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 | 36 | |
140f9984 JT |
37 | struct frame_extra_info |
38 | { | |
39 | alpha_extra_func_info_t proc_desc; | |
40 | int localoff; | |
41 | int pc_reg; | |
42 | }; | |
43 | ||
c906108c SS |
44 | /* FIXME: Some of this code should perhaps be merged with mips-tdep.c. */ |
45 | ||
46 | /* Prototypes for local functions. */ | |
47 | ||
140f9984 JT |
48 | static void alpha_find_saved_regs (struct frame_info *); |
49 | ||
a14ed312 | 50 | static alpha_extra_func_info_t push_sigtramp_desc (CORE_ADDR low_addr); |
c906108c | 51 | |
a14ed312 | 52 | static CORE_ADDR read_next_frame_reg (struct frame_info *, int); |
c906108c | 53 | |
a14ed312 | 54 | static CORE_ADDR heuristic_proc_start (CORE_ADDR); |
c906108c | 55 | |
a14ed312 KB |
56 | static alpha_extra_func_info_t heuristic_proc_desc (CORE_ADDR, |
57 | CORE_ADDR, | |
58 | struct frame_info *); | |
c906108c | 59 | |
a14ed312 KB |
60 | static alpha_extra_func_info_t find_proc_desc (CORE_ADDR, |
61 | struct frame_info *); | |
c906108c SS |
62 | |
63 | #if 0 | |
a14ed312 | 64 | static int alpha_in_lenient_prologue (CORE_ADDR, CORE_ADDR); |
c906108c SS |
65 | #endif |
66 | ||
a14ed312 | 67 | static void reinit_frame_cache_sfunc (char *, int, struct cmd_list_element *); |
c906108c | 68 | |
a14ed312 KB |
69 | static CORE_ADDR after_prologue (CORE_ADDR pc, |
70 | alpha_extra_func_info_t proc_desc); | |
c906108c | 71 | |
a14ed312 KB |
72 | static int alpha_in_prologue (CORE_ADDR pc, |
73 | alpha_extra_func_info_t proc_desc); | |
c906108c | 74 | |
a14ed312 | 75 | static int alpha_about_to_return (CORE_ADDR pc); |
392a587b | 76 | |
a14ed312 | 77 | void _initialize_alpha_tdep (void); |
392a587b | 78 | |
c906108c SS |
79 | /* Heuristic_proc_start may hunt through the text section for a long |
80 | time across a 2400 baud serial line. Allows the user to limit this | |
81 | search. */ | |
82 | static unsigned int heuristic_fence_post = 0; | |
c5aa993b | 83 | /* *INDENT-OFF* */ |
c906108c SS |
84 | /* Layout of a stack frame on the alpha: |
85 | ||
86 | | | | |
87 | pdr members: | 7th ... nth arg, | | |
88 | | `pushed' by caller. | | |
89 | | | | |
90 | ----------------|-------------------------------|<-- old_sp == vfp | |
91 | ^ ^ ^ ^ | | | |
92 | | | | | | | | |
93 | | |localoff | Copies of 1st .. 6th | | |
94 | | | | | | argument if necessary. | | |
95 | | | | v | | | |
96 | | | | --- |-------------------------------|<-- FRAME_LOCALS_ADDRESS | |
97 | | | | | | | |
98 | | | | | Locals and temporaries. | | |
99 | | | | | | | |
100 | | | | |-------------------------------| | |
101 | | | | | | | |
102 | |-fregoffset | Saved float registers. | | |
103 | | | | | F9 | | |
104 | | | | | . | | |
105 | | | | | . | | |
106 | | | | | F2 | | |
107 | | | v | | | |
108 | | | -------|-------------------------------| | |
109 | | | | | | |
110 | | | | Saved registers. | | |
111 | | | | S6 | | |
112 | |-regoffset | . | | |
113 | | | | . | | |
114 | | | | S0 | | |
115 | | | | pdr.pcreg | | |
116 | | v | | | |
117 | | ----------|-------------------------------| | |
118 | | | | | |
119 | frameoffset | Argument build area, gets | | |
120 | | | 7th ... nth arg for any | | |
121 | | | called procedure. | | |
122 | v | | | |
123 | -------------|-------------------------------|<-- sp | |
124 | | | | |
125 | */ | |
c5aa993b JM |
126 | /* *INDENT-ON* */ |
127 | ||
128 | ||
c906108c | 129 | |
c5aa993b | 130 | #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ |
b83266a0 SS |
131 | /* These next two fields are kind of being hijacked. I wonder if |
132 | iline is too small for the values it needs to hold, if GDB is | |
133 | running on a 32-bit host. */ | |
c5aa993b JM |
134 | #define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */ |
135 | #define PROC_DUMMY_FRAME(proc) ((proc)->pdr.cbLineOffset) /*CALL_DUMMY frame */ | |
c906108c SS |
136 | #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) |
137 | #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) | |
138 | #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) | |
139 | #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) | |
140 | #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) | |
141 | #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) | |
142 | #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) | |
143 | #define PROC_LOCALOFF(proc) ((proc)->pdr.localoff) | |
144 | #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) | |
145 | #define _PROC_MAGIC_ 0x0F0F0F0F | |
146 | #define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_) | |
147 | #define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_) | |
148 | ||
149 | struct linked_proc_info | |
c5aa993b JM |
150 | { |
151 | struct alpha_extra_func_info info; | |
152 | struct linked_proc_info *next; | |
153 | } | |
154 | *linked_proc_desc_table = NULL; | |
c906108c | 155 | \f |
d734c450 JT |
156 | int |
157 | alpha_osf_in_sigtramp (CORE_ADDR pc, char *func_name) | |
158 | { | |
159 | return (func_name != NULL && STREQ ("__sigtramp", func_name)); | |
160 | } | |
c5aa993b | 161 | |
c906108c SS |
162 | /* Under GNU/Linux, signal handler invocations can be identified by the |
163 | designated code sequence that is used to return from a signal | |
164 | handler. In particular, the return address of a signal handler | |
165 | points to the following sequence (the first instruction is quadword | |
166 | aligned): | |
167 | ||
c5aa993b JM |
168 | bis $30,$30,$16 |
169 | addq $31,0x67,$0 | |
170 | call_pal callsys | |
c906108c SS |
171 | |
172 | Each instruction has a unique encoding, so we simply attempt to | |
173 | match the instruction the pc is pointing to with any of the above | |
174 | instructions. If there is a hit, we know the offset to the start | |
175 | of the designated sequence and can then check whether we really are | |
176 | executing in a designated sequence. If not, -1 is returned, | |
177 | otherwise the offset from the start of the desingated sequence is | |
178 | returned. | |
179 | ||
180 | There is a slight chance of false hits: code could jump into the | |
181 | middle of the designated sequence, in which case there is no | |
182 | guarantee that we are in the middle of a sigreturn syscall. Don't | |
183 | think this will be a problem in praxis, though. | |
c5aa993b | 184 | */ |
c906108c | 185 | |
7a292a7a SS |
186 | #ifndef TM_LINUXALPHA_H |
187 | /* HACK: Provide a prototype when compiling this file for non | |
188 | linuxalpha targets. */ | |
a14ed312 | 189 | long alpha_linux_sigtramp_offset (CORE_ADDR pc); |
7a292a7a | 190 | #endif |
c906108c | 191 | long |
fba45db2 | 192 | alpha_linux_sigtramp_offset (CORE_ADDR pc) |
c906108c SS |
193 | { |
194 | unsigned int i[3], w; | |
195 | long off; | |
196 | ||
c5aa993b | 197 | if (read_memory_nobpt (pc, (char *) &w, 4) != 0) |
c906108c SS |
198 | return -1; |
199 | ||
200 | off = -1; | |
201 | switch (w) | |
202 | { | |
c5aa993b JM |
203 | case 0x47de0410: |
204 | off = 0; | |
205 | break; /* bis $30,$30,$16 */ | |
206 | case 0x43ecf400: | |
207 | off = 4; | |
208 | break; /* addq $31,0x67,$0 */ | |
209 | case 0x00000083: | |
210 | off = 8; | |
211 | break; /* call_pal callsys */ | |
212 | default: | |
213 | return -1; | |
c906108c SS |
214 | } |
215 | pc -= off; | |
216 | if (pc & 0x7) | |
217 | { | |
218 | /* designated sequence is not quadword aligned */ | |
219 | return -1; | |
220 | } | |
221 | ||
c5aa993b | 222 | if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0) |
c906108c SS |
223 | return -1; |
224 | ||
225 | if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083) | |
226 | return off; | |
227 | ||
228 | return -1; | |
229 | } | |
c906108c | 230 | \f |
c5aa993b | 231 | |
c906108c SS |
232 | /* Under OSF/1, the __sigtramp routine is frameless and has a frame |
233 | size of zero, but we are able to backtrace through it. */ | |
234 | CORE_ADDR | |
fba45db2 | 235 | alpha_osf_skip_sigtramp_frame (struct frame_info *frame, CORE_ADDR pc) |
c906108c SS |
236 | { |
237 | char *name; | |
c5aa993b | 238 | find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
c906108c SS |
239 | if (IN_SIGTRAMP (pc, name)) |
240 | return frame->frame; | |
241 | else | |
242 | return 0; | |
243 | } | |
c906108c | 244 | \f |
c5aa993b | 245 | |
c906108c SS |
246 | /* Dynamically create a signal-handler caller procedure descriptor for |
247 | the signal-handler return code starting at address LOW_ADDR. The | |
248 | descriptor is added to the linked_proc_desc_table. */ | |
249 | ||
250 | static alpha_extra_func_info_t | |
fba45db2 | 251 | push_sigtramp_desc (CORE_ADDR low_addr) |
c906108c SS |
252 | { |
253 | struct linked_proc_info *link; | |
254 | alpha_extra_func_info_t proc_desc; | |
255 | ||
256 | link = (struct linked_proc_info *) | |
257 | xmalloc (sizeof (struct linked_proc_info)); | |
258 | link->next = linked_proc_desc_table; | |
259 | linked_proc_desc_table = link; | |
260 | ||
261 | proc_desc = &link->info; | |
262 | ||
263 | proc_desc->numargs = 0; | |
c5aa993b JM |
264 | PROC_LOW_ADDR (proc_desc) = low_addr; |
265 | PROC_HIGH_ADDR (proc_desc) = low_addr + 3 * 4; | |
266 | PROC_DUMMY_FRAME (proc_desc) = 0; | |
267 | PROC_FRAME_OFFSET (proc_desc) = 0x298; /* sizeof(struct sigcontext_struct) */ | |
268 | PROC_FRAME_REG (proc_desc) = SP_REGNUM; | |
269 | PROC_REG_MASK (proc_desc) = 0xffff; | |
270 | PROC_FREG_MASK (proc_desc) = 0xffff; | |
271 | PROC_PC_REG (proc_desc) = 26; | |
272 | PROC_LOCALOFF (proc_desc) = 0; | |
c906108c SS |
273 | SET_PROC_DESC_IS_DYN_SIGTRAMP (proc_desc); |
274 | return (proc_desc); | |
275 | } | |
c906108c | 276 | \f |
c5aa993b | 277 | |
636a6dfc JT |
278 | char * |
279 | alpha_register_name (int regno) | |
280 | { | |
281 | static char *register_names[] = | |
282 | { | |
283 | "v0", "t0", "t1", "t2", "t3", "t4", "t5", "t6", | |
284 | "t7", "s0", "s1", "s2", "s3", "s4", "s5", "fp", | |
285 | "a0", "a1", "a2", "a3", "a4", "a5", "t8", "t9", | |
286 | "t10", "t11", "ra", "t12", "at", "gp", "sp", "zero", | |
287 | "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", | |
288 | "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", | |
289 | "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", | |
290 | "f24", "f25", "f26", "f27", "f28", "f29", "f30", "fpcr", | |
291 | "pc", "vfp", | |
292 | }; | |
293 | ||
294 | if (regno < 0) | |
295 | return (NULL); | |
296 | if (regno >= (sizeof(register_names) / sizeof(*register_names))) | |
297 | return (NULL); | |
298 | return (register_names[regno]); | |
299 | } | |
d734c450 JT |
300 | |
301 | int | |
302 | alpha_cannot_fetch_register (int regno) | |
303 | { | |
304 | return (regno == FP_REGNUM || regno == ZERO_REGNUM); | |
305 | } | |
306 | ||
307 | int | |
308 | alpha_cannot_store_register (int regno) | |
309 | { | |
310 | return (regno == FP_REGNUM || regno == ZERO_REGNUM); | |
311 | } | |
312 | ||
313 | int | |
314 | alpha_register_convertible (int regno) | |
315 | { | |
316 | return (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31); | |
317 | } | |
0d056799 JT |
318 | |
319 | struct type * | |
320 | alpha_register_virtual_type (int regno) | |
321 | { | |
322 | return ((regno >= FP0_REGNUM && regno < (FP0_REGNUM+31)) | |
323 | ? builtin_type_double : builtin_type_long); | |
324 | } | |
f8453e34 JT |
325 | |
326 | int | |
327 | alpha_register_byte (int regno) | |
328 | { | |
329 | return (regno * 8); | |
330 | } | |
331 | ||
332 | int | |
333 | alpha_register_raw_size (int regno) | |
334 | { | |
335 | return 8; | |
336 | } | |
337 | ||
338 | int | |
339 | alpha_register_virtual_size (int regno) | |
340 | { | |
341 | return 8; | |
342 | } | |
636a6dfc JT |
343 | \f |
344 | ||
c906108c SS |
345 | /* Guaranteed to set frame->saved_regs to some values (it never leaves it |
346 | NULL). */ | |
347 | ||
140f9984 | 348 | static void |
fba45db2 | 349 | alpha_find_saved_regs (struct frame_info *frame) |
c906108c SS |
350 | { |
351 | int ireg; | |
352 | CORE_ADDR reg_position; | |
353 | unsigned long mask; | |
354 | alpha_extra_func_info_t proc_desc; | |
355 | int returnreg; | |
356 | ||
357 | frame_saved_regs_zalloc (frame); | |
358 | ||
359 | /* If it is the frame for __sigtramp, the saved registers are located | |
360 | in a sigcontext structure somewhere on the stack. __sigtramp | |
361 | passes a pointer to the sigcontext structure on the stack. | |
362 | If the stack layout for __sigtramp changes, or if sigcontext offsets | |
363 | change, we might have to update this code. */ | |
364 | #ifndef SIGFRAME_PC_OFF | |
365 | #define SIGFRAME_PC_OFF (2 * 8) | |
366 | #define SIGFRAME_REGSAVE_OFF (4 * 8) | |
367 | #define SIGFRAME_FPREGSAVE_OFF (SIGFRAME_REGSAVE_OFF + 32 * 8 + 8) | |
368 | #endif | |
369 | if (frame->signal_handler_caller) | |
370 | { | |
371 | CORE_ADDR sigcontext_addr; | |
372 | ||
373 | sigcontext_addr = SIGCONTEXT_ADDR (frame); | |
374 | for (ireg = 0; ireg < 32; ireg++) | |
375 | { | |
c5aa993b JM |
376 | reg_position = sigcontext_addr + SIGFRAME_REGSAVE_OFF + ireg * 8; |
377 | frame->saved_regs[ireg] = reg_position; | |
c906108c SS |
378 | } |
379 | for (ireg = 0; ireg < 32; ireg++) | |
380 | { | |
c5aa993b JM |
381 | reg_position = sigcontext_addr + SIGFRAME_FPREGSAVE_OFF + ireg * 8; |
382 | frame->saved_regs[FP0_REGNUM + ireg] = reg_position; | |
c906108c SS |
383 | } |
384 | frame->saved_regs[PC_REGNUM] = sigcontext_addr + SIGFRAME_PC_OFF; | |
385 | return; | |
386 | } | |
387 | ||
140f9984 | 388 | proc_desc = frame->extra_info->proc_desc; |
c906108c SS |
389 | if (proc_desc == NULL) |
390 | /* I'm not sure how/whether this can happen. Normally when we can't | |
391 | find a proc_desc, we "synthesize" one using heuristic_proc_desc | |
392 | and set the saved_regs right away. */ | |
393 | return; | |
394 | ||
395 | /* Fill in the offsets for the registers which gen_mask says | |
396 | were saved. */ | |
397 | ||
398 | reg_position = frame->frame + PROC_REG_OFFSET (proc_desc); | |
399 | mask = PROC_REG_MASK (proc_desc); | |
400 | ||
401 | returnreg = PROC_PC_REG (proc_desc); | |
402 | ||
403 | /* Note that RA is always saved first, regardless of its actual | |
404 | register number. */ | |
405 | if (mask & (1 << returnreg)) | |
406 | { | |
407 | frame->saved_regs[returnreg] = reg_position; | |
408 | reg_position += 8; | |
c5aa993b JM |
409 | mask &= ~(1 << returnreg); /* Clear bit for RA so we |
410 | don't save again later. */ | |
c906108c SS |
411 | } |
412 | ||
c5aa993b | 413 | for (ireg = 0; ireg <= 31; ++ireg) |
c906108c SS |
414 | if (mask & (1 << ireg)) |
415 | { | |
416 | frame->saved_regs[ireg] = reg_position; | |
417 | reg_position += 8; | |
418 | } | |
419 | ||
420 | /* Fill in the offsets for the registers which float_mask says | |
421 | were saved. */ | |
422 | ||
423 | reg_position = frame->frame + PROC_FREG_OFFSET (proc_desc); | |
424 | mask = PROC_FREG_MASK (proc_desc); | |
425 | ||
c5aa993b | 426 | for (ireg = 0; ireg <= 31; ++ireg) |
c906108c SS |
427 | if (mask & (1 << ireg)) |
428 | { | |
c5aa993b | 429 | frame->saved_regs[FP0_REGNUM + ireg] = reg_position; |
c906108c SS |
430 | reg_position += 8; |
431 | } | |
432 | ||
433 | frame->saved_regs[PC_REGNUM] = frame->saved_regs[returnreg]; | |
434 | } | |
435 | ||
140f9984 JT |
436 | void |
437 | alpha_frame_init_saved_regs (struct frame_info *fi) | |
438 | { | |
439 | if (fi->saved_regs == NULL) | |
440 | alpha_find_saved_regs (fi); | |
441 | fi->saved_regs[SP_REGNUM] = fi->frame; | |
442 | } | |
443 | ||
0d056799 JT |
444 | void |
445 | alpha_init_frame_pc_first (int fromleaf, struct frame_info *prev) | |
446 | { | |
447 | prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : | |
448 | prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ()); | |
449 | } | |
450 | ||
c906108c | 451 | static CORE_ADDR |
fba45db2 | 452 | read_next_frame_reg (struct frame_info *fi, int regno) |
c906108c SS |
453 | { |
454 | for (; fi; fi = fi->next) | |
455 | { | |
456 | /* We have to get the saved sp from the sigcontext | |
c5aa993b | 457 | if it is a signal handler frame. */ |
c906108c SS |
458 | if (regno == SP_REGNUM && !fi->signal_handler_caller) |
459 | return fi->frame; | |
460 | else | |
461 | { | |
462 | if (fi->saved_regs == NULL) | |
463 | alpha_find_saved_regs (fi); | |
464 | if (fi->saved_regs[regno]) | |
c5aa993b | 465 | return read_memory_integer (fi->saved_regs[regno], 8); |
c906108c SS |
466 | } |
467 | } | |
c5aa993b | 468 | return read_register (regno); |
c906108c SS |
469 | } |
470 | ||
471 | CORE_ADDR | |
fba45db2 | 472 | alpha_frame_saved_pc (struct frame_info *frame) |
c906108c | 473 | { |
140f9984 | 474 | alpha_extra_func_info_t proc_desc = frame->extra_info->proc_desc; |
c906108c SS |
475 | /* We have to get the saved pc from the sigcontext |
476 | if it is a signal handler frame. */ | |
140f9984 JT |
477 | int pcreg = frame->signal_handler_caller ? PC_REGNUM |
478 | : frame->extra_info->pc_reg; | |
c906108c | 479 | |
c5aa993b JM |
480 | if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc)) |
481 | return read_memory_integer (frame->frame - 8, 8); | |
c906108c | 482 | |
c5aa993b | 483 | return read_next_frame_reg (frame, pcreg); |
c906108c SS |
484 | } |
485 | ||
486 | CORE_ADDR | |
fba45db2 | 487 | alpha_saved_pc_after_call (struct frame_info *frame) |
c906108c SS |
488 | { |
489 | CORE_ADDR pc = frame->pc; | |
490 | CORE_ADDR tmp; | |
491 | alpha_extra_func_info_t proc_desc; | |
492 | int pcreg; | |
493 | ||
494 | /* Skip over shared library trampoline if necessary. */ | |
495 | tmp = SKIP_TRAMPOLINE_CODE (pc); | |
496 | if (tmp != 0) | |
497 | pc = tmp; | |
498 | ||
499 | proc_desc = find_proc_desc (pc, frame->next); | |
500 | pcreg = proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM; | |
501 | ||
502 | if (frame->signal_handler_caller) | |
503 | return alpha_frame_saved_pc (frame); | |
504 | else | |
505 | return read_register (pcreg); | |
506 | } | |
507 | ||
508 | ||
509 | static struct alpha_extra_func_info temp_proc_desc; | |
140f9984 | 510 | static CORE_ADDR temp_saved_regs[NUM_REGS]; |
c906108c SS |
511 | |
512 | /* Nonzero if instruction at PC is a return instruction. "ret | |
513 | $zero,($ra),1" on alpha. */ | |
514 | ||
515 | static int | |
fba45db2 | 516 | alpha_about_to_return (CORE_ADDR pc) |
c906108c SS |
517 | { |
518 | return read_memory_integer (pc, 4) == 0x6bfa8001; | |
519 | } | |
520 | ||
521 | ||
522 | ||
523 | /* This fencepost looks highly suspicious to me. Removing it also | |
524 | seems suspicious as it could affect remote debugging across serial | |
525 | lines. */ | |
526 | ||
527 | static CORE_ADDR | |
fba45db2 | 528 | heuristic_proc_start (CORE_ADDR pc) |
c906108c | 529 | { |
c5aa993b JM |
530 | CORE_ADDR start_pc = pc; |
531 | CORE_ADDR fence = start_pc - heuristic_fence_post; | |
c906108c | 532 | |
c5aa993b JM |
533 | if (start_pc == 0) |
534 | return 0; | |
c906108c | 535 | |
c5aa993b JM |
536 | if (heuristic_fence_post == UINT_MAX |
537 | || fence < VM_MIN_ADDRESS) | |
538 | fence = VM_MIN_ADDRESS; | |
c906108c | 539 | |
c5aa993b JM |
540 | /* search back for previous return */ |
541 | for (start_pc -= 4;; start_pc -= 4) | |
542 | if (start_pc < fence) | |
543 | { | |
544 | /* It's not clear to me why we reach this point when | |
545 | stop_soon_quietly, but with this test, at least we | |
546 | don't print out warnings for every child forked (eg, on | |
547 | decstation). 22apr93 rich@cygnus.com. */ | |
548 | if (!stop_soon_quietly) | |
c906108c | 549 | { |
c5aa993b JM |
550 | static int blurb_printed = 0; |
551 | ||
552 | if (fence == VM_MIN_ADDRESS) | |
553 | warning ("Hit beginning of text section without finding"); | |
554 | else | |
555 | warning ("Hit heuristic-fence-post without finding"); | |
556 | ||
d4f3574e | 557 | warning ("enclosing function for address 0x%s", paddr_nz (pc)); |
c5aa993b | 558 | if (!blurb_printed) |
c906108c | 559 | { |
c5aa993b | 560 | printf_filtered ("\ |
c906108c SS |
561 | This warning occurs if you are debugging a function without any symbols\n\ |
562 | (for example, in a stripped executable). In that case, you may wish to\n\ | |
563 | increase the size of the search with the `set heuristic-fence-post' command.\n\ | |
564 | \n\ | |
565 | Otherwise, you told GDB there was a function where there isn't one, or\n\ | |
566 | (more likely) you have encountered a bug in GDB.\n"); | |
c5aa993b | 567 | blurb_printed = 1; |
c906108c | 568 | } |
c906108c | 569 | } |
c906108c | 570 | |
c5aa993b JM |
571 | return 0; |
572 | } | |
573 | else if (alpha_about_to_return (start_pc)) | |
574 | break; | |
575 | ||
576 | start_pc += 4; /* skip return */ | |
577 | return start_pc; | |
c906108c SS |
578 | } |
579 | ||
580 | static alpha_extra_func_info_t | |
fba45db2 KB |
581 | heuristic_proc_desc (CORE_ADDR start_pc, CORE_ADDR limit_pc, |
582 | struct frame_info *next_frame) | |
c906108c | 583 | { |
c5aa993b JM |
584 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); |
585 | CORE_ADDR cur_pc; | |
586 | int frame_size; | |
587 | int has_frame_reg = 0; | |
588 | unsigned long reg_mask = 0; | |
589 | int pcreg = -1; | |
590 | ||
591 | if (start_pc == 0) | |
592 | return NULL; | |
593 | memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc)); | |
140f9984 | 594 | memset (&temp_saved_regs, '\0', SIZEOF_FRAME_SAVED_REGS); |
c5aa993b JM |
595 | PROC_LOW_ADDR (&temp_proc_desc) = start_pc; |
596 | ||
597 | if (start_pc + 200 < limit_pc) | |
598 | limit_pc = start_pc + 200; | |
599 | frame_size = 0; | |
600 | for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += 4) | |
601 | { | |
602 | char buf[4]; | |
603 | unsigned long word; | |
604 | int status; | |
c906108c | 605 | |
c5aa993b JM |
606 | status = read_memory_nobpt (cur_pc, buf, 4); |
607 | if (status) | |
608 | memory_error (status, cur_pc); | |
609 | word = extract_unsigned_integer (buf, 4); | |
c906108c | 610 | |
c5aa993b JM |
611 | if ((word & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ |
612 | { | |
613 | if (word & 0x8000) | |
614 | frame_size += (-word) & 0xffff; | |
615 | else | |
616 | /* Exit loop if a positive stack adjustment is found, which | |
617 | usually means that the stack cleanup code in the function | |
618 | epilogue is reached. */ | |
619 | break; | |
620 | } | |
621 | else if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ | |
622 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
623 | { | |
624 | int reg = (word & 0x03e00000) >> 21; | |
625 | reg_mask |= 1 << reg; | |
140f9984 | 626 | temp_saved_regs[reg] = sp + (short) word; |
c5aa993b JM |
627 | |
628 | /* Starting with OSF/1-3.2C, the system libraries are shipped | |
629 | without local symbols, but they still contain procedure | |
630 | descriptors without a symbol reference. GDB is currently | |
631 | unable to find these procedure descriptors and uses | |
632 | heuristic_proc_desc instead. | |
633 | As some low level compiler support routines (__div*, __add*) | |
634 | use a non-standard return address register, we have to | |
635 | add some heuristics to determine the return address register, | |
636 | or stepping over these routines will fail. | |
637 | Usually the return address register is the first register | |
638 | saved on the stack, but assembler optimization might | |
639 | rearrange the register saves. | |
640 | So we recognize only a few registers (t7, t9, ra) within | |
641 | the procedure prologue as valid return address registers. | |
642 | If we encounter a return instruction, we extract the | |
643 | the return address register from it. | |
644 | ||
645 | FIXME: Rewriting GDB to access the procedure descriptors, | |
646 | e.g. via the minimal symbol table, might obviate this hack. */ | |
647 | if (pcreg == -1 | |
648 | && cur_pc < (start_pc + 80) | |
649 | && (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM)) | |
650 | pcreg = reg; | |
651 | } | |
652 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
653 | pcreg = (word >> 16) & 0x1f; | |
654 | else if (word == 0x47de040f) /* bis sp,sp fp */ | |
655 | has_frame_reg = 1; | |
656 | } | |
657 | if (pcreg == -1) | |
658 | { | |
659 | /* If we haven't found a valid return address register yet, | |
660 | keep searching in the procedure prologue. */ | |
661 | while (cur_pc < (limit_pc + 80) && cur_pc < (start_pc + 80)) | |
662 | { | |
663 | char buf[4]; | |
664 | unsigned long word; | |
c906108c | 665 | |
c5aa993b JM |
666 | if (read_memory_nobpt (cur_pc, buf, 4)) |
667 | break; | |
668 | cur_pc += 4; | |
669 | word = extract_unsigned_integer (buf, 4); | |
c906108c | 670 | |
c5aa993b JM |
671 | if ((word & 0xfc1f0000) == 0xb41e0000 /* stq reg,n($sp) */ |
672 | && (word & 0xffff0000) != 0xb7fe0000) /* reg != $zero */ | |
673 | { | |
674 | int reg = (word & 0x03e00000) >> 21; | |
675 | if (reg == T7_REGNUM || reg == T9_REGNUM || reg == RA_REGNUM) | |
676 | { | |
677 | pcreg = reg; | |
678 | break; | |
679 | } | |
680 | } | |
681 | else if ((word & 0xffe0ffff) == 0x6be08001) /* ret zero,reg,1 */ | |
682 | { | |
683 | pcreg = (word >> 16) & 0x1f; | |
684 | break; | |
685 | } | |
686 | } | |
687 | } | |
c906108c | 688 | |
c5aa993b JM |
689 | if (has_frame_reg) |
690 | PROC_FRAME_REG (&temp_proc_desc) = GCC_FP_REGNUM; | |
691 | else | |
692 | PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM; | |
693 | PROC_FRAME_OFFSET (&temp_proc_desc) = frame_size; | |
694 | PROC_REG_MASK (&temp_proc_desc) = reg_mask; | |
695 | PROC_PC_REG (&temp_proc_desc) = (pcreg == -1) ? RA_REGNUM : pcreg; | |
696 | PROC_LOCALOFF (&temp_proc_desc) = 0; /* XXX - bogus */ | |
697 | return &temp_proc_desc; | |
c906108c SS |
698 | } |
699 | ||
700 | /* This returns the PC of the first inst after the prologue. If we can't | |
701 | find the prologue, then return 0. */ | |
702 | ||
703 | static CORE_ADDR | |
fba45db2 | 704 | after_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) |
c906108c SS |
705 | { |
706 | struct symtab_and_line sal; | |
707 | CORE_ADDR func_addr, func_end; | |
708 | ||
709 | if (!proc_desc) | |
710 | proc_desc = find_proc_desc (pc, NULL); | |
711 | ||
712 | if (proc_desc) | |
713 | { | |
714 | if (PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)) | |
715 | return PROC_LOW_ADDR (proc_desc); /* "prologue" is in kernel */ | |
716 | ||
717 | /* If function is frameless, then we need to do it the hard way. I | |
c5aa993b | 718 | strongly suspect that frameless always means prologueless... */ |
c906108c SS |
719 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM |
720 | && PROC_FRAME_OFFSET (proc_desc) == 0) | |
721 | return 0; | |
722 | } | |
723 | ||
724 | if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
725 | return 0; /* Unknown */ | |
726 | ||
727 | sal = find_pc_line (func_addr, 0); | |
728 | ||
729 | if (sal.end < func_end) | |
730 | return sal.end; | |
731 | ||
732 | /* The line after the prologue is after the end of the function. In this | |
733 | case, tell the caller to find the prologue the hard way. */ | |
734 | ||
735 | return 0; | |
736 | } | |
737 | ||
738 | /* Return non-zero if we *might* be in a function prologue. Return zero if we | |
739 | are definitively *not* in a function prologue. */ | |
740 | ||
741 | static int | |
fba45db2 | 742 | alpha_in_prologue (CORE_ADDR pc, alpha_extra_func_info_t proc_desc) |
c906108c SS |
743 | { |
744 | CORE_ADDR after_prologue_pc; | |
745 | ||
746 | after_prologue_pc = after_prologue (pc, proc_desc); | |
747 | ||
748 | if (after_prologue_pc == 0 | |
749 | || pc < after_prologue_pc) | |
750 | return 1; | |
751 | else | |
752 | return 0; | |
753 | } | |
754 | ||
755 | static alpha_extra_func_info_t | |
fba45db2 | 756 | find_proc_desc (CORE_ADDR pc, struct frame_info *next_frame) |
c906108c SS |
757 | { |
758 | alpha_extra_func_info_t proc_desc; | |
759 | struct block *b; | |
760 | struct symbol *sym; | |
761 | CORE_ADDR startaddr; | |
762 | ||
763 | /* Try to get the proc_desc from the linked call dummy proc_descs | |
764 | if the pc is in the call dummy. | |
765 | This is hairy. In the case of nested dummy calls we have to find the | |
766 | right proc_desc, but we might not yet know the frame for the dummy | |
767 | as it will be contained in the proc_desc we are searching for. | |
768 | So we have to find the proc_desc whose frame is closest to the current | |
769 | stack pointer. */ | |
770 | ||
771 | if (PC_IN_CALL_DUMMY (pc, 0, 0)) | |
772 | { | |
773 | struct linked_proc_info *link; | |
774 | CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM); | |
775 | alpha_extra_func_info_t found_proc_desc = NULL; | |
776 | long min_distance = LONG_MAX; | |
777 | ||
778 | for (link = linked_proc_desc_table; link; link = link->next) | |
779 | { | |
780 | long distance = (CORE_ADDR) PROC_DUMMY_FRAME (&link->info) - sp; | |
781 | if (distance > 0 && distance < min_distance) | |
782 | { | |
783 | min_distance = distance; | |
784 | found_proc_desc = &link->info; | |
785 | } | |
786 | } | |
787 | if (found_proc_desc != NULL) | |
788 | return found_proc_desc; | |
789 | } | |
790 | ||
c5aa993b | 791 | b = block_for_pc (pc); |
c906108c SS |
792 | |
793 | find_pc_partial_function (pc, NULL, &startaddr, NULL); | |
794 | if (b == NULL) | |
795 | sym = NULL; | |
796 | else | |
797 | { | |
798 | if (startaddr > BLOCK_START (b)) | |
799 | /* This is the "pathological" case referred to in a comment in | |
800 | print_frame_info. It might be better to move this check into | |
801 | symbol reading. */ | |
802 | sym = NULL; | |
803 | else | |
804 | sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, | |
805 | 0, NULL); | |
806 | } | |
807 | ||
808 | /* If we never found a PDR for this function in symbol reading, then | |
809 | examine prologues to find the information. */ | |
810 | if (sym && ((mips_extra_func_info_t) SYMBOL_VALUE (sym))->pdr.framereg == -1) | |
811 | sym = NULL; | |
812 | ||
813 | if (sym) | |
814 | { | |
c5aa993b JM |
815 | /* IF this is the topmost frame AND |
816 | * (this proc does not have debugging information OR | |
817 | * the PC is in the procedure prologue) | |
818 | * THEN create a "heuristic" proc_desc (by analyzing | |
819 | * the actual code) to replace the "official" proc_desc. | |
820 | */ | |
821 | proc_desc = (alpha_extra_func_info_t) SYMBOL_VALUE (sym); | |
822 | if (next_frame == NULL) | |
823 | { | |
824 | if (PROC_DESC_IS_DUMMY (proc_desc) || alpha_in_prologue (pc, proc_desc)) | |
825 | { | |
826 | alpha_extra_func_info_t found_heuristic = | |
827 | heuristic_proc_desc (PROC_LOW_ADDR (proc_desc), | |
828 | pc, next_frame); | |
829 | if (found_heuristic) | |
830 | { | |
831 | PROC_LOCALOFF (found_heuristic) = | |
832 | PROC_LOCALOFF (proc_desc); | |
833 | PROC_PC_REG (found_heuristic) = PROC_PC_REG (proc_desc); | |
834 | proc_desc = found_heuristic; | |
835 | } | |
836 | } | |
837 | } | |
c906108c SS |
838 | } |
839 | else | |
840 | { | |
841 | long offset; | |
842 | ||
843 | /* Is linked_proc_desc_table really necessary? It only seems to be used | |
c5aa993b JM |
844 | by procedure call dummys. However, the procedures being called ought |
845 | to have their own proc_descs, and even if they don't, | |
846 | heuristic_proc_desc knows how to create them! */ | |
c906108c SS |
847 | |
848 | register struct linked_proc_info *link; | |
849 | for (link = linked_proc_desc_table; link; link = link->next) | |
c5aa993b JM |
850 | if (PROC_LOW_ADDR (&link->info) <= pc |
851 | && PROC_HIGH_ADDR (&link->info) > pc) | |
852 | return &link->info; | |
c906108c SS |
853 | |
854 | /* If PC is inside a dynamically generated sigtramp handler, | |
c5aa993b | 855 | create and push a procedure descriptor for that code: */ |
c906108c SS |
856 | offset = DYNAMIC_SIGTRAMP_OFFSET (pc); |
857 | if (offset >= 0) | |
858 | return push_sigtramp_desc (pc - offset); | |
859 | ||
860 | /* If heuristic_fence_post is non-zero, determine the procedure | |
c5aa993b JM |
861 | start address by examining the instructions. |
862 | This allows us to find the start address of static functions which | |
863 | have no symbolic information, as startaddr would have been set to | |
864 | the preceding global function start address by the | |
865 | find_pc_partial_function call above. */ | |
c906108c SS |
866 | if (startaddr == 0 || heuristic_fence_post != 0) |
867 | startaddr = heuristic_proc_start (pc); | |
868 | ||
869 | proc_desc = | |
870 | heuristic_proc_desc (startaddr, pc, next_frame); | |
871 | } | |
872 | return proc_desc; | |
873 | } | |
874 | ||
875 | alpha_extra_func_info_t cached_proc_desc; | |
876 | ||
877 | CORE_ADDR | |
fba45db2 | 878 | alpha_frame_chain (struct frame_info *frame) |
c906108c | 879 | { |
c5aa993b JM |
880 | alpha_extra_func_info_t proc_desc; |
881 | CORE_ADDR saved_pc = FRAME_SAVED_PC (frame); | |
882 | ||
883 | if (saved_pc == 0 || inside_entry_file (saved_pc)) | |
884 | return 0; | |
885 | ||
886 | proc_desc = find_proc_desc (saved_pc, frame); | |
887 | if (!proc_desc) | |
888 | return 0; | |
889 | ||
890 | cached_proc_desc = proc_desc; | |
891 | ||
892 | /* Fetch the frame pointer for a dummy frame from the procedure | |
893 | descriptor. */ | |
894 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
895 | return (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc); | |
896 | ||
897 | /* If no frame pointer and frame size is zero, we must be at end | |
898 | of stack (or otherwise hosed). If we don't check frame size, | |
899 | we loop forever if we see a zero size frame. */ | |
900 | if (PROC_FRAME_REG (proc_desc) == SP_REGNUM | |
901 | && PROC_FRAME_OFFSET (proc_desc) == 0 | |
902 | /* The previous frame from a sigtramp frame might be frameless | |
903 | and have frame size zero. */ | |
904 | && !frame->signal_handler_caller) | |
905 | return FRAME_PAST_SIGTRAMP_FRAME (frame, saved_pc); | |
906 | else | |
907 | return read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc)) | |
908 | + PROC_FRAME_OFFSET (proc_desc); | |
c906108c SS |
909 | } |
910 | ||
911 | void | |
140f9984 JT |
912 | alpha_print_extra_frame_info (struct frame_info *fi) |
913 | { | |
914 | if (fi | |
915 | && fi->extra_info | |
916 | && fi->extra_info->proc_desc | |
917 | && fi->extra_info->proc_desc->pdr.framereg < NUM_REGS) | |
918 | printf_filtered (" frame pointer is at %s+%s\n", | |
919 | REGISTER_NAME (fi->extra_info->proc_desc->pdr.framereg), | |
920 | paddr_d (fi->extra_info->proc_desc->pdr.frameoffset)); | |
921 | } | |
922 | ||
923 | void | |
924 | alpha_init_extra_frame_info (int fromleaf, struct frame_info *frame) | |
c906108c SS |
925 | { |
926 | /* Use proc_desc calculated in frame_chain */ | |
927 | alpha_extra_func_info_t proc_desc = | |
c5aa993b | 928 | frame->next ? cached_proc_desc : find_proc_desc (frame->pc, frame->next); |
c906108c | 929 | |
140f9984 JT |
930 | frame->extra_info = (struct frame_extra_info *) |
931 | frame_obstack_alloc (sizeof (struct frame_extra_info)); | |
932 | ||
c906108c | 933 | frame->saved_regs = NULL; |
140f9984 JT |
934 | frame->extra_info->localoff = 0; |
935 | frame->extra_info->pc_reg = RA_REGNUM; | |
936 | frame->extra_info->proc_desc = proc_desc == &temp_proc_desc ? 0 : proc_desc; | |
c906108c SS |
937 | if (proc_desc) |
938 | { | |
939 | /* Get the locals offset and the saved pc register from the | |
c5aa993b JM |
940 | procedure descriptor, they are valid even if we are in the |
941 | middle of the prologue. */ | |
140f9984 JT |
942 | frame->extra_info->localoff = PROC_LOCALOFF (proc_desc); |
943 | frame->extra_info->pc_reg = PROC_PC_REG (proc_desc); | |
c906108c SS |
944 | |
945 | /* Fixup frame-pointer - only needed for top frame */ | |
946 | ||
947 | /* Fetch the frame pointer for a dummy frame from the procedure | |
c5aa993b JM |
948 | descriptor. */ |
949 | if (PROC_DESC_IS_DUMMY (proc_desc)) | |
950 | frame->frame = (CORE_ADDR) PROC_DUMMY_FRAME (proc_desc); | |
c906108c SS |
951 | |
952 | /* This may not be quite right, if proc has a real frame register. | |
c5aa993b JM |
953 | Get the value of the frame relative sp, procedure might have been |
954 | interrupted by a signal at it's very start. */ | |
c906108c SS |
955 | else if (frame->pc == PROC_LOW_ADDR (proc_desc) |
956 | && !PROC_DESC_IS_DYN_SIGTRAMP (proc_desc)) | |
957 | frame->frame = read_next_frame_reg (frame->next, SP_REGNUM); | |
958 | else | |
959 | frame->frame = read_next_frame_reg (frame->next, PROC_FRAME_REG (proc_desc)) | |
960 | + PROC_FRAME_OFFSET (proc_desc); | |
961 | ||
962 | if (proc_desc == &temp_proc_desc) | |
963 | { | |
964 | char *name; | |
965 | ||
966 | /* Do not set the saved registers for a sigtramp frame, | |
967 | alpha_find_saved_registers will do that for us. | |
968 | We can't use frame->signal_handler_caller, it is not yet set. */ | |
969 | find_pc_partial_function (frame->pc, &name, | |
c5aa993b | 970 | (CORE_ADDR *) NULL, (CORE_ADDR *) NULL); |
c906108c SS |
971 | if (!IN_SIGTRAMP (frame->pc, name)) |
972 | { | |
c5aa993b | 973 | frame->saved_regs = (CORE_ADDR *) |
c906108c | 974 | frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS); |
140f9984 JT |
975 | memcpy (frame->saved_regs, temp_saved_regs, |
976 | SIZEOF_FRAME_SAVED_REGS); | |
c906108c SS |
977 | frame->saved_regs[PC_REGNUM] |
978 | = frame->saved_regs[RA_REGNUM]; | |
979 | } | |
980 | } | |
981 | } | |
982 | } | |
983 | ||
140f9984 JT |
984 | CORE_ADDR |
985 | alpha_frame_locals_address (struct frame_info *fi) | |
986 | { | |
987 | return (fi->frame - fi->extra_info->localoff); | |
988 | } | |
989 | ||
990 | CORE_ADDR | |
991 | alpha_frame_args_address (struct frame_info *fi) | |
992 | { | |
993 | return (fi->frame - (ALPHA_NUM_ARG_REGS * 8)); | |
994 | } | |
995 | ||
c906108c SS |
996 | /* ALPHA stack frames are almost impenetrable. When execution stops, |
997 | we basically have to look at symbol information for the function | |
998 | that we stopped in, which tells us *which* register (if any) is | |
999 | the base of the frame pointer, and what offset from that register | |
1000 | the frame itself is at. | |
1001 | ||
1002 | This presents a problem when trying to examine a stack in memory | |
1003 | (that isn't executing at the moment), using the "frame" command. We | |
1004 | don't have a PC, nor do we have any registers except SP. | |
1005 | ||
1006 | This routine takes two arguments, SP and PC, and tries to make the | |
1007 | cached frames look as if these two arguments defined a frame on the | |
1008 | cache. This allows the rest of info frame to extract the important | |
1009 | arguments without difficulty. */ | |
1010 | ||
1011 | struct frame_info * | |
fba45db2 | 1012 | setup_arbitrary_frame (int argc, CORE_ADDR *argv) |
c906108c SS |
1013 | { |
1014 | if (argc != 2) | |
1015 | error ("ALPHA frame specifications require two arguments: sp and pc"); | |
1016 | ||
1017 | return create_new_frame (argv[0], argv[1]); | |
1018 | } | |
1019 | ||
1020 | /* The alpha passes the first six arguments in the registers, the rest on | |
1021 | the stack. The register arguments are eventually transferred to the | |
1022 | argument transfer area immediately below the stack by the called function | |
1023 | anyway. So we `push' at least six arguments on the stack, `reload' the | |
1024 | argument registers and then adjust the stack pointer to point past the | |
1025 | sixth argument. This algorithm simplifies the passing of a large struct | |
1026 | which extends from the registers to the stack. | |
1027 | If the called function is returning a structure, the address of the | |
1028 | structure to be returned is passed as a hidden first argument. */ | |
1029 | ||
1030 | CORE_ADDR | |
ea7c478f | 1031 | alpha_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
fba45db2 | 1032 | int struct_return, CORE_ADDR struct_addr) |
c906108c | 1033 | { |
7a292a7a | 1034 | int i; |
c906108c SS |
1035 | int accumulate_size = struct_return ? 8 : 0; |
1036 | int arg_regs_size = ALPHA_NUM_ARG_REGS * 8; | |
c5aa993b JM |
1037 | struct alpha_arg |
1038 | { | |
1039 | char *contents; | |
1040 | int len; | |
1041 | int offset; | |
1042 | }; | |
c906108c | 1043 | struct alpha_arg *alpha_args = |
c5aa993b | 1044 | (struct alpha_arg *) alloca (nargs * sizeof (struct alpha_arg)); |
c906108c SS |
1045 | register struct alpha_arg *m_arg; |
1046 | char raw_buffer[sizeof (CORE_ADDR)]; | |
1047 | int required_arg_regs; | |
1048 | ||
1049 | for (i = 0, m_arg = alpha_args; i < nargs; i++, m_arg++) | |
1050 | { | |
ea7c478f | 1051 | struct value *arg = args[i]; |
c906108c SS |
1052 | struct type *arg_type = check_typedef (VALUE_TYPE (arg)); |
1053 | /* Cast argument to long if necessary as the compiler does it too. */ | |
1054 | switch (TYPE_CODE (arg_type)) | |
1055 | { | |
1056 | case TYPE_CODE_INT: | |
1057 | case TYPE_CODE_BOOL: | |
1058 | case TYPE_CODE_CHAR: | |
1059 | case TYPE_CODE_RANGE: | |
1060 | case TYPE_CODE_ENUM: | |
1061 | if (TYPE_LENGTH (arg_type) < TYPE_LENGTH (builtin_type_long)) | |
1062 | { | |
1063 | arg_type = builtin_type_long; | |
1064 | arg = value_cast (arg_type, arg); | |
1065 | } | |
1066 | break; | |
1067 | default: | |
1068 | break; | |
1069 | } | |
1070 | m_arg->len = TYPE_LENGTH (arg_type); | |
1071 | m_arg->offset = accumulate_size; | |
1072 | accumulate_size = (accumulate_size + m_arg->len + 7) & ~7; | |
c5aa993b | 1073 | m_arg->contents = VALUE_CONTENTS (arg); |
c906108c SS |
1074 | } |
1075 | ||
1076 | /* Determine required argument register loads, loading an argument register | |
1077 | is expensive as it uses three ptrace calls. */ | |
1078 | required_arg_regs = accumulate_size / 8; | |
1079 | if (required_arg_regs > ALPHA_NUM_ARG_REGS) | |
1080 | required_arg_regs = ALPHA_NUM_ARG_REGS; | |
1081 | ||
1082 | /* Make room for the arguments on the stack. */ | |
1083 | if (accumulate_size < arg_regs_size) | |
c5aa993b | 1084 | accumulate_size = arg_regs_size; |
c906108c SS |
1085 | sp -= accumulate_size; |
1086 | ||
1087 | /* Keep sp aligned to a multiple of 16 as the compiler does it too. */ | |
1088 | sp &= ~15; | |
1089 | ||
1090 | /* `Push' arguments on the stack. */ | |
c5aa993b JM |
1091 | for (i = nargs; m_arg--, --i >= 0;) |
1092 | write_memory (sp + m_arg->offset, m_arg->contents, m_arg->len); | |
c906108c SS |
1093 | if (struct_return) |
1094 | { | |
1095 | store_address (raw_buffer, sizeof (CORE_ADDR), struct_addr); | |
1096 | write_memory (sp, raw_buffer, sizeof (CORE_ADDR)); | |
1097 | } | |
1098 | ||
1099 | /* Load the argument registers. */ | |
1100 | for (i = 0; i < required_arg_regs; i++) | |
1101 | { | |
1102 | LONGEST val; | |
1103 | ||
1104 | val = read_memory_integer (sp + i * 8, 8); | |
1105 | write_register (A0_REGNUM + i, val); | |
1106 | write_register (FPA0_REGNUM + i, val); | |
1107 | } | |
1108 | ||
1109 | return sp + arg_regs_size; | |
1110 | } | |
1111 | ||
1112 | void | |
fba45db2 | 1113 | alpha_push_dummy_frame (void) |
c906108c SS |
1114 | { |
1115 | int ireg; | |
1116 | struct linked_proc_info *link; | |
1117 | alpha_extra_func_info_t proc_desc; | |
1118 | CORE_ADDR sp = read_register (SP_REGNUM); | |
1119 | CORE_ADDR save_address; | |
1120 | char raw_buffer[MAX_REGISTER_RAW_SIZE]; | |
1121 | unsigned long mask; | |
1122 | ||
c5aa993b | 1123 | link = (struct linked_proc_info *) xmalloc (sizeof (struct linked_proc_info)); |
c906108c SS |
1124 | link->next = linked_proc_desc_table; |
1125 | linked_proc_desc_table = link; | |
c5aa993b | 1126 | |
c906108c SS |
1127 | proc_desc = &link->info; |
1128 | ||
1129 | /* | |
1130 | * The registers we must save are all those not preserved across | |
1131 | * procedure calls. | |
1132 | * In addition, we must save the PC and RA. | |
1133 | * | |
1134 | * Dummy frame layout: | |
1135 | * (high memory) | |
c5aa993b | 1136 | * Saved PC |
c906108c SS |
1137 | * Saved F30 |
1138 | * ... | |
1139 | * Saved F0 | |
c5aa993b JM |
1140 | * Saved R29 |
1141 | * ... | |
1142 | * Saved R0 | |
1143 | * Saved R26 (RA) | |
1144 | * Parameter build area | |
c906108c SS |
1145 | * (low memory) |
1146 | */ | |
1147 | ||
1148 | /* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<31. */ | |
1149 | #define MASK(i,j) ((((LONGEST)1 << ((j)+1)) - 1) ^ (((LONGEST)1 << (i)) - 1)) | |
1150 | #define GEN_REG_SAVE_MASK (MASK(0,8) | MASK(16,29)) | |
1151 | #define GEN_REG_SAVE_COUNT 24 | |
1152 | #define FLOAT_REG_SAVE_MASK (MASK(0,1) | MASK(10,30)) | |
1153 | #define FLOAT_REG_SAVE_COUNT 23 | |
1154 | /* The special register is the PC as we have no bit for it in the save masks. | |
1155 | alpha_frame_saved_pc knows where the pc is saved in a dummy frame. */ | |
1156 | #define SPECIAL_REG_SAVE_COUNT 1 | |
1157 | ||
c5aa993b JM |
1158 | PROC_REG_MASK (proc_desc) = GEN_REG_SAVE_MASK; |
1159 | PROC_FREG_MASK (proc_desc) = FLOAT_REG_SAVE_MASK; | |
c906108c SS |
1160 | /* PROC_REG_OFFSET is the offset from the dummy frame to the saved RA, |
1161 | but keep SP aligned to a multiple of 16. */ | |
c5aa993b JM |
1162 | PROC_REG_OFFSET (proc_desc) = |
1163 | -((8 * (SPECIAL_REG_SAVE_COUNT | |
c906108c SS |
1164 | + GEN_REG_SAVE_COUNT |
1165 | + FLOAT_REG_SAVE_COUNT) | |
c5aa993b JM |
1166 | + 15) & ~15); |
1167 | PROC_FREG_OFFSET (proc_desc) = | |
1168 | PROC_REG_OFFSET (proc_desc) + 8 * GEN_REG_SAVE_COUNT; | |
c906108c SS |
1169 | |
1170 | /* Save general registers. | |
1171 | The return address register is the first saved register, all other | |
1172 | registers follow in ascending order. | |
1173 | The PC is saved immediately below the SP. */ | |
c5aa993b | 1174 | save_address = sp + PROC_REG_OFFSET (proc_desc); |
c906108c SS |
1175 | store_address (raw_buffer, 8, read_register (RA_REGNUM)); |
1176 | write_memory (save_address, raw_buffer, 8); | |
1177 | save_address += 8; | |
c5aa993b | 1178 | mask = PROC_REG_MASK (proc_desc) & 0xffffffffL; |
c906108c SS |
1179 | for (ireg = 0; mask; ireg++, mask >>= 1) |
1180 | if (mask & 1) | |
1181 | { | |
1182 | if (ireg == RA_REGNUM) | |
1183 | continue; | |
1184 | store_address (raw_buffer, 8, read_register (ireg)); | |
1185 | write_memory (save_address, raw_buffer, 8); | |
1186 | save_address += 8; | |
1187 | } | |
1188 | ||
1189 | store_address (raw_buffer, 8, read_register (PC_REGNUM)); | |
1190 | write_memory (sp - 8, raw_buffer, 8); | |
1191 | ||
1192 | /* Save floating point registers. */ | |
c5aa993b JM |
1193 | save_address = sp + PROC_FREG_OFFSET (proc_desc); |
1194 | mask = PROC_FREG_MASK (proc_desc) & 0xffffffffL; | |
c906108c SS |
1195 | for (ireg = 0; mask; ireg++, mask >>= 1) |
1196 | if (mask & 1) | |
1197 | { | |
1198 | store_address (raw_buffer, 8, read_register (ireg + FP0_REGNUM)); | |
1199 | write_memory (save_address, raw_buffer, 8); | |
1200 | save_address += 8; | |
1201 | } | |
1202 | ||
1203 | /* Set and save the frame address for the dummy. | |
1204 | This is tricky. The only registers that are suitable for a frame save | |
1205 | are those that are preserved across procedure calls (s0-s6). But if | |
1206 | a read system call is interrupted and then a dummy call is made | |
1207 | (see testsuite/gdb.t17/interrupt.exp) the dummy call hangs till the read | |
1208 | is satisfied. Then it returns with the s0-s6 registers set to the values | |
1209 | on entry to the read system call and our dummy frame pointer would be | |
1210 | destroyed. So we save the dummy frame in the proc_desc and handle the | |
1211 | retrieval of the frame pointer of a dummy specifically. The frame register | |
1212 | is set to the virtual frame (pseudo) register, it's value will always | |
1213 | be read as zero and will help us to catch any errors in the dummy frame | |
1214 | retrieval code. */ | |
c5aa993b JM |
1215 | PROC_DUMMY_FRAME (proc_desc) = sp; |
1216 | PROC_FRAME_REG (proc_desc) = FP_REGNUM; | |
1217 | PROC_FRAME_OFFSET (proc_desc) = 0; | |
1218 | sp += PROC_REG_OFFSET (proc_desc); | |
c906108c SS |
1219 | write_register (SP_REGNUM, sp); |
1220 | ||
c5aa993b JM |
1221 | PROC_LOW_ADDR (proc_desc) = CALL_DUMMY_ADDRESS (); |
1222 | PROC_HIGH_ADDR (proc_desc) = PROC_LOW_ADDR (proc_desc) + 4; | |
c906108c | 1223 | |
c5aa993b JM |
1224 | SET_PROC_DESC_IS_DUMMY (proc_desc); |
1225 | PROC_PC_REG (proc_desc) = RA_REGNUM; | |
c906108c SS |
1226 | } |
1227 | ||
1228 | void | |
fba45db2 | 1229 | alpha_pop_frame (void) |
c906108c SS |
1230 | { |
1231 | register int regnum; | |
1232 | struct frame_info *frame = get_current_frame (); | |
1233 | CORE_ADDR new_sp = frame->frame; | |
1234 | ||
140f9984 | 1235 | alpha_extra_func_info_t proc_desc = frame->extra_info->proc_desc; |
c906108c | 1236 | |
9e0b60a8 JM |
1237 | /* we need proc_desc to know how to restore the registers; |
1238 | if it is NULL, construct (a temporary) one */ | |
1239 | if (proc_desc == NULL) | |
c5aa993b | 1240 | proc_desc = find_proc_desc (frame->pc, frame->next); |
9e0b60a8 JM |
1241 | |
1242 | /* Question: should we copy this proc_desc and save it in | |
1243 | frame->proc_desc? If we do, who will free it? | |
1244 | For now, we don't save a copy... */ | |
1245 | ||
c5aa993b | 1246 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
c906108c SS |
1247 | if (frame->saved_regs == NULL) |
1248 | alpha_find_saved_regs (frame); | |
1249 | if (proc_desc) | |
1250 | { | |
c5aa993b JM |
1251 | for (regnum = 32; --regnum >= 0;) |
1252 | if (PROC_REG_MASK (proc_desc) & (1 << regnum)) | |
c906108c SS |
1253 | write_register (regnum, |
1254 | read_memory_integer (frame->saved_regs[regnum], | |
1255 | 8)); | |
c5aa993b JM |
1256 | for (regnum = 32; --regnum >= 0;) |
1257 | if (PROC_FREG_MASK (proc_desc) & (1 << regnum)) | |
c906108c | 1258 | write_register (regnum + FP0_REGNUM, |
c5aa993b | 1259 | read_memory_integer (frame->saved_regs[regnum + FP0_REGNUM], 8)); |
c906108c SS |
1260 | } |
1261 | write_register (SP_REGNUM, new_sp); | |
1262 | flush_cached_frames (); | |
1263 | ||
c5aa993b | 1264 | if (proc_desc && (PROC_DESC_IS_DUMMY (proc_desc) |
c906108c SS |
1265 | || PROC_DESC_IS_DYN_SIGTRAMP (proc_desc))) |
1266 | { | |
1267 | struct linked_proc_info *pi_ptr, *prev_ptr; | |
1268 | ||
1269 | for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL; | |
1270 | pi_ptr != NULL; | |
1271 | prev_ptr = pi_ptr, pi_ptr = pi_ptr->next) | |
1272 | { | |
1273 | if (&pi_ptr->info == proc_desc) | |
1274 | break; | |
1275 | } | |
1276 | ||
1277 | if (pi_ptr == NULL) | |
1278 | error ("Can't locate dummy extra frame info\n"); | |
1279 | ||
1280 | if (prev_ptr != NULL) | |
1281 | prev_ptr->next = pi_ptr->next; | |
1282 | else | |
1283 | linked_proc_desc_table = pi_ptr->next; | |
1284 | ||
b8c9b27d | 1285 | xfree (pi_ptr); |
c906108c SS |
1286 | } |
1287 | } | |
1288 | \f | |
1289 | /* To skip prologues, I use this predicate. Returns either PC itself | |
1290 | if the code at PC does not look like a function prologue; otherwise | |
1291 | returns an address that (if we're lucky) follows the prologue. If | |
1292 | LENIENT, then we must skip everything which is involved in setting | |
1293 | up the frame (it's OK to skip more, just so long as we don't skip | |
1294 | anything which might clobber the registers which are being saved. | |
0fb34c3a MS |
1295 | Currently we must not skip more on the alpha, but we might need the |
1296 | lenient stuff some day. */ | |
c906108c | 1297 | |
f8453e34 JT |
1298 | static CORE_ADDR |
1299 | alpha_skip_prologue_internal (CORE_ADDR pc, int lenient) | |
c906108c | 1300 | { |
c5aa993b JM |
1301 | unsigned long inst; |
1302 | int offset; | |
1303 | CORE_ADDR post_prologue_pc; | |
1304 | char buf[4]; | |
c906108c SS |
1305 | |
1306 | #ifdef GDB_TARGET_HAS_SHARED_LIBS | |
c5aa993b JM |
1307 | /* Silently return the unaltered pc upon memory errors. |
1308 | This could happen on OSF/1 if decode_line_1 tries to skip the | |
1309 | prologue for quickstarted shared library functions when the | |
1310 | shared library is not yet mapped in. | |
1311 | Reading target memory is slow over serial lines, so we perform | |
1312 | this check only if the target has shared libraries. */ | |
1313 | if (target_read_memory (pc, buf, 4)) | |
1314 | return pc; | |
c906108c SS |
1315 | #endif |
1316 | ||
c5aa993b JM |
1317 | /* See if we can determine the end of the prologue via the symbol table. |
1318 | If so, then return either PC, or the PC after the prologue, whichever | |
1319 | is greater. */ | |
c906108c | 1320 | |
c5aa993b | 1321 | post_prologue_pc = after_prologue (pc, NULL); |
c906108c | 1322 | |
c5aa993b JM |
1323 | if (post_prologue_pc != 0) |
1324 | return max (pc, post_prologue_pc); | |
c906108c | 1325 | |
c5aa993b JM |
1326 | /* Can't determine prologue from the symbol table, need to examine |
1327 | instructions. */ | |
c906108c | 1328 | |
c5aa993b JM |
1329 | /* Skip the typical prologue instructions. These are the stack adjustment |
1330 | instruction and the instructions that save registers on the stack | |
1331 | or in the gcc frame. */ | |
1332 | for (offset = 0; offset < 100; offset += 4) | |
1333 | { | |
1334 | int status; | |
1335 | ||
1336 | status = read_memory_nobpt (pc + offset, buf, 4); | |
1337 | if (status) | |
1338 | memory_error (status, pc + offset); | |
1339 | inst = extract_unsigned_integer (buf, 4); | |
1340 | ||
1341 | /* The alpha has no delay slots. But let's keep the lenient stuff, | |
1342 | we might need it for something else in the future. */ | |
1343 | if (lenient && 0) | |
1344 | continue; | |
1345 | ||
1346 | if ((inst & 0xffff0000) == 0x27bb0000) /* ldah $gp,n($t12) */ | |
1347 | continue; | |
1348 | if ((inst & 0xffff0000) == 0x23bd0000) /* lda $gp,n($gp) */ | |
1349 | continue; | |
1350 | if ((inst & 0xffff0000) == 0x23de0000) /* lda $sp,n($sp) */ | |
1351 | continue; | |
1352 | if ((inst & 0xffe01fff) == 0x43c0153e) /* subq $sp,n,$sp */ | |
1353 | continue; | |
1354 | ||
1355 | if ((inst & 0xfc1f0000) == 0xb41e0000 | |
1356 | && (inst & 0xffff0000) != 0xb7fe0000) | |
1357 | continue; /* stq reg,n($sp) */ | |
1358 | /* reg != $zero */ | |
1359 | if ((inst & 0xfc1f0000) == 0x9c1e0000 | |
1360 | && (inst & 0xffff0000) != 0x9ffe0000) | |
1361 | continue; /* stt reg,n($sp) */ | |
1362 | /* reg != $zero */ | |
1363 | if (inst == 0x47de040f) /* bis sp,sp,fp */ | |
1364 | continue; | |
1365 | ||
1366 | break; | |
c906108c | 1367 | } |
c5aa993b | 1368 | return pc + offset; |
c906108c SS |
1369 | } |
1370 | ||
f8453e34 JT |
1371 | CORE_ADDR |
1372 | alpha_skip_prologue (CORE_ADDR addr) | |
1373 | { | |
1374 | return (alpha_skip_prologue_internal (addr, 0)); | |
1375 | } | |
1376 | ||
c906108c SS |
1377 | #if 0 |
1378 | /* Is address PC in the prologue (loosely defined) for function at | |
1379 | STARTADDR? */ | |
1380 | ||
1381 | static int | |
fba45db2 | 1382 | alpha_in_lenient_prologue (CORE_ADDR startaddr, CORE_ADDR pc) |
c906108c | 1383 | { |
f8453e34 | 1384 | CORE_ADDR end_prologue = alpha_skip_prologue_internal (startaddr, 1); |
c906108c SS |
1385 | return pc >= startaddr && pc < end_prologue; |
1386 | } | |
1387 | #endif | |
1388 | ||
1389 | /* The alpha needs a conversion between register and memory format if | |
1390 | the register is a floating point register and | |
c5aa993b | 1391 | memory format is float, as the register format must be double |
c906108c | 1392 | or |
c5aa993b JM |
1393 | memory format is an integer with 4 bytes or less, as the representation |
1394 | of integers in floating point registers is different. */ | |
c906108c | 1395 | void |
fba45db2 KB |
1396 | alpha_register_convert_to_virtual (int regnum, struct type *valtype, |
1397 | char *raw_buffer, char *virtual_buffer) | |
c906108c SS |
1398 | { |
1399 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1400 | { | |
1401 | memcpy (virtual_buffer, raw_buffer, REGISTER_VIRTUAL_SIZE (regnum)); | |
1402 | return; | |
1403 | } | |
1404 | ||
1405 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1406 | { | |
1407 | double d = extract_floating (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1408 | store_floating (virtual_buffer, TYPE_LENGTH (valtype), d); | |
1409 | } | |
1410 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1411 | { | |
1412 | ULONGEST l; | |
1413 | l = extract_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum)); | |
1414 | l = ((l >> 32) & 0xc0000000) | ((l >> 29) & 0x3fffffff); | |
1415 | store_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype), l); | |
1416 | } | |
1417 | else | |
1418 | error ("Cannot retrieve value from floating point register"); | |
1419 | } | |
1420 | ||
1421 | void | |
fba45db2 KB |
1422 | alpha_register_convert_to_raw (struct type *valtype, int regnum, |
1423 | char *virtual_buffer, char *raw_buffer) | |
c906108c SS |
1424 | { |
1425 | if (TYPE_LENGTH (valtype) >= REGISTER_RAW_SIZE (regnum)) | |
1426 | { | |
1427 | memcpy (raw_buffer, virtual_buffer, REGISTER_RAW_SIZE (regnum)); | |
1428 | return; | |
1429 | } | |
1430 | ||
1431 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1432 | { | |
1433 | double d = extract_floating (virtual_buffer, TYPE_LENGTH (valtype)); | |
1434 | store_floating (raw_buffer, REGISTER_RAW_SIZE (regnum), d); | |
1435 | } | |
1436 | else if (TYPE_CODE (valtype) == TYPE_CODE_INT && TYPE_LENGTH (valtype) <= 4) | |
1437 | { | |
1438 | ULONGEST l; | |
1439 | if (TYPE_UNSIGNED (valtype)) | |
1440 | l = extract_unsigned_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1441 | else | |
1442 | l = extract_signed_integer (virtual_buffer, TYPE_LENGTH (valtype)); | |
1443 | l = ((l & 0xc0000000) << 32) | ((l & 0x3fffffff) << 29); | |
1444 | store_unsigned_integer (raw_buffer, REGISTER_RAW_SIZE (regnum), l); | |
1445 | } | |
1446 | else | |
1447 | error ("Cannot store value in floating point register"); | |
1448 | } | |
1449 | ||
1450 | /* Given a return value in `regbuf' with a type `valtype', | |
1451 | extract and copy its value into `valbuf'. */ | |
1452 | ||
1453 | void | |
732a6b2d KB |
1454 | alpha_extract_return_value (struct type *valtype, |
1455 | char regbuf[REGISTER_BYTES], char *valbuf) | |
c906108c SS |
1456 | { |
1457 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) | |
1458 | alpha_register_convert_to_virtual (FP0_REGNUM, valtype, | |
1459 | regbuf + REGISTER_BYTE (FP0_REGNUM), | |
1460 | valbuf); | |
1461 | else | |
1462 | memcpy (valbuf, regbuf + REGISTER_BYTE (V0_REGNUM), TYPE_LENGTH (valtype)); | |
1463 | } | |
1464 | ||
1465 | /* Given a return value in `regbuf' with a type `valtype', | |
1466 | write its value into the appropriate register. */ | |
1467 | ||
1468 | void | |
fba45db2 | 1469 | alpha_store_return_value (struct type *valtype, char *valbuf) |
c906108c SS |
1470 | { |
1471 | char raw_buffer[MAX_REGISTER_RAW_SIZE]; | |
1472 | int regnum = V0_REGNUM; | |
1473 | int length = TYPE_LENGTH (valtype); | |
c5aa993b | 1474 | |
c906108c SS |
1475 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) |
1476 | { | |
1477 | regnum = FP0_REGNUM; | |
1478 | length = REGISTER_RAW_SIZE (regnum); | |
1479 | alpha_register_convert_to_raw (valtype, regnum, valbuf, raw_buffer); | |
1480 | } | |
1481 | else | |
1482 | memcpy (raw_buffer, valbuf, length); | |
1483 | ||
1484 | write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, length); | |
1485 | } | |
1486 | ||
1487 | /* Just like reinit_frame_cache, but with the right arguments to be | |
1488 | callable as an sfunc. */ | |
1489 | ||
1490 | static void | |
fba45db2 | 1491 | reinit_frame_cache_sfunc (char *args, int from_tty, struct cmd_list_element *c) |
c906108c SS |
1492 | { |
1493 | reinit_frame_cache (); | |
1494 | } | |
1495 | ||
1496 | /* This is the definition of CALL_DUMMY_ADDRESS. It's a heuristic that is used | |
1497 | to find a convenient place in the text segment to stick a breakpoint to | |
1498 | detect the completion of a target function call (ala call_function_by_hand). | |
1499 | */ | |
1500 | ||
1501 | CORE_ADDR | |
fba45db2 | 1502 | alpha_call_dummy_address (void) |
c906108c SS |
1503 | { |
1504 | CORE_ADDR entry; | |
1505 | struct minimal_symbol *sym; | |
1506 | ||
1507 | entry = entry_point_address (); | |
1508 | ||
1509 | if (entry != 0) | |
1510 | return entry; | |
1511 | ||
1512 | sym = lookup_minimal_symbol ("_Prelude", NULL, symfile_objfile); | |
1513 | ||
1514 | if (!sym || MSYMBOL_TYPE (sym) != mst_text) | |
1515 | return 0; | |
1516 | else | |
1517 | return SYMBOL_VALUE_ADDRESS (sym) + 4; | |
ec32e4be JT |
1518 | } |
1519 | ||
0d056799 JT |
1520 | void |
1521 | alpha_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs, | |
1522 | struct value **args, struct type *type, int gcc_p) | |
1523 | { | |
1524 | CORE_ADDR bp_address = CALL_DUMMY_ADDRESS (); | |
1525 | ||
1526 | if (bp_address == 0) | |
1527 | error ("no place to put call"); | |
1528 | write_register (RA_REGNUM, bp_address); | |
1529 | write_register (T12_REGNUM, fun); | |
1530 | } | |
1531 | ||
ee1f65f0 JT |
1532 | /* On the Alpha, the call dummy code is nevery copied to user space |
1533 | (see alpha_fix_call_dummy() above). The contents of this do not | |
1534 | matter. */ | |
1535 | LONGEST alpha_call_dummy_words[] = { 0 }; | |
1536 | ||
d734c450 JT |
1537 | int |
1538 | alpha_use_struct_convention (int gcc_p, struct type *type) | |
1539 | { | |
1540 | /* Structures are returned by ref in extra arg0. */ | |
1541 | return 1; | |
1542 | } | |
1543 | ||
0d056799 JT |
1544 | void |
1545 | alpha_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) | |
1546 | { | |
1547 | /* Store the address of the place in which to copy the structure the | |
1548 | subroutine will return. Handled by alpha_push_arguments. */ | |
1549 | } | |
1550 | ||
1551 | CORE_ADDR | |
1552 | alpha_extract_struct_value_address (char *regbuf) | |
1553 | { | |
1554 | return (extract_address (regbuf + REGISTER_BYTE (V0_REGNUM), | |
1555 | REGISTER_RAW_SIZE (V0_REGNUM))); | |
1556 | } | |
1557 | ||
ec32e4be JT |
1558 | /* alpha_software_single_step() is called just before we want to resume |
1559 | the inferior, if we want to single-step it but there is no hardware | |
1560 | or kernel single-step support (NetBSD on Alpha, for example). We find | |
1561 | the target of the coming instruction and breakpoint it. | |
1562 | ||
1563 | single_step is also called just after the inferior stops. If we had | |
1564 | set up a simulated single-step, we undo our damage. */ | |
1565 | ||
1566 | static CORE_ADDR | |
1567 | alpha_next_pc (CORE_ADDR pc) | |
1568 | { | |
1569 | unsigned int insn; | |
1570 | unsigned int op; | |
1571 | int offset; | |
1572 | LONGEST rav; | |
1573 | ||
1574 | insn = read_memory_unsigned_integer (pc, sizeof (insn)); | |
1575 | ||
1576 | /* Opcode is top 6 bits. */ | |
1577 | op = (insn >> 26) & 0x3f; | |
1578 | ||
1579 | if (op == 0x1a) | |
1580 | { | |
1581 | /* Jump format: target PC is: | |
1582 | RB & ~3 */ | |
1583 | return (read_register ((insn >> 16) & 0x1f) & ~3); | |
1584 | } | |
1585 | ||
1586 | if ((op & 0x30) == 0x30) | |
1587 | { | |
1588 | /* Branch format: target PC is: | |
1589 | (new PC) + (4 * sext(displacement)) */ | |
1590 | if (op == 0x30 || /* BR */ | |
1591 | op == 0x34) /* BSR */ | |
1592 | { | |
1593 | branch_taken: | |
1594 | offset = (insn & 0x001fffff); | |
1595 | if (offset & 0x00100000) | |
1596 | offset |= 0xffe00000; | |
1597 | offset *= 4; | |
1598 | return (pc + 4 + offset); | |
1599 | } | |
1600 | ||
1601 | /* Need to determine if branch is taken; read RA. */ | |
1602 | rav = (LONGEST) read_register ((insn >> 21) & 0x1f); | |
1603 | switch (op) | |
1604 | { | |
1605 | case 0x38: /* BLBC */ | |
1606 | if ((rav & 1) == 0) | |
1607 | goto branch_taken; | |
1608 | break; | |
1609 | case 0x3c: /* BLBS */ | |
1610 | if (rav & 1) | |
1611 | goto branch_taken; | |
1612 | break; | |
1613 | case 0x39: /* BEQ */ | |
1614 | if (rav == 0) | |
1615 | goto branch_taken; | |
1616 | break; | |
1617 | case 0x3d: /* BNE */ | |
1618 | if (rav != 0) | |
1619 | goto branch_taken; | |
1620 | break; | |
1621 | case 0x3a: /* BLT */ | |
1622 | if (rav < 0) | |
1623 | goto branch_taken; | |
1624 | break; | |
1625 | case 0x3b: /* BLE */ | |
1626 | if (rav <= 0) | |
1627 | goto branch_taken; | |
1628 | break; | |
1629 | case 0x3f: /* BGT */ | |
1630 | if (rav > 0) | |
1631 | goto branch_taken; | |
1632 | break; | |
1633 | case 0x3e: /* BGE */ | |
1634 | if (rav >= 0) | |
1635 | goto branch_taken; | |
1636 | break; | |
1637 | } | |
1638 | } | |
1639 | ||
1640 | /* Not a branch or branch not taken; target PC is: | |
1641 | pc + 4 */ | |
1642 | return (pc + 4); | |
1643 | } | |
1644 | ||
1645 | void | |
1646 | alpha_software_single_step (enum target_signal sig, int insert_breakpoints_p) | |
1647 | { | |
1648 | static CORE_ADDR next_pc; | |
1649 | typedef char binsn_quantum[BREAKPOINT_MAX]; | |
1650 | static binsn_quantum break_mem; | |
1651 | CORE_ADDR pc; | |
1652 | ||
1653 | if (insert_breakpoints_p) | |
1654 | { | |
1655 | pc = read_pc (); | |
1656 | next_pc = alpha_next_pc (pc); | |
1657 | ||
1658 | target_insert_breakpoint (next_pc, break_mem); | |
1659 | } | |
1660 | else | |
1661 | { | |
1662 | target_remove_breakpoint (next_pc, break_mem); | |
1663 | write_pc (next_pc); | |
1664 | } | |
c906108c SS |
1665 | } |
1666 | ||
1667 | void | |
fba45db2 | 1668 | _initialize_alpha_tdep (void) |
c906108c SS |
1669 | { |
1670 | struct cmd_list_element *c; | |
1671 | ||
1672 | tm_print_insn = print_insn_alpha; | |
1673 | ||
1674 | /* Let the user set the fence post for heuristic_proc_start. */ | |
1675 | ||
1676 | /* We really would like to have both "0" and "unlimited" work, but | |
1677 | command.c doesn't deal with that. So make it a var_zinteger | |
1678 | because the user can always use "999999" or some such for unlimited. */ | |
1679 | c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger, | |
1680 | (char *) &heuristic_fence_post, | |
1681 | "\ | |
1682 | Set the distance searched for the start of a function.\n\ | |
1683 | If you are debugging a stripped executable, GDB needs to search through the\n\ | |
1684 | program for the start of a function. This command sets the distance of the\n\ | |
1685 | search. The only need to set it is when debugging a stripped executable.", | |
1686 | &setlist); | |
1687 | /* We need to throw away the frame cache when we set this, since it | |
1688 | might change our ability to get backtraces. */ | |
1689 | c->function.sfunc = reinit_frame_cache_sfunc; | |
1690 | add_show_from_set (c, &showlist); | |
1691 | } |