Commit | Line | Data |
---|---|---|
41abdfbd | 1 | /* Target-dependent code for GDB, the GNU debugger. |
211b564e | 2 | Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997 |
07aa9fdc | 3 | Free Software Foundation, Inc. |
41abdfbd JG |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
6c9638b4 | 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
41abdfbd | 20 | |
41abdfbd | 21 | #include "defs.h" |
41abdfbd JG |
22 | #include "frame.h" |
23 | #include "inferior.h" | |
24 | #include "symtab.h" | |
25 | #include "target.h" | |
030fb5cb | 26 | #include "gdbcore.h" |
65eaea27 JL |
27 | #include "symfile.h" |
28 | #include "objfiles.h" | |
2aefe6e4 JK |
29 | #include "xcoffsolib.h" |
30 | ||
d6434f39 JG |
31 | extern struct obstack frame_cache_obstack; |
32 | ||
41abdfbd | 33 | extern int errno; |
41abdfbd | 34 | |
41abdfbd JG |
35 | /* Breakpoint shadows for the single step instructions will be kept here. */ |
36 | ||
37 | static struct sstep_breaks { | |
030fb5cb JK |
38 | /* Address, or 0 if this is not in use. */ |
39 | CORE_ADDR address; | |
40 | /* Shadow contents. */ | |
41 | char data[4]; | |
41abdfbd JG |
42 | } stepBreaks[2]; |
43 | ||
05d52ace PS |
44 | /* Hook for determining the TOC address when calling functions in the |
45 | inferior under AIX. The initialization code in rs6000-nat.c sets | |
46 | this hook to point to find_toc_address. */ | |
47 | ||
48 | CORE_ADDR (*find_toc_address_hook) PARAMS ((CORE_ADDR)) = NULL; | |
ecf4059f | 49 | |
05d52ace | 50 | /* Static function prototypes */ |
ecf4059f | 51 | |
cd8a3d84 SS |
52 | static CORE_ADDR branch_dest PARAMS ((int opcode, int instr, CORE_ADDR pc, |
53 | CORE_ADDR safety)); | |
ecf4059f | 54 | |
cd8a3d84 SS |
55 | static void frame_get_cache_fsr PARAMS ((struct frame_info *fi, |
56 | struct rs6000_framedata *fdatap)); | |
57 | ||
368f1e77 FF |
58 | static void pop_dummy_frame PARAMS ((void)); |
59 | ||
cd8a3d84 | 60 | /* Calculate the destination of a branch/jump. Return -1 if not a branch. */ |
41abdfbd | 61 | |
ecf4059f | 62 | static CORE_ADDR |
41abdfbd | 63 | branch_dest (opcode, instr, pc, safety) |
ecf4059f JG |
64 | int opcode; |
65 | int instr; | |
66 | CORE_ADDR pc; | |
67 | CORE_ADDR safety; | |
41abdfbd | 68 | { |
ecf4059f | 69 | CORE_ADDR dest; |
41abdfbd JG |
70 | int immediate; |
71 | int absolute; | |
72 | int ext_op; | |
73 | ||
74 | absolute = (int) ((instr >> 1) & 1); | |
75 | ||
76 | switch (opcode) { | |
77 | case 18 : | |
ecf4059f | 78 | immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */ |
dc59e982 MM |
79 | if (absolute) |
80 | dest = immediate; | |
81 | else | |
82 | dest = pc + immediate; | |
83 | break; | |
41abdfbd JG |
84 | |
85 | case 16 : | |
dc59e982 | 86 | immediate = ((instr & ~3) << 16) >> 16; /* br conditional */ |
41abdfbd JG |
87 | if (absolute) |
88 | dest = immediate; | |
89 | else | |
90 | dest = pc + immediate; | |
91 | break; | |
92 | ||
93 | case 19 : | |
94 | ext_op = (instr>>1) & 0x3ff; | |
95 | ||
96 | if (ext_op == 16) /* br conditional register */ | |
0c6c5eeb PS |
97 | { |
98 | dest = read_register (LR_REGNUM) & ~3; | |
99 | ||
100 | /* If we are about to return from a signal handler, dest is | |
101 | something like 0x3c90. The current frame is a signal handler | |
102 | caller frame, upon completion of the sigreturn system call | |
103 | execution will return to the saved PC in the frame. */ | |
104 | if (dest < TEXT_SEGMENT_BASE) | |
105 | { | |
106 | struct frame_info *fi; | |
107 | ||
108 | fi = get_current_frame (); | |
109 | if (fi != NULL) | |
110 | dest = read_memory_integer (fi->frame + SIG_FRAME_PC_OFFSET, | |
111 | 4); | |
112 | } | |
113 | } | |
41abdfbd JG |
114 | |
115 | else if (ext_op == 528) /* br cond to count reg */ | |
9aa31e91 JK |
116 | { |
117 | dest = read_register (CTR_REGNUM) & ~3; | |
118 | ||
119 | /* If we are about to execute a system call, dest is something | |
120 | like 0x22fc or 0x3b00. Upon completion the system call | |
121 | will return to the address in the link register. */ | |
122 | if (dest < TEXT_SEGMENT_BASE) | |
123 | dest = read_register (LR_REGNUM) & ~3; | |
124 | } | |
41abdfbd JG |
125 | else return -1; |
126 | break; | |
127 | ||
128 | default: return -1; | |
129 | } | |
818de002 | 130 | return (dest < TEXT_SEGMENT_BASE) ? safety : dest; |
41abdfbd JG |
131 | } |
132 | ||
133 | ||
afcad54a AC |
134 | /* Sequence of bytes for breakpoint instruction. */ |
135 | ||
136 | #define BIG_BREAKPOINT { 0x7d, 0x82, 0x10, 0x08 } | |
137 | #define LITTLE_BREAKPOINT { 0x08, 0x10, 0x82, 0x7d } | |
138 | ||
139 | unsigned char * | |
140 | rs6000_breakpoint_from_pc (bp_addr, bp_size) | |
141 | CORE_ADDR *bp_addr; | |
142 | int *bp_size; | |
143 | { | |
07137a11 AC |
144 | static unsigned char big_breakpoint[] = BIG_BREAKPOINT; |
145 | static unsigned char little_breakpoint[] = LITTLE_BREAKPOINT; | |
afcad54a AC |
146 | *bp_size = 4; |
147 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) | |
148 | return big_breakpoint; | |
149 | else | |
150 | return little_breakpoint; | |
151 | } | |
152 | ||
41abdfbd JG |
153 | |
154 | /* AIX does not support PT_STEP. Simulate it. */ | |
155 | ||
997cc2c0 | 156 | void |
02331869 | 157 | rs6000_software_single_step (signal, insert_breakpoints_p) |
b607efe7 | 158 | enum target_signal signal; |
02331869 | 159 | int insert_breakpoints_p; |
41abdfbd JG |
160 | { |
161 | #define INSNLEN(OPCODE) 4 | |
162 | ||
5c172b4b MM |
163 | static char le_breakp[] = LITTLE_BREAKPOINT; |
164 | static char be_breakp[] = BIG_BREAKPOINT; | |
165 | char *breakp = TARGET_BYTE_ORDER == BIG_ENDIAN ? be_breakp : le_breakp; | |
030fb5cb JK |
166 | int ii, insn; |
167 | CORE_ADDR loc; | |
168 | CORE_ADDR breaks[2]; | |
169 | int opcode; | |
41abdfbd | 170 | |
02331869 AC |
171 | if (insert_breakpoints_p) { |
172 | ||
41abdfbd JG |
173 | loc = read_pc (); |
174 | ||
b112f2ae | 175 | insn = read_memory_integer (loc, 4); |
41abdfbd JG |
176 | |
177 | breaks[0] = loc + INSNLEN(insn); | |
178 | opcode = insn >> 26; | |
179 | breaks[1] = branch_dest (opcode, insn, loc, breaks[0]); | |
180 | ||
818de002 PB |
181 | /* Don't put two breakpoints on the same address. */ |
182 | if (breaks[1] == breaks[0]) | |
183 | breaks[1] = -1; | |
184 | ||
030fb5cb | 185 | stepBreaks[1].address = 0; |
41abdfbd JG |
186 | |
187 | for (ii=0; ii < 2; ++ii) { | |
188 | ||
189 | /* ignore invalid breakpoint. */ | |
190 | if ( breaks[ii] == -1) | |
191 | continue; | |
192 | ||
030fb5cb | 193 | read_memory (breaks[ii], stepBreaks[ii].data, 4); |
41abdfbd | 194 | |
030fb5cb | 195 | write_memory (breaks[ii], breakp, 4); |
41abdfbd JG |
196 | stepBreaks[ii].address = breaks[ii]; |
197 | } | |
198 | ||
997cc2c0 | 199 | } else { |
41abdfbd JG |
200 | |
201 | /* remove step breakpoints. */ | |
202 | for (ii=0; ii < 2; ++ii) | |
030fb5cb | 203 | if (stepBreaks[ii].address != 0) |
41abdfbd | 204 | write_memory |
030fb5cb | 205 | (stepBreaks[ii].address, stepBreaks[ii].data, 4); |
41abdfbd | 206 | |
41abdfbd | 207 | } |
997cc2c0 | 208 | errno = 0; /* FIXME, don't ignore errors! */ |
030fb5cb | 209 | /* What errors? {read,write}_memory call error(). */ |
41abdfbd | 210 | } |
41abdfbd JG |
211 | |
212 | ||
068c9fd6 MM |
213 | /* return pc value after skipping a function prologue and also return |
214 | information about a function frame. | |
41abdfbd | 215 | |
068c9fd6 MM |
216 | in struct rs6000_frameinfo fdata: |
217 | - frameless is TRUE, if function does not have a frame. | |
218 | - nosavedpc is TRUE, if function does not save %pc value in its frame. | |
219 | - offset is the number of bytes used in the frame to save registers. | |
220 | - saved_gpr is the number of the first saved gpr. | |
221 | - saved_fpr is the number of the first saved fpr. | |
222 | - alloca_reg is the number of the register used for alloca() handling. | |
223 | Otherwise -1. | |
224 | - gpr_offset is the offset of the saved gprs | |
225 | - fpr_offset is the offset of the saved fprs | |
226 | - lr_offset is the offset of the saved lr | |
227 | - cr_offset is the offset of the saved cr | |
228 | */ | |
229 | ||
230 | #define SIGNED_SHORT(x) \ | |
231 | ((sizeof (short) == 2) \ | |
232 | ? ((int)(short)(x)) \ | |
233 | : ((int)((((x) & 0xffff) ^ 0x8000) - 0x8000))) | |
234 | ||
235 | #define GET_SRC_REG(x) (((x) >> 21) & 0x1f) | |
236 | ||
237 | CORE_ADDR | |
238 | skip_prologue (pc, fdata) | |
239 | CORE_ADDR pc; | |
240 | struct rs6000_framedata *fdata; | |
41abdfbd | 241 | { |
068c9fd6 | 242 | CORE_ADDR orig_pc = pc; |
34df79fc | 243 | char buf[4]; |
34df79fc | 244 | unsigned long op; |
4b4c6c96 | 245 | long offset = 0; |
068c9fd6 MM |
246 | int lr_reg = 0; |
247 | int cr_reg = 0; | |
248 | int reg; | |
4b4c6c96 | 249 | int framep = 0; |
65eaea27 | 250 | int minimal_toc_loaded = 0; |
068c9fd6 MM |
251 | static struct rs6000_framedata zero_frame; |
252 | ||
253 | *fdata = zero_frame; | |
254 | fdata->saved_gpr = -1; | |
255 | fdata->saved_fpr = -1; | |
256 | fdata->alloca_reg = -1; | |
257 | fdata->frameless = 1; | |
258 | fdata->nosavedpc = 1; | |
41abdfbd | 259 | |
34df79fc | 260 | if (target_read_memory (pc, buf, 4)) |
41abdfbd | 261 | return pc; /* Can't access it -- assume no prologue. */ |
41abdfbd JG |
262 | |
263 | /* Assume that subsequent fetches can fail with low probability. */ | |
068c9fd6 MM |
264 | pc -= 4; |
265 | for (;;) | |
266 | { | |
267 | pc += 4; | |
268 | op = read_memory_integer (pc, 4); | |
41abdfbd | 269 | |
068c9fd6 MM |
270 | if ((op & 0xfc1fffff) == 0x7c0802a6) { /* mflr Rx */ |
271 | lr_reg = (op & 0x03e00000) | 0x90010000; | |
272 | continue; | |
273 | ||
274 | } else if ((op & 0xfc1fffff) == 0x7c000026) { /* mfcr Rx */ | |
275 | cr_reg = (op & 0x03e00000) | 0x90010000; | |
276 | continue; | |
277 | ||
278 | } else if ((op & 0xfc1f0000) == 0xd8010000) { /* stfd Rx,NUM(r1) */ | |
279 | reg = GET_SRC_REG (op); | |
280 | if (fdata->saved_fpr == -1 || fdata->saved_fpr > reg) { | |
281 | fdata->saved_fpr = reg; | |
4b4c6c96 | 282 | fdata->fpr_offset = SIGNED_SHORT (op) + offset; |
068c9fd6 MM |
283 | } |
284 | continue; | |
285 | ||
286 | } else if (((op & 0xfc1f0000) == 0xbc010000) || /* stm Rx, NUM(r1) */ | |
75621b2b MS |
287 | ((op & 0xfc1f0000) == 0x90010000 && /* st rx,NUM(r1), |
288 | rx >= r13 */ | |
068c9fd6 MM |
289 | (op & 0x03e00000) >= 0x01a00000)) { |
290 | ||
291 | reg = GET_SRC_REG (op); | |
292 | if (fdata->saved_gpr == -1 || fdata->saved_gpr > reg) { | |
293 | fdata->saved_gpr = reg; | |
4b4c6c96 | 294 | fdata->gpr_offset = SIGNED_SHORT (op) + offset; |
068c9fd6 MM |
295 | } |
296 | continue; | |
297 | ||
75621b2b MS |
298 | } else if ((op & 0xffff0000) == 0x3c000000) { /* addis 0,0,NUM, used |
299 | for >= 32k frames */ | |
068c9fd6 | 300 | fdata->offset = (op & 0x0000ffff) << 16; |
65eaea27 | 301 | fdata->frameless = 0; |
068c9fd6 MM |
302 | continue; |
303 | ||
75621b2b MS |
304 | } else if ((op & 0xffff0000) == 0x60000000) { /* ori 0,0,NUM, 2nd ha |
305 | lf of >= 32k frames */ | |
068c9fd6 | 306 | fdata->offset |= (op & 0x0000ffff); |
65eaea27 | 307 | fdata->frameless = 0; |
068c9fd6 MM |
308 | continue; |
309 | ||
75621b2b MS |
310 | } else if ((op & 0xffff0000) == lr_reg) { /* st Rx,NUM(r1) |
311 | where Rx == lr */ | |
4b4c6c96 | 312 | fdata->lr_offset = SIGNED_SHORT (op) + offset; |
068c9fd6 MM |
313 | fdata->nosavedpc = 0; |
314 | lr_reg = 0; | |
315 | continue; | |
316 | ||
75621b2b MS |
317 | } else if ((op & 0xffff0000) == cr_reg) { /* st Rx,NUM(r1) |
318 | where Rx == cr */ | |
4b4c6c96 | 319 | fdata->cr_offset = SIGNED_SHORT (op) + offset; |
068c9fd6 MM |
320 | cr_reg = 0; |
321 | continue; | |
322 | ||
75621b2b MS |
323 | } else if (op == 0x48000005) { /* bl .+4 used in |
324 | -mrelocatable */ | |
4b4c6c96 MM |
325 | continue; |
326 | ||
65eaea27 JL |
327 | } else if (op == 0x48000004) { /* b .+4 (xlc) */ |
328 | break; | |
329 | ||
75621b2b MS |
330 | } else if (((op & 0xffff0000) == 0x801e0000 || /* lwz 0,NUM(r30), used |
331 | in V.4 -mrelocatable */ | |
332 | op == 0x7fc0f214) && /* add r30,r0,r30, used | |
333 | in V.4 -mrelocatable */ | |
4b4c6c96 MM |
334 | lr_reg == 0x901e0000) { |
335 | continue; | |
336 | ||
75621b2b MS |
337 | } else if ((op & 0xffff0000) == 0x3fc00000 || /* addis 30,0,foo@ha, used |
338 | in V.4 -mminimal-toc */ | |
4b4c6c96 MM |
339 | (op & 0xffff0000) == 0x3bde0000) { /* addi 30,30,foo@l */ |
340 | continue; | |
341 | ||
75621b2b MS |
342 | } else if ((op & 0xfc000000) == 0x48000000) { /* bl foo, |
343 | to save fprs??? */ | |
965dde97 | 344 | |
65eaea27 | 345 | fdata->frameless = 0; |
965dde97 PS |
346 | /* Don't skip over the subroutine call if it is not within the first |
347 | three instructions of the prologue. */ | |
348 | if ((pc - orig_pc) > 8) | |
349 | break; | |
350 | ||
068c9fd6 MM |
351 | op = read_memory_integer (pc+4, 4); |
352 | ||
353 | /* At this point, make sure this is not a trampoline function | |
354 | (a function that simply calls another functions, and nothing else). | |
355 | If the next is not a nop, this branch was part of the function | |
356 | prologue. */ | |
357 | ||
358 | if (op == 0x4def7b82 || op == 0) /* crorc 15, 15, 15 */ | |
75621b2b MS |
359 | break; /* don't skip over |
360 | this branch */ | |
068c9fd6 MM |
361 | continue; |
362 | ||
4b4c6c96 | 363 | /* update stack pointer */ |
068c9fd6 | 364 | } else if ((op & 0xffff0000) == 0x94210000) { /* stu r1,NUM(r1) */ |
65eaea27 | 365 | fdata->frameless = 0; |
4b4c6c96 MM |
366 | fdata->offset = SIGNED_SHORT (op); |
367 | offset = fdata->offset; | |
368 | continue; | |
1eeba686 | 369 | |
068c9fd6 | 370 | } else if (op == 0x7c21016e) { /* stwux 1,1,0 */ |
65eaea27 | 371 | fdata->frameless = 0; |
4b4c6c96 MM |
372 | offset = fdata->offset; |
373 | continue; | |
41abdfbd | 374 | |
4b4c6c96 | 375 | /* Load up minimal toc pointer */ |
65eaea27 JL |
376 | } else if ((op >> 22) == 0x20f |
377 | && ! minimal_toc_loaded) { /* l r31,... or l r30,... */ | |
378 | minimal_toc_loaded = 1; | |
4b4c6c96 | 379 | continue; |
cdb1cc92 | 380 | |
4b4c6c96 MM |
381 | /* store parameters in stack */ |
382 | } else if ((op & 0xfc1f0000) == 0x90010000 || /* st rx,NUM(r1) */ | |
383 | (op & 0xfc1f0000) == 0xd8010000 || /* stfd Rx,NUM(r1) */ | |
384 | (op & 0xfc1f0000) == 0xfc010000) { /* frsp, fp?,NUM(r1) */ | |
385 | continue; | |
e137e850 | 386 | |
4b4c6c96 MM |
387 | /* store parameters in stack via frame pointer */ |
388 | } else if (framep && | |
58b4fad2 | 389 | ((op & 0xfc1f0000) == 0x901f0000 || /* st rx,NUM(r1) */ |
4b4c6c96 | 390 | (op & 0xfc1f0000) == 0xd81f0000 || /* stfd Rx,NUM(r1) */ |
58b4fad2 | 391 | (op & 0xfc1f0000) == 0xfc1f0000)) { /* frsp, fp?,NUM(r1) */ |
4b4c6c96 | 392 | continue; |
e137e850 | 393 | |
4b4c6c96 MM |
394 | /* Set up frame pointer */ |
395 | } else if (op == 0x603f0000 /* oril r31, r1, 0x0 */ | |
396 | || op == 0x7c3f0b78) { /* mr r31, r1 */ | |
65eaea27 | 397 | fdata->frameless = 0; |
4b4c6c96 | 398 | framep = 1; |
965dde97 | 399 | fdata->alloca_reg = 31; |
4b4c6c96 | 400 | continue; |
41abdfbd | 401 | |
65eaea27 JL |
402 | /* Another way to set up the frame pointer. */ |
403 | } else if ((op & 0xfc1fffff) == 0x38010000) { /* addi rX, r1, 0x0 */ | |
404 | fdata->frameless = 0; | |
405 | framep = 1; | |
406 | fdata->alloca_reg = (op & ~0x38010000) >> 21; | |
407 | continue; | |
408 | ||
4b4c6c96 MM |
409 | } else { |
410 | break; | |
411 | } | |
41abdfbd | 412 | } |
068c9fd6 | 413 | |
507e4004 PB |
414 | #if 0 |
415 | /* I have problems with skipping over __main() that I need to address | |
416 | * sometime. Previously, I used to use misc_function_vector which | |
417 | * didn't work as well as I wanted to be. -MGO */ | |
418 | ||
419 | /* If the first thing after skipping a prolog is a branch to a function, | |
420 | this might be a call to an initializer in main(), introduced by gcc2. | |
421 | We'd like to skip over it as well. Fortunately, xlc does some extra | |
422 | work before calling a function right after a prologue, thus we can | |
423 | single out such gcc2 behaviour. */ | |
424 | ||
425 | ||
426 | if ((op & 0xfc000001) == 0x48000001) { /* bl foo, an initializer function? */ | |
427 | op = read_memory_integer (pc+4, 4); | |
428 | ||
429 | if (op == 0x4def7b82) { /* cror 0xf, 0xf, 0xf (nop) */ | |
430 | ||
431 | /* check and see if we are in main. If so, skip over this initializer | |
432 | function as well. */ | |
433 | ||
434 | tmp = find_pc_misc_function (pc); | |
2e4964ad | 435 | if (tmp >= 0 && STREQ (misc_function_vector [tmp].name, "main")) |
507e4004 PB |
436 | return pc + 8; |
437 | } | |
438 | } | |
439 | #endif /* 0 */ | |
440 | ||
4b4c6c96 | 441 | fdata->offset = - fdata->offset; |
41abdfbd JG |
442 | return pc; |
443 | } | |
444 | ||
818de002 | 445 | |
41abdfbd JG |
446 | /************************************************************************* |
447 | Support for creating pushind a dummy frame into the stack, and popping | |
448 | frames, etc. | |
449 | *************************************************************************/ | |
450 | ||
818de002 PB |
451 | /* The total size of dummy frame is 436, which is; |
452 | ||
453 | 32 gpr's - 128 bytes | |
454 | 32 fpr's - 256 " | |
455 | 7 the rest - 28 " | |
456 | and 24 extra bytes for the callee's link area. The last 24 bytes | |
457 | for the link area might not be necessary, since it will be taken | |
458 | care of by push_arguments(). */ | |
459 | ||
460 | #define DUMMY_FRAME_SIZE 436 | |
461 | ||
41abdfbd JG |
462 | #define DUMMY_FRAME_ADDR_SIZE 10 |
463 | ||
464 | /* Make sure you initialize these in somewhere, in case gdb gives up what it | |
818de002 | 465 | was debugging and starts debugging something else. FIXMEibm */ |
41abdfbd JG |
466 | |
467 | static int dummy_frame_count = 0; | |
468 | static int dummy_frame_size = 0; | |
469 | static CORE_ADDR *dummy_frame_addr = 0; | |
470 | ||
471 | extern int stop_stack_dummy; | |
472 | ||
473 | /* push a dummy frame into stack, save all register. Currently we are saving | |
474 | only gpr's and fpr's, which is not good enough! FIXMEmgo */ | |
475 | ||
ecf4059f | 476 | void |
41abdfbd JG |
477 | push_dummy_frame () |
478 | { | |
359a097f JK |
479 | /* stack pointer. */ |
480 | CORE_ADDR sp; | |
b112f2ae JK |
481 | /* Same thing, target byte order. */ |
482 | char sp_targ[4]; | |
359a097f JK |
483 | |
484 | /* link register. */ | |
485 | CORE_ADDR pc; | |
486 | /* Same thing, target byte order. */ | |
487 | char pc_targ[4]; | |
488 | ||
3a4f9786 MT |
489 | /* Needed to figure out where to save the dummy link area. |
490 | FIXME: There should be an easier way to do this, no? tiemann 9/9/95. */ | |
491 | struct rs6000_framedata fdata; | |
492 | ||
41abdfbd JG |
493 | int ii; |
494 | ||
5f1c39ef | 495 | target_fetch_registers (-1); |
6c6afbb9 | 496 | |
41abdfbd JG |
497 | if (dummy_frame_count >= dummy_frame_size) { |
498 | dummy_frame_size += DUMMY_FRAME_ADDR_SIZE; | |
499 | if (dummy_frame_addr) | |
500 | dummy_frame_addr = (CORE_ADDR*) xrealloc | |
501 | (dummy_frame_addr, sizeof(CORE_ADDR) * (dummy_frame_size)); | |
502 | else | |
503 | dummy_frame_addr = (CORE_ADDR*) | |
504 | xmalloc (sizeof(CORE_ADDR) * (dummy_frame_size)); | |
505 | } | |
506 | ||
507 | sp = read_register(SP_REGNUM); | |
359a097f | 508 | pc = read_register(PC_REGNUM); |
5816555b | 509 | store_address (pc_targ, 4, pc); |
41abdfbd | 510 | |
75621b2b | 511 | skip_prologue (get_pc_function_start (pc) + FUNCTION_START_OFFSET, &fdata); |
3a4f9786 | 512 | |
41abdfbd JG |
513 | dummy_frame_addr [dummy_frame_count++] = sp; |
514 | ||
515 | /* Be careful! If the stack pointer is not decremented first, then kernel | |
6c6afbb9 | 516 | thinks he is free to use the space underneath it. And kernel actually |
41abdfbd JG |
517 | uses that area for IPC purposes when executing ptrace(2) calls. So |
518 | before writing register values into the new frame, decrement and update | |
519 | %sp first in order to secure your frame. */ | |
520 | ||
3a4f9786 MT |
521 | /* FIXME: We don't check if the stack really has this much space. |
522 | This is a problem on the ppc simulator (which only grants one page | |
523 | (4096 bytes) by default. */ | |
524 | ||
818de002 | 525 | write_register (SP_REGNUM, sp-DUMMY_FRAME_SIZE); |
41abdfbd | 526 | |
41abdfbd JG |
527 | /* gdb relies on the state of current_frame. We'd better update it, |
528 | otherwise things like do_registers_info() wouldn't work properly! */ | |
529 | ||
530 | flush_cached_frames (); | |
41abdfbd JG |
531 | |
532 | /* save program counter in link register's space. */ | |
4f8710e6 PS |
533 | write_memory (sp + (fdata.lr_offset ? fdata.lr_offset : DEFAULT_LR_SAVE), |
534 | pc_targ, 4); | |
41abdfbd | 535 | |
6c6afbb9 | 536 | /* save all floating point and general purpose registers here. */ |
41abdfbd JG |
537 | |
538 | /* fpr's, f0..f31 */ | |
539 | for (ii = 0; ii < 32; ++ii) | |
540 | write_memory (sp-8-(ii*8), ®isters[REGISTER_BYTE (31-ii+FP0_REGNUM)], 8); | |
541 | ||
542 | /* gpr's r0..r31 */ | |
543 | for (ii=1; ii <=32; ++ii) | |
544 | write_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); | |
545 | ||
818de002 PB |
546 | /* so far, 32*2 + 32 words = 384 bytes have been written. |
547 | 7 extra registers in our register set: pc, ps, cnd, lr, cnt, xer, mq */ | |
548 | ||
549 | for (ii=1; ii <= (LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) { | |
550 | write_memory (sp-384-(ii*4), | |
75621b2b | 551 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); |
818de002 PB |
552 | } |
553 | ||
554 | /* Save sp or so called back chain right here. */ | |
b112f2ae JK |
555 | store_address (sp_targ, 4, sp); |
556 | write_memory (sp-DUMMY_FRAME_SIZE, sp_targ, 4); | |
818de002 | 557 | sp -= DUMMY_FRAME_SIZE; |
41abdfbd JG |
558 | |
559 | /* And finally, this is the back chain. */ | |
359a097f | 560 | write_memory (sp+8, pc_targ, 4); |
41abdfbd JG |
561 | } |
562 | ||
563 | ||
564 | /* Pop a dummy frame. | |
565 | ||
566 | In rs6000 when we push a dummy frame, we save all of the registers. This | |
567 | is usually done before user calls a function explicitly. | |
568 | ||
818de002 PB |
569 | After a dummy frame is pushed, some instructions are copied into stack, |
570 | and stack pointer is decremented even more. Since we don't have a frame | |
571 | pointer to get back to the parent frame of the dummy, we start having | |
572 | trouble poping it. Therefore, we keep a dummy frame stack, keeping | |
573 | addresses of dummy frames as such. When poping happens and when we | |
574 | detect that was a dummy frame, we pop it back to its parent by using | |
575 | dummy frame stack (`dummy_frame_addr' array). | |
ecf4059f JG |
576 | |
577 | FIXME: This whole concept is broken. You should be able to detect | |
578 | a dummy stack frame *on the user's stack itself*. When you do, | |
579 | then you know the format of that stack frame -- including its | |
580 | saved SP register! There should *not* be a separate stack in the | |
d6434f39 | 581 | GDB process that keeps track of these dummy frames! -- gnu@cygnus.com Aug92 |
41abdfbd JG |
582 | */ |
583 | ||
368f1e77 | 584 | static void |
41abdfbd JG |
585 | pop_dummy_frame () |
586 | { | |
587 | CORE_ADDR sp, pc; | |
588 | int ii; | |
589 | sp = dummy_frame_addr [--dummy_frame_count]; | |
590 | ||
591 | /* restore all fpr's. */ | |
592 | for (ii = 1; ii <= 32; ++ii) | |
593 | read_memory (sp-(ii*8), ®isters[REGISTER_BYTE (32-ii+FP0_REGNUM)], 8); | |
594 | ||
595 | /* restore all gpr's */ | |
596 | for (ii=1; ii <= 32; ++ii) { | |
597 | read_memory (sp-256-(ii*4), ®isters[REGISTER_BYTE (32-ii)], 4); | |
598 | } | |
599 | ||
818de002 PB |
600 | /* restore the rest of the registers. */ |
601 | for (ii=1; ii <=(LAST_SP_REGNUM-FIRST_SP_REGNUM+1); ++ii) | |
602 | read_memory (sp-384-(ii*4), | |
603 | ®isters[REGISTER_BYTE (FPLAST_REGNUM + ii)], 4); | |
604 | ||
605 | read_memory (sp-(DUMMY_FRAME_SIZE-8), | |
3a4f9786 | 606 | ®isters [REGISTER_BYTE(PC_REGNUM)], 4); |
41abdfbd JG |
607 | |
608 | /* when a dummy frame was being pushed, we had to decrement %sp first, in | |
609 | order to secure astack space. Thus, saved %sp (or %r1) value, is not the | |
610 | one we should restore. Change it with the one we need. */ | |
611 | ||
75621b2b | 612 | memcpy (®isters [REGISTER_BYTE(FP_REGNUM)], (char *) &sp, sizeof (int)); |
41abdfbd JG |
613 | |
614 | /* Now we can restore all registers. */ | |
615 | ||
5f1c39ef | 616 | target_store_registers (-1); |
41abdfbd JG |
617 | pc = read_pc (); |
618 | flush_cached_frames (); | |
41abdfbd JG |
619 | } |
620 | ||
621 | ||
622 | /* pop the innermost frame, go back to the caller. */ | |
623 | ||
ecf4059f | 624 | void |
41abdfbd JG |
625 | pop_frame () |
626 | { | |
359a097f | 627 | CORE_ADDR pc, lr, sp, prev_sp; /* %pc, %lr, %sp */ |
63641491 | 628 | struct rs6000_framedata fdata; |
669caa9c | 629 | struct frame_info *frame = get_current_frame (); |
41abdfbd | 630 | int addr, ii; |
41abdfbd JG |
631 | |
632 | pc = read_pc (); | |
669caa9c | 633 | sp = FRAME_FP (frame); |
41abdfbd | 634 | |
0ec1e44d MA |
635 | if (stop_stack_dummy) |
636 | { | |
637 | #ifdef USE_GENERIC_DUMMY_FRAMES | |
638 | generic_pop_dummy_frame (); | |
639 | flush_cached_frames (); | |
640 | return; | |
641 | #else | |
642 | if (dummy_frame_count) | |
643 | pop_dummy_frame (); | |
644 | return; | |
645 | #endif | |
646 | } | |
41abdfbd | 647 | |
07aa9fdc PS |
648 | /* Make sure that all registers are valid. */ |
649 | read_register_bytes (0, NULL, REGISTER_BYTES); | |
650 | ||
41abdfbd JG |
651 | /* figure out previous %pc value. If the function is frameless, it is |
652 | still in the link register, otherwise walk the frames and retrieve the | |
653 | saved %pc value in the previous frame. */ | |
654 | ||
34a1a3bf | 655 | addr = get_pc_function_start (frame->pc) + FUNCTION_START_OFFSET; |
068c9fd6 | 656 | (void) skip_prologue (addr, &fdata); |
41abdfbd | 657 | |
6c6afbb9 | 658 | if (fdata.frameless) |
07aa9fdc PS |
659 | prev_sp = sp; |
660 | else | |
661 | prev_sp = read_memory_integer (sp, 4); | |
068c9fd6 | 662 | if (fdata.lr_offset == 0) |
41abdfbd JG |
663 | lr = read_register (LR_REGNUM); |
664 | else | |
068c9fd6 | 665 | lr = read_memory_integer (prev_sp + fdata.lr_offset, 4); |
41abdfbd JG |
666 | |
667 | /* reset %pc value. */ | |
668 | write_register (PC_REGNUM, lr); | |
669 | ||
670 | /* reset register values if any was saved earlier. */ | |
6c6afbb9 | 671 | addr = prev_sp - fdata.offset; |
41abdfbd | 672 | |
6c6afbb9 | 673 | if (fdata.saved_gpr != -1) |
669caa9c | 674 | for (ii = fdata.saved_gpr; ii <= 31; ++ii) { |
41abdfbd | 675 | read_memory (addr, ®isters [REGISTER_BYTE (ii)], 4); |
cdb1cc92 | 676 | addr += 4; |
41abdfbd JG |
677 | } |
678 | ||
6c6afbb9 | 679 | if (fdata.saved_fpr != -1) |
669caa9c | 680 | for (ii = fdata.saved_fpr; ii <= 31; ++ii) { |
41abdfbd JG |
681 | read_memory (addr, ®isters [REGISTER_BYTE (ii+FP0_REGNUM)], 8); |
682 | addr += 8; | |
683 | } | |
684 | ||
685 | write_register (SP_REGNUM, prev_sp); | |
5f1c39ef | 686 | target_store_registers (-1); |
41abdfbd | 687 | flush_cached_frames (); |
41abdfbd JG |
688 | } |
689 | ||
41abdfbd JG |
690 | /* fixup the call sequence of a dummy function, with the real function address. |
691 | its argumets will be passed by gdb. */ | |
692 | ||
ecf4059f | 693 | void |
2f163bc3 | 694 | rs6000_fix_call_dummy (dummyname, pc, fun, nargs, args, type, gcc_p) |
cd8a3d84 SS |
695 | char *dummyname; |
696 | CORE_ADDR pc; | |
697 | CORE_ADDR fun; | |
2f163bc3 SS |
698 | int nargs; |
699 | value_ptr *args; | |
700 | struct type *type; | |
701 | int gcc_p; | |
41abdfbd JG |
702 | { |
703 | #define TOC_ADDR_OFFSET 20 | |
704 | #define TARGET_ADDR_OFFSET 28 | |
705 | ||
706 | int ii; | |
ecf4059f | 707 | CORE_ADDR target_addr; |
41abdfbd | 708 | |
05d52ace PS |
709 | if (find_toc_address_hook != NULL) |
710 | { | |
711 | CORE_ADDR tocvalue; | |
41abdfbd | 712 | |
05d52ace PS |
713 | tocvalue = (*find_toc_address_hook) (fun); |
714 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET); | |
715 | ii = (ii & 0xffff0000) | (tocvalue >> 16); | |
716 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET) = ii; | |
41abdfbd | 717 | |
05d52ace PS |
718 | ii = *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4); |
719 | ii = (ii & 0xffff0000) | (tocvalue & 0x0000ffff); | |
720 | *(int*)((char*)dummyname + TOC_ADDR_OFFSET+4) = ii; | |
721 | } | |
41abdfbd | 722 | |
05d52ace | 723 | target_addr = fun; |
41abdfbd JG |
724 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET); |
725 | ii = (ii & 0xffff0000) | (target_addr >> 16); | |
726 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET) = ii; | |
727 | ||
728 | ii = *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4); | |
729 | ii = (ii & 0xffff0000) | (target_addr & 0x0000ffff); | |
730 | *(int*)((char*)dummyname + TARGET_ADDR_OFFSET+4) = ii; | |
731 | } | |
732 | ||
cd8a3d84 SS |
733 | /* Pass the arguments in either registers, or in the stack. In RS6000, |
734 | the first eight words of the argument list (that might be less than | |
735 | eight parameters if some parameters occupy more than one word) are | |
736 | passed in r3..r11 registers. float and double parameters are | |
737 | passed in fpr's, in addition to that. Rest of the parameters if any | |
738 | are passed in user stack. There might be cases in which half of the | |
739 | parameter is copied into registers, the other half is pushed into | |
41abdfbd JG |
740 | stack. |
741 | ||
742 | If the function is returning a structure, then the return address is passed | |
94b4f756 | 743 | in r3, then the first 7 words of the parameters can be passed in registers, |
41abdfbd JG |
744 | starting from r4. */ |
745 | ||
746 | CORE_ADDR | |
747 | push_arguments (nargs, args, sp, struct_return, struct_addr) | |
cd8a3d84 SS |
748 | int nargs; |
749 | value_ptr *args; | |
750 | CORE_ADDR sp; | |
751 | int struct_return; | |
752 | CORE_ADDR struct_addr; | |
41abdfbd | 753 | { |
368f1e77 FF |
754 | int ii; |
755 | int len = 0; | |
41abdfbd JG |
756 | int argno; /* current argument number */ |
757 | int argbytes; /* current argument byte */ | |
758 | char tmp_buffer [50]; | |
41abdfbd | 759 | int f_argno = 0; /* current floating point argno */ |
0ec1e44d | 760 | |
368f1e77 | 761 | value_ptr arg = 0; |
940d5967 | 762 | struct type *type; |
41abdfbd | 763 | |
368f1e77 | 764 | CORE_ADDR saved_sp; |
41abdfbd | 765 | |
0ec1e44d | 766 | #ifndef USE_GENERIC_DUMMY_FRAMES |
41abdfbd | 767 | if ( dummy_frame_count <= 0) |
199b2450 | 768 | printf_unfiltered ("FATAL ERROR -push_arguments()! frame not found!!\n"); |
0ec1e44d | 769 | #endif /* GENERIC_DUMMY_FRAMES */ |
41abdfbd JG |
770 | |
771 | /* The first eight words of ther arguments are passed in registers. Copy | |
772 | them appropriately. | |
773 | ||
774 | If the function is returning a `struct', then the first word (which | |
775 | will be passed in r3) is used for struct return address. In that | |
776 | case we should advance one word and start from r4 register to copy | |
777 | parameters. */ | |
778 | ||
779 | ii = struct_return ? 1 : 0; | |
780 | ||
0ec1e44d MA |
781 | /* |
782 | effectively indirect call... gcc does... | |
783 | ||
784 | return_val example( float, int); | |
785 | ||
786 | eabi: | |
787 | float in fp0, int in r3 | |
788 | offset of stack on overflow 8/16 | |
789 | for varargs, must go by type. | |
790 | power open: | |
791 | float in r3&r4, int in r5 | |
792 | offset of stack on overflow different | |
793 | both: | |
794 | return in r3 or f0. If no float, must study how gcc emulates floats; | |
795 | pay attention to arg promotion. | |
796 | User may have to cast\args to handle promotion correctly | |
797 | since gdb won't know if prototype supplied or not. | |
798 | */ | |
799 | ||
41abdfbd JG |
800 | for (argno=0, argbytes=0; argno < nargs && ii<8; ++ii) { |
801 | ||
5222ca60 | 802 | arg = args[argno]; |
59c84318 | 803 | type = check_typedef (VALUE_TYPE (arg)); |
940d5967 | 804 | len = TYPE_LENGTH (type); |
41abdfbd | 805 | |
940d5967 | 806 | if (TYPE_CODE (type) == TYPE_CODE_FLT) { |
41abdfbd JG |
807 | |
808 | /* floating point arguments are passed in fpr's, as well as gpr's. | |
809 | There are 13 fpr's reserved for passing parameters. At this point | |
810 | there is no way we would run out of them. */ | |
811 | ||
812 | if (len > 8) | |
199b2450 | 813 | printf_unfiltered ( |
41abdfbd JG |
814 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
815 | ||
75621b2b MS |
816 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], |
817 | VALUE_CONTENTS (arg), | |
818 | len); | |
41abdfbd JG |
819 | ++f_argno; |
820 | } | |
821 | ||
822 | if (len > 4) { | |
823 | ||
824 | /* Argument takes more than one register. */ | |
825 | while (argbytes < len) { | |
75621b2b | 826 | memset (®isters[REGISTER_BYTE(ii+3)], 0, sizeof(int)); |
ade40d31 | 827 | memcpy (®isters[REGISTER_BYTE(ii+3)], |
75621b2b MS |
828 | ((char*)VALUE_CONTENTS (arg))+argbytes, |
829 | (len - argbytes) > 4 ? 4 : len - argbytes); | |
41abdfbd JG |
830 | ++ii, argbytes += 4; |
831 | ||
832 | if (ii >= 8) | |
833 | goto ran_out_of_registers_for_arguments; | |
834 | } | |
835 | argbytes = 0; | |
836 | --ii; | |
837 | } | |
838 | else { /* Argument can fit in one register. No problem. */ | |
75621b2b | 839 | memset (®isters[REGISTER_BYTE(ii+3)], 0, sizeof(int)); |
ade40d31 | 840 | memcpy (®isters[REGISTER_BYTE(ii+3)], VALUE_CONTENTS (arg), len); |
41abdfbd JG |
841 | } |
842 | ++argno; | |
843 | } | |
844 | ||
845 | ran_out_of_registers_for_arguments: | |
846 | ||
0ec1e44d MA |
847 | #ifdef USE_GENERIC_DUMMY_FRAMES |
848 | saved_sp = read_sp (); | |
849 | #else | |
41abdfbd JG |
850 | /* location for 8 parameters are always reserved. */ |
851 | sp -= 4 * 8; | |
852 | ||
853 | /* another six words for back chain, TOC register, link register, etc. */ | |
854 | sp -= 24; | |
0ec1e44d | 855 | #endif /* GENERIC_DUMMY_FRAMES */ |
41abdfbd JG |
856 | /* if there are more arguments, allocate space for them in |
857 | the stack, then push them starting from the ninth one. */ | |
858 | ||
859 | if ((argno < nargs) || argbytes) { | |
860 | int space = 0, jj; | |
41abdfbd JG |
861 | |
862 | if (argbytes) { | |
863 | space += ((len - argbytes + 3) & -4); | |
864 | jj = argno + 1; | |
865 | } | |
866 | else | |
867 | jj = argno; | |
868 | ||
869 | for (; jj < nargs; ++jj) { | |
940d5967 | 870 | value_ptr val = args[jj]; |
41abdfbd JG |
871 | space += ((TYPE_LENGTH (VALUE_TYPE (val))) + 3) & -4; |
872 | } | |
873 | ||
874 | /* add location required for the rest of the parameters */ | |
875 | space = (space + 7) & -8; | |
876 | sp -= space; | |
877 | ||
878 | /* This is another instance we need to be concerned about securing our | |
879 | stack space. If we write anything underneath %sp (r1), we might conflict | |
880 | with the kernel who thinks he is free to use this area. So, update %sp | |
881 | first before doing anything else. */ | |
882 | ||
883 | write_register (SP_REGNUM, sp); | |
884 | ||
41abdfbd JG |
885 | /* if the last argument copied into the registers didn't fit there |
886 | completely, push the rest of it into stack. */ | |
887 | ||
888 | if (argbytes) { | |
75621b2b MS |
889 | write_memory (sp+24+(ii*4), |
890 | ((char*)VALUE_CONTENTS (arg))+argbytes, | |
891 | len - argbytes); | |
41abdfbd JG |
892 | ++argno; |
893 | ii += ((len - argbytes + 3) & -4) / 4; | |
894 | } | |
895 | ||
896 | /* push the rest of the arguments into stack. */ | |
897 | for (; argno < nargs; ++argno) { | |
898 | ||
5222ca60 | 899 | arg = args[argno]; |
940d5967 PB |
900 | type = check_typedef (VALUE_TYPE (arg)); |
901 | len = TYPE_LENGTH (type); | |
41abdfbd JG |
902 | |
903 | ||
904 | /* float types should be passed in fpr's, as well as in the stack. */ | |
940d5967 | 905 | if (TYPE_CODE (type) == TYPE_CODE_FLT && f_argno < 13) { |
41abdfbd JG |
906 | |
907 | if (len > 8) | |
199b2450 | 908 | printf_unfiltered ( |
41abdfbd JG |
909 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); |
910 | ||
75621b2b MS |
911 | memcpy (®isters[REGISTER_BYTE(FP0_REGNUM + 1 + f_argno)], |
912 | VALUE_CONTENTS (arg), | |
913 | len); | |
41abdfbd JG |
914 | ++f_argno; |
915 | } | |
916 | ||
359a097f | 917 | write_memory (sp+24+(ii*4), (char *) VALUE_CONTENTS (arg), len); |
41abdfbd JG |
918 | ii += ((len + 3) & -4) / 4; |
919 | } | |
920 | } | |
6c6afbb9 | 921 | else |
41abdfbd JG |
922 | /* Secure stack areas first, before doing anything else. */ |
923 | write_register (SP_REGNUM, sp); | |
924 | ||
0ec1e44d MA |
925 | #ifndef USE_GENERIC_DUMMY_FRAMES |
926 | /* we want to copy 24 bytes of target's frame to dummy's frame, | |
927 | then set back chain to point to new frame. */ | |
928 | ||
41abdfbd JG |
929 | saved_sp = dummy_frame_addr [dummy_frame_count - 1]; |
930 | read_memory (saved_sp, tmp_buffer, 24); | |
931 | write_memory (sp, tmp_buffer, 24); | |
0ec1e44d | 932 | #endif /* GENERIC_DUMMY_FRAMES */ |
41abdfbd | 933 | |
b112f2ae JK |
934 | /* set back chain properly */ |
935 | store_address (tmp_buffer, 4, saved_sp); | |
936 | write_memory (sp, tmp_buffer, 4); | |
41abdfbd | 937 | |
5f1c39ef | 938 | target_store_registers (-1); |
41abdfbd JG |
939 | return sp; |
940 | } | |
0ec1e44d MA |
941 | #ifdef ELF_OBJECT_FORMAT |
942 | ||
943 | /* Function: ppc_push_return_address (pc, sp) | |
944 | Set up the return address for the inferior function call. */ | |
945 | ||
946 | CORE_ADDR | |
947 | ppc_push_return_address (pc, sp) | |
948 | CORE_ADDR pc; | |
949 | CORE_ADDR sp; | |
950 | { | |
951 | write_register (LR_REGNUM, CALL_DUMMY_ADDRESS ()); | |
952 | return sp; | |
953 | } | |
954 | ||
955 | #endif | |
41abdfbd JG |
956 | |
957 | /* a given return value in `regbuf' with a type `valtype', extract and copy its | |
958 | value into `valbuf' */ | |
959 | ||
ecf4059f | 960 | void |
41abdfbd | 961 | extract_return_value (valtype, regbuf, valbuf) |
cd8a3d84 SS |
962 | struct type *valtype; |
963 | char regbuf[REGISTER_BYTES]; | |
964 | char *valbuf; | |
41abdfbd | 965 | { |
07781ac0 | 966 | int offset = 0; |
41abdfbd JG |
967 | |
968 | if (TYPE_CODE (valtype) == TYPE_CODE_FLT) { | |
969 | ||
970 | double dd; float ff; | |
971 | /* floats and doubles are returned in fpr1. fpr's have a size of 8 bytes. | |
972 | We need to truncate the return value into float size (4 byte) if | |
973 | necessary. */ | |
974 | ||
975 | if (TYPE_LENGTH (valtype) > 4) /* this is a double */ | |
75621b2b MS |
976 | memcpy (valbuf, |
977 | ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], | |
978 | TYPE_LENGTH (valtype)); | |
41abdfbd | 979 | else { /* float */ |
ade40d31 | 980 | memcpy (&dd, ®buf[REGISTER_BYTE (FP0_REGNUM + 1)], 8); |
41abdfbd | 981 | ff = (float)dd; |
ade40d31 | 982 | memcpy (valbuf, &ff, sizeof(float)); |
41abdfbd JG |
983 | } |
984 | } | |
07781ac0 | 985 | else { |
41abdfbd | 986 | /* return value is copied starting from r3. */ |
07781ac0 PS |
987 | if (TARGET_BYTE_ORDER == BIG_ENDIAN |
988 | && TYPE_LENGTH (valtype) < REGISTER_RAW_SIZE (3)) | |
989 | offset = REGISTER_RAW_SIZE (3) - TYPE_LENGTH (valtype); | |
990 | ||
75621b2b MS |
991 | memcpy (valbuf, |
992 | regbuf + REGISTER_BYTE (3) + offset, | |
07781ac0 PS |
993 | TYPE_LENGTH (valtype)); |
994 | } | |
41abdfbd JG |
995 | } |
996 | ||
997 | ||
ecf4059f JG |
998 | /* keep structure return address in this variable. |
999 | FIXME: This is a horrid kludge which should not be allowed to continue | |
1000 | living. This only allows a single nested call to a structure-returning | |
1001 | function. Come on, guys! -- gnu@cygnus.com, Aug 92 */ | |
41abdfbd JG |
1002 | |
1003 | CORE_ADDR rs6000_struct_return_address; | |
1004 | ||
1005 | ||
c2e4669f JG |
1006 | /* Indirect function calls use a piece of trampoline code to do context |
1007 | switching, i.e. to set the new TOC table. Skip such code if we are on | |
1008 | its first instruction (as when we have single-stepped to here). | |
07aa9fdc PS |
1009 | Also skip shared library trampoline code (which is different from |
1010 | indirect function call trampolines). | |
c2e4669f JG |
1011 | Result is desired PC to step until, or NULL if we are not in |
1012 | trampoline code. */ | |
41abdfbd | 1013 | |
ecf4059f | 1014 | CORE_ADDR |
41abdfbd | 1015 | skip_trampoline_code (pc) |
cd8a3d84 | 1016 | CORE_ADDR pc; |
41abdfbd JG |
1017 | { |
1018 | register unsigned int ii, op; | |
07aa9fdc | 1019 | CORE_ADDR solib_target_pc; |
41abdfbd JG |
1020 | |
1021 | static unsigned trampoline_code[] = { | |
1022 | 0x800b0000, /* l r0,0x0(r11) */ | |
1023 | 0x90410014, /* st r2,0x14(r1) */ | |
1024 | 0x7c0903a6, /* mtctr r0 */ | |
1025 | 0x804b0004, /* l r2,0x4(r11) */ | |
1026 | 0x816b0008, /* l r11,0x8(r11) */ | |
1027 | 0x4e800420, /* bctr */ | |
1028 | 0x4e800020, /* br */ | |
1029 | 0 | |
1030 | }; | |
1031 | ||
07aa9fdc PS |
1032 | /* If pc is in a shared library trampoline, return its target. */ |
1033 | solib_target_pc = find_solib_trampoline_target (pc); | |
1034 | if (solib_target_pc) | |
1035 | return solib_target_pc; | |
1036 | ||
41abdfbd JG |
1037 | for (ii=0; trampoline_code[ii]; ++ii) { |
1038 | op = read_memory_integer (pc + (ii*4), 4); | |
1039 | if (op != trampoline_code [ii]) | |
359a097f | 1040 | return 0; |
41abdfbd JG |
1041 | } |
1042 | ii = read_register (11); /* r11 holds destination addr */ | |
1043 | pc = read_memory_integer (ii, 4); /* (r11) value */ | |
1044 | return pc; | |
1045 | } | |
1046 | ||
068c9fd6 | 1047 | /* Determines whether the function FI has a frame on the stack or not. */ |
cd8a3d84 | 1048 | |
ecf4059f | 1049 | int |
068c9fd6 MM |
1050 | frameless_function_invocation (fi) |
1051 | struct frame_info *fi; | |
ecf4059f JG |
1052 | { |
1053 | CORE_ADDR func_start; | |
63641491 | 1054 | struct rs6000_framedata fdata; |
ecf4059f | 1055 | |
4cc56716 PS |
1056 | /* Don't even think about framelessness except on the innermost frame |
1057 | or if the function was interrupted by a signal. */ | |
1058 | if (fi->next != NULL && !fi->next->signal_handler_caller) | |
b0e932ad JK |
1059 | return 0; |
1060 | ||
4cc56716 | 1061 | func_start = get_pc_function_start (fi->pc); |
ecf4059f JG |
1062 | |
1063 | /* If we failed to find the start of the function, it is a mistake | |
1064 | to inspect the instructions. */ | |
1065 | ||
1066 | if (!func_start) | |
4cc56716 PS |
1067 | { |
1068 | /* A frame with a zero PC is usually created by dereferencing a NULL | |
1069 | function pointer, normally causing an immediate core dump of the | |
1070 | inferior. Mark function as frameless, as the inferior has no chance | |
1071 | of setting up a stack frame. */ | |
1072 | if (fi->pc == 0) | |
1073 | return 1; | |
1074 | else | |
1075 | return 0; | |
1076 | } | |
ecf4059f | 1077 | |
4cc56716 | 1078 | func_start += FUNCTION_START_OFFSET; |
068c9fd6 MM |
1079 | (void) skip_prologue (func_start, &fdata); |
1080 | return fdata.frameless; | |
ecf4059f JG |
1081 | } |
1082 | ||
068c9fd6 | 1083 | /* Return the PC saved in a frame */ |
cd8a3d84 | 1084 | |
068c9fd6 MM |
1085 | unsigned long |
1086 | frame_saved_pc (fi) | |
1087 | struct frame_info *fi; | |
1088 | { | |
1089 | CORE_ADDR func_start; | |
1090 | struct rs6000_framedata fdata; | |
068c9fd6 | 1091 | |
965dde97 PS |
1092 | if (fi->signal_handler_caller) |
1093 | return read_memory_integer (fi->frame + SIG_FRAME_PC_OFFSET, 4); | |
1094 | ||
0ec1e44d MA |
1095 | #ifdef USE_GENERIC_DUMMY_FRAMES |
1096 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
1097 | return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM); | |
1098 | #endif /* GENERIC_DUMMY_FRAMES */ | |
1099 | ||
068c9fd6 MM |
1100 | func_start = get_pc_function_start (fi->pc) + FUNCTION_START_OFFSET; |
1101 | ||
1102 | /* If we failed to find the start of the function, it is a mistake | |
1103 | to inspect the instructions. */ | |
1104 | if (!func_start) | |
1105 | return 0; | |
1106 | ||
1107 | (void) skip_prologue (func_start, &fdata); | |
068c9fd6 | 1108 | |
4b4c6c96 | 1109 | if (fdata.lr_offset == 0 && fi->next != NULL) |
4cc56716 PS |
1110 | { |
1111 | if (fi->next->signal_handler_caller) | |
1112 | return read_memory_integer (fi->next->frame + SIG_FRAME_LR_OFFSET, 4); | |
1113 | else | |
1114 | return read_memory_integer (rs6000_frame_chain (fi) + DEFAULT_LR_SAVE, | |
1115 | 4); | |
1116 | } | |
4b4c6c96 MM |
1117 | |
1118 | if (fdata.lr_offset == 0) | |
1119 | return read_register (LR_REGNUM); | |
1120 | ||
068c9fd6 MM |
1121 | return read_memory_integer (rs6000_frame_chain (fi) + fdata.lr_offset, 4); |
1122 | } | |
ecf4059f JG |
1123 | |
1124 | /* If saved registers of frame FI are not known yet, read and cache them. | |
63641491 | 1125 | &FDATAP contains rs6000_framedata; TDATAP can be NULL, |
ecf4059f JG |
1126 | in which case the framedata are read. */ |
1127 | ||
1128 | static void | |
1129 | frame_get_cache_fsr (fi, fdatap) | |
1130 | struct frame_info *fi; | |
63641491 | 1131 | struct rs6000_framedata *fdatap; |
ecf4059f JG |
1132 | { |
1133 | int ii; | |
1134 | CORE_ADDR frame_addr; | |
63641491 | 1135 | struct rs6000_framedata work_fdata; |
ecf4059f JG |
1136 | |
1137 | if (fi->cache_fsr) | |
1138 | return; | |
1139 | ||
1140 | if (fdatap == NULL) { | |
1141 | fdatap = &work_fdata; | |
068c9fd6 | 1142 | (void) skip_prologue (get_pc_function_start (fi->pc), fdatap); |
ecf4059f JG |
1143 | } |
1144 | ||
1145 | fi->cache_fsr = (struct frame_saved_regs *) | |
1146 | obstack_alloc (&frame_cache_obstack, sizeof (struct frame_saved_regs)); | |
4ed97c9a | 1147 | memset (fi->cache_fsr, '\0', sizeof (struct frame_saved_regs)); |
ecf4059f JG |
1148 | |
1149 | if (fi->prev && fi->prev->frame) | |
1150 | frame_addr = fi->prev->frame; | |
1151 | else | |
1152 | frame_addr = read_memory_integer (fi->frame, 4); | |
1153 | ||
1154 | /* if != -1, fdatap->saved_fpr is the smallest number of saved_fpr. | |
965dde97 | 1155 | All fpr's from saved_fpr to fp31 are saved. */ |
ecf4059f JG |
1156 | |
1157 | if (fdatap->saved_fpr >= 0) { | |
965dde97 PS |
1158 | int fpr_offset = frame_addr + fdatap->fpr_offset; |
1159 | for (ii = fdatap->saved_fpr; ii < 32; ii++) { | |
1160 | fi->cache_fsr->regs [FP0_REGNUM + ii] = fpr_offset; | |
1161 | fpr_offset += 8; | |
1162 | } | |
ecf4059f JG |
1163 | } |
1164 | ||
1165 | /* if != -1, fdatap->saved_gpr is the smallest number of saved_gpr. | |
965dde97 | 1166 | All gpr's from saved_gpr to gpr31 are saved. */ |
ecf4059f | 1167 | |
965dde97 PS |
1168 | if (fdatap->saved_gpr >= 0) { |
1169 | int gpr_offset = frame_addr + fdatap->gpr_offset; | |
1170 | for (ii = fdatap->saved_gpr; ii < 32; ii++) { | |
1171 | fi->cache_fsr->regs [ii] = gpr_offset; | |
1172 | gpr_offset += 4; | |
1173 | } | |
1174 | } | |
1175 | ||
1176 | /* If != 0, fdatap->cr_offset is the offset from the frame that holds | |
1177 | the CR. */ | |
1178 | if (fdatap->cr_offset != 0) | |
1179 | fi->cache_fsr->regs [CR_REGNUM] = frame_addr + fdatap->cr_offset; | |
1180 | ||
1181 | /* If != 0, fdatap->lr_offset is the offset from the frame that holds | |
1182 | the LR. */ | |
1183 | if (fdatap->lr_offset != 0) | |
1184 | fi->cache_fsr->regs [LR_REGNUM] = frame_addr + fdatap->lr_offset; | |
ecf4059f JG |
1185 | } |
1186 | ||
1187 | /* Return the address of a frame. This is the inital %sp value when the frame | |
1188 | was first allocated. For functions calling alloca(), it might be saved in | |
1189 | an alloca register. */ | |
1190 | ||
1191 | CORE_ADDR | |
1192 | frame_initial_stack_address (fi) | |
1193 | struct frame_info *fi; | |
1194 | { | |
1195 | CORE_ADDR tmpaddr; | |
63641491 | 1196 | struct rs6000_framedata fdata; |
ecf4059f JG |
1197 | struct frame_info *callee_fi; |
1198 | ||
1199 | /* if the initial stack pointer (frame address) of this frame is known, | |
1200 | just return it. */ | |
1201 | ||
1202 | if (fi->initial_sp) | |
1203 | return fi->initial_sp; | |
1204 | ||
1205 | /* find out if this function is using an alloca register.. */ | |
1206 | ||
068c9fd6 | 1207 | (void) skip_prologue (get_pc_function_start (fi->pc), &fdata); |
ecf4059f JG |
1208 | |
1209 | /* if saved registers of this frame are not known yet, read and cache them. */ | |
1210 | ||
1211 | if (!fi->cache_fsr) | |
1212 | frame_get_cache_fsr (fi, &fdata); | |
1213 | ||
1214 | /* If no alloca register used, then fi->frame is the value of the %sp for | |
1215 | this frame, and it is good enough. */ | |
1216 | ||
1217 | if (fdata.alloca_reg < 0) { | |
1218 | fi->initial_sp = fi->frame; | |
1219 | return fi->initial_sp; | |
1220 | } | |
1221 | ||
1222 | /* This function has an alloca register. If this is the top-most frame | |
1223 | (with the lowest address), the value in alloca register is good. */ | |
1224 | ||
1225 | if (!fi->next) | |
1226 | return fi->initial_sp = read_register (fdata.alloca_reg); | |
1227 | ||
1228 | /* Otherwise, this is a caller frame. Callee has usually already saved | |
1229 | registers, but there are exceptions (such as when the callee | |
1230 | has no parameters). Find the address in which caller's alloca | |
1231 | register is saved. */ | |
1232 | ||
1233 | for (callee_fi = fi->next; callee_fi; callee_fi = callee_fi->next) { | |
1234 | ||
1235 | if (!callee_fi->cache_fsr) | |
cdb1cc92 | 1236 | frame_get_cache_fsr (callee_fi, NULL); |
ecf4059f JG |
1237 | |
1238 | /* this is the address in which alloca register is saved. */ | |
1239 | ||
1240 | tmpaddr = callee_fi->cache_fsr->regs [fdata.alloca_reg]; | |
1241 | if (tmpaddr) { | |
1242 | fi->initial_sp = read_memory_integer (tmpaddr, 4); | |
1243 | return fi->initial_sp; | |
1244 | } | |
1245 | ||
1246 | /* Go look into deeper levels of the frame chain to see if any one of | |
1247 | the callees has saved alloca register. */ | |
1248 | } | |
1249 | ||
1250 | /* If alloca register was not saved, by the callee (or any of its callees) | |
1251 | then the value in the register is still good. */ | |
1252 | ||
1253 | return fi->initial_sp = read_register (fdata.alloca_reg); | |
1254 | } | |
1255 | ||
669caa9c | 1256 | CORE_ADDR |
f3649227 JK |
1257 | rs6000_frame_chain (thisframe) |
1258 | struct frame_info *thisframe; | |
1259 | { | |
669caa9c | 1260 | CORE_ADDR fp; |
0ec1e44d MA |
1261 | |
1262 | #ifdef USE_GENERIC_DUMMY_FRAMES | |
1263 | if (PC_IN_CALL_DUMMY (thisframe->pc, thisframe->frame, thisframe->frame)) | |
1264 | return thisframe->frame; /* dummy frame same as caller's frame */ | |
1265 | #endif /* GENERIC_DUMMY_FRAMES */ | |
1266 | ||
1267 | if (inside_entry_file (thisframe->pc) || | |
1268 | thisframe->pc == entry_point_address ()) | |
f3649227 | 1269 | return 0; |
0ec1e44d | 1270 | |
cee86be3 | 1271 | if (thisframe->signal_handler_caller) |
9ed8604f | 1272 | fp = read_memory_integer (thisframe->frame + SIG_FRAME_FP_OFFSET, 4); |
4cc56716 PS |
1273 | else if (thisframe->next != NULL |
1274 | && thisframe->next->signal_handler_caller | |
1275 | && frameless_function_invocation (thisframe)) | |
1276 | /* A frameless function interrupted by a signal did not change the | |
1277 | frame pointer. */ | |
1278 | fp = FRAME_FP (thisframe); | |
cee86be3 JK |
1279 | else |
1280 | fp = read_memory_integer ((thisframe)->frame, 4); | |
1281 | ||
0ec1e44d MA |
1282 | #ifdef USE_GENERIC_DUMMY_FRAMES |
1283 | { | |
1284 | CORE_ADDR fpp, lr; | |
1285 | ||
1286 | lr = read_register (LR_REGNUM); | |
1287 | if (lr == entry_point_address ()) | |
1288 | if (fp != 0 && (fpp = read_memory_integer (fp, 4)) != 0) | |
1289 | if (PC_IN_CALL_DUMMY (lr, fpp, fpp)) | |
1290 | return fpp; | |
1291 | } | |
1292 | #endif /* GENERIC_DUMMY_FRAMES */ | |
f3649227 JK |
1293 | return fp; |
1294 | } | |
ecf4059f | 1295 | \f |
65eaea27 JL |
1296 | /* Return nonzero if ADDR (a function pointer) is in the data space and |
1297 | is therefore a special function pointer. */ | |
1298 | ||
1299 | int | |
1300 | is_magic_function_pointer (addr) | |
1301 | CORE_ADDR addr; | |
1302 | { | |
1303 | struct obj_section *s; | |
1304 | ||
1305 | s = find_pc_section (addr); | |
1306 | if (s && s->the_bfd_section->flags & SEC_CODE) | |
1307 | return 0; | |
1308 | else | |
1309 | return 1; | |
1310 | } | |
1311 | ||
5c172b4b MM |
1312 | #ifdef GDB_TARGET_POWERPC |
1313 | int | |
1314 | gdb_print_insn_powerpc (memaddr, info) | |
1315 | bfd_vma memaddr; | |
1316 | disassemble_info *info; | |
1317 | { | |
1318 | if (TARGET_BYTE_ORDER == BIG_ENDIAN) | |
1319 | return print_insn_big_powerpc (memaddr, info); | |
1320 | else | |
1321 | return print_insn_little_powerpc (memaddr, info); | |
1322 | } | |
1323 | #endif | |
1324 | ||
0ec1e44d MA |
1325 | /* Function: get_saved_register |
1326 | Just call the generic_get_saved_register function. */ | |
1327 | ||
70423641 | 1328 | #ifdef USE_GENERIC_DUMMY_FRAMES |
0ec1e44d MA |
1329 | void |
1330 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) | |
1331 | char *raw_buffer; | |
1332 | int *optimized; | |
1333 | CORE_ADDR *addrp; | |
1334 | struct frame_info *frame; | |
1335 | int regnum; | |
1336 | enum lval_type *lval; | |
1337 | { | |
1338 | generic_get_saved_register (raw_buffer, optimized, addrp, | |
1339 | frame, regnum, lval); | |
1340 | } | |
70423641 | 1341 | #endif |
0ec1e44d MA |
1342 | |
1343 | ||
18b46e7c SS |
1344 | void |
1345 | _initialize_rs6000_tdep () | |
1346 | { | |
1347 | /* FIXME, this should not be decided via ifdef. */ | |
1348 | #ifdef GDB_TARGET_POWERPC | |
5c172b4b | 1349 | tm_print_insn = gdb_print_insn_powerpc; |
18b46e7c SS |
1350 | #else |
1351 | tm_print_insn = print_insn_rs6000; | |
1352 | #endif | |
1353 | } |