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2001-11-27 H.J. Lu <hjl@gnu.org>
[deliverable/binutils-gdb.git] / gdb / s390-tdep.c
CommitLineData
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",
152 "gpr0", "gpr1", "gpr2", "gpr3", "gpr4", "gpr5", "gpr6", "gpr7",
153 "gpr8", "gpr9", "gpr10", "gpr11", "gpr12", "gpr13", "gpr14", "gpr15",
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",
159 "fpr0", "fpr1", "fpr2", "fpr3", "fpr4", "fpr5", "fpr6", "fpr7",
160 "fpr8", "fpr9", "fpr10", "fpr11", "fpr12", "fpr13", "fpr14", "fpr15"
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
1138void
1139s390_push_dummy_frame ()
1140{
1141 CORE_ADDR orig_sp = read_register (S390_SP_REGNUM), new_sp;
1142 void *saved_regs = alloca (REGISTER_BYTES);
1143
1144 new_sp = (orig_sp - (REGISTER_BYTES + S390_GPR_SIZE));
1145 read_register_bytes (0, (char *) saved_regs, REGISTER_BYTES);
1146 /* Use saved copy instead of orig_sp as this will have the correct endianness */
1147 write_memory (new_sp, (char *) saved_regs + REGISTER_BYTE (S390_SP_REGNUM),
1148 S390_GPR_SIZE);
1149 write_memory (new_sp + S390_GPR_SIZE, (char *) &saved_regs, REGISTER_BYTES);
1150 write_register (S390_SP_REGNUM, new_sp);
1151}
1152
4c8287ac
JB		 1153
1154static void
1155s390_pop_frame_regular (struct frame_info *frame)
5769d3cd 1156{
4c8287ac
JB		 1157 int regnum;
1158
1159 write_register (S390_PC_REGNUM, FRAME_SAVED_PC (frame));
1160
1161 /* Restore any saved registers. */
1162 for (regnum = 0; regnum < NUM_REGS; regnum++)
1163 if (frame->saved_regs[regnum] != 0)
1164 {
1165 ULONGEST value;
1166
1167 value = read_memory_unsigned_integer (frame->saved_regs[regnum],
1168 REGISTER_RAW_SIZE (regnum));
1169 write_register (regnum, value);
1170 }
5769d3cd 1171
9a1befc9
JB		 1172 /* Actually cut back the stack. Remember that the SP's element of
1173 saved_regs is the old SP itself, not the address at which it is
1174 saved. */
1175 write_register (S390_SP_REGNUM, frame->saved_regs[S390_SP_REGNUM]);
5769d3cd 1176
4c8287ac
JB		 1177 /* Throw away any cached frame information. */
1178 flush_cached_frames ();
5769d3cd
AC		 1179}
1180
4c8287ac
JB		 1181
1182/* Destroy the innermost (Top-Of-Stack) stack frame, restoring the
1183 machine state that was in effect before the frame was created.
1184 Used in the contexts of the "return" command, and of
1185 target function calls from the debugger. */
1186void
1187s390_pop_frame ()
1188{
1189 /* This function checks for and handles generic dummy frames, and
1190 calls back to our function for ordinary frames. */
1191 generic_pop_current_frame (s390_pop_frame_regular);
1192}
1193
1194
78f8b424
JB		 1195/* Return non-zero if TYPE is an integer-like type, zero otherwise.
1196 "Integer-like" types are those that should be passed the way
1197 integers are: integers, enums, ranges, characters, and booleans. */
1198static int
1199is_integer_like (struct type *type)
1200{
1201 enum type_code code = TYPE_CODE (type);
1202
1203 return (code == TYPE_CODE_INT
1204 || code == TYPE_CODE_ENUM
1205 || code == TYPE_CODE_RANGE
1206 || code == TYPE_CODE_CHAR
1207 || code == TYPE_CODE_BOOL);
1208}
1209
1210
1211/* Return non-zero if TYPE is a pointer-like type, zero otherwise.
1212 "Pointer-like" types are those that should be passed the way
1213 pointers are: pointers and references. */
1214static int
1215is_pointer_like (struct type *type)
1216{
1217 enum type_code code = TYPE_CODE (type);
1218
1219 return (code == TYPE_CODE_PTR
1220 || code == TYPE_CODE_REF);
1221}
1222
1223
20a940cc
JB		 1224/* Return non-zero if TYPE is a `float singleton' or `double
1225 singleton', zero otherwise.
1226
1227 A `T singleton' is a struct type with one member, whose type is
1228 either T or a `T singleton'. So, the following are all float
1229 singletons:
1230
1231 struct { float x };
1232 struct { struct { float x; } x; };
1233 struct { struct { struct { float x; } x; } x; };
1234
1235 ... and so on.
1236
1237 WHY THE HECK DO WE CARE ABOUT THIS??? Well, it turns out that GCC
1238 passes all float singletons and double singletons as if they were
1239 simply floats or doubles. This is *not* what the ABI says it
1240 should do. */
1241static int
1242is_float_singleton (struct type *type)
1243{
1244 return (TYPE_CODE (type) == TYPE_CODE_STRUCT
1245 && TYPE_NFIELDS (type) == 1
1246 && (TYPE_CODE (TYPE_FIELD_TYPE (type, 0)) == TYPE_CODE_FLT
1247 || is_float_singleton (TYPE_FIELD_TYPE (type, 0))));
1248}
1249
1250
1251/* Return non-zero if TYPE is a struct-like type, zero otherwise.
1252 "Struct-like" types are those that should be passed as structs are:
1253 structs and unions.
1254
1255 As an odd quirk, not mentioned in the ABI, GCC passes float and
1256 double singletons as if they were a plain float, double, etc. (The
1257 corresponding union types are handled normally.) So we exclude
1258 those types here. *shrug* */
1259static int
1260is_struct_like (struct type *type)
1261{
1262 enum type_code code = TYPE_CODE (type);
1263
1264 return (code == TYPE_CODE_UNION
1265 || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type)));
1266}
1267
1268
1269/* Return non-zero if TYPE is a float-like type, zero otherwise.
1270 "Float-like" types are those that should be passed as
1271 floating-point values are.
1272
1273 You'd think this would just be floats, doubles, long doubles, etc.
1274 But as an odd quirk, not mentioned in the ABI, GCC passes float and
1275 double singletons as if they were a plain float, double, etc. (The
1276 corresponding union types are handled normally.) So we exclude
1277 those types here. *shrug* */
1278static int
1279is_float_like (struct type *type)
1280{
1281 return (TYPE_CODE (type) == TYPE_CODE_FLT
1282 || is_float_singleton (type));
1283}
1284
1285
78f8b424
JB		 1286/* Return non-zero if TYPE is considered a `DOUBLE_OR_FLOAT', as
1287 defined by the parameter passing conventions described in the
1288 "Linux for S/390 ELF Application Binary Interface Supplement".
1289 Otherwise, return zero. */
1290static int
1291is_double_or_float (struct type *type)
1292{
20a940cc 1293 return (is_float_like (type)
78f8b424
JB		 1294 && (TYPE_LENGTH (type) == 4
1295 || TYPE_LENGTH (type) == 8));
1296}
1297
5769d3cd 1298
78f8b424
JB		 1299/* Return non-zero if TYPE is considered a `SIMPLE_ARG', as defined by
1300 the parameter passing conventions described in the "Linux for S/390
1301 ELF Application Binary Interface Supplement". Return zero otherwise. */
1302static int
1303is_simple_arg (struct type *type)
1304{
78f8b424
JB		 1305 unsigned length = TYPE_LENGTH (type);
1306
a1677dfb
JB		 1307 /* This is almost a direct translation of the ABI's language, except
1308 that we have to exclude 8-byte structs; those are DOUBLE_ARGs. */
78f8b424
JB		 1309 return ((is_integer_like (type) && length <= 4)
1310 || is_pointer_like (type)
20a940cc
JB		 1311 || (is_struct_like (type) && length != 8)
1312 || (is_float_like (type) && length == 16));
78f8b424
JB		 1313}
1314
1315
1316/* Return non-zero if TYPE should be passed as a pointer to a copy,
1317 zero otherwise. TYPE must be a SIMPLE_ARG, as recognized by
1318 `is_simple_arg'. */
1319static int
1320pass_by_copy_ref (struct type *type)
1321{
78f8b424
JB		 1322 unsigned length = TYPE_LENGTH (type);
1323
20a940cc
JB		 1324 return ((is_struct_like (type) && length != 1 && length != 2 && length != 4)
1325 || (is_float_like (type) && length == 16));
78f8b424
JB		 1326}
1327
1328
1329/* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full
1330 word as required for the ABI. */
1331static LONGEST
1332extend_simple_arg (struct value *arg)
1333{
1334 struct type *type = VALUE_TYPE (arg);
1335
1336 /* Even structs get passed in the least significant bits of the
1337 register / memory word. It's not really right to extract them as
1338 an integer, but it does take care of the extension. */
1339 if (TYPE_UNSIGNED (type))
1340 return extract_unsigned_integer (VALUE_CONTENTS (arg),
1341 TYPE_LENGTH (type));
1342 else
1343 return extract_signed_integer (VALUE_CONTENTS (arg),
1344 TYPE_LENGTH (type));
1345}
1346
1347
1348/* Return non-zero if TYPE is a `DOUBLE_ARG', as defined by the
1349 parameter passing conventions described in the "Linux for S/390 ELF
1350 Application Binary Interface Supplement". Return zero otherwise. */
1351static int
1352is_double_arg (struct type *type)
1353{
78f8b424
JB		 1354 unsigned length = TYPE_LENGTH (type);
1355
1356 return ((is_integer_like (type)
20a940cc 1357 || is_struct_like (type))
78f8b424
JB		 1358 && length == 8);
1359}
1360
1361
1362/* Round ADDR up to the next N-byte boundary. N must be a power of
1363 two. */
1364static CORE_ADDR
1365round_up (CORE_ADDR addr, int n)
1366{
1367 /* Check that N is really a power of two. */
1368 gdb_assert (n && (n & (n-1)) == 0);
1369 return ((addr + n - 1) & -n);
1370}
1371
1372
1373/* Round ADDR down to the next N-byte boundary. N must be a power of
1374 two. */
1375static CORE_ADDR
1376round_down (CORE_ADDR addr, int n)
1377{
1378 /* Check that N is really a power of two. */
1379 gdb_assert (n && (n & (n-1)) == 0);
1380 return (addr & -n);
1381}
1382
1383
1384/* Return the alignment required by TYPE. */
1385static int
1386alignment_of (struct type *type)
1387{
1388 int alignment;
1389
1390 if (is_integer_like (type)
1391 || is_pointer_like (type)
1392 || TYPE_CODE (type) == TYPE_CODE_FLT)
1393 alignment = TYPE_LENGTH (type);
1394 else if (TYPE_CODE (type) == TYPE_CODE_STRUCT
1395 || TYPE_CODE (type) == TYPE_CODE_UNION)
1396 {
1397 int i;
1398
1399 alignment = 1;
1400 for (i = 0; i < TYPE_NFIELDS (type); i++)
1401 {
1402 int field_alignment = alignment_of (TYPE_FIELD_TYPE (type, i));
1403
1404 if (field_alignment > alignment)
1405 alignment = field_alignment;
1406 }
1407 }
1408 else
1409 alignment = 1;
1410
1411 /* Check that everything we ever return is a power of two. Lots of
1412 code doesn't want to deal with aligning things to arbitrary
1413 boundaries. */
1414 gdb_assert ((alignment & (alignment - 1)) == 0);
1415
1416 return alignment;
1417}
1418
1419
1420/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in
1421 place to be passed to a function, as specified by the "Linux for
1422 S/390 ELF Application Binary Interface Supplement".
1423
1424 SP is the current stack pointer. We must put arguments, links,
1425 padding, etc. whereever they belong, and return the new stack
1426 pointer value.
1427
1428 If STRUCT_RETURN is non-zero, then the function we're calling is
1429 going to return a structure by value; STRUCT_ADDR is the address of
1430 a block we've allocated for it on the stack.
1431
1432 Our caller has taken care of any type promotions needed to satisfy
1433 prototypes or the old K&R argument-passing rules. */
5769d3cd 1434CORE_ADDR
d45fc520 1435s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
5769d3cd
AC		 1436 int struct_return, CORE_ADDR struct_addr)
1437{
78f8b424
JB		 1438 int i;
1439 int pointer_size = (TARGET_PTR_BIT / TARGET_CHAR_BIT);
5769d3cd 1440
78f8b424
JB		 1441 /* The number of arguments passed by reference-to-copy. */
1442 int num_copies;
5769d3cd 1443
78f8b424
JB		 1444 /* If the i'th argument is passed as a reference to a copy, then
1445 copy_addr[i] is the address of the copy we made. */
1446 CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
5769d3cd 1447
78f8b424
JB		 1448 /* Build the reference-to-copy area. */
1449 num_copies = 0;
1450 for (i = 0; i < nargs; i++)
1451 {
1452 struct value *arg = args[i];
1453 struct type *type = VALUE_TYPE (arg);
1454 unsigned length = TYPE_LENGTH (type);
5769d3cd 1455
78f8b424
JB		 1456 if (is_simple_arg (type)
1457 && pass_by_copy_ref (type))
01c464e9 1458 {
78f8b424
JB		 1459 sp -= length;
1460 sp = round_down (sp, alignment_of (type));
1461 write_memory (sp, VALUE_CONTENTS (arg), length);
1462 copy_addr[i] = sp;
1463 num_copies++;
01c464e9 1464 }
5769d3cd 1465 }
5769d3cd 1466
78f8b424
JB		 1467 /* Reserve space for the parameter area. As a conservative
1468 simplification, we assume that everything will be passed on the
1469 stack. */
1470 {
1471 int i;
1472
1473 for (i = 0; i < nargs; i++)
1474 {
1475 struct value *arg = args[i];
1476 struct type *type = VALUE_TYPE (arg);
1477 int length = TYPE_LENGTH (type);
1478
1479 sp = round_down (sp, alignment_of (type));
1480
1481 /* SIMPLE_ARG values get extended to 32 bits. Assume every
1482 argument is. */
1483 if (length < 4) length = 4;
1484 sp -= length;
1485 }
1486 }
1487
1488 /* Include space for any reference-to-copy pointers. */
1489 sp = round_down (sp, pointer_size);
1490 sp -= num_copies * pointer_size;
1491
1492 /* After all that, make sure it's still aligned on an eight-byte
1493 boundary. */
1494 sp = round_down (sp, 8);
1495
1496 /* Finally, place the actual parameters, working from SP towards
1497 higher addresses. The code above is supposed to reserve enough
1498 space for this. */
1499 {
1500 int fr = 0;
1501 int gr = 2;
1502 CORE_ADDR starg = sp;
1503
1504 for (i = 0; i < nargs; i++)
1505 {
1506 struct value *arg = args[i];
1507 struct type *type = VALUE_TYPE (arg);
1508
1509 if (is_double_or_float (type)
1510 && fr <= 2)
1511 {
1512 /* When we store a single-precision value in an FP register,
1513 it occupies the leftmost bits. */
1514 write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM + fr),
1515 VALUE_CONTENTS (arg),
1516 TYPE_LENGTH (type));
1517 fr += 2;
1518 }
1519 else if (is_simple_arg (type)
1520 && gr <= 6)
1521 {
1522 /* Do we need to pass a pointer to our copy of this
1523 argument? */
1524 if (pass_by_copy_ref (type))
1525 write_register (S390_GP0_REGNUM + gr, copy_addr[i]);
1526 else
1527 write_register (S390_GP0_REGNUM + gr, extend_simple_arg (arg));
1528
1529 gr++;
1530 }
1531 else if (is_double_arg (type)
1532 && gr <= 5)
1533 {
1534 write_register_gen (S390_GP0_REGNUM + gr,
1535 VALUE_CONTENTS (arg));
1536 write_register_gen (S390_GP0_REGNUM + gr + 1,
1537 VALUE_CONTENTS (arg) + 4);
1538 gr += 2;
1539 }
1540 else
1541 {
1542 /* The `OTHER' case. */
1543 enum type_code code = TYPE_CODE (type);
1544 unsigned length = TYPE_LENGTH (type);
1545
1546 /* If we skipped r6 because we couldn't fit a DOUBLE_ARG
1547 in it, then don't go back and use it again later. */
1548 if (is_double_arg (type) && gr == 6)
1549 gr = 7;
1550
1551 if (is_simple_arg (type))
1552 {
1553 /* Simple args are always either extended to 32 bits,
1554 or pointers. */
1555 starg = round_up (starg, 4);
1556
1557 /* Do we need to pass a pointer to our copy of this
1558 argument? */
1559 if (pass_by_copy_ref (type))
1560 write_memory_signed_integer (starg, pointer_size,
1561 copy_addr[i]);
1562 else
1563 /* Simple args are always extended to 32 bits. */
1564 write_memory_signed_integer (starg, 4,
1565 extend_simple_arg (arg));
1566 starg += 4;
1567 }
1568 else
1569 {
20a940cc
JB		 1570 /* You'd think we should say:
1571 starg = round_up (starg, alignment_of (type));
1572 Unfortunately, GCC seems to simply align the stack on
1573 a four-byte boundary, even when passing doubles. */
1574 starg = round_up (starg, 4);
78f8b424
JB		 1575 write_memory (starg, VALUE_CONTENTS (arg), length);
1576 starg += length;
1577 }
1578 }
1579 }
1580 }
1581
1582 /* Allocate the standard frame areas: the register save area, the
1583 word reserved for the compiler (which seems kind of meaningless),
1584 and the back chain pointer. */
1585 sp -= 96;
1586
1587 /* Write the back chain pointer into the first word of the stack
1588 frame. This will help us get backtraces from within functions
1589 called from GDB. */
1590 write_memory_unsigned_integer (sp, (TARGET_PTR_BIT / TARGET_CHAR_BIT),
1591 read_fp ());
1592
1593 return sp;
5769d3cd
AC		 1594}
1595
5769d3cd
AC		 1596/* Return the GDB type object for the "standard" data type
1597 of data in register N. */
1598struct type *
1599s390_register_virtual_type (int regno)
1600{
1601 return ((unsigned) regno - S390_FPC_REGNUM) <
1602 S390_NUM_FPRS ? builtin_type_double : builtin_type_int;
1603}
1604
1605
1606struct type *
1607s390x_register_virtual_type (int regno)
1608{
1609 return (regno == S390_FPC_REGNUM) ||
1610 (regno >= S390_FIRST_ACR && regno <= S390_LAST_ACR) ? builtin_type_int :
1611 (regno >= S390_FP0_REGNUM) ? builtin_type_double : builtin_type_long;
1612}
1613
1614
1615
1616void
1617s390_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
1618{
1619 write_register (S390_GP0_REGNUM + 2, addr);
1620}
1621
1622
1623
1624static unsigned char *
1625s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
1626{
1627 static unsigned char breakpoint[] = { 0x0, 0x1 };
1628
1629 *lenptr = sizeof (breakpoint);
1630 return breakpoint;
1631}
1632
1633/* Advance PC across any function entry prologue instructions to reach some
1634 "real" code. */
1635CORE_ADDR
1636s390_skip_prologue (CORE_ADDR pc)
1637{
1638 struct frame_extra_info fextra_info;
1639
1640 s390_get_frame_info (pc, &fextra_info, NULL, 1);
1641 return fextra_info.skip_prologue_function_start;
1642}
1643
5769d3cd
AC		 1644/* Immediately after a function call, return the saved pc.
1645 Can't go through the frames for this because on some machines
1646 the new frame is not set up until the new function executes
1647 some instructions. */
1648CORE_ADDR
1649s390_saved_pc_after_call (struct frame_info *frame)
1650{
1651 return ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
1652}
1653
1654static CORE_ADDR
1655s390_addr_bits_remove (CORE_ADDR addr)
1656{
1657 return (addr) & 0x7fffffff;
1658}
1659
1660
1661static CORE_ADDR
1662s390_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
1663{
d4d0c21e 1664 write_register (S390_RETADDR_REGNUM, CALL_DUMMY_ADDRESS ());
5769d3cd
AC		 1665 return sp;
1666}
1667
1668struct gdbarch *
1669s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1670{
d4d0c21e 1671 static LONGEST s390_call_dummy_words[] = { 0 };
5769d3cd
AC		 1672 struct gdbarch *gdbarch;
1673 struct gdbarch_tdep *tdep;
1674 int elf_flags;
1675
1676 /* First see if there is already a gdbarch that can satisfy the request. */
1677 arches = gdbarch_list_lookup_by_info (arches, &info);
1678 if (arches != NULL)
1679 return arches->gdbarch;
1680
1681 /* None found: is the request for a s390 architecture? */
1682 if (info.bfd_arch_info->arch != bfd_arch_s390)
1683 return NULL; /* No; then it's not for us. */
1684
1685 /* Yes: create a new gdbarch for the specified machine type. */
1686 gdbarch = gdbarch_alloc (&info, NULL);
1687
1688 set_gdbarch_believe_pcc_promotion (gdbarch, 0);
1689
5769d3cd
AC		 1690 set_gdbarch_frame_args_skip (gdbarch, 0);
1691 set_gdbarch_frame_args_address (gdbarch, s390_frame_args_address);
1692 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1693 set_gdbarch_frame_init_saved_regs (gdbarch, s390_frame_init_saved_regs);
1694 set_gdbarch_frame_locals_address (gdbarch, s390_frame_args_address);
1695 /* We can't do this */
1696 set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
1697 set_gdbarch_store_struct_return (gdbarch, s390_store_struct_return);
1698 set_gdbarch_extract_return_value (gdbarch, s390_extract_return_value);
1699 set_gdbarch_store_return_value (gdbarch, s390_store_return_value);
1700 /* Amount PC must be decremented by after a breakpoint.
1701 This is often the number of bytes in BREAKPOINT
1702 but not always. */
1703 set_gdbarch_decr_pc_after_break (gdbarch, 2);
1704 set_gdbarch_pop_frame (gdbarch, s390_pop_frame);
5769d3cd
AC		 1705 set_gdbarch_ieee_float (gdbarch, 1);
1706 /* Stack grows downward. */
1707 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1708 /* Offset from address of function to start of its code.
1709 Zero on most machines. */
1710 set_gdbarch_function_start_offset (gdbarch, 0);
1711 set_gdbarch_max_register_raw_size (gdbarch, 8);
1712 set_gdbarch_max_register_virtual_size (gdbarch, 8);
1713 set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc);
1714 set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue);
1715 set_gdbarch_init_extra_frame_info (gdbarch, s390_init_extra_frame_info);
1716 set_gdbarch_init_frame_pc_first (gdbarch, s390_init_frame_pc_first);
1717 set_gdbarch_read_fp (gdbarch, s390_read_fp);
1718 set_gdbarch_write_fp (gdbarch, s390_write_fp);
1719 /* This function that tells us whether the function invocation represented
1720 by FI does not have a frame on the stack associated with it. If it
1721 does not, FRAMELESS is set to 1, else 0. */
1722 set_gdbarch_frameless_function_invocation (gdbarch,
1723 s390_frameless_function_invocation);
1724 /* Return saved PC from a frame */
1725 set_gdbarch_frame_saved_pc (gdbarch, s390_frame_saved_pc);
1726 /* FRAME_CHAIN takes a frame's nominal address
1727 and produces the frame's chain-pointer. */
1728 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1729 set_gdbarch_saved_pc_after_call (gdbarch, s390_saved_pc_after_call);
1730 set_gdbarch_register_byte (gdbarch, s390_register_byte);
1731 set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM);
1732 set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM);
1733 set_gdbarch_fp_regnum (gdbarch, S390_FP_REGNUM);
1734 set_gdbarch_fp0_regnum (gdbarch, S390_FP0_REGNUM);
1735 set_gdbarch_num_regs (gdbarch, S390_NUM_REGS);
1736 set_gdbarch_cannot_fetch_register (gdbarch, s390_cannot_fetch_register);
1737 set_gdbarch_cannot_store_register (gdbarch, s390_cannot_fetch_register);
1738 set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
1739 set_gdbarch_use_struct_convention (gdbarch, generic_use_struct_convention);
8001d1e4 1740 set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid);
5769d3cd
AC		 1741 set_gdbarch_register_name (gdbarch, s390_register_name);
1742 set_gdbarch_stab_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1743 set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1744 set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
5769d3cd 1745
d4d0c21e 1746 /* Parameters for inferior function calls. */
5769d3cd 1747 set_gdbarch_call_dummy_p (gdbarch, 1);
d4d0c21e
JB		 1748 set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
1749 set_gdbarch_call_dummy_length (gdbarch, 0);
1750 set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
1751 set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
1752 set_gdbarch_call_dummy_start_offset (gdbarch, 0);
1753 set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_at_entry_point);
1754 set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
1755 set_gdbarch_push_arguments (gdbarch, s390_push_arguments);
1756 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1757 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
5769d3cd
AC		 1758 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1759 set_gdbarch_extract_struct_value_address (gdbarch, 0);
d4d0c21e 1760 set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
5769d3cd 1761 set_gdbarch_push_return_address (gdbarch, s390_push_return_address);
d4d0c21e
JB		 1762 set_gdbarch_sizeof_call_dummy_words (gdbarch,
1763 sizeof (s390_call_dummy_words));
1764 set_gdbarch_call_dummy_words (gdbarch, s390_call_dummy_words);
0adb2aba
JB		 1765 set_gdbarch_coerce_float_to_double (gdbarch,
1766 standard_coerce_float_to_double);
5769d3cd
AC		 1767
1768 switch (info.bfd_arch_info->mach)
1769 {
1770 case bfd_mach_s390_esa:
1771 set_gdbarch_register_size (gdbarch, 4);
5769d3cd
AC		 1772 set_gdbarch_register_raw_size (gdbarch, s390_register_raw_size);
1773 set_gdbarch_register_virtual_size (gdbarch, s390_register_raw_size);
1774 set_gdbarch_register_virtual_type (gdbarch, s390_register_virtual_type);
1775
1776 set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove);
5769d3cd
AC		 1777 set_gdbarch_register_bytes (gdbarch, S390_REGISTER_BYTES);
1778 break;
1779 case bfd_mach_s390_esame:
1780 set_gdbarch_register_size (gdbarch, 8);
5769d3cd
AC		 1781 set_gdbarch_register_raw_size (gdbarch, s390x_register_raw_size);
1782 set_gdbarch_register_virtual_size (gdbarch, s390x_register_raw_size);
1783 set_gdbarch_register_virtual_type (gdbarch,
1784 s390x_register_virtual_type);
1785
1786 set_gdbarch_long_bit (gdbarch, 64);
1787 set_gdbarch_long_long_bit (gdbarch, 64);
1788 set_gdbarch_ptr_bit (gdbarch, 64);
5769d3cd
AC		 1789 set_gdbarch_register_bytes (gdbarch, S390X_REGISTER_BYTES);
1790 break;
1791 }
1792
1793 return gdbarch;
1794}
1795
1796
1797
1798void
1799_initialize_s390_tdep ()
1800{
1801
1802 /* Hook us into the gdbarch mechanism. */
1803 register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init);
1804 if (!tm_print_insn) /* Someone may have already set it */
1805 tm_print_insn = gdb_print_insn_s390;
1806}
1807
1808#endif /* GDBSERVER */
GDB Binutils - Deliverables
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