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ea3c0839 JG |
1 | /* Target-machine dependent code for Motorola 88000 series, for GDB. |
2 | Copyright (C) 1988, 1990, 1991 Free Software Foundation, Inc. | |
8aa13b87 JK |
3 | |
4 | This file is part of GDB. | |
5 | ||
99a7de40 | 6 | This program is free software; you can redistribute it and/or modify |
8aa13b87 | 7 | it under the terms of the GNU General Public License as published by |
99a7de40 JG |
8 | the Free Software Foundation; either version 2 of the License, or |
9 | (at your option) any later version. | |
8aa13b87 | 10 | |
99a7de40 | 11 | This program is distributed in the hope that it will be useful, |
8aa13b87 JK |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
99a7de40 JG |
17 | along with this program; if not, write to the Free Software |
18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
8aa13b87 | 19 | |
8aa13b87 | 20 | #include "defs.h" |
8aa13b87 JK |
21 | #include "frame.h" |
22 | #include "inferior.h" | |
23 | #include "value.h" | |
8aa13b87 | 24 | #include "gdbcore.h" |
8aa13b87 JK |
25 | |
26 | #include "symtab.h" | |
27 | #include "setjmp.h" | |
28 | #include "value.h" | |
817ac7f8 | 29 | #include "ieee-float.h" /* for ext_format & friends */ |
8aa13b87 | 30 | |
2a770cac JG |
31 | /* Size of an instruction */ |
32 | #define BYTES_PER_88K_INSN 4 | |
33 | ||
ea3c0839 | 34 | void frame_find_saved_regs (); |
8aa13b87 | 35 | |
817ac7f8 RP |
36 | /* is this target an m88110? Otherwise assume m88100. This has |
37 | relevance for the ways in which we screw with instruction pointers. */ | |
38 | int target_is_m88110 = 0; | |
39 | ||
40 | /* FIXME: this is really just a guess based on m88110 being big | |
41 | endian. */ | |
42 | const struct ext_format ext_format_m88110 = { | |
43 | /* tot sbyte smask expbyte manbyte */ | |
44 | 10, 0, 0x80, 0,1, 4,8 /* m88110 */ | |
45 | }; | |
ea3c0839 JG |
46 | |
47 | /* Given a GDB frame, determine the address of the calling function's frame. | |
48 | This will be used to create a new GDB frame struct, and then | |
49 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. | |
50 | ||
51 | For us, the frame address is its stack pointer value, so we look up | |
52 | the function prologue to determine the caller's sp value, and return it. */ | |
53 | ||
54 | FRAME_ADDR | |
55 | frame_chain (thisframe) | |
56 | FRAME thisframe; | |
8aa13b87 | 57 | { |
8aa13b87 | 58 | |
ea3c0839 JG |
59 | frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0); |
60 | /* NOTE: this depends on frame_find_saved_regs returning the VALUE, not | |
61 | the ADDRESS, of SP_REGNUM. It also depends on the cache of | |
62 | frame_find_saved_regs results. */ | |
63 | if (thisframe->fsr->regs[SP_REGNUM]) | |
64 | return thisframe->fsr->regs[SP_REGNUM]; | |
65 | else | |
66 | return thisframe->frame; /* Leaf fn -- next frame up has same SP. */ | |
67 | } | |
8aa13b87 | 68 | |
ea3c0839 JG |
69 | int |
70 | frameless_function_invocation (frame) | |
71 | FRAME frame; | |
8aa13b87 | 72 | { |
ea3c0839 JG |
73 | |
74 | frame_find_saved_regs (frame, (struct frame_saved_regs *) 0); | |
75 | /* NOTE: this depends on frame_find_saved_regs returning the VALUE, not | |
76 | the ADDRESS, of SP_REGNUM. It also depends on the cache of | |
77 | frame_find_saved_regs results. */ | |
78 | if (frame->fsr->regs[SP_REGNUM]) | |
79 | return 0; /* Frameful -- return addr saved somewhere */ | |
8aa13b87 | 80 | else |
ea3c0839 | 81 | return 1; /* Frameless -- no saved return address */ |
8aa13b87 JK |
82 | } |
83 | ||
ea3c0839 JG |
84 | void |
85 | init_extra_frame_info (fromleaf, fi) | |
86 | int fromleaf; | |
87 | struct frame_info *fi; | |
88 | { | |
89 | fi->fsr = 0; /* Not yet allocated */ | |
90 | fi->args_pointer = 0; /* Unknown */ | |
91 | fi->locals_pointer = 0; /* Unknown */ | |
92 | } | |
ea3c0839 JG |
93 | \f |
94 | /* Examine an m88k function prologue, recording the addresses at which | |
95 | registers are saved explicitly by the prologue code, and returning | |
96 | the address of the first instruction after the prologue (but not | |
97 | after the instruction at address LIMIT, as explained below). | |
98 | ||
99 | LIMIT places an upper bound on addresses of the instructions to be | |
100 | examined. If the prologue code scan reaches LIMIT, the scan is | |
101 | aborted and LIMIT is returned. This is used, when examining the | |
102 | prologue for the current frame, to keep examine_prologue () from | |
103 | claiming that a given register has been saved when in fact the | |
104 | instruction that saves it has not yet been executed. LIMIT is used | |
105 | at other times to stop the scan when we hit code after the true | |
106 | function prologue (e.g. for the first source line) which might | |
107 | otherwise be mistaken for function prologue. | |
108 | ||
109 | The format of the function prologue matched by this routine is | |
110 | derived from examination of the source to gcc 1.95, particularly | |
111 | the routine output_prologue () in config/out-m88k.c. | |
112 | ||
113 | subu r31,r31,n # stack pointer update | |
114 | ||
115 | (st rn,r31,offset)? # save incoming regs | |
116 | (st.d rn,r31,offset)? | |
117 | ||
118 | (addu r30,r31,n)? # frame pointer update | |
119 | ||
120 | (pic sequence)? # PIC code prologue | |
430923f3 JG |
121 | |
122 | (or rn,rm,0)? # Move parameters to other regs | |
ea3c0839 JG |
123 | */ |
124 | ||
125 | /* Macros for extracting fields from instructions. */ | |
126 | ||
127 | #define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos)) | |
128 | #define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width)) | |
129 | ||
130 | /* Prologue code that handles position-independent-code setup. */ | |
131 | ||
132 | struct pic_prologue_code { | |
133 | unsigned long insn, mask; | |
134 | }; | |
135 | ||
136 | static struct pic_prologue_code pic_prologue_code [] = { | |
137 | /* FIXME -- until this is translated to hex, we won't match it... */ | |
817ac7f8 | 138 | { 0xffffffff, 0 }, |
ea3c0839 JG |
139 | /* or r10,r1,0 (if not saved) */ |
140 | /* bsr.n LabN */ | |
141 | /* or.u r25,r0,const */ | |
142 | /*LabN: or r25,r25,const2 */ | |
143 | /* addu r25,r25,1 */ | |
144 | /* or r1,r10,0 (if not saved) */ | |
145 | }; | |
146 | ||
147 | /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or | |
148 | is not the address of a valid instruction, the address of the next | |
149 | instruction beyond ADDR otherwise. *PWORD1 receives the first word | |
150 | of the instruction. PWORD2 is ignored -- a remnant of the original | |
151 | i960 version. */ | |
152 | ||
637603f9 | 153 | #define NEXT_PROLOGUE_INSN(addr, lim, pword1) \ |
ea3c0839 JG |
154 | (((addr) < (lim)) ? next_insn (addr, pword1) : 0) |
155 | ||
156 | /* Read the m88k instruction at 'memaddr' and return the address of | |
157 | the next instruction after that, or 0 if 'memaddr' is not the | |
158 | address of a valid instruction. The instruction | |
159 | is stored at 'pword1'. */ | |
8aa13b87 | 160 | |
ea3c0839 JG |
161 | CORE_ADDR |
162 | next_insn (memaddr, pword1) | |
163 | unsigned long *pword1; | |
164 | CORE_ADDR memaddr; | |
8aa13b87 | 165 | { |
2a770cac JG |
166 | *pword1 = read_memory_integer (memaddr, BYTES_PER_88K_INSN); |
167 | return memaddr + BYTES_PER_88K_INSN; | |
8aa13b87 JK |
168 | } |
169 | ||
ea3c0839 | 170 | /* Read a register from frames called by us (or from the hardware regs). */ |
8aa13b87 | 171 | |
637603f9 | 172 | static int |
ea3c0839 JG |
173 | read_next_frame_reg(fi, regno) |
174 | FRAME fi; | |
175 | int regno; | |
8aa13b87 | 176 | { |
ea3c0839 JG |
177 | for (; fi; fi = fi->next) { |
178 | if (regno == SP_REGNUM) return fi->frame; | |
179 | else if (fi->fsr->regs[regno]) | |
180 | return read_memory_integer(fi->fsr->regs[regno], 4); | |
181 | } | |
182 | return read_register(regno); | |
8aa13b87 | 183 | } |
8aa13b87 | 184 | |
ea3c0839 JG |
185 | /* Examine the prologue of a function. `ip' points to the first instruction. |
186 | `limit' is the limit of the prologue (e.g. the addr of the first | |
187 | linenumber, or perhaps the program counter if we're stepping through). | |
188 | `frame_sp' is the stack pointer value in use in this frame. | |
189 | `fsr' is a pointer to a frame_saved_regs structure into which we put | |
190 | info about the registers saved by this frame. | |
191 | `fi' is a struct frame_info pointer; we fill in various fields in it | |
192 | to reflect the offsets of the arg pointer and the locals pointer. */ | |
193 | ||
194 | static CORE_ADDR | |
195 | examine_prologue (ip, limit, frame_sp, fsr, fi) | |
196 | register CORE_ADDR ip; | |
197 | register CORE_ADDR limit; | |
198 | FRAME_ADDR frame_sp; | |
199 | struct frame_saved_regs *fsr; | |
200 | struct frame_info *fi; | |
201 | { | |
202 | register CORE_ADDR next_ip; | |
203 | register int src; | |
204 | register struct pic_prologue_code *pcode; | |
637603f9 | 205 | unsigned int insn; |
ea3c0839 JG |
206 | int size, offset; |
207 | char must_adjust[32]; /* If set, must adjust offsets in fsr */ | |
208 | int sp_offset = -1; /* -1 means not set (valid must be mult of 8) */ | |
209 | int fp_offset = -1; /* -1 means not set */ | |
210 | CORE_ADDR frame_fp; | |
211 | ||
4ed97c9a | 212 | memset (must_adjust, '\0', sizeof (must_adjust)); |
637603f9 | 213 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
ea3c0839 | 214 | |
653d6c56 JG |
215 | /* Accept move of incoming registers to other registers, using |
216 | "or rd,rs,0" or "or.u rd,rs,0" or "or rd,r0,rs" or "or rd,rs,r0". | |
217 | We don't have to worry about walking into the first lines of code, | |
218 | since the first line number will stop us (assuming we have symbols). | |
219 | What we have actually seen is "or r10,r0,r12". */ | |
220 | ||
221 | #define OR_MOVE_INSN 0x58000000 /* or/or.u with immed of 0 */ | |
222 | #define OR_MOVE_MASK 0xF800FFFF | |
223 | #define OR_REG_MOVE1_INSN 0xF4005800 /* or rd,r0,rs */ | |
224 | #define OR_REG_MOVE1_MASK 0xFC1FFFE0 | |
225 | #define OR_REG_MOVE2_INSN 0xF4005800 /* or rd,rs,r0 */ | |
226 | #define OR_REG_MOVE2_MASK 0xFC00FFFF | |
227 | while (next_ip && | |
637603f9 RP |
228 | ((insn & OR_MOVE_MASK) == OR_MOVE_INSN || |
229 | (insn & OR_REG_MOVE1_MASK) == OR_REG_MOVE1_INSN || | |
230 | (insn & OR_REG_MOVE2_MASK) == OR_REG_MOVE2_INSN | |
653d6c56 JG |
231 | ) |
232 | ) | |
233 | { | |
234 | /* We don't care what moves to where. The result of the moves | |
235 | has already been reflected in what the compiler tells us is the | |
236 | location of these parameters. */ | |
237 | ip = next_ip; | |
637603f9 | 238 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
653d6c56 JG |
239 | } |
240 | ||
ea3c0839 JG |
241 | /* Accept an optional "subu sp,sp,n" to set up the stack pointer. */ |
242 | ||
243 | #define SUBU_SP_INSN 0x67ff0000 | |
244 | #define SUBU_SP_MASK 0xffff0007 /* Note offset must be mult. of 8 */ | |
245 | #define SUBU_OFFSET(x) ((unsigned)(x & 0xFFFF)) | |
246 | if (next_ip && | |
637603f9 | 247 | ((insn & SUBU_SP_MASK) == SUBU_SP_INSN)) /* subu r31, r31, N */ |
ea3c0839 | 248 | { |
637603f9 | 249 | sp_offset = -SUBU_OFFSET (insn); |
ea3c0839 | 250 | ip = next_ip; |
637603f9 | 251 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
ea3c0839 JG |
252 | } |
253 | ||
254 | /* The function must start with a stack-pointer adjustment, or | |
255 | we don't know WHAT'S going on... */ | |
256 | if (sp_offset == -1) | |
257 | return ip; | |
258 | ||
259 | /* Accept zero or more instances of "st rx,sp,n" or "st.d rx,sp,n". | |
260 | This may cause us to mistake the copying of a register | |
261 | parameter to the frame for the saving of a callee-saved | |
262 | register, but that can't be helped, since with the | |
263 | "-fcall-saved" flag, any register can be made callee-saved. | |
264 | This probably doesn't matter, since the ``saved'' caller's values of | |
265 | non-callee-saved registers are not relevant anyway. */ | |
266 | ||
267 | #define STD_STACK_INSN 0x201f0000 | |
268 | #define STD_STACK_MASK 0xfc1f0000 | |
269 | #define ST_STACK_INSN 0x241f0000 | |
270 | #define ST_STACK_MASK 0xfc1f0000 | |
271 | #define ST_OFFSET(x) ((unsigned)((x) & 0xFFFF)) | |
272 | #define ST_SRC(x) EXTRACT_FIELD ((x), 21, 5) | |
273 | ||
274 | while (next_ip) | |
275 | { | |
637603f9 | 276 | if ((insn & ST_STACK_MASK) == ST_STACK_INSN) |
ea3c0839 | 277 | size = 1; |
637603f9 | 278 | else if ((insn & STD_STACK_MASK) == STD_STACK_INSN) |
ea3c0839 JG |
279 | size = 2; |
280 | else | |
281 | break; | |
282 | ||
637603f9 RP |
283 | src = ST_SRC (insn); |
284 | offset = ST_OFFSET (insn); | |
ea3c0839 JG |
285 | while (size--) |
286 | { | |
287 | must_adjust[src] = 1; | |
288 | fsr->regs[src++] = offset; /* Will be adjusted later */ | |
289 | offset += 4; | |
290 | } | |
291 | ip = next_ip; | |
637603f9 | 292 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
ea3c0839 JG |
293 | } |
294 | ||
295 | /* Accept an optional "addu r30,r31,n" to set up the frame pointer. */ | |
296 | ||
297 | #define ADDU_FP_INSN 0x63df0000 | |
298 | #define ADDU_FP_MASK 0xffff0000 | |
299 | #define ADDU_OFFSET(x) ((unsigned)(x & 0xFFFF)) | |
300 | if (next_ip && | |
637603f9 | 301 | ((insn & ADDU_FP_MASK) == ADDU_FP_INSN)) /* addu r30, r31, N */ |
ea3c0839 | 302 | { |
637603f9 | 303 | fp_offset = ADDU_OFFSET (insn); |
ea3c0839 | 304 | ip = next_ip; |
637603f9 | 305 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
ea3c0839 JG |
306 | } |
307 | ||
308 | /* Accept the PIC prologue code if present. */ | |
309 | ||
310 | pcode = pic_prologue_code; | |
311 | size = sizeof (pic_prologue_code) / sizeof (*pic_prologue_code); | |
312 | /* If return addr is saved, we don't use first or last insn of PICstuff. */ | |
313 | if (fsr->regs[SRP_REGNUM]) { | |
314 | pcode++; | |
315 | size-=2; | |
316 | } | |
317 | ||
637603f9 | 318 | while (size-- && next_ip && (pcode->insn == (pcode->mask & insn))) |
ea3c0839 JG |
319 | { |
320 | pcode++; | |
321 | ip = next_ip; | |
637603f9 | 322 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
ea3c0839 JG |
323 | } |
324 | ||
430923f3 JG |
325 | /* Accept moves of parameter registers to other registers, using |
326 | "or rd,rs,0" or "or.u rd,rs,0" or "or rd,r0,rs" or "or rd,rs,r0". | |
327 | We don't have to worry about walking into the first lines of code, | |
328 | since the first line number will stop us (assuming we have symbols). | |
329 | What gcc actually seems to produce is "or rd,r0,rs". */ | |
330 | ||
331 | #define OR_MOVE_INSN 0x58000000 /* or/or.u with immed of 0 */ | |
332 | #define OR_MOVE_MASK 0xF800FFFF | |
333 | #define OR_REG_MOVE1_INSN 0xF4005800 /* or rd,r0,rs */ | |
334 | #define OR_REG_MOVE1_MASK 0xFC1FFFE0 | |
335 | #define OR_REG_MOVE2_INSN 0xF4005800 /* or rd,rs,r0 */ | |
336 | #define OR_REG_MOVE2_MASK 0xFC00FFFF | |
337 | while (next_ip && | |
637603f9 RP |
338 | ((insn & OR_MOVE_MASK) == OR_MOVE_INSN || |
339 | (insn & OR_REG_MOVE1_MASK) == OR_REG_MOVE1_INSN || | |
340 | (insn & OR_REG_MOVE2_MASK) == OR_REG_MOVE2_INSN | |
430923f3 JG |
341 | ) |
342 | ) | |
343 | { | |
344 | /* We don't care what moves to where. The result of the moves | |
345 | has already been reflected in what the compiler tells us is the | |
346 | location of these parameters. */ | |
347 | ip = next_ip; | |
637603f9 | 348 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn); |
430923f3 JG |
349 | } |
350 | ||
ea3c0839 JG |
351 | /* We're done with the prologue. If we don't care about the stack |
352 | frame itself, just return. (Note that fsr->regs has been trashed, | |
353 | but the one caller who calls with fi==0 passes a dummy there.) */ | |
354 | ||
355 | if (fi == 0) | |
356 | return ip; | |
357 | ||
637603f9 RP |
358 | /* |
359 | OK, now we have: | |
360 | ||
361 | sp_offset original (before any alloca calls) displacement of SP | |
362 | (will be negative). | |
363 | ||
364 | fp_offset displacement from original SP to the FP for this frame | |
365 | or -1. | |
366 | ||
367 | fsr->regs[0..31] displacement from original SP to the stack | |
368 | location where reg[0..31] is stored. | |
369 | ||
370 | must_adjust[0..31] set if corresponding offset was set. | |
ea3c0839 | 371 | |
637603f9 RP |
372 | If alloca has been called between the function prologue and the current |
373 | IP, then the current SP (frame_sp) will not be the original SP as set by | |
374 | the function prologue. If the current SP is not the original SP, then the | |
375 | compiler will have allocated an FP for this frame, fp_offset will be set, | |
376 | and we can use it to calculate the original SP. | |
ea3c0839 | 377 | |
637603f9 RP |
378 | Then, we figure out where the arguments and locals are, and relocate the |
379 | offsets in fsr->regs to absolute addresses. */ | |
ea3c0839 JG |
380 | |
381 | if (fp_offset != -1) { | |
382 | /* We have a frame pointer, so get it, and base our calc's on it. */ | |
637603f9 | 383 | frame_fp = (CORE_ADDR) read_next_frame_reg (fi->next, ACTUAL_FP_REGNUM); |
ea3c0839 JG |
384 | frame_sp = frame_fp - fp_offset; |
385 | } else { | |
386 | /* We have no frame pointer, therefore frame_sp is still the same value | |
387 | as set by prologue. But where is the frame itself? */ | |
388 | if (must_adjust[SRP_REGNUM]) { | |
389 | /* Function header saved SRP (r1), the return address. Frame starts | |
390 | 4 bytes down from where it was saved. */ | |
391 | frame_fp = frame_sp + fsr->regs[SRP_REGNUM] - 4; | |
392 | fi->locals_pointer = frame_fp; | |
393 | } else { | |
394 | /* Function header didn't save SRP (r1), so we are in a leaf fn or | |
395 | are otherwise confused. */ | |
396 | frame_fp = -1; | |
397 | } | |
398 | } | |
399 | ||
400 | /* The locals are relative to the FP (whether it exists as an allocated | |
401 | register, or just as an assumed offset from the SP) */ | |
402 | fi->locals_pointer = frame_fp; | |
403 | ||
404 | /* The arguments are just above the SP as it was before we adjusted it | |
405 | on entry. */ | |
406 | fi->args_pointer = frame_sp - sp_offset; | |
407 | ||
408 | /* Now that we know the SP value used by the prologue, we know where | |
409 | it saved all the registers. */ | |
410 | for (src = 0; src < 32; src++) | |
411 | if (must_adjust[src]) | |
412 | fsr->regs[src] += frame_sp; | |
413 | ||
414 | /* The saved value of the SP is always known. */ | |
415 | /* (we hope...) */ | |
416 | if (fsr->regs[SP_REGNUM] != 0 | |
417 | && fsr->regs[SP_REGNUM] != frame_sp - sp_offset) | |
418 | fprintf(stderr, "Bad saved SP value %x != %x, offset %x!\n", | |
419 | fsr->regs[SP_REGNUM], | |
420 | frame_sp - sp_offset, sp_offset); | |
421 | ||
422 | fsr->regs[SP_REGNUM] = frame_sp - sp_offset; | |
8aa13b87 | 423 | |
ea3c0839 JG |
424 | return (ip); |
425 | } | |
8aa13b87 | 426 | |
ea3c0839 JG |
427 | /* Given an ip value corresponding to the start of a function, |
428 | return the ip of the first instruction after the function | |
429 | prologue. */ | |
8aa13b87 JK |
430 | |
431 | CORE_ADDR | |
ea3c0839 JG |
432 | skip_prologue (ip) |
433 | CORE_ADDR (ip); | |
8aa13b87 | 434 | { |
ea3c0839 JG |
435 | struct frame_saved_regs saved_regs_dummy; |
436 | struct symtab_and_line sal; | |
437 | CORE_ADDR limit; | |
8aa13b87 | 438 | |
ea3c0839 JG |
439 | sal = find_pc_line (ip, 0); |
440 | limit = (sal.end) ? sal.end : 0xffffffff; | |
441 | ||
442 | return (examine_prologue (ip, limit, (FRAME_ADDR) 0, &saved_regs_dummy, | |
443 | (struct frame_info *)0 )); | |
444 | } | |
445 | ||
446 | /* Put here the code to store, into a struct frame_saved_regs, | |
447 | the addresses of the saved registers of frame described by FRAME_INFO. | |
448 | This includes special registers such as pc and fp saved in special | |
449 | ways in the stack frame. sp is even more special: | |
450 | the address we return for it IS the sp for the next frame. | |
451 | ||
452 | We cache the result of doing this in the frame_cache_obstack, since | |
453 | it is fairly expensive. */ | |
454 | ||
455 | void | |
456 | frame_find_saved_regs (fi, fsr) | |
457 | struct frame_info *fi; | |
458 | struct frame_saved_regs *fsr; | |
459 | { | |
ea3c0839 JG |
460 | register struct frame_saved_regs *cache_fsr; |
461 | extern struct obstack frame_cache_obstack; | |
462 | CORE_ADDR ip; | |
463 | struct symtab_and_line sal; | |
464 | CORE_ADDR limit; | |
465 | ||
466 | if (!fi->fsr) | |
8aa13b87 | 467 | { |
ea3c0839 JG |
468 | cache_fsr = (struct frame_saved_regs *) |
469 | obstack_alloc (&frame_cache_obstack, | |
470 | sizeof (struct frame_saved_regs)); | |
4ed97c9a | 471 | memset (cache_fsr, '\0', sizeof (struct frame_saved_regs)); |
ea3c0839 JG |
472 | fi->fsr = cache_fsr; |
473 | ||
474 | /* Find the start and end of the function prologue. If the PC | |
475 | is in the function prologue, we only consider the part that | |
476 | has executed already. */ | |
477 | ||
478 | ip = get_pc_function_start (fi->pc); | |
479 | sal = find_pc_line (ip, 0); | |
480 | limit = (sal.end && sal.end < fi->pc) ? sal.end: fi->pc; | |
481 | ||
482 | /* This will fill in fields in *fi as well as in cache_fsr. */ | |
483 | examine_prologue (ip, limit, fi->frame, cache_fsr, fi); | |
8aa13b87 JK |
484 | } |
485 | ||
ea3c0839 JG |
486 | if (fsr) |
487 | *fsr = *fi->fsr; | |
488 | } | |
489 | ||
490 | /* Return the address of the locals block for the frame | |
491 | described by FI. Returns 0 if the address is unknown. | |
492 | NOTE! Frame locals are referred to by negative offsets from the | |
493 | argument pointer, so this is the same as frame_args_address(). */ | |
494 | ||
495 | CORE_ADDR | |
496 | frame_locals_address (fi) | |
497 | struct frame_info *fi; | |
498 | { | |
ea3c0839 | 499 | struct frame_saved_regs fsr; |
ea3c0839 JG |
500 | |
501 | if (fi->args_pointer) /* Cached value is likely there. */ | |
502 | return fi->args_pointer; | |
503 | ||
504 | /* Nope, generate it. */ | |
505 | ||
506 | get_frame_saved_regs (fi, &fsr); | |
507 | ||
508 | return fi->args_pointer; | |
509 | } | |
510 | ||
511 | /* Return the address of the argument block for the frame | |
512 | described by FI. Returns 0 if the address is unknown. */ | |
513 | ||
514 | CORE_ADDR | |
515 | frame_args_address (fi) | |
516 | struct frame_info *fi; | |
517 | { | |
ea3c0839 | 518 | struct frame_saved_regs fsr; |
ea3c0839 JG |
519 | |
520 | if (fi->args_pointer) /* Cached value is likely there. */ | |
521 | return fi->args_pointer; | |
522 | ||
523 | /* Nope, generate it. */ | |
524 | ||
525 | get_frame_saved_regs (fi, &fsr); | |
526 | ||
527 | return fi->args_pointer; | |
528 | } | |
529 | ||
530 | /* Return the saved PC from this frame. | |
531 | ||
532 | If the frame has a memory copy of SRP_REGNUM, use that. If not, | |
533 | just use the register SRP_REGNUM itself. */ | |
534 | ||
535 | CORE_ADDR | |
536 | frame_saved_pc (frame) | |
537 | FRAME frame; | |
538 | { | |
539 | return read_next_frame_reg(frame, SRP_REGNUM); | |
8aa13b87 JK |
540 | } |
541 | ||
ea3c0839 | 542 | |
ef98d5ac JG |
543 | static int |
544 | pushed_size (prev_words, v) | |
545 | int prev_words; | |
546 | struct value *v; | |
547 | { | |
548 | switch (TYPE_CODE (VALUE_TYPE (v))) | |
549 | { | |
550 | case TYPE_CODE_VOID: /* Void type (values zero length) */ | |
551 | ||
552 | return 0; /* That was easy! */ | |
553 | ||
554 | case TYPE_CODE_PTR: /* Pointer type */ | |
555 | case TYPE_CODE_ENUM: /* Enumeration type */ | |
556 | case TYPE_CODE_INT: /* Integer type */ | |
557 | case TYPE_CODE_REF: /* C++ Reference types */ | |
85f0a848 | 558 | case TYPE_CODE_ARRAY: /* Array type, lower & upper bounds */ |
ef98d5ac JG |
559 | |
560 | return 1; | |
561 | ||
562 | case TYPE_CODE_FLT: /* Floating type */ | |
563 | ||
564 | if (TYPE_LENGTH (VALUE_TYPE (v)) == 4) | |
565 | return 1; | |
566 | else | |
567 | /* Assume that it must be a double. */ | |
568 | if (prev_words & 1) /* at an odd-word boundary */ | |
569 | return 3; /* round to 8-byte boundary */ | |
570 | else | |
571 | return 2; | |
572 | ||
573 | case TYPE_CODE_STRUCT: /* C struct or Pascal record */ | |
574 | case TYPE_CODE_UNION: /* C union or Pascal variant part */ | |
575 | ||
576 | return (((TYPE_LENGTH (VALUE_TYPE (v)) + 3) / 4) * 4); | |
577 | ||
578 | case TYPE_CODE_FUNC: /* Function type */ | |
579 | case TYPE_CODE_SET: /* Pascal sets */ | |
580 | case TYPE_CODE_RANGE: /* Range (integers within bounds) */ | |
c4413e2c | 581 | case TYPE_CODE_STRING: /* String type */ |
ef98d5ac JG |
582 | case TYPE_CODE_MEMBER: /* Member type */ |
583 | case TYPE_CODE_METHOD: /* Method type */ | |
584 | /* Don't know how to pass these yet. */ | |
585 | ||
586 | case TYPE_CODE_UNDEF: /* Not used; catches errors */ | |
587 | default: | |
588 | abort (); | |
589 | } | |
590 | } | |
591 | ||
592 | static void | |
593 | store_parm_word (address, val) | |
594 | CORE_ADDR address; | |
595 | int val; | |
596 | { | |
2a770cac | 597 | write_memory (address, (char *)&val, 4); |
ef98d5ac JG |
598 | } |
599 | ||
600 | static int | |
601 | store_parm (prev_words, left_parm_addr, v) | |
602 | unsigned int prev_words; | |
603 | CORE_ADDR left_parm_addr; | |
604 | struct value *v; | |
605 | { | |
606 | CORE_ADDR start = left_parm_addr + (prev_words * 4); | |
607 | int *val_addr = (int *)VALUE_CONTENTS(v); | |
608 | ||
609 | switch (TYPE_CODE (VALUE_TYPE (v))) | |
610 | { | |
611 | case TYPE_CODE_VOID: /* Void type (values zero length) */ | |
612 | ||
613 | return 0; | |
614 | ||
615 | case TYPE_CODE_PTR: /* Pointer type */ | |
616 | case TYPE_CODE_ENUM: /* Enumeration type */ | |
617 | case TYPE_CODE_INT: /* Integer type */ | |
85f0a848 | 618 | case TYPE_CODE_ARRAY: /* Array type, lower & upper bounds */ |
ef98d5ac JG |
619 | case TYPE_CODE_REF: /* C++ Reference types */ |
620 | ||
621 | store_parm_word (start, *val_addr); | |
622 | return 1; | |
623 | ||
624 | case TYPE_CODE_FLT: /* Floating type */ | |
625 | ||
626 | if (TYPE_LENGTH (VALUE_TYPE (v)) == 4) | |
627 | { | |
628 | store_parm_word (start, *val_addr); | |
629 | return 1; | |
630 | } | |
631 | else | |
632 | { | |
633 | store_parm_word (start + ((prev_words & 1) * 4), val_addr[0]); | |
634 | store_parm_word (start + ((prev_words & 1) * 4) + 4, val_addr[1]); | |
635 | return 2 + (prev_words & 1); | |
636 | } | |
637 | ||
638 | case TYPE_CODE_STRUCT: /* C struct or Pascal record */ | |
639 | case TYPE_CODE_UNION: /* C union or Pascal variant part */ | |
640 | ||
641 | { | |
642 | unsigned int words = (((TYPE_LENGTH (VALUE_TYPE (v)) + 3) / 4) * 4); | |
643 | unsigned int word; | |
644 | ||
645 | for (word = 0; word < words; word++) | |
646 | store_parm_word (start + (word * 4), val_addr[word]); | |
647 | return words; | |
648 | } | |
649 | ||
650 | default: | |
651 | abort (); | |
652 | } | |
653 | } | |
8aa13b87 | 654 | |
8aa13b87 JK |
655 | /* This routine sets up all of the parameter values needed to make a pseudo |
656 | call. The name "push_parameters" is a misnomer on some archs, | |
657 | because (on the m88k) most parameters generally end up being passed in | |
658 | registers rather than on the stack. In this routine however, we do | |
659 | end up storing *all* parameter values onto the stack (even if we will | |
660 | realize later that some of these stores were unnecessary). */ | |
661 | ||
ea3c0839 JG |
662 | #define FIRST_PARM_REGNUM 2 |
663 | ||
8aa13b87 JK |
664 | void |
665 | push_parameters (return_type, struct_conv, nargs, args) | |
666 | struct type *return_type; | |
667 | int struct_conv; | |
668 | int nargs; | |
669 | value *args; | |
ea3c0839 | 670 | { |
8aa13b87 JK |
671 | int parm_num; |
672 | unsigned int p_words = 0; | |
673 | CORE_ADDR left_parm_addr; | |
674 | ||
675 | /* Start out by creating a space for the return value (if need be). We | |
676 | only need to do this if the return value is a struct or union. If we | |
677 | do make a space for a struct or union return value, then we must also | |
678 | arrange for the base address of that space to go into r12, which is the | |
679 | standard place to pass the address of the return value area to the | |
680 | callee. Note that only structs and unions are returned in this fashion. | |
681 | Ints, enums, pointers, and floats are returned into r2. Doubles are | |
682 | returned into the register pair {r2,r3}. Note also that the space | |
683 | reserved for a struct or union return value only has to be word aligned | |
684 | (not double-word) but it is double-word aligned here anyway (just in | |
685 | case that becomes important someday). */ | |
686 | ||
687 | switch (TYPE_CODE (return_type)) | |
688 | { | |
689 | case TYPE_CODE_STRUCT: | |
690 | case TYPE_CODE_UNION: | |
691 | { | |
692 | int return_bytes = ((TYPE_LENGTH (return_type) + 7) / 8) * 8; | |
693 | CORE_ADDR rv_addr; | |
694 | ||
695 | rv_addr = read_register (SP_REGNUM) - return_bytes; | |
696 | ||
697 | write_register (SP_REGNUM, rv_addr); /* push space onto the stack */ | |
698 | write_register (SRA_REGNUM, rv_addr);/* set return value register */ | |
817ac7f8 | 699 | break; |
8aa13b87 | 700 | } |
817ac7f8 | 701 | default: break; |
8aa13b87 JK |
702 | } |
703 | ||
704 | /* Here we make a pre-pass on the whole parameter list to figure out exactly | |
705 | how many words worth of stuff we are going to pass. */ | |
706 | ||
707 | for (p_words = 0, parm_num = 0; parm_num < nargs; parm_num++) | |
708 | p_words += pushed_size (p_words, value_arg_coerce (args[parm_num])); | |
709 | ||
710 | /* Now, check to see if we have to round up the number of parameter words | |
711 | to get up to the next 8-bytes boundary. This may be necessary because | |
712 | of the software convention to always keep the stack aligned on an 8-byte | |
713 | boundary. */ | |
714 | ||
715 | if (p_words & 1) | |
716 | p_words++; /* round to 8-byte boundary */ | |
717 | ||
718 | /* Now figure out the absolute address of the leftmost parameter, and update | |
719 | the stack pointer to point at that address. */ | |
720 | ||
721 | left_parm_addr = read_register (SP_REGNUM) - (p_words * 4); | |
722 | write_register (SP_REGNUM, left_parm_addr); | |
723 | ||
724 | /* Now we can go through all of the parameters (in left-to-right order) | |
725 | and write them to their parameter stack slots. Note that we are not | |
726 | really "pushing" the parameter values. The stack space for these values | |
727 | was already allocated above. Now we are just filling it up. */ | |
728 | ||
729 | for (p_words = 0, parm_num = 0; parm_num < nargs; parm_num++) | |
730 | p_words += | |
731 | store_parm (p_words, left_parm_addr, value_arg_coerce (args[parm_num])); | |
732 | ||
733 | /* Now that we are all done storing the parameter values into the stack, we | |
734 | must go back and load up the parameter registers with the values from the | |
735 | corresponding stack slots. Note that in the two cases of (a) gaps in the | |
736 | parameter word sequence causes by (otherwise) misaligned doubles, and (b) | |
737 | slots correcponding to structs or unions, the work we do here in loading | |
738 | some parameter registers may be unnecessary, but who cares? */ | |
739 | ||
740 | for (p_words = 0; p_words < 8; p_words++) | |
741 | { | |
742 | write_register (FIRST_PARM_REGNUM + p_words, | |
743 | read_memory_integer (left_parm_addr + (p_words * 4), 4)); | |
744 | } | |
745 | } | |
746 | ||
747 | void | |
748 | pop_frame () | |
749 | { | |
750 | error ("Feature not implemented for the m88k yet."); | |
751 | return; | |
752 | } | |
753 | ||
ea3c0839 JG |
754 | void |
755 | collect_returned_value (rval, value_type, struct_return, nargs, args) | |
756 | value *rval; | |
757 | struct type *value_type; | |
758 | int struct_return; | |
759 | int nargs; | |
760 | value *args; | |
761 | { | |
762 | char retbuf[REGISTER_BYTES]; | |
763 | ||
ade40d31 | 764 | memcpy (retbuf, registers, REGISTER_BYTES); |
ea3c0839 JG |
765 | *rval = value_being_returned (value_type, retbuf, struct_return); |
766 | return; | |
767 | } | |
8aa13b87 JK |
768 | |
769 | #if 0 | |
770 | /* Now handled in a machine independent way with CALL_DUMMY_LOCATION. */ | |
771 | /* Stuff a breakpoint instruction onto the stack (or elsewhere if the stack | |
772 | is not a good place for it). Return the address at which the instruction | |
773 | got stuffed, or zero if we were unable to stuff it anywhere. */ | |
774 | ||
ea3c0839 JG |
775 | CORE_ADDR |
776 | push_breakpoint () | |
777 | { | |
778 | static char breakpoint_insn[] = BREAKPOINT; | |
779 | extern CORE_ADDR text_end; /* of inferior */ | |
780 | static char readback_buffer[] = BREAKPOINT; | |
781 | int i; | |
8aa13b87 | 782 | |
ea3c0839 JG |
783 | /* With a little bit of luck, we can just stash the breakpoint instruction |
784 | in the word just beyond the end of normal text space. For systems on | |
785 | which the hardware will not allow us to execute out of the stack segment, | |
786 | we have to hope that we *are* at least allowed to effectively extend the | |
787 | text segment by one word. If the actual end of user's the text segment | |
788 | happens to fall right at a page boundary this trick may fail. Note that | |
789 | we check for this by reading after writing, and comparing in order to | |
790 | be sure that the write worked. */ | |
8aa13b87 | 791 | |
ea3c0839 | 792 | write_memory (text_end, &breakpoint_insn, 4); |
8aa13b87 | 793 | |
ea3c0839 JG |
794 | /* Fill the readback buffer with some garbage which is certain to be |
795 | unequal to the breakpoint insn. That way we can tell if the | |
796 | following read doesn't actually succeed. */ | |
8aa13b87 | 797 | |
ea3c0839 JG |
798 | for (i = 0; i < sizeof (readback_buffer); i++) |
799 | readback_buffer[i] = ~ readback_buffer[i]; /* Invert the bits */ | |
800 | ||
801 | /* Now check that the breakpoint insn was successfully installed. */ | |
8aa13b87 | 802 | |
ea3c0839 JG |
803 | read_memory (text_end, readback_buffer, sizeof (readback_buffer)); |
804 | for (i = 0; i < sizeof (readback_buffer); i++) | |
805 | if (readback_buffer[i] != breakpoint_insn[i]) | |
806 | return 0; /* Failed to install! */ | |
807 | ||
808 | return text_end; | |
8aa13b87 | 809 | } |
ea3c0839 | 810 | #endif |