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[deliverable/binutils-gdb.git] / gdb / s390-tdep.c
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5769d3cd
AC		 1/* Target-dependent code for GDB, the GNU debugger.
2 Copyright 2001 Free Software Foundation, Inc.
3 Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
4 for IBM Deutschland Entwicklung GmbH, IBM Corporation.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21 02111-1307, USA. */
22
23#define S390_TDEP /* for special macros in tm-s390.h */
24#include <defs.h>
25#include "arch-utils.h"
26#include "frame.h"
27#include "inferior.h"
28#include "symtab.h"
29#include "target.h"
30#include "gdbcore.h"
31#include "gdbcmd.h"
32#include "symfile.h"
33#include "objfiles.h"
34#include "tm.h"
35#include "../bfd/bfd.h"
36#include "floatformat.h"
37#include "regcache.h"
fd0407d6 38#include "value.h"
78f8b424 39#include "gdb_assert.h"
5769d3cd
AC		 40
41
42
60e6cc42 43
5769d3cd
AC		 44/* Number of bytes of storage in the actual machine representation
45 for register N.
46 Note that the unsigned cast here forces the result of the
47 subtraction to very high positive values if N < S390_FP0_REGNUM */
48int
49s390_register_raw_size (int reg_nr)
50{
51 return ((unsigned) reg_nr - S390_FP0_REGNUM) <
52 S390_NUM_FPRS ? S390_FPR_SIZE : 4;
53}
54
55int
56s390x_register_raw_size (int reg_nr)
57{
58 return (reg_nr == S390_FPC_REGNUM)
59 || (reg_nr >= S390_FIRST_ACR && reg_nr <= S390_LAST_ACR) ? 4 : 8;
60}
61
62int
63s390_cannot_fetch_register (int regno)
64{
65 return (regno >= S390_FIRST_CR && regno < (S390_FIRST_CR + 9)) ||
66 (regno >= (S390_FIRST_CR + 12) && regno <= S390_LAST_CR);
67}
68
69int
70s390_register_byte (int reg_nr)
71{
72 if (reg_nr <= S390_GP_LAST_REGNUM)
73 return reg_nr * S390_GPR_SIZE;
74 if (reg_nr <= S390_LAST_ACR)
75 return S390_ACR0_OFFSET + (((reg_nr) - S390_FIRST_ACR) * S390_ACR_SIZE);
76 if (reg_nr <= S390_LAST_CR)
77 return S390_CR0_OFFSET + (((reg_nr) - S390_FIRST_CR) * S390_CR_SIZE);
78 if (reg_nr == S390_FPC_REGNUM)
79 return S390_FPC_OFFSET;
80 else
81 return S390_FP0_OFFSET + (((reg_nr) - S390_FP0_REGNUM) * S390_FPR_SIZE);
82}
83
84#ifndef GDBSERVER
85#define S390_MAX_INSTR_SIZE (6)
86#define S390_SYSCALL_OPCODE (0x0a)
87#define S390_SYSCALL_SIZE (2)
88#define S390_SIGCONTEXT_SREGS_OFFSET (8)
89#define S390X_SIGCONTEXT_SREGS_OFFSET (8)
90#define S390_SIGREGS_FP0_OFFSET (144)
91#define S390X_SIGREGS_FP0_OFFSET (216)
92#define S390_UC_MCONTEXT_OFFSET (256)
93#define S390X_UC_MCONTEXT_OFFSET (344)
94#define S390_STACK_FRAME_OVERHEAD (GDB_TARGET_IS_ESAME ? 160:96)
95#define S390_SIGNAL_FRAMESIZE (GDB_TARGET_IS_ESAME ? 160:96)
96#define s390_NR_sigreturn 119
97#define s390_NR_rt_sigreturn 173
98
99
100
101struct frame_extra_info
102{
103 int initialised;
104 int good_prologue;
105 CORE_ADDR function_start;
106 CORE_ADDR skip_prologue_function_start;
107 CORE_ADDR saved_pc_valid;
108 CORE_ADDR saved_pc;
109 CORE_ADDR sig_fixed_saved_pc_valid;
110 CORE_ADDR sig_fixed_saved_pc;
111 CORE_ADDR frame_pointer_saved_pc; /* frame pointer needed for alloca */
112 CORE_ADDR stack_bought; /* amount we decrement the stack pointer by */
113 CORE_ADDR sigcontext;
114};
115
116
117static CORE_ADDR s390_frame_saved_pc_nofix (struct frame_info *fi);
118
119int
120s390_readinstruction (bfd_byte instr[], CORE_ADDR at,
121 struct disassemble_info *info)
122{
123 int instrlen;
124
125 static int s390_instrlen[] = {
126 2,
127 4,
128 4,
129 6
130 };
131 if ((*info->read_memory_func) (at, &instr[0], 2, info))
132 return -1;
133 instrlen = s390_instrlen[instr[0] >> 6];
134 if ((*info->read_memory_func) (at + 2, &instr[2], instrlen - 2, info))
135 return -1;
136 return instrlen;
137}
138
139static void
140s390_memset_extra_info (struct frame_extra_info *fextra_info)
141{
142 memset (fextra_info, 0, sizeof (struct frame_extra_info));
143}
144
145
146
147char *
148s390_register_name (int reg_nr)
149{
150 static char *register_names[] = {
151 "pswm", "pswa",
4ed90530
JB		 152 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
153 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
5769d3cd
AC		 154 "acr0", "acr1", "acr2", "acr3", "acr4", "acr5", "acr6", "acr7",
155 "acr8", "acr9", "acr10", "acr11", "acr12", "acr13", "acr14", "acr15",
156 "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7",
157 "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15",
158 "fpc",
4ed90530
JB		 159 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
160 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15"
5769d3cd
AC		 161 };
162
163 if (reg_nr >= S390_LAST_REGNUM)
164 return NULL;
165 return register_names[reg_nr];
166}
167
168
169
170
171int
172s390_stab_reg_to_regnum (int regno)
173{
174 return regno >= 64 ? S390_PSWM_REGNUM - 64 :
175 regno >= 48 ? S390_FIRST_ACR - 48 :
176 regno >= 32 ? S390_FIRST_CR - 32 :
177 regno <= 15 ? (regno + 2) :
178 S390_FP0_REGNUM + ((regno - 16) & 8) + (((regno - 16) & 3) << 1) +
179 (((regno - 16) & 4) >> 2);
180}
181
182
183
184/* s390_get_frame_info based on Hartmuts
185 prologue definition in
186 gcc-2.8.1/config/l390/linux.c
187
188 It reads one instruction at a time & based on whether
189 it looks like prologue code or not it makes a decision on
190 whether the prologue is over, there are various state machines
191 in the code to determine if the prologue code is possilby valid.
192
193 This is done to hopefully allow the code survive minor revs of
194 calling conventions.
195
196 */
197
198int
199s390_get_frame_info (CORE_ADDR pc, struct frame_extra_info *fextra_info,
200 struct frame_info *fi, int init_extra_info)
201{
202#define CONST_POOL_REGIDX 13
203#define GOT_REGIDX 12
204 bfd_byte instr[S390_MAX_INSTR_SIZE];
205 CORE_ADDR test_pc = pc, test_pc2;
206 CORE_ADDR orig_sp = 0, save_reg_addr = 0, *saved_regs = NULL;
207 int valid_prologue, good_prologue = 0;
208 int gprs_saved[S390_NUM_GPRS];
209 int fprs_saved[S390_NUM_FPRS];
210 int regidx, instrlen;
211 int save_link_regidx, subtract_sp_regidx;
8ac0e65a 212 int const_pool_state, save_link_state;
5769d3cd
AC		 213 int frame_pointer_found, varargs_state;
214 int loop_cnt, gdb_gpr_store, gdb_fpr_store;
215 int frame_pointer_regidx = 0xf;
216 int offset, expected_offset;
217 int err = 0;
218 disassemble_info info;
8ac0e65a
JB		 219
220 /* What we've seen so far regarding r12 --- the GOT (Global Offset
221 Table) pointer. We expect to see `l %r12, N(%r13)', which loads
222 r12 with the offset from the constant pool to the GOT, and then
223 an `ar %r12, %r13', which adds the constant pool address,
224 yielding the GOT's address. Here's what got_state means:
225 0 -- seen nothing
226 1 -- seen `l %r12, N(%r13)', but no `ar'
227 2 -- seen load and add, so GOT pointer is totally initialized
228 When got_state is 1, then got_load_addr is the address of the
229 load instruction, and got_load_len is the length of that
230 instruction. */
231 int got_state;
64f9bb98 232 CORE_ADDR got_load_addr = 0, got_load_len = 0;
8ac0e65a 233
5769d3cd
AC		 234 const_pool_state = save_link_state = got_state = varargs_state = 0;
235 frame_pointer_found = 0;
236 memset (gprs_saved, 0, sizeof (gprs_saved));
237 memset (fprs_saved, 0, sizeof (fprs_saved));
238 info.read_memory_func = dis_asm_read_memory;
239
240 save_link_regidx = subtract_sp_regidx = 0;
241 if (fextra_info)
242 {
243 if (fi && fi->frame)
244 {
245 orig_sp = fi->frame + fextra_info->stack_bought;
246 saved_regs = fi->saved_regs;
247 }
248 if (init_extra_info || !fextra_info->initialised)
249 {
250 s390_memset_extra_info (fextra_info);
251 fextra_info->function_start = pc;
252 fextra_info->initialised = 1;
253 }
254 }
255 instrlen = 0;
256 do
257 {
258 valid_prologue = 0;
259 test_pc += instrlen;
260 /* add the previous instruction len */
261 instrlen = s390_readinstruction (instr, test_pc, &info);
262 if (instrlen < 0)
263 {
264 good_prologue = 0;
265 err = -1;
266 break;
267 }
268 /* We probably are in a glibc syscall */
269 if (instr[0] == S390_SYSCALL_OPCODE && test_pc == pc)
270 {
271 good_prologue = 1;
272 if (saved_regs && fextra_info && fi->next && fi->next->extra_info
273 && fi->next->extra_info->sigcontext)
274 {
275 /* We are backtracing from a signal handler */
276 save_reg_addr = fi->next->extra_info->sigcontext +
277 REGISTER_BYTE (S390_GP0_REGNUM);
278 for (regidx = 0; regidx < S390_NUM_GPRS; regidx++)
279 {
280 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
281 save_reg_addr += S390_GPR_SIZE;
282 }
283 save_reg_addr = fi->next->extra_info->sigcontext +
284 (GDB_TARGET_IS_ESAME ? S390X_SIGREGS_FP0_OFFSET :
285 S390_SIGREGS_FP0_OFFSET);
286 for (regidx = 0; regidx < S390_NUM_FPRS; regidx++)
287 {
288 saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
289 save_reg_addr += S390_FPR_SIZE;
290 }
291 }
292 break;
293 }
294 if (save_link_state == 0)
295 {
296 /* check for a stack relative STMG or STM */
297 if (((GDB_TARGET_IS_ESAME &&
298 ((instr[0] == 0xeb) && (instr[5] == 0x24))) ||
299 (instr[0] == 0x90)) && ((instr[2] >> 4) == 0xf))
300 {
301 regidx = (instr[1] >> 4);
302 if (regidx < 6)
303 varargs_state = 1;
304 offset = ((instr[2] & 0xf) << 8) + instr[3];
305 expected_offset =
306 S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
307 if (offset != expected_offset)
308 {
309 good_prologue = 0;
310 break;
311 }
312 if (saved_regs)
313 save_reg_addr = orig_sp + offset;
314 for (; regidx <= (instr[1] & 0xf); regidx++)
315 {
316 if (gprs_saved[regidx])
317 {
318 good_prologue = 0;
319 break;
320 }
321 good_prologue = 1;
322 gprs_saved[regidx] = 1;
323 if (saved_regs)
324 {
325 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
326 save_reg_addr += S390_GPR_SIZE;
327 }
328 }
329 valid_prologue = 1;
330 continue;
331 }
332 }
333 /* check for a stack relative STG or ST */
334 if ((save_link_state == 0 || save_link_state == 3) &&
335 ((GDB_TARGET_IS_ESAME &&
336 ((instr[0] == 0xe3) && (instr[5] == 0x24))) ||
337 (instr[0] == 0x50)) && ((instr[2] >> 4) == 0xf))
338 {
339 regidx = instr[1] >> 4;
340 offset = ((instr[2] & 0xf) << 8) + instr[3];
341 if (offset == 0)
342 {
343 if (save_link_state == 3 && regidx == save_link_regidx)
344 {
345 save_link_state = 4;
346 valid_prologue = 1;
347 continue;
348 }
349 else
350 break;
351 }
352 if (regidx < 6)
353 varargs_state = 1;
354 expected_offset =
355 S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
356 if (offset != expected_offset)
357 {
358 good_prologue = 0;
359 break;
360 }
361 if (gprs_saved[regidx])
362 {
363 good_prologue = 0;
364 break;
365 }
366 good_prologue = 1;
367 gprs_saved[regidx] = 1;
368 if (saved_regs)
369 {
370 save_reg_addr = orig_sp + offset;
371 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
372 }
373 valid_prologue = 1;
374 continue;
375 }
376
377 /* check for STD */
378 if (instr[0] == 0x60 && (instr[2] >> 4) == 0xf)
379 {
380 regidx = instr[1] >> 4;
381 if (regidx == 0 || regidx == 2)
382 varargs_state = 1;
383 if (fprs_saved[regidx])
384 {
385 good_prologue = 0;
386 break;
387 }
388 fprs_saved[regidx] = 1;
389 if (saved_regs)
390 {
391 save_reg_addr = orig_sp + (((instr[2] & 0xf) << 8) + instr[3]);
392 saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
393 }
394 valid_prologue = 1;
395 continue;
396 }
397
398
399 if (const_pool_state == 0)
400 {
401
402 if (GDB_TARGET_IS_ESAME)
403 {
404 /* Check for larl CONST_POOL_REGIDX,offset on ESAME */
405 if ((instr[0] == 0xc0)
406 && (instr[1] == (CONST_POOL_REGIDX << 4)))
407 {
408 const_pool_state = 2;
409 valid_prologue = 1;
410 continue;
411 }
412 }
413 else
414 {
415 /* Check for BASR gpr13,gpr0 used to load constant pool pointer to r13 in old compiler */
416 if (instr[0] == 0xd && (instr[1] & 0xf) == 0
417 && ((instr[1] >> 4) == CONST_POOL_REGIDX))
418 {
419 const_pool_state = 1;
420 valid_prologue = 1;
421 continue;
422 }
423 }
424 /* Check for new fangled bras %r13,newpc to load new constant pool */
425 /* embedded in code, older pre abi compilers also emitted this stuff. */
426 if ((instr[0] == 0xa7) && ((instr[1] & 0xf) == 0x5) &&
427 ((instr[1] >> 4) == CONST_POOL_REGIDX)
428 && ((instr[2] & 0x80) == 0))
429 {
430 const_pool_state = 2;
431 test_pc +=
432 (((((instr[2] & 0xf) << 8) + instr[3]) << 1) - instrlen);
433 valid_prologue = 1;
434 continue;
435 }
436 }
437 /* Check for AGHI or AHI CONST_POOL_REGIDX,val */
438 if (const_pool_state == 1 && (instr[0] == 0xa7) &&
439 ((GDB_TARGET_IS_ESAME &&
440 (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xb))) ||
441 (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xa))))
442 {
443 const_pool_state = 2;
444 valid_prologue = 1;
445 continue;
446 }
447 /* Check for LGR or LR gprx,15 */
448 if ((GDB_TARGET_IS_ESAME &&
449 instr[0] == 0xb9 && instr[1] == 0x04 && (instr[3] & 0xf) == 0xf) ||
450 (instr[0] == 0x18 && (instr[1] & 0xf) == 0xf))
451 {
452 if (GDB_TARGET_IS_ESAME)
453 regidx = instr[3] >> 4;
454 else
455 regidx = instr[1] >> 4;
456 if (save_link_state == 0 && regidx != 0xb)
457 {
458 /* Almost defintely code for
459 decrementing the stack pointer
460 ( i.e. a non leaf function
461 or else leaf with locals ) */
462 save_link_regidx = regidx;
463 save_link_state = 1;
464 valid_prologue = 1;
465 continue;
466 }
467 /* We use this frame pointer for alloca
468 unfortunately we need to assume its gpr11
469 otherwise we would need a smarter prologue
470 walker. */
471 if (!frame_pointer_found && regidx == 0xb)
472 {
473 frame_pointer_regidx = 0xb;
474 frame_pointer_found = 1;
475 if (fextra_info)
476 fextra_info->frame_pointer_saved_pc = test_pc;
477 valid_prologue = 1;
478 continue;
479 }
480 }
481 /* Check for AHI or AGHI gpr15,val */
482 if (save_link_state == 1 && (instr[0] == 0xa7) &&
483 ((GDB_TARGET_IS_ESAME && (instr[1] == 0xfb)) || (instr[1] == 0xfa)))
484 {
485 if (fextra_info)
486 fextra_info->stack_bought =
487 -extract_signed_integer (&instr[2], 2);
488 save_link_state = 3;
489 valid_prologue = 1;
490 continue;
491 }
492 /* Alternatively check for the complex construction for
493 buying more than 32k of stack
494 BRAS gprx,.+8
495 long vals %r15,0(%gprx) gprx currently r1 */
496 if ((save_link_state == 1) && (instr[0] == 0xa7)
497 && ((instr[1] & 0xf) == 0x5) && (instr[2] == 0)
498 && (instr[3] == 0x4) && ((instr[1] >> 4) != CONST_POOL_REGIDX))
499 {
500 subtract_sp_regidx = instr[1] >> 4;
501 save_link_state = 2;
502 if (fextra_info)
503 target_read_memory (test_pc + instrlen,
504 (char *) &fextra_info->stack_bought,
505 sizeof (fextra_info->stack_bought));
506 test_pc += 4;
507 valid_prologue = 1;
508 continue;
509 }
510 if (save_link_state == 2 && instr[0] == 0x5b
511 && instr[1] == 0xf0 &&
512 instr[2] == (subtract_sp_regidx << 4) && instr[3] == 0)
513 {
514 save_link_state = 3;
515 valid_prologue = 1;
516 continue;
517 }
518 /* check for LA gprx,offset(15) used for varargs */
519 if ((instr[0] == 0x41) && ((instr[2] >> 4) == 0xf) &&
520 ((instr[1] & 0xf) == 0))
521 {
522 /* some code uses gpr7 to point to outgoing args */
523 if (((instr[1] >> 4) == 7) && (save_link_state == 0) &&
524 ((instr[2] & 0xf) == 0)
525 && (instr[3] == S390_STACK_FRAME_OVERHEAD))
526 {
527 valid_prologue = 1;
528 continue;
529 }
530 if (varargs_state == 1)
531 {
532 varargs_state = 2;
533 valid_prologue = 1;
534 continue;
535 }
536 }
537 /* Check for a GOT load */
538
539 if (GDB_TARGET_IS_ESAME)
540 {
541 /* Check for larl GOT_REGIDX, on ESAME */
542 if ((got_state == 0) && (instr[0] == 0xc0)
543 && (instr[1] == (GOT_REGIDX << 4)))
544 {
545 got_state = 2;
546 valid_prologue = 1;
547 continue;
548 }
549 }
550 else
551 {
552 /* check for l GOT_REGIDX,x(CONST_POOL_REGIDX) */
553 if (got_state == 0 && const_pool_state == 2 && instr[0] == 0x58
554 && (instr[2] == (CONST_POOL_REGIDX << 4))
555 && ((instr[1] >> 4) == GOT_REGIDX))
556 {
8ac0e65a
JB		 557 got_state = 1;
558 got_load_addr = test_pc;
559 got_load_len = instrlen;
5769d3cd
AC		 560 valid_prologue = 1;
561 continue;
562 }
563 /* Check for subsequent ar got_regidx,basr_regidx */
564 if (got_state == 1 && instr[0] == 0x1a &&
565 instr[1] == ((GOT_REGIDX << 4) | CONST_POOL_REGIDX))
566 {
567 got_state = 2;
568 valid_prologue = 1;
569 continue;
570 }
571 }
572 }
573 while (valid_prologue && good_prologue);
574 if (good_prologue)
575 {
8ac0e65a
JB		 576 /* If this function doesn't reference the global offset table,
577 then the compiler may use r12 for other things. If the last
578 instruction we saw was a load of r12 from the constant pool,
579 with no subsequent add to make the address PC-relative, then
580 the load was probably a genuine body instruction; don't treat
581 it as part of the prologue. */
582 if (got_state == 1
583 && got_load_addr + got_load_len == test_pc)
584 {
585 test_pc = got_load_addr;
586 instrlen = got_load_len;
587 }
588
589 good_prologue = (((const_pool_state == 0) || (const_pool_state == 2)) &&
5769d3cd
AC		 590 ((save_link_state == 0) || (save_link_state == 4)) &&
591 ((varargs_state == 0) || (varargs_state == 2)));
592 }
593 if (fextra_info)
594 {
595 fextra_info->good_prologue = good_prologue;
596 fextra_info->skip_prologue_function_start =
597 (good_prologue ? test_pc : pc);
598 }
09025237
JB		 599 if (saved_regs)
600 /* The SP's element of the saved_regs array holds the old SP,
601 not the address at which it is saved. */
602 saved_regs[S390_SP_REGNUM] = orig_sp;
5769d3cd
AC		 603 return err;
604}
605
606
607int
608s390_check_function_end (CORE_ADDR pc)
609{
610 bfd_byte instr[S390_MAX_INSTR_SIZE];
611 disassemble_info info;
612 int regidx, instrlen;
613
614 info.read_memory_func = dis_asm_read_memory;
615 instrlen = s390_readinstruction (instr, pc, &info);
616 if (instrlen < 0)
617 return -1;
618 /* check for BR */
619 if (instrlen != 2 || instr[0] != 07 || (instr[1] >> 4) != 0xf)
620 return 0;
621 regidx = instr[1] & 0xf;
622 /* Check for LMG or LG */
623 instrlen =
624 s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 6 : 4), &info);
625 if (instrlen < 0)
626 return -1;
627 if (GDB_TARGET_IS_ESAME)
628 {
629
630 if (instrlen != 6 || instr[0] != 0xeb || instr[5] != 0x4)
631 return 0;
632 }
633 else if (instrlen != 4 || instr[0] != 0x98)
634 {
635 return 0;
636 }
637 if ((instr[2] >> 4) != 0xf)
638 return 0;
639 if (regidx == 14)
640 return 1;
641 instrlen = s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 12 : 8),
642 &info);
643 if (instrlen < 0)
644 return -1;
645 if (GDB_TARGET_IS_ESAME)
646 {
647 /* Check for LG */
648 if (instrlen != 6 || instr[0] != 0xe3 || instr[5] != 0x4)
649 return 0;
650 }
651 else
652 {
653 /* Check for L */
654 if (instrlen != 4 || instr[0] != 0x58)
655 return 0;
656 }
657 if (instr[2] >> 4 != 0xf)
658 return 0;
659 if (instr[1] >> 4 != regidx)
660 return 0;
661 return 1;
662}
663
664static CORE_ADDR
665s390_sniff_pc_function_start (CORE_ADDR pc, struct frame_info *fi)
666{
667 CORE_ADDR function_start, test_function_start;
668 int loop_cnt, err, function_end;
669 struct frame_extra_info fextra_info;
670 function_start = get_pc_function_start (pc);
671
672 if (function_start == 0)
673 {
674 test_function_start = pc;
675 if (test_function_start & 1)
676 return 0; /* This has to be bogus */
677 loop_cnt = 0;
678 do
679 {
680
681 err =
682 s390_get_frame_info (test_function_start, &fextra_info, fi, 1);
683 loop_cnt++;
684 test_function_start -= 2;
685 function_end = s390_check_function_end (test_function_start);
686 }
687 while (!(function_end == 1 || err || loop_cnt >= 4096 ||
688 (fextra_info.good_prologue)));
689 if (fextra_info.good_prologue)
690 function_start = fextra_info.function_start;
691 else if (function_end == 1)
692 function_start = test_function_start;
693 }
694 return function_start;
695}
696
697
698
699CORE_ADDR
700s390_function_start (struct frame_info *fi)
701{
702 CORE_ADDR function_start = 0;
703
704 if (fi->extra_info && fi->extra_info->initialised)
705 function_start = fi->extra_info->function_start;
706 else if (fi->pc)
707 function_start = get_pc_function_start (fi->pc);
708 return function_start;
709}
710
711
712
713
714int
715s390_frameless_function_invocation (struct frame_info *fi)
716{
717 struct frame_extra_info fextra_info, *fextra_info_ptr;
718 int frameless = 0;
719
720 if (fi->next == NULL) /* no may be frameless */
721 {
722 if (fi->extra_info)
723 fextra_info_ptr = fi->extra_info;
724 else
725 {
726 fextra_info_ptr = &fextra_info;
727 s390_get_frame_info (s390_sniff_pc_function_start (fi->pc, fi),
728 fextra_info_ptr, fi, 1);
729 }
730 frameless = ((fextra_info_ptr->stack_bought == 0));
731 }
732 return frameless;
733
734}
735
736
737static int
738s390_is_sigreturn (CORE_ADDR pc, struct frame_info *sighandler_fi,
739 CORE_ADDR *sregs, CORE_ADDR *sigcaller_pc)
740{
741 bfd_byte instr[S390_MAX_INSTR_SIZE];
742 disassemble_info info;
743 int instrlen;
744 CORE_ADDR scontext;
745 int retval = 0;
746 CORE_ADDR orig_sp;
747 CORE_ADDR temp_sregs;
748
749 scontext = temp_sregs = 0;
750
751 info.read_memory_func = dis_asm_read_memory;
752 instrlen = s390_readinstruction (instr, pc, &info);
753 if (sigcaller_pc)
754 *sigcaller_pc = 0;
755 if (((instrlen == S390_SYSCALL_SIZE) &&
756 (instr[0] == S390_SYSCALL_OPCODE)) &&
757 ((instr[1] == s390_NR_sigreturn) || (instr[1] == s390_NR_rt_sigreturn)))
758 {
759 if (sighandler_fi)
760 {
761 if (s390_frameless_function_invocation (sighandler_fi))
762 orig_sp = sighandler_fi->frame;
763 else
764 orig_sp = ADDR_BITS_REMOVE ((CORE_ADDR)
765 read_memory_integer (sighandler_fi->
766 frame,
767 S390_GPR_SIZE));
768 if (orig_sp && sigcaller_pc)
769 {
770 scontext = orig_sp + S390_SIGNAL_FRAMESIZE;
771 if (pc == scontext && instr[1] == s390_NR_rt_sigreturn)
772 {
773 /* We got a new style rt_signal */
774 /* get address of read ucontext->uc_mcontext */
775 temp_sregs = orig_sp + (GDB_TARGET_IS_ESAME ?
776 S390X_UC_MCONTEXT_OFFSET :
777 S390_UC_MCONTEXT_OFFSET);
778 }
779 else
780 {
781 /* read sigcontext->sregs */
782 temp_sregs = ADDR_BITS_REMOVE ((CORE_ADDR)
783 read_memory_integer (scontext
784 +
785 (GDB_TARGET_IS_ESAME
786 ?
787 S390X_SIGCONTEXT_SREGS_OFFSET
788 :
789 S390_SIGCONTEXT_SREGS_OFFSET),
790 S390_GPR_SIZE));
791
792 }
793 /* read sigregs->psw.addr */
794 *sigcaller_pc =
795 ADDR_BITS_REMOVE ((CORE_ADDR)
796 read_memory_integer (temp_sregs +
797 REGISTER_BYTE
798 (S390_PC_REGNUM),
799 S390_PSW_ADDR_SIZE));
800 }
801 }
802 retval = 1;
803 }
804 if (sregs)
805 *sregs = temp_sregs;
806 return retval;
807}
808
809/*
810 We need to do something better here but this will keep us out of trouble
811 for the moment.
812 For some reason the blockframe.c calls us with fi->next->fromleaf
813 so this seems of little use to us. */
814void
815s390_init_frame_pc_first (int next_fromleaf, struct frame_info *fi)
816{
817 CORE_ADDR sigcaller_pc;
818
819 fi->pc = 0;
820 if (next_fromleaf)
821 {
822 fi->pc = ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
823 /* fix signal handlers */
824 }
825 else if (fi->next && fi->next->pc)
826 fi->pc = s390_frame_saved_pc_nofix (fi->next);
827 if (fi->pc && fi->next && fi->next->frame &&
828 s390_is_sigreturn (fi->pc, fi->next, NULL, &sigcaller_pc))
829 {
830 fi->pc = sigcaller_pc;
831 }
832
833}
834
835void
836s390_init_extra_frame_info (int fromleaf, struct frame_info *fi)
837{
838 fi->extra_info = frame_obstack_alloc (sizeof (struct frame_extra_info));
839 if (fi->pc)
840 s390_get_frame_info (s390_sniff_pc_function_start (fi->pc, fi),
841 fi->extra_info, fi, 1);
842 else
843 s390_memset_extra_info (fi->extra_info);
844}
845
846/* If saved registers of frame FI are not known yet, read and cache them.
847 &FEXTRA_INFOP contains struct frame_extra_info; TDATAP can be NULL,
848 in which case the framedata are read. */
849
850void
851s390_frame_init_saved_regs (struct frame_info *fi)
852{
853
854 int quick;
855
856 if (fi->saved_regs == NULL)
857 {
858 /* zalloc memsets the saved regs */
859 frame_saved_regs_zalloc (fi);
860 if (fi->pc)
861 {
862 quick = (fi->extra_info && fi->extra_info->initialised
863 && fi->extra_info->good_prologue);
864 s390_get_frame_info (quick ? fi->extra_info->function_start :
865 s390_sniff_pc_function_start (fi->pc, fi),
866 fi->extra_info, fi, !quick);
867 }
868 }
869}
870
871
872
873CORE_ADDR
874s390_frame_args_address (struct frame_info *fi)
875{
876
877 /* Apparently gdb already knows gdb_args_offset itself */
878 return fi->frame;
879}
880
881
882static CORE_ADDR
883s390_frame_saved_pc_nofix (struct frame_info *fi)
884{
885 if (fi->extra_info && fi->extra_info->saved_pc_valid)
886 return fi->extra_info->saved_pc;
887 s390_frame_init_saved_regs (fi);
888 if (fi->extra_info)
889 {
890 fi->extra_info->saved_pc_valid = 1;
891 if (fi->extra_info->good_prologue)
892 {
893 if (fi->saved_regs[S390_RETADDR_REGNUM])
894 {
895 return (fi->extra_info->saved_pc =
896 ADDR_BITS_REMOVE (read_memory_integer
897 (fi->saved_regs[S390_RETADDR_REGNUM],
898 S390_GPR_SIZE)));
899 }
900 }
901 }
902 return 0;
903}
904
905CORE_ADDR
906s390_frame_saved_pc (struct frame_info *fi)
907{
908 CORE_ADDR saved_pc = 0, sig_pc;
909
910 if (fi->extra_info && fi->extra_info->sig_fixed_saved_pc_valid)
911 return fi->extra_info->sig_fixed_saved_pc;
912 saved_pc = s390_frame_saved_pc_nofix (fi);
913
914 if (fi->extra_info)
915 {
916 fi->extra_info->sig_fixed_saved_pc_valid = 1;
917 if (saved_pc)
918 {
919 if (s390_is_sigreturn (saved_pc, fi, NULL, &sig_pc))
920 saved_pc = sig_pc;
921 }
922 fi->extra_info->sig_fixed_saved_pc = saved_pc;
923 }
924 return saved_pc;
925}
926
927
928
929
930/* We want backtraces out of signal handlers so we don't
931 set thisframe->signal_handler_caller to 1 */
932
933CORE_ADDR
934s390_frame_chain (struct frame_info *thisframe)
935{
936 CORE_ADDR prev_fp = 0;
937
938 if (thisframe->prev && thisframe->prev->frame)
939 prev_fp = thisframe->prev->frame;
940 else
941 {
942 int sigreturn = 0;
943 CORE_ADDR sregs = 0;
944 struct frame_extra_info prev_fextra_info;
945
946 memset (&prev_fextra_info, 0, sizeof (prev_fextra_info));
947 if (thisframe->pc)
948 {
949 CORE_ADDR saved_pc, sig_pc;
950
951 saved_pc = s390_frame_saved_pc_nofix (thisframe);
952 if (saved_pc)
953 {
954 if ((sigreturn =
955 s390_is_sigreturn (saved_pc, thisframe, &sregs, &sig_pc)))
956 saved_pc = sig_pc;
957 s390_get_frame_info (s390_sniff_pc_function_start
958 (saved_pc, NULL), &prev_fextra_info, NULL,
959 1);
960 }
961 }
962 if (sigreturn)
963 {
964 /* read sigregs,regs.gprs[11 or 15] */
965 prev_fp = read_memory_integer (sregs +
966 REGISTER_BYTE (S390_GP0_REGNUM +
967 (prev_fextra_info.
968 frame_pointer_saved_pc
969 ? 11 : 15)),
970 S390_GPR_SIZE);
971 thisframe->extra_info->sigcontext = sregs;
972 }
973 else
974 {
975 if (thisframe->saved_regs)
976 {
977
978 int regno;
979
980 regno =
981 ((prev_fextra_info.frame_pointer_saved_pc
982 && thisframe->
983 saved_regs[S390_FRAME_REGNUM]) ? S390_FRAME_REGNUM :
984 S390_SP_REGNUM);
985 if (thisframe->saved_regs[regno])
986 prev_fp =
987 read_memory_integer (thisframe->saved_regs[regno],
988 S390_GPR_SIZE);
989 }
990 }
991 }
992 return ADDR_BITS_REMOVE (prev_fp);
993}
994
995/*
996 Whether struct frame_extra_info is actually needed I'll have to figure
997 out as our frames are similar to rs6000 there is a possibility
998 i386 dosen't need it. */
999
1000
1001
1002/* a given return value in `regbuf' with a type `valtype', extract and copy its
1003 value into `valbuf' */
1004void
1005s390_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
1006{
1007 /* floats and doubles are returned in fpr0. fpr's have a size of 8 bytes.
1008 We need to truncate the return value into float size (4 byte) if
1009 necessary. */
1010 int len = TYPE_LENGTH (valtype);
1011
1012 if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
f2c6cfba 1013 memcpy (valbuf, &regbuf[REGISTER_BYTE (S390_FP0_REGNUM)], len);
5769d3cd
AC		 1014 else
1015 {
1016 int offset = 0;
1017 /* return value is copied starting from r2. */
1018 if (TYPE_LENGTH (valtype) < S390_GPR_SIZE)
1019 offset = S390_GPR_SIZE - TYPE_LENGTH (valtype);
1020 memcpy (valbuf,
1021 regbuf + REGISTER_BYTE (S390_GP0_REGNUM + 2) + offset,
1022 TYPE_LENGTH (valtype));
1023 }
1024}
1025
1026
1027static char *
1028s390_promote_integer_argument (struct type *valtype, char *valbuf,
1029 char *reg_buff, int *arglen)
1030{
1031 char *value = valbuf;
1032 int len = TYPE_LENGTH (valtype);
1033
1034 if (len < S390_GPR_SIZE)
1035 {
1036 /* We need to upgrade this value to a register to pass it correctly */
1037 int idx, diff = S390_GPR_SIZE - len, negative =
1038 (!TYPE_UNSIGNED (valtype) && value[0] & 0x80);
1039 for (idx = 0; idx < S390_GPR_SIZE; idx++)
1040 {
1041 reg_buff[idx] = (idx < diff ? (negative ? 0xff : 0x0) :
1042 value[idx - diff]);
1043 }
1044 value = reg_buff;
1045 *arglen = S390_GPR_SIZE;
1046 }
1047 else
1048 {
1049 if (len & (S390_GPR_SIZE - 1))
1050 {
1051 fprintf_unfiltered (gdb_stderr,
1052 "s390_promote_integer_argument detected an argument not "
1053 "a multiple of S390_GPR_SIZE & greater than S390_GPR_SIZE "
1054 "we might not deal with this correctly.\n");
1055 }
1056 *arglen = len;
1057 }
1058
1059 return (value);
1060}
1061
1062void
1063s390_store_return_value (struct type *valtype, char *valbuf)
1064{
1065 int arglen;
1066 char *reg_buff = alloca (max (S390_FPR_SIZE, REGISTER_SIZE)), *value;
1067
1068 if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
1069 {
1070 DOUBLEST tempfloat = extract_floating (valbuf, TYPE_LENGTH (valtype));
1071
1072 floatformat_from_doublest (&floatformat_ieee_double_big, &tempfloat,
1073 reg_buff);
1074 write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM), reg_buff,
1075 S390_FPR_SIZE);
1076 }
1077 else
1078 {
1079 value =
1080 s390_promote_integer_argument (valtype, valbuf, reg_buff, &arglen);
1081 /* Everything else is returned in GPR2 and up. */
1082 write_register_bytes (REGISTER_BYTE (S390_GP0_REGNUM + 2), value,
1083 arglen);
1084 }
1085}
1086static int
1087gdb_print_insn_s390 (bfd_vma memaddr, disassemble_info * info)
1088{
1089 bfd_byte instrbuff[S390_MAX_INSTR_SIZE];
1090 int instrlen, cnt;
1091
1092 instrlen = s390_readinstruction (instrbuff, (CORE_ADDR) memaddr, info);
1093 if (instrlen < 0)
1094 {
1095 (*info->memory_error_func) (instrlen, memaddr, info);
1096 return -1;
1097 }
1098 for (cnt = 0; cnt < instrlen; cnt++)
1099 info->fprintf_func (info->stream, "%02X ", instrbuff[cnt]);
1100 for (cnt = instrlen; cnt < S390_MAX_INSTR_SIZE; cnt++)
1101 info->fprintf_func (info->stream, " ");
1102 instrlen = print_insn_s390 (memaddr, info);
1103 return instrlen;
1104}
1105
1106
1107
1108/* Not the most efficent code in the world */
1109int
1110s390_fp_regnum ()
1111{
1112 int regno = S390_SP_REGNUM;
1113 struct frame_extra_info fextra_info;
1114
1115 CORE_ADDR pc = ADDR_BITS_REMOVE (read_register (S390_PC_REGNUM));
1116
1117 s390_get_frame_info (s390_sniff_pc_function_start (pc, NULL), &fextra_info,
1118 NULL, 1);
1119 if (fextra_info.frame_pointer_saved_pc)
1120 regno = S390_FRAME_REGNUM;
1121 return regno;
1122}
1123
1124CORE_ADDR
1125s390_read_fp ()
1126{
1127 return read_register (s390_fp_regnum ());
1128}
1129
1130
1131void
1132s390_write_fp (CORE_ADDR val)
1133{
1134 write_register (s390_fp_regnum (), val);
1135}
1136
1137
4c8287ac
JB		 1138static void
1139s390_pop_frame_regular (struct frame_info *frame)
5769d3cd 1140{
4c8287ac
JB		 1141 int regnum;
1142
1143 write_register (S390_PC_REGNUM, FRAME_SAVED_PC (frame));
1144
1145 /* Restore any saved registers. */
1146 for (regnum = 0; regnum < NUM_REGS; regnum++)
1147 if (frame->saved_regs[regnum] != 0)
1148 {
1149 ULONGEST value;
1150
1151 value = read_memory_unsigned_integer (frame->saved_regs[regnum],
1152 REGISTER_RAW_SIZE (regnum));
1153 write_register (regnum, value);
1154 }
5769d3cd 1155
9a1befc9
JB		 1156 /* Actually cut back the stack. Remember that the SP's element of
1157 saved_regs is the old SP itself, not the address at which it is
1158 saved. */
1159 write_register (S390_SP_REGNUM, frame->saved_regs[S390_SP_REGNUM]);
5769d3cd 1160
4c8287ac
JB		 1161 /* Throw away any cached frame information. */
1162 flush_cached_frames ();
5769d3cd
AC		 1163}
1164
4c8287ac
JB		 1165
1166/* Destroy the innermost (Top-Of-Stack) stack frame, restoring the
1167 machine state that was in effect before the frame was created.
1168 Used in the contexts of the "return" command, and of
1169 target function calls from the debugger. */
1170void
1171s390_pop_frame ()
1172{
1173 /* This function checks for and handles generic dummy frames, and
1174 calls back to our function for ordinary frames. */
1175 generic_pop_current_frame (s390_pop_frame_regular);
1176}
1177
1178
78f8b424
JB		 1179/* Return non-zero if TYPE is an integer-like type, zero otherwise.
1180 "Integer-like" types are those that should be passed the way
1181 integers are: integers, enums, ranges, characters, and booleans. */
1182static int
1183is_integer_like (struct type *type)
1184{
1185 enum type_code code = TYPE_CODE (type);
1186
1187 return (code == TYPE_CODE_INT
1188 || code == TYPE_CODE_ENUM
1189 || code == TYPE_CODE_RANGE
1190 || code == TYPE_CODE_CHAR
1191 || code == TYPE_CODE_BOOL);
1192}
1193
1194
1195/* Return non-zero if TYPE is a pointer-like type, zero otherwise.
1196 "Pointer-like" types are those that should be passed the way
1197 pointers are: pointers and references. */
1198static int
1199is_pointer_like (struct type *type)
1200{
1201 enum type_code code = TYPE_CODE (type);
1202
1203 return (code == TYPE_CODE_PTR
1204 || code == TYPE_CODE_REF);
1205}
1206
1207
20a940cc
JB		 1208/* Return non-zero if TYPE is a `float singleton' or `double
1209 singleton', zero otherwise.
1210
1211 A `T singleton' is a struct type with one member, whose type is
1212 either T or a `T singleton'. So, the following are all float
1213 singletons:
1214
1215 struct { float x };
1216 struct { struct { float x; } x; };
1217 struct { struct { struct { float x; } x; } x; };
1218
1219 ... and so on.
1220
1221 WHY THE HECK DO WE CARE ABOUT THIS??? Well, it turns out that GCC
1222 passes all float singletons and double singletons as if they were
1223 simply floats or doubles. This is *not* what the ABI says it
1224 should do. */
1225static int
1226is_float_singleton (struct type *type)
1227{
1228 return (TYPE_CODE (type) == TYPE_CODE_STRUCT
1229 && TYPE_NFIELDS (type) == 1
1230 && (TYPE_CODE (TYPE_FIELD_TYPE (type, 0)) == TYPE_CODE_FLT
1231 || is_float_singleton (TYPE_FIELD_TYPE (type, 0))));
1232}
1233
1234
1235/* Return non-zero if TYPE is a struct-like type, zero otherwise.
1236 "Struct-like" types are those that should be passed as structs are:
1237 structs and unions.
1238
1239 As an odd quirk, not mentioned in the ABI, GCC passes float and
1240 double singletons as if they were a plain float, double, etc. (The
1241 corresponding union types are handled normally.) So we exclude
1242 those types here. *shrug* */
1243static int
1244is_struct_like (struct type *type)
1245{
1246 enum type_code code = TYPE_CODE (type);
1247
1248 return (code == TYPE_CODE_UNION
1249 || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type)));
1250}
1251
1252
1253/* Return non-zero if TYPE is a float-like type, zero otherwise.
1254 "Float-like" types are those that should be passed as
1255 floating-point values are.
1256
1257 You'd think this would just be floats, doubles, long doubles, etc.
1258 But as an odd quirk, not mentioned in the ABI, GCC passes float and
1259 double singletons as if they were a plain float, double, etc. (The
1260 corresponding union types are handled normally.) So we exclude
1261 those types here. *shrug* */
1262static int
1263is_float_like (struct type *type)
1264{
1265 return (TYPE_CODE (type) == TYPE_CODE_FLT
1266 || is_float_singleton (type));
1267}
1268
1269
78f8b424
JB		 1270/* Return non-zero if TYPE is considered a `DOUBLE_OR_FLOAT', as
1271 defined by the parameter passing conventions described in the
1272 "Linux for S/390 ELF Application Binary Interface Supplement".
1273 Otherwise, return zero. */
1274static int
1275is_double_or_float (struct type *type)
1276{
20a940cc 1277 return (is_float_like (type)
78f8b424
JB		 1278 && (TYPE_LENGTH (type) == 4
1279 || TYPE_LENGTH (type) == 8));
1280}
1281
5769d3cd 1282
78f8b424
JB		 1283/* Return non-zero if TYPE is considered a `SIMPLE_ARG', as defined by
1284 the parameter passing conventions described in the "Linux for S/390
1285 ELF Application Binary Interface Supplement". Return zero otherwise. */
1286static int
1287is_simple_arg (struct type *type)
1288{
78f8b424
JB		 1289 unsigned length = TYPE_LENGTH (type);
1290
a1677dfb
JB		 1291 /* This is almost a direct translation of the ABI's language, except
1292 that we have to exclude 8-byte structs; those are DOUBLE_ARGs. */
78f8b424
JB		 1293 return ((is_integer_like (type) && length <= 4)
1294 || is_pointer_like (type)
20a940cc
JB		 1295 || (is_struct_like (type) && length != 8)
1296 || (is_float_like (type) && length == 16));
78f8b424
JB		 1297}
1298
1299
1300/* Return non-zero if TYPE should be passed as a pointer to a copy,
1301 zero otherwise. TYPE must be a SIMPLE_ARG, as recognized by
1302 `is_simple_arg'. */
1303static int
1304pass_by_copy_ref (struct type *type)
1305{
78f8b424
JB		 1306 unsigned length = TYPE_LENGTH (type);
1307
20a940cc
JB		 1308 return ((is_struct_like (type) && length != 1 && length != 2 && length != 4)
1309 || (is_float_like (type) && length == 16));
78f8b424
JB		 1310}
1311
1312
1313/* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full
1314 word as required for the ABI. */
1315static LONGEST
1316extend_simple_arg (struct value *arg)
1317{
1318 struct type *type = VALUE_TYPE (arg);
1319
1320 /* Even structs get passed in the least significant bits of the
1321 register / memory word. It's not really right to extract them as
1322 an integer, but it does take care of the extension. */
1323 if (TYPE_UNSIGNED (type))
1324 return extract_unsigned_integer (VALUE_CONTENTS (arg),
1325 TYPE_LENGTH (type));
1326 else
1327 return extract_signed_integer (VALUE_CONTENTS (arg),
1328 TYPE_LENGTH (type));
1329}
1330
1331
1332/* Return non-zero if TYPE is a `DOUBLE_ARG', as defined by the
1333 parameter passing conventions described in the "Linux for S/390 ELF
1334 Application Binary Interface Supplement". Return zero otherwise. */
1335static int
1336is_double_arg (struct type *type)
1337{
78f8b424
JB		 1338 unsigned length = TYPE_LENGTH (type);
1339
1340 return ((is_integer_like (type)
20a940cc 1341 || is_struct_like (type))
78f8b424
JB		 1342 && length == 8);
1343}
1344
1345
1346/* Round ADDR up to the next N-byte boundary. N must be a power of
1347 two. */
1348static CORE_ADDR
1349round_up (CORE_ADDR addr, int n)
1350{
1351 /* Check that N is really a power of two. */
1352 gdb_assert (n && (n & (n-1)) == 0);
1353 return ((addr + n - 1) & -n);
1354}
1355
1356
1357/* Round ADDR down to the next N-byte boundary. N must be a power of
1358 two. */
1359static CORE_ADDR
1360round_down (CORE_ADDR addr, int n)
1361{
1362 /* Check that N is really a power of two. */
1363 gdb_assert (n && (n & (n-1)) == 0);
1364 return (addr & -n);
1365}
1366
1367
1368/* Return the alignment required by TYPE. */
1369static int
1370alignment_of (struct type *type)
1371{
1372 int alignment;
1373
1374 if (is_integer_like (type)
1375 || is_pointer_like (type)
1376 || TYPE_CODE (type) == TYPE_CODE_FLT)
1377 alignment = TYPE_LENGTH (type);
1378 else if (TYPE_CODE (type) == TYPE_CODE_STRUCT
1379 || TYPE_CODE (type) == TYPE_CODE_UNION)
1380 {
1381 int i;
1382
1383 alignment = 1;
1384 for (i = 0; i < TYPE_NFIELDS (type); i++)
1385 {
1386 int field_alignment = alignment_of (TYPE_FIELD_TYPE (type, i));
1387
1388 if (field_alignment > alignment)
1389 alignment = field_alignment;
1390 }
1391 }
1392 else
1393 alignment = 1;
1394
1395 /* Check that everything we ever return is a power of two. Lots of
1396 code doesn't want to deal with aligning things to arbitrary
1397 boundaries. */
1398 gdb_assert ((alignment & (alignment - 1)) == 0);
1399
1400 return alignment;
1401}
1402
1403
1404/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in
1405 place to be passed to a function, as specified by the "Linux for
1406 S/390 ELF Application Binary Interface Supplement".
1407
1408 SP is the current stack pointer. We must put arguments, links,
1409 padding, etc. whereever they belong, and return the new stack
1410 pointer value.
1411
1412 If STRUCT_RETURN is non-zero, then the function we're calling is
1413 going to return a structure by value; STRUCT_ADDR is the address of
1414 a block we've allocated for it on the stack.
1415
1416 Our caller has taken care of any type promotions needed to satisfy
1417 prototypes or the old K&R argument-passing rules. */
5769d3cd 1418CORE_ADDR
d45fc520 1419s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
5769d3cd
AC		 1420 int struct_return, CORE_ADDR struct_addr)
1421{
78f8b424
JB		 1422 int i;
1423 int pointer_size = (TARGET_PTR_BIT / TARGET_CHAR_BIT);
5769d3cd 1424
78f8b424
JB		 1425 /* The number of arguments passed by reference-to-copy. */
1426 int num_copies;
5769d3cd 1427
78f8b424
JB		 1428 /* If the i'th argument is passed as a reference to a copy, then
1429 copy_addr[i] is the address of the copy we made. */
1430 CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
5769d3cd 1431
78f8b424
JB		 1432 /* Build the reference-to-copy area. */
1433 num_copies = 0;
1434 for (i = 0; i < nargs; i++)
1435 {
1436 struct value *arg = args[i];
1437 struct type *type = VALUE_TYPE (arg);
1438 unsigned length = TYPE_LENGTH (type);
5769d3cd 1439
78f8b424
JB		 1440 if (is_simple_arg (type)
1441 && pass_by_copy_ref (type))
01c464e9 1442 {
78f8b424
JB		 1443 sp -= length;
1444 sp = round_down (sp, alignment_of (type));
1445 write_memory (sp, VALUE_CONTENTS (arg), length);
1446 copy_addr[i] = sp;
1447 num_copies++;
01c464e9 1448 }
5769d3cd 1449 }
5769d3cd 1450
78f8b424
JB		 1451 /* Reserve space for the parameter area. As a conservative
1452 simplification, we assume that everything will be passed on the
1453 stack. */
1454 {
1455 int i;
1456
1457 for (i = 0; i < nargs; i++)
1458 {
1459 struct value *arg = args[i];
1460 struct type *type = VALUE_TYPE (arg);
1461 int length = TYPE_LENGTH (type);
1462
1463 sp = round_down (sp, alignment_of (type));
1464
1465 /* SIMPLE_ARG values get extended to 32 bits. Assume every
1466 argument is. */
1467 if (length < 4) length = 4;
1468 sp -= length;
1469 }
1470 }
1471
1472 /* Include space for any reference-to-copy pointers. */
1473 sp = round_down (sp, pointer_size);
1474 sp -= num_copies * pointer_size;
1475
1476 /* After all that, make sure it's still aligned on an eight-byte
1477 boundary. */
1478 sp = round_down (sp, 8);
1479
1480 /* Finally, place the actual parameters, working from SP towards
1481 higher addresses. The code above is supposed to reserve enough
1482 space for this. */
1483 {
1484 int fr = 0;
1485 int gr = 2;
1486 CORE_ADDR starg = sp;
1487
1488 for (i = 0; i < nargs; i++)
1489 {
1490 struct value *arg = args[i];
1491 struct type *type = VALUE_TYPE (arg);
1492
1493 if (is_double_or_float (type)
1494 && fr <= 2)
1495 {
1496 /* When we store a single-precision value in an FP register,
1497 it occupies the leftmost bits. */
1498 write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM + fr),
1499 VALUE_CONTENTS (arg),
1500 TYPE_LENGTH (type));
1501 fr += 2;
1502 }
1503 else if (is_simple_arg (type)
1504 && gr <= 6)
1505 {
1506 /* Do we need to pass a pointer to our copy of this
1507 argument? */
1508 if (pass_by_copy_ref (type))
1509 write_register (S390_GP0_REGNUM + gr, copy_addr[i]);
1510 else
1511 write_register (S390_GP0_REGNUM + gr, extend_simple_arg (arg));
1512
1513 gr++;
1514 }
1515 else if (is_double_arg (type)
1516 && gr <= 5)
1517 {
1518 write_register_gen (S390_GP0_REGNUM + gr,
1519 VALUE_CONTENTS (arg));
1520 write_register_gen (S390_GP0_REGNUM + gr + 1,
1521 VALUE_CONTENTS (arg) + 4);
1522 gr += 2;
1523 }
1524 else
1525 {
1526 /* The `OTHER' case. */
1527 enum type_code code = TYPE_CODE (type);
1528 unsigned length = TYPE_LENGTH (type);
1529
1530 /* If we skipped r6 because we couldn't fit a DOUBLE_ARG
1531 in it, then don't go back and use it again later. */
1532 if (is_double_arg (type) && gr == 6)
1533 gr = 7;
1534
1535 if (is_simple_arg (type))
1536 {
1537 /* Simple args are always either extended to 32 bits,
1538 or pointers. */
1539 starg = round_up (starg, 4);
1540
1541 /* Do we need to pass a pointer to our copy of this
1542 argument? */
1543 if (pass_by_copy_ref (type))
1544 write_memory_signed_integer (starg, pointer_size,
1545 copy_addr[i]);
1546 else
1547 /* Simple args are always extended to 32 bits. */
1548 write_memory_signed_integer (starg, 4,
1549 extend_simple_arg (arg));
1550 starg += 4;
1551 }
1552 else
1553 {
20a940cc
JB		 1554 /* You'd think we should say:
1555 starg = round_up (starg, alignment_of (type));
1556 Unfortunately, GCC seems to simply align the stack on
1557 a four-byte boundary, even when passing doubles. */
1558 starg = round_up (starg, 4);
78f8b424
JB		 1559 write_memory (starg, VALUE_CONTENTS (arg), length);
1560 starg += length;
1561 }
1562 }
1563 }
1564 }
1565
1566 /* Allocate the standard frame areas: the register save area, the
1567 word reserved for the compiler (which seems kind of meaningless),
1568 and the back chain pointer. */
1569 sp -= 96;
1570
1571 /* Write the back chain pointer into the first word of the stack
1572 frame. This will help us get backtraces from within functions
1573 called from GDB. */
1574 write_memory_unsigned_integer (sp, (TARGET_PTR_BIT / TARGET_CHAR_BIT),
1575 read_fp ());
1576
1577 return sp;
5769d3cd
AC		 1578}
1579
5769d3cd
AC		 1580/* Return the GDB type object for the "standard" data type
1581 of data in register N. */
1582struct type *
1583s390_register_virtual_type (int regno)
1584{
1585 return ((unsigned) regno - S390_FPC_REGNUM) <
1586 S390_NUM_FPRS ? builtin_type_double : builtin_type_int;
1587}
1588
1589
1590struct type *
1591s390x_register_virtual_type (int regno)
1592{
1593 return (regno == S390_FPC_REGNUM) ||
1594 (regno >= S390_FIRST_ACR && regno <= S390_LAST_ACR) ? builtin_type_int :
1595 (regno >= S390_FP0_REGNUM) ? builtin_type_double : builtin_type_long;
1596}
1597
1598
1599
1600void
1601s390_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
1602{
1603 write_register (S390_GP0_REGNUM + 2, addr);
1604}
1605
1606
1607
1608static unsigned char *
1609s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
1610{
1611 static unsigned char breakpoint[] = { 0x0, 0x1 };
1612
1613 *lenptr = sizeof (breakpoint);
1614 return breakpoint;
1615}
1616
1617/* Advance PC across any function entry prologue instructions to reach some
1618 "real" code. */
1619CORE_ADDR
1620s390_skip_prologue (CORE_ADDR pc)
1621{
1622 struct frame_extra_info fextra_info;
1623
1624 s390_get_frame_info (pc, &fextra_info, NULL, 1);
1625 return fextra_info.skip_prologue_function_start;
1626}
1627
5769d3cd
AC		 1628/* Immediately after a function call, return the saved pc.
1629 Can't go through the frames for this because on some machines
1630 the new frame is not set up until the new function executes
1631 some instructions. */
1632CORE_ADDR
1633s390_saved_pc_after_call (struct frame_info *frame)
1634{
1635 return ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
1636}
1637
1638static CORE_ADDR
1639s390_addr_bits_remove (CORE_ADDR addr)
1640{
1641 return (addr) & 0x7fffffff;
1642}
1643
1644
1645static CORE_ADDR
1646s390_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
1647{
d4d0c21e 1648 write_register (S390_RETADDR_REGNUM, CALL_DUMMY_ADDRESS ());
5769d3cd
AC		 1649 return sp;
1650}
1651
1652struct gdbarch *
1653s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1654{
d4d0c21e 1655 static LONGEST s390_call_dummy_words[] = { 0 };
5769d3cd
AC		 1656 struct gdbarch *gdbarch;
1657 struct gdbarch_tdep *tdep;
1658 int elf_flags;
1659
1660 /* First see if there is already a gdbarch that can satisfy the request. */
1661 arches = gdbarch_list_lookup_by_info (arches, &info);
1662 if (arches != NULL)
1663 return arches->gdbarch;
1664
1665 /* None found: is the request for a s390 architecture? */
1666 if (info.bfd_arch_info->arch != bfd_arch_s390)
1667 return NULL; /* No; then it's not for us. */
1668
1669 /* Yes: create a new gdbarch for the specified machine type. */
1670 gdbarch = gdbarch_alloc (&info, NULL);
1671
1672 set_gdbarch_believe_pcc_promotion (gdbarch, 0);
1673
5769d3cd
AC		 1674 set_gdbarch_frame_args_skip (gdbarch, 0);
1675 set_gdbarch_frame_args_address (gdbarch, s390_frame_args_address);
1676 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1677 set_gdbarch_frame_init_saved_regs (gdbarch, s390_frame_init_saved_regs);
1678 set_gdbarch_frame_locals_address (gdbarch, s390_frame_args_address);
1679 /* We can't do this */
1680 set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
1681 set_gdbarch_store_struct_return (gdbarch, s390_store_struct_return);
1682 set_gdbarch_extract_return_value (gdbarch, s390_extract_return_value);
1683 set_gdbarch_store_return_value (gdbarch, s390_store_return_value);
1684 /* Amount PC must be decremented by after a breakpoint.
1685 This is often the number of bytes in BREAKPOINT
1686 but not always. */
1687 set_gdbarch_decr_pc_after_break (gdbarch, 2);
1688 set_gdbarch_pop_frame (gdbarch, s390_pop_frame);
5769d3cd
AC		 1689 set_gdbarch_ieee_float (gdbarch, 1);
1690 /* Stack grows downward. */
1691 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1692 /* Offset from address of function to start of its code.
1693 Zero on most machines. */
1694 set_gdbarch_function_start_offset (gdbarch, 0);
1695 set_gdbarch_max_register_raw_size (gdbarch, 8);
1696 set_gdbarch_max_register_virtual_size (gdbarch, 8);
1697 set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc);
1698 set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue);
1699 set_gdbarch_init_extra_frame_info (gdbarch, s390_init_extra_frame_info);
1700 set_gdbarch_init_frame_pc_first (gdbarch, s390_init_frame_pc_first);
1701 set_gdbarch_read_fp (gdbarch, s390_read_fp);
1702 set_gdbarch_write_fp (gdbarch, s390_write_fp);
1703 /* This function that tells us whether the function invocation represented
1704 by FI does not have a frame on the stack associated with it. If it
1705 does not, FRAMELESS is set to 1, else 0. */
1706 set_gdbarch_frameless_function_invocation (gdbarch,
1707 s390_frameless_function_invocation);
1708 /* Return saved PC from a frame */
1709 set_gdbarch_frame_saved_pc (gdbarch, s390_frame_saved_pc);
1710 /* FRAME_CHAIN takes a frame's nominal address
1711 and produces the frame's chain-pointer. */
1712 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1713 set_gdbarch_saved_pc_after_call (gdbarch, s390_saved_pc_after_call);
1714 set_gdbarch_register_byte (gdbarch, s390_register_byte);
1715 set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM);
1716 set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM);
1717 set_gdbarch_fp_regnum (gdbarch, S390_FP_REGNUM);
1718 set_gdbarch_fp0_regnum (gdbarch, S390_FP0_REGNUM);
1719 set_gdbarch_num_regs (gdbarch, S390_NUM_REGS);
1720 set_gdbarch_cannot_fetch_register (gdbarch, s390_cannot_fetch_register);
1721 set_gdbarch_cannot_store_register (gdbarch, s390_cannot_fetch_register);
1722 set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
1723 set_gdbarch_use_struct_convention (gdbarch, generic_use_struct_convention);
8001d1e4 1724 set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid);
5769d3cd
AC		 1725 set_gdbarch_register_name (gdbarch, s390_register_name);
1726 set_gdbarch_stab_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1727 set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1728 set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
5769d3cd 1729
d4d0c21e 1730 /* Parameters for inferior function calls. */
5769d3cd 1731 set_gdbarch_call_dummy_p (gdbarch, 1);
d4d0c21e
JB		 1732 set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
1733 set_gdbarch_call_dummy_length (gdbarch, 0);
1734 set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
1735 set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
1736 set_gdbarch_call_dummy_start_offset (gdbarch, 0);
1737 set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_at_entry_point);
1738 set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
1739 set_gdbarch_push_arguments (gdbarch, s390_push_arguments);
1740 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1741 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
5769d3cd
AC		 1742 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1743 set_gdbarch_extract_struct_value_address (gdbarch, 0);
d4d0c21e 1744 set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
5769d3cd 1745 set_gdbarch_push_return_address (gdbarch, s390_push_return_address);
d4d0c21e
JB		 1746 set_gdbarch_sizeof_call_dummy_words (gdbarch,
1747 sizeof (s390_call_dummy_words));
1748 set_gdbarch_call_dummy_words (gdbarch, s390_call_dummy_words);
0adb2aba
JB		 1749 set_gdbarch_coerce_float_to_double (gdbarch,
1750 standard_coerce_float_to_double);
5769d3cd
AC		 1751
1752 switch (info.bfd_arch_info->mach)
1753 {
1754 case bfd_mach_s390_esa:
1755 set_gdbarch_register_size (gdbarch, 4);
5769d3cd
AC		 1756 set_gdbarch_register_raw_size (gdbarch, s390_register_raw_size);
1757 set_gdbarch_register_virtual_size (gdbarch, s390_register_raw_size);
1758 set_gdbarch_register_virtual_type (gdbarch, s390_register_virtual_type);
1759
1760 set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove);
5769d3cd
AC		 1761 set_gdbarch_register_bytes (gdbarch, S390_REGISTER_BYTES);
1762 break;
1763 case bfd_mach_s390_esame:
1764 set_gdbarch_register_size (gdbarch, 8);
5769d3cd
AC		 1765 set_gdbarch_register_raw_size (gdbarch, s390x_register_raw_size);
1766 set_gdbarch_register_virtual_size (gdbarch, s390x_register_raw_size);
1767 set_gdbarch_register_virtual_type (gdbarch,
1768 s390x_register_virtual_type);
1769
1770 set_gdbarch_long_bit (gdbarch, 64);
1771 set_gdbarch_long_long_bit (gdbarch, 64);
1772 set_gdbarch_ptr_bit (gdbarch, 64);
5769d3cd
AC		 1773 set_gdbarch_register_bytes (gdbarch, S390X_REGISTER_BYTES);
1774 break;
1775 }
1776
1777 return gdbarch;
1778}
1779
1780
1781
1782void
1783_initialize_s390_tdep ()
1784{
1785
1786 /* Hook us into the gdbarch mechanism. */
1787 register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init);
1788 if (!tm_print_insn) /* Someone may have already set it */
1789 tm_print_insn = gdb_print_insn_s390;
1790}
1791
1792#endif /* GDBSERVER */
GDB Binutils - Deliverables
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