| 1 | /* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger. |
| 2 | Copyright 1996, 1997 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "obstack.h" |
| 24 | #include "target.h" |
| 25 | #include "value.h" |
| 26 | #include "bfd.h" |
| 27 | #include "gdb_string.h" |
| 28 | #include "gdbcore.h" |
| 29 | #include "symfile.h" |
| 30 | |
| 31 | /* Info gleaned from scanning a function's prologue. */ |
| 32 | |
| 33 | struct pifsr /* Info about one saved reg */ |
| 34 | { |
| 35 | int framereg; /* Frame reg (SP or FP) */ |
| 36 | int offset; /* Offset from framereg */ |
| 37 | int reg; /* Saved register number */ |
| 38 | }; |
| 39 | |
| 40 | struct prologue_info |
| 41 | { |
| 42 | int framereg; |
| 43 | int frameoffset; |
| 44 | int start_function; |
| 45 | struct pifsr *pifsrs; |
| 46 | }; |
| 47 | |
| 48 | /* Function: frame_chain |
| 49 | Figure out and return the caller's frame pointer given current |
| 50 | frame_info struct. |
| 51 | |
| 52 | We start out knowing the current pc, current sp, current fp. |
| 53 | We want to determine the caller's fp and caller's pc. To do this |
| 54 | correctly, we have to be able to handle the case where we are in the |
| 55 | middle of the prologue which involves scanning the prologue. |
| 56 | |
| 57 | We don't handle dummy frames yet but we would probably just return the |
| 58 | stack pointer that was in use at the time the function call was made? |
| 59 | */ |
| 60 | |
| 61 | CORE_ADDR |
| 62 | mn10300_frame_chain (fi) |
| 63 | struct frame_info *fi; |
| 64 | { |
| 65 | struct prologue_info pi; |
| 66 | CORE_ADDR callers_pc, callers_fp, curr_sp; |
| 67 | CORE_ADDR past_prologue_addr; |
| 68 | int past_prologue = 1; /* default to being past prologue */ |
| 69 | int n_movm_args = 4; |
| 70 | |
| 71 | struct pifsr *pifsr, *pifsr_tmp; |
| 72 | |
| 73 | /* current pc is fi->pc */ |
| 74 | /* current fp is fi->frame */ |
| 75 | |
| 76 | /* current sp is: */ |
| 77 | curr_sp = read_register (SP_REGNUM); |
| 78 | |
| 79 | /* |
| 80 | printf("curr pc = 0x%x ; curr fp = 0x%x ; curr sp = 0x%x\n", |
| 81 | fi->pc, fi->frame, curr_sp); |
| 82 | */ |
| 83 | |
| 84 | /* first inst after prologue is: */ |
| 85 | past_prologue_addr = mn10300_skip_prologue (fi->pc); |
| 86 | |
| 87 | /* Are we in the prologue? */ |
| 88 | /* Yes if mn10300_skip_prologue returns an address after the |
| 89 | current pc in which case we have to scan prologue */ |
| 90 | if (fi->pc < mn10300_skip_prologue (fi->pc)) |
| 91 | past_prologue = 0; |
| 92 | |
| 93 | /* scan prologue if we're not past it */ |
| 94 | if (!past_prologue) |
| 95 | { |
| 96 | /* printf("scanning prologue\n"); */ |
| 97 | /* FIXME -- fill out this case later */ |
| 98 | return 0x0; /* bogus value */ |
| 99 | } |
| 100 | |
| 101 | if (past_prologue) /* if we don't need to scan the prologue */ |
| 102 | { |
| 103 | /* printf("we're past the prologue\n"); */ |
| 104 | callers_pc = fi->frame - REGISTER_SIZE; |
| 105 | callers_fp = fi->frame - ((n_movm_args + 1) * REGISTER_SIZE); |
| 106 | /* |
| 107 | printf("callers_pc = 0x%x ; callers_fp = 0x%x\n", |
| 108 | callers_pc, callers_fp); |
| 109 | |
| 110 | printf("*callers_pc = 0x%x ; *callers_fp = 0x%x\n", |
| 111 | read_memory_integer(callers_pc, REGISTER_SIZE), |
| 112 | read_memory_integer(callers_fp, REGISTER_SIZE)); |
| 113 | */ |
| 114 | return read_memory_integer(callers_fp, REGISTER_SIZE); |
| 115 | } |
| 116 | |
| 117 | /* we don't get here */ |
| 118 | } |
| 119 | |
| 120 | /* Function: find_callers_reg |
| 121 | Find REGNUM on the stack. Otherwise, it's in an active register. |
| 122 | One thing we might want to do here is to check REGNUM against the |
| 123 | clobber mask, and somehow flag it as invalid if it isn't saved on |
| 124 | the stack somewhere. This would provide a graceful failure mode |
| 125 | when trying to get the value of caller-saves registers for an inner |
| 126 | frame. */ |
| 127 | |
| 128 | CORE_ADDR |
| 129 | mn10300_find_callers_reg (fi, regnum) |
| 130 | struct frame_info *fi; |
| 131 | int regnum; |
| 132 | { |
| 133 | /* printf("mn10300_find_callers_reg\n"); */ |
| 134 | |
| 135 | for (; fi; fi = fi->next) |
| 136 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 137 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); |
| 138 | else if (fi->fsr.regs[regnum] != 0) |
| 139 | return read_memory_unsigned_integer (fi->fsr.regs[regnum], |
| 140 | REGISTER_RAW_SIZE(regnum)); |
| 141 | |
| 142 | return read_register (regnum); |
| 143 | } |
| 144 | |
| 145 | /* Function: skip_prologue |
| 146 | Return the address of the first inst past the prologue of the function. |
| 147 | */ |
| 148 | |
| 149 | CORE_ADDR |
| 150 | mn10300_skip_prologue (pc) |
| 151 | CORE_ADDR pc; |
| 152 | { |
| 153 | CORE_ADDR func_addr, func_end; |
| 154 | |
| 155 | /* printf("mn10300_skip_prologue\n"); */ |
| 156 | |
| 157 | /* See what the symbol table says */ |
| 158 | |
| 159 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) |
| 160 | { |
| 161 | struct symtab_and_line sal; |
| 162 | |
| 163 | sal = find_pc_line (func_addr, 0); |
| 164 | |
| 165 | if (sal.line != 0 && sal.end < func_end) |
| 166 | return sal.end; |
| 167 | else |
| 168 | /* Either there's no line info, or the line after the prologue is after |
| 169 | the end of the function. In this case, there probably isn't a |
| 170 | prologue. */ |
| 171 | return pc; |
| 172 | } |
| 173 | |
| 174 | /* We can't find the start of this function, so there's nothing we can do. */ |
| 175 | return pc; |
| 176 | } |
| 177 | |
| 178 | /* Function: pop_frame |
| 179 | This routine gets called when either the user uses the `return' |
| 180 | command, or the call dummy breakpoint gets hit. */ |
| 181 | |
| 182 | void |
| 183 | mn10300_pop_frame (frame) |
| 184 | struct frame_info *frame; |
| 185 | { |
| 186 | int regnum; |
| 187 | |
| 188 | /* printf("mn10300_pop_frame start\n"); */ |
| 189 | |
| 190 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) |
| 191 | generic_pop_dummy_frame (); |
| 192 | else |
| 193 | { |
| 194 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
| 195 | |
| 196 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 197 | if (frame->fsr.regs[regnum] != 0) |
| 198 | write_register (regnum, |
| 199 | read_memory_unsigned_integer (frame->fsr.regs[regnum], |
| 200 | REGISTER_RAW_SIZE(regnum))); |
| 201 | |
| 202 | write_register (SP_REGNUM, FRAME_FP (frame)); |
| 203 | } |
| 204 | |
| 205 | flush_cached_frames (); |
| 206 | |
| 207 | /* printf("mn10300_pop_frame end\n"); */ |
| 208 | } |
| 209 | |
| 210 | /* Function: push_arguments |
| 211 | Setup arguments for a call to the target. Arguments go in |
| 212 | order on the stack. |
| 213 | */ |
| 214 | |
| 215 | CORE_ADDR |
| 216 | mn10300_push_arguments (nargs, args, sp, struct_return, struct_addr) |
| 217 | int nargs; |
| 218 | value_ptr *args; |
| 219 | CORE_ADDR sp; |
| 220 | unsigned char struct_return; |
| 221 | CORE_ADDR struct_addr; |
| 222 | { |
| 223 | int argnum = 0; |
| 224 | int len = 0; |
| 225 | int stack_offset = 0; /* copy args to this offset onto stack */ |
| 226 | |
| 227 | /* printf("mn10300_push_arguments start\n"); */ |
| 228 | |
| 229 | /* First, just for safety, make sure stack is aligned */ |
| 230 | sp &= ~3; |
| 231 | |
| 232 | /* Now make space on the stack for the args. */ |
| 233 | for (argnum = 0; argnum < nargs; argnum++) |
| 234 | len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3); |
| 235 | |
| 236 | sp -= len; |
| 237 | |
| 238 | /* Push all arguments onto the stack. */ |
| 239 | for (argnum = 0; argnum < nargs; argnum++) |
| 240 | { |
| 241 | int len; |
| 242 | char *val; |
| 243 | |
| 244 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT |
| 245 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) |
| 246 | { |
| 247 | /* for now, pretend structs aren't special */ |
| 248 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| 249 | val = (char *)VALUE_CONTENTS (*args); |
| 250 | } |
| 251 | else |
| 252 | { |
| 253 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| 254 | val = (char *)VALUE_CONTENTS (*args); |
| 255 | } |
| 256 | |
| 257 | while (len > 0) |
| 258 | { |
| 259 | write_memory (sp + stack_offset, val, 4); |
| 260 | |
| 261 | len -= 4; |
| 262 | val += 4; |
| 263 | stack_offset += 4; |
| 264 | } |
| 265 | args++; |
| 266 | } |
| 267 | |
| 268 | /* printf"mn10300_push_arguments end\n"); */ |
| 269 | |
| 270 | return sp; |
| 271 | } |
| 272 | |
| 273 | /* Function: push_return_address (pc) |
| 274 | Set up the return address for the inferior function call. |
| 275 | Needed for targets where we don't actually execute a JSR/BSR instruction */ |
| 276 | |
| 277 | CORE_ADDR |
| 278 | mn10300_push_return_address (pc, sp) |
| 279 | CORE_ADDR pc; |
| 280 | CORE_ADDR sp; |
| 281 | { |
| 282 | /* printf("mn10300_push_return_address\n"); */ |
| 283 | |
| 284 | /* write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); */ |
| 285 | return sp; |
| 286 | } |
| 287 | |
| 288 | /* Function: frame_saved_pc |
| 289 | Find the caller of this frame. We do this by seeing if RP_REGNUM |
| 290 | is saved in the stack anywhere, otherwise we get it from the |
| 291 | registers. If the inner frame is a dummy frame, return its PC |
| 292 | instead of RP, because that's where "caller" of the dummy-frame |
| 293 | will be found. */ |
| 294 | |
| 295 | CORE_ADDR |
| 296 | mn10300_frame_saved_pc (fi) |
| 297 | struct frame_info *fi; |
| 298 | { |
| 299 | /* printf("mn10300_frame_saved_pc\n"); */ |
| 300 | |
| 301 | return (read_memory_integer(fi->frame - REGISTER_SIZE, REGISTER_SIZE)); |
| 302 | } |
| 303 | |
| 304 | void |
| 305 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) |
| 306 | char *raw_buffer; |
| 307 | int *optimized; |
| 308 | CORE_ADDR *addrp; |
| 309 | struct frame_info *frame; |
| 310 | int regnum; |
| 311 | enum lval_type *lval; |
| 312 | { |
| 313 | /* printf("get_saved_register\n"); */ |
| 314 | |
| 315 | generic_get_saved_register (raw_buffer, optimized, addrp, |
| 316 | frame, regnum, lval); |
| 317 | } |
| 318 | |
| 319 | /* Function: init_extra_frame_info |
| 320 | Setup the frame's frame pointer, pc, and frame addresses for saved |
| 321 | registers. Most of the work is done in frame_chain(). |
| 322 | |
| 323 | Note that when we are called for the last frame (currently active frame), |
| 324 | that fi->pc and fi->frame will already be setup. However, fi->frame will |
| 325 | be valid only if this routine uses FP. For previous frames, fi-frame will |
| 326 | always be correct (since that is derived from v850_frame_chain ()). |
| 327 | |
| 328 | We can be called with the PC in the call dummy under two circumstances. |
| 329 | First, during normal backtracing, second, while figuring out the frame |
| 330 | pointer just prior to calling the target function (see run_stack_dummy). |
| 331 | */ |
| 332 | |
| 333 | void |
| 334 | mn10300_init_extra_frame_info (fi) |
| 335 | struct frame_info *fi; |
| 336 | { |
| 337 | struct prologue_info pi; |
| 338 | struct pifsr pifsrs[NUM_REGS + 1], *pifsr; |
| 339 | int reg; |
| 340 | |
| 341 | if (fi->next) |
| 342 | fi->pc = FRAME_SAVED_PC (fi->next); |
| 343 | |
| 344 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); |
| 345 | |
| 346 | /* The call dummy doesn't save any registers on the stack, so we can return |
| 347 | now. */ |
| 348 | /* |
| 349 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
| 350 | return; |
| 351 | |
| 352 | pi.pifsrs = pifsrs; |
| 353 | */ |
| 354 | |
| 355 | /* v850_scan_prologue (fi->pc, &pi); */ |
| 356 | /* |
| 357 | if (!fi->next && pi.framereg == SP_REGNUM) |
| 358 | fi->frame = read_register (pi.framereg) - pi.frameoffset; |
| 359 | |
| 360 | for (pifsr = pifsrs; pifsr->framereg; pifsr++) |
| 361 | { |
| 362 | fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame; |
| 363 | |
| 364 | if (pifsr->framereg == SP_REGNUM) |
| 365 | fi->fsr.regs[pifsr->reg] += pi.frameoffset; |
| 366 | } |
| 367 | */ |
| 368 | /* printf("init_extra_frame_info\n"); */ |
| 369 | } |
| 370 | |
| 371 | void |
| 372 | _initialize_mn10300_tdep () |
| 373 | { |
| 374 | /* printf("_initialize_mn10300_tdep\n"); */ |
| 375 | |
| 376 | tm_print_insn = print_insn_mn10300; |
| 377 | } |
| 378 | |