| 1 | /* Target-machine dependent code for Motorola 88000 series, for GDB. |
| 2 | Copyright (C) 1988, 1990, 1991 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 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 |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "value.h" |
| 24 | |
| 25 | #ifdef USG |
| 26 | #include <sys/types.h> |
| 27 | #endif |
| 28 | |
| 29 | #include <sys/param.h> |
| 30 | #include <sys/dir.h> |
| 31 | #include <signal.h> |
| 32 | #include "gdbcore.h" |
| 33 | #include <sys/user.h> |
| 34 | #ifndef USER /* added to support BCS ptrace_user */ |
| 35 | |
| 36 | #define USER ptrace_user |
| 37 | #endif |
| 38 | #include <sys/ioctl.h> |
| 39 | #include <fcntl.h> |
| 40 | |
| 41 | #include <sys/file.h> |
| 42 | #include <sys/stat.h> |
| 43 | |
| 44 | #include "symtab.h" |
| 45 | #include "setjmp.h" |
| 46 | #include "value.h" |
| 47 | |
| 48 | void frame_find_saved_regs (); |
| 49 | |
| 50 | |
| 51 | /* Given a GDB frame, determine the address of the calling function's frame. |
| 52 | This will be used to create a new GDB frame struct, and then |
| 53 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. |
| 54 | |
| 55 | For us, the frame address is its stack pointer value, so we look up |
| 56 | the function prologue to determine the caller's sp value, and return it. */ |
| 57 | |
| 58 | FRAME_ADDR |
| 59 | frame_chain (thisframe) |
| 60 | FRAME thisframe; |
| 61 | { |
| 62 | |
| 63 | frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0); |
| 64 | /* NOTE: this depends on frame_find_saved_regs returning the VALUE, not |
| 65 | the ADDRESS, of SP_REGNUM. It also depends on the cache of |
| 66 | frame_find_saved_regs results. */ |
| 67 | if (thisframe->fsr->regs[SP_REGNUM]) |
| 68 | return thisframe->fsr->regs[SP_REGNUM]; |
| 69 | else |
| 70 | return thisframe->frame; /* Leaf fn -- next frame up has same SP. */ |
| 71 | } |
| 72 | |
| 73 | int |
| 74 | frameless_function_invocation (frame) |
| 75 | FRAME frame; |
| 76 | { |
| 77 | |
| 78 | frame_find_saved_regs (frame, (struct frame_saved_regs *) 0); |
| 79 | /* NOTE: this depends on frame_find_saved_regs returning the VALUE, not |
| 80 | the ADDRESS, of SP_REGNUM. It also depends on the cache of |
| 81 | frame_find_saved_regs results. */ |
| 82 | if (frame->fsr->regs[SP_REGNUM]) |
| 83 | return 0; /* Frameful -- return addr saved somewhere */ |
| 84 | else |
| 85 | return 1; /* Frameless -- no saved return address */ |
| 86 | } |
| 87 | |
| 88 | int |
| 89 | frame_chain_valid (chain, thisframe) |
| 90 | CORE_ADDR chain; |
| 91 | struct frame_info *thisframe; |
| 92 | { |
| 93 | return (chain != 0 |
| 94 | && !inside_entry_file (FRAME_SAVED_PC (thisframe))); |
| 95 | } |
| 96 | |
| 97 | void |
| 98 | init_extra_frame_info (fromleaf, fi) |
| 99 | int fromleaf; |
| 100 | struct frame_info *fi; |
| 101 | { |
| 102 | fi->fsr = 0; /* Not yet allocated */ |
| 103 | fi->args_pointer = 0; /* Unknown */ |
| 104 | fi->locals_pointer = 0; /* Unknown */ |
| 105 | } |
| 106 | \f |
| 107 | /* Examine an m88k function prologue, recording the addresses at which |
| 108 | registers are saved explicitly by the prologue code, and returning |
| 109 | the address of the first instruction after the prologue (but not |
| 110 | after the instruction at address LIMIT, as explained below). |
| 111 | |
| 112 | LIMIT places an upper bound on addresses of the instructions to be |
| 113 | examined. If the prologue code scan reaches LIMIT, the scan is |
| 114 | aborted and LIMIT is returned. This is used, when examining the |
| 115 | prologue for the current frame, to keep examine_prologue () from |
| 116 | claiming that a given register has been saved when in fact the |
| 117 | instruction that saves it has not yet been executed. LIMIT is used |
| 118 | at other times to stop the scan when we hit code after the true |
| 119 | function prologue (e.g. for the first source line) which might |
| 120 | otherwise be mistaken for function prologue. |
| 121 | |
| 122 | The format of the function prologue matched by this routine is |
| 123 | derived from examination of the source to gcc 1.95, particularly |
| 124 | the routine output_prologue () in config/out-m88k.c. |
| 125 | |
| 126 | subu r31,r31,n # stack pointer update |
| 127 | |
| 128 | (st rn,r31,offset)? # save incoming regs |
| 129 | (st.d rn,r31,offset)? |
| 130 | |
| 131 | (addu r30,r31,n)? # frame pointer update |
| 132 | |
| 133 | (pic sequence)? # PIC code prologue |
| 134 | |
| 135 | (or rn,rm,0)? # Move parameters to other regs |
| 136 | */ |
| 137 | |
| 138 | /* Macros for extracting fields from instructions. */ |
| 139 | |
| 140 | #define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos)) |
| 141 | #define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width)) |
| 142 | |
| 143 | /* Prologue code that handles position-independent-code setup. */ |
| 144 | |
| 145 | struct pic_prologue_code { |
| 146 | unsigned long insn, mask; |
| 147 | }; |
| 148 | |
| 149 | static struct pic_prologue_code pic_prologue_code [] = { |
| 150 | /* FIXME -- until this is translated to hex, we won't match it... */ |
| 151 | 0xffffffff, 0, |
| 152 | /* or r10,r1,0 (if not saved) */ |
| 153 | /* bsr.n LabN */ |
| 154 | /* or.u r25,r0,const */ |
| 155 | /*LabN: or r25,r25,const2 */ |
| 156 | /* addu r25,r25,1 */ |
| 157 | /* or r1,r10,0 (if not saved) */ |
| 158 | }; |
| 159 | |
| 160 | /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or |
| 161 | is not the address of a valid instruction, the address of the next |
| 162 | instruction beyond ADDR otherwise. *PWORD1 receives the first word |
| 163 | of the instruction. PWORD2 is ignored -- a remnant of the original |
| 164 | i960 version. */ |
| 165 | |
| 166 | #define NEXT_PROLOGUE_INSN(addr, lim, pword1, pword2) \ |
| 167 | (((addr) < (lim)) ? next_insn (addr, pword1) : 0) |
| 168 | |
| 169 | /* Read the m88k instruction at 'memaddr' and return the address of |
| 170 | the next instruction after that, or 0 if 'memaddr' is not the |
| 171 | address of a valid instruction. The instruction |
| 172 | is stored at 'pword1'. */ |
| 173 | |
| 174 | CORE_ADDR |
| 175 | next_insn (memaddr, pword1) |
| 176 | unsigned long *pword1; |
| 177 | CORE_ADDR memaddr; |
| 178 | { |
| 179 | unsigned long buf[1]; |
| 180 | |
| 181 | read_memory (memaddr, buf, sizeof (buf)); |
| 182 | *pword1 = buf[0]; |
| 183 | SWAP_TARGET_AND_HOST (pword1, sizeof (long)); |
| 184 | |
| 185 | return memaddr + 4; |
| 186 | } |
| 187 | |
| 188 | /* Read a register from frames called by us (or from the hardware regs). */ |
| 189 | |
| 190 | int |
| 191 | read_next_frame_reg(fi, regno) |
| 192 | FRAME fi; |
| 193 | int regno; |
| 194 | { |
| 195 | for (; fi; fi = fi->next) { |
| 196 | if (regno == SP_REGNUM) return fi->frame; |
| 197 | else if (fi->fsr->regs[regno]) |
| 198 | return read_memory_integer(fi->fsr->regs[regno], 4); |
| 199 | } |
| 200 | return read_register(regno); |
| 201 | } |
| 202 | |
| 203 | /* Examine the prologue of a function. `ip' points to the first instruction. |
| 204 | `limit' is the limit of the prologue (e.g. the addr of the first |
| 205 | linenumber, or perhaps the program counter if we're stepping through). |
| 206 | `frame_sp' is the stack pointer value in use in this frame. |
| 207 | `fsr' is a pointer to a frame_saved_regs structure into which we put |
| 208 | info about the registers saved by this frame. |
| 209 | `fi' is a struct frame_info pointer; we fill in various fields in it |
| 210 | to reflect the offsets of the arg pointer and the locals pointer. */ |
| 211 | |
| 212 | static CORE_ADDR |
| 213 | examine_prologue (ip, limit, frame_sp, fsr, fi) |
| 214 | register CORE_ADDR ip; |
| 215 | register CORE_ADDR limit; |
| 216 | FRAME_ADDR frame_sp; |
| 217 | struct frame_saved_regs *fsr; |
| 218 | struct frame_info *fi; |
| 219 | { |
| 220 | register CORE_ADDR next_ip; |
| 221 | register int src; |
| 222 | register struct pic_prologue_code *pcode; |
| 223 | unsigned int insn1, insn2; |
| 224 | int size, offset; |
| 225 | char must_adjust[32]; /* If set, must adjust offsets in fsr */ |
| 226 | int sp_offset = -1; /* -1 means not set (valid must be mult of 8) */ |
| 227 | int fp_offset = -1; /* -1 means not set */ |
| 228 | CORE_ADDR frame_fp; |
| 229 | |
| 230 | bzero (must_adjust, sizeof (must_adjust)); |
| 231 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 232 | |
| 233 | /* Accept move of incoming registers to other registers, using |
| 234 | "or rd,rs,0" or "or.u rd,rs,0" or "or rd,r0,rs" or "or rd,rs,r0". |
| 235 | We don't have to worry about walking into the first lines of code, |
| 236 | since the first line number will stop us (assuming we have symbols). |
| 237 | What we have actually seen is "or r10,r0,r12". */ |
| 238 | |
| 239 | #define OR_MOVE_INSN 0x58000000 /* or/or.u with immed of 0 */ |
| 240 | #define OR_MOVE_MASK 0xF800FFFF |
| 241 | #define OR_REG_MOVE1_INSN 0xF4005800 /* or rd,r0,rs */ |
| 242 | #define OR_REG_MOVE1_MASK 0xFC1FFFE0 |
| 243 | #define OR_REG_MOVE2_INSN 0xF4005800 /* or rd,rs,r0 */ |
| 244 | #define OR_REG_MOVE2_MASK 0xFC00FFFF |
| 245 | while (next_ip && |
| 246 | ((insn1 & OR_MOVE_MASK) == OR_MOVE_INSN || |
| 247 | (insn1 & OR_REG_MOVE1_MASK) == OR_REG_MOVE1_INSN || |
| 248 | (insn1 & OR_REG_MOVE2_MASK) == OR_REG_MOVE2_INSN |
| 249 | ) |
| 250 | ) |
| 251 | { |
| 252 | /* We don't care what moves to where. The result of the moves |
| 253 | has already been reflected in what the compiler tells us is the |
| 254 | location of these parameters. */ |
| 255 | ip = next_ip; |
| 256 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 257 | } |
| 258 | |
| 259 | /* Accept an optional "subu sp,sp,n" to set up the stack pointer. */ |
| 260 | |
| 261 | #define SUBU_SP_INSN 0x67ff0000 |
| 262 | #define SUBU_SP_MASK 0xffff0007 /* Note offset must be mult. of 8 */ |
| 263 | #define SUBU_OFFSET(x) ((unsigned)(x & 0xFFFF)) |
| 264 | if (next_ip && |
| 265 | ((insn1 & SUBU_SP_MASK) == SUBU_SP_INSN)) /* subu r31, r31, N */ |
| 266 | { |
| 267 | sp_offset = -SUBU_OFFSET (insn1); |
| 268 | ip = next_ip; |
| 269 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 270 | } |
| 271 | |
| 272 | /* The function must start with a stack-pointer adjustment, or |
| 273 | we don't know WHAT'S going on... */ |
| 274 | if (sp_offset == -1) |
| 275 | return ip; |
| 276 | |
| 277 | /* Accept zero or more instances of "st rx,sp,n" or "st.d rx,sp,n". |
| 278 | This may cause us to mistake the copying of a register |
| 279 | parameter to the frame for the saving of a callee-saved |
| 280 | register, but that can't be helped, since with the |
| 281 | "-fcall-saved" flag, any register can be made callee-saved. |
| 282 | This probably doesn't matter, since the ``saved'' caller's values of |
| 283 | non-callee-saved registers are not relevant anyway. */ |
| 284 | |
| 285 | #define STD_STACK_INSN 0x201f0000 |
| 286 | #define STD_STACK_MASK 0xfc1f0000 |
| 287 | #define ST_STACK_INSN 0x241f0000 |
| 288 | #define ST_STACK_MASK 0xfc1f0000 |
| 289 | #define ST_OFFSET(x) ((unsigned)((x) & 0xFFFF)) |
| 290 | #define ST_SRC(x) EXTRACT_FIELD ((x), 21, 5) |
| 291 | |
| 292 | while (next_ip) |
| 293 | { |
| 294 | if ((insn1 & ST_STACK_MASK) == ST_STACK_INSN) |
| 295 | size = 1; |
| 296 | else if ((insn1 & STD_STACK_MASK) == STD_STACK_INSN) |
| 297 | size = 2; |
| 298 | else |
| 299 | break; |
| 300 | |
| 301 | src = ST_SRC (insn1); |
| 302 | offset = ST_OFFSET (insn1); |
| 303 | while (size--) |
| 304 | { |
| 305 | must_adjust[src] = 1; |
| 306 | fsr->regs[src++] = offset; /* Will be adjusted later */ |
| 307 | offset += 4; |
| 308 | } |
| 309 | ip = next_ip; |
| 310 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 311 | } |
| 312 | |
| 313 | /* Accept an optional "addu r30,r31,n" to set up the frame pointer. */ |
| 314 | |
| 315 | #define ADDU_FP_INSN 0x63df0000 |
| 316 | #define ADDU_FP_MASK 0xffff0000 |
| 317 | #define ADDU_OFFSET(x) ((unsigned)(x & 0xFFFF)) |
| 318 | if (next_ip && |
| 319 | ((insn1 & ADDU_FP_MASK) == ADDU_FP_INSN)) /* addu r30, r31, N */ |
| 320 | { |
| 321 | fp_offset = ADDU_OFFSET (insn1); |
| 322 | ip = next_ip; |
| 323 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 324 | } |
| 325 | |
| 326 | /* Accept the PIC prologue code if present. */ |
| 327 | |
| 328 | pcode = pic_prologue_code; |
| 329 | size = sizeof (pic_prologue_code) / sizeof (*pic_prologue_code); |
| 330 | /* If return addr is saved, we don't use first or last insn of PICstuff. */ |
| 331 | if (fsr->regs[SRP_REGNUM]) { |
| 332 | pcode++; |
| 333 | size-=2; |
| 334 | } |
| 335 | |
| 336 | while (size-- && next_ip && (pcode->insn == (pcode->mask & insn1))) |
| 337 | { |
| 338 | pcode++; |
| 339 | ip = next_ip; |
| 340 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 341 | } |
| 342 | |
| 343 | /* Accept moves of parameter registers to other registers, using |
| 344 | "or rd,rs,0" or "or.u rd,rs,0" or "or rd,r0,rs" or "or rd,rs,r0". |
| 345 | We don't have to worry about walking into the first lines of code, |
| 346 | since the first line number will stop us (assuming we have symbols). |
| 347 | What gcc actually seems to produce is "or rd,r0,rs". */ |
| 348 | |
| 349 | #define OR_MOVE_INSN 0x58000000 /* or/or.u with immed of 0 */ |
| 350 | #define OR_MOVE_MASK 0xF800FFFF |
| 351 | #define OR_REG_MOVE1_INSN 0xF4005800 /* or rd,r0,rs */ |
| 352 | #define OR_REG_MOVE1_MASK 0xFC1FFFE0 |
| 353 | #define OR_REG_MOVE2_INSN 0xF4005800 /* or rd,rs,r0 */ |
| 354 | #define OR_REG_MOVE2_MASK 0xFC00FFFF |
| 355 | while (next_ip && |
| 356 | ((insn1 & OR_MOVE_MASK) == OR_MOVE_INSN || |
| 357 | (insn1 & OR_REG_MOVE1_MASK) == OR_REG_MOVE1_INSN || |
| 358 | (insn1 & OR_REG_MOVE2_MASK) == OR_REG_MOVE2_INSN |
| 359 | ) |
| 360 | ) |
| 361 | { |
| 362 | /* We don't care what moves to where. The result of the moves |
| 363 | has already been reflected in what the compiler tells us is the |
| 364 | location of these parameters. */ |
| 365 | ip = next_ip; |
| 366 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2); |
| 367 | } |
| 368 | |
| 369 | /* We're done with the prologue. If we don't care about the stack |
| 370 | frame itself, just return. (Note that fsr->regs has been trashed, |
| 371 | but the one caller who calls with fi==0 passes a dummy there.) */ |
| 372 | |
| 373 | if (fi == 0) |
| 374 | return ip; |
| 375 | |
| 376 | /* OK, now we have: |
| 377 | sp_offset original negative displacement of SP |
| 378 | fp_offset positive displacement between new SP and new FP, or -1 |
| 379 | fsr->regs[0..31] offset from original SP where reg is stored |
| 380 | must_adjust[0..31] set if corresp. offset was set |
| 381 | |
| 382 | The current SP (frame_sp) might not be the original new SP as set |
| 383 | by the function prologue, if alloca has been called. This can |
| 384 | only occur if fp_offset is set, though (the compiler allocates an |
| 385 | FP when it sees alloca). In that case, we have the FP, |
| 386 | and can calculate the original new SP from the FP. |
| 387 | |
| 388 | Then, we figure out where the arguments and locals are, and |
| 389 | relocate the offsets in fsr->regs to absolute addresses. */ |
| 390 | |
| 391 | if (fp_offset != -1) { |
| 392 | /* We have a frame pointer, so get it, and base our calc's on it. */ |
| 393 | frame_fp = (CORE_ADDR) read_next_frame_reg (fi->next, FP_REGNUM); |
| 394 | frame_sp = frame_fp - fp_offset; |
| 395 | } else { |
| 396 | /* We have no frame pointer, therefore frame_sp is still the same value |
| 397 | as set by prologue. But where is the frame itself? */ |
| 398 | if (must_adjust[SRP_REGNUM]) { |
| 399 | /* Function header saved SRP (r1), the return address. Frame starts |
| 400 | 4 bytes down from where it was saved. */ |
| 401 | frame_fp = frame_sp + fsr->regs[SRP_REGNUM] - 4; |
| 402 | fi->locals_pointer = frame_fp; |
| 403 | } else { |
| 404 | /* Function header didn't save SRP (r1), so we are in a leaf fn or |
| 405 | are otherwise confused. */ |
| 406 | frame_fp = -1; |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | /* The locals are relative to the FP (whether it exists as an allocated |
| 411 | register, or just as an assumed offset from the SP) */ |
| 412 | fi->locals_pointer = frame_fp; |
| 413 | |
| 414 | /* The arguments are just above the SP as it was before we adjusted it |
| 415 | on entry. */ |
| 416 | fi->args_pointer = frame_sp - sp_offset; |
| 417 | |
| 418 | /* Now that we know the SP value used by the prologue, we know where |
| 419 | it saved all the registers. */ |
| 420 | for (src = 0; src < 32; src++) |
| 421 | if (must_adjust[src]) |
| 422 | fsr->regs[src] += frame_sp; |
| 423 | |
| 424 | /* The saved value of the SP is always known. */ |
| 425 | /* (we hope...) */ |
| 426 | if (fsr->regs[SP_REGNUM] != 0 |
| 427 | && fsr->regs[SP_REGNUM] != frame_sp - sp_offset) |
| 428 | fprintf(stderr, "Bad saved SP value %x != %x, offset %x!\n", |
| 429 | fsr->regs[SP_REGNUM], |
| 430 | frame_sp - sp_offset, sp_offset); |
| 431 | |
| 432 | fsr->regs[SP_REGNUM] = frame_sp - sp_offset; |
| 433 | |
| 434 | return (ip); |
| 435 | } |
| 436 | |
| 437 | /* Given an ip value corresponding to the start of a function, |
| 438 | return the ip of the first instruction after the function |
| 439 | prologue. */ |
| 440 | |
| 441 | CORE_ADDR |
| 442 | skip_prologue (ip) |
| 443 | CORE_ADDR (ip); |
| 444 | { |
| 445 | struct frame_saved_regs saved_regs_dummy; |
| 446 | struct symtab_and_line sal; |
| 447 | CORE_ADDR limit; |
| 448 | |
| 449 | sal = find_pc_line (ip, 0); |
| 450 | limit = (sal.end) ? sal.end : 0xffffffff; |
| 451 | |
| 452 | return (examine_prologue (ip, limit, (FRAME_ADDR) 0, &saved_regs_dummy, |
| 453 | (struct frame_info *)0 )); |
| 454 | } |
| 455 | |
| 456 | /* Put here the code to store, into a struct frame_saved_regs, |
| 457 | the addresses of the saved registers of frame described by FRAME_INFO. |
| 458 | This includes special registers such as pc and fp saved in special |
| 459 | ways in the stack frame. sp is even more special: |
| 460 | the address we return for it IS the sp for the next frame. |
| 461 | |
| 462 | We cache the result of doing this in the frame_cache_obstack, since |
| 463 | it is fairly expensive. */ |
| 464 | |
| 465 | void |
| 466 | frame_find_saved_regs (fi, fsr) |
| 467 | struct frame_info *fi; |
| 468 | struct frame_saved_regs *fsr; |
| 469 | { |
| 470 | register CORE_ADDR next_addr; |
| 471 | register CORE_ADDR *saved_regs; |
| 472 | register int regnum; |
| 473 | register struct frame_saved_regs *cache_fsr; |
| 474 | extern struct obstack frame_cache_obstack; |
| 475 | CORE_ADDR ip; |
| 476 | struct symtab_and_line sal; |
| 477 | CORE_ADDR limit; |
| 478 | |
| 479 | if (!fi->fsr) |
| 480 | { |
| 481 | cache_fsr = (struct frame_saved_regs *) |
| 482 | obstack_alloc (&frame_cache_obstack, |
| 483 | sizeof (struct frame_saved_regs)); |
| 484 | bzero (cache_fsr, sizeof (struct frame_saved_regs)); |
| 485 | fi->fsr = cache_fsr; |
| 486 | |
| 487 | /* Find the start and end of the function prologue. If the PC |
| 488 | is in the function prologue, we only consider the part that |
| 489 | has executed already. */ |
| 490 | |
| 491 | ip = get_pc_function_start (fi->pc); |
| 492 | sal = find_pc_line (ip, 0); |
| 493 | limit = (sal.end && sal.end < fi->pc) ? sal.end: fi->pc; |
| 494 | |
| 495 | /* This will fill in fields in *fi as well as in cache_fsr. */ |
| 496 | examine_prologue (ip, limit, fi->frame, cache_fsr, fi); |
| 497 | } |
| 498 | |
| 499 | if (fsr) |
| 500 | *fsr = *fi->fsr; |
| 501 | } |
| 502 | |
| 503 | /* Return the address of the locals block for the frame |
| 504 | described by FI. Returns 0 if the address is unknown. |
| 505 | NOTE! Frame locals are referred to by negative offsets from the |
| 506 | argument pointer, so this is the same as frame_args_address(). */ |
| 507 | |
| 508 | CORE_ADDR |
| 509 | frame_locals_address (fi) |
| 510 | struct frame_info *fi; |
| 511 | { |
| 512 | register FRAME frame; |
| 513 | struct frame_saved_regs fsr; |
| 514 | CORE_ADDR ap; |
| 515 | |
| 516 | if (fi->args_pointer) /* Cached value is likely there. */ |
| 517 | return fi->args_pointer; |
| 518 | |
| 519 | /* Nope, generate it. */ |
| 520 | |
| 521 | get_frame_saved_regs (fi, &fsr); |
| 522 | |
| 523 | return fi->args_pointer; |
| 524 | } |
| 525 | |
| 526 | /* Return the address of the argument block for the frame |
| 527 | described by FI. Returns 0 if the address is unknown. */ |
| 528 | |
| 529 | CORE_ADDR |
| 530 | frame_args_address (fi) |
| 531 | struct frame_info *fi; |
| 532 | { |
| 533 | register FRAME frame; |
| 534 | struct frame_saved_regs fsr; |
| 535 | CORE_ADDR ap; |
| 536 | |
| 537 | if (fi->args_pointer) /* Cached value is likely there. */ |
| 538 | return fi->args_pointer; |
| 539 | |
| 540 | /* Nope, generate it. */ |
| 541 | |
| 542 | get_frame_saved_regs (fi, &fsr); |
| 543 | |
| 544 | return fi->args_pointer; |
| 545 | } |
| 546 | |
| 547 | /* Return the saved PC from this frame. |
| 548 | |
| 549 | If the frame has a memory copy of SRP_REGNUM, use that. If not, |
| 550 | just use the register SRP_REGNUM itself. */ |
| 551 | |
| 552 | CORE_ADDR |
| 553 | frame_saved_pc (frame) |
| 554 | FRAME frame; |
| 555 | { |
| 556 | return read_next_frame_reg(frame, SRP_REGNUM); |
| 557 | } |
| 558 | |
| 559 | |
| 560 | #if TARGET_BYTE_ORDER != HOST_BYTE_ORDER |
| 561 | you lose |
| 562 | #else /* Host and target byte order the same. */ |
| 563 | #define SINGLE_EXP_BITS 8 |
| 564 | #define DOUBLE_EXP_BITS 11 |
| 565 | int |
| 566 | IEEE_isNAN(fp, len) |
| 567 | int *fp, len; |
| 568 | /* fp points to a single precision OR double precision |
| 569 | * floating point value; len is the number of bytes, either 4 or 8. |
| 570 | * Returns 1 iff fp points to a valid IEEE floating point number. |
| 571 | * Returns 0 if fp points to a denormalized number or a NaN |
| 572 | */ |
| 573 | { |
| 574 | int exponent; |
| 575 | if (len == 4) |
| 576 | { |
| 577 | exponent = *fp; |
| 578 | exponent = exponent << 1 >> (32 - SINGLE_EXP_BITS - 1); |
| 579 | return ((exponent == -1) || (! exponent && *fp)); |
| 580 | } |
| 581 | else if (len == 8) |
| 582 | { |
| 583 | exponent = *(fp+1); |
| 584 | exponent = exponent << 1 >> (32 - DOUBLE_EXP_BITS - 1); |
| 585 | return ((exponent == -1) || (! exponent && *fp * *(fp+1))); |
| 586 | } |
| 587 | else return 1; |
| 588 | } |
| 589 | #endif /* Host and target byte order the same. */ |
| 590 | |
| 591 | static int |
| 592 | pushed_size (prev_words, v) |
| 593 | int prev_words; |
| 594 | struct value *v; |
| 595 | { |
| 596 | switch (TYPE_CODE (VALUE_TYPE (v))) |
| 597 | { |
| 598 | case TYPE_CODE_VOID: /* Void type (values zero length) */ |
| 599 | |
| 600 | return 0; /* That was easy! */ |
| 601 | |
| 602 | case TYPE_CODE_PTR: /* Pointer type */ |
| 603 | case TYPE_CODE_ENUM: /* Enumeration type */ |
| 604 | case TYPE_CODE_INT: /* Integer type */ |
| 605 | case TYPE_CODE_REF: /* C++ Reference types */ |
| 606 | case TYPE_CODE_ARRAY: /* Array type, lower bound zero */ |
| 607 | |
| 608 | return 1; |
| 609 | |
| 610 | case TYPE_CODE_FLT: /* Floating type */ |
| 611 | |
| 612 | if (TYPE_LENGTH (VALUE_TYPE (v)) == 4) |
| 613 | return 1; |
| 614 | else |
| 615 | /* Assume that it must be a double. */ |
| 616 | if (prev_words & 1) /* at an odd-word boundary */ |
| 617 | return 3; /* round to 8-byte boundary */ |
| 618 | else |
| 619 | return 2; |
| 620 | |
| 621 | case TYPE_CODE_STRUCT: /* C struct or Pascal record */ |
| 622 | case TYPE_CODE_UNION: /* C union or Pascal variant part */ |
| 623 | |
| 624 | return (((TYPE_LENGTH (VALUE_TYPE (v)) + 3) / 4) * 4); |
| 625 | |
| 626 | case TYPE_CODE_FUNC: /* Function type */ |
| 627 | case TYPE_CODE_SET: /* Pascal sets */ |
| 628 | case TYPE_CODE_RANGE: /* Range (integers within bounds) */ |
| 629 | case TYPE_CODE_PASCAL_ARRAY: /* Array with explicit type of index */ |
| 630 | case TYPE_CODE_MEMBER: /* Member type */ |
| 631 | case TYPE_CODE_METHOD: /* Method type */ |
| 632 | /* Don't know how to pass these yet. */ |
| 633 | |
| 634 | case TYPE_CODE_UNDEF: /* Not used; catches errors */ |
| 635 | default: |
| 636 | abort (); |
| 637 | } |
| 638 | } |
| 639 | |
| 640 | static void |
| 641 | store_parm_word (address, val) |
| 642 | CORE_ADDR address; |
| 643 | int val; |
| 644 | { |
| 645 | write_memory (address, &val, 4); |
| 646 | } |
| 647 | |
| 648 | static int |
| 649 | store_parm (prev_words, left_parm_addr, v) |
| 650 | unsigned int prev_words; |
| 651 | CORE_ADDR left_parm_addr; |
| 652 | struct value *v; |
| 653 | { |
| 654 | CORE_ADDR start = left_parm_addr + (prev_words * 4); |
| 655 | int *val_addr = (int *)VALUE_CONTENTS(v); |
| 656 | |
| 657 | switch (TYPE_CODE (VALUE_TYPE (v))) |
| 658 | { |
| 659 | case TYPE_CODE_VOID: /* Void type (values zero length) */ |
| 660 | |
| 661 | return 0; |
| 662 | |
| 663 | case TYPE_CODE_PTR: /* Pointer type */ |
| 664 | case TYPE_CODE_ENUM: /* Enumeration type */ |
| 665 | case TYPE_CODE_INT: /* Integer type */ |
| 666 | case TYPE_CODE_ARRAY: /* Array type, lower bound zero */ |
| 667 | case TYPE_CODE_REF: /* C++ Reference types */ |
| 668 | |
| 669 | store_parm_word (start, *val_addr); |
| 670 | return 1; |
| 671 | |
| 672 | case TYPE_CODE_FLT: /* Floating type */ |
| 673 | |
| 674 | if (TYPE_LENGTH (VALUE_TYPE (v)) == 4) |
| 675 | { |
| 676 | store_parm_word (start, *val_addr); |
| 677 | return 1; |
| 678 | } |
| 679 | else |
| 680 | { |
| 681 | store_parm_word (start + ((prev_words & 1) * 4), val_addr[0]); |
| 682 | store_parm_word (start + ((prev_words & 1) * 4) + 4, val_addr[1]); |
| 683 | return 2 + (prev_words & 1); |
| 684 | } |
| 685 | |
| 686 | case TYPE_CODE_STRUCT: /* C struct or Pascal record */ |
| 687 | case TYPE_CODE_UNION: /* C union or Pascal variant part */ |
| 688 | |
| 689 | { |
| 690 | unsigned int words = (((TYPE_LENGTH (VALUE_TYPE (v)) + 3) / 4) * 4); |
| 691 | unsigned int word; |
| 692 | |
| 693 | for (word = 0; word < words; word++) |
| 694 | store_parm_word (start + (word * 4), val_addr[word]); |
| 695 | return words; |
| 696 | } |
| 697 | |
| 698 | default: |
| 699 | abort (); |
| 700 | } |
| 701 | } |
| 702 | |
| 703 | /* This routine sets up all of the parameter values needed to make a pseudo |
| 704 | call. The name "push_parameters" is a misnomer on some archs, |
| 705 | because (on the m88k) most parameters generally end up being passed in |
| 706 | registers rather than on the stack. In this routine however, we do |
| 707 | end up storing *all* parameter values onto the stack (even if we will |
| 708 | realize later that some of these stores were unnecessary). */ |
| 709 | |
| 710 | #define FIRST_PARM_REGNUM 2 |
| 711 | |
| 712 | void |
| 713 | push_parameters (return_type, struct_conv, nargs, args) |
| 714 | struct type *return_type; |
| 715 | int struct_conv; |
| 716 | int nargs; |
| 717 | value *args; |
| 718 | { |
| 719 | int parm_num; |
| 720 | unsigned int p_words = 0; |
| 721 | CORE_ADDR left_parm_addr; |
| 722 | |
| 723 | /* Start out by creating a space for the return value (if need be). We |
| 724 | only need to do this if the return value is a struct or union. If we |
| 725 | do make a space for a struct or union return value, then we must also |
| 726 | arrange for the base address of that space to go into r12, which is the |
| 727 | standard place to pass the address of the return value area to the |
| 728 | callee. Note that only structs and unions are returned in this fashion. |
| 729 | Ints, enums, pointers, and floats are returned into r2. Doubles are |
| 730 | returned into the register pair {r2,r3}. Note also that the space |
| 731 | reserved for a struct or union return value only has to be word aligned |
| 732 | (not double-word) but it is double-word aligned here anyway (just in |
| 733 | case that becomes important someday). */ |
| 734 | |
| 735 | switch (TYPE_CODE (return_type)) |
| 736 | { |
| 737 | case TYPE_CODE_STRUCT: |
| 738 | case TYPE_CODE_UNION: |
| 739 | { |
| 740 | int return_bytes = ((TYPE_LENGTH (return_type) + 7) / 8) * 8; |
| 741 | CORE_ADDR rv_addr; |
| 742 | |
| 743 | rv_addr = read_register (SP_REGNUM) - return_bytes; |
| 744 | |
| 745 | write_register (SP_REGNUM, rv_addr); /* push space onto the stack */ |
| 746 | write_register (SRA_REGNUM, rv_addr);/* set return value register */ |
| 747 | } |
| 748 | } |
| 749 | |
| 750 | /* Here we make a pre-pass on the whole parameter list to figure out exactly |
| 751 | how many words worth of stuff we are going to pass. */ |
| 752 | |
| 753 | for (p_words = 0, parm_num = 0; parm_num < nargs; parm_num++) |
| 754 | p_words += pushed_size (p_words, value_arg_coerce (args[parm_num])); |
| 755 | |
| 756 | /* Now, check to see if we have to round up the number of parameter words |
| 757 | to get up to the next 8-bytes boundary. This may be necessary because |
| 758 | of the software convention to always keep the stack aligned on an 8-byte |
| 759 | boundary. */ |
| 760 | |
| 761 | if (p_words & 1) |
| 762 | p_words++; /* round to 8-byte boundary */ |
| 763 | |
| 764 | /* Now figure out the absolute address of the leftmost parameter, and update |
| 765 | the stack pointer to point at that address. */ |
| 766 | |
| 767 | left_parm_addr = read_register (SP_REGNUM) - (p_words * 4); |
| 768 | write_register (SP_REGNUM, left_parm_addr); |
| 769 | |
| 770 | /* Now we can go through all of the parameters (in left-to-right order) |
| 771 | and write them to their parameter stack slots. Note that we are not |
| 772 | really "pushing" the parameter values. The stack space for these values |
| 773 | was already allocated above. Now we are just filling it up. */ |
| 774 | |
| 775 | for (p_words = 0, parm_num = 0; parm_num < nargs; parm_num++) |
| 776 | p_words += |
| 777 | store_parm (p_words, left_parm_addr, value_arg_coerce (args[parm_num])); |
| 778 | |
| 779 | /* Now that we are all done storing the parameter values into the stack, we |
| 780 | must go back and load up the parameter registers with the values from the |
| 781 | corresponding stack slots. Note that in the two cases of (a) gaps in the |
| 782 | parameter word sequence causes by (otherwise) misaligned doubles, and (b) |
| 783 | slots correcponding to structs or unions, the work we do here in loading |
| 784 | some parameter registers may be unnecessary, but who cares? */ |
| 785 | |
| 786 | for (p_words = 0; p_words < 8; p_words++) |
| 787 | { |
| 788 | write_register (FIRST_PARM_REGNUM + p_words, |
| 789 | read_memory_integer (left_parm_addr + (p_words * 4), 4)); |
| 790 | } |
| 791 | } |
| 792 | |
| 793 | void |
| 794 | pop_frame () |
| 795 | { |
| 796 | error ("Feature not implemented for the m88k yet."); |
| 797 | return; |
| 798 | } |
| 799 | |
| 800 | void |
| 801 | collect_returned_value (rval, value_type, struct_return, nargs, args) |
| 802 | value *rval; |
| 803 | struct type *value_type; |
| 804 | int struct_return; |
| 805 | int nargs; |
| 806 | value *args; |
| 807 | { |
| 808 | char retbuf[REGISTER_BYTES]; |
| 809 | |
| 810 | bcopy (registers, retbuf, REGISTER_BYTES); |
| 811 | *rval = value_being_returned (value_type, retbuf, struct_return); |
| 812 | return; |
| 813 | } |
| 814 | |
| 815 | #if 0 |
| 816 | /* Now handled in a machine independent way with CALL_DUMMY_LOCATION. */ |
| 817 | /* Stuff a breakpoint instruction onto the stack (or elsewhere if the stack |
| 818 | is not a good place for it). Return the address at which the instruction |
| 819 | got stuffed, or zero if we were unable to stuff it anywhere. */ |
| 820 | |
| 821 | CORE_ADDR |
| 822 | push_breakpoint () |
| 823 | { |
| 824 | static char breakpoint_insn[] = BREAKPOINT; |
| 825 | extern CORE_ADDR text_end; /* of inferior */ |
| 826 | static char readback_buffer[] = BREAKPOINT; |
| 827 | int i; |
| 828 | |
| 829 | /* With a little bit of luck, we can just stash the breakpoint instruction |
| 830 | in the word just beyond the end of normal text space. For systems on |
| 831 | which the hardware will not allow us to execute out of the stack segment, |
| 832 | we have to hope that we *are* at least allowed to effectively extend the |
| 833 | text segment by one word. If the actual end of user's the text segment |
| 834 | happens to fall right at a page boundary this trick may fail. Note that |
| 835 | we check for this by reading after writing, and comparing in order to |
| 836 | be sure that the write worked. */ |
| 837 | |
| 838 | write_memory (text_end, &breakpoint_insn, 4); |
| 839 | |
| 840 | /* Fill the readback buffer with some garbage which is certain to be |
| 841 | unequal to the breakpoint insn. That way we can tell if the |
| 842 | following read doesn't actually succeed. */ |
| 843 | |
| 844 | for (i = 0; i < sizeof (readback_buffer); i++) |
| 845 | readback_buffer[i] = ~ readback_buffer[i]; /* Invert the bits */ |
| 846 | |
| 847 | /* Now check that the breakpoint insn was successfully installed. */ |
| 848 | |
| 849 | read_memory (text_end, readback_buffer, sizeof (readback_buffer)); |
| 850 | for (i = 0; i < sizeof (readback_buffer); i++) |
| 851 | if (readback_buffer[i] != breakpoint_insn[i]) |
| 852 | return 0; /* Failed to install! */ |
| 853 | |
| 854 | return text_end; |
| 855 | } |
| 856 | #endif |