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5769d3cd | 1 | /* Target-dependent code for GDB, the GNU debugger. |
ca557f44 | 2 | |
9ab9195f | 3 | Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc. |
ca557f44 | 4 | |
5769d3cd AC |
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 | ||
d0f54f9d | 25 | #include "defs.h" |
5769d3cd AC |
26 | #include "arch-utils.h" |
27 | #include "frame.h" | |
28 | #include "inferior.h" | |
29 | #include "symtab.h" | |
30 | #include "target.h" | |
31 | #include "gdbcore.h" | |
32 | #include "gdbcmd.h" | |
5769d3cd AC |
33 | #include "objfiles.h" |
34 | #include "tm.h" | |
35 | #include "../bfd/bfd.h" | |
36 | #include "floatformat.h" | |
37 | #include "regcache.h" | |
a8c99f38 JB |
38 | #include "trad-frame.h" |
39 | #include "frame-base.h" | |
40 | #include "frame-unwind.h" | |
d0f54f9d JB |
41 | #include "reggroups.h" |
42 | #include "regset.h" | |
fd0407d6 | 43 | #include "value.h" |
78f8b424 | 44 | #include "gdb_assert.h" |
a89aa300 | 45 | #include "dis-asm.h" |
5769d3cd | 46 | |
d0f54f9d | 47 | #include "s390-tdep.h" |
5769d3cd | 48 | |
60e6cc42 | 49 | |
d0f54f9d JB |
50 | /* The tdep structure. */ |
51 | ||
52 | struct gdbarch_tdep | |
5769d3cd | 53 | { |
b0cf273e JB |
54 | /* ABI version. */ |
55 | enum { ABI_LINUX_S390, ABI_LINUX_ZSERIES } abi; | |
56 | ||
d0f54f9d JB |
57 | /* Core file register sets. */ |
58 | const struct regset *gregset; | |
59 | int sizeof_gregset; | |
60 | ||
61 | const struct regset *fpregset; | |
62 | int sizeof_fpregset; | |
63 | }; | |
64 | ||
65 | ||
66 | /* Register information. */ | |
67 | ||
68 | struct s390_register_info | |
69 | { | |
70 | char *name; | |
71 | struct type **type; | |
72 | }; | |
73 | ||
74 | static struct s390_register_info s390_register_info[S390_NUM_TOTAL_REGS] = | |
75 | { | |
76 | /* Program Status Word. */ | |
77 | { "pswm", &builtin_type_long }, | |
78 | { "pswa", &builtin_type_long }, | |
79 | ||
80 | /* General Purpose Registers. */ | |
81 | { "r0", &builtin_type_long }, | |
82 | { "r1", &builtin_type_long }, | |
83 | { "r2", &builtin_type_long }, | |
84 | { "r3", &builtin_type_long }, | |
85 | { "r4", &builtin_type_long }, | |
86 | { "r5", &builtin_type_long }, | |
87 | { "r6", &builtin_type_long }, | |
88 | { "r7", &builtin_type_long }, | |
89 | { "r8", &builtin_type_long }, | |
90 | { "r9", &builtin_type_long }, | |
91 | { "r10", &builtin_type_long }, | |
92 | { "r11", &builtin_type_long }, | |
93 | { "r12", &builtin_type_long }, | |
94 | { "r13", &builtin_type_long }, | |
95 | { "r14", &builtin_type_long }, | |
96 | { "r15", &builtin_type_long }, | |
97 | ||
98 | /* Access Registers. */ | |
99 | { "acr0", &builtin_type_int }, | |
100 | { "acr1", &builtin_type_int }, | |
101 | { "acr2", &builtin_type_int }, | |
102 | { "acr3", &builtin_type_int }, | |
103 | { "acr4", &builtin_type_int }, | |
104 | { "acr5", &builtin_type_int }, | |
105 | { "acr6", &builtin_type_int }, | |
106 | { "acr7", &builtin_type_int }, | |
107 | { "acr8", &builtin_type_int }, | |
108 | { "acr9", &builtin_type_int }, | |
109 | { "acr10", &builtin_type_int }, | |
110 | { "acr11", &builtin_type_int }, | |
111 | { "acr12", &builtin_type_int }, | |
112 | { "acr13", &builtin_type_int }, | |
113 | { "acr14", &builtin_type_int }, | |
114 | { "acr15", &builtin_type_int }, | |
115 | ||
116 | /* Floating Point Control Word. */ | |
117 | { "fpc", &builtin_type_int }, | |
118 | ||
119 | /* Floating Point Registers. */ | |
120 | { "f0", &builtin_type_double }, | |
121 | { "f1", &builtin_type_double }, | |
122 | { "f2", &builtin_type_double }, | |
123 | { "f3", &builtin_type_double }, | |
124 | { "f4", &builtin_type_double }, | |
125 | { "f5", &builtin_type_double }, | |
126 | { "f6", &builtin_type_double }, | |
127 | { "f7", &builtin_type_double }, | |
128 | { "f8", &builtin_type_double }, | |
129 | { "f9", &builtin_type_double }, | |
130 | { "f10", &builtin_type_double }, | |
131 | { "f11", &builtin_type_double }, | |
132 | { "f12", &builtin_type_double }, | |
133 | { "f13", &builtin_type_double }, | |
134 | { "f14", &builtin_type_double }, | |
135 | { "f15", &builtin_type_double }, | |
136 | ||
137 | /* Pseudo registers. */ | |
138 | { "pc", &builtin_type_void_func_ptr }, | |
139 | { "cc", &builtin_type_int }, | |
140 | }; | |
141 | ||
142 | /* Return the name of register REGNUM. */ | |
143 | static const char * | |
144 | s390_register_name (int regnum) | |
145 | { | |
146 | gdb_assert (regnum >= 0 && regnum < S390_NUM_TOTAL_REGS); | |
147 | return s390_register_info[regnum].name; | |
148 | } | |
149 | ||
150 | /* Return the GDB type object for the "standard" data type of data in | |
151 | register REGNUM. */ | |
152 | static struct type * | |
153 | s390_register_type (struct gdbarch *gdbarch, int regnum) | |
154 | { | |
155 | gdb_assert (regnum >= 0 && regnum < S390_NUM_TOTAL_REGS); | |
156 | return *s390_register_info[regnum].type; | |
5769d3cd AC |
157 | } |
158 | ||
d0f54f9d JB |
159 | /* DWARF Register Mapping. */ |
160 | ||
161 | static int s390_dwarf_regmap[] = | |
162 | { | |
163 | /* General Purpose Registers. */ | |
164 | S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM, | |
165 | S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM, | |
166 | S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM, | |
167 | S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM, | |
168 | ||
169 | /* Floating Point Registers. */ | |
170 | S390_F0_REGNUM, S390_F2_REGNUM, S390_F4_REGNUM, S390_F6_REGNUM, | |
171 | S390_F1_REGNUM, S390_F3_REGNUM, S390_F5_REGNUM, S390_F7_REGNUM, | |
172 | S390_F8_REGNUM, S390_F10_REGNUM, S390_F12_REGNUM, S390_F14_REGNUM, | |
173 | S390_F9_REGNUM, S390_F11_REGNUM, S390_F13_REGNUM, S390_F15_REGNUM, | |
174 | ||
175 | /* Control Registers (not mapped). */ | |
176 | -1, -1, -1, -1, -1, -1, -1, -1, | |
177 | -1, -1, -1, -1, -1, -1, -1, -1, | |
178 | ||
179 | /* Access Registers. */ | |
180 | S390_A0_REGNUM, S390_A1_REGNUM, S390_A2_REGNUM, S390_A3_REGNUM, | |
181 | S390_A4_REGNUM, S390_A5_REGNUM, S390_A6_REGNUM, S390_A7_REGNUM, | |
182 | S390_A8_REGNUM, S390_A9_REGNUM, S390_A10_REGNUM, S390_A11_REGNUM, | |
183 | S390_A12_REGNUM, S390_A13_REGNUM, S390_A14_REGNUM, S390_A15_REGNUM, | |
184 | ||
185 | /* Program Status Word. */ | |
186 | S390_PSWM_REGNUM, | |
187 | S390_PSWA_REGNUM | |
188 | }; | |
189 | ||
190 | /* Convert DWARF register number REG to the appropriate register | |
191 | number used by GDB. */ | |
a78f21af | 192 | static int |
d0f54f9d JB |
193 | s390_dwarf_reg_to_regnum (int reg) |
194 | { | |
195 | int regnum = -1; | |
196 | ||
197 | if (reg >= 0 || reg < ARRAY_SIZE (s390_dwarf_regmap)) | |
198 | regnum = s390_dwarf_regmap[reg]; | |
199 | ||
200 | if (regnum == -1) | |
201 | warning ("Unmapped DWARF Register #%d encountered\n", reg); | |
202 | ||
203 | return regnum; | |
204 | } | |
205 | ||
206 | /* Pseudo registers - PC and condition code. */ | |
207 | ||
208 | static void | |
209 | s390_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, | |
210 | int regnum, void *buf) | |
211 | { | |
212 | ULONGEST val; | |
213 | ||
214 | switch (regnum) | |
215 | { | |
216 | case S390_PC_REGNUM: | |
217 | regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &val); | |
218 | store_unsigned_integer (buf, 4, val & 0x7fffffff); | |
219 | break; | |
220 | ||
221 | case S390_CC_REGNUM: | |
222 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val); | |
223 | store_unsigned_integer (buf, 4, (val >> 12) & 3); | |
224 | break; | |
225 | ||
226 | default: | |
227 | internal_error (__FILE__, __LINE__, "invalid regnum"); | |
228 | } | |
229 | } | |
230 | ||
231 | static void | |
232 | s390_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, | |
233 | int regnum, const void *buf) | |
5769d3cd | 234 | { |
d0f54f9d JB |
235 | ULONGEST val, psw; |
236 | ||
237 | switch (regnum) | |
238 | { | |
239 | case S390_PC_REGNUM: | |
240 | val = extract_unsigned_integer (buf, 4); | |
241 | regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &psw); | |
242 | psw = (psw & 0x80000000) | (val & 0x7fffffff); | |
243 | regcache_raw_write_unsigned (regcache, S390_PSWA_REGNUM, psw); | |
244 | break; | |
245 | ||
246 | case S390_CC_REGNUM: | |
247 | val = extract_unsigned_integer (buf, 4); | |
248 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw); | |
249 | psw = (psw & ~((ULONGEST)3 << 12)) | ((val & 3) << 12); | |
250 | regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, psw); | |
251 | break; | |
252 | ||
253 | default: | |
254 | internal_error (__FILE__, __LINE__, "invalid regnum"); | |
255 | } | |
5769d3cd AC |
256 | } |
257 | ||
d0f54f9d JB |
258 | static void |
259 | s390x_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, | |
260 | int regnum, void *buf) | |
261 | { | |
262 | ULONGEST val; | |
263 | ||
264 | switch (regnum) | |
265 | { | |
266 | case S390_PC_REGNUM: | |
267 | regcache_raw_read (regcache, S390_PSWA_REGNUM, buf); | |
268 | break; | |
269 | ||
270 | case S390_CC_REGNUM: | |
271 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val); | |
272 | store_unsigned_integer (buf, 4, (val >> 44) & 3); | |
273 | break; | |
274 | ||
275 | default: | |
276 | internal_error (__FILE__, __LINE__, "invalid regnum"); | |
277 | } | |
278 | } | |
279 | ||
280 | static void | |
281 | s390x_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, | |
282 | int regnum, const void *buf) | |
283 | { | |
284 | ULONGEST val, psw; | |
285 | ||
286 | switch (regnum) | |
287 | { | |
288 | case S390_PC_REGNUM: | |
289 | regcache_raw_write (regcache, S390_PSWA_REGNUM, buf); | |
290 | break; | |
291 | ||
292 | case S390_CC_REGNUM: | |
293 | val = extract_unsigned_integer (buf, 4); | |
294 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw); | |
295 | psw = (psw & ~((ULONGEST)3 << 44)) | ((val & 3) << 44); | |
296 | regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, psw); | |
297 | break; | |
298 | ||
299 | default: | |
300 | internal_error (__FILE__, __LINE__, "invalid regnum"); | |
301 | } | |
302 | } | |
303 | ||
304 | /* 'float' values are stored in the upper half of floating-point | |
305 | registers, even though we are otherwise a big-endian platform. */ | |
306 | ||
a78f21af | 307 | static int |
d0f54f9d | 308 | s390_convert_register_p (int regno, struct type *type) |
5769d3cd | 309 | { |
d0f54f9d JB |
310 | return (regno >= S390_F0_REGNUM && regno <= S390_F15_REGNUM) |
311 | && TYPE_LENGTH (type) < 8; | |
5769d3cd AC |
312 | } |
313 | ||
d0f54f9d JB |
314 | static void |
315 | s390_register_to_value (struct frame_info *frame, int regnum, | |
316 | struct type *valtype, void *out) | |
317 | { | |
318 | char in[8]; | |
319 | int len = TYPE_LENGTH (valtype); | |
320 | gdb_assert (len < 8); | |
321 | ||
322 | get_frame_register (frame, regnum, in); | |
323 | memcpy (out, in, len); | |
324 | } | |
325 | ||
326 | static void | |
327 | s390_value_to_register (struct frame_info *frame, int regnum, | |
328 | struct type *valtype, const void *in) | |
329 | { | |
330 | char out[8]; | |
331 | int len = TYPE_LENGTH (valtype); | |
332 | gdb_assert (len < 8); | |
333 | ||
334 | memset (out, 0, 8); | |
335 | memcpy (out, in, len); | |
336 | put_frame_register (frame, regnum, out); | |
337 | } | |
338 | ||
339 | /* Register groups. */ | |
340 | ||
a78f21af | 341 | static int |
d0f54f9d JB |
342 | s390_register_reggroup_p (struct gdbarch *gdbarch, int regnum, |
343 | struct reggroup *group) | |
344 | { | |
345 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
346 | ||
347 | /* Registers displayed via 'info regs'. */ | |
348 | if (group == general_reggroup) | |
349 | return (regnum >= S390_R0_REGNUM && regnum <= S390_R15_REGNUM) | |
350 | || regnum == S390_PC_REGNUM | |
351 | || regnum == S390_CC_REGNUM; | |
352 | ||
353 | /* Registers displayed via 'info float'. */ | |
354 | if (group == float_reggroup) | |
355 | return (regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM) | |
356 | || regnum == S390_FPC_REGNUM; | |
357 | ||
358 | /* Registers that need to be saved/restored in order to | |
359 | push or pop frames. */ | |
360 | if (group == save_reggroup || group == restore_reggroup) | |
361 | return regnum != S390_PSWM_REGNUM && regnum != S390_PSWA_REGNUM; | |
362 | ||
363 | return default_register_reggroup_p (gdbarch, regnum, group); | |
364 | } | |
365 | ||
366 | ||
367 | /* Core file register sets. */ | |
368 | ||
369 | int s390_regmap_gregset[S390_NUM_REGS] = | |
370 | { | |
371 | /* Program Status Word. */ | |
372 | 0x00, 0x04, | |
373 | /* General Purpose Registers. */ | |
374 | 0x08, 0x0c, 0x10, 0x14, | |
375 | 0x18, 0x1c, 0x20, 0x24, | |
376 | 0x28, 0x2c, 0x30, 0x34, | |
377 | 0x38, 0x3c, 0x40, 0x44, | |
378 | /* Access Registers. */ | |
379 | 0x48, 0x4c, 0x50, 0x54, | |
380 | 0x58, 0x5c, 0x60, 0x64, | |
381 | 0x68, 0x6c, 0x70, 0x74, | |
382 | 0x78, 0x7c, 0x80, 0x84, | |
383 | /* Floating Point Control Word. */ | |
384 | -1, | |
385 | /* Floating Point Registers. */ | |
386 | -1, -1, -1, -1, -1, -1, -1, -1, | |
387 | -1, -1, -1, -1, -1, -1, -1, -1, | |
388 | }; | |
389 | ||
390 | int s390x_regmap_gregset[S390_NUM_REGS] = | |
391 | { | |
392 | 0x00, 0x08, | |
393 | /* General Purpose Registers. */ | |
394 | 0x10, 0x18, 0x20, 0x28, | |
395 | 0x30, 0x38, 0x40, 0x48, | |
396 | 0x50, 0x58, 0x60, 0x68, | |
397 | 0x70, 0x78, 0x80, 0x88, | |
398 | /* Access Registers. */ | |
399 | 0x90, 0x94, 0x98, 0x9c, | |
400 | 0xa0, 0xa4, 0xa8, 0xac, | |
401 | 0xb0, 0xb4, 0xb8, 0xbc, | |
402 | 0xc0, 0xc4, 0xc8, 0xcc, | |
403 | /* Floating Point Control Word. */ | |
404 | -1, | |
405 | /* Floating Point Registers. */ | |
406 | -1, -1, -1, -1, -1, -1, -1, -1, | |
407 | -1, -1, -1, -1, -1, -1, -1, -1, | |
408 | }; | |
409 | ||
410 | int s390_regmap_fpregset[S390_NUM_REGS] = | |
411 | { | |
412 | /* Program Status Word. */ | |
413 | -1, -1, | |
414 | /* General Purpose Registers. */ | |
415 | -1, -1, -1, -1, -1, -1, -1, -1, | |
416 | -1, -1, -1, -1, -1, -1, -1, -1, | |
417 | /* Access Registers. */ | |
418 | -1, -1, -1, -1, -1, -1, -1, -1, | |
419 | -1, -1, -1, -1, -1, -1, -1, -1, | |
420 | /* Floating Point Control Word. */ | |
421 | 0x00, | |
422 | /* Floating Point Registers. */ | |
423 | 0x08, 0x10, 0x18, 0x20, | |
424 | 0x28, 0x30, 0x38, 0x40, | |
425 | 0x48, 0x50, 0x58, 0x60, | |
426 | 0x68, 0x70, 0x78, 0x80, | |
427 | }; | |
428 | ||
429 | /* Supply register REGNUM from the register set REGSET to register cache | |
430 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ | |
431 | static void | |
432 | s390_supply_regset (const struct regset *regset, struct regcache *regcache, | |
433 | int regnum, const void *regs, size_t len) | |
434 | { | |
435 | const int *offset = regset->descr; | |
436 | int i; | |
437 | ||
438 | for (i = 0; i < S390_NUM_REGS; i++) | |
439 | { | |
440 | if ((regnum == i || regnum == -1) && offset[i] != -1) | |
441 | regcache_raw_supply (regcache, i, (const char *)regs + offset[i]); | |
442 | } | |
443 | } | |
444 | ||
445 | static const struct regset s390_gregset = { | |
446 | s390_regmap_gregset, | |
447 | s390_supply_regset | |
448 | }; | |
449 | ||
450 | static const struct regset s390x_gregset = { | |
451 | s390x_regmap_gregset, | |
452 | s390_supply_regset | |
453 | }; | |
454 | ||
455 | static const struct regset s390_fpregset = { | |
456 | s390_regmap_fpregset, | |
457 | s390_supply_regset | |
458 | }; | |
459 | ||
460 | /* Return the appropriate register set for the core section identified | |
461 | by SECT_NAME and SECT_SIZE. */ | |
462 | const struct regset * | |
463 | s390_regset_from_core_section (struct gdbarch *gdbarch, | |
464 | const char *sect_name, size_t sect_size) | |
465 | { | |
466 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
467 | ||
468 | if (strcmp (sect_name, ".reg") == 0 && sect_size == tdep->sizeof_gregset) | |
469 | return tdep->gregset; | |
470 | ||
471 | if (strcmp (sect_name, ".reg2") == 0 && sect_size == tdep->sizeof_fpregset) | |
472 | return tdep->fpregset; | |
473 | ||
474 | return NULL; | |
5769d3cd AC |
475 | } |
476 | ||
d0f54f9d | 477 | |
4bc8c588 JB |
478 | /* Prologue analysis. */ |
479 | ||
480 | /* When we analyze a prologue, we're really doing 'abstract | |
481 | interpretation' or 'pseudo-evaluation': running the function's code | |
482 | in simulation, but using conservative approximations of the values | |
483 | it would have when it actually runs. For example, if our function | |
484 | starts with the instruction: | |
485 | ||
486 | ahi r1, 42 # add halfword immediate 42 to r1 | |
487 | ||
488 | we don't know exactly what value will be in r1 after executing this | |
489 | instruction, but we do know it'll be 42 greater than its original | |
490 | value. | |
491 | ||
492 | If we then see an instruction like: | |
493 | ||
494 | ahi r1, 22 # add halfword immediate 22 to r1 | |
495 | ||
496 | we still don't know what r1's value is, but again, we can say it is | |
497 | now 64 greater than its original value. | |
498 | ||
499 | If the next instruction were: | |
500 | ||
501 | lr r2, r1 # set r2 to r1's value | |
502 | ||
503 | then we can say that r2's value is now the original value of r1 | |
504 | plus 64. And so on. | |
505 | ||
506 | Of course, this can only go so far before it gets unreasonable. If | |
507 | we wanted to be able to say anything about the value of r1 after | |
508 | the instruction: | |
509 | ||
510 | xr r1, r3 # exclusive-or r1 and r3, place result in r1 | |
511 | ||
512 | then things would get pretty complex. But remember, we're just | |
513 | doing a conservative approximation; if exclusive-or instructions | |
514 | aren't relevant to prologues, we can just say r1's value is now | |
515 | 'unknown'. We can ignore things that are too complex, if that loss | |
516 | of information is acceptable for our application. | |
517 | ||
518 | Once you've reached an instruction that you don't know how to | |
519 | simulate, you stop. Now you examine the state of the registers and | |
520 | stack slots you've kept track of. For example: | |
521 | ||
522 | - To see how large your stack frame is, just check the value of sp; | |
523 | if it's the original value of sp minus a constant, then that | |
524 | constant is the stack frame's size. If the sp's value has been | |
525 | marked as 'unknown', then that means the prologue has done | |
526 | something too complex for us to track, and we don't know the | |
527 | frame size. | |
528 | ||
529 | - To see whether we've saved the SP in the current frame's back | |
530 | chain slot, we just check whether the current value of the back | |
531 | chain stack slot is the original value of the sp. | |
532 | ||
533 | Sure, this takes some work. But prologue analyzers aren't | |
534 | quick-and-simple pattern patching to recognize a few fixed prologue | |
535 | forms any more; they're big, hairy functions. Along with inferior | |
536 | function calls, prologue analysis accounts for a substantial | |
537 | portion of the time needed to stabilize a GDB port. So I think | |
538 | it's worthwhile to look for an approach that will be easier to | |
539 | understand and maintain. In the approach used here: | |
540 | ||
541 | - It's easier to see that the analyzer is correct: you just see | |
542 | whether the analyzer properly (albiet conservatively) simulates | |
543 | the effect of each instruction. | |
544 | ||
545 | - It's easier to extend the analyzer: you can add support for new | |
546 | instructions, and know that you haven't broken anything that | |
547 | wasn't already broken before. | |
548 | ||
549 | - It's orthogonal: to gather new information, you don't need to | |
550 | complicate the code for each instruction. As long as your domain | |
551 | of conservative values is already detailed enough to tell you | |
552 | what you need, then all the existing instruction simulations are | |
553 | already gathering the right data for you. | |
554 | ||
555 | A 'struct prologue_value' is a conservative approximation of the | |
556 | real value the register or stack slot will have. */ | |
557 | ||
558 | struct prologue_value { | |
559 | ||
560 | /* What sort of value is this? This determines the interpretation | |
561 | of subsequent fields. */ | |
562 | enum { | |
563 | ||
564 | /* We don't know anything about the value. This is also used for | |
565 | values we could have kept track of, when doing so would have | |
566 | been too complex and we don't want to bother. The bottom of | |
567 | our lattice. */ | |
568 | pv_unknown, | |
569 | ||
570 | /* A known constant. K is its value. */ | |
571 | pv_constant, | |
572 | ||
573 | /* The value that register REG originally had *UPON ENTRY TO THE | |
574 | FUNCTION*, plus K. If K is zero, this means, obviously, just | |
575 | the value REG had upon entry to the function. REG is a GDB | |
576 | register number. Before we start interpreting, we initialize | |
577 | every register R to { pv_register, R, 0 }. */ | |
578 | pv_register, | |
579 | ||
580 | } kind; | |
581 | ||
582 | /* The meanings of the following fields depend on 'kind'; see the | |
583 | comments for the specific 'kind' values. */ | |
584 | int reg; | |
585 | CORE_ADDR k; | |
586 | }; | |
587 | ||
588 | ||
589 | /* Set V to be unknown. */ | |
590 | static void | |
591 | pv_set_to_unknown (struct prologue_value *v) | |
592 | { | |
593 | v->kind = pv_unknown; | |
594 | } | |
595 | ||
596 | ||
597 | /* Set V to the constant K. */ | |
598 | static void | |
599 | pv_set_to_constant (struct prologue_value *v, CORE_ADDR k) | |
600 | { | |
601 | v->kind = pv_constant; | |
602 | v->k = k; | |
603 | } | |
604 | ||
605 | ||
606 | /* Set V to the original value of register REG, plus K. */ | |
607 | static void | |
608 | pv_set_to_register (struct prologue_value *v, int reg, CORE_ADDR k) | |
609 | { | |
610 | v->kind = pv_register; | |
611 | v->reg = reg; | |
612 | v->k = k; | |
613 | } | |
614 | ||
615 | ||
616 | /* If one of *A and *B is a constant, and the other isn't, swap the | |
617 | pointers as necessary to ensure that *B points to the constant. | |
618 | This can reduce the number of cases we need to analyze in the | |
619 | functions below. */ | |
620 | static void | |
621 | pv_constant_last (struct prologue_value **a, | |
622 | struct prologue_value **b) | |
623 | { | |
624 | if ((*a)->kind == pv_constant | |
625 | && (*b)->kind != pv_constant) | |
626 | { | |
627 | struct prologue_value *temp = *a; | |
628 | *a = *b; | |
629 | *b = temp; | |
630 | } | |
631 | } | |
632 | ||
633 | ||
634 | /* Set SUM to the sum of A and B. SUM, A, and B may point to the same | |
635 | 'struct prologue_value' object. */ | |
636 | static void | |
637 | pv_add (struct prologue_value *sum, | |
638 | struct prologue_value *a, | |
639 | struct prologue_value *b) | |
640 | { | |
641 | pv_constant_last (&a, &b); | |
642 | ||
643 | /* We can handle adding constants to registers, and other constants. */ | |
644 | if (b->kind == pv_constant | |
645 | && (a->kind == pv_register | |
646 | || a->kind == pv_constant)) | |
647 | { | |
648 | sum->kind = a->kind; | |
649 | sum->reg = a->reg; /* not meaningful if a is pv_constant, but | |
650 | harmless */ | |
651 | sum->k = a->k + b->k; | |
652 | } | |
653 | ||
654 | /* Anything else we don't know how to add. We don't have a | |
655 | representation for, say, the sum of two registers, or a multiple | |
656 | of a register's value (adding a register to itself). */ | |
657 | else | |
658 | sum->kind = pv_unknown; | |
659 | } | |
660 | ||
661 | ||
662 | /* Add the constant K to V. */ | |
663 | static void | |
664 | pv_add_constant (struct prologue_value *v, CORE_ADDR k) | |
665 | { | |
666 | struct prologue_value pv_k; | |
667 | ||
668 | /* Rather than thinking of all the cases we can and can't handle, | |
669 | we'll just let pv_add take care of that for us. */ | |
670 | pv_set_to_constant (&pv_k, k); | |
671 | pv_add (v, v, &pv_k); | |
672 | } | |
673 | ||
674 | ||
675 | /* Subtract B from A, and put the result in DIFF. | |
676 | ||
677 | This isn't quite the same as negating B and adding it to A, since | |
678 | we don't have a representation for the negation of anything but a | |
679 | constant. For example, we can't negate { pv_register, R1, 10 }, | |
680 | but we do know that { pv_register, R1, 10 } minus { pv_register, | |
681 | R1, 5 } is { pv_constant, <ignored>, 5 }. | |
682 | ||
683 | This means, for example, that we can subtract two stack addresses; | |
684 | they're both relative to the original SP. Since the frame pointer | |
685 | is set based on the SP, its value will be the original SP plus some | |
686 | constant (probably zero), so we can use its value just fine. */ | |
687 | static void | |
688 | pv_subtract (struct prologue_value *diff, | |
689 | struct prologue_value *a, | |
690 | struct prologue_value *b) | |
691 | { | |
692 | pv_constant_last (&a, &b); | |
693 | ||
694 | /* We can subtract a constant from another constant, or from a | |
695 | register. */ | |
696 | if (b->kind == pv_constant | |
697 | && (a->kind == pv_register | |
698 | || a->kind == pv_constant)) | |
699 | { | |
700 | diff->kind = a->kind; | |
701 | diff->reg = a->reg; /* not always meaningful, but harmless */ | |
702 | diff->k = a->k - b->k; | |
703 | } | |
704 | ||
705 | /* We can subtract a register from itself, yielding a constant. */ | |
706 | else if (a->kind == pv_register | |
707 | && b->kind == pv_register | |
708 | && a->reg == b->reg) | |
709 | { | |
710 | diff->kind = pv_constant; | |
711 | diff->k = a->k - b->k; | |
712 | } | |
713 | ||
714 | /* We don't know how to subtract anything else. */ | |
715 | else | |
716 | diff->kind = pv_unknown; | |
717 | } | |
718 | ||
719 | ||
720 | /* Set AND to the logical and of A and B. */ | |
721 | static void | |
722 | pv_logical_and (struct prologue_value *and, | |
723 | struct prologue_value *a, | |
724 | struct prologue_value *b) | |
725 | { | |
726 | pv_constant_last (&a, &b); | |
727 | ||
728 | /* We can 'and' two constants. */ | |
729 | if (a->kind == pv_constant | |
730 | && b->kind == pv_constant) | |
731 | { | |
732 | and->kind = pv_constant; | |
733 | and->k = a->k & b->k; | |
734 | } | |
735 | ||
736 | /* We can 'and' anything with the constant zero. */ | |
737 | else if (b->kind == pv_constant | |
738 | && b->k == 0) | |
739 | { | |
740 | and->kind = pv_constant; | |
741 | and->k = 0; | |
742 | } | |
743 | ||
744 | /* We can 'and' anything with ~0. */ | |
745 | else if (b->kind == pv_constant | |
746 | && b->k == ~ (CORE_ADDR) 0) | |
747 | *and = *a; | |
748 | ||
749 | /* We can 'and' a register with itself. */ | |
750 | else if (a->kind == pv_register | |
751 | && b->kind == pv_register | |
752 | && a->reg == b->reg | |
753 | && a->k == b->k) | |
754 | *and = *a; | |
755 | ||
756 | /* Otherwise, we don't know. */ | |
757 | else | |
758 | pv_set_to_unknown (and); | |
759 | } | |
760 | ||
761 | ||
762 | /* Return non-zero iff A and B are identical expressions. | |
763 | ||
764 | This is not the same as asking if the two values are equal; the | |
765 | result of such a comparison would have to be a pv_boolean, and | |
766 | asking whether two 'unknown' values were equal would give you | |
767 | pv_maybe. Same for comparing, say, { pv_register, R1, 0 } and { | |
768 | pv_register, R2, 0}. Instead, this is asking whether the two | |
769 | representations are the same. */ | |
12bffad7 | 770 | static int |
4bc8c588 JB |
771 | pv_is_identical (struct prologue_value *a, |
772 | struct prologue_value *b) | |
12bffad7 | 773 | { |
4bc8c588 JB |
774 | if (a->kind != b->kind) |
775 | return 0; | |
776 | ||
777 | switch (a->kind) | |
778 | { | |
779 | case pv_unknown: | |
780 | return 1; | |
781 | case pv_constant: | |
782 | return (a->k == b->k); | |
783 | case pv_register: | |
784 | return (a->reg == b->reg && a->k == b->k); | |
785 | default: | |
786 | gdb_assert (0); | |
787 | } | |
12bffad7 JB |
788 | } |
789 | ||
5769d3cd | 790 | |
4bc8c588 JB |
791 | /* Return non-zero if A is the original value of register number R |
792 | plus K, zero otherwise. */ | |
793 | static int | |
794 | pv_is_register (struct prologue_value *a, int r, CORE_ADDR k) | |
795 | { | |
796 | return (a->kind == pv_register | |
797 | && a->reg == r | |
798 | && a->k == k); | |
799 | } | |
5769d3cd | 800 | |
5769d3cd | 801 | |
4bc8c588 JB |
802 | /* A prologue-value-esque boolean type, including "maybe", when we |
803 | can't figure out whether something is true or not. */ | |
804 | enum pv_boolean { | |
805 | pv_maybe, | |
806 | pv_definite_yes, | |
807 | pv_definite_no, | |
808 | }; | |
809 | ||
810 | ||
811 | /* Decide whether a reference to SIZE bytes at ADDR refers exactly to | |
812 | an element of an array. The array starts at ARRAY_ADDR, and has | |
813 | ARRAY_LEN values of ELT_SIZE bytes each. If ADDR definitely does | |
814 | refer to an array element, set *I to the index of the referenced | |
815 | element in the array, and return pv_definite_yes. If it definitely | |
816 | doesn't, return pv_definite_no. If we can't tell, return pv_maybe. | |
817 | ||
818 | If the reference does touch the array, but doesn't fall exactly on | |
819 | an element boundary, or doesn't refer to the whole element, return | |
820 | pv_maybe. */ | |
821 | static enum pv_boolean | |
822 | pv_is_array_ref (struct prologue_value *addr, | |
823 | CORE_ADDR size, | |
824 | struct prologue_value *array_addr, | |
825 | CORE_ADDR array_len, | |
826 | CORE_ADDR elt_size, | |
827 | int *i) | |
828 | { | |
829 | struct prologue_value offset; | |
5769d3cd | 830 | |
4bc8c588 JB |
831 | /* Note that, since ->k is a CORE_ADDR, and CORE_ADDR is unsigned, |
832 | if addr is *before* the start of the array, then this isn't going | |
833 | to be negative... */ | |
834 | pv_subtract (&offset, addr, array_addr); | |
835 | ||
836 | if (offset.kind == pv_constant) | |
837 | { | |
838 | /* This is a rather odd test. We want to know if the SIZE bytes | |
839 | at ADDR don't overlap the array at all, so you'd expect it to | |
840 | be an || expression: "if we're completely before || we're | |
841 | completely after". But with unsigned arithmetic, things are | |
842 | different: since it's a number circle, not a number line, the | |
843 | right values for offset.k are actually one contiguous range. */ | |
844 | if (offset.k <= -size | |
845 | && offset.k >= array_len * elt_size) | |
846 | return pv_definite_no; | |
847 | else if (offset.k % elt_size != 0 | |
848 | || size != elt_size) | |
849 | return pv_maybe; | |
850 | else | |
851 | { | |
852 | *i = offset.k / elt_size; | |
853 | return pv_definite_yes; | |
854 | } | |
855 | } | |
856 | else | |
857 | return pv_maybe; | |
858 | } | |
859 | ||
860 | ||
861 | ||
862 | /* Decoding S/390 instructions. */ | |
863 | ||
864 | /* Named opcode values for the S/390 instructions we recognize. Some | |
865 | instructions have their opcode split across two fields; those are the | |
866 | op1_* and op2_* enums. */ | |
867 | enum | |
868 | { | |
a8c99f38 JB |
869 | op1_lhi = 0xa7, op2_lhi = 0x08, |
870 | op1_lghi = 0xa7, op2_lghi = 0x09, | |
4bc8c588 | 871 | op_lr = 0x18, |
a8c99f38 JB |
872 | op_lgr = 0xb904, |
873 | op_l = 0x58, | |
874 | op1_ly = 0xe3, op2_ly = 0x58, | |
875 | op1_lg = 0xe3, op2_lg = 0x04, | |
876 | op_lm = 0x98, | |
877 | op1_lmy = 0xeb, op2_lmy = 0x98, | |
878 | op1_lmg = 0xeb, op2_lmg = 0x04, | |
4bc8c588 | 879 | op_st = 0x50, |
a8c99f38 | 880 | op1_sty = 0xe3, op2_sty = 0x50, |
4bc8c588 | 881 | op1_stg = 0xe3, op2_stg = 0x24, |
a8c99f38 | 882 | op_std = 0x60, |
4bc8c588 | 883 | op_stm = 0x90, |
a8c99f38 | 884 | op1_stmy = 0xeb, op2_stmy = 0x90, |
4bc8c588 | 885 | op1_stmg = 0xeb, op2_stmg = 0x24, |
a8c99f38 JB |
886 | op1_aghi = 0xa7, op2_aghi = 0x0b, |
887 | op1_ahi = 0xa7, op2_ahi = 0x0a, | |
888 | op_ar = 0x1a, | |
889 | op_agr = 0xb908, | |
890 | op_a = 0x5a, | |
891 | op1_ay = 0xe3, op2_ay = 0x5a, | |
892 | op1_ag = 0xe3, op2_ag = 0x08, | |
893 | op_sr = 0x1b, | |
894 | op_sgr = 0xb909, | |
895 | op_s = 0x5b, | |
896 | op1_sy = 0xe3, op2_sy = 0x5b, | |
897 | op1_sg = 0xe3, op2_sg = 0x09, | |
898 | op_nr = 0x14, | |
899 | op_ngr = 0xb980, | |
900 | op_la = 0x41, | |
901 | op1_lay = 0xe3, op2_lay = 0x71, | |
902 | op1_larl = 0xc0, op2_larl = 0x00, | |
903 | op_basr = 0x0d, | |
904 | op_bas = 0x4d, | |
905 | op_bcr = 0x07, | |
906 | op_bc = 0x0d, | |
907 | op1_bras = 0xa7, op2_bras = 0x05, | |
908 | op1_brasl= 0xc0, op2_brasl= 0x05, | |
909 | op1_brc = 0xa7, op2_brc = 0x04, | |
910 | op1_brcl = 0xc0, op2_brcl = 0x04, | |
4bc8c588 JB |
911 | }; |
912 | ||
913 | ||
a8c99f38 JB |
914 | /* Read a single instruction from address AT. */ |
915 | ||
916 | #define S390_MAX_INSTR_SIZE 6 | |
917 | static int | |
918 | s390_readinstruction (bfd_byte instr[], CORE_ADDR at) | |
919 | { | |
920 | static int s390_instrlen[] = { 2, 4, 4, 6 }; | |
921 | int instrlen; | |
922 | ||
923 | if (read_memory_nobpt (at, &instr[0], 2)) | |
924 | return -1; | |
925 | instrlen = s390_instrlen[instr[0] >> 6]; | |
926 | if (instrlen > 2) | |
927 | { | |
928 | if (read_memory_nobpt (at + 2, &instr[2], instrlen - 2)) | |
929 | return -1; | |
930 | } | |
931 | return instrlen; | |
932 | } | |
933 | ||
934 | ||
4bc8c588 JB |
935 | /* The functions below are for recognizing and decoding S/390 |
936 | instructions of various formats. Each of them checks whether INSN | |
937 | is an instruction of the given format, with the specified opcodes. | |
938 | If it is, it sets the remaining arguments to the values of the | |
939 | instruction's fields, and returns a non-zero value; otherwise, it | |
940 | returns zero. | |
941 | ||
942 | These functions' arguments appear in the order they appear in the | |
943 | instruction, not in the machine-language form. So, opcodes always | |
944 | come first, even though they're sometimes scattered around the | |
945 | instructions. And displacements appear before base and extension | |
946 | registers, as they do in the assembly syntax, not at the end, as | |
947 | they do in the machine language. */ | |
a78f21af | 948 | static int |
4bc8c588 JB |
949 | is_ri (bfd_byte *insn, int op1, int op2, unsigned int *r1, int *i2) |
950 | { | |
951 | if (insn[0] == op1 && (insn[1] & 0xf) == op2) | |
952 | { | |
953 | *r1 = (insn[1] >> 4) & 0xf; | |
954 | /* i2 is a 16-bit signed quantity. */ | |
955 | *i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000; | |
956 | return 1; | |
957 | } | |
958 | else | |
959 | return 0; | |
960 | } | |
8ac0e65a | 961 | |
5769d3cd | 962 | |
4bc8c588 JB |
963 | static int |
964 | is_ril (bfd_byte *insn, int op1, int op2, | |
965 | unsigned int *r1, int *i2) | |
966 | { | |
967 | if (insn[0] == op1 && (insn[1] & 0xf) == op2) | |
968 | { | |
969 | *r1 = (insn[1] >> 4) & 0xf; | |
970 | /* i2 is a signed quantity. If the host 'int' is 32 bits long, | |
971 | no sign extension is necessary, but we don't want to assume | |
972 | that. */ | |
973 | *i2 = (((insn[2] << 24) | |
974 | | (insn[3] << 16) | |
975 | | (insn[4] << 8) | |
976 | | (insn[5])) ^ 0x80000000) - 0x80000000; | |
977 | return 1; | |
978 | } | |
979 | else | |
980 | return 0; | |
981 | } | |
982 | ||
983 | ||
984 | static int | |
985 | is_rr (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) | |
986 | { | |
987 | if (insn[0] == op) | |
988 | { | |
989 | *r1 = (insn[1] >> 4) & 0xf; | |
990 | *r2 = insn[1] & 0xf; | |
991 | return 1; | |
992 | } | |
993 | else | |
994 | return 0; | |
995 | } | |
996 | ||
997 | ||
998 | static int | |
999 | is_rre (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) | |
1000 | { | |
1001 | if (((insn[0] << 8) | insn[1]) == op) | |
1002 | { | |
1003 | /* Yes, insn[3]. insn[2] is unused in RRE format. */ | |
1004 | *r1 = (insn[3] >> 4) & 0xf; | |
1005 | *r2 = insn[3] & 0xf; | |
1006 | return 1; | |
1007 | } | |
1008 | else | |
1009 | return 0; | |
1010 | } | |
1011 | ||
1012 | ||
1013 | static int | |
1014 | is_rs (bfd_byte *insn, int op, | |
1015 | unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2) | |
1016 | { | |
1017 | if (insn[0] == op) | |
1018 | { | |
1019 | *r1 = (insn[1] >> 4) & 0xf; | |
1020 | *r3 = insn[1] & 0xf; | |
1021 | *b2 = (insn[2] >> 4) & 0xf; | |
1022 | *d2 = ((insn[2] & 0xf) << 8) | insn[3]; | |
1023 | return 1; | |
1024 | } | |
1025 | else | |
1026 | return 0; | |
1027 | } | |
1028 | ||
1029 | ||
1030 | static int | |
a8c99f38 | 1031 | is_rsy (bfd_byte *insn, int op1, int op2, |
4bc8c588 JB |
1032 | unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2) |
1033 | { | |
1034 | if (insn[0] == op1 | |
4bc8c588 JB |
1035 | && insn[5] == op2) |
1036 | { | |
1037 | *r1 = (insn[1] >> 4) & 0xf; | |
1038 | *r3 = insn[1] & 0xf; | |
1039 | *b2 = (insn[2] >> 4) & 0xf; | |
a8c99f38 JB |
1040 | /* The 'long displacement' is a 20-bit signed integer. */ |
1041 | *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) | |
1042 | ^ 0x80000) - 0x80000; | |
4bc8c588 JB |
1043 | return 1; |
1044 | } | |
1045 | else | |
1046 | return 0; | |
1047 | } | |
1048 | ||
1049 | ||
1050 | static int | |
1051 | is_rx (bfd_byte *insn, int op, | |
1052 | unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2) | |
1053 | { | |
1054 | if (insn[0] == op) | |
1055 | { | |
1056 | *r1 = (insn[1] >> 4) & 0xf; | |
1057 | *x2 = insn[1] & 0xf; | |
1058 | *b2 = (insn[2] >> 4) & 0xf; | |
1059 | *d2 = ((insn[2] & 0xf) << 8) | insn[3]; | |
1060 | return 1; | |
1061 | } | |
1062 | else | |
1063 | return 0; | |
1064 | } | |
1065 | ||
1066 | ||
1067 | static int | |
a8c99f38 | 1068 | is_rxy (bfd_byte *insn, int op1, int op2, |
4bc8c588 JB |
1069 | unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2) |
1070 | { | |
1071 | if (insn[0] == op1 | |
4bc8c588 JB |
1072 | && insn[5] == op2) |
1073 | { | |
1074 | *r1 = (insn[1] >> 4) & 0xf; | |
1075 | *x2 = insn[1] & 0xf; | |
1076 | *b2 = (insn[2] >> 4) & 0xf; | |
a8c99f38 JB |
1077 | /* The 'long displacement' is a 20-bit signed integer. */ |
1078 | *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) | |
1079 | ^ 0x80000) - 0x80000; | |
4bc8c588 JB |
1080 | return 1; |
1081 | } | |
1082 | else | |
1083 | return 0; | |
1084 | } | |
1085 | ||
1086 | ||
1087 | /* Set ADDR to the effective address for an X-style instruction, like: | |
1088 | ||
1089 | L R1, D2(X2, B2) | |
1090 | ||
a8c99f38 | 1091 | Here, X2 and B2 are registers, and D2 is a signed 20-bit |
4bc8c588 JB |
1092 | constant; the effective address is the sum of all three. If either |
1093 | X2 or B2 are zero, then it doesn't contribute to the sum --- this | |
1094 | means that r0 can't be used as either X2 or B2. | |
1095 | ||
1096 | GPR is an array of general register values, indexed by GPR number, | |
1097 | not GDB register number. */ | |
1098 | static void | |
1099 | compute_x_addr (struct prologue_value *addr, | |
1100 | struct prologue_value *gpr, | |
a8c99f38 | 1101 | int d2, unsigned int x2, unsigned int b2) |
4bc8c588 JB |
1102 | { |
1103 | /* We can't just add stuff directly in addr; it might alias some of | |
1104 | the registers we need to read. */ | |
1105 | struct prologue_value result; | |
1106 | ||
1107 | pv_set_to_constant (&result, d2); | |
1108 | if (x2) | |
1109 | pv_add (&result, &result, &gpr[x2]); | |
1110 | if (b2) | |
1111 | pv_add (&result, &result, &gpr[b2]); | |
1112 | ||
1113 | *addr = result; | |
1114 | } | |
1115 | ||
1116 | ||
1117 | /* The number of GPR and FPR spill slots in an S/390 stack frame. We | |
1118 | track general-purpose registers r2 -- r15, and floating-point | |
1119 | registers f0, f2, f4, and f6. */ | |
1120 | #define S390_NUM_SPILL_SLOTS (14 + 4) | |
d0f54f9d JB |
1121 | #define S390_NUM_GPRS 16 |
1122 | #define S390_NUM_FPRS 16 | |
4bc8c588 | 1123 | |
a8c99f38 JB |
1124 | struct s390_prologue_data { |
1125 | ||
1126 | /* The size of a GPR or FPR. */ | |
1127 | int gpr_size; | |
1128 | int fpr_size; | |
1129 | ||
1130 | /* The general-purpose registers. */ | |
1131 | struct prologue_value gpr[S390_NUM_GPRS]; | |
1132 | ||
1133 | /* The floating-point registers. */ | |
1134 | struct prologue_value fpr[S390_NUM_FPRS]; | |
1135 | ||
1136 | /* The register spill stack slots in the caller's frame --- | |
1137 | general-purpose registers r2 through r15, and floating-point | |
1138 | registers. spill[i] is where gpr i+2 gets spilled; | |
1139 | spill[(14, 15, 16, 17)] is where (f0, f2, f4, f6) get spilled. */ | |
1140 | struct prologue_value spill[S390_NUM_SPILL_SLOTS]; | |
1141 | ||
1142 | /* The value of the back chain slot. This is only valid if the stack | |
1143 | pointer is known to be less than its original value --- that is, | |
1144 | if we have indeed allocated space on the stack. */ | |
1145 | struct prologue_value back_chain; | |
1146 | }; | |
1147 | ||
4bc8c588 JB |
1148 | |
1149 | /* If the SIZE bytes at ADDR are a stack slot we're actually tracking, | |
1150 | return pv_definite_yes and set *STACK to point to the slot. If | |
1151 | we're sure that they are not any of our stack slots, then return | |
1152 | pv_definite_no. Otherwise, return pv_maybe. | |
a8c99f38 JB |
1153 | |
1154 | DATA describes our current state (registers and stack slots). */ | |
4bc8c588 JB |
1155 | static enum pv_boolean |
1156 | s390_on_stack (struct prologue_value *addr, | |
1157 | CORE_ADDR size, | |
a8c99f38 | 1158 | struct s390_prologue_data *data, |
4bc8c588 JB |
1159 | struct prologue_value **stack) |
1160 | { | |
1161 | struct prologue_value gpr_spill_addr; | |
1162 | struct prologue_value fpr_spill_addr; | |
1163 | struct prologue_value back_chain_addr; | |
1164 | int i; | |
1165 | enum pv_boolean b; | |
1166 | ||
1167 | /* Construct the addresses of the spill arrays and the back chain. */ | |
a8c99f38 JB |
1168 | pv_set_to_register (&gpr_spill_addr, S390_SP_REGNUM, 2 * data->gpr_size); |
1169 | pv_set_to_register (&fpr_spill_addr, S390_SP_REGNUM, 16 * data->gpr_size); | |
1170 | back_chain_addr = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; | |
4bc8c588 JB |
1171 | |
1172 | /* We have to check for GPR and FPR references using two separate | |
1173 | calls to pv_is_array_ref, since the GPR and FPR spill slots are | |
1174 | different sizes. (SPILL is an array, but the thing it tracks | |
1175 | isn't really an array.) */ | |
1176 | ||
1177 | /* Was it a reference to the GPR spill array? */ | |
a8c99f38 | 1178 | b = pv_is_array_ref (addr, size, &gpr_spill_addr, 14, data->gpr_size, &i); |
4bc8c588 JB |
1179 | if (b == pv_definite_yes) |
1180 | { | |
a8c99f38 | 1181 | *stack = &data->spill[i]; |
4bc8c588 JB |
1182 | return pv_definite_yes; |
1183 | } | |
1184 | if (b == pv_maybe) | |
1185 | return pv_maybe; | |
1186 | ||
1187 | /* Was it a reference to the FPR spill array? */ | |
a8c99f38 | 1188 | b = pv_is_array_ref (addr, size, &fpr_spill_addr, 4, data->fpr_size, &i); |
4bc8c588 | 1189 | if (b == pv_definite_yes) |
5769d3cd | 1190 | { |
a8c99f38 | 1191 | *stack = &data->spill[14 + i]; |
4bc8c588 | 1192 | return pv_definite_yes; |
5769d3cd | 1193 | } |
4bc8c588 JB |
1194 | if (b == pv_maybe) |
1195 | return pv_maybe; | |
1196 | ||
1197 | /* Was it a reference to the back chain? | |
1198 | This isn't quite right. We ought to check whether we have | |
1199 | actually allocated any new frame at all. */ | |
a8c99f38 | 1200 | b = pv_is_array_ref (addr, size, &back_chain_addr, 1, data->gpr_size, &i); |
4bc8c588 | 1201 | if (b == pv_definite_yes) |
5769d3cd | 1202 | { |
a8c99f38 | 1203 | *stack = &data->back_chain; |
4bc8c588 JB |
1204 | return pv_definite_yes; |
1205 | } | |
1206 | if (b == pv_maybe) | |
1207 | return pv_maybe; | |
1208 | ||
1209 | /* All the above queries returned definite 'no's. */ | |
1210 | return pv_definite_no; | |
1211 | } | |
1212 | ||
1213 | ||
a8c99f38 JB |
1214 | /* Do a SIZE-byte store of VALUE to ADDR. */ |
1215 | static void | |
4bc8c588 JB |
1216 | s390_store (struct prologue_value *addr, |
1217 | CORE_ADDR size, | |
1218 | struct prologue_value *value, | |
a8c99f38 | 1219 | struct s390_prologue_data *data) |
4bc8c588 JB |
1220 | { |
1221 | struct prologue_value *stack; | |
4bc8c588 | 1222 | |
a8c99f38 JB |
1223 | /* We can do it if it's definitely a reference to something on the stack. */ |
1224 | if (s390_on_stack (addr, size, data, &stack) == pv_definite_yes) | |
1225 | { | |
1226 | *stack = *value; | |
1227 | return; | |
1228 | } | |
4bc8c588 | 1229 | |
a8c99f38 JB |
1230 | /* Note: If s390_on_stack returns pv_maybe, you might think we should |
1231 | forget our cached values, as any of those might have been hit. | |
1232 | ||
1233 | However, we make the assumption that --since the fields we track | |
1234 | are save areas private to compiler, and never directly exposed to | |
1235 | the user-- every access to our data is explicit. Hence, every | |
1236 | memory access we cannot follow can't hit our data. */ | |
4bc8c588 | 1237 | } |
4bc8c588 | 1238 | |
a8c99f38 | 1239 | /* Do a SIZE-byte load from ADDR into VALUE. */ |
4bc8c588 | 1240 | static void |
a8c99f38 JB |
1241 | s390_load (struct prologue_value *addr, |
1242 | CORE_ADDR size, | |
1243 | struct prologue_value *value, | |
1244 | struct s390_prologue_data *data) | |
4bc8c588 | 1245 | { |
a8c99f38 | 1246 | struct prologue_value *stack; |
4bc8c588 | 1247 | |
a8c99f38 JB |
1248 | /* If it's a load from an in-line constant pool, then we can |
1249 | simulate that, under the assumption that the code isn't | |
1250 | going to change between the time the processor actually | |
1251 | executed it creating the current frame, and the time when | |
1252 | we're analyzing the code to unwind past that frame. */ | |
1253 | if (addr->kind == pv_constant) | |
4bc8c588 | 1254 | { |
a8c99f38 JB |
1255 | struct section_table *secp; |
1256 | secp = target_section_by_addr (¤t_target, addr->k); | |
1257 | if (secp != NULL | |
1258 | && (bfd_get_section_flags (secp->bfd, secp->the_bfd_section) | |
1259 | & SEC_READONLY)) | |
1260 | { | |
1261 | pv_set_to_constant (value, read_memory_integer (addr->k, size)); | |
1262 | return; | |
1263 | } | |
1264 | } | |
7666f43c | 1265 | |
a8c99f38 JB |
1266 | /* If it's definitely a reference to something on the stack, |
1267 | we can do that. */ | |
1268 | if (s390_on_stack (addr, size, data, &stack) == pv_definite_yes) | |
1269 | { | |
1270 | *value = *stack; | |
1271 | return; | |
5769d3cd | 1272 | } |
4bc8c588 | 1273 | |
a8c99f38 JB |
1274 | /* Otherwise, we don't know the value. */ |
1275 | pv_set_to_unknown (value); | |
1276 | } | |
1277 | ||
4bc8c588 | 1278 | |
a8c99f38 JB |
1279 | /* Analyze the prologue of the function starting at START_PC, |
1280 | continuing at most until CURRENT_PC. Initialize DATA to | |
1281 | hold all information we find out about the state of the registers | |
1282 | and stack slots. Return the address of the instruction after | |
1283 | the last one that changed the SP, FP, or back chain; or zero | |
1284 | on error. */ | |
1285 | static CORE_ADDR | |
1286 | s390_analyze_prologue (struct gdbarch *gdbarch, | |
1287 | CORE_ADDR start_pc, | |
1288 | CORE_ADDR current_pc, | |
1289 | struct s390_prologue_data *data) | |
4bc8c588 | 1290 | { |
a8c99f38 JB |
1291 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
1292 | ||
4bc8c588 | 1293 | /* Our return value: |
a8c99f38 JB |
1294 | The address of the instruction after the last one that changed |
1295 | the SP, FP, or back chain; zero if we got an error trying to | |
1296 | read memory. */ | |
1297 | CORE_ADDR result = start_pc; | |
4bc8c588 | 1298 | |
4bc8c588 JB |
1299 | /* The current PC for our abstract interpretation. */ |
1300 | CORE_ADDR pc; | |
1301 | ||
1302 | /* The address of the next instruction after that. */ | |
1303 | CORE_ADDR next_pc; | |
1304 | ||
4bc8c588 JB |
1305 | /* Set up everything's initial value. */ |
1306 | { | |
1307 | int i; | |
1308 | ||
a8c99f38 JB |
1309 | /* For the purpose of prologue tracking, we consider the GPR size to |
1310 | be equal to the ABI word size, even if it is actually larger | |
1311 | (i.e. when running a 32-bit binary under a 64-bit kernel). */ | |
1312 | data->gpr_size = word_size; | |
1313 | data->fpr_size = 8; | |
1314 | ||
4bc8c588 | 1315 | for (i = 0; i < S390_NUM_GPRS; i++) |
a8c99f38 | 1316 | pv_set_to_register (&data->gpr[i], S390_R0_REGNUM + i, 0); |
4bc8c588 JB |
1317 | |
1318 | for (i = 0; i < S390_NUM_FPRS; i++) | |
a8c99f38 | 1319 | pv_set_to_register (&data->fpr[i], S390_F0_REGNUM + i, 0); |
4bc8c588 JB |
1320 | |
1321 | for (i = 0; i < S390_NUM_SPILL_SLOTS; i++) | |
a8c99f38 | 1322 | pv_set_to_unknown (&data->spill[i]); |
4bc8c588 | 1323 | |
a8c99f38 | 1324 | pv_set_to_unknown (&data->back_chain); |
4bc8c588 JB |
1325 | } |
1326 | ||
a8c99f38 JB |
1327 | /* Start interpreting instructions, until we hit the frame's |
1328 | current PC or the first branch instruction. */ | |
1329 | for (pc = start_pc; pc > 0 && pc < current_pc; pc = next_pc) | |
5769d3cd | 1330 | { |
4bc8c588 | 1331 | bfd_byte insn[S390_MAX_INSTR_SIZE]; |
a788de9b | 1332 | int insn_len = s390_readinstruction (insn, pc); |
4bc8c588 JB |
1333 | |
1334 | /* Fields for various kinds of instructions. */ | |
a8c99f38 JB |
1335 | unsigned int b2, r1, r2, x2, r3; |
1336 | int i2, d2; | |
4bc8c588 JB |
1337 | |
1338 | /* The values of SP, FP, and back chain before this instruction, | |
1339 | for detecting instructions that change them. */ | |
1340 | struct prologue_value pre_insn_sp, pre_insn_fp, pre_insn_back_chain; | |
1341 | ||
1342 | /* If we got an error trying to read the instruction, report it. */ | |
1343 | if (insn_len < 0) | |
8ac0e65a | 1344 | { |
a8c99f38 | 1345 | result = 0; |
4bc8c588 JB |
1346 | break; |
1347 | } | |
1348 | ||
1349 | next_pc = pc + insn_len; | |
1350 | ||
a8c99f38 JB |
1351 | pre_insn_sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
1352 | pre_insn_fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; | |
1353 | pre_insn_back_chain = data->back_chain; | |
4bc8c588 | 1354 | |
a8c99f38 JB |
1355 | /* LHI r1, i2 --- load halfword immediate */ |
1356 | if (word_size == 4 | |
1357 | && is_ri (insn, op1_lhi, op2_lhi, &r1, &i2)) | |
1358 | pv_set_to_constant (&data->gpr[r1], i2); | |
4bc8c588 | 1359 | |
a8c99f38 JB |
1360 | /* LGHI r1, i2 --- load halfword immediate (64-bit version) */ |
1361 | else if (word_size == 8 | |
1362 | && is_ri (insn, op1_lghi, op2_lghi, &r1, &i2)) | |
1363 | pv_set_to_constant (&data->gpr[r1], i2); | |
4bc8c588 | 1364 | |
a8c99f38 JB |
1365 | /* LR r1, r2 --- load from register */ |
1366 | else if (word_size == 4 | |
1367 | && is_rr (insn, op_lr, &r1, &r2)) | |
1368 | data->gpr[r1] = data->gpr[r2]; | |
4bc8c588 | 1369 | |
a8c99f38 JB |
1370 | /* LGR r1, r2 --- load from register (64-bit version) */ |
1371 | else if (word_size == 8 | |
1372 | && is_rre (insn, op_lgr, &r1, &r2)) | |
1373 | data->gpr[r1] = data->gpr[r2]; | |
4bc8c588 | 1374 | |
a8c99f38 JB |
1375 | /* L r1, d2(x2, b2) --- load */ |
1376 | else if (word_size == 4 | |
1377 | && is_rx (insn, op_l, &r1, &d2, &x2, &b2)) | |
4bc8c588 | 1378 | { |
a8c99f38 | 1379 | struct prologue_value addr; |
4bc8c588 | 1380 | |
a8c99f38 JB |
1381 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1382 | s390_load (&addr, 4, &data->gpr[r1], data); | |
4bc8c588 JB |
1383 | } |
1384 | ||
a8c99f38 JB |
1385 | /* LY r1, d2(x2, b2) --- load (long-displacement version) */ |
1386 | else if (word_size == 4 | |
1387 | && is_rxy (insn, op1_ly, op2_ly, &r1, &d2, &x2, &b2)) | |
4bc8c588 JB |
1388 | { |
1389 | struct prologue_value addr; | |
4bc8c588 | 1390 | |
a8c99f38 JB |
1391 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1392 | s390_load (&addr, 4, &data->gpr[r1], data); | |
1393 | } | |
4bc8c588 | 1394 | |
a8c99f38 JB |
1395 | /* LG r1, d2(x2, b2) --- load (64-bit version) */ |
1396 | else if (word_size == 8 | |
1397 | && is_rxy (insn, op1_lg, op2_lg, &r1, &d2, &x2, &b2)) | |
1398 | { | |
1399 | struct prologue_value addr; | |
4bc8c588 | 1400 | |
a8c99f38 JB |
1401 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1402 | s390_load (&addr, 8, &data->gpr[r1], data); | |
1403 | } | |
4bc8c588 | 1404 | |
a8c99f38 JB |
1405 | /* ST r1, d2(x2, b2) --- store */ |
1406 | else if (word_size == 4 | |
1407 | && is_rx (insn, op_st, &r1, &d2, &x2, &b2)) | |
1408 | { | |
1409 | struct prologue_value addr; | |
4bc8c588 | 1410 | |
a8c99f38 JB |
1411 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1412 | s390_store (&addr, 4, &data->gpr[r1], data); | |
1413 | } | |
4bc8c588 | 1414 | |
a8c99f38 JB |
1415 | /* STY r1, d2(x2, b2) --- store (long-displacement version) */ |
1416 | else if (word_size == 4 | |
1417 | && is_rxy (insn, op1_sty, op2_sty, &r1, &d2, &x2, &b2)) | |
4bc8c588 JB |
1418 | { |
1419 | struct prologue_value addr; | |
a8c99f38 JB |
1420 | |
1421 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1422 | s390_store (&addr, 4, &data->gpr[r1], data); | |
4bc8c588 JB |
1423 | } |
1424 | ||
a8c99f38 JB |
1425 | /* STG r1, d2(x2, b2) --- store (64-bit version) */ |
1426 | else if (word_size == 8 | |
1427 | && is_rxy (insn, op1_stg, op2_stg, &r1, &d2, &x2, &b2)) | |
4bc8c588 JB |
1428 | { |
1429 | struct prologue_value addr; | |
1430 | ||
a8c99f38 JB |
1431 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1432 | s390_store (&addr, 8, &data->gpr[r1], data); | |
4bc8c588 JB |
1433 | } |
1434 | ||
1435 | /* STD r1, d2(x2,b2) --- store floating-point register */ | |
1436 | else if (is_rx (insn, op_std, &r1, &d2, &x2, &b2)) | |
1437 | { | |
1438 | struct prologue_value addr; | |
1439 | ||
a8c99f38 JB |
1440 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
1441 | s390_store (&addr, 8, &data->fpr[r1], data); | |
4bc8c588 JB |
1442 | } |
1443 | ||
a8c99f38 JB |
1444 | /* STM r1, r3, d2(b2) --- store multiple */ |
1445 | else if (word_size == 4 | |
1446 | && is_rs (insn, op_stm, &r1, &r3, &d2, &b2)) | |
4bc8c588 | 1447 | { |
a8c99f38 JB |
1448 | int regnum; |
1449 | int offset; | |
4bc8c588 JB |
1450 | struct prologue_value addr; |
1451 | ||
a8c99f38 JB |
1452 | for (regnum = r1, offset = 0; |
1453 | regnum <= r3; | |
1454 | regnum++, offset += 4) | |
1455 | { | |
1456 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); | |
1457 | s390_store (&addr, 4, &data->gpr[regnum], data); | |
1458 | } | |
4bc8c588 JB |
1459 | } |
1460 | ||
a8c99f38 JB |
1461 | /* STMY r1, r3, d2(b2) --- store multiple (long-displacement version) */ |
1462 | else if (word_size == 4 | |
1463 | && is_rsy (insn, op1_stmy, op2_stmy, &r1, &r3, &d2, &b2)) | |
4bc8c588 JB |
1464 | { |
1465 | int regnum; | |
1466 | int offset; | |
1467 | struct prologue_value addr; | |
1468 | ||
1469 | for (regnum = r1, offset = 0; | |
1470 | regnum <= r3; | |
1471 | regnum++, offset += 4) | |
1472 | { | |
a8c99f38 JB |
1473 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); |
1474 | s390_store (&addr, 4, &data->gpr[regnum], data); | |
4bc8c588 | 1475 | } |
4bc8c588 JB |
1476 | } |
1477 | ||
a8c99f38 JB |
1478 | /* STMG r1, r3, d2(b2) --- store multiple (64-bit version) */ |
1479 | else if (word_size == 8 | |
1480 | && is_rsy (insn, op1_stmg, op2_stmg, &r1, &r3, &d2, &b2)) | |
4bc8c588 JB |
1481 | { |
1482 | int regnum; | |
1483 | int offset; | |
1484 | struct prologue_value addr; | |
1485 | ||
1486 | for (regnum = r1, offset = 0; | |
1487 | regnum <= r3; | |
1488 | regnum++, offset += 8) | |
1489 | { | |
a8c99f38 JB |
1490 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); |
1491 | s390_store (&addr, 8, &data->gpr[regnum], data); | |
4bc8c588 | 1492 | } |
a8c99f38 JB |
1493 | } |
1494 | ||
1495 | /* AHI r1, i2 --- add halfword immediate */ | |
1496 | else if (word_size == 4 | |
1497 | && is_ri (insn, op1_ahi, op2_ahi, &r1, &i2)) | |
1498 | pv_add_constant (&data->gpr[r1], i2); | |
1499 | ||
1500 | /* AGHI r1, i2 --- add halfword immediate (64-bit version) */ | |
1501 | else if (word_size == 8 | |
1502 | && is_ri (insn, op1_aghi, op2_aghi, &r1, &i2)) | |
1503 | pv_add_constant (&data->gpr[r1], i2); | |
1504 | ||
1505 | /* AR r1, r2 -- add register */ | |
1506 | else if (word_size == 4 | |
1507 | && is_rr (insn, op_ar, &r1, &r2)) | |
1508 | pv_add (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1509 | ||
1510 | /* AGR r1, r2 -- add register (64-bit version) */ | |
1511 | else if (word_size == 8 | |
1512 | && is_rre (insn, op_agr, &r1, &r2)) | |
1513 | pv_add (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1514 | ||
1515 | /* A r1, d2(x2, b2) -- add */ | |
1516 | else if (word_size == 4 | |
1517 | && is_rx (insn, op_a, &r1, &d2, &x2, &b2)) | |
1518 | { | |
1519 | struct prologue_value addr; | |
1520 | struct prologue_value value; | |
1521 | ||
1522 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1523 | s390_load (&addr, 4, &value, data); | |
1524 | ||
1525 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); | |
1526 | } | |
1527 | ||
1528 | /* AY r1, d2(x2, b2) -- add (long-displacement version) */ | |
1529 | else if (word_size == 4 | |
1530 | && is_rxy (insn, op1_ay, op2_ay, &r1, &d2, &x2, &b2)) | |
1531 | { | |
1532 | struct prologue_value addr; | |
1533 | struct prologue_value value; | |
1534 | ||
1535 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1536 | s390_load (&addr, 4, &value, data); | |
1537 | ||
1538 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); | |
1539 | } | |
1540 | ||
1541 | /* AG r1, d2(x2, b2) -- add (64-bit version) */ | |
1542 | else if (word_size == 8 | |
1543 | && is_rxy (insn, op1_ag, op2_ag, &r1, &d2, &x2, &b2)) | |
1544 | { | |
1545 | struct prologue_value addr; | |
1546 | struct prologue_value value; | |
1547 | ||
1548 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1549 | s390_load (&addr, 8, &value, data); | |
1550 | ||
1551 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); | |
1552 | } | |
1553 | ||
1554 | /* SR r1, r2 -- subtract register */ | |
1555 | else if (word_size == 4 | |
1556 | && is_rr (insn, op_sr, &r1, &r2)) | |
1557 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1558 | ||
1559 | /* SGR r1, r2 -- subtract register (64-bit version) */ | |
1560 | else if (word_size == 8 | |
1561 | && is_rre (insn, op_sgr, &r1, &r2)) | |
1562 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1563 | ||
1564 | /* S r1, d2(x2, b2) -- subtract */ | |
1565 | else if (word_size == 4 | |
1566 | && is_rx (insn, op_s, &r1, &d2, &x2, &b2)) | |
1567 | { | |
1568 | struct prologue_value addr; | |
1569 | struct prologue_value value; | |
1570 | ||
1571 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1572 | s390_load (&addr, 4, &value, data); | |
1573 | ||
1574 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); | |
1575 | } | |
1576 | ||
1577 | /* SY r1, d2(x2, b2) -- subtract (long-displacement version) */ | |
1578 | else if (word_size == 4 | |
1579 | && is_rxy (insn, op1_sy, op2_sy, &r1, &d2, &x2, &b2)) | |
1580 | { | |
1581 | struct prologue_value addr; | |
1582 | struct prologue_value value; | |
1583 | ||
1584 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1585 | s390_load (&addr, 4, &value, data); | |
1586 | ||
1587 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); | |
1588 | } | |
1589 | ||
1590 | /* SG r1, d2(x2, b2) -- subtract (64-bit version) */ | |
1591 | else if (word_size == 8 | |
1592 | && is_rxy (insn, op1_sg, op2_sg, &r1, &d2, &x2, &b2)) | |
1593 | { | |
1594 | struct prologue_value addr; | |
1595 | struct prologue_value value; | |
1596 | ||
1597 | compute_x_addr (&addr, data->gpr, d2, x2, b2); | |
1598 | s390_load (&addr, 8, &value, data); | |
1599 | ||
1600 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); | |
1601 | } | |
1602 | ||
1603 | /* NR r1, r2 --- logical and */ | |
1604 | else if (word_size == 4 | |
1605 | && is_rr (insn, op_nr, &r1, &r2)) | |
1606 | pv_logical_and (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1607 | ||
1608 | /* NGR r1, r2 >--- logical and (64-bit version) */ | |
1609 | else if (word_size == 8 | |
1610 | && is_rre (insn, op_ngr, &r1, &r2)) | |
1611 | pv_logical_and (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); | |
1612 | ||
1613 | /* LA r1, d2(x2, b2) --- load address */ | |
1614 | else if (is_rx (insn, op_la, &r1, &d2, &x2, &b2)) | |
1615 | compute_x_addr (&data->gpr[r1], data->gpr, d2, x2, b2); | |
1616 | ||
1617 | /* LAY r1, d2(x2, b2) --- load address (long-displacement version) */ | |
1618 | else if (is_rxy (insn, op1_lay, op2_lay, &r1, &d2, &x2, &b2)) | |
1619 | compute_x_addr (&data->gpr[r1], data->gpr, d2, x2, b2); | |
1620 | ||
1621 | /* LARL r1, i2 --- load address relative long */ | |
1622 | else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2)) | |
1623 | pv_set_to_constant (&data->gpr[r1], pc + i2 * 2); | |
1624 | ||
1625 | /* BASR r1, 0 --- branch and save | |
1626 | Since r2 is zero, this saves the PC in r1, but doesn't branch. */ | |
1627 | else if (is_rr (insn, op_basr, &r1, &r2) | |
1628 | && r2 == 0) | |
1629 | pv_set_to_constant (&data->gpr[r1], next_pc); | |
1630 | ||
1631 | /* BRAS r1, i2 --- branch relative and save */ | |
1632 | else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2)) | |
1633 | { | |
1634 | pv_set_to_constant (&data->gpr[r1], next_pc); | |
1635 | next_pc = pc + i2 * 2; | |
4bc8c588 | 1636 | |
a8c99f38 JB |
1637 | /* We'd better not interpret any backward branches. We'll |
1638 | never terminate. */ | |
1639 | if (next_pc <= pc) | |
4bc8c588 JB |
1640 | break; |
1641 | } | |
1642 | ||
a8c99f38 JB |
1643 | /* Terminate search when hitting any other branch instruction. */ |
1644 | else if (is_rr (insn, op_basr, &r1, &r2) | |
1645 | || is_rx (insn, op_bas, &r1, &d2, &x2, &b2) | |
1646 | || is_rr (insn, op_bcr, &r1, &r2) | |
1647 | || is_rx (insn, op_bc, &r1, &d2, &x2, &b2) | |
1648 | || is_ri (insn, op1_brc, op2_brc, &r1, &i2) | |
1649 | || is_ril (insn, op1_brcl, op2_brcl, &r1, &i2) | |
1650 | || is_ril (insn, op1_brasl, op2_brasl, &r2, &i2)) | |
1651 | break; | |
1652 | ||
4bc8c588 JB |
1653 | else |
1654 | /* An instruction we don't know how to simulate. The only | |
1655 | safe thing to do would be to set every value we're tracking | |
a8c99f38 JB |
1656 | to 'unknown'. Instead, we'll be optimistic: we assume that |
1657 | we *can* interpret every instruction that the compiler uses | |
1658 | to manipulate any of the data we're interested in here -- | |
1659 | then we can just ignore anything else. */ | |
1660 | ; | |
4bc8c588 JB |
1661 | |
1662 | /* Record the address after the last instruction that changed | |
1663 | the FP, SP, or backlink. Ignore instructions that changed | |
1664 | them back to their original values --- those are probably | |
1665 | restore instructions. (The back chain is never restored, | |
1666 | just popped.) */ | |
1667 | { | |
a8c99f38 JB |
1668 | struct prologue_value *sp = &data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
1669 | struct prologue_value *fp = &data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; | |
4bc8c588 JB |
1670 | |
1671 | if ((! pv_is_identical (&pre_insn_sp, sp) | |
1672 | && ! pv_is_register (sp, S390_SP_REGNUM, 0)) | |
1673 | || (! pv_is_identical (&pre_insn_fp, fp) | |
1674 | && ! pv_is_register (fp, S390_FRAME_REGNUM, 0)) | |
a8c99f38 JB |
1675 | || ! pv_is_identical (&pre_insn_back_chain, &data->back_chain)) |
1676 | result = next_pc; | |
4bc8c588 | 1677 | } |
5769d3cd | 1678 | } |
4bc8c588 | 1679 | |
4bc8c588 | 1680 | return result; |
5769d3cd AC |
1681 | } |
1682 | ||
a8c99f38 JB |
1683 | /* Advance PC across any function entry prologue instructions to reach |
1684 | some "real" code. */ | |
1685 | static CORE_ADDR | |
1686 | s390_skip_prologue (CORE_ADDR pc) | |
1687 | { | |
1688 | struct s390_prologue_data data; | |
1689 | CORE_ADDR skip_pc; | |
1690 | skip_pc = s390_analyze_prologue (current_gdbarch, pc, (CORE_ADDR)-1, &data); | |
1691 | return skip_pc ? skip_pc : pc; | |
1692 | } | |
1693 | ||
d0f54f9d JB |
1694 | /* Return true if we are in the functin's epilogue, i.e. after the |
1695 | instruction that destroyed the function's stack frame. */ | |
1696 | static int | |
1697 | s390_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc) | |
1698 | { | |
1699 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
1700 | ||
1701 | /* In frameless functions, there's not frame to destroy and thus | |
1702 | we don't care about the epilogue. | |
1703 | ||
1704 | In functions with frame, the epilogue sequence is a pair of | |
1705 | a LM-type instruction that restores (amongst others) the | |
1706 | return register %r14 and the stack pointer %r15, followed | |
1707 | by a branch 'br %r14' --or equivalent-- that effects the | |
1708 | actual return. | |
1709 | ||
1710 | In that situation, this function needs to return 'true' in | |
1711 | exactly one case: when pc points to that branch instruction. | |
1712 | ||
1713 | Thus we try to disassemble the one instructions immediately | |
1714 | preceeding pc and check whether it is an LM-type instruction | |
1715 | modifying the stack pointer. | |
1716 | ||
1717 | Note that disassembling backwards is not reliable, so there | |
1718 | is a slight chance of false positives here ... */ | |
1719 | ||
1720 | bfd_byte insn[6]; | |
1721 | unsigned int r1, r3, b2; | |
1722 | int d2; | |
1723 | ||
1724 | if (word_size == 4 | |
1725 | && !read_memory_nobpt (pc - 4, insn, 4) | |
1726 | && is_rs (insn, op_lm, &r1, &r3, &d2, &b2) | |
1727 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) | |
1728 | return 1; | |
1729 | ||
a8c99f38 JB |
1730 | if (word_size == 4 |
1731 | && !read_memory_nobpt (pc - 6, insn, 6) | |
1732 | && is_rsy (insn, op1_lmy, op2_lmy, &r1, &r3, &d2, &b2) | |
1733 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) | |
1734 | return 1; | |
1735 | ||
d0f54f9d JB |
1736 | if (word_size == 8 |
1737 | && !read_memory_nobpt (pc - 6, insn, 6) | |
a8c99f38 | 1738 | && is_rsy (insn, op1_lmg, op2_lmg, &r1, &r3, &d2, &b2) |
d0f54f9d JB |
1739 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) |
1740 | return 1; | |
1741 | ||
1742 | return 0; | |
1743 | } | |
5769d3cd | 1744 | |
a8c99f38 JB |
1745 | |
1746 | /* Normal stack frames. */ | |
1747 | ||
1748 | struct s390_unwind_cache { | |
1749 | ||
1750 | CORE_ADDR func; | |
1751 | CORE_ADDR frame_base; | |
1752 | CORE_ADDR local_base; | |
1753 | ||
1754 | struct trad_frame_saved_reg *saved_regs; | |
1755 | }; | |
1756 | ||
a78f21af | 1757 | static int |
a8c99f38 JB |
1758 | s390_prologue_frame_unwind_cache (struct frame_info *next_frame, |
1759 | struct s390_unwind_cache *info) | |
5769d3cd | 1760 | { |
a8c99f38 JB |
1761 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
1762 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
1763 | struct s390_prologue_data data; | |
1764 | struct prologue_value *fp = &data.gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; | |
1765 | struct prologue_value *sp = &data.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; | |
1766 | int slot_num; | |
1767 | CORE_ADDR slot_addr; | |
1768 | CORE_ADDR func; | |
1769 | CORE_ADDR result; | |
1770 | ULONGEST reg; | |
1771 | CORE_ADDR prev_sp; | |
1772 | int frame_pointer; | |
1773 | int size; | |
1774 | ||
1775 | /* Try to find the function start address. If we can't find it, we don't | |
1776 | bother searching for it -- with modern compilers this would be mostly | |
1777 | pointless anyway. Trust that we'll either have valid DWARF-2 CFI data | |
1778 | or else a valid backchain ... */ | |
1779 | func = frame_func_unwind (next_frame); | |
1780 | if (!func) | |
1781 | return 0; | |
5769d3cd | 1782 | |
a8c99f38 JB |
1783 | /* Try to analyze the prologue. */ |
1784 | result = s390_analyze_prologue (gdbarch, func, | |
1785 | frame_pc_unwind (next_frame), &data); | |
1786 | if (!result) | |
5769d3cd | 1787 | return 0; |
5769d3cd | 1788 | |
a8c99f38 JB |
1789 | /* If this was successful, we should have found the instruction that |
1790 | sets the stack pointer register to the previous value of the stack | |
1791 | pointer minus the frame size. */ | |
1792 | if (sp->kind != pv_register || sp->reg != S390_SP_REGNUM) | |
5769d3cd | 1793 | return 0; |
a8c99f38 JB |
1794 | |
1795 | /* A frame size of zero at this point can mean either a real | |
1796 | frameless function, or else a failure to find the prologue. | |
1797 | Perform some sanity checks to verify we really have a | |
1798 | frameless function. */ | |
1799 | if (sp->k == 0) | |
5769d3cd | 1800 | { |
a8c99f38 JB |
1801 | /* If the next frame is a NORMAL_FRAME, this frame *cannot* have frame |
1802 | size zero. This is only possible if the next frame is a sentinel | |
1803 | frame, a dummy frame, or a signal trampoline frame. */ | |
1804 | if (get_frame_type (next_frame) == NORMAL_FRAME | |
1805 | /* For some reason, sentinel frames are NORMAL_FRAMEs | |
1806 | -- but they have negative frame level. */ | |
1807 | && frame_relative_level (next_frame) >= 0) | |
5769d3cd | 1808 | return 0; |
5769d3cd | 1809 | |
a8c99f38 JB |
1810 | /* If we really have a frameless function, %r14 must be valid |
1811 | -- in particular, it must point to a different function. */ | |
1812 | reg = frame_unwind_register_unsigned (next_frame, S390_RETADDR_REGNUM); | |
1813 | reg = gdbarch_addr_bits_remove (gdbarch, reg) - 1; | |
1814 | if (get_pc_function_start (reg) == func) | |
5769d3cd | 1815 | { |
a8c99f38 JB |
1816 | /* However, there is one case where it *is* valid for %r14 |
1817 | to point to the same function -- if this is a recursive | |
1818 | call, and we have stopped in the prologue *before* the | |
1819 | stack frame was allocated. | |
1820 | ||
1821 | Recognize this case by looking ahead a bit ... */ | |
5769d3cd | 1822 | |
a8c99f38 JB |
1823 | struct s390_prologue_data data2; |
1824 | struct prologue_value *sp = &data2.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; | |
1825 | ||
1826 | if (!(s390_analyze_prologue (gdbarch, func, (CORE_ADDR)-1, &data2) | |
1827 | && sp->kind == pv_register | |
1828 | && sp->reg == S390_SP_REGNUM | |
1829 | && sp->k != 0)) | |
1830 | return 0; | |
5769d3cd | 1831 | } |
5769d3cd | 1832 | } |
5769d3cd AC |
1833 | |
1834 | ||
a8c99f38 JB |
1835 | /* OK, we've found valid prologue data. */ |
1836 | size = -sp->k; | |
5769d3cd | 1837 | |
a8c99f38 JB |
1838 | /* If the frame pointer originally also holds the same value |
1839 | as the stack pointer, we're probably using it. If it holds | |
1840 | some other value -- even a constant offset -- it is most | |
1841 | likely used as temp register. */ | |
1842 | if (pv_is_identical (sp, fp)) | |
1843 | frame_pointer = S390_FRAME_REGNUM; | |
1844 | else | |
1845 | frame_pointer = S390_SP_REGNUM; | |
1846 | ||
1847 | /* If we've detected a function with stack frame, we'll still have to | |
1848 | treat it as frameless if we're currently within the function epilog | |
1849 | code at a point where the frame pointer has already been restored. | |
1850 | This can only happen in an innermost frame. */ | |
1851 | if (size > 0 | |
1852 | && (get_frame_type (next_frame) != NORMAL_FRAME | |
1853 | || frame_relative_level (next_frame) < 0)) | |
5769d3cd | 1854 | { |
a8c99f38 JB |
1855 | /* See the comment in s390_in_function_epilogue_p on why this is |
1856 | not completely reliable ... */ | |
1857 | if (s390_in_function_epilogue_p (gdbarch, frame_pc_unwind (next_frame))) | |
5769d3cd | 1858 | { |
a8c99f38 JB |
1859 | memset (&data, 0, sizeof (data)); |
1860 | size = 0; | |
1861 | frame_pointer = S390_SP_REGNUM; | |
5769d3cd | 1862 | } |
5769d3cd | 1863 | } |
5769d3cd | 1864 | |
a8c99f38 JB |
1865 | /* Once we know the frame register and the frame size, we can unwind |
1866 | the current value of the frame register from the next frame, and | |
1867 | add back the frame size to arrive that the previous frame's | |
1868 | stack pointer value. */ | |
1869 | prev_sp = frame_unwind_register_unsigned (next_frame, frame_pointer) + size; | |
5769d3cd | 1870 | |
a8c99f38 JB |
1871 | /* Scan the spill array; if a spill slot says it holds the |
1872 | original value of some register, then record that slot's | |
1873 | address as the place that register was saved. */ | |
5769d3cd | 1874 | |
a8c99f38 JB |
1875 | /* Slots for %r2 .. %r15. */ |
1876 | for (slot_num = 0, slot_addr = prev_sp + 2 * data.gpr_size; | |
1877 | slot_num < 14; | |
1878 | slot_num++, slot_addr += data.gpr_size) | |
5769d3cd | 1879 | { |
a8c99f38 JB |
1880 | struct prologue_value *slot = &data.spill[slot_num]; |
1881 | ||
1882 | if (slot->kind == pv_register | |
1883 | && slot->k == 0) | |
1884 | info->saved_regs[slot->reg].addr = slot_addr; | |
5769d3cd | 1885 | } |
5769d3cd | 1886 | |
a8c99f38 JB |
1887 | /* Slots for %f0 .. %f6. */ |
1888 | for (slot_num = 14, slot_addr = prev_sp + 16 * data.gpr_size; | |
1889 | slot_num < S390_NUM_SPILL_SLOTS; | |
1890 | slot_num++, slot_addr += data.fpr_size) | |
5769d3cd | 1891 | { |
a8c99f38 JB |
1892 | struct prologue_value *slot = &data.spill[slot_num]; |
1893 | ||
1894 | if (slot->kind == pv_register | |
1895 | && slot->k == 0) | |
1896 | info->saved_regs[slot->reg].addr = slot_addr; | |
1897 | } | |
1898 | ||
1899 | /* Function return will set PC to %r14. */ | |
1900 | info->saved_regs[S390_PC_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM]; | |
1901 | ||
1902 | /* In frameless functions, we unwind simply by moving the return | |
1903 | address to the PC. However, if we actually stored to the | |
1904 | save area, use that -- we might only think the function frameless | |
1905 | because we're in the middle of the prologue ... */ | |
1906 | if (size == 0 | |
1907 | && !trad_frame_addr_p (info->saved_regs, S390_PC_REGNUM)) | |
1908 | { | |
1909 | info->saved_regs[S390_PC_REGNUM].realreg = S390_RETADDR_REGNUM; | |
5769d3cd | 1910 | } |
a8c99f38 JB |
1911 | |
1912 | /* Another sanity check: unless this is a frameless function, | |
1913 | we should have found spill slots for SP and PC. | |
1914 | If not, we cannot unwind further -- this happens e.g. in | |
1915 | libc's thread_start routine. */ | |
1916 | if (size > 0) | |
5769d3cd | 1917 | { |
a8c99f38 JB |
1918 | if (!trad_frame_addr_p (info->saved_regs, S390_SP_REGNUM) |
1919 | || !trad_frame_addr_p (info->saved_regs, S390_PC_REGNUM)) | |
1920 | prev_sp = -1; | |
5769d3cd | 1921 | } |
a8c99f38 JB |
1922 | |
1923 | /* We use the current value of the frame register as local_base, | |
1924 | and the top of the register save area as frame_base. */ | |
1925 | if (prev_sp != -1) | |
1926 | { | |
1927 | info->frame_base = prev_sp + 16*word_size + 32; | |
1928 | info->local_base = prev_sp - size; | |
1929 | } | |
1930 | ||
1931 | info->func = func; | |
1932 | return 1; | |
5769d3cd AC |
1933 | } |
1934 | ||
a78f21af | 1935 | static void |
a8c99f38 JB |
1936 | s390_backchain_frame_unwind_cache (struct frame_info *next_frame, |
1937 | struct s390_unwind_cache *info) | |
5769d3cd | 1938 | { |
a8c99f38 JB |
1939 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
1940 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
1941 | CORE_ADDR backchain; | |
1942 | ULONGEST reg; | |
1943 | LONGEST sp; | |
1944 | ||
1945 | /* Get the backchain. */ | |
1946 | reg = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); | |
1947 | backchain = read_memory_unsigned_integer (reg, word_size); | |
1948 | ||
1949 | /* A zero backchain terminates the frame chain. As additional | |
1950 | sanity check, let's verify that the spill slot for SP in the | |
1951 | save area pointed to by the backchain in fact links back to | |
1952 | the save area. */ | |
1953 | if (backchain != 0 | |
1954 | && safe_read_memory_integer (backchain + 15*word_size, word_size, &sp) | |
1955 | && (CORE_ADDR)sp == backchain) | |
1956 | { | |
1957 | /* We don't know which registers were saved, but it will have | |
1958 | to be at least %r14 and %r15. This will allow us to continue | |
1959 | unwinding, but other prev-frame registers may be incorrect ... */ | |
1960 | info->saved_regs[S390_SP_REGNUM].addr = backchain + 15*word_size; | |
1961 | info->saved_regs[S390_RETADDR_REGNUM].addr = backchain + 14*word_size; | |
1962 | ||
1963 | /* Function return will set PC to %r14. */ | |
1964 | info->saved_regs[S390_PC_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM]; | |
1965 | ||
1966 | /* We use the current value of the frame register as local_base, | |
1967 | and the top of the register save area as frame_base. */ | |
1968 | info->frame_base = backchain + 16*word_size + 32; | |
1969 | info->local_base = reg; | |
1970 | } | |
1971 | ||
1972 | info->func = frame_pc_unwind (next_frame); | |
5769d3cd AC |
1973 | } |
1974 | ||
a8c99f38 JB |
1975 | static struct s390_unwind_cache * |
1976 | s390_frame_unwind_cache (struct frame_info *next_frame, | |
1977 | void **this_prologue_cache) | |
1978 | { | |
1979 | struct s390_unwind_cache *info; | |
1980 | if (*this_prologue_cache) | |
1981 | return *this_prologue_cache; | |
1982 | ||
1983 | info = FRAME_OBSTACK_ZALLOC (struct s390_unwind_cache); | |
1984 | *this_prologue_cache = info; | |
1985 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); | |
1986 | info->func = -1; | |
1987 | info->frame_base = -1; | |
1988 | info->local_base = -1; | |
1989 | ||
1990 | /* Try to use prologue analysis to fill the unwind cache. | |
1991 | If this fails, fall back to reading the stack backchain. */ | |
1992 | if (!s390_prologue_frame_unwind_cache (next_frame, info)) | |
1993 | s390_backchain_frame_unwind_cache (next_frame, info); | |
1994 | ||
1995 | return info; | |
1996 | } | |
5769d3cd | 1997 | |
a78f21af | 1998 | static void |
a8c99f38 JB |
1999 | s390_frame_this_id (struct frame_info *next_frame, |
2000 | void **this_prologue_cache, | |
2001 | struct frame_id *this_id) | |
5769d3cd | 2002 | { |
a8c99f38 JB |
2003 | struct s390_unwind_cache *info |
2004 | = s390_frame_unwind_cache (next_frame, this_prologue_cache); | |
5769d3cd | 2005 | |
a8c99f38 JB |
2006 | if (info->frame_base == -1) |
2007 | return; | |
5769d3cd | 2008 | |
a8c99f38 | 2009 | *this_id = frame_id_build (info->frame_base, info->func); |
5769d3cd AC |
2010 | } |
2011 | ||
a8c99f38 JB |
2012 | static void |
2013 | s390_frame_prev_register (struct frame_info *next_frame, | |
2014 | void **this_prologue_cache, | |
2015 | int regnum, int *optimizedp, | |
2016 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
2017 | int *realnump, void *bufferp) | |
2018 | { | |
2019 | struct s390_unwind_cache *info | |
2020 | = s390_frame_unwind_cache (next_frame, this_prologue_cache); | |
2021 | trad_frame_prev_register (next_frame, info->saved_regs, regnum, | |
2022 | optimizedp, lvalp, addrp, realnump, bufferp); | |
2023 | } | |
2024 | ||
2025 | static const struct frame_unwind s390_frame_unwind = { | |
2026 | NORMAL_FRAME, | |
2027 | s390_frame_this_id, | |
2028 | s390_frame_prev_register | |
2029 | }; | |
2030 | ||
2031 | static const struct frame_unwind * | |
2032 | s390_frame_sniffer (struct frame_info *next_frame) | |
2033 | { | |
2034 | return &s390_frame_unwind; | |
2035 | } | |
5769d3cd AC |
2036 | |
2037 | ||
a8c99f38 JB |
2038 | /* PLT stub stack frames. */ |
2039 | ||
2040 | struct s390_pltstub_unwind_cache { | |
2041 | ||
2042 | CORE_ADDR frame_base; | |
2043 | struct trad_frame_saved_reg *saved_regs; | |
2044 | }; | |
2045 | ||
2046 | static struct s390_pltstub_unwind_cache * | |
2047 | s390_pltstub_frame_unwind_cache (struct frame_info *next_frame, | |
2048 | void **this_prologue_cache) | |
5769d3cd | 2049 | { |
a8c99f38 JB |
2050 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
2051 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
2052 | struct s390_pltstub_unwind_cache *info; | |
2053 | ULONGEST reg; | |
5c3cf190 | 2054 | |
a8c99f38 JB |
2055 | if (*this_prologue_cache) |
2056 | return *this_prologue_cache; | |
5c3cf190 | 2057 | |
a8c99f38 JB |
2058 | info = FRAME_OBSTACK_ZALLOC (struct s390_pltstub_unwind_cache); |
2059 | *this_prologue_cache = info; | |
2060 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); | |
2061 | ||
2062 | /* The return address is in register %r14. */ | |
2063 | info->saved_regs[S390_PC_REGNUM].realreg = S390_RETADDR_REGNUM; | |
2064 | ||
2065 | /* Retrieve stack pointer and determine our frame base. */ | |
2066 | reg = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); | |
2067 | info->frame_base = reg + 16*word_size + 32; | |
2068 | ||
2069 | return info; | |
5769d3cd AC |
2070 | } |
2071 | ||
a8c99f38 JB |
2072 | static void |
2073 | s390_pltstub_frame_this_id (struct frame_info *next_frame, | |
2074 | void **this_prologue_cache, | |
2075 | struct frame_id *this_id) | |
5769d3cd | 2076 | { |
a8c99f38 JB |
2077 | struct s390_pltstub_unwind_cache *info |
2078 | = s390_pltstub_frame_unwind_cache (next_frame, this_prologue_cache); | |
2079 | *this_id = frame_id_build (info->frame_base, frame_pc_unwind (next_frame)); | |
2080 | } | |
5769d3cd | 2081 | |
a8c99f38 JB |
2082 | static void |
2083 | s390_pltstub_frame_prev_register (struct frame_info *next_frame, | |
2084 | void **this_prologue_cache, | |
2085 | int regnum, int *optimizedp, | |
2086 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
2087 | int *realnump, void *bufferp) | |
2088 | { | |
2089 | struct s390_pltstub_unwind_cache *info | |
2090 | = s390_pltstub_frame_unwind_cache (next_frame, this_prologue_cache); | |
2091 | trad_frame_prev_register (next_frame, info->saved_regs, regnum, | |
2092 | optimizedp, lvalp, addrp, realnump, bufferp); | |
2093 | } | |
2094 | ||
2095 | static const struct frame_unwind s390_pltstub_frame_unwind = { | |
2096 | NORMAL_FRAME, | |
2097 | s390_pltstub_frame_this_id, | |
2098 | s390_pltstub_frame_prev_register | |
2099 | }; | |
5769d3cd | 2100 | |
a8c99f38 JB |
2101 | static const struct frame_unwind * |
2102 | s390_pltstub_frame_sniffer (struct frame_info *next_frame) | |
2103 | { | |
2104 | if (!in_plt_section (frame_pc_unwind (next_frame), NULL)) | |
2105 | return NULL; | |
5769d3cd | 2106 | |
a8c99f38 JB |
2107 | return &s390_pltstub_frame_unwind; |
2108 | } | |
5769d3cd AC |
2109 | |
2110 | ||
a8c99f38 | 2111 | /* Signal trampoline stack frames. */ |
5769d3cd | 2112 | |
a8c99f38 JB |
2113 | struct s390_sigtramp_unwind_cache { |
2114 | CORE_ADDR frame_base; | |
2115 | struct trad_frame_saved_reg *saved_regs; | |
2116 | }; | |
5769d3cd | 2117 | |
a8c99f38 JB |
2118 | static struct s390_sigtramp_unwind_cache * |
2119 | s390_sigtramp_frame_unwind_cache (struct frame_info *next_frame, | |
2120 | void **this_prologue_cache) | |
5769d3cd | 2121 | { |
a8c99f38 JB |
2122 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
2123 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
2124 | struct s390_sigtramp_unwind_cache *info; | |
2125 | ULONGEST this_sp, prev_sp; | |
2126 | CORE_ADDR next_ra, next_cfa, sigreg_ptr; | |
2127 | int i; | |
2128 | ||
2129 | if (*this_prologue_cache) | |
2130 | return *this_prologue_cache; | |
5769d3cd | 2131 | |
a8c99f38 JB |
2132 | info = FRAME_OBSTACK_ZALLOC (struct s390_sigtramp_unwind_cache); |
2133 | *this_prologue_cache = info; | |
2134 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); | |
2135 | ||
2136 | this_sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); | |
2137 | next_ra = frame_pc_unwind (next_frame); | |
2138 | next_cfa = this_sp + 16*word_size + 32; | |
2139 | ||
2140 | /* New-style RT frame: | |
2141 | retcode + alignment (8 bytes) | |
2142 | siginfo (128 bytes) | |
2143 | ucontext (contains sigregs at offset 5 words) */ | |
2144 | if (next_ra == next_cfa) | |
2145 | { | |
2146 | sigreg_ptr = next_cfa + 8 + 128 + 5*word_size; | |
2147 | } | |
2148 | ||
2149 | /* Old-style RT frame and all non-RT frames: | |
2150 | old signal mask (8 bytes) | |
2151 | pointer to sigregs */ | |
5769d3cd AC |
2152 | else |
2153 | { | |
a8c99f38 JB |
2154 | sigreg_ptr = read_memory_unsigned_integer (next_cfa + 8, word_size); |
2155 | } | |
5769d3cd | 2156 | |
a8c99f38 JB |
2157 | /* The sigregs structure looks like this: |
2158 | long psw_mask; | |
2159 | long psw_addr; | |
2160 | long gprs[16]; | |
2161 | int acrs[16]; | |
2162 | int fpc; | |
2163 | int __pad; | |
2164 | double fprs[16]; */ | |
5769d3cd | 2165 | |
a8c99f38 JB |
2166 | /* Let's ignore the PSW mask, it will not be restored anyway. */ |
2167 | sigreg_ptr += word_size; | |
2168 | ||
2169 | /* Next comes the PSW address. */ | |
2170 | info->saved_regs[S390_PC_REGNUM].addr = sigreg_ptr; | |
2171 | sigreg_ptr += word_size; | |
2172 | ||
2173 | /* Then the GPRs. */ | |
2174 | for (i = 0; i < 16; i++) | |
2175 | { | |
2176 | info->saved_regs[S390_R0_REGNUM + i].addr = sigreg_ptr; | |
2177 | sigreg_ptr += word_size; | |
2178 | } | |
2179 | ||
2180 | /* Then the ACRs. */ | |
2181 | for (i = 0; i < 16; i++) | |
2182 | { | |
2183 | info->saved_regs[S390_A0_REGNUM + i].addr = sigreg_ptr; | |
2184 | sigreg_ptr += 4; | |
5769d3cd | 2185 | } |
5769d3cd | 2186 | |
a8c99f38 JB |
2187 | /* The floating-point control word. */ |
2188 | info->saved_regs[S390_FPC_REGNUM].addr = sigreg_ptr; | |
2189 | sigreg_ptr += 8; | |
5769d3cd | 2190 | |
a8c99f38 JB |
2191 | /* And finally the FPRs. */ |
2192 | for (i = 0; i < 16; i++) | |
2193 | { | |
2194 | info->saved_regs[S390_F0_REGNUM + i].addr = sigreg_ptr; | |
2195 | sigreg_ptr += 8; | |
2196 | } | |
2197 | ||
2198 | /* Restore the previous frame's SP. */ | |
2199 | prev_sp = read_memory_unsigned_integer ( | |
2200 | info->saved_regs[S390_SP_REGNUM].addr, | |
2201 | word_size); | |
5769d3cd | 2202 | |
a8c99f38 JB |
2203 | /* Determine our frame base. */ |
2204 | info->frame_base = prev_sp + 16*word_size + 32; | |
5769d3cd | 2205 | |
a8c99f38 | 2206 | return info; |
5769d3cd AC |
2207 | } |
2208 | ||
a8c99f38 JB |
2209 | static void |
2210 | s390_sigtramp_frame_this_id (struct frame_info *next_frame, | |
2211 | void **this_prologue_cache, | |
2212 | struct frame_id *this_id) | |
5769d3cd | 2213 | { |
a8c99f38 JB |
2214 | struct s390_sigtramp_unwind_cache *info |
2215 | = s390_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); | |
2216 | *this_id = frame_id_build (info->frame_base, frame_pc_unwind (next_frame)); | |
5769d3cd AC |
2217 | } |
2218 | ||
4c8287ac | 2219 | static void |
a8c99f38 JB |
2220 | s390_sigtramp_frame_prev_register (struct frame_info *next_frame, |
2221 | void **this_prologue_cache, | |
2222 | int regnum, int *optimizedp, | |
2223 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
2224 | int *realnump, void *bufferp) | |
2225 | { | |
2226 | struct s390_sigtramp_unwind_cache *info | |
2227 | = s390_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); | |
2228 | trad_frame_prev_register (next_frame, info->saved_regs, regnum, | |
2229 | optimizedp, lvalp, addrp, realnump, bufferp); | |
2230 | } | |
2231 | ||
2232 | static const struct frame_unwind s390_sigtramp_frame_unwind = { | |
2233 | SIGTRAMP_FRAME, | |
2234 | s390_sigtramp_frame_this_id, | |
2235 | s390_sigtramp_frame_prev_register | |
2236 | }; | |
2237 | ||
2238 | static const struct frame_unwind * | |
2239 | s390_sigtramp_frame_sniffer (struct frame_info *next_frame) | |
5769d3cd | 2240 | { |
a8c99f38 JB |
2241 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
2242 | bfd_byte sigreturn[2]; | |
4c8287ac | 2243 | |
a8c99f38 JB |
2244 | if (read_memory_nobpt (pc, sigreturn, 2)) |
2245 | return NULL; | |
4c8287ac | 2246 | |
a8c99f38 JB |
2247 | if (sigreturn[0] != 0x0a /* svc */) |
2248 | return NULL; | |
5769d3cd | 2249 | |
a8c99f38 JB |
2250 | if (sigreturn[1] != 119 /* sigreturn */ |
2251 | && sigreturn[1] != 173 /* rt_sigreturn */) | |
2252 | return NULL; | |
2253 | ||
2254 | return &s390_sigtramp_frame_unwind; | |
5769d3cd AC |
2255 | } |
2256 | ||
4c8287ac | 2257 | |
a8c99f38 JB |
2258 | /* Frame base handling. */ |
2259 | ||
2260 | static CORE_ADDR | |
2261 | s390_frame_base_address (struct frame_info *next_frame, void **this_cache) | |
4c8287ac | 2262 | { |
a8c99f38 JB |
2263 | struct s390_unwind_cache *info |
2264 | = s390_frame_unwind_cache (next_frame, this_cache); | |
2265 | return info->frame_base; | |
2266 | } | |
2267 | ||
2268 | static CORE_ADDR | |
2269 | s390_local_base_address (struct frame_info *next_frame, void **this_cache) | |
2270 | { | |
2271 | struct s390_unwind_cache *info | |
2272 | = s390_frame_unwind_cache (next_frame, this_cache); | |
2273 | return info->local_base; | |
2274 | } | |
2275 | ||
2276 | static const struct frame_base s390_frame_base = { | |
2277 | &s390_frame_unwind, | |
2278 | s390_frame_base_address, | |
2279 | s390_local_base_address, | |
2280 | s390_local_base_address | |
2281 | }; | |
2282 | ||
2283 | static CORE_ADDR | |
2284 | s390_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
2285 | { | |
2286 | ULONGEST pc; | |
2287 | pc = frame_unwind_register_unsigned (next_frame, S390_PC_REGNUM); | |
2288 | return gdbarch_addr_bits_remove (gdbarch, pc); | |
2289 | } | |
2290 | ||
2291 | static CORE_ADDR | |
2292 | s390_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
2293 | { | |
2294 | ULONGEST sp; | |
2295 | sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); | |
2296 | return gdbarch_addr_bits_remove (gdbarch, sp); | |
4c8287ac JB |
2297 | } |
2298 | ||
2299 | ||
b0cf273e JB |
2300 | /* Dummy function calls. */ |
2301 | ||
78f8b424 JB |
2302 | /* Return non-zero if TYPE is an integer-like type, zero otherwise. |
2303 | "Integer-like" types are those that should be passed the way | |
2304 | integers are: integers, enums, ranges, characters, and booleans. */ | |
2305 | static int | |
2306 | is_integer_like (struct type *type) | |
2307 | { | |
2308 | enum type_code code = TYPE_CODE (type); | |
2309 | ||
2310 | return (code == TYPE_CODE_INT | |
2311 | || code == TYPE_CODE_ENUM | |
2312 | || code == TYPE_CODE_RANGE | |
2313 | || code == TYPE_CODE_CHAR | |
2314 | || code == TYPE_CODE_BOOL); | |
2315 | } | |
2316 | ||
78f8b424 JB |
2317 | /* Return non-zero if TYPE is a pointer-like type, zero otherwise. |
2318 | "Pointer-like" types are those that should be passed the way | |
2319 | pointers are: pointers and references. */ | |
2320 | static int | |
2321 | is_pointer_like (struct type *type) | |
2322 | { | |
2323 | enum type_code code = TYPE_CODE (type); | |
2324 | ||
2325 | return (code == TYPE_CODE_PTR | |
2326 | || code == TYPE_CODE_REF); | |
2327 | } | |
2328 | ||
2329 | ||
20a940cc JB |
2330 | /* Return non-zero if TYPE is a `float singleton' or `double |
2331 | singleton', zero otherwise. | |
2332 | ||
2333 | A `T singleton' is a struct type with one member, whose type is | |
2334 | either T or a `T singleton'. So, the following are all float | |
2335 | singletons: | |
2336 | ||
2337 | struct { float x }; | |
2338 | struct { struct { float x; } x; }; | |
2339 | struct { struct { struct { float x; } x; } x; }; | |
2340 | ||
2341 | ... and so on. | |
2342 | ||
b0cf273e JB |
2343 | All such structures are passed as if they were floats or doubles, |
2344 | as the (revised) ABI says. */ | |
20a940cc JB |
2345 | static int |
2346 | is_float_singleton (struct type *type) | |
2347 | { | |
b0cf273e JB |
2348 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
2349 | { | |
2350 | struct type *singleton_type = TYPE_FIELD_TYPE (type, 0); | |
2351 | CHECK_TYPEDEF (singleton_type); | |
2352 | ||
2353 | return (TYPE_CODE (singleton_type) == TYPE_CODE_FLT | |
2354 | || is_float_singleton (singleton_type)); | |
2355 | } | |
2356 | ||
2357 | return 0; | |
20a940cc JB |
2358 | } |
2359 | ||
2360 | ||
2361 | /* Return non-zero if TYPE is a struct-like type, zero otherwise. | |
2362 | "Struct-like" types are those that should be passed as structs are: | |
2363 | structs and unions. | |
2364 | ||
2365 | As an odd quirk, not mentioned in the ABI, GCC passes float and | |
2366 | double singletons as if they were a plain float, double, etc. (The | |
2367 | corresponding union types are handled normally.) So we exclude | |
2368 | those types here. *shrug* */ | |
2369 | static int | |
2370 | is_struct_like (struct type *type) | |
2371 | { | |
2372 | enum type_code code = TYPE_CODE (type); | |
2373 | ||
2374 | return (code == TYPE_CODE_UNION | |
2375 | || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type))); | |
2376 | } | |
2377 | ||
2378 | ||
2379 | /* Return non-zero if TYPE is a float-like type, zero otherwise. | |
2380 | "Float-like" types are those that should be passed as | |
2381 | floating-point values are. | |
2382 | ||
2383 | You'd think this would just be floats, doubles, long doubles, etc. | |
2384 | But as an odd quirk, not mentioned in the ABI, GCC passes float and | |
2385 | double singletons as if they were a plain float, double, etc. (The | |
4d819d0e | 2386 | corresponding union types are handled normally.) So we include |
20a940cc JB |
2387 | those types here. *shrug* */ |
2388 | static int | |
2389 | is_float_like (struct type *type) | |
2390 | { | |
2391 | return (TYPE_CODE (type) == TYPE_CODE_FLT | |
2392 | || is_float_singleton (type)); | |
2393 | } | |
2394 | ||
2395 | ||
78f8b424 | 2396 | static int |
b0cf273e | 2397 | is_power_of_two (unsigned int n) |
78f8b424 | 2398 | { |
b0cf273e | 2399 | return ((n & (n - 1)) == 0); |
78f8b424 JB |
2400 | } |
2401 | ||
b0cf273e JB |
2402 | /* Return non-zero if TYPE should be passed as a pointer to a copy, |
2403 | zero otherwise. */ | |
4d819d0e | 2404 | static int |
b0cf273e | 2405 | s390_function_arg_pass_by_reference (struct type *type) |
4d819d0e JB |
2406 | { |
2407 | unsigned length = TYPE_LENGTH (type); | |
b0cf273e JB |
2408 | if (length > 8) |
2409 | return 1; | |
4d819d0e | 2410 | |
b0cf273e JB |
2411 | /* FIXME: All complex and vector types are also returned by reference. */ |
2412 | return is_struct_like (type) && !is_power_of_two (length); | |
4d819d0e JB |
2413 | } |
2414 | ||
b0cf273e JB |
2415 | /* Return non-zero if TYPE should be passed in a float register |
2416 | if possible. */ | |
78f8b424 | 2417 | static int |
b0cf273e | 2418 | s390_function_arg_float (struct type *type) |
78f8b424 | 2419 | { |
78f8b424 | 2420 | unsigned length = TYPE_LENGTH (type); |
b0cf273e JB |
2421 | if (length > 8) |
2422 | return 0; | |
78f8b424 | 2423 | |
b0cf273e | 2424 | return is_float_like (type); |
4d819d0e JB |
2425 | } |
2426 | ||
b0cf273e JB |
2427 | /* Return non-zero if TYPE should be passed in an integer register |
2428 | (or a pair of integer registers) if possible. */ | |
78f8b424 | 2429 | static int |
b0cf273e | 2430 | s390_function_arg_integer (struct type *type) |
78f8b424 | 2431 | { |
78f8b424 | 2432 | unsigned length = TYPE_LENGTH (type); |
b0cf273e JB |
2433 | if (length > 8) |
2434 | return 0; | |
78f8b424 | 2435 | |
b0cf273e JB |
2436 | return is_integer_like (type) |
2437 | || is_pointer_like (type) | |
2438 | || (is_struct_like (type) && is_power_of_two (length)); | |
78f8b424 JB |
2439 | } |
2440 | ||
78f8b424 JB |
2441 | /* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full |
2442 | word as required for the ABI. */ | |
2443 | static LONGEST | |
2444 | extend_simple_arg (struct value *arg) | |
2445 | { | |
2446 | struct type *type = VALUE_TYPE (arg); | |
2447 | ||
2448 | /* Even structs get passed in the least significant bits of the | |
2449 | register / memory word. It's not really right to extract them as | |
2450 | an integer, but it does take care of the extension. */ | |
2451 | if (TYPE_UNSIGNED (type)) | |
2452 | return extract_unsigned_integer (VALUE_CONTENTS (arg), | |
2453 | TYPE_LENGTH (type)); | |
2454 | else | |
2455 | return extract_signed_integer (VALUE_CONTENTS (arg), | |
2456 | TYPE_LENGTH (type)); | |
2457 | } | |
2458 | ||
2459 | ||
78f8b424 JB |
2460 | /* Return the alignment required by TYPE. */ |
2461 | static int | |
2462 | alignment_of (struct type *type) | |
2463 | { | |
2464 | int alignment; | |
2465 | ||
2466 | if (is_integer_like (type) | |
2467 | || is_pointer_like (type) | |
2468 | || TYPE_CODE (type) == TYPE_CODE_FLT) | |
2469 | alignment = TYPE_LENGTH (type); | |
2470 | else if (TYPE_CODE (type) == TYPE_CODE_STRUCT | |
2471 | || TYPE_CODE (type) == TYPE_CODE_UNION) | |
2472 | { | |
2473 | int i; | |
2474 | ||
2475 | alignment = 1; | |
2476 | for (i = 0; i < TYPE_NFIELDS (type); i++) | |
2477 | { | |
2478 | int field_alignment = alignment_of (TYPE_FIELD_TYPE (type, i)); | |
2479 | ||
2480 | if (field_alignment > alignment) | |
2481 | alignment = field_alignment; | |
2482 | } | |
2483 | } | |
2484 | else | |
2485 | alignment = 1; | |
2486 | ||
2487 | /* Check that everything we ever return is a power of two. Lots of | |
2488 | code doesn't want to deal with aligning things to arbitrary | |
2489 | boundaries. */ | |
2490 | gdb_assert ((alignment & (alignment - 1)) == 0); | |
2491 | ||
2492 | return alignment; | |
2493 | } | |
2494 | ||
2495 | ||
2496 | /* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in | |
ca557f44 AC |
2497 | place to be passed to a function, as specified by the "GNU/Linux |
2498 | for S/390 ELF Application Binary Interface Supplement". | |
78f8b424 JB |
2499 | |
2500 | SP is the current stack pointer. We must put arguments, links, | |
2501 | padding, etc. whereever they belong, and return the new stack | |
2502 | pointer value. | |
2503 | ||
2504 | If STRUCT_RETURN is non-zero, then the function we're calling is | |
2505 | going to return a structure by value; STRUCT_ADDR is the address of | |
2506 | a block we've allocated for it on the stack. | |
2507 | ||
2508 | Our caller has taken care of any type promotions needed to satisfy | |
2509 | prototypes or the old K&R argument-passing rules. */ | |
a78f21af | 2510 | static CORE_ADDR |
b0cf273e JB |
2511 | s390_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, |
2512 | struct regcache *regcache, CORE_ADDR bp_addr, | |
2513 | int nargs, struct value **args, CORE_ADDR sp, | |
2514 | int struct_return, CORE_ADDR struct_addr) | |
5769d3cd | 2515 | { |
b0cf273e JB |
2516 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
2517 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; | |
2518 | ULONGEST orig_sp; | |
78f8b424 | 2519 | int i; |
5769d3cd | 2520 | |
78f8b424 JB |
2521 | /* If the i'th argument is passed as a reference to a copy, then |
2522 | copy_addr[i] is the address of the copy we made. */ | |
2523 | CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR)); | |
5769d3cd | 2524 | |
78f8b424 | 2525 | /* Build the reference-to-copy area. */ |
78f8b424 JB |
2526 | for (i = 0; i < nargs; i++) |
2527 | { | |
2528 | struct value *arg = args[i]; | |
2529 | struct type *type = VALUE_TYPE (arg); | |
2530 | unsigned length = TYPE_LENGTH (type); | |
5769d3cd | 2531 | |
b0cf273e | 2532 | if (s390_function_arg_pass_by_reference (type)) |
01c464e9 | 2533 | { |
78f8b424 | 2534 | sp -= length; |
5b03f266 | 2535 | sp = align_down (sp, alignment_of (type)); |
78f8b424 JB |
2536 | write_memory (sp, VALUE_CONTENTS (arg), length); |
2537 | copy_addr[i] = sp; | |
01c464e9 | 2538 | } |
5769d3cd | 2539 | } |
5769d3cd | 2540 | |
78f8b424 JB |
2541 | /* Reserve space for the parameter area. As a conservative |
2542 | simplification, we assume that everything will be passed on the | |
b0cf273e JB |
2543 | stack. Since every argument larger than 8 bytes will be |
2544 | passed by reference, we use this simple upper bound. */ | |
2545 | sp -= nargs * 8; | |
78f8b424 | 2546 | |
78f8b424 JB |
2547 | /* After all that, make sure it's still aligned on an eight-byte |
2548 | boundary. */ | |
5b03f266 | 2549 | sp = align_down (sp, 8); |
78f8b424 JB |
2550 | |
2551 | /* Finally, place the actual parameters, working from SP towards | |
2552 | higher addresses. The code above is supposed to reserve enough | |
2553 | space for this. */ | |
2554 | { | |
2555 | int fr = 0; | |
2556 | int gr = 2; | |
2557 | CORE_ADDR starg = sp; | |
2558 | ||
b0cf273e | 2559 | /* A struct is returned using general register 2. */ |
4d819d0e | 2560 | if (struct_return) |
b0cf273e JB |
2561 | { |
2562 | regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr, | |
2563 | struct_addr); | |
2564 | gr++; | |
2565 | } | |
4d819d0e | 2566 | |
78f8b424 JB |
2567 | for (i = 0; i < nargs; i++) |
2568 | { | |
2569 | struct value *arg = args[i]; | |
2570 | struct type *type = VALUE_TYPE (arg); | |
b0cf273e JB |
2571 | unsigned length = TYPE_LENGTH (type); |
2572 | ||
2573 | if (s390_function_arg_pass_by_reference (type)) | |
2574 | { | |
2575 | if (gr <= 6) | |
2576 | { | |
2577 | regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr, | |
2578 | copy_addr[i]); | |
2579 | gr++; | |
2580 | } | |
2581 | else | |
2582 | { | |
2583 | write_memory_unsigned_integer (starg, word_size, copy_addr[i]); | |
2584 | starg += word_size; | |
2585 | } | |
2586 | } | |
2587 | else if (s390_function_arg_float (type)) | |
2588 | { | |
2589 | /* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass arguments, | |
2590 | the GNU/Linux for zSeries ABI uses 0, 2, 4, and 6. */ | |
2591 | if (fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6)) | |
2592 | { | |
2593 | /* When we store a single-precision value in an FP register, | |
2594 | it occupies the leftmost bits. */ | |
2595 | regcache_cooked_write_part (regcache, S390_F0_REGNUM + fr, | |
2596 | 0, length, VALUE_CONTENTS (arg)); | |
2597 | fr += 2; | |
2598 | } | |
2599 | else | |
2600 | { | |
2601 | /* When we store a single-precision value in a stack slot, | |
2602 | it occupies the rightmost bits. */ | |
2603 | starg = align_up (starg + length, word_size); | |
2604 | write_memory (starg - length, VALUE_CONTENTS (arg), length); | |
2605 | } | |
2606 | } | |
2607 | else if (s390_function_arg_integer (type) && length <= word_size) | |
2608 | { | |
2609 | if (gr <= 6) | |
2610 | { | |
2611 | /* Integer arguments are always extended to word size. */ | |
2612 | regcache_cooked_write_signed (regcache, S390_R0_REGNUM + gr, | |
2613 | extend_simple_arg (arg)); | |
2614 | gr++; | |
2615 | } | |
2616 | else | |
2617 | { | |
2618 | /* Integer arguments are always extended to word size. */ | |
2619 | write_memory_signed_integer (starg, word_size, | |
2620 | extend_simple_arg (arg)); | |
2621 | starg += word_size; | |
2622 | } | |
2623 | } | |
2624 | else if (s390_function_arg_integer (type) && length == 2*word_size) | |
2625 | { | |
2626 | if (gr <= 5) | |
2627 | { | |
2628 | regcache_cooked_write (regcache, S390_R0_REGNUM + gr, | |
2629 | VALUE_CONTENTS (arg)); | |
2630 | regcache_cooked_write (regcache, S390_R0_REGNUM + gr + 1, | |
2631 | VALUE_CONTENTS (arg) + word_size); | |
2632 | gr += 2; | |
2633 | } | |
2634 | else | |
2635 | { | |
2636 | /* If we skipped r6 because we couldn't fit a DOUBLE_ARG | |
2637 | in it, then don't go back and use it again later. */ | |
2638 | gr = 7; | |
2639 | ||
2640 | write_memory (starg, VALUE_CONTENTS (arg), length); | |
2641 | starg += length; | |
2642 | } | |
2643 | } | |
2644 | else | |
2645 | internal_error (__FILE__, __LINE__, "unknown argument type"); | |
78f8b424 JB |
2646 | } |
2647 | } | |
2648 | ||
2649 | /* Allocate the standard frame areas: the register save area, the | |
2650 | word reserved for the compiler (which seems kind of meaningless), | |
2651 | and the back chain pointer. */ | |
b0cf273e | 2652 | sp -= 16*word_size + 32; |
78f8b424 JB |
2653 | |
2654 | /* Write the back chain pointer into the first word of the stack | |
b0cf273e JB |
2655 | frame. This is needed to unwind across a dummy frame. */ |
2656 | regcache_cooked_read_unsigned (regcache, S390_SP_REGNUM, &orig_sp); | |
2657 | write_memory_unsigned_integer (sp, word_size, orig_sp); | |
2658 | ||
2659 | /* Store return address. */ | |
2660 | regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr); | |
2661 | ||
2662 | /* Store updated stack pointer. */ | |
2663 | regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, sp); | |
78f8b424 | 2664 | |
a8c99f38 JB |
2665 | /* We need to return the 'stack part' of the frame ID, |
2666 | which is actually the top of the register save area | |
2667 | allocated on the original stack. */ | |
2668 | return orig_sp + 16*word_size + 32; | |
5769d3cd AC |
2669 | } |
2670 | ||
b0cf273e JB |
2671 | /* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that |
2672 | dummy frame. The frame ID's base needs to match the TOS value | |
2673 | returned by push_dummy_call, and the PC match the dummy frame's | |
2674 | breakpoint. */ | |
2675 | static struct frame_id | |
2676 | s390_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
2677 | { | |
a8c99f38 JB |
2678 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
2679 | CORE_ADDR this_sp = s390_unwind_sp (gdbarch, next_frame); | |
2680 | CORE_ADDR prev_sp = read_memory_unsigned_integer (this_sp, word_size); | |
2681 | ||
2682 | return frame_id_build (prev_sp + 16*word_size + 32, | |
2683 | frame_pc_unwind (next_frame)); | |
b0cf273e | 2684 | } |
c8f9d51c | 2685 | |
4074e13c JB |
2686 | static CORE_ADDR |
2687 | s390_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr) | |
2688 | { | |
2689 | /* Both the 32- and 64-bit ABI's say that the stack pointer should | |
2690 | always be aligned on an eight-byte boundary. */ | |
2691 | return (addr & -8); | |
2692 | } | |
2693 | ||
2694 | ||
b0cf273e JB |
2695 | /* Function return value access. */ |
2696 | ||
2697 | static enum return_value_convention | |
2698 | s390_return_value_convention (struct gdbarch *gdbarch, struct type *type) | |
c8f9d51c | 2699 | { |
b0cf273e JB |
2700 | int length = TYPE_LENGTH (type); |
2701 | if (length > 8) | |
2702 | return RETURN_VALUE_STRUCT_CONVENTION; | |
2703 | ||
2704 | switch (TYPE_CODE (type)) | |
2705 | { | |
2706 | case TYPE_CODE_STRUCT: | |
2707 | case TYPE_CODE_UNION: | |
2708 | case TYPE_CODE_ARRAY: | |
2709 | return RETURN_VALUE_STRUCT_CONVENTION; | |
c8f9d51c | 2710 | |
b0cf273e JB |
2711 | default: |
2712 | return RETURN_VALUE_REGISTER_CONVENTION; | |
2713 | } | |
c8f9d51c JB |
2714 | } |
2715 | ||
b0cf273e JB |
2716 | static enum return_value_convention |
2717 | s390_return_value (struct gdbarch *gdbarch, struct type *type, | |
2718 | struct regcache *regcache, void *out, const void *in) | |
5769d3cd | 2719 | { |
b0cf273e JB |
2720 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
2721 | int length = TYPE_LENGTH (type); | |
2722 | enum return_value_convention rvc = | |
2723 | s390_return_value_convention (gdbarch, type); | |
2724 | if (in) | |
2725 | { | |
2726 | switch (rvc) | |
2727 | { | |
2728 | case RETURN_VALUE_REGISTER_CONVENTION: | |
2729 | if (TYPE_CODE (type) == TYPE_CODE_FLT) | |
2730 | { | |
2731 | /* When we store a single-precision value in an FP register, | |
2732 | it occupies the leftmost bits. */ | |
2733 | regcache_cooked_write_part (regcache, S390_F0_REGNUM, | |
2734 | 0, length, in); | |
2735 | } | |
2736 | else if (length <= word_size) | |
2737 | { | |
2738 | /* Integer arguments are always extended to word size. */ | |
2739 | if (TYPE_UNSIGNED (type)) | |
2740 | regcache_cooked_write_unsigned (regcache, S390_R2_REGNUM, | |
2741 | extract_unsigned_integer (in, length)); | |
2742 | else | |
2743 | regcache_cooked_write_signed (regcache, S390_R2_REGNUM, | |
2744 | extract_signed_integer (in, length)); | |
2745 | } | |
2746 | else if (length == 2*word_size) | |
2747 | { | |
2748 | regcache_cooked_write (regcache, S390_R2_REGNUM, in); | |
2749 | regcache_cooked_write (regcache, S390_R3_REGNUM, | |
2750 | (const char *)in + word_size); | |
2751 | } | |
2752 | else | |
2753 | internal_error (__FILE__, __LINE__, "invalid return type"); | |
2754 | break; | |
2755 | ||
2756 | case RETURN_VALUE_STRUCT_CONVENTION: | |
2757 | error ("Cannot set function return value."); | |
2758 | break; | |
2759 | } | |
2760 | } | |
2761 | else if (out) | |
2762 | { | |
2763 | switch (rvc) | |
2764 | { | |
2765 | case RETURN_VALUE_REGISTER_CONVENTION: | |
2766 | if (TYPE_CODE (type) == TYPE_CODE_FLT) | |
2767 | { | |
2768 | /* When we store a single-precision value in an FP register, | |
2769 | it occupies the leftmost bits. */ | |
2770 | regcache_cooked_read_part (regcache, S390_F0_REGNUM, | |
2771 | 0, length, out); | |
2772 | } | |
2773 | else if (length <= word_size) | |
2774 | { | |
2775 | /* Integer arguments occupy the rightmost bits. */ | |
2776 | regcache_cooked_read_part (regcache, S390_R2_REGNUM, | |
2777 | word_size - length, length, out); | |
2778 | } | |
2779 | else if (length == 2*word_size) | |
2780 | { | |
2781 | regcache_cooked_read (regcache, S390_R2_REGNUM, out); | |
2782 | regcache_cooked_read (regcache, S390_R3_REGNUM, | |
2783 | (char *)out + word_size); | |
2784 | } | |
2785 | else | |
2786 | internal_error (__FILE__, __LINE__, "invalid return type"); | |
2787 | break; | |
5769d3cd | 2788 | |
b0cf273e JB |
2789 | case RETURN_VALUE_STRUCT_CONVENTION: |
2790 | error ("Function return value unknown."); | |
2791 | break; | |
2792 | } | |
2793 | } | |
2794 | ||
2795 | return rvc; | |
2796 | } | |
5769d3cd AC |
2797 | |
2798 | ||
a8c99f38 JB |
2799 | /* Breakpoints. */ |
2800 | ||
a78f21af | 2801 | static const unsigned char * |
5769d3cd AC |
2802 | s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) |
2803 | { | |
2804 | static unsigned char breakpoint[] = { 0x0, 0x1 }; | |
2805 | ||
2806 | *lenptr = sizeof (breakpoint); | |
2807 | return breakpoint; | |
2808 | } | |
2809 | ||
5769d3cd | 2810 | |
a8c99f38 | 2811 | /* Address handling. */ |
5769d3cd AC |
2812 | |
2813 | static CORE_ADDR | |
2814 | s390_addr_bits_remove (CORE_ADDR addr) | |
2815 | { | |
a8c99f38 | 2816 | return addr & 0x7fffffff; |
5769d3cd AC |
2817 | } |
2818 | ||
ffc65945 KB |
2819 | static int |
2820 | s390_address_class_type_flags (int byte_size, int dwarf2_addr_class) | |
2821 | { | |
2822 | if (byte_size == 4) | |
2823 | return TYPE_FLAG_ADDRESS_CLASS_1; | |
2824 | else | |
2825 | return 0; | |
2826 | } | |
2827 | ||
2828 | static const char * | |
2829 | s390_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags) | |
2830 | { | |
2831 | if (type_flags & TYPE_FLAG_ADDRESS_CLASS_1) | |
2832 | return "mode32"; | |
2833 | else | |
2834 | return NULL; | |
2835 | } | |
2836 | ||
a78f21af | 2837 | static int |
ffc65945 KB |
2838 | s390_address_class_name_to_type_flags (struct gdbarch *gdbarch, const char *name, |
2839 | int *type_flags_ptr) | |
2840 | { | |
2841 | if (strcmp (name, "mode32") == 0) | |
2842 | { | |
2843 | *type_flags_ptr = TYPE_FLAG_ADDRESS_CLASS_1; | |
2844 | return 1; | |
2845 | } | |
2846 | else | |
2847 | return 0; | |
2848 | } | |
2849 | ||
a8c99f38 JB |
2850 | |
2851 | /* Set up gdbarch struct. */ | |
2852 | ||
a78f21af | 2853 | static struct gdbarch * |
5769d3cd AC |
2854 | s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
2855 | { | |
5769d3cd AC |
2856 | struct gdbarch *gdbarch; |
2857 | struct gdbarch_tdep *tdep; | |
5769d3cd AC |
2858 | |
2859 | /* First see if there is already a gdbarch that can satisfy the request. */ | |
2860 | arches = gdbarch_list_lookup_by_info (arches, &info); | |
2861 | if (arches != NULL) | |
2862 | return arches->gdbarch; | |
2863 | ||
2864 | /* None found: is the request for a s390 architecture? */ | |
2865 | if (info.bfd_arch_info->arch != bfd_arch_s390) | |
2866 | return NULL; /* No; then it's not for us. */ | |
2867 | ||
2868 | /* Yes: create a new gdbarch for the specified machine type. */ | |
d0f54f9d JB |
2869 | tdep = XCALLOC (1, struct gdbarch_tdep); |
2870 | gdbarch = gdbarch_alloc (&info, tdep); | |
5769d3cd AC |
2871 | |
2872 | set_gdbarch_believe_pcc_promotion (gdbarch, 0); | |
4e409299 | 2873 | set_gdbarch_char_signed (gdbarch, 0); |
5769d3cd | 2874 | |
aaab4dba AC |
2875 | /* Amount PC must be decremented by after a breakpoint. This is |
2876 | often the number of bytes returned by BREAKPOINT_FROM_PC but not | |
2877 | always. */ | |
5769d3cd | 2878 | set_gdbarch_decr_pc_after_break (gdbarch, 2); |
5769d3cd AC |
2879 | /* Stack grows downward. */ |
2880 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); | |
5769d3cd AC |
2881 | set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc); |
2882 | set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue); | |
d0f54f9d | 2883 | set_gdbarch_in_function_epilogue_p (gdbarch, s390_in_function_epilogue_p); |
a8c99f38 | 2884 | |
5769d3cd AC |
2885 | set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM); |
2886 | set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM); | |
d0f54f9d | 2887 | set_gdbarch_fp0_regnum (gdbarch, S390_F0_REGNUM); |
5769d3cd | 2888 | set_gdbarch_num_regs (gdbarch, S390_NUM_REGS); |
d0f54f9d | 2889 | set_gdbarch_num_pseudo_regs (gdbarch, S390_NUM_PSEUDO_REGS); |
5769d3cd | 2890 | set_gdbarch_register_name (gdbarch, s390_register_name); |
d0f54f9d JB |
2891 | set_gdbarch_register_type (gdbarch, s390_register_type); |
2892 | set_gdbarch_stab_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); | |
2893 | set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); | |
2894 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); | |
2895 | set_gdbarch_convert_register_p (gdbarch, s390_convert_register_p); | |
2896 | set_gdbarch_register_to_value (gdbarch, s390_register_to_value); | |
2897 | set_gdbarch_value_to_register (gdbarch, s390_value_to_register); | |
2898 | set_gdbarch_register_reggroup_p (gdbarch, s390_register_reggroup_p); | |
2899 | set_gdbarch_regset_from_core_section (gdbarch, | |
2900 | s390_regset_from_core_section); | |
5769d3cd | 2901 | |
b0cf273e JB |
2902 | /* Inferior function calls. */ |
2903 | set_gdbarch_push_dummy_call (gdbarch, s390_push_dummy_call); | |
2904 | set_gdbarch_unwind_dummy_id (gdbarch, s390_unwind_dummy_id); | |
4074e13c | 2905 | set_gdbarch_frame_align (gdbarch, s390_frame_align); |
b0cf273e | 2906 | set_gdbarch_return_value (gdbarch, s390_return_value); |
5769d3cd | 2907 | |
a8c99f38 JB |
2908 | /* Frame handling. */ |
2909 | set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); | |
2910 | frame_unwind_append_sniffer (gdbarch, s390_pltstub_frame_sniffer); | |
2911 | frame_unwind_append_sniffer (gdbarch, s390_sigtramp_frame_sniffer); | |
2912 | frame_unwind_append_sniffer (gdbarch, s390_frame_sniffer); | |
2913 | frame_base_set_default (gdbarch, &s390_frame_base); | |
2914 | set_gdbarch_unwind_pc (gdbarch, s390_unwind_pc); | |
2915 | set_gdbarch_unwind_sp (gdbarch, s390_unwind_sp); | |
2916 | ||
5769d3cd AC |
2917 | switch (info.bfd_arch_info->mach) |
2918 | { | |
b8b8b047 | 2919 | case bfd_mach_s390_31: |
b0cf273e JB |
2920 | tdep->abi = ABI_LINUX_S390; |
2921 | ||
d0f54f9d JB |
2922 | tdep->gregset = &s390_gregset; |
2923 | tdep->sizeof_gregset = s390_sizeof_gregset; | |
2924 | tdep->fpregset = &s390_fpregset; | |
2925 | tdep->sizeof_fpregset = s390_sizeof_fpregset; | |
5769d3cd AC |
2926 | |
2927 | set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove); | |
d0f54f9d JB |
2928 | set_gdbarch_pseudo_register_read (gdbarch, s390_pseudo_register_read); |
2929 | set_gdbarch_pseudo_register_write (gdbarch, s390_pseudo_register_write); | |
5769d3cd | 2930 | break; |
b8b8b047 | 2931 | case bfd_mach_s390_64: |
b0cf273e JB |
2932 | tdep->abi = ABI_LINUX_ZSERIES; |
2933 | ||
d0f54f9d JB |
2934 | tdep->gregset = &s390x_gregset; |
2935 | tdep->sizeof_gregset = s390x_sizeof_gregset; | |
2936 | tdep->fpregset = &s390_fpregset; | |
2937 | tdep->sizeof_fpregset = s390_sizeof_fpregset; | |
5769d3cd AC |
2938 | |
2939 | set_gdbarch_long_bit (gdbarch, 64); | |
2940 | set_gdbarch_long_long_bit (gdbarch, 64); | |
2941 | set_gdbarch_ptr_bit (gdbarch, 64); | |
d0f54f9d JB |
2942 | set_gdbarch_pseudo_register_read (gdbarch, s390x_pseudo_register_read); |
2943 | set_gdbarch_pseudo_register_write (gdbarch, s390x_pseudo_register_write); | |
ffc65945 KB |
2944 | set_gdbarch_address_class_type_flags (gdbarch, |
2945 | s390_address_class_type_flags); | |
2946 | set_gdbarch_address_class_type_flags_to_name (gdbarch, | |
2947 | s390_address_class_type_flags_to_name); | |
2948 | set_gdbarch_address_class_name_to_type_flags (gdbarch, | |
2949 | s390_address_class_name_to_type_flags); | |
5769d3cd AC |
2950 | break; |
2951 | } | |
2952 | ||
36482093 AC |
2953 | set_gdbarch_print_insn (gdbarch, print_insn_s390); |
2954 | ||
5769d3cd AC |
2955 | return gdbarch; |
2956 | } | |
2957 | ||
2958 | ||
2959 | ||
a78f21af AC |
2960 | extern initialize_file_ftype _initialize_s390_tdep; /* -Wmissing-prototypes */ |
2961 | ||
5769d3cd | 2962 | void |
5ae5f592 | 2963 | _initialize_s390_tdep (void) |
5769d3cd AC |
2964 | { |
2965 | ||
2966 | /* Hook us into the gdbarch mechanism. */ | |
2967 | register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init); | |
5769d3cd | 2968 | } |