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2003-01-07 Andrew Cagney <cagney@redhat.com>
[deliverable/binutils-gdb.git] / gdb / s390-tdep.c
... / ...
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1/* Target-dependent code for GDB, the GNU debugger.
2
3 Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
4
5 Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
6 for IBM Deutschland Entwicklung GmbH, IBM Corporation.
7
8 This file is part of GDB.
9
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
14
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 02111-1307, USA. */
24
25#define S390_TDEP /* for special macros in tm-s390.h */
26#include <defs.h>
27#include "arch-utils.h"
28#include "frame.h"
29#include "inferior.h"
30#include "symtab.h"
31#include "target.h"
32#include "gdbcore.h"
33#include "gdbcmd.h"
34#include "symfile.h"
35#include "objfiles.h"
36#include "tm.h"
37#include "../bfd/bfd.h"
38#include "floatformat.h"
39#include "regcache.h"
40#include "value.h"
41#include "gdb_assert.h"
42
43
44
45
46/* Number of bytes of storage in the actual machine representation
47 for register N. */
48int
49s390_register_raw_size (int reg_nr)
50{
51 if (S390_FP0_REGNUM <= reg_nr
52 && reg_nr < S390_FP0_REGNUM + S390_NUM_FPRS)
53 return S390_FPR_SIZE;
54 else
55 return 4;
56}
57
58int
59s390x_register_raw_size (int reg_nr)
60{
61 return (reg_nr == S390_FPC_REGNUM)
62 || (reg_nr >= S390_FIRST_ACR && reg_nr <= S390_LAST_ACR) ? 4 : 8;
63}
64
65int
66s390_cannot_fetch_register (int regno)
67{
68 return (regno >= S390_FIRST_CR && regno < (S390_FIRST_CR + 9)) ||
69 (regno >= (S390_FIRST_CR + 12) && regno <= S390_LAST_CR);
70}
71
72int
73s390_register_byte (int reg_nr)
74{
75 if (reg_nr <= S390_GP_LAST_REGNUM)
76 return reg_nr * S390_GPR_SIZE;
77 if (reg_nr <= S390_LAST_ACR)
78 return S390_ACR0_OFFSET + (((reg_nr) - S390_FIRST_ACR) * S390_ACR_SIZE);
79 if (reg_nr <= S390_LAST_CR)
80 return S390_CR0_OFFSET + (((reg_nr) - S390_FIRST_CR) * S390_CR_SIZE);
81 if (reg_nr == S390_FPC_REGNUM)
82 return S390_FPC_OFFSET;
83 else
84 return S390_FP0_OFFSET + (((reg_nr) - S390_FP0_REGNUM) * S390_FPR_SIZE);
85}
86
87#ifndef GDBSERVER
88#define S390_MAX_INSTR_SIZE (6)
89#define S390_SYSCALL_OPCODE (0x0a)
90#define S390_SYSCALL_SIZE (2)
91#define S390_SIGCONTEXT_SREGS_OFFSET (8)
92#define S390X_SIGCONTEXT_SREGS_OFFSET (8)
93#define S390_SIGREGS_FP0_OFFSET (144)
94#define S390X_SIGREGS_FP0_OFFSET (216)
95#define S390_UC_MCONTEXT_OFFSET (256)
96#define S390X_UC_MCONTEXT_OFFSET (344)
97#define S390_STACK_FRAME_OVERHEAD (GDB_TARGET_IS_ESAME ? 160:96)
98#define S390_SIGNAL_FRAMESIZE (GDB_TARGET_IS_ESAME ? 160:96)
99#define s390_NR_sigreturn 119
100#define s390_NR_rt_sigreturn 173
101
102
103
104struct frame_extra_info
105{
106 int initialised;
107 int good_prologue;
108 CORE_ADDR function_start;
109 CORE_ADDR skip_prologue_function_start;
110 CORE_ADDR saved_pc_valid;
111 CORE_ADDR saved_pc;
112 CORE_ADDR sig_fixed_saved_pc_valid;
113 CORE_ADDR sig_fixed_saved_pc;
114 CORE_ADDR frame_pointer_saved_pc; /* frame pointer needed for alloca */
115 CORE_ADDR stack_bought; /* amount we decrement the stack pointer by */
116 CORE_ADDR sigcontext;
117};
118
119
120static CORE_ADDR s390_frame_saved_pc_nofix (struct frame_info *fi);
121
122int
123s390_readinstruction (bfd_byte instr[], CORE_ADDR at,
124 struct disassemble_info *info)
125{
126 int instrlen;
127
128 static int s390_instrlen[] = {
129 2,
130 4,
131 4,
132 6
133 };
134 if ((*info->read_memory_func) (at, &instr[0], 2, info))
135 return -1;
136 instrlen = s390_instrlen[instr[0] >> 6];
137 if (instrlen > 2)
138 {
139 if ((*info->read_memory_func) (at + 2, &instr[2], instrlen - 2, info))
140 return -1;
141 }
142 return instrlen;
143}
144
145static void
146s390_memset_extra_info (struct frame_extra_info *fextra_info)
147{
148 memset (fextra_info, 0, sizeof (struct frame_extra_info));
149}
150
151
152
153const char *
154s390_register_name (int reg_nr)
155{
156 static char *register_names[] = {
157 "pswm", "pswa",
158 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
159 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
160 "acr0", "acr1", "acr2", "acr3", "acr4", "acr5", "acr6", "acr7",
161 "acr8", "acr9", "acr10", "acr11", "acr12", "acr13", "acr14", "acr15",
162 "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7",
163 "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15",
164 "fpc",
165 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
166 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15"
167 };
168
169 if (reg_nr <= S390_LAST_REGNUM)
170 return register_names[reg_nr];
171 else
172 return NULL;
173}
174
175
176
177
178int
179s390_stab_reg_to_regnum (int regno)
180{
181 return regno >= 64 ? S390_PSWM_REGNUM - 64 :
182 regno >= 48 ? S390_FIRST_ACR - 48 :
183 regno >= 32 ? S390_FIRST_CR - 32 :
184 regno <= 15 ? (regno + 2) :
185 S390_FP0_REGNUM + ((regno - 16) & 8) + (((regno - 16) & 3) << 1) +
186 (((regno - 16) & 4) >> 2);
187}
188
189
190/* Return true if REGIDX is the number of a register used to pass
191 arguments, false otherwise. */
192static int
193is_arg_reg (int regidx)
194{
195 return 2 <= regidx && regidx <= 6;
196}
197
198
199/* s390_get_frame_info based on Hartmuts
200 prologue definition in
201 gcc-2.8.1/config/l390/linux.c
202
203 It reads one instruction at a time & based on whether
204 it looks like prologue code or not it makes a decision on
205 whether the prologue is over, there are various state machines
206 in the code to determine if the prologue code is possilby valid.
207
208 This is done to hopefully allow the code survive minor revs of
209 calling conventions.
210
211 */
212
213int
214s390_get_frame_info (CORE_ADDR pc, struct frame_extra_info *fextra_info,
215 struct frame_info *fi, int init_extra_info)
216{
217#define CONST_POOL_REGIDX 13
218#define GOT_REGIDX 12
219 bfd_byte instr[S390_MAX_INSTR_SIZE];
220 CORE_ADDR test_pc = pc, test_pc2;
221 CORE_ADDR orig_sp = 0, save_reg_addr = 0, *saved_regs = NULL;
222 int valid_prologue, good_prologue = 0;
223 int gprs_saved[S390_NUM_GPRS];
224 int fprs_saved[S390_NUM_FPRS];
225 int regidx, instrlen;
226 int const_pool_state;
227 int varargs_state;
228 int loop_cnt, gdb_gpr_store, gdb_fpr_store;
229 int offset, expected_offset;
230 int err = 0;
231 disassemble_info info;
232
233 /* Have we seen an instruction initializing the frame pointer yet?
234 If we've seen an `lr %r11, %r15', then frame_pointer_found is
235 non-zero, and frame_pointer_regidx == 11. Otherwise,
236 frame_pointer_found is zero and frame_pointer_regidx is 15,
237 indicating that we're using the stack pointer as our frame
238 pointer. */
239 int frame_pointer_found = 0;
240 int frame_pointer_regidx = 0xf;
241
242 /* What we've seen so far regarding saving the back chain link:
243 0 -- nothing yet; sp still has the same value it had at the entry
244 point. Since not all functions allocate frames, this is a
245 valid state for the prologue to finish in.
246 1 -- We've saved the original sp in some register other than the
247 frame pointer (hard-coded to be %r11, yuck).
248 save_link_regidx is the register we saved it in.
249 2 -- We've seen the initial `bras' instruction of the sequence for
250 reserving more than 32k of stack:
251 bras %rX, .+8
252 .long N
253 s %r15, 0(%rX)
254 where %rX is not the constant pool register.
255 subtract_sp_regidx is %rX, and fextra_info->stack_bought is N.
256 3 -- We've reserved space for a new stack frame. This means we
257 either saw a simple `ahi %r15,-N' in state 1, or the final
258 `s %r15, ...' in state 2.
259 4 -- The frame and link are now fully initialized. We've
260 reserved space for the new stack frame, and stored the old
261 stack pointer captured in the back chain pointer field. */
262 int save_link_state = 0;
263 int save_link_regidx, subtract_sp_regidx;
264
265 /* What we've seen so far regarding r12 --- the GOT (Global Offset
266 Table) pointer. We expect to see `l %r12, N(%r13)', which loads
267 r12 with the offset from the constant pool to the GOT, and then
268 an `ar %r12, %r13', which adds the constant pool address,
269 yielding the GOT's address. Here's what got_state means:
270 0 -- seen nothing
271 1 -- seen `l %r12, N(%r13)', but no `ar'
272 2 -- seen load and add, so GOT pointer is totally initialized
273 When got_state is 1, then got_load_addr is the address of the
274 load instruction, and got_load_len is the length of that
275 instruction. */
276 int got_state= 0;
277 CORE_ADDR got_load_addr = 0, got_load_len = 0;
278
279 const_pool_state = varargs_state = 0;
280
281 memset (gprs_saved, 0, sizeof (gprs_saved));
282 memset (fprs_saved, 0, sizeof (fprs_saved));
283 info.read_memory_func = dis_asm_read_memory;
284
285 save_link_regidx = subtract_sp_regidx = 0;
286 if (fextra_info)
287 {
288 if (fi && get_frame_base (fi))
289 {
290 orig_sp = get_frame_base (fi);
291 if (! init_extra_info && fextra_info->initialised)
292 orig_sp += fextra_info->stack_bought;
293 saved_regs = get_frame_saved_regs (fi);
294 }
295 if (init_extra_info || !fextra_info->initialised)
296 {
297 s390_memset_extra_info (fextra_info);
298 fextra_info->function_start = pc;
299 fextra_info->initialised = 1;
300 }
301 }
302 instrlen = 0;
303 do
304 {
305 valid_prologue = 0;
306 test_pc += instrlen;
307 /* add the previous instruction len */
308 instrlen = s390_readinstruction (instr, test_pc, &info);
309 if (instrlen < 0)
310 {
311 good_prologue = 0;
312 err = -1;
313 break;
314 }
315 /* We probably are in a glibc syscall */
316 if (instr[0] == S390_SYSCALL_OPCODE && test_pc == pc)
317 {
318 good_prologue = 1;
319 if (saved_regs && fextra_info && fi->next && fi->next->extra_info
320 && fi->next->extra_info->sigcontext)
321 {
322 /* We are backtracing from a signal handler */
323 save_reg_addr = fi->next->extra_info->sigcontext +
324 REGISTER_BYTE (S390_GP0_REGNUM);
325 for (regidx = 0; regidx < S390_NUM_GPRS; regidx++)
326 {
327 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
328 save_reg_addr += S390_GPR_SIZE;
329 }
330 save_reg_addr = fi->next->extra_info->sigcontext +
331 (GDB_TARGET_IS_ESAME ? S390X_SIGREGS_FP0_OFFSET :
332 S390_SIGREGS_FP0_OFFSET);
333 for (regidx = 0; regidx < S390_NUM_FPRS; regidx++)
334 {
335 saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
336 save_reg_addr += S390_FPR_SIZE;
337 }
338 }
339 break;
340 }
341 if (save_link_state == 0)
342 {
343 /* check for a stack relative STMG or STM */
344 if (((GDB_TARGET_IS_ESAME &&
345 ((instr[0] == 0xeb) && (instr[5] == 0x24))) ||
346 (instr[0] == 0x90)) && ((instr[2] >> 4) == 0xf))
347 {
348 regidx = (instr[1] >> 4);
349 if (regidx < 6)
350 varargs_state = 1;
351 offset = ((instr[2] & 0xf) << 8) + instr[3];
352 expected_offset =
353 S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
354 if (offset != expected_offset)
355 {
356 good_prologue = 0;
357 break;
358 }
359 if (saved_regs)
360 save_reg_addr = orig_sp + offset;
361 for (; regidx <= (instr[1] & 0xf); regidx++)
362 {
363 if (gprs_saved[regidx])
364 {
365 good_prologue = 0;
366 break;
367 }
368 good_prologue = 1;
369 gprs_saved[regidx] = 1;
370 if (saved_regs)
371 {
372 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
373 save_reg_addr += S390_GPR_SIZE;
374 }
375 }
376 valid_prologue = 1;
377 continue;
378 }
379 }
380 /* check for a stack relative STG or ST */
381 if ((save_link_state == 0 || save_link_state == 3) &&
382 ((GDB_TARGET_IS_ESAME &&
383 ((instr[0] == 0xe3) && (instr[5] == 0x24))) ||
384 (instr[0] == 0x50)) && ((instr[2] >> 4) == 0xf))
385 {
386 regidx = instr[1] >> 4;
387 offset = ((instr[2] & 0xf) << 8) + instr[3];
388 if (offset == 0)
389 {
390 if (save_link_state == 3 && regidx == save_link_regidx)
391 {
392 save_link_state = 4;
393 valid_prologue = 1;
394 continue;
395 }
396 else
397 break;
398 }
399 if (regidx < 6)
400 varargs_state = 1;
401 expected_offset =
402 S390_GPR6_STACK_OFFSET + (S390_GPR_SIZE * (regidx - 6));
403 if (offset != expected_offset)
404 {
405 good_prologue = 0;
406 break;
407 }
408 if (gprs_saved[regidx])
409 {
410 good_prologue = 0;
411 break;
412 }
413 good_prologue = 1;
414 gprs_saved[regidx] = 1;
415 if (saved_regs)
416 {
417 save_reg_addr = orig_sp + offset;
418 saved_regs[S390_GP0_REGNUM + regidx] = save_reg_addr;
419 }
420 valid_prologue = 1;
421 continue;
422 }
423
424 /* Check for an fp-relative STG, ST, or STM. This is probably
425 spilling an argument from a register out into a stack slot.
426 This could be a user instruction, but if we haven't included
427 any other suspicious instructions in the prologue, this
428 could only be an initializing store, which isn't too bad to
429 skip. The consequences of not including arg-to-stack spills
430 are more serious, though --- you don't see the proper values
431 of the arguments. */
432 if ((save_link_state == 3 || save_link_state == 4)
433 && ((instr[0] == 0x50 /* st %rA, D(%rX,%rB) */
434 && (instr[1] & 0xf) == 0 /* %rX is zero, no index reg */
435 && is_arg_reg ((instr[1] >> 4) & 0xf)
436 && ((instr[2] >> 4) & 0xf) == frame_pointer_regidx)
437 || (instr[0] == 0x90 /* stm %rA, %rB, D(%rC) */
438 && is_arg_reg ((instr[1] >> 4) & 0xf)
439 && is_arg_reg (instr[1] & 0xf)
440 && ((instr[2] >> 4) & 0xf) == frame_pointer_regidx)))
441 {
442 valid_prologue = 1;
443 continue;
444 }
445
446 /* check for STD */
447 if (instr[0] == 0x60 && (instr[2] >> 4) == 0xf)
448 {
449 regidx = instr[1] >> 4;
450 if (regidx == 0 || regidx == 2)
451 varargs_state = 1;
452 if (fprs_saved[regidx])
453 {
454 good_prologue = 0;
455 break;
456 }
457 fprs_saved[regidx] = 1;
458 if (saved_regs)
459 {
460 save_reg_addr = orig_sp + (((instr[2] & 0xf) << 8) + instr[3]);
461 saved_regs[S390_FP0_REGNUM + regidx] = save_reg_addr;
462 }
463 valid_prologue = 1;
464 continue;
465 }
466
467
468 if (const_pool_state == 0)
469 {
470
471 if (GDB_TARGET_IS_ESAME)
472 {
473 /* Check for larl CONST_POOL_REGIDX,offset on ESAME */
474 if ((instr[0] == 0xc0)
475 && (instr[1] == (CONST_POOL_REGIDX << 4)))
476 {
477 const_pool_state = 2;
478 valid_prologue = 1;
479 continue;
480 }
481 }
482 else
483 {
484 /* Check for BASR gpr13,gpr0 used to load constant pool pointer to r13 in old compiler */
485 if (instr[0] == 0xd && (instr[1] & 0xf) == 0
486 && ((instr[1] >> 4) == CONST_POOL_REGIDX))
487 {
488 const_pool_state = 1;
489 valid_prologue = 1;
490 continue;
491 }
492 }
493 /* Check for new fangled bras %r13,newpc to load new constant pool */
494 /* embedded in code, older pre abi compilers also emitted this stuff. */
495 if ((instr[0] == 0xa7) && ((instr[1] & 0xf) == 0x5) &&
496 ((instr[1] >> 4) == CONST_POOL_REGIDX)
497 && ((instr[2] & 0x80) == 0))
498 {
499 const_pool_state = 2;
500 test_pc +=
501 (((((instr[2] & 0xf) << 8) + instr[3]) << 1) - instrlen);
502 valid_prologue = 1;
503 continue;
504 }
505 }
506 /* Check for AGHI or AHI CONST_POOL_REGIDX,val */
507 if (const_pool_state == 1 && (instr[0] == 0xa7) &&
508 ((GDB_TARGET_IS_ESAME &&
509 (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xb))) ||
510 (instr[1] == ((CONST_POOL_REGIDX << 4) | 0xa))))
511 {
512 const_pool_state = 2;
513 valid_prologue = 1;
514 continue;
515 }
516 /* Check for LGR or LR gprx,15 */
517 if ((GDB_TARGET_IS_ESAME &&
518 instr[0] == 0xb9 && instr[1] == 0x04 && (instr[3] & 0xf) == 0xf) ||
519 (instr[0] == 0x18 && (instr[1] & 0xf) == 0xf))
520 {
521 if (GDB_TARGET_IS_ESAME)
522 regidx = instr[3] >> 4;
523 else
524 regidx = instr[1] >> 4;
525 if (save_link_state == 0 && regidx != 0xb)
526 {
527 /* Almost defintely code for
528 decrementing the stack pointer
529 ( i.e. a non leaf function
530 or else leaf with locals ) */
531 save_link_regidx = regidx;
532 save_link_state = 1;
533 valid_prologue = 1;
534 continue;
535 }
536 /* We use this frame pointer for alloca
537 unfortunately we need to assume its gpr11
538 otherwise we would need a smarter prologue
539 walker. */
540 if (!frame_pointer_found && regidx == 0xb)
541 {
542 frame_pointer_regidx = 0xb;
543 frame_pointer_found = 1;
544 if (fextra_info)
545 fextra_info->frame_pointer_saved_pc = test_pc;
546 valid_prologue = 1;
547 continue;
548 }
549 }
550 /* Check for AHI or AGHI gpr15,val */
551 if (save_link_state == 1 && (instr[0] == 0xa7) &&
552 ((GDB_TARGET_IS_ESAME && (instr[1] == 0xfb)) || (instr[1] == 0xfa)))
553 {
554 if (fextra_info)
555 fextra_info->stack_bought =
556 -extract_signed_integer (&instr[2], 2);
557 save_link_state = 3;
558 valid_prologue = 1;
559 continue;
560 }
561 /* Alternatively check for the complex construction for
562 buying more than 32k of stack
563 BRAS gprx,.+8
564 long val
565 s %r15,0(%gprx) gprx currently r1 */
566 if ((save_link_state == 1) && (instr[0] == 0xa7)
567 && ((instr[1] & 0xf) == 0x5) && (instr[2] == 0)
568 && (instr[3] == 0x4) && ((instr[1] >> 4) != CONST_POOL_REGIDX))
569 {
570 subtract_sp_regidx = instr[1] >> 4;
571 save_link_state = 2;
572 if (fextra_info)
573 target_read_memory (test_pc + instrlen,
574 (char *) &fextra_info->stack_bought,
575 sizeof (fextra_info->stack_bought));
576 test_pc += 4;
577 valid_prologue = 1;
578 continue;
579 }
580 if (save_link_state == 2 && instr[0] == 0x5b
581 && instr[1] == 0xf0 &&
582 instr[2] == (subtract_sp_regidx << 4) && instr[3] == 0)
583 {
584 save_link_state = 3;
585 valid_prologue = 1;
586 continue;
587 }
588 /* check for LA gprx,offset(15) used for varargs */
589 if ((instr[0] == 0x41) && ((instr[2] >> 4) == 0xf) &&
590 ((instr[1] & 0xf) == 0))
591 {
592 /* some code uses gpr7 to point to outgoing args */
593 if (((instr[1] >> 4) == 7) && (save_link_state == 0) &&
594 ((instr[2] & 0xf) == 0)
595 && (instr[3] == S390_STACK_FRAME_OVERHEAD))
596 {
597 valid_prologue = 1;
598 continue;
599 }
600 if (varargs_state == 1)
601 {
602 varargs_state = 2;
603 valid_prologue = 1;
604 continue;
605 }
606 }
607 /* Check for a GOT load */
608
609 if (GDB_TARGET_IS_ESAME)
610 {
611 /* Check for larl GOT_REGIDX, on ESAME */
612 if ((got_state == 0) && (instr[0] == 0xc0)
613 && (instr[1] == (GOT_REGIDX << 4)))
614 {
615 got_state = 2;
616 valid_prologue = 1;
617 continue;
618 }
619 }
620 else
621 {
622 /* check for l GOT_REGIDX,x(CONST_POOL_REGIDX) */
623 if (got_state == 0 && const_pool_state == 2 && instr[0] == 0x58
624 && (instr[2] == (CONST_POOL_REGIDX << 4))
625 && ((instr[1] >> 4) == GOT_REGIDX))
626 {
627 got_state = 1;
628 got_load_addr = test_pc;
629 got_load_len = instrlen;
630 valid_prologue = 1;
631 continue;
632 }
633 /* Check for subsequent ar got_regidx,basr_regidx */
634 if (got_state == 1 && instr[0] == 0x1a &&
635 instr[1] == ((GOT_REGIDX << 4) | CONST_POOL_REGIDX))
636 {
637 got_state = 2;
638 valid_prologue = 1;
639 continue;
640 }
641 }
642 }
643 while (valid_prologue && good_prologue);
644 if (good_prologue)
645 {
646 /* If this function doesn't reference the global offset table,
647 then the compiler may use r12 for other things. If the last
648 instruction we saw was a load of r12 from the constant pool,
649 with no subsequent add to make the address PC-relative, then
650 the load was probably a genuine body instruction; don't treat
651 it as part of the prologue. */
652 if (got_state == 1
653 && got_load_addr + got_load_len == test_pc)
654 {
655 test_pc = got_load_addr;
656 instrlen = got_load_len;
657 }
658
659 good_prologue = (((const_pool_state == 0) || (const_pool_state == 2)) &&
660 ((save_link_state == 0) || (save_link_state == 4)) &&
661 ((varargs_state == 0) || (varargs_state == 2)));
662 }
663 if (fextra_info)
664 {
665 fextra_info->good_prologue = good_prologue;
666 fextra_info->skip_prologue_function_start =
667 (good_prologue ? test_pc : pc);
668 }
669 if (saved_regs)
670 /* The SP's element of the saved_regs array holds the old SP,
671 not the address at which it is saved. */
672 saved_regs[S390_SP_REGNUM] = orig_sp;
673 return err;
674}
675
676
677int
678s390_check_function_end (CORE_ADDR pc)
679{
680 bfd_byte instr[S390_MAX_INSTR_SIZE];
681 disassemble_info info;
682 int regidx, instrlen;
683
684 info.read_memory_func = dis_asm_read_memory;
685 instrlen = s390_readinstruction (instr, pc, &info);
686 if (instrlen < 0)
687 return -1;
688 /* check for BR */
689 if (instrlen != 2 || instr[0] != 07 || (instr[1] >> 4) != 0xf)
690 return 0;
691 regidx = instr[1] & 0xf;
692 /* Check for LMG or LG */
693 instrlen =
694 s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 6 : 4), &info);
695 if (instrlen < 0)
696 return -1;
697 if (GDB_TARGET_IS_ESAME)
698 {
699
700 if (instrlen != 6 || instr[0] != 0xeb || instr[5] != 0x4)
701 return 0;
702 }
703 else if (instrlen != 4 || instr[0] != 0x98)
704 {
705 return 0;
706 }
707 if ((instr[2] >> 4) != 0xf)
708 return 0;
709 if (regidx == 14)
710 return 1;
711 instrlen = s390_readinstruction (instr, pc - (GDB_TARGET_IS_ESAME ? 12 : 8),
712 &info);
713 if (instrlen < 0)
714 return -1;
715 if (GDB_TARGET_IS_ESAME)
716 {
717 /* Check for LG */
718 if (instrlen != 6 || instr[0] != 0xe3 || instr[5] != 0x4)
719 return 0;
720 }
721 else
722 {
723 /* Check for L */
724 if (instrlen != 4 || instr[0] != 0x58)
725 return 0;
726 }
727 if (instr[2] >> 4 != 0xf)
728 return 0;
729 if (instr[1] >> 4 != regidx)
730 return 0;
731 return 1;
732}
733
734static CORE_ADDR
735s390_sniff_pc_function_start (CORE_ADDR pc, struct frame_info *fi)
736{
737 CORE_ADDR function_start, test_function_start;
738 int loop_cnt, err, function_end;
739 struct frame_extra_info fextra_info;
740 function_start = get_pc_function_start (pc);
741
742 if (function_start == 0)
743 {
744 test_function_start = pc;
745 if (test_function_start & 1)
746 return 0; /* This has to be bogus */
747 loop_cnt = 0;
748 do
749 {
750
751 err =
752 s390_get_frame_info (test_function_start, &fextra_info, fi, 1);
753 loop_cnt++;
754 test_function_start -= 2;
755 function_end = s390_check_function_end (test_function_start);
756 }
757 while (!(function_end == 1 || err || loop_cnt >= 4096 ||
758 (fextra_info.good_prologue)));
759 if (fextra_info.good_prologue)
760 function_start = fextra_info.function_start;
761 else if (function_end == 1)
762 function_start = test_function_start;
763 }
764 return function_start;
765}
766
767
768
769CORE_ADDR
770s390_function_start (struct frame_info *fi)
771{
772 CORE_ADDR function_start = 0;
773
774 if (fi->extra_info && fi->extra_info->initialised)
775 function_start = fi->extra_info->function_start;
776 else if (get_frame_pc (fi))
777 function_start = get_pc_function_start (get_frame_pc (fi));
778 return function_start;
779}
780
781
782
783
784int
785s390_frameless_function_invocation (struct frame_info *fi)
786{
787 struct frame_extra_info fextra_info, *fextra_info_ptr;
788 int frameless = 0;
789
790 if (fi->next == NULL) /* no may be frameless */
791 {
792 if (fi->extra_info)
793 fextra_info_ptr = fi->extra_info;
794 else
795 {
796 fextra_info_ptr = &fextra_info;
797 s390_get_frame_info (s390_sniff_pc_function_start (get_frame_pc (fi), fi),
798 fextra_info_ptr, fi, 1);
799 }
800 frameless = ((fextra_info_ptr->stack_bought == 0));
801 }
802 return frameless;
803
804}
805
806
807static int
808s390_is_sigreturn (CORE_ADDR pc, struct frame_info *sighandler_fi,
809 CORE_ADDR *sregs, CORE_ADDR *sigcaller_pc)
810{
811 bfd_byte instr[S390_MAX_INSTR_SIZE];
812 disassemble_info info;
813 int instrlen;
814 CORE_ADDR scontext;
815 int retval = 0;
816 CORE_ADDR orig_sp;
817 CORE_ADDR temp_sregs;
818
819 scontext = temp_sregs = 0;
820
821 info.read_memory_func = dis_asm_read_memory;
822 instrlen = s390_readinstruction (instr, pc, &info);
823 if (sigcaller_pc)
824 *sigcaller_pc = 0;
825 if (((instrlen == S390_SYSCALL_SIZE) &&
826 (instr[0] == S390_SYSCALL_OPCODE)) &&
827 ((instr[1] == s390_NR_sigreturn) || (instr[1] == s390_NR_rt_sigreturn)))
828 {
829 if (sighandler_fi)
830 {
831 if (s390_frameless_function_invocation (sighandler_fi))
832 orig_sp = get_frame_base (sighandler_fi);
833 else
834 orig_sp = ADDR_BITS_REMOVE ((CORE_ADDR)
835 read_memory_integer (get_frame_base (sighandler_fi),
836 S390_GPR_SIZE));
837 if (orig_sp && sigcaller_pc)
838 {
839 scontext = orig_sp + S390_SIGNAL_FRAMESIZE;
840 if (pc == scontext && instr[1] == s390_NR_rt_sigreturn)
841 {
842 /* We got a new style rt_signal */
843 /* get address of read ucontext->uc_mcontext */
844 temp_sregs = orig_sp + (GDB_TARGET_IS_ESAME ?
845 S390X_UC_MCONTEXT_OFFSET :
846 S390_UC_MCONTEXT_OFFSET);
847 }
848 else
849 {
850 /* read sigcontext->sregs */
851 temp_sregs = ADDR_BITS_REMOVE ((CORE_ADDR)
852 read_memory_integer (scontext
853 +
854 (GDB_TARGET_IS_ESAME
855 ?
856 S390X_SIGCONTEXT_SREGS_OFFSET
857 :
858 S390_SIGCONTEXT_SREGS_OFFSET),
859 S390_GPR_SIZE));
860
861 }
862 /* read sigregs->psw.addr */
863 *sigcaller_pc =
864 ADDR_BITS_REMOVE ((CORE_ADDR)
865 read_memory_integer (temp_sregs +
866 REGISTER_BYTE
867 (S390_PC_REGNUM),
868 S390_PSW_ADDR_SIZE));
869 }
870 }
871 retval = 1;
872 }
873 if (sregs)
874 *sregs = temp_sregs;
875 return retval;
876}
877
878/*
879 We need to do something better here but this will keep us out of trouble
880 for the moment.
881 For some reason the blockframe.c calls us with fi->next->fromleaf
882 so this seems of little use to us. */
883CORE_ADDR
884s390_init_frame_pc_first (int next_fromleaf, struct frame_info *fi)
885{
886 CORE_ADDR sigcaller_pc;
887 CORE_ADDR pc = 0;
888 if (next_fromleaf)
889 {
890 pc = ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
891 /* fix signal handlers */
892 }
893 else if (get_next_frame (fi) && get_frame_pc (get_next_frame (fi)))
894 pc = s390_frame_saved_pc_nofix (get_next_frame (fi));
895 if (pc && get_next_frame (fi) && get_frame_base (get_next_frame (fi))
896 && s390_is_sigreturn (pc, get_next_frame (fi), NULL, &sigcaller_pc))
897 {
898 pc = sigcaller_pc;
899 }
900 return pc;
901}
902
903void
904s390_init_extra_frame_info (int fromleaf, struct frame_info *fi)
905{
906 frame_extra_info_zalloc (fi, sizeof (struct frame_extra_info));
907 if (get_frame_pc (fi))
908 s390_get_frame_info (s390_sniff_pc_function_start (get_frame_pc (fi), fi),
909 fi->extra_info, fi, 1);
910 else
911 s390_memset_extra_info (fi->extra_info);
912}
913
914/* If saved registers of frame FI are not known yet, read and cache them.
915 &FEXTRA_INFOP contains struct frame_extra_info; TDATAP can be NULL,
916 in which case the framedata are read. */
917
918void
919s390_frame_init_saved_regs (struct frame_info *fi)
920{
921
922 int quick;
923
924 if (get_frame_saved_regs (fi) == NULL)
925 {
926 /* zalloc memsets the saved regs */
927 frame_saved_regs_zalloc (fi);
928 if (get_frame_pc (fi))
929 {
930 quick = (fi->extra_info && fi->extra_info->initialised
931 && fi->extra_info->good_prologue);
932 s390_get_frame_info (quick ? fi->extra_info->function_start :
933 s390_sniff_pc_function_start (get_frame_pc (fi), fi),
934 fi->extra_info, fi, !quick);
935 }
936 }
937}
938
939
940
941CORE_ADDR
942s390_frame_args_address (struct frame_info *fi)
943{
944
945 /* Apparently gdb already knows gdb_args_offset itself */
946 return get_frame_base (fi);
947}
948
949
950static CORE_ADDR
951s390_frame_saved_pc_nofix (struct frame_info *fi)
952{
953 if (fi->extra_info && fi->extra_info->saved_pc_valid)
954 return fi->extra_info->saved_pc;
955
956 if (deprecated_generic_find_dummy_frame (get_frame_pc (fi),
957 get_frame_base (fi)))
958 return deprecated_read_register_dummy (get_frame_pc (fi),
959 get_frame_base (fi), S390_PC_REGNUM);
960
961 s390_frame_init_saved_regs (fi);
962 if (fi->extra_info)
963 {
964 fi->extra_info->saved_pc_valid = 1;
965 if (fi->extra_info->good_prologue
966 && get_frame_saved_regs (fi)[S390_RETADDR_REGNUM])
967 fi->extra_info->saved_pc
968 = ADDR_BITS_REMOVE (read_memory_integer
969 (get_frame_saved_regs (fi)[S390_RETADDR_REGNUM],
970 S390_GPR_SIZE));
971 else
972 fi->extra_info->saved_pc
973 = ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
974 return fi->extra_info->saved_pc;
975 }
976 return 0;
977}
978
979CORE_ADDR
980s390_frame_saved_pc (struct frame_info *fi)
981{
982 CORE_ADDR saved_pc = 0, sig_pc;
983
984 if (fi->extra_info && fi->extra_info->sig_fixed_saved_pc_valid)
985 return fi->extra_info->sig_fixed_saved_pc;
986 saved_pc = s390_frame_saved_pc_nofix (fi);
987
988 if (fi->extra_info)
989 {
990 fi->extra_info->sig_fixed_saved_pc_valid = 1;
991 if (saved_pc)
992 {
993 if (s390_is_sigreturn (saved_pc, fi, NULL, &sig_pc))
994 saved_pc = sig_pc;
995 }
996 fi->extra_info->sig_fixed_saved_pc = saved_pc;
997 }
998 return saved_pc;
999}
1000
1001
1002
1003
1004/* We want backtraces out of signal handlers so we don't set
1005 (get_frame_type (thisframe) == SIGTRAMP_FRAME) to 1 */
1006
1007CORE_ADDR
1008s390_frame_chain (struct frame_info *thisframe)
1009{
1010 CORE_ADDR prev_fp = 0;
1011
1012 if (deprecated_generic_find_dummy_frame (get_frame_pc (thisframe),
1013 get_frame_base (thisframe)))
1014 return deprecated_read_register_dummy (get_frame_pc (thisframe),
1015 get_frame_base (thisframe),
1016 S390_SP_REGNUM);
1017 else
1018 {
1019 int sigreturn = 0;
1020 CORE_ADDR sregs = 0;
1021 struct frame_extra_info prev_fextra_info;
1022
1023 memset (&prev_fextra_info, 0, sizeof (prev_fextra_info));
1024 if (get_frame_pc (thisframe))
1025 {
1026 CORE_ADDR saved_pc, sig_pc;
1027
1028 saved_pc = s390_frame_saved_pc_nofix (thisframe);
1029 if (saved_pc)
1030 {
1031 if ((sigreturn =
1032 s390_is_sigreturn (saved_pc, thisframe, &sregs, &sig_pc)))
1033 saved_pc = sig_pc;
1034 s390_get_frame_info (s390_sniff_pc_function_start
1035 (saved_pc, NULL), &prev_fextra_info, NULL,
1036 1);
1037 }
1038 }
1039 if (sigreturn)
1040 {
1041 /* read sigregs,regs.gprs[11 or 15] */
1042 prev_fp = read_memory_integer (sregs +
1043 REGISTER_BYTE (S390_GP0_REGNUM +
1044 (prev_fextra_info.
1045 frame_pointer_saved_pc
1046 ? 11 : 15)),
1047 S390_GPR_SIZE);
1048 thisframe->extra_info->sigcontext = sregs;
1049 }
1050 else
1051 {
1052 if (get_frame_saved_regs (thisframe))
1053 {
1054 int regno;
1055
1056 if (prev_fextra_info.frame_pointer_saved_pc
1057 && get_frame_saved_regs (thisframe)[S390_FRAME_REGNUM])
1058 regno = S390_FRAME_REGNUM;
1059 else
1060 regno = S390_SP_REGNUM;
1061
1062 if (get_frame_saved_regs (thisframe)[regno])
1063 {
1064 /* The SP's entry of `saved_regs' is special. */
1065 if (regno == S390_SP_REGNUM)
1066 prev_fp = get_frame_saved_regs (thisframe)[regno];
1067 else
1068 prev_fp =
1069 read_memory_integer (get_frame_saved_regs (thisframe)[regno],
1070 S390_GPR_SIZE);
1071 }
1072 }
1073 }
1074 }
1075 return ADDR_BITS_REMOVE (prev_fp);
1076}
1077
1078/*
1079 Whether struct frame_extra_info is actually needed I'll have to figure
1080 out as our frames are similar to rs6000 there is a possibility
1081 i386 dosen't need it. */
1082
1083
1084
1085/* a given return value in `regbuf' with a type `valtype', extract and copy its
1086 value into `valbuf' */
1087void
1088s390_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
1089{
1090 /* floats and doubles are returned in fpr0. fpr's have a size of 8 bytes.
1091 We need to truncate the return value into float size (4 byte) if
1092 necessary. */
1093 int len = TYPE_LENGTH (valtype);
1094
1095 if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
1096 memcpy (valbuf, &regbuf[REGISTER_BYTE (S390_FP0_REGNUM)], len);
1097 else
1098 {
1099 int offset = 0;
1100 /* return value is copied starting from r2. */
1101 if (TYPE_LENGTH (valtype) < S390_GPR_SIZE)
1102 offset = S390_GPR_SIZE - TYPE_LENGTH (valtype);
1103 memcpy (valbuf,
1104 regbuf + REGISTER_BYTE (S390_GP0_REGNUM + 2) + offset,
1105 TYPE_LENGTH (valtype));
1106 }
1107}
1108
1109
1110static char *
1111s390_promote_integer_argument (struct type *valtype, char *valbuf,
1112 char *reg_buff, int *arglen)
1113{
1114 char *value = valbuf;
1115 int len = TYPE_LENGTH (valtype);
1116
1117 if (len < S390_GPR_SIZE)
1118 {
1119 /* We need to upgrade this value to a register to pass it correctly */
1120 int idx, diff = S390_GPR_SIZE - len, negative =
1121 (!TYPE_UNSIGNED (valtype) && value[0] & 0x80);
1122 for (idx = 0; idx < S390_GPR_SIZE; idx++)
1123 {
1124 reg_buff[idx] = (idx < diff ? (negative ? 0xff : 0x0) :
1125 value[idx - diff]);
1126 }
1127 value = reg_buff;
1128 *arglen = S390_GPR_SIZE;
1129 }
1130 else
1131 {
1132 if (len & (S390_GPR_SIZE - 1))
1133 {
1134 fprintf_unfiltered (gdb_stderr,
1135 "s390_promote_integer_argument detected an argument not "
1136 "a multiple of S390_GPR_SIZE & greater than S390_GPR_SIZE "
1137 "we might not deal with this correctly.\n");
1138 }
1139 *arglen = len;
1140 }
1141
1142 return (value);
1143}
1144
1145void
1146s390_store_return_value (struct type *valtype, char *valbuf)
1147{
1148 int arglen;
1149 char *reg_buff = alloca (max (S390_FPR_SIZE, REGISTER_SIZE)), *value;
1150
1151 if (TYPE_CODE (valtype) == TYPE_CODE_FLT)
1152 {
1153 if (TYPE_LENGTH (valtype) == 4
1154 || TYPE_LENGTH (valtype) == 8)
1155 deprecated_write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM),
1156 valbuf, TYPE_LENGTH (valtype));
1157 else
1158 error ("GDB is unable to return `long double' values "
1159 "on this architecture.");
1160 }
1161 else
1162 {
1163 value =
1164 s390_promote_integer_argument (valtype, valbuf, reg_buff, &arglen);
1165 /* Everything else is returned in GPR2 and up. */
1166 deprecated_write_register_bytes (REGISTER_BYTE (S390_GP0_REGNUM + 2),
1167 value, arglen);
1168 }
1169}
1170static int
1171gdb_print_insn_s390 (bfd_vma memaddr, disassemble_info * info)
1172{
1173 bfd_byte instrbuff[S390_MAX_INSTR_SIZE];
1174 int instrlen, cnt;
1175
1176 instrlen = s390_readinstruction (instrbuff, (CORE_ADDR) memaddr, info);
1177 if (instrlen < 0)
1178 {
1179 (*info->memory_error_func) (instrlen, memaddr, info);
1180 return -1;
1181 }
1182 for (cnt = 0; cnt < instrlen; cnt++)
1183 info->fprintf_func (info->stream, "%02X ", instrbuff[cnt]);
1184 for (cnt = instrlen; cnt < S390_MAX_INSTR_SIZE; cnt++)
1185 info->fprintf_func (info->stream, " ");
1186 instrlen = print_insn_s390 (memaddr, info);
1187 return instrlen;
1188}
1189
1190
1191
1192/* Not the most efficent code in the world */
1193int
1194s390_fp_regnum (void)
1195{
1196 int regno = S390_SP_REGNUM;
1197 struct frame_extra_info fextra_info;
1198
1199 CORE_ADDR pc = ADDR_BITS_REMOVE (read_register (S390_PC_REGNUM));
1200
1201 s390_get_frame_info (s390_sniff_pc_function_start (pc, NULL), &fextra_info,
1202 NULL, 1);
1203 if (fextra_info.frame_pointer_saved_pc)
1204 regno = S390_FRAME_REGNUM;
1205 return regno;
1206}
1207
1208CORE_ADDR
1209s390_read_fp (void)
1210{
1211 return read_register (s390_fp_regnum ());
1212}
1213
1214
1215static void
1216s390_pop_frame_regular (struct frame_info *frame)
1217{
1218 int regnum;
1219
1220 write_register (S390_PC_REGNUM, FRAME_SAVED_PC (frame));
1221
1222 /* Restore any saved registers. */
1223 if (get_frame_saved_regs (frame))
1224 {
1225 for (regnum = 0; regnum < NUM_REGS; regnum++)
1226 if (get_frame_saved_regs (frame)[regnum] != 0)
1227 {
1228 ULONGEST value;
1229
1230 value = read_memory_unsigned_integer (get_frame_saved_regs (frame)[regnum],
1231 REGISTER_RAW_SIZE (regnum));
1232 write_register (regnum, value);
1233 }
1234
1235 /* Actually cut back the stack. Remember that the SP's element of
1236 saved_regs is the old SP itself, not the address at which it is
1237 saved. */
1238 write_register (S390_SP_REGNUM, get_frame_saved_regs (frame)[S390_SP_REGNUM]);
1239 }
1240
1241 /* Throw away any cached frame information. */
1242 flush_cached_frames ();
1243}
1244
1245
1246/* Destroy the innermost (Top-Of-Stack) stack frame, restoring the
1247 machine state that was in effect before the frame was created.
1248 Used in the contexts of the "return" command, and of
1249 target function calls from the debugger. */
1250void
1251s390_pop_frame (void)
1252{
1253 /* This function checks for and handles generic dummy frames, and
1254 calls back to our function for ordinary frames. */
1255 generic_pop_current_frame (s390_pop_frame_regular);
1256}
1257
1258
1259/* Return non-zero if TYPE is an integer-like type, zero otherwise.
1260 "Integer-like" types are those that should be passed the way
1261 integers are: integers, enums, ranges, characters, and booleans. */
1262static int
1263is_integer_like (struct type *type)
1264{
1265 enum type_code code = TYPE_CODE (type);
1266
1267 return (code == TYPE_CODE_INT
1268 || code == TYPE_CODE_ENUM
1269 || code == TYPE_CODE_RANGE
1270 || code == TYPE_CODE_CHAR
1271 || code == TYPE_CODE_BOOL);
1272}
1273
1274
1275/* Return non-zero if TYPE is a pointer-like type, zero otherwise.
1276 "Pointer-like" types are those that should be passed the way
1277 pointers are: pointers and references. */
1278static int
1279is_pointer_like (struct type *type)
1280{
1281 enum type_code code = TYPE_CODE (type);
1282
1283 return (code == TYPE_CODE_PTR
1284 || code == TYPE_CODE_REF);
1285}
1286
1287
1288/* Return non-zero if TYPE is a `float singleton' or `double
1289 singleton', zero otherwise.
1290
1291 A `T singleton' is a struct type with one member, whose type is
1292 either T or a `T singleton'. So, the following are all float
1293 singletons:
1294
1295 struct { float x };
1296 struct { struct { float x; } x; };
1297 struct { struct { struct { float x; } x; } x; };
1298
1299 ... and so on.
1300
1301 WHY THE HECK DO WE CARE ABOUT THIS??? Well, it turns out that GCC
1302 passes all float singletons and double singletons as if they were
1303 simply floats or doubles. This is *not* what the ABI says it
1304 should do. */
1305static int
1306is_float_singleton (struct type *type)
1307{
1308 return (TYPE_CODE (type) == TYPE_CODE_STRUCT
1309 && TYPE_NFIELDS (type) == 1
1310 && (TYPE_CODE (TYPE_FIELD_TYPE (type, 0)) == TYPE_CODE_FLT
1311 || is_float_singleton (TYPE_FIELD_TYPE (type, 0))));
1312}
1313
1314
1315/* Return non-zero if TYPE is a struct-like type, zero otherwise.
1316 "Struct-like" types are those that should be passed as structs are:
1317 structs and unions.
1318
1319 As an odd quirk, not mentioned in the ABI, GCC passes float and
1320 double singletons as if they were a plain float, double, etc. (The
1321 corresponding union types are handled normally.) So we exclude
1322 those types here. *shrug* */
1323static int
1324is_struct_like (struct type *type)
1325{
1326 enum type_code code = TYPE_CODE (type);
1327
1328 return (code == TYPE_CODE_UNION
1329 || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type)));
1330}
1331
1332
1333/* Return non-zero if TYPE is a float-like type, zero otherwise.
1334 "Float-like" types are those that should be passed as
1335 floating-point values are.
1336
1337 You'd think this would just be floats, doubles, long doubles, etc.
1338 But as an odd quirk, not mentioned in the ABI, GCC passes float and
1339 double singletons as if they were a plain float, double, etc. (The
1340 corresponding union types are handled normally.) So we exclude
1341 those types here. *shrug* */
1342static int
1343is_float_like (struct type *type)
1344{
1345 return (TYPE_CODE (type) == TYPE_CODE_FLT
1346 || is_float_singleton (type));
1347}
1348
1349
1350/* Return non-zero if TYPE is considered a `DOUBLE_OR_FLOAT', as
1351 defined by the parameter passing conventions described in the
1352 "GNU/Linux for S/390 ELF Application Binary Interface Supplement".
1353 Otherwise, return zero. */
1354static int
1355is_double_or_float (struct type *type)
1356{
1357 return (is_float_like (type)
1358 && (TYPE_LENGTH (type) == 4
1359 || TYPE_LENGTH (type) == 8));
1360}
1361
1362
1363/* Return non-zero if TYPE is considered a `SIMPLE_ARG', as defined by
1364 the parameter passing conventions described in the "GNU/Linux for
1365 S/390 ELF Application Binary Interface Supplement". Return zero
1366 otherwise. */
1367static int
1368is_simple_arg (struct type *type)
1369{
1370 unsigned length = TYPE_LENGTH (type);
1371
1372 /* This is almost a direct translation of the ABI's language, except
1373 that we have to exclude 8-byte structs; those are DOUBLE_ARGs. */
1374 return ((is_integer_like (type) && length <= 4)
1375 || is_pointer_like (type)
1376 || (is_struct_like (type) && length != 8)
1377 || (is_float_like (type) && length == 16));
1378}
1379
1380
1381/* Return non-zero if TYPE should be passed as a pointer to a copy,
1382 zero otherwise. TYPE must be a SIMPLE_ARG, as recognized by
1383 `is_simple_arg'. */
1384static int
1385pass_by_copy_ref (struct type *type)
1386{
1387 unsigned length = TYPE_LENGTH (type);
1388
1389 return ((is_struct_like (type) && length != 1 && length != 2 && length != 4)
1390 || (is_float_like (type) && length == 16));
1391}
1392
1393
1394/* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full
1395 word as required for the ABI. */
1396static LONGEST
1397extend_simple_arg (struct value *arg)
1398{
1399 struct type *type = VALUE_TYPE (arg);
1400
1401 /* Even structs get passed in the least significant bits of the
1402 register / memory word. It's not really right to extract them as
1403 an integer, but it does take care of the extension. */
1404 if (TYPE_UNSIGNED (type))
1405 return extract_unsigned_integer (VALUE_CONTENTS (arg),
1406 TYPE_LENGTH (type));
1407 else
1408 return extract_signed_integer (VALUE_CONTENTS (arg),
1409 TYPE_LENGTH (type));
1410}
1411
1412
1413/* Return non-zero if TYPE is a `DOUBLE_ARG', as defined by the
1414 parameter passing conventions described in the "GNU/Linux for S/390
1415 ELF Application Binary Interface Supplement". Return zero
1416 otherwise. */
1417static int
1418is_double_arg (struct type *type)
1419{
1420 unsigned length = TYPE_LENGTH (type);
1421
1422 return ((is_integer_like (type)
1423 || is_struct_like (type))
1424 && length == 8);
1425}
1426
1427
1428/* Round ADDR up to the next N-byte boundary. N must be a power of
1429 two. */
1430static CORE_ADDR
1431round_up (CORE_ADDR addr, int n)
1432{
1433 /* Check that N is really a power of two. */
1434 gdb_assert (n && (n & (n-1)) == 0);
1435 return ((addr + n - 1) & -n);
1436}
1437
1438
1439/* Round ADDR down to the next N-byte boundary. N must be a power of
1440 two. */
1441static CORE_ADDR
1442round_down (CORE_ADDR addr, int n)
1443{
1444 /* Check that N is really a power of two. */
1445 gdb_assert (n && (n & (n-1)) == 0);
1446 return (addr & -n);
1447}
1448
1449
1450/* Return the alignment required by TYPE. */
1451static int
1452alignment_of (struct type *type)
1453{
1454 int alignment;
1455
1456 if (is_integer_like (type)
1457 || is_pointer_like (type)
1458 || TYPE_CODE (type) == TYPE_CODE_FLT)
1459 alignment = TYPE_LENGTH (type);
1460 else if (TYPE_CODE (type) == TYPE_CODE_STRUCT
1461 || TYPE_CODE (type) == TYPE_CODE_UNION)
1462 {
1463 int i;
1464
1465 alignment = 1;
1466 for (i = 0; i < TYPE_NFIELDS (type); i++)
1467 {
1468 int field_alignment = alignment_of (TYPE_FIELD_TYPE (type, i));
1469
1470 if (field_alignment > alignment)
1471 alignment = field_alignment;
1472 }
1473 }
1474 else
1475 alignment = 1;
1476
1477 /* Check that everything we ever return is a power of two. Lots of
1478 code doesn't want to deal with aligning things to arbitrary
1479 boundaries. */
1480 gdb_assert ((alignment & (alignment - 1)) == 0);
1481
1482 return alignment;
1483}
1484
1485
1486/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in
1487 place to be passed to a function, as specified by the "GNU/Linux
1488 for S/390 ELF Application Binary Interface Supplement".
1489
1490 SP is the current stack pointer. We must put arguments, links,
1491 padding, etc. whereever they belong, and return the new stack
1492 pointer value.
1493
1494 If STRUCT_RETURN is non-zero, then the function we're calling is
1495 going to return a structure by value; STRUCT_ADDR is the address of
1496 a block we've allocated for it on the stack.
1497
1498 Our caller has taken care of any type promotions needed to satisfy
1499 prototypes or the old K&R argument-passing rules. */
1500CORE_ADDR
1501s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
1502 int struct_return, CORE_ADDR struct_addr)
1503{
1504 int i;
1505 int pointer_size = (TARGET_PTR_BIT / TARGET_CHAR_BIT);
1506
1507 /* The number of arguments passed by reference-to-copy. */
1508 int num_copies;
1509
1510 /* If the i'th argument is passed as a reference to a copy, then
1511 copy_addr[i] is the address of the copy we made. */
1512 CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
1513
1514 /* Build the reference-to-copy area. */
1515 num_copies = 0;
1516 for (i = 0; i < nargs; i++)
1517 {
1518 struct value *arg = args[i];
1519 struct type *type = VALUE_TYPE (arg);
1520 unsigned length = TYPE_LENGTH (type);
1521
1522 if (is_simple_arg (type)
1523 && pass_by_copy_ref (type))
1524 {
1525 sp -= length;
1526 sp = round_down (sp, alignment_of (type));
1527 write_memory (sp, VALUE_CONTENTS (arg), length);
1528 copy_addr[i] = sp;
1529 num_copies++;
1530 }
1531 }
1532
1533 /* Reserve space for the parameter area. As a conservative
1534 simplification, we assume that everything will be passed on the
1535 stack. */
1536 {
1537 int i;
1538
1539 for (i = 0; i < nargs; i++)
1540 {
1541 struct value *arg = args[i];
1542 struct type *type = VALUE_TYPE (arg);
1543 int length = TYPE_LENGTH (type);
1544
1545 sp = round_down (sp, alignment_of (type));
1546
1547 /* SIMPLE_ARG values get extended to 32 bits. Assume every
1548 argument is. */
1549 if (length < 4) length = 4;
1550 sp -= length;
1551 }
1552 }
1553
1554 /* Include space for any reference-to-copy pointers. */
1555 sp = round_down (sp, pointer_size);
1556 sp -= num_copies * pointer_size;
1557
1558 /* After all that, make sure it's still aligned on an eight-byte
1559 boundary. */
1560 sp = round_down (sp, 8);
1561
1562 /* Finally, place the actual parameters, working from SP towards
1563 higher addresses. The code above is supposed to reserve enough
1564 space for this. */
1565 {
1566 int fr = 0;
1567 int gr = 2;
1568 CORE_ADDR starg = sp;
1569
1570 for (i = 0; i < nargs; i++)
1571 {
1572 struct value *arg = args[i];
1573 struct type *type = VALUE_TYPE (arg);
1574
1575 if (is_double_or_float (type)
1576 && fr <= 2)
1577 {
1578 /* When we store a single-precision value in an FP register,
1579 it occupies the leftmost bits. */
1580 deprecated_write_register_bytes (REGISTER_BYTE (S390_FP0_REGNUM + fr),
1581 VALUE_CONTENTS (arg),
1582 TYPE_LENGTH (type));
1583 fr += 2;
1584 }
1585 else if (is_simple_arg (type)
1586 && gr <= 6)
1587 {
1588 /* Do we need to pass a pointer to our copy of this
1589 argument? */
1590 if (pass_by_copy_ref (type))
1591 write_register (S390_GP0_REGNUM + gr, copy_addr[i]);
1592 else
1593 write_register (S390_GP0_REGNUM + gr, extend_simple_arg (arg));
1594
1595 gr++;
1596 }
1597 else if (is_double_arg (type)
1598 && gr <= 5)
1599 {
1600 deprecated_write_register_gen (S390_GP0_REGNUM + gr,
1601 VALUE_CONTENTS (arg));
1602 deprecated_write_register_gen (S390_GP0_REGNUM + gr + 1,
1603 VALUE_CONTENTS (arg) + 4);
1604 gr += 2;
1605 }
1606 else
1607 {
1608 /* The `OTHER' case. */
1609 enum type_code code = TYPE_CODE (type);
1610 unsigned length = TYPE_LENGTH (type);
1611
1612 /* If we skipped r6 because we couldn't fit a DOUBLE_ARG
1613 in it, then don't go back and use it again later. */
1614 if (is_double_arg (type) && gr == 6)
1615 gr = 7;
1616
1617 if (is_simple_arg (type))
1618 {
1619 /* Simple args are always either extended to 32 bits,
1620 or pointers. */
1621 starg = round_up (starg, 4);
1622
1623 /* Do we need to pass a pointer to our copy of this
1624 argument? */
1625 if (pass_by_copy_ref (type))
1626 write_memory_signed_integer (starg, pointer_size,
1627 copy_addr[i]);
1628 else
1629 /* Simple args are always extended to 32 bits. */
1630 write_memory_signed_integer (starg, 4,
1631 extend_simple_arg (arg));
1632 starg += 4;
1633 }
1634 else
1635 {
1636 /* You'd think we should say:
1637 starg = round_up (starg, alignment_of (type));
1638 Unfortunately, GCC seems to simply align the stack on
1639 a four-byte boundary, even when passing doubles. */
1640 starg = round_up (starg, 4);
1641 write_memory (starg, VALUE_CONTENTS (arg), length);
1642 starg += length;
1643 }
1644 }
1645 }
1646 }
1647
1648 /* Allocate the standard frame areas: the register save area, the
1649 word reserved for the compiler (which seems kind of meaningless),
1650 and the back chain pointer. */
1651 sp -= 96;
1652
1653 /* Write the back chain pointer into the first word of the stack
1654 frame. This will help us get backtraces from within functions
1655 called from GDB. */
1656 write_memory_unsigned_integer (sp, (TARGET_PTR_BIT / TARGET_CHAR_BIT),
1657 read_fp ());
1658
1659 return sp;
1660}
1661
1662
1663static int
1664s390_use_struct_convention (int gcc_p, struct type *value_type)
1665{
1666 enum type_code code = TYPE_CODE (value_type);
1667
1668 return (code == TYPE_CODE_STRUCT
1669 || code == TYPE_CODE_UNION);
1670}
1671
1672
1673/* Return the GDB type object for the "standard" data type
1674 of data in register N. */
1675struct type *
1676s390_register_virtual_type (int regno)
1677{
1678 if (S390_FP0_REGNUM <= regno && regno < S390_FP0_REGNUM + S390_NUM_FPRS)
1679 return builtin_type_double;
1680 else
1681 return builtin_type_int;
1682}
1683
1684
1685struct type *
1686s390x_register_virtual_type (int regno)
1687{
1688 return (regno == S390_FPC_REGNUM) ||
1689 (regno >= S390_FIRST_ACR && regno <= S390_LAST_ACR) ? builtin_type_int :
1690 (regno >= S390_FP0_REGNUM) ? builtin_type_double : builtin_type_long;
1691}
1692
1693
1694
1695void
1696s390_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
1697{
1698 write_register (S390_GP0_REGNUM + 2, addr);
1699}
1700
1701
1702
1703const static unsigned char *
1704s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
1705{
1706 static unsigned char breakpoint[] = { 0x0, 0x1 };
1707
1708 *lenptr = sizeof (breakpoint);
1709 return breakpoint;
1710}
1711
1712/* Advance PC across any function entry prologue instructions to reach some
1713 "real" code. */
1714CORE_ADDR
1715s390_skip_prologue (CORE_ADDR pc)
1716{
1717 struct frame_extra_info fextra_info;
1718
1719 s390_get_frame_info (pc, &fextra_info, NULL, 1);
1720 return fextra_info.skip_prologue_function_start;
1721}
1722
1723/* Immediately after a function call, return the saved pc.
1724 Can't go through the frames for this because on some machines
1725 the new frame is not set up until the new function executes
1726 some instructions. */
1727CORE_ADDR
1728s390_saved_pc_after_call (struct frame_info *frame)
1729{
1730 return ADDR_BITS_REMOVE (read_register (S390_RETADDR_REGNUM));
1731}
1732
1733static CORE_ADDR
1734s390_addr_bits_remove (CORE_ADDR addr)
1735{
1736 return (addr) & 0x7fffffff;
1737}
1738
1739
1740static CORE_ADDR
1741s390_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
1742{
1743 write_register (S390_RETADDR_REGNUM, CALL_DUMMY_ADDRESS ());
1744 return sp;
1745}
1746
1747struct gdbarch *
1748s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1749{
1750 static LONGEST s390_call_dummy_words[] = { 0 };
1751 struct gdbarch *gdbarch;
1752 struct gdbarch_tdep *tdep;
1753 int elf_flags;
1754
1755 /* First see if there is already a gdbarch that can satisfy the request. */
1756 arches = gdbarch_list_lookup_by_info (arches, &info);
1757 if (arches != NULL)
1758 return arches->gdbarch;
1759
1760 /* None found: is the request for a s390 architecture? */
1761 if (info.bfd_arch_info->arch != bfd_arch_s390)
1762 return NULL; /* No; then it's not for us. */
1763
1764 /* Yes: create a new gdbarch for the specified machine type. */
1765 gdbarch = gdbarch_alloc (&info, NULL);
1766
1767 /* NOTE: cagney/2002-12-06: This can be deleted when this arch is
1768 ready to unwind the PC first (see frame.c:get_prev_frame()). */
1769 set_gdbarch_deprecated_init_frame_pc (gdbarch, init_frame_pc_default);
1770
1771 set_gdbarch_believe_pcc_promotion (gdbarch, 0);
1772 set_gdbarch_char_signed (gdbarch, 0);
1773
1774 set_gdbarch_frame_args_skip (gdbarch, 0);
1775 set_gdbarch_frame_args_address (gdbarch, s390_frame_args_address);
1776 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1777 set_gdbarch_frame_init_saved_regs (gdbarch, s390_frame_init_saved_regs);
1778 set_gdbarch_frame_locals_address (gdbarch, s390_frame_args_address);
1779 /* We can't do this */
1780 set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown);
1781 set_gdbarch_store_struct_return (gdbarch, s390_store_struct_return);
1782 set_gdbarch_deprecated_extract_return_value (gdbarch, s390_extract_return_value);
1783 set_gdbarch_deprecated_store_return_value (gdbarch, s390_store_return_value);
1784 /* Amount PC must be decremented by after a breakpoint.
1785 This is often the number of bytes in BREAKPOINT
1786 but not always. */
1787 set_gdbarch_decr_pc_after_break (gdbarch, 2);
1788 set_gdbarch_pop_frame (gdbarch, s390_pop_frame);
1789 /* Stack grows downward. */
1790 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1791 /* Offset from address of function to start of its code.
1792 Zero on most machines. */
1793 set_gdbarch_function_start_offset (gdbarch, 0);
1794 set_gdbarch_max_register_raw_size (gdbarch, 8);
1795 set_gdbarch_max_register_virtual_size (gdbarch, 8);
1796 set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc);
1797 set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue);
1798 set_gdbarch_init_extra_frame_info (gdbarch, s390_init_extra_frame_info);
1799 set_gdbarch_deprecated_init_frame_pc_first (gdbarch, s390_init_frame_pc_first);
1800 set_gdbarch_read_fp (gdbarch, s390_read_fp);
1801 /* This function that tells us whether the function invocation represented
1802 by FI does not have a frame on the stack associated with it. If it
1803 does not, FRAMELESS is set to 1, else 0. */
1804 set_gdbarch_frameless_function_invocation (gdbarch,
1805 s390_frameless_function_invocation);
1806 /* Return saved PC from a frame */
1807 set_gdbarch_frame_saved_pc (gdbarch, s390_frame_saved_pc);
1808 /* FRAME_CHAIN takes a frame's nominal address
1809 and produces the frame's chain-pointer. */
1810 set_gdbarch_frame_chain (gdbarch, s390_frame_chain);
1811 set_gdbarch_saved_pc_after_call (gdbarch, s390_saved_pc_after_call);
1812 set_gdbarch_register_byte (gdbarch, s390_register_byte);
1813 set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM);
1814 set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM);
1815 set_gdbarch_fp_regnum (gdbarch, S390_FP_REGNUM);
1816 set_gdbarch_fp0_regnum (gdbarch, S390_FP0_REGNUM);
1817 set_gdbarch_num_regs (gdbarch, S390_NUM_REGS);
1818 set_gdbarch_cannot_fetch_register (gdbarch, s390_cannot_fetch_register);
1819 set_gdbarch_cannot_store_register (gdbarch, s390_cannot_fetch_register);
1820 set_gdbarch_use_struct_convention (gdbarch, s390_use_struct_convention);
1821 set_gdbarch_register_name (gdbarch, s390_register_name);
1822 set_gdbarch_stab_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1823 set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1824 set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_stab_reg_to_regnum);
1825 set_gdbarch_deprecated_extract_struct_value_address
1826 (gdbarch, generic_cannot_extract_struct_value_address);
1827
1828 /* Parameters for inferior function calls. */
1829 set_gdbarch_call_dummy_p (gdbarch, 1);
1830 set_gdbarch_call_dummy_length (gdbarch, 0);
1831 set_gdbarch_call_dummy_address (gdbarch, entry_point_address);
1832 set_gdbarch_call_dummy_start_offset (gdbarch, 0);
1833 set_gdbarch_deprecated_pc_in_call_dummy (gdbarch, deprecated_pc_in_call_dummy_at_entry_point);
1834 set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame);
1835 set_gdbarch_push_arguments (gdbarch, s390_push_arguments);
1836 set_gdbarch_save_dummy_frame_tos (gdbarch, generic_save_dummy_frame_tos);
1837 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1838 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0);
1839 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1840 set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy);
1841 set_gdbarch_push_return_address (gdbarch, s390_push_return_address);
1842 set_gdbarch_sizeof_call_dummy_words (gdbarch,
1843 sizeof (s390_call_dummy_words));
1844 set_gdbarch_call_dummy_words (gdbarch, s390_call_dummy_words);
1845
1846 switch (info.bfd_arch_info->mach)
1847 {
1848 case bfd_mach_s390_31:
1849 set_gdbarch_register_size (gdbarch, 4);
1850 set_gdbarch_register_raw_size (gdbarch, s390_register_raw_size);
1851 set_gdbarch_register_virtual_size (gdbarch, s390_register_raw_size);
1852 set_gdbarch_register_virtual_type (gdbarch, s390_register_virtual_type);
1853
1854 set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove);
1855 set_gdbarch_register_bytes (gdbarch, S390_REGISTER_BYTES);
1856 break;
1857 case bfd_mach_s390_64:
1858 set_gdbarch_register_size (gdbarch, 8);
1859 set_gdbarch_register_raw_size (gdbarch, s390x_register_raw_size);
1860 set_gdbarch_register_virtual_size (gdbarch, s390x_register_raw_size);
1861 set_gdbarch_register_virtual_type (gdbarch,
1862 s390x_register_virtual_type);
1863
1864 set_gdbarch_long_bit (gdbarch, 64);
1865 set_gdbarch_long_long_bit (gdbarch, 64);
1866 set_gdbarch_ptr_bit (gdbarch, 64);
1867 set_gdbarch_register_bytes (gdbarch, S390X_REGISTER_BYTES);
1868 break;
1869 }
1870
1871 return gdbarch;
1872}
1873
1874
1875
1876void
1877_initialize_s390_tdep (void)
1878{
1879
1880 /* Hook us into the gdbarch mechanism. */
1881 register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init);
1882 if (!tm_print_insn) /* Someone may have already set it */
1883 tm_print_insn = gdb_print_insn_s390;
1884}
1885
1886#endif /* GDBSERVER */
GDB Binutils - Deliverables
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