Commit | Line | Data |
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1f82754b JB |
1 | /* Native support code for PPC AIX, for GDB the GNU debugger. |
2 | ||
28e7fd62 | 3 | Copyright (C) 2006-2013 Free Software Foundation, Inc. |
1f82754b JB |
4 | |
5 | Free Software Foundation, Inc. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
1f82754b JB |
12 | (at your option) any later version. |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
1f82754b JB |
21 | |
22 | #include "defs.h" | |
7a61a01c | 23 | #include "gdb_string.h" |
4a7622d1 | 24 | #include "gdb_assert.h" |
1f82754b | 25 | #include "osabi.h" |
7a61a01c UW |
26 | #include "regcache.h" |
27 | #include "regset.h" | |
4a7622d1 UW |
28 | #include "gdbtypes.h" |
29 | #include "gdbcore.h" | |
30 | #include "target.h" | |
31 | #include "value.h" | |
32 | #include "infcall.h" | |
33 | #include "objfiles.h" | |
34 | #include "breakpoint.h" | |
1f82754b | 35 | #include "rs6000-tdep.h" |
6f7f3f0d | 36 | #include "ppc-tdep.h" |
2971b56b | 37 | #include "exceptions.h" |
d5367fe1 | 38 | #include "xcoffread.h" |
4d1eb6b4 JB |
39 | #include "solib.h" |
40 | #include "solib-aix.h" | |
4a7622d1 UW |
41 | |
42 | /* If the kernel has to deliver a signal, it pushes a sigcontext | |
43 | structure on the stack and then calls the signal handler, passing | |
0df8b418 | 44 | the address of the sigcontext in an argument register. Usually |
4a7622d1 UW |
45 | the signal handler doesn't save this register, so we have to |
46 | access the sigcontext structure via an offset from the signal handler | |
47 | frame. | |
48 | The following constants were determined by experimentation on AIX 3.2. */ | |
49 | #define SIG_FRAME_PC_OFFSET 96 | |
50 | #define SIG_FRAME_LR_OFFSET 108 | |
51 | #define SIG_FRAME_FP_OFFSET 284 | |
52 | ||
7a61a01c UW |
53 | |
54 | /* Core file support. */ | |
55 | ||
56 | static struct ppc_reg_offsets rs6000_aix32_reg_offsets = | |
57 | { | |
58 | /* General-purpose registers. */ | |
59 | 208, /* r0_offset */ | |
f2db237a AM |
60 | 4, /* gpr_size */ |
61 | 4, /* xr_size */ | |
7a61a01c UW |
62 | 24, /* pc_offset */ |
63 | 28, /* ps_offset */ | |
64 | 32, /* cr_offset */ | |
65 | 36, /* lr_offset */ | |
66 | 40, /* ctr_offset */ | |
67 | 44, /* xer_offset */ | |
68 | 48, /* mq_offset */ | |
69 | ||
70 | /* Floating-point registers. */ | |
71 | 336, /* f0_offset */ | |
72 | 56, /* fpscr_offset */ | |
f2db237a | 73 | 4, /* fpscr_size */ |
7a61a01c UW |
74 | |
75 | /* AltiVec registers. */ | |
76 | -1, /* vr0_offset */ | |
77 | -1, /* vscr_offset */ | |
78 | -1 /* vrsave_offset */ | |
79 | }; | |
80 | ||
81 | static struct ppc_reg_offsets rs6000_aix64_reg_offsets = | |
82 | { | |
83 | /* General-purpose registers. */ | |
84 | 0, /* r0_offset */ | |
f2db237a AM |
85 | 8, /* gpr_size */ |
86 | 4, /* xr_size */ | |
7a61a01c UW |
87 | 264, /* pc_offset */ |
88 | 256, /* ps_offset */ | |
89 | 288, /* cr_offset */ | |
90 | 272, /* lr_offset */ | |
91 | 280, /* ctr_offset */ | |
92 | 292, /* xer_offset */ | |
93 | -1, /* mq_offset */ | |
94 | ||
95 | /* Floating-point registers. */ | |
96 | 312, /* f0_offset */ | |
97 | 296, /* fpscr_offset */ | |
f2db237a | 98 | 4, /* fpscr_size */ |
7a61a01c UW |
99 | |
100 | /* AltiVec registers. */ | |
101 | -1, /* vr0_offset */ | |
102 | -1, /* vscr_offset */ | |
103 | -1 /* vrsave_offset */ | |
104 | }; | |
105 | ||
106 | ||
107 | /* Supply register REGNUM in the general-purpose register set REGSET | |
108 | from the buffer specified by GREGS and LEN to register cache | |
109 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ | |
110 | ||
111 | static void | |
112 | rs6000_aix_supply_regset (const struct regset *regset, | |
113 | struct regcache *regcache, int regnum, | |
114 | const void *gregs, size_t len) | |
115 | { | |
116 | ppc_supply_gregset (regset, regcache, regnum, gregs, len); | |
f2db237a | 117 | ppc_supply_fpregset (regset, regcache, regnum, gregs, len); |
7a61a01c UW |
118 | } |
119 | ||
120 | /* Collect register REGNUM in the general-purpose register set | |
0df8b418 | 121 | REGSET, from register cache REGCACHE into the buffer specified by |
7a61a01c UW |
122 | GREGS and LEN. If REGNUM is -1, do this for all registers in |
123 | REGSET. */ | |
124 | ||
125 | static void | |
126 | rs6000_aix_collect_regset (const struct regset *regset, | |
127 | const struct regcache *regcache, int regnum, | |
128 | void *gregs, size_t len) | |
129 | { | |
130 | ppc_collect_gregset (regset, regcache, regnum, gregs, len); | |
f2db237a | 131 | ppc_collect_fpregset (regset, regcache, regnum, gregs, len); |
7a61a01c UW |
132 | } |
133 | ||
134 | /* AIX register set. */ | |
135 | ||
136 | static struct regset rs6000_aix32_regset = | |
137 | { | |
138 | &rs6000_aix32_reg_offsets, | |
139 | rs6000_aix_supply_regset, | |
140 | rs6000_aix_collect_regset, | |
141 | }; | |
142 | ||
143 | static struct regset rs6000_aix64_regset = | |
144 | { | |
145 | &rs6000_aix64_reg_offsets, | |
146 | rs6000_aix_supply_regset, | |
147 | rs6000_aix_collect_regset, | |
148 | }; | |
149 | ||
150 | /* Return the appropriate register set for the core section identified | |
151 | by SECT_NAME and SECT_SIZE. */ | |
152 | ||
153 | static const struct regset * | |
154 | rs6000_aix_regset_from_core_section (struct gdbarch *gdbarch, | |
155 | const char *sect_name, size_t sect_size) | |
156 | { | |
157 | if (gdbarch_tdep (gdbarch)->wordsize == 4) | |
158 | { | |
159 | if (strcmp (sect_name, ".reg") == 0 && sect_size >= 592) | |
160 | return &rs6000_aix32_regset; | |
161 | } | |
162 | else | |
163 | { | |
164 | if (strcmp (sect_name, ".reg") == 0 && sect_size >= 576) | |
165 | return &rs6000_aix64_regset; | |
166 | } | |
167 | ||
168 | return NULL; | |
169 | } | |
170 | ||
171 | ||
0df8b418 | 172 | /* Pass the arguments in either registers, or in the stack. In RS/6000, |
4a7622d1 UW |
173 | the first eight words of the argument list (that might be less than |
174 | eight parameters if some parameters occupy more than one word) are | |
0df8b418 | 175 | passed in r3..r10 registers. Float and double parameters are |
4a7622d1 UW |
176 | passed in fpr's, in addition to that. Rest of the parameters if any |
177 | are passed in user stack. There might be cases in which half of the | |
178 | parameter is copied into registers, the other half is pushed into | |
179 | stack. | |
180 | ||
181 | Stack must be aligned on 64-bit boundaries when synthesizing | |
182 | function calls. | |
183 | ||
184 | If the function is returning a structure, then the return address is passed | |
185 | in r3, then the first 7 words of the parameters can be passed in registers, | |
186 | starting from r4. */ | |
187 | ||
188 | static CORE_ADDR | |
189 | rs6000_push_dummy_call (struct gdbarch *gdbarch, struct value *function, | |
190 | struct regcache *regcache, CORE_ADDR bp_addr, | |
191 | int nargs, struct value **args, CORE_ADDR sp, | |
192 | int struct_return, CORE_ADDR struct_addr) | |
193 | { | |
194 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
e17a4113 | 195 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
4a7622d1 UW |
196 | int ii; |
197 | int len = 0; | |
198 | int argno; /* current argument number */ | |
199 | int argbytes; /* current argument byte */ | |
200 | gdb_byte tmp_buffer[50]; | |
201 | int f_argno = 0; /* current floating point argno */ | |
202 | int wordsize = gdbarch_tdep (gdbarch)->wordsize; | |
203 | CORE_ADDR func_addr = find_function_addr (function, NULL); | |
204 | ||
205 | struct value *arg = 0; | |
206 | struct type *type; | |
207 | ||
208 | ULONGEST saved_sp; | |
209 | ||
210 | /* The calling convention this function implements assumes the | |
211 | processor has floating-point registers. We shouldn't be using it | |
212 | on PPC variants that lack them. */ | |
213 | gdb_assert (ppc_floating_point_unit_p (gdbarch)); | |
214 | ||
215 | /* The first eight words of ther arguments are passed in registers. | |
216 | Copy them appropriately. */ | |
217 | ii = 0; | |
218 | ||
219 | /* If the function is returning a `struct', then the first word | |
220 | (which will be passed in r3) is used for struct return address. | |
221 | In that case we should advance one word and start from r4 | |
222 | register to copy parameters. */ | |
223 | if (struct_return) | |
224 | { | |
225 | regcache_raw_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3, | |
226 | struct_addr); | |
227 | ii++; | |
228 | } | |
229 | ||
0df8b418 | 230 | /* effectively indirect call... gcc does... |
4a7622d1 UW |
231 | |
232 | return_val example( float, int); | |
233 | ||
234 | eabi: | |
235 | float in fp0, int in r3 | |
236 | offset of stack on overflow 8/16 | |
237 | for varargs, must go by type. | |
238 | power open: | |
239 | float in r3&r4, int in r5 | |
240 | offset of stack on overflow different | |
241 | both: | |
242 | return in r3 or f0. If no float, must study how gcc emulates floats; | |
0df8b418 | 243 | pay attention to arg promotion. |
4a7622d1 | 244 | User may have to cast\args to handle promotion correctly |
0df8b418 | 245 | since gdb won't know if prototype supplied or not. */ |
4a7622d1 UW |
246 | |
247 | for (argno = 0, argbytes = 0; argno < nargs && ii < 8; ++ii) | |
248 | { | |
249 | int reg_size = register_size (gdbarch, ii + 3); | |
250 | ||
251 | arg = args[argno]; | |
252 | type = check_typedef (value_type (arg)); | |
253 | len = TYPE_LENGTH (type); | |
254 | ||
255 | if (TYPE_CODE (type) == TYPE_CODE_FLT) | |
256 | { | |
257 | ||
258 | /* Floating point arguments are passed in fpr's, as well as gpr's. | |
0df8b418 | 259 | There are 13 fpr's reserved for passing parameters. At this point |
4a7622d1 UW |
260 | there is no way we would run out of them. */ |
261 | ||
262 | gdb_assert (len <= 8); | |
263 | ||
264 | regcache_cooked_write (regcache, | |
265 | tdep->ppc_fp0_regnum + 1 + f_argno, | |
266 | value_contents (arg)); | |
267 | ++f_argno; | |
268 | } | |
269 | ||
270 | if (len > reg_size) | |
271 | { | |
272 | ||
273 | /* Argument takes more than one register. */ | |
274 | while (argbytes < len) | |
275 | { | |
276 | gdb_byte word[MAX_REGISTER_SIZE]; | |
277 | memset (word, 0, reg_size); | |
278 | memcpy (word, | |
279 | ((char *) value_contents (arg)) + argbytes, | |
280 | (len - argbytes) > reg_size | |
281 | ? reg_size : len - argbytes); | |
282 | regcache_cooked_write (regcache, | |
283 | tdep->ppc_gp0_regnum + 3 + ii, | |
284 | word); | |
285 | ++ii, argbytes += reg_size; | |
286 | ||
287 | if (ii >= 8) | |
288 | goto ran_out_of_registers_for_arguments; | |
289 | } | |
290 | argbytes = 0; | |
291 | --ii; | |
292 | } | |
293 | else | |
294 | { | |
295 | /* Argument can fit in one register. No problem. */ | |
296 | int adj = gdbarch_byte_order (gdbarch) | |
297 | == BFD_ENDIAN_BIG ? reg_size - len : 0; | |
298 | gdb_byte word[MAX_REGISTER_SIZE]; | |
299 | ||
300 | memset (word, 0, reg_size); | |
301 | memcpy (word, value_contents (arg), len); | |
302 | regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3 +ii, word); | |
303 | } | |
304 | ++argno; | |
305 | } | |
306 | ||
307 | ran_out_of_registers_for_arguments: | |
308 | ||
309 | regcache_cooked_read_unsigned (regcache, | |
310 | gdbarch_sp_regnum (gdbarch), | |
311 | &saved_sp); | |
312 | ||
313 | /* Location for 8 parameters are always reserved. */ | |
314 | sp -= wordsize * 8; | |
315 | ||
316 | /* Another six words for back chain, TOC register, link register, etc. */ | |
317 | sp -= wordsize * 6; | |
318 | ||
319 | /* Stack pointer must be quadword aligned. */ | |
320 | sp &= -16; | |
321 | ||
322 | /* If there are more arguments, allocate space for them in | |
323 | the stack, then push them starting from the ninth one. */ | |
324 | ||
325 | if ((argno < nargs) || argbytes) | |
326 | { | |
327 | int space = 0, jj; | |
328 | ||
329 | if (argbytes) | |
330 | { | |
331 | space += ((len - argbytes + 3) & -4); | |
332 | jj = argno + 1; | |
333 | } | |
334 | else | |
335 | jj = argno; | |
336 | ||
337 | for (; jj < nargs; ++jj) | |
338 | { | |
339 | struct value *val = args[jj]; | |
340 | space += ((TYPE_LENGTH (value_type (val))) + 3) & -4; | |
341 | } | |
342 | ||
343 | /* Add location required for the rest of the parameters. */ | |
344 | space = (space + 15) & -16; | |
345 | sp -= space; | |
346 | ||
347 | /* This is another instance we need to be concerned about | |
0df8b418 | 348 | securing our stack space. If we write anything underneath %sp |
4a7622d1 UW |
349 | (r1), we might conflict with the kernel who thinks he is free |
350 | to use this area. So, update %sp first before doing anything | |
351 | else. */ | |
352 | ||
353 | regcache_raw_write_signed (regcache, | |
354 | gdbarch_sp_regnum (gdbarch), sp); | |
355 | ||
356 | /* If the last argument copied into the registers didn't fit there | |
357 | completely, push the rest of it into stack. */ | |
358 | ||
359 | if (argbytes) | |
360 | { | |
361 | write_memory (sp + 24 + (ii * 4), | |
362 | value_contents (arg) + argbytes, | |
363 | len - argbytes); | |
364 | ++argno; | |
365 | ii += ((len - argbytes + 3) & -4) / 4; | |
366 | } | |
367 | ||
368 | /* Push the rest of the arguments into stack. */ | |
369 | for (; argno < nargs; ++argno) | |
370 | { | |
371 | ||
372 | arg = args[argno]; | |
373 | type = check_typedef (value_type (arg)); | |
374 | len = TYPE_LENGTH (type); | |
375 | ||
376 | ||
377 | /* Float types should be passed in fpr's, as well as in the | |
378 | stack. */ | |
379 | if (TYPE_CODE (type) == TYPE_CODE_FLT && f_argno < 13) | |
380 | { | |
381 | ||
382 | gdb_assert (len <= 8); | |
383 | ||
384 | regcache_cooked_write (regcache, | |
385 | tdep->ppc_fp0_regnum + 1 + f_argno, | |
386 | value_contents (arg)); | |
387 | ++f_argno; | |
388 | } | |
389 | ||
390 | write_memory (sp + 24 + (ii * 4), value_contents (arg), len); | |
391 | ii += ((len + 3) & -4) / 4; | |
392 | } | |
393 | } | |
394 | ||
395 | /* Set the stack pointer. According to the ABI, the SP is meant to | |
396 | be set _before_ the corresponding stack space is used. On AIX, | |
397 | this even applies when the target has been completely stopped! | |
398 | Not doing this can lead to conflicts with the kernel which thinks | |
399 | that it still has control over this not-yet-allocated stack | |
400 | region. */ | |
401 | regcache_raw_write_signed (regcache, gdbarch_sp_regnum (gdbarch), sp); | |
402 | ||
403 | /* Set back chain properly. */ | |
e17a4113 | 404 | store_unsigned_integer (tmp_buffer, wordsize, byte_order, saved_sp); |
4a7622d1 UW |
405 | write_memory (sp, tmp_buffer, wordsize); |
406 | ||
407 | /* Point the inferior function call's return address at the dummy's | |
408 | breakpoint. */ | |
409 | regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr); | |
410 | ||
4d1eb6b4 JB |
411 | /* Set the TOC register value. */ |
412 | regcache_raw_write_signed (regcache, tdep->ppc_toc_regnum, | |
413 | solib_aix_get_toc_value (func_addr)); | |
4a7622d1 UW |
414 | |
415 | target_store_registers (regcache, -1); | |
416 | return sp; | |
417 | } | |
418 | ||
419 | static enum return_value_convention | |
6a3a010b | 420 | rs6000_return_value (struct gdbarch *gdbarch, struct value *function, |
4a7622d1 UW |
421 | struct type *valtype, struct regcache *regcache, |
422 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
423 | { | |
424 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
e17a4113 | 425 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
4a7622d1 UW |
426 | |
427 | /* The calling convention this function implements assumes the | |
428 | processor has floating-point registers. We shouldn't be using it | |
429 | on PowerPC variants that lack them. */ | |
430 | gdb_assert (ppc_floating_point_unit_p (gdbarch)); | |
431 | ||
432 | /* AltiVec extension: Functions that declare a vector data type as a | |
433 | return value place that return value in VR2. */ | |
434 | if (TYPE_CODE (valtype) == TYPE_CODE_ARRAY && TYPE_VECTOR (valtype) | |
435 | && TYPE_LENGTH (valtype) == 16) | |
436 | { | |
437 | if (readbuf) | |
438 | regcache_cooked_read (regcache, tdep->ppc_vr0_regnum + 2, readbuf); | |
439 | if (writebuf) | |
440 | regcache_cooked_write (regcache, tdep->ppc_vr0_regnum + 2, writebuf); | |
441 | ||
442 | return RETURN_VALUE_REGISTER_CONVENTION; | |
443 | } | |
444 | ||
445 | /* If the called subprogram returns an aggregate, there exists an | |
446 | implicit first argument, whose value is the address of a caller- | |
447 | allocated buffer into which the callee is assumed to store its | |
0df8b418 | 448 | return value. All explicit parameters are appropriately |
4a7622d1 UW |
449 | relabeled. */ |
450 | if (TYPE_CODE (valtype) == TYPE_CODE_STRUCT | |
451 | || TYPE_CODE (valtype) == TYPE_CODE_UNION | |
452 | || TYPE_CODE (valtype) == TYPE_CODE_ARRAY) | |
453 | return RETURN_VALUE_STRUCT_CONVENTION; | |
454 | ||
455 | /* Scalar floating-point values are returned in FPR1 for float or | |
456 | double, and in FPR1:FPR2 for quadword precision. Fortran | |
457 | complex*8 and complex*16 are returned in FPR1:FPR2, and | |
458 | complex*32 is returned in FPR1:FPR4. */ | |
459 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT | |
460 | && (TYPE_LENGTH (valtype) == 4 || TYPE_LENGTH (valtype) == 8)) | |
461 | { | |
462 | struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum); | |
463 | gdb_byte regval[8]; | |
464 | ||
465 | /* FIXME: kettenis/2007-01-01: Add support for quadword | |
466 | precision and complex. */ | |
467 | ||
468 | if (readbuf) | |
469 | { | |
470 | regcache_cooked_read (regcache, tdep->ppc_fp0_regnum + 1, regval); | |
471 | convert_typed_floating (regval, regtype, readbuf, valtype); | |
472 | } | |
473 | if (writebuf) | |
474 | { | |
475 | convert_typed_floating (writebuf, valtype, regval, regtype); | |
476 | regcache_cooked_write (regcache, tdep->ppc_fp0_regnum + 1, regval); | |
477 | } | |
478 | ||
479 | return RETURN_VALUE_REGISTER_CONVENTION; | |
480 | } | |
481 | ||
482 | /* Values of the types int, long, short, pointer, and char (length | |
483 | is less than or equal to four bytes), as well as bit values of | |
484 | lengths less than or equal to 32 bits, must be returned right | |
485 | justified in GPR3 with signed values sign extended and unsigned | |
486 | values zero extended, as necessary. */ | |
487 | if (TYPE_LENGTH (valtype) <= tdep->wordsize) | |
488 | { | |
489 | if (readbuf) | |
490 | { | |
491 | ULONGEST regval; | |
492 | ||
493 | /* For reading we don't have to worry about sign extension. */ | |
494 | regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3, | |
495 | ®val); | |
e17a4113 UW |
496 | store_unsigned_integer (readbuf, TYPE_LENGTH (valtype), byte_order, |
497 | regval); | |
4a7622d1 UW |
498 | } |
499 | if (writebuf) | |
500 | { | |
501 | /* For writing, use unpack_long since that should handle any | |
502 | required sign extension. */ | |
503 | regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3, | |
504 | unpack_long (valtype, writebuf)); | |
505 | } | |
506 | ||
507 | return RETURN_VALUE_REGISTER_CONVENTION; | |
508 | } | |
509 | ||
510 | /* Eight-byte non-floating-point scalar values must be returned in | |
511 | GPR3:GPR4. */ | |
512 | ||
513 | if (TYPE_LENGTH (valtype) == 8) | |
514 | { | |
515 | gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_FLT); | |
516 | gdb_assert (tdep->wordsize == 4); | |
517 | ||
518 | if (readbuf) | |
519 | { | |
520 | gdb_byte regval[8]; | |
521 | ||
522 | regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 3, regval); | |
523 | regcache_cooked_read (regcache, tdep->ppc_gp0_regnum + 4, | |
524 | regval + 4); | |
525 | memcpy (readbuf, regval, 8); | |
526 | } | |
527 | if (writebuf) | |
528 | { | |
529 | regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 3, writebuf); | |
530 | regcache_cooked_write (regcache, tdep->ppc_gp0_regnum + 4, | |
531 | writebuf + 4); | |
532 | } | |
533 | ||
534 | return RETURN_VALUE_REGISTER_CONVENTION; | |
535 | } | |
536 | ||
537 | return RETURN_VALUE_STRUCT_CONVENTION; | |
538 | } | |
539 | ||
540 | /* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG). | |
541 | ||
542 | Usually a function pointer's representation is simply the address | |
0df8b418 MS |
543 | of the function. On the RS/6000 however, a function pointer is |
544 | represented by a pointer to an OPD entry. This OPD entry contains | |
4a7622d1 UW |
545 | three words, the first word is the address of the function, the |
546 | second word is the TOC pointer (r2), and the third word is the | |
547 | static chain value. Throughout GDB it is currently assumed that a | |
548 | function pointer contains the address of the function, which is not | |
549 | easy to fix. In addition, the conversion of a function address to | |
550 | a function pointer would require allocation of an OPD entry in the | |
551 | inferior's memory space, with all its drawbacks. To be able to | |
552 | call C++ virtual methods in the inferior (which are called via | |
553 | function pointers), find_function_addr uses this function to get the | |
554 | function address from a function pointer. */ | |
555 | ||
556 | /* Return real function address if ADDR (a function pointer) is in the data | |
557 | space and is therefore a special function pointer. */ | |
558 | ||
559 | static CORE_ADDR | |
560 | rs6000_convert_from_func_ptr_addr (struct gdbarch *gdbarch, | |
561 | CORE_ADDR addr, | |
562 | struct target_ops *targ) | |
563 | { | |
e17a4113 UW |
564 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
565 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
4a7622d1 UW |
566 | struct obj_section *s; |
567 | ||
568 | s = find_pc_section (addr); | |
4a7622d1 | 569 | |
40adab56 JB |
570 | /* Normally, functions live inside a section that is executable. |
571 | So, if ADDR points to a non-executable section, then treat it | |
572 | as a function descriptor and return the target address iff | |
573 | the target address itself points to a section that is executable. */ | |
574 | if (s && (s->the_bfd_section->flags & SEC_CODE) == 0) | |
575 | { | |
57174f31 | 576 | CORE_ADDR pc = 0; |
2971b56b | 577 | struct obj_section *pc_section; |
bfd189b1 | 578 | volatile struct gdb_exception e; |
2971b56b JB |
579 | |
580 | TRY_CATCH (e, RETURN_MASK_ERROR) | |
581 | { | |
582 | pc = read_memory_unsigned_integer (addr, tdep->wordsize, byte_order); | |
583 | } | |
584 | if (e.reason < 0) | |
585 | { | |
586 | /* An error occured during reading. Probably a memory error | |
587 | due to the section not being loaded yet. This address | |
588 | cannot be a function descriptor. */ | |
589 | return addr; | |
590 | } | |
591 | pc_section = find_pc_section (pc); | |
40adab56 JB |
592 | |
593 | if (pc_section && (pc_section->the_bfd_section->flags & SEC_CODE)) | |
594 | return pc; | |
595 | } | |
596 | ||
597 | return addr; | |
4a7622d1 UW |
598 | } |
599 | ||
600 | ||
601 | /* Calculate the destination of a branch/jump. Return -1 if not a branch. */ | |
602 | ||
603 | static CORE_ADDR | |
604 | branch_dest (struct frame_info *frame, int opcode, int instr, | |
605 | CORE_ADDR pc, CORE_ADDR safety) | |
606 | { | |
e17a4113 UW |
607 | struct gdbarch *gdbarch = get_frame_arch (frame); |
608 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
609 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
4a7622d1 UW |
610 | CORE_ADDR dest; |
611 | int immediate; | |
612 | int absolute; | |
613 | int ext_op; | |
614 | ||
615 | absolute = (int) ((instr >> 1) & 1); | |
616 | ||
617 | switch (opcode) | |
618 | { | |
619 | case 18: | |
620 | immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */ | |
621 | if (absolute) | |
622 | dest = immediate; | |
623 | else | |
624 | dest = pc + immediate; | |
625 | break; | |
626 | ||
627 | case 16: | |
628 | immediate = ((instr & ~3) << 16) >> 16; /* br conditional */ | |
629 | if (absolute) | |
630 | dest = immediate; | |
631 | else | |
632 | dest = pc + immediate; | |
633 | break; | |
634 | ||
635 | case 19: | |
636 | ext_op = (instr >> 1) & 0x3ff; | |
637 | ||
638 | if (ext_op == 16) /* br conditional register */ | |
639 | { | |
640 | dest = get_frame_register_unsigned (frame, tdep->ppc_lr_regnum) & ~3; | |
641 | ||
642 | /* If we are about to return from a signal handler, dest is | |
643 | something like 0x3c90. The current frame is a signal handler | |
644 | caller frame, upon completion of the sigreturn system call | |
645 | execution will return to the saved PC in the frame. */ | |
646 | if (dest < AIX_TEXT_SEGMENT_BASE) | |
647 | dest = read_memory_unsigned_integer | |
648 | (get_frame_base (frame) + SIG_FRAME_PC_OFFSET, | |
e17a4113 | 649 | tdep->wordsize, byte_order); |
4a7622d1 UW |
650 | } |
651 | ||
652 | else if (ext_op == 528) /* br cond to count reg */ | |
653 | { | |
0df8b418 MS |
654 | dest = get_frame_register_unsigned (frame, |
655 | tdep->ppc_ctr_regnum) & ~3; | |
4a7622d1 UW |
656 | |
657 | /* If we are about to execute a system call, dest is something | |
658 | like 0x22fc or 0x3b00. Upon completion the system call | |
659 | will return to the address in the link register. */ | |
660 | if (dest < AIX_TEXT_SEGMENT_BASE) | |
0df8b418 MS |
661 | dest = get_frame_register_unsigned (frame, |
662 | tdep->ppc_lr_regnum) & ~3; | |
4a7622d1 UW |
663 | } |
664 | else | |
665 | return -1; | |
666 | break; | |
667 | ||
668 | default: | |
669 | return -1; | |
670 | } | |
671 | return (dest < AIX_TEXT_SEGMENT_BASE) ? safety : dest; | |
672 | } | |
673 | ||
674 | /* AIX does not support PT_STEP. Simulate it. */ | |
675 | ||
676 | static int | |
677 | rs6000_software_single_step (struct frame_info *frame) | |
678 | { | |
a6d9a66e | 679 | struct gdbarch *gdbarch = get_frame_arch (frame); |
6c95b8df | 680 | struct address_space *aspace = get_frame_address_space (frame); |
e17a4113 | 681 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
4a7622d1 UW |
682 | int ii, insn; |
683 | CORE_ADDR loc; | |
684 | CORE_ADDR breaks[2]; | |
685 | int opcode; | |
686 | ||
687 | loc = get_frame_pc (frame); | |
688 | ||
e17a4113 | 689 | insn = read_memory_integer (loc, 4, byte_order); |
4a7622d1 UW |
690 | |
691 | if (ppc_deal_with_atomic_sequence (frame)) | |
692 | return 1; | |
693 | ||
694 | breaks[0] = loc + PPC_INSN_SIZE; | |
695 | opcode = insn >> 26; | |
696 | breaks[1] = branch_dest (frame, opcode, insn, loc, breaks[0]); | |
697 | ||
0df8b418 | 698 | /* Don't put two breakpoints on the same address. */ |
4a7622d1 UW |
699 | if (breaks[1] == breaks[0]) |
700 | breaks[1] = -1; | |
701 | ||
702 | for (ii = 0; ii < 2; ++ii) | |
703 | { | |
0df8b418 | 704 | /* ignore invalid breakpoint. */ |
4a7622d1 UW |
705 | if (breaks[ii] == -1) |
706 | continue; | |
6c95b8df | 707 | insert_single_step_breakpoint (gdbarch, aspace, breaks[ii]); |
4a7622d1 UW |
708 | } |
709 | ||
0df8b418 | 710 | errno = 0; /* FIXME, don't ignore errors! */ |
4a7622d1 UW |
711 | /* What errors? {read,write}_memory call error(). */ |
712 | return 1; | |
713 | } | |
714 | ||
38a69d0a JB |
715 | /* Implement the "auto_wide_charset" gdbarch method for this platform. */ |
716 | ||
717 | static const char * | |
718 | rs6000_aix_auto_wide_charset (void) | |
719 | { | |
720 | return "UTF-16"; | |
721 | } | |
722 | ||
beb4b03c JB |
723 | /* Implement an osabi sniffer for RS6000/AIX. |
724 | ||
725 | This function assumes that ABFD's flavour is XCOFF. In other words, | |
726 | it should be registered as a sniffer for bfd_target_xcoff_flavour | |
727 | objfiles only. A failed assertion will be raised if this condition | |
728 | is not met. */ | |
729 | ||
1f82754b JB |
730 | static enum gdb_osabi |
731 | rs6000_aix_osabi_sniffer (bfd *abfd) | |
732 | { | |
beb4b03c | 733 | gdb_assert (bfd_get_flavour (abfd) == bfd_target_xcoff_flavour); |
1f82754b | 734 | |
d5367fe1 JB |
735 | /* The only noticeable difference between Lynx178 XCOFF files and |
736 | AIX XCOFF files comes from the fact that there are no shared | |
737 | libraries on Lynx178. On AIX, we are betting that an executable | |
738 | linked with no shared library will never exist. */ | |
739 | if (xcoff_get_n_import_files (abfd) <= 0) | |
740 | return GDB_OSABI_UNKNOWN; | |
741 | ||
beb4b03c | 742 | return GDB_OSABI_AIX; |
1f82754b JB |
743 | } |
744 | ||
745 | static void | |
746 | rs6000_aix_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
747 | { | |
4a7622d1 UW |
748 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
749 | ||
1f82754b JB |
750 | /* RS6000/AIX does not support PT_STEP. Has to be simulated. */ |
751 | set_gdbarch_software_single_step (gdbarch, rs6000_software_single_step); | |
6f7f3f0d | 752 | |
2454a024 UW |
753 | /* Displaced stepping is currently not supported in combination with |
754 | software single-stepping. */ | |
755 | set_gdbarch_displaced_step_copy_insn (gdbarch, NULL); | |
756 | set_gdbarch_displaced_step_fixup (gdbarch, NULL); | |
757 | set_gdbarch_displaced_step_free_closure (gdbarch, NULL); | |
758 | set_gdbarch_displaced_step_location (gdbarch, NULL); | |
759 | ||
4a7622d1 UW |
760 | set_gdbarch_push_dummy_call (gdbarch, rs6000_push_dummy_call); |
761 | set_gdbarch_return_value (gdbarch, rs6000_return_value); | |
762 | set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT); | |
763 | ||
764 | /* Handle RS/6000 function pointers (which are really function | |
765 | descriptors). */ | |
766 | set_gdbarch_convert_from_func_ptr_addr | |
767 | (gdbarch, rs6000_convert_from_func_ptr_addr); | |
768 | ||
7a61a01c UW |
769 | /* Core file support. */ |
770 | set_gdbarch_regset_from_core_section | |
771 | (gdbarch, rs6000_aix_regset_from_core_section); | |
772 | ||
4a7622d1 UW |
773 | if (tdep->wordsize == 8) |
774 | tdep->lr_frame_offset = 16; | |
775 | else | |
776 | tdep->lr_frame_offset = 8; | |
777 | ||
778 | if (tdep->wordsize == 4) | |
779 | /* PowerOpen / AIX 32 bit. The saved area or red zone consists of | |
780 | 19 4 byte GPRS + 18 8 byte FPRs giving a total of 220 bytes. | |
781 | Problem is, 220 isn't frame (16 byte) aligned. Round it up to | |
782 | 224. */ | |
783 | set_gdbarch_frame_red_zone_size (gdbarch, 224); | |
784 | else | |
785 | set_gdbarch_frame_red_zone_size (gdbarch, 0); | |
38a69d0a JB |
786 | |
787 | set_gdbarch_auto_wide_charset (gdbarch, rs6000_aix_auto_wide_charset); | |
4d1eb6b4 JB |
788 | |
789 | set_solib_ops (gdbarch, &solib_aix_so_ops); | |
1f82754b JB |
790 | } |
791 | ||
63807e1d PA |
792 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
793 | extern initialize_file_ftype _initialize_rs6000_aix_tdep; | |
794 | ||
1f82754b JB |
795 | void |
796 | _initialize_rs6000_aix_tdep (void) | |
797 | { | |
798 | gdbarch_register_osabi_sniffer (bfd_arch_rs6000, | |
799 | bfd_target_xcoff_flavour, | |
800 | rs6000_aix_osabi_sniffer); | |
7a61a01c UW |
801 | gdbarch_register_osabi_sniffer (bfd_arch_powerpc, |
802 | bfd_target_xcoff_flavour, | |
803 | rs6000_aix_osabi_sniffer); | |
1f82754b JB |
804 | |
805 | gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_AIX, | |
806 | rs6000_aix_init_osabi); | |
7a61a01c UW |
807 | gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_AIX, |
808 | rs6000_aix_init_osabi); | |
1f82754b JB |
809 | } |
810 |