desc); /* "prologue" is in kernel */ | |
643 | ||
644 | /* If function is frameless, then we need to do it the hard way. I | |
c5aa993b | 645 | strongly suspect that frameless always means prologueless... */ |
c906108c SS |
646 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM |
647 | && PROC_FRAME_OFFSET (proc_desc) == 0) | |
648 | return 0; | |
649 | } | |
650 | ||
651 | if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
652 | return 0; /* Unknown */ | |
653 | ||
654 | sal = find_pc_line (func_addr, 0); | |
655 | ||
656 | if (sal.end < func_end) | |
657 | return sal.end; | |
658 | ||
659 | /* The line after the prologue is after the end of the function. In this | |
660 | case, tell the caller to find the prologue the hard way. */ | |
661 | ||
662 | return 0; | |
663 | } | |
664 | ||
665 | /* Return non-zero if we *might* be in a function prologue. Return zero if we | |
666 | are definitively *not* in a function prologue. */ | |
667 | ||
668 | static int | |
fba45db2 | 669 | alpha_in_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) |
c906108c SS |
670 | { |
671 | CORE_ADDR after_prologue_pc; | |
672 | ||
673 | after_prologue_pc = after_prologue (pc, proc_desc); | |
674 | ||
675 | if (after_prologue_pc == 0 | |
676 | || pc < after_prologue_pc) | |
677 | return 1; | |
678 | else | |
679 | return 0; | |
680 | } | |
681 | ||
682 | static alpha_extra_func_info_t | |
fba45db2 | 683 | find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame) |
c906108c SS |
684 | { |
685 | alpha_extra_func_info_t proc_desc; | |
686 | struct block *b; | |
687 | struct symbol *sym; | |
688 | CORE_ADDR startaddr; | |
689 | ||
690 | /* Try to get the proc_desc from the linked call dummy proc_descs | |
691 | if the pc is in the call dummy. | |
692 | This is hairy. In the case of nested dummy calls we have to find the | |
693 | right proc_desc, but we might not yet know the frame for the dummy | |
694 | as it will be contained in the proc_desc we are searching for. | |
695 | So we have to find the proc_desc whose frame is closest to the current | |
696 | stack pointer. */ | |
697 | ||
698 | if (PC_IN_CALL_DUMMY (pc, 0, 0)) | |
699 | { | |
700 | struct linked_proc_info *link; | |
701 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); | |
702 | alpha_extra_func_info_t found_proc_desc = NULL; | |
703 | long min_distance = LONG_MAX; | |
704 | ||
705 | for (link = linked_proc_desc_table; link; link = link->next) | |
706 | { | |
707 | long distance = (CORE_ADDR) PROC_DUMMY_FRAME (&link->info) - sp; | |
708 | if (distance > 0 && distance < min_distance) | |
709 | { | |
710 | min_distance = distance; | |
711 | found_proc_desc = &link->info; | |
712 | } | |
713 | } | |
714 | if (found_proc_desc != NULL) | |
715 | return found_proc_desc; | |
716 | } | |
717 | ||
c5aa993b | 718 | b = block_for_pc (pc); |
c906108c SS |
719 | |
720 | find_pc_partial_function (pc, NULL, &startaddr, NULL); | |
721 | if (b == NULL) | |
722 | sym = NULL; | |
723 | else | |
724 | { | |
725 | if (startaddr > BLOCK_START (b)) | |
726 | /* This is the "pathological" case referred to in a comment in | |
727 | print_frame_info. It might be better to move this check into | |
728 | symbol reading. */ | |
729 | sym = NULL; | |
730 | else | |
731 | sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, | |
732 | 0, NULL); | |
733 | } | |
734 | ||
735 | /* If we never found a PDR for this function in symbol reading, then | |
736 | examine prologues to find the information. */ | |
737 | if (sym && ((mips_extra_func_info_t) SYMBOL_VALUE (sym))->pdr.framereg == -1) | |
738 | sym = NULL; | |
739 | ||
740 | if (sym) | |
741 | { | |
c5aa993b JM |
742 | /* IF this is the topmost frame AND |
743 | * (this proc does not have debugging information OR | |
744 | * the PC is in the procedure prologue) | |
745 | * THEN create a "heuristic" proc_desc (by analyzing | |
746 | * the actual code) to replace the "official" proc_desc. | |
747 | */ | |
748 | proc_desc = (alpha_extra_func_info_t) SYMBOL_VALUE (sym); | |
749 | if (next_frame == NULL) | |
750 | { | |
751 | if (PROC_DESC_IS_DUMMY (proc_desc) || alpha_in_prologue (pc, proc_desc)) | |
752 | { | |
753 | alpha_extra_func_info_t found_heuristic = | |
754 | heuristic_proc_desc (PROC_LOW_ADDR (proc_desc), | |
755 | pc, next_frame); | |
756 | if (found_heuristic) | |
757 | { | |
758 | PROC_LOCALOFF (found_heuristic) = | |
759 | PROC_LOCALOFF (proc_desc); | |
760 | PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc); | |
761 | proc_desc = found_heuristic; | |
762 | } | |
763 | } | |
764 | } | |
c906108c SS |
765 | } |
766 | else | |
767 | { | |
768 | long offset; | |
769 | ||
770 | /* Is linked_proc_desc_table really necessary? It only seems to be used | |
c5aa993b JM |
771 | by procedure call dummys. However, the procedures being called ought |
772 | to have their own proc_descs, and even if they don't, | |
773 | heuristic_proc_desc knows how to create them! */ | |
c906108c SS |
774 | |
775 | register struct linked_proc_info *link; | |
776 | for (link = linked_proc_desc_table; link; link = link->next) | |
c5aa993b JM |
777 | if (PROC_LOW_ADDR (&link->info) <= pc |
778 | && PROC_HIGH_ADDR (&link->info) > pc) | |
779 | return &link->info; | |
c906108c SS |
780 | |
781 | /* If PC is inside a dynamically generated sigtramp handler, | |
c5aa993b | 782 | create and push a procedure descriptor for that code: */ |
c906108c SS |
783 | offset = DYNAMIC_SIGTRAMP_OFFSET (pc); |
784 | if (offset >= 0) | |
785 | return push_sigtramp_desc (pc - offset); | |
786 | ||
787 | /* If heuristic_fence_post is non-zero, determine the procedure | |
c5aa993b JM |
788 | start address by examining the instructions. |
789 | This allows us to find the start address of static functions which | |
790 | have no symbolic information, as startaddr would have been set to | |
791 | the preceding global function start address by the | |
792 | find_pc_partial_function call above. */ | |
c906108c SS |
793 | if (startaddr == 0 || heuristic_fence_post != 0) |
794 | startaddr = heuristic_proc_start (pc); | |
795 | ||
796 | proc_desc = | |
797 | heuristic_proc_desc (startaddr, pc, next_frame); | |
798 | } | |
799 | return proc_desc; | |
800 | } | |
801 | ||
802 | alpha_extra_func_info_t cached_proc_desc; | |
803 | ||
804 | CORE_ADDR | |
fba45db2 | 805 | alpha_frame_chain (struct frame_info *frame) |
c906108c | 806 | { |
c5aa993b JM |
807 | alpha_extra_func_info_t proc_desc; |
808 | CORE_ADDR saved_pc = FRAME_SAVED_PC (frame); | |
809 | ||
810 | if (saved_pc == 0 || inside_entry_file (saved_pc)) | |
811 | return 0; | |
812 | ||
813 | proc_desc = find_proc_desc (saved_pc, frame); | |
814 | if (!proc_desc) | |
815 | return 0; | |
816 | ||
817 | cached_proc_desc = proc_desc; | |
818 | ||
819 | /* Fetch the frame pointer for a dummy frame from the procedure | |
820 | descriptor. */ | |
821 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
822 | return (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc); | |
823 | ||
824 | /* If no frame pointer and frame size is zero, we must be at end | |
825 | of stack (or otherwise hosed). If we don't check frame size, | |
826 | we loop forever if we see a zero size frame. */ | |
827 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM | |
828 | && PROC_FRAME_OFFSET (proc_desc) == 0 | |
829 | /* The previous frame from a sigtramp frame might be frameless | |
830 | and have frame size zero. */ | |
831 | && !frame->signal_handler_caller) | |
832 | return FRAME_PAST_SIGTRAMP_FRAME (frame, saved_pc); | |
833 | else | |
834 | return read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc)) | |
835 | + PROC_FRAME_OFFSET (proc_desc); | |
c906108c SS |
836 | } |
837 | ||
838 | void | |
fba45db2 | 839 | init_extra_frame_info (struct frame_info *frame) |
c906108c SS |
840 | { |
841 | /* Use proc_desc calculated in frame_chain */ | |
842 | alpha_extra_func_info_t proc_desc = | |
c5aa993b | 843 | frame->next ? cached_proc_desc : find_proc_desc (frame->pc, frame->next); |
c906108c SS |
844 | |
845 | frame->saved_regs = NULL; | |
846 | frame->localoff = 0; | |
847 | frame->pc_reg = RA_REGNUM; | |
848 | frame->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc; | |
849 | if (proc_desc) | |
850 | { | |
851 | /* Get the locals offset and the saved pc register from the | |
c5aa993b JM |
852 | procedure descriptor, they are valid even if we are in the |
853 | middle of the prologue. */ | |
854 | frame->localoff = PROC_LOCALOFF (proc_desc); | |
855 | frame->pc_reg = PROC_PC_REG (proc_desc); | |
c906108c SS |
856 | |
857 | /* Fixup frame-pointer - only needed for top frame */ | |
858 | ||
859 | /* Fetch the frame pointer for a dummy frame from the procedure | |
c5aa993b JM |
860 | descriptor. */ |
861 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
862 | frame->frame = (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc); | |
c906108c SS |
863 | |
864 | /* This may not be quite right, if proc has a real frame register. | |
c5aa993b JM |
865 | Get the value of the frame relative sp, procedure might have been |
866 | interrupted by a signal at it's very start. */ | |
c906108c SS |
867 | else if (frame->pc == PROC_LOW_ADDR (proc_desc) |
868 | && !PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)) | |
869 | frame->frame = read_next_frame_reg (frame->next, SP_REGNUM); | |
870 | else | |
871 | frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc)) | |
872 | + PROC_FRAME_OFFSET (proc_desc); | |
873 | ||
874 | if (proc_desc == &temp_proc_desc) | |
875 | { | |
876 | char *name; | |
877 | ||
878 | /* Do not set the saved registers for a sigtramp frame, | |
879 | alpha_find_saved_registers will do that for us. | |
880 | We can't use frame->signal_handler_caller, it is not yet set. */ | |
881 | find_pc_partial_function (frame->pc, &name, | |
c5aa993b | 882 | (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
c906108c SS |
883 | if (!IN_SIGTRAMP (frame->pc, name)) |
884 | { | |
c5aa993b | 885 | frame->saved_regs = (CORE_ADDR *) |
c906108c SS |
886 | frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS); |
887 | memcpy (frame->saved_regs, temp_saved_regs.regs, SIZEOF_FRAME_SAVED_REGS); | |
888 | frame->saved_regs[PC_REGNUM] | |
889 | = frame->saved_regs[RA_REGNUM]; | |
890 | } | |
891 | } | |
892 | } | |
893 | } | |
894 | ||
895 | /* ALPHA stack frames are almost impenetrable. When execution stops, | |
896 | we basically have to look at symbol information for the function | |
897 | that we stopped in, which tells us *which* register (if any) is | |
898 | the base of the frame pointer, and what offset from that register | |
899 | the frame itself is at. | |
900 | ||
901 | This presents a problem when trying to examine a stack in memory | |
902 | (that isn't executing at the moment), using the "frame" command. We | |
903 | don't have a PC, nor do we have any registers except SP. | |
904 | ||
905 | This routine takes two arguments, SP and PC, and tries to make the | |
906 | cached frames look as if these two arguments defined a frame on the | |
907 | cache. This allows the rest of info frame to extract the important | |
908 | arguments without difficulty. */ | |
909 | ||
910 | struct frame_info * | |
fba45db2 | 911 | setup_arbitrary_frame (int argc, CORE_ADDR *argv) |
c906108c SS |
912 | { |
913 | if (argc != 2) | |
914 | error ("ALPHA frame specifications require two arguments: sp and pc"); | |
915 | ||
916 | return create_new_frame (argv[0], argv[1]); | |
917 | } | |
918 | ||
919 | /* The alpha passes the first six arguments in the registers, the rest on | |
920 | the stack. The register arguments are eventually transferred to the | |
921 | argument transfer area immediately below the stack by the called function | |
922 | anyway. So we `push' at least six arguments on the stack, `reload' the | |
923 | argument registers and then adjust the stack pointer to point past the | |
924 | sixth argument. This algorithm simplifies the passing of a large struct | |
925 | which extends from the registers to the stack. | |
926 | If the called function is returning a structure, the address of the | |
927 | structure to be returned is passed as a hidden first argument. */ | |
928 | ||
929 | CORE_ADDR | |
ea7c478f | 930 | alpha_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
fba45db2 | 931 | int struct_return, CORE_ADDR struct_addr) |
c906108c | 932 | { |
7a292a7a | 933 | int i; |
c906108c SS |
934 | int accumulate_size = struct_return ? 8 : 0; |
935 | int arg_regs_size = ALPHA_NUM_ARG_REGS * 8; | |
c5aa993b JM |
936 | struct alpha_arg |
937 | { | |
938 | char *contents; | |
939 | int len; | |
940 | int offset; | |
941 | }; | |
c906108c | 942 | struct alpha_arg *alpha_args = |
c5aa993b | 943 | (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg)); |
c906108c SS |
944 | register struct alpha_arg *m_arg; |
945 | char raw_buffer[sizeof (CORE_ADDR)]; | |
946 | int required_arg_regs; | |
947 | ||
948 | for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++) | |
949 | { | |
ea7c478f | 950 | struct value *arg = args[i]; |
c906108c SS |
951 | struct type *arg_type = check_typedef (VALUE_TYPE (arg)); |
952 | /* Cast argument to long if necessary as the compiler does it too. */ | |
953 | switch (TYPE_CODE (arg_type)) | |
954 | { | |
955 | case TYPE_CODE_INT: | |
956 | case TYPE_CODE_BOOL: | |
957 | case TYPE_CODE_CHAR: | |
958 | case TYPE_CODE_RANGE: | |
959 | case TYPE_CODE_ENUM: | |
960 | if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long)) | |
961 | { | |
962 | arg_type = builtin_type_long; | |
963 | arg = value_cast (arg_type, arg); | |
964 | } | |
965 | break; | |
966 | default: | |
967 | break; | |
968 | } | |
969 | m_arg->len = TYPE_LENGTH (arg_type); | |
970 | m_arg->offset = accumulate_size; | |
971 | accumulate_size = (accumulate_size + m_arg->len + 7) & ~7; | |
c5aa993b | 972 | m_arg->contents = VALUE_CONTENTS (arg); |
c906108c SS |
973 | } |
974 | ||
975 | /* Determine required argument register loads, loading an argument register | |
976 | is expensive as it uses three ptrace calls. */ | |
977 | required_arg_regs = accumulate_size / 8; | |
978 | if (required_arg_regs > ALPHA_NUM_ARG_REGS) | |
979 | required_arg_regs = ALPHA_NUM_ARG_REGS; | |
980 | ||
981 | /* Make room for the arguments on the stack. */ | |
982 | if (accumulate_size < arg_regs_size) | |
c5aa993b | 983 | accumulate_size = arg_regs_size; |
c906108c SS |
984 | sp -= accumulate_size; |
985 | ||
986 | /* Keep sp aligned to a multiple of 16 as the compiler does it too. */ | |
987 | sp &= ~15; | |
988 | ||
989 | /* `Push' arguments on the stack. */ | |
c5aa993b JM |
990 | for (i = nargs; m_arg--, --i >= 0;) |
991 | write_memory (sp + m_arg->offset, m_arg->contents, m_arg->len); | |
c906108c SS |
992 | if (struct_return) |
993 | { | |
994 | store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr); | |
995 | write_memory (sp, raw_buffer, sizeof (CORE_ADDR)); | |
996 | } | |
997 | ||
998 | /* Load the argument registers. */ | |
999 | for (i = 0; i < required_arg_regs; i++) | |
1000 | { | |
1001 | LONGEST val; | |
1002 | ||
1003 | val = read_memory_integer (sp + i * 8, 8); | |
1004 | write_register (A0_REGNUM + i, val); | |
1005 | write_register (FPA0_REGNUM + i, val); | |
1006 | } | |
1007 | ||
1008 | return sp + arg_regs_size; | |
1009 | } | |
1010 | ||
1011 | void | |
fba45db2 | 1012 | alpha_push_dummy_frame (void) |
c906108c SS |
1013 | { |
1014 | int ireg; | |
1015 | struct linked_proc_info *link; | |
1016 | alpha_extra_func_info_t proc_desc; | |
1017 | CORE_ADDR sp = read_register (SP_REGNUM); | |
1018 | CORE_ADDR save_address; | |
1019 | char raw_buffer[MAX_REGISTER_RAW_SIZE]; | |
1020 | unsigned long mask; | |
1021 | ||
c5aa993b | 1022 | link = (struct linked_proc_info *) xmalloc (sizeof (struct linked_proc_info)); |
c906108c SS |
1023 | link->next = linked_proc_desc_table; |
1024 | linked_proc_desc_table = link; | |
c5aa993b | 1025 | |
c906108c SS |
1026 | proc_desc = &link->info; |
1027 | ||
1028 | /* | |
1029 | * The registers we must save are all those not preserved across | |
1030 | * procedure calls. | |
1031 | * In addition, we must save the PC and RA. | |
1032 | * | |
1033 | * Dummy frame layout: | |
1034 | * (high memory) | |
c5aa993b | 1035 | * Saved PC |
c906108c SS |
1036 | * Saved F30 |
1037 | * ... | |
1038 | * Saved F0 | |
c5aa993b JM |
1039 | * Saved R29 |
1040 | * ... | |
1041 | * Saved R0 | |
1042 | * Saved R26 (RA) | |
1043 | * Parameter build area | |
c906108c SS |
1044 | * (low memory) |
1045 | */ | |
1046 | ||
1047 | /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */ | |
1048 | #define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1)) | |
1049 | #define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29)) | |
1050 | #define GEN_REG_SAVE_COUNT 24 | |
1051 | #define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30)) | |
1052 | #define FLOAT_REG_SAVE_COUNT 23 | |
1053 | /* The special register is the PC as we have no bit for it in the save masks. | |
1054 | alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */ | |
1055 | #define SPECIAL_REG_SAVE_COUNT 1 | |
1056 | ||
c5aa993b JM |
1057 | PROC_REG_MASK (proc_desc) = GEN_REG_SAVE_MASK; |
1058 | PROC_FREG_MASK (proc_desc) = FLOAT_REG_SAVE_MASK; | |
c906108c SS |
1059 | /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA, |
1060 | but keep SP aligned to a multiple of 16. */ | |
c5aa993b JM |
1061 | PROC_REG_OFFSET (proc_desc) = |
1062 | -((8 * (SPECIAL_REG_SAVE_COUNT | |
c906108c SS |
1063 | + GEN_REG_SAVE_COUNT |
1064 | + FLOAT_REG_SAVE_COUNT) | |
c5aa993b JM |
1065 | + 15) & ~15); |
1066 | PROC_FREG_OFFSET (proc_desc) = | |
1067 | PROC_REG_OFFSET (proc_desc) + 8 * GEN_REG_SAVE_COUNT; | |
c906108c SS |
1068 | |
1069 | /* Save general registers. | |
1070 | The return address register is the first saved register, all other | |
1071 | registers follow in ascending order. | |
1072 | The PC is saved immediately below the SP. */ | |
c5aa993b | 1073 | save_address = sp + PROC_REG_OFFSET (proc_desc); |
c906108c SS |
1074 | store_address (raw_buffer, 8, read_register (RA_REGNUM)); |
1075 | write_memory (save_address, raw_buffer, 8); | |
1076 | save_address += 8; | |
c5aa993b | 1077 | mask = PROC_REG_MASK (proc_desc) & 0xffffffffL; |
c906108c SS |
1078 | for (ireg = 0; mask; ireg++, mask >>= 1) |
1079 | if (mask & 1) | |
1080 | { | |
1081 | if (ireg == RA_REGNUM) | |
1082 | continue; | |
1083 | store_address (raw_buffer, 8, read_register (ireg)); | |
1084 | write_memory (save_address, raw_buffer, 8); | |
1085 | save_address += 8; | |
1086 | } | |
1087 | ||
1088 | store_address (raw_buffer, 8, read_register (PC_REGNUM)); | |
1089 | write_memory (sp - 8, raw_buffer, 8); | |
1090 | ||
1091 | /* Save floating point registers. */ | |
c5aa993b JM |
1092 | save_address = sp + PROC_FREG_OFFSET (proc_desc); |
1093 | mask = PROC_FREG_MASK (proc_desc) & 0xffffffffL; | |
c906108c SS |
1094 | for (ireg = 0; mask; ireg++, mask >>= 1) |
1095 | if (mask & 1) | |
1096 | { | |
1097 | store_address (raw_buffer, 8, read_register (ireg + FP0_REGNUM)); | |
1098 | write_memory (save_address, raw_buffer, 8); | |
1099 | save_address += 8; | |
1100 | } | |
1101 | ||
1102 | /* Set and save the frame address for the dummy. | |
1103 | This is tricky. The only registers that are suitable for a frame save | |
1104 | are those that are preserved across procedure calls (s0-s6). But if | |
1105 | a read system call is interrupted and then a dummy call is made | |
1106 | (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read | |
1107 | is satisfied. Then it returns with the s0-s6 registers set to the values | |
1108 | on entry to the read system call and our dummy frame pointer would be | |
1109 | destroyed. So we save the dummy frame in the proc_desc and handle the | |
1110 | retrieval of the frame pointer of a dummy specifically. The frame register | |
1111 | is set to the virtual frame (pseudo) register, it's value will always | |
1112 | be read as zero and will help us to catch any errors in the dummy frame | |
1113 | retrieval code. */ | |
c5aa993b JM |
1114 | PROC_DUMMY_FRAME (proc_desc) = sp; |
1115 | PROC_FRAME_REG (proc_desc) = FP_REGNUM; | |
1116 | PROC_FRAME_OFFSET (proc_desc) = 0; | |
1117 | sp += PROC_REG_OFFSET (proc_desc); | |
c906108c SS |
1118 | write_register (SP_REGNUM, sp); |
1119 | ||
c5aa993b JM |
1120 | PROC_LOW_ADDR (proc_desc) = CALL_DUMMY_ADDRESS (); |
1121 | PROC_HIGH_ADDR (proc_desc) = PROC_LOW_ADDR (proc_desc) + 4; | |
c906108c | 1122 | |
c5aa993b JM |
1123 | SET_PROC_DESC_IS_DUMMY (proc_desc); |
1124 | PROC_PC_REG (proc_desc) = RA_REGNUM; | |
c906108c SS |
1125 | } |
1126 | ||
1127 | void | |
fba45db2 | 1128 | alpha_pop_frame (void) |
c906108c SS |
1129 | { |
1130 | register int regnum; | |
1131 | struct frame_info *frame = get_current_frame (); | |
1132 | CORE_ADDR new_sp = frame->frame; | |
1133 | ||
1134 | alpha_extra_func_info_t proc_desc = frame->proc_desc; | |
1135 | ||
9e0b60a8 JM |
1136 | /* we need proc_desc to know how to restore the registers; |
1137 | if it is NULL, construct (a temporary) one */ | |
1138 | if (proc_desc == NULL) | |
c5aa993b | 1139 | proc_desc = find_proc_desc (frame->pc, frame->next); |
9e0b60a8 JM |
1140 | |
1141 | /* Question: should we copy this proc_desc and save it in | |
1142 | frame->proc_desc? If we do, who will free it? | |
1143 | For now, we don't save a copy... */ | |
1144 | ||
c5aa993b | 1145 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
c906108c SS |
1146 | if (frame->saved_regs == NULL) |
1147 | alpha_find_saved_regs (frame); | |
1148 | if (proc_desc) | |
1149 | { | |
c5aa993b JM |
1150 | for (regnum = 32; --regnum >= 0;) |
1151 | if (PROC_REG_MASK (proc_desc) & (1 << regnum)) | |
c906108c SS |
1152 | write_register (regnum, |
1153 | read_memory_integer (frame->saved_regs[regnum], | |
1154 | 8)); | |
c5aa993b JM |
1155 | for (regnum = 32; --regnum >= 0;) |
1156 | if (PROC_FREG_MASK (proc_desc) & (1 << regnum)) | |
c906108c | 1157 | write_register (regnum + FP0_REGNUM, |
c5aa993b | 1158 | read_memory_integer (frame->saved_regs[regnum + FP0_REGNUM], 8)); |
c906108c SS |
1159 | } |
1160 | write_register (SP_REGNUM, new_sp); | |
1161 | flush_cached_frames (); | |
1162 | ||
c5aa993b | 1163 | if (proc_desc && (PROC_DESC_IS_DUMMY (proc_desc) |
c906108c SS |
1164 | || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))) |
1165 | { | |
1166 | struct linked_proc_info *pi_ptr, *prev_ptr; | |
1167 | ||
1168 | for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL; | |
1169 | pi_ptr != NULL; | |
1170 | prev_ptr = pi_ptr, pi_ptr = pi_ptr->next) | |
1171 | { | |
1172 | if (&pi_ptr->info == proc_desc) | |
1173 | break; | |
1174 | } | |
1175 | ||
1176 | if (pi_ptr == NULL) | |
1177 | error ("Can't locate dummy extra frame info\n"); | |
1178 | ||
1179 | if (prev_ptr != NULL) | |
1180 | prev_ptr->next = pi_ptr->next; | |
1181 | else | |
1182 | linked_proc_desc_table = pi_ptr->next; | |
1183 | ||
b8c9b27d | 1184 | xfree (pi_ptr); |
c906108c SS |
1185 | } |
1186 | } | |
1187 | \f | |
1188 | /* To skip prologues, I use this predicate. Returns either PC itself | |
1189 | if the code at PC does not look like a function prologue; otherwise | |
1190 | returns an address that (if we're lucky) follows the prologue. If | |
1191 | LENIENT, then we must skip everything which is involved in setting | |
1192 | up the frame (it's OK to skip more, just so long as we don't skip | |
1193 | anything which might clobber the registers which are being saved. | |
0fb34c3a MS |
1194 | Currently we must not skip more on the alpha, but we might need the |
1195 | lenient stuff some day. */ | |
c906108c SS |
1196 | |
1197 | CORE_ADDR | |
fba45db2 | 1198 | alpha_skip_prologue (CORE_ADDR pc, int lenient) |
c906108c | 1199 | { |
c5aa993b JM |
1200 | unsigned long inst; |
1201 | int offset; | |
1202 | CORE_ADDR post_prologue_pc; | |
1203 | char buf[4]; | |
c906108c SS |
1204 | |
1205 | #ifdef GDB_TARGET_HAS_SHARED_LIBS | |
c5aa993b JM |
1206 | /* Silently return the unaltered pc upon memory errors. |
1207 | This could happen on OSF/1 if decode_line_1 tries to skip the | |
1208 | prologue for quickstarted shared library functions when the | |
1209 | shared library is not yet mapped in. | |
1210 | Reading target memory is slow over serial lines, so we perform | |
1211 | this check only if the target has shared libraries. */ | |
1212 | if (target_read_memory (pc, buf, 4)) | |
1213 | return pc; | |
c906108c SS |
1214 | #endif |
1215 | ||
c5aa993b JM |
1216 | /* See if we can determine the end of the prologue via the symbol table. |
1217 | If so, then return either PC, or the PC after the prologue, whichever | |
1218 | is greater. */ | |
c906108c | 1219 | |
c5aa993b | 1220 | post_prologue_pc = after_prologue (pc, NULL); |
c906108c | 1221 | |
c5aa993b JM |
1222 | if (post_prologue_pc != 0) |
1223 | return max (pc, post_prologue_pc); | |
c906108c | 1224 | |
c5aa993b JM |
1225 | /* Can't determine prologue from the symbol table, need to examine |
1226 | instructions. */ | |
c906108c | 1227 | |
c5aa993b JM |
1228 | /* Skip the typical prologue instructions. These are the stack adjustment |
1229 | instruction and the instructions that save registers on the stack | |
1230 | or in the gcc frame. */ | |
1231 | for (offset = 0; offset < 100; offset += 4) | |
1232 | { | |
1233 | int status; | |
1234 | ||
1235 | status = read_memory_nobpt (pc + offset, buf, 4); | |
1236 | if (status) | |
1237 | memory_error (status, pc + offset); | |
1238 | inst = extract_unsigned_integer (buf, 4); | |
1239 | ||
1240 | /* The alpha has no delay slots. But let's keep the lenient stuff, | |
1241 | we might need it for something else in the future. */ | |
1242 | if (lenient && 0) | |
1243 | continue; | |
1244 | ||
1245 | if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */ | |
1246 | continue; | |
1247 | if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */ | |
1248 | continue; | |
1249 | if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ | |
1250 | continue; | |
1251 | if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */ | |
1252 | continue; | |
1253 | ||
1254 | if ((inst & 0xfc1f0000) == 0xb41e0000 | |
1255 | && (inst & 0xffff0000) != 0xb7fe0000) | |
1256 | continue; /* stq reg,n($sp) */ | |
1257 | /* reg != $zero */ | |
1258 | if ((inst & 0xfc1f0000) == 0x9c1e0000 | |
1259 | && (inst & 0xffff0000) != 0x9ffe0000) | |
1260 | continue; /* stt reg,n($sp) */ | |
1261 | /* reg != $zero */ | |
1262 | if (inst == 0x47de040f) /* bis sp,sp,fp */ | |
1263 | continue; | |
1264 | ||
1265 | break; | |
c906108c | 1266 | } |
c5aa993b | 1267 | return pc + offset; |
c906108c SS |
1268 | } |
1269 | ||
1270 | #if 0 | |
1271 | /* Is address PC in the prologue (loosely defined) for function at | |
1272 | STARTADDR? */ | |
1273 | ||
1274 | static int | |
fba45db2 | 1275 | alpha_in_lenient_prologue (CORE_ADDR startaddr, CORE_ADDR pc) |
c906108c SS |
1276 | { |
1277 | CORE_ADDR end_prologue = alpha_skip_prologue (startaddr, 1); | |
1278 | return pc >= startaddr && pc < end_prologue; | |
1279 | } | |
1280 | #endif | |
1281 | ||
1282 | /* The alpha needs a conversion between register and memory format if | |
1283 | the register is a floating point register and | |
c5aa993b | 1284 | memory format is float, as the register format must be double |
c906108c | 1285 | or |
c5aa993b JM |
1286 | memory format is an integer with 4 bytes or less, as the representation |
1287 | of integers in floating point registers is different. */ | |
c906108c | 1288 | void |
fba45db2 KB |
1289 | alpha_register_convert_to_virtual (int regnum, struct type *valtype, |
1290 | char *raw_buffer, char *virtual_buffer) | |
c906108c SS |
1291 | { |
1292 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1293 | { | |
1294 | memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum)); | |
1295 | return; | |
1296 | } | |
1297 | ||
1298 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1299 | { | |
1300 | double d = extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1301 | store_floating (virtual_buffer, TYPE_LENGTH (valtype), d); | |
1302 | } | |
1303 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1304 | { | |
1305 | ULONGEST l; | |
1306 | l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1307 | l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff); | |
1308 | store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l); | |
1309 | } | |
1310 | else | |
1311 | error ("Cannot retrieve value from floating point register"); | |
1312 | } | |
1313 | ||
1314 | void | |
fba45db2 KB |
1315 | alpha_register_convert_to_raw (struct type *valtype, int regnum, |
1316 | char *virtual_buffer, char *raw_buffer) | |
c906108c SS |
1317 | { |
1318 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1319 | { | |
1320 | memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum)); | |
1321 | return; | |
1322 | } | |
1323 | ||
1324 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1325 | { | |
1326 | double d = extract_floating (virtual_buffer, TYPE_LENGTH (valtype)); | |
1327 | store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d); | |
1328 | } | |
1329 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1330 | { | |
1331 | ULONGEST l; | |
1332 | if (TYPE_UNSIGNED (valtype)) | |
1333 | l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1334 | else | |
1335 | l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1336 | l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29); | |
1337 | store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l); | |
1338 | } | |
1339 | else | |
1340 | error ("Cannot store value in floating point register"); | |
1341 | } | |
1342 | ||
1343 | /* Given a return value in `regbuf' with a type `valtype', | |
1344 | extract and copy its value into `valbuf'. */ | |
1345 | ||
1346 | void | |
732a6b2d KB |
1347 | alpha_extract_return_value (struct type *valtype, |
1348 | char regbuf[REGISTER_BYTES], char *valbuf) | |
c906108c SS |
1349 | { |
1350 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1351 | alpha_register_convert_to_virtual (FP0_REGNUM, valtype, | |
1352 | regbuf + REGISTER_BYTE (FP0_REGNUM), | |
1353 | valbuf); | |
1354 | else | |
1355 | memcpy (valbuf, regbuf + REGISTER_BYTE (V0_REGNUM), TYPE_LENGTH (valtype)); | |
1356 | } | |
1357 | ||
1358 | /* Given a return value in `regbuf' with a type `valtype', | |
1359 | write its value into the appropriate register. */ | |
1360 | ||
1361 | void | |
fba45db2 | 1362 | alpha_store_return_value (struct type *valtype, char *valbuf) |
c906108c SS |
1363 | { |
1364 | char raw_buffer[MAX_REGISTER_RAW_SIZE]; | |
1365 | int regnum = V0_REGNUM; | |
1366 | int length = TYPE_LENGTH (valtype); | |
c5aa993b | 1367 | |
c906108c SS |
1368 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
1369 | { | |
1370 | regnum = FP0_REGNUM; | |
1371 | length = REGISTER_RAW_SIZE (regnum); | |
1372 | alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer); | |
1373 | } | |
1374 | else | |
1375 | memcpy (raw_buffer, valbuf, length); | |
1376 | ||
1377 | write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length); | |
1378 | } | |
1379 | ||
1380 | /* Just like reinit_frame_cache, but with the right arguments to be | |
1381 | callable as an sfunc. */ | |
1382 | ||
1383 | static void | |
fba45db2 | 1384 | reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c) |
c906108c SS |
1385 | { |
1386 | reinit_frame_cache (); | |
1387 | } | |
1388 | ||
1389 | /* This is the definition of CALL_DUMMY_ADDRESS. It's a heuristic that is used | |
1390 | to find a convenient place in the text segment to stick a breakpoint to | |
1391 | detect the completion of a target function call (ala call_function_by_hand). | |
1392 | */ | |
1393 | ||
1394 | CORE_ADDR | |
fba45db2 | 1395 | alpha_call_dummy_address (void) |
c906108c SS |
1396 | { |
1397 | CORE_ADDR entry; | |
1398 | struct minimal_symbol *sym; | |
1399 | ||
1400 | entry = entry_point_address (); | |
1401 | ||
1402 | if (entry != 0) | |
1403 | return entry; | |
1404 | ||
1405 | sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile); | |
1406 | ||
1407 | if (!sym || MSYMBOL_TYPE (sym) != mst_text) | |
1408 | return 0; | |
1409 | else | |
1410 | return SYMBOL_VALUE_ADDRESS (sym) + 4; | |
ec32e4be JT |
1411 | } |
1412 | ||
1413 | /* alpha_software_single_step() is called just before we want to resume | |
1414 | the inferior, if we want to single-step it but there is no hardware | |
1415 | or kernel single-step support (NetBSD on Alpha, for example). We find | |
1416 | the target of the coming instruction and breakpoint it. | |
1417 | ||
1418 | single_step is also called just after the inferior stops. If we had | |
1419 | set up a simulated single-step, we undo our damage. */ | |
1420 | ||
1421 | static CORE_ADDR | |
1422 | alpha_next_pc (CORE_ADDR pc) | |
1423 | { | |
1424 | unsigned int insn; | |
1425 | unsigned int op; | |
1426 | int offset; | |
1427 | LONGEST rav; | |
1428 | ||
1429 | insn = read_memory_unsigned_integer (pc, sizeof (insn)); | |
1430 | ||
1431 | /* Opcode is top 6 bits. */ | |
1432 | op = (insn >> 26) & 0x3f; | |
1433 | ||
1434 | if (op == 0x1a) | |
1435 | { | |
1436 | /* Jump format: target PC is: | |
1437 | RB & ~3 */ | |
1438 | return (read_register ((insn >> 16) & 0x1f) & ~3); | |
1439 | } | |
1440 | ||
1441 | if ((op & 0x30) == 0x30) | |
1442 | { | |
1443 | /* Branch format: target PC is: | |
1444 | (new PC) + (4 * sext(displacement)) */ | |
1445 | if (op == 0x30 || /* BR */ | |
1446 | op == 0x34) /* BSR */ | |
1447 | { | |
1448 | branch_taken: | |
1449 | offset = (insn & 0x001fffff); | |
1450 | if (offset & 0x00100000) | |
1451 | offset |= 0xffe00000; | |
1452 | offset *= 4; | |
1453 | return (pc + 4 + offset); | |
1454 | } | |
1455 | ||
1456 | /* Need to determine if branch is taken; read RA. */ | |
1457 | rav = (LONGEST) read_register ((insn >> 21) & 0x1f); | |
1458 | switch (op) | |
1459 | { | |
1460 | case 0x38: /* BLBC */ | |
1461 | if ((rav & 1) == 0) | |
1462 | goto branch_taken; | |
1463 | break; | |
1464 | case 0x3c: /* BLBS */ | |
1465 | if (rav & 1) | |
1466 | goto branch_taken; | |
1467 | break; | |
1468 | case 0x39: /* BEQ */ | |
1469 | if (rav == 0) | |
1470 | goto branch_taken; | |
1471 | break; | |
1472 | case 0x3d: /* BNE */ | |
1473 | if (rav != 0) | |
1474 | goto branch_taken; | |
1475 | break; | |
1476 | case 0x3a: /* BLT */ | |
1477 | if (rav < 0) | |
1478 | goto branch_taken; | |
1479 | break; | |
1480 | case 0x3b: /* BLE */ | |
1481 | if (rav <= 0) | |
1482 | goto branch_taken; | |
1483 | break; | |
1484 | case 0x3f: /* BGT */ | |
1485 | if (rav > 0) | |
1486 | goto branch_taken; | |
1487 | break; | |
1488 | case 0x3e: /* BGE */ | |
1489 | if (rav >= 0) | |
1490 | goto branch_taken; | |
1491 | break; | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | /* Not a branch or branch not taken; target PC is: | |
1496 | pc + 4 */ | |
1497 | return (pc + 4); | |
1498 | } | |
1499 | ||
1500 | void | |
1501 | alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p) | |
1502 | { | |
1503 | static CORE_ADDR next_pc; | |
1504 | typedef char binsn_quantum[BREAKPOINT_MAX]; | |
1505 | static binsn_quantum break_mem; | |
1506 | CORE_ADDR pc; | |
1507 | ||
1508 | if (insert_breakpoints_p) | |
1509 | { | |
1510 | pc = read_pc (); | |
1511 | next_pc = alpha_next_pc (pc); | |
1512 | ||
1513 | target_insert_breakpoint (next_pc, break_mem); | |
1514 | } | |
1515 | else | |
1516 | { | |
1517 | target_remove_breakpoint (next_pc, break_mem); | |
1518 | write_pc (next_pc); | |
1519 | } | |
c906108c SS |
1520 | } |
1521 | ||
1522 | void | |
fba45db2 | 1523 | _initialize_alpha_tdep (void) |
c906108c SS |
1524 | { |
1525 | struct cmd_list_element *c; | |
1526 | ||
1527 | tm_print_insn = print_insn_alpha; | |
1528 | ||
1529 | /* Let the user set the fence post for heuristic_proc_start. */ | |
1530 | ||
1531 | /* We really would like to have both "0" and "unlimited" work, but | |
1532 | command.c doesn't deal with that. So make it a var_zinteger | |
1533 | because the user can always use "999999" or some such for unlimited. */ | |
1534 | c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger, | |
1535 | (char *) &heuristic_fence_post, | |
1536 | "\ | |
1537 | Set the distance searched for the start of a function.\n\ | |
1538 | If you are debugging a stripped executable, GDB needs to search through the\n\ | |
1539 | program for the start of a function. This command sets the distance of the\n\ | |
1540 | search. The only need to set it is when debugging a stripped executable.", | |
1541 | &setlist); | |
1542 | /* We need to throw away the frame cache when we set this, since it | |
1543 | might change our ability to get backtraces. */ | |
1544 | c->function.sfunc = reinit_frame_cache_sfunc; | |
1545 | add_show_from_set (c, &showlist); | |
1546 | } |