1 /*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/param.h> /* to pick up __FreeBSD_version */ 28 #include <string.h> 29 #include <stand.h> 30 #include "bootstrap.h" 31 #include "ficl.h" 32 33 INTERP_DEFINE("4th"); 34 35 /* #define BFORTH_DEBUG */ 36 37 #ifdef BFORTH_DEBUG 38 #define DPRINTF(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 39 #else 40 #define DPRINTF(fmt, args...) ((void)0) 41 #endif 42 43 /* 44 * Eventually, all builtin commands throw codes must be defined 45 * elsewhere, possibly bootstrap.h. For now, just this code, used 46 * just in this file, it is getting defined. 47 */ 48 #define BF_PARSE 100 49 50 /* 51 * FreeBSD loader default dictionary cells 52 */ 53 #ifndef BF_DICTSIZE 54 #define BF_DICTSIZE 10000 55 #endif 56 57 /* 58 * BootForth Interface to Ficl Forth interpreter. 59 */ 60 61 FICL_SYSTEM *bf_sys; 62 FICL_VM *bf_vm; 63 64 /* 65 * Shim for taking commands from BF and passing them out to 'standard' 66 * argv/argc command functions. 67 */ 68 static void 69 bf_command(FICL_VM *vm) 70 { 71 char *name, *line, *tail, *cp; 72 size_t len; 73 struct bootblk_command **cmdp; 74 bootblk_cmd_t *cmd; 75 int nstrings, i; 76 int argc, result; 77 char **argv; 78 79 /* Get the name of the current word */ 80 name = vm->runningWord->name; 81 82 /* Find our command structure */ 83 cmd = NULL; 84 SET_FOREACH(cmdp, Xcommand_set) { 85 if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name)) 86 cmd = (*cmdp)->c_fn; 87 } 88 if (cmd == NULL) 89 panic("callout for unknown command '%s'", name); 90 91 /* Check whether we have been compiled or are being interpreted */ 92 if (stackPopINT(vm->pStack)) { 93 /* 94 * Get parameters from stack, in the format: 95 * an un ... a2 u2 a1 u1 n -- 96 * Where n is the number of strings, a/u are pairs of 97 * address/size for strings, and they will be concatenated 98 * in LIFO order. 99 */ 100 nstrings = stackPopINT(vm->pStack); 101 for (i = 0, len = 0; i < nstrings; i++) 102 len += stackFetch(vm->pStack, i * 2).i + 1; 103 line = malloc(strlen(name) + len + 1); 104 strcpy(line, name); 105 106 if (nstrings) 107 for (i = 0; i < nstrings; i++) { 108 len = stackPopINT(vm->pStack); 109 cp = stackPopPtr(vm->pStack); 110 strcat(line, " "); 111 strncat(line, cp, len); 112 } 113 } else { 114 /* Get remainder of invocation */ 115 tail = vmGetInBuf(vm); 116 for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++) 117 ; 118 119 line = malloc(strlen(name) + len + 2); 120 strcpy(line, name); 121 if (len > 0) { 122 strcat(line, " "); 123 strncat(line, tail, len); 124 vmUpdateTib(vm, tail + len); 125 } 126 } 127 DPRINTF("cmd '%s'", line); 128 129 command_errmsg = command_errbuf; 130 command_errbuf[0] = 0; 131 if (!parse(&argc, &argv, line)) { 132 result = (cmd)(argc, argv); 133 free(argv); 134 } else { 135 result=BF_PARSE; 136 } 137 138 switch (result) { 139 case CMD_CRIT: 140 printf("%s\n", command_errmsg); 141 command_errmsg = NULL; 142 break; 143 case CMD_FATAL: 144 panic("%s", command_errmsg); 145 } 146 147 free(line); 148 /* 149 * If there was error during nested ficlExec(), we may no longer have 150 * valid environment to return. Throw all exceptions from here. 151 */ 152 if (result != CMD_OK) 153 vmThrow(vm, result); 154 155 /* This is going to be thrown!!! */ 156 stackPushINT(vm->pStack,result); 157 } 158 159 /* 160 * Replace a word definition (a builtin command) with another 161 * one that: 162 * 163 * - Throw error results instead of returning them on the stack 164 * - Pass a flag indicating whether the word was compiled or is 165 * being interpreted. 166 * 167 * There is one major problem with builtins that cannot be overcome 168 * in anyway, except by outlawing it. We want builtins to behave 169 * differently depending on whether they have been compiled or they 170 * are being interpreted. Notice that this is *not* the interpreter's 171 * current state. For example: 172 * 173 * : example ls ; immediate 174 * : problem example ; \ "ls" gets executed while compiling 175 * example \ "ls" gets executed while interpreting 176 * 177 * Notice that, though the current state is different in the two 178 * invocations of "example", in both cases "ls" has been 179 * *compiled in*, which is what we really want. 180 * 181 * The problem arises when you tick the builtin. For example: 182 * 183 * : example-1 ['] ls postpone literal ; immediate 184 * : example-2 example-1 execute ; immediate 185 * : problem example-2 ; 186 * example-2 187 * 188 * We have no way, when we get EXECUTEd, of knowing what our behavior 189 * should be. Thus, our only alternative is to "outlaw" this. See RFI 190 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related 191 * problem, concerning compile semantics. 192 * 193 * The problem is compounded by the fact that "' builtin CATCH" is valid 194 * and desirable. The only solution is to create an intermediary word. 195 * For example: 196 * 197 * : my-ls ls ; 198 * : example ['] my-ls catch ; 199 * 200 * So, with the below implementation, here is a summary of the behavior 201 * of builtins: 202 * 203 * ls -l \ "interpret" behavior, ie, 204 * \ takes parameters from TIB 205 * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie, 206 * \ takes parameters from the stack 207 * : ex-2 ['] ls catch ; immediate \ undefined behavior 208 * : ex-3 ['] ls catch ; \ undefined behavior 209 * ex-2 ex-3 \ "interpret" behavior, 210 * \ catch works 211 * : ex-4 ex-2 ; \ "compile" behavior, 212 * \ catch does not work 213 * : ex-5 ex-3 ; immediate \ same as ex-2 214 * : ex-6 ex-3 ; \ same as ex-3 215 * : ex-7 ['] ex-1 catch ; \ "compile" behavior, 216 * \ catch works 217 * : ex-8 postpone ls ; immediate \ same as ex-2 218 * : ex-9 postpone ls ; \ same as ex-3 219 * 220 * As the definition below is particularly tricky, and it's side effects 221 * must be well understood by those playing with it, I'll be heavy on 222 * the comments. 223 * 224 * (if you edit this definition, pay attention to trailing spaces after 225 * each word -- I warned you! :-) ) 226 */ 227 #define BUILTIN_CONSTRUCTOR \ 228 ": builtin: " \ 229 ">in @ " /* save the tib index pointer */ \ 230 "' " /* get next word's xt */ \ 231 "swap >in ! " /* point again to next word */ \ 232 "create " /* create a new definition of the next word */ \ 233 ", " /* save previous definition's xt */ \ 234 "immediate " /* make the new definition an immediate word */ \ 235 \ 236 "does> " /* Now, the *new* definition will: */ \ 237 "state @ if " /* if in compiling state: */ \ 238 "1 postpone literal " /* pass 1 flag to indicate compile */ \ 239 "@ compile, " /* compile in previous definition */ \ 240 "postpone throw " /* throw stack-returned result */ \ 241 "else " /* if in interpreting state: */ \ 242 "0 swap " /* pass 0 flag to indicate interpret */ \ 243 "@ execute " /* call previous definition */ \ 244 "throw " /* throw stack-returned result */ \ 245 "then ; " 246 247 /* 248 * Initialise the Forth interpreter, create all our commands as words. 249 */ 250 void 251 bf_init(void) 252 { 253 struct bootblk_command **cmdp; 254 char create_buf[41]; /* 31 characters-long builtins */ 255 int fd; 256 257 bf_sys = ficlInitSystem(BF_DICTSIZE); 258 bf_vm = ficlNewVM(bf_sys); 259 260 /* Put all private definitions in a "builtins" vocabulary */ 261 ficlExec(bf_vm, "vocabulary builtins also builtins definitions"); 262 263 /* Builtin constructor word */ 264 ficlExec(bf_vm, BUILTIN_CONSTRUCTOR); 265 266 /* make all commands appear as Forth words */ 267 SET_FOREACH(cmdp, Xcommand_set) { 268 ficlBuild(bf_sys, (char *)(*cmdp)->c_name, bf_command, FW_DEFAULT); 269 ficlExec(bf_vm, "forth definitions builtins"); 270 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); 271 ficlExec(bf_vm, create_buf); 272 ficlExec(bf_vm, "builtins definitions"); 273 } 274 ficlExec(bf_vm, "only forth definitions"); 275 276 /* Export some version numbers so that code can detect the loader/host version */ 277 ficlSetEnv(bf_sys, "FreeBSD_version", __FreeBSD_version); 278 ficlSetEnv(bf_sys, "loader_version", bootprog_rev); 279 280 /* try to load and run init file if present */ 281 if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) { 282 #ifdef LOADER_VERIEXEC 283 if (verify_file(fd, "/boot/boot.4th", 0, VE_GUESS, __func__) < 0) { 284 close(fd); 285 return; 286 } 287 #endif 288 (void)ficlExecFD(bf_vm, fd); 289 close(fd); 290 } 291 } 292 293 /* 294 * Feed a line of user input to the Forth interpreter 295 */ 296 static int 297 bf_run(const char *line) 298 { 299 int result; 300 301 /* 302 * ficl would require extensive changes to accept a const char * 303 * interface. Instead, cast it away here and hope for the best. 304 * We know at the present time the caller for us in the boot 305 * forth loader can tolerate the string being modified because 306 * the string is passed in here and then not touched again. 307 */ 308 result = ficlExec(bf_vm, __DECONST(char *, line)); 309 310 DPRINTF("ficlExec '%s' = %d", line, result); 311 switch (result) { 312 case VM_OUTOFTEXT: 313 case VM_ABORTQ: 314 case VM_QUIT: 315 case VM_ERREXIT: 316 break; 317 case VM_USEREXIT: 318 printf("No where to leave to!\n"); 319 break; 320 case VM_ABORT: 321 printf("Aborted!\n"); 322 break; 323 case BF_PARSE: 324 printf("Parse error!\n"); 325 break; 326 default: 327 if (command_errmsg != NULL) { 328 printf("%s\n", command_errmsg); 329 command_errmsg = NULL; 330 } 331 } 332 333 if (result == VM_USEREXIT) 334 panic("interpreter exit"); 335 setenv("interpret", bf_vm->state ? "" : "OK", 1); 336 337 return (result); 338 } 339 340 void 341 interp_init(void) 342 { 343 344 setenv("script.lang", "forth", 1); 345 bf_init(); 346 /* Read our default configuration. */ 347 interp_include("/boot/loader.rc"); 348 } 349 350 int 351 interp_run(const char *input) 352 { 353 354 bf_vm->sourceID.i = 0; 355 return bf_run(input); 356 } 357 358 /* 359 * Header prepended to each line. The text immediately follows the header. 360 * We try to make this short in order to save memory -- the loader has 361 * limited memory available, and some of the forth files are very long. 362 */ 363 struct includeline 364 { 365 struct includeline *next; 366 char text[0]; 367 }; 368 369 int 370 interp_include(const char *filename) 371 { 372 struct includeline *script, *se, *sp; 373 char input[256]; /* big enough? */ 374 int res; 375 char *cp; 376 int prevsrcid, fd, line; 377 378 if (((fd = open(filename, O_RDONLY)) == -1)) { 379 snprintf(command_errbuf, sizeof(command_errbuf), 380 "can't open '%s': %s", filename, strerror(errno)); 381 return(CMD_ERROR); 382 } 383 384 #ifdef LOADER_VERIEXEC 385 if (verify_file(fd, filename, 0, VE_GUESS, __func__) < 0) { 386 close(fd); 387 sprintf(command_errbuf,"can't verify '%s'", filename); 388 return(CMD_ERROR); 389 } 390 #endif 391 /* 392 * Read the script into memory. 393 */ 394 script = se = NULL; 395 line = 0; 396 397 while (fgetstr(input, sizeof(input), fd) >= 0) { 398 line++; 399 cp = input; 400 /* Allocate script line structure and copy line, flags */ 401 if (*cp == '\0') 402 continue; /* ignore empty line, save memory */ 403 sp = malloc(sizeof(struct includeline) + strlen(cp) + 1); 404 /* On malloc failure (it happens!), free as much as possible and exit */ 405 if (sp == NULL) { 406 while (script != NULL) { 407 se = script; 408 script = script->next; 409 free(se); 410 } 411 snprintf(command_errbuf, sizeof(command_errbuf), 412 "file '%s' line %d: memory allocation failure - aborting", 413 filename, line); 414 close(fd); 415 return (CMD_ERROR); 416 } 417 strcpy(sp->text, cp); 418 sp->next = NULL; 419 420 if (script == NULL) { 421 script = sp; 422 } else { 423 se->next = sp; 424 } 425 se = sp; 426 } 427 close(fd); 428 429 /* 430 * Execute the script 431 */ 432 prevsrcid = bf_vm->sourceID.i; 433 bf_vm->sourceID.i = fd; 434 res = CMD_OK; 435 for (sp = script; sp != NULL; sp = sp->next) { 436 res = bf_run(sp->text); 437 if (res != VM_OUTOFTEXT) { 438 snprintf(command_errbuf, sizeof(command_errbuf), 439 "Error while including %s, in the line:\n%s", 440 filename, sp->text); 441 res = CMD_ERROR; 442 break; 443 } else 444 res = CMD_OK; 445 } 446 bf_vm->sourceID.i = prevsrcid; 447 448 while (script != NULL) { 449 se = script; 450 script = script->next; 451 free(se); 452 } 453 return(res); 454 } 455