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/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> /* to pick up __FreeBSD_version */ 31 #include <string.h> 32 #include <stand.h> 33 #include "bootstrap.h" 34 #include "ficl.h" 35 36 INTERP_DEFINE("4th"); 37 38 /* #define BFORTH_DEBUG */ 39 40 #ifdef BFORTH_DEBUG 41 #define DPRINTF(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 42 #else 43 #define DPRINTF(fmt, args...) ((void)0) 44 #endif 45 46 /* 47 * Eventually, all builtin commands throw codes must be defined 48 * elsewhere, possibly bootstrap.h. For now, just this code, used 49 * just in this file, it is getting defined. 50 */ 51 #define BF_PARSE 100 52 53 /* 54 * FreeBSD loader default dictionary cells 55 */ 56 #ifndef BF_DICTSIZE 57 #define BF_DICTSIZE 10000 58 #endif 59 60 /* 61 * BootForth Interface to Ficl Forth interpreter. 62 */ 63 64 FICL_SYSTEM *bf_sys; 65 FICL_VM *bf_vm; 66 67 /* 68 * Shim for taking commands from BF and passing them out to 'standard' 69 * argv/argc command functions. 70 */ 71 static void 72 bf_command(FICL_VM *vm) 73 { 74 char *name, *line, *tail, *cp; 75 size_t len; 76 struct bootblk_command **cmdp; 77 bootblk_cmd_t *cmd; 78 int nstrings, i; 79 int argc, result; 80 char **argv; 81 82 /* Get the name of the current word */ 83 name = vm->runningWord->name; 84 85 /* Find our command structure */ 86 cmd = NULL; 87 SET_FOREACH(cmdp, Xcommand_set) { 88 if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name)) 89 cmd = (*cmdp)->c_fn; 90 } 91 if (cmd == NULL) 92 panic("callout for unknown command '%s'", name); 93 94 /* Check whether we have been compiled or are being interpreted */ 95 if (stackPopINT(vm->pStack)) { 96 /* 97 * Get parameters from stack, in the format: 98 * an un ... a2 u2 a1 u1 n -- 99 * Where n is the number of strings, a/u are pairs of 100 * address/size for strings, and they will be concatenated 101 * in LIFO order. 102 */ 103 nstrings = stackPopINT(vm->pStack); 104 for (i = 0, len = 0; i < nstrings; i++) 105 len += stackFetch(vm->pStack, i * 2).i + 1; 106 line = malloc(strlen(name) + len + 1); 107 strcpy(line, name); 108 109 if (nstrings) 110 for (i = 0; i < nstrings; i++) { 111 len = stackPopINT(vm->pStack); 112 cp = stackPopPtr(vm->pStack); 113 strcat(line, " "); 114 strncat(line, cp, len); 115 } 116 } else { 117 /* Get remainder of invocation */ 118 tail = vmGetInBuf(vm); 119 for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++) 120 ; 121 122 line = malloc(strlen(name) + len + 2); 123 strcpy(line, name); 124 if (len > 0) { 125 strcat(line, " "); 126 strncat(line, tail, len); 127 vmUpdateTib(vm, tail + len); 128 } 129 } 130 DPRINTF("cmd '%s'", line); 131 132 command_errmsg = command_errbuf; 133 command_errbuf[0] = 0; 134 if (!parse(&argc, &argv, line)) { 135 result = (cmd)(argc, argv); 136 free(argv); 137 } else { 138 result=BF_PARSE; 139 } 140 141 switch (result) { 142 case CMD_CRIT: 143 printf("%s\n", command_errmsg); 144 command_errmsg = NULL; 145 break; 146 case CMD_FATAL: 147 panic("%s", command_errmsg); 148 } 149 150 free(line); 151 /* 152 * If there was error during nested ficlExec(), we may no longer have 153 * valid environment to return. Throw all exceptions from here. 154 */ 155 if (result != CMD_OK) 156 vmThrow(vm, result); 157 158 /* This is going to be thrown!!! */ 159 stackPushINT(vm->pStack,result); 160 } 161 162 /* 163 * Replace a word definition (a builtin command) with another 164 * one that: 165 * 166 * - Throw error results instead of returning them on the stack 167 * - Pass a flag indicating whether the word was compiled or is 168 * being interpreted. 169 * 170 * There is one major problem with builtins that cannot be overcome 171 * in anyway, except by outlawing it. We want builtins to behave 172 * differently depending on whether they have been compiled or they 173 * are being interpreted. Notice that this is *not* the interpreter's 174 * current state. For example: 175 * 176 * : example ls ; immediate 177 * : problem example ; \ "ls" gets executed while compiling 178 * example \ "ls" gets executed while interpreting 179 * 180 * Notice that, though the current state is different in the two 181 * invocations of "example", in both cases "ls" has been 182 * *compiled in*, which is what we really want. 183 * 184 * The problem arises when you tick the builtin. For example: 185 * 186 * : example-1 ['] ls postpone literal ; immediate 187 * : example-2 example-1 execute ; immediate 188 * : problem example-2 ; 189 * example-2 190 * 191 * We have no way, when we get EXECUTEd, of knowing what our behavior 192 * should be. Thus, our only alternative is to "outlaw" this. See RFI 193 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related 194 * problem, concerning compile semantics. 195 * 196 * The problem is compounded by the fact that "' builtin CATCH" is valid 197 * and desirable. The only solution is to create an intermediary word. 198 * For example: 199 * 200 * : my-ls ls ; 201 * : example ['] my-ls catch ; 202 * 203 * So, with the below implementation, here is a summary of the behavior 204 * of builtins: 205 * 206 * ls -l \ "interpret" behavior, ie, 207 * \ takes parameters from TIB 208 * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie, 209 * \ takes parameters from the stack 210 * : ex-2 ['] ls catch ; immediate \ undefined behavior 211 * : ex-3 ['] ls catch ; \ undefined behavior 212 * ex-2 ex-3 \ "interpret" behavior, 213 * \ catch works 214 * : ex-4 ex-2 ; \ "compile" behavior, 215 * \ catch does not work 216 * : ex-5 ex-3 ; immediate \ same as ex-2 217 * : ex-6 ex-3 ; \ same as ex-3 218 * : ex-7 ['] ex-1 catch ; \ "compile" behavior, 219 * \ catch works 220 * : ex-8 postpone ls ; immediate \ same as ex-2 221 * : ex-9 postpone ls ; \ same as ex-3 222 * 223 * As the definition below is particularly tricky, and it's side effects 224 * must be well understood by those playing with it, I'll be heavy on 225 * the comments. 226 * 227 * (if you edit this definition, pay attention to trailing spaces after 228 * each word -- I warned you! :-) ) 229 */ 230 #define BUILTIN_CONSTRUCTOR \ 231 ": builtin: " \ 232 ">in @ " /* save the tib index pointer */ \ 233 "' " /* get next word's xt */ \ 234 "swap >in ! " /* point again to next word */ \ 235 "create " /* create a new definition of the next word */ \ 236 ", " /* save previous definition's xt */ \ 237 "immediate " /* make the new definition an immediate word */ \ 238 \ 239 "does> " /* Now, the *new* definition will: */ \ 240 "state @ if " /* if in compiling state: */ \ 241 "1 postpone literal " /* pass 1 flag to indicate compile */ \ 242 "@ compile, " /* compile in previous definition */ \ 243 "postpone throw " /* throw stack-returned result */ \ 244 "else " /* if in interpreting state: */ \ 245 "0 swap " /* pass 0 flag to indicate interpret */ \ 246 "@ execute " /* call previous definition */ \ 247 "throw " /* throw stack-returned result */ \ 248 "then ; " 249 250 /* 251 * Initialise the Forth interpreter, create all our commands as words. 252 */ 253 void 254 bf_init(void) 255 { 256 struct bootblk_command **cmdp; 257 char create_buf[41]; /* 31 characters-long builtins */ 258 int fd; 259 260 bf_sys = ficlInitSystem(BF_DICTSIZE); 261 bf_vm = ficlNewVM(bf_sys); 262 263 /* Put all private definitions in a "builtins" vocabulary */ 264 ficlExec(bf_vm, "vocabulary builtins also builtins definitions"); 265 266 /* Builtin constructor word */ 267 ficlExec(bf_vm, BUILTIN_CONSTRUCTOR); 268 269 /* make all commands appear as Forth words */ 270 SET_FOREACH(cmdp, Xcommand_set) { 271 ficlBuild(bf_sys, (char *)(*cmdp)->c_name, bf_command, FW_DEFAULT); 272 ficlExec(bf_vm, "forth definitions builtins"); 273 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); 274 ficlExec(bf_vm, create_buf); 275 ficlExec(bf_vm, "builtins definitions"); 276 } 277 ficlExec(bf_vm, "only forth definitions"); 278 279 /* Export some version numbers so that code can detect the loader/host version */ 280 ficlSetEnv(bf_sys, "FreeBSD_version", __FreeBSD_version); 281 ficlSetEnv(bf_sys, "loader_version", bootprog_rev); 282 283 /* try to load and run init file if present */ 284 if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) { 285 #ifdef LOADER_VERIEXEC 286 if (verify_file(fd, "/boot/boot.4th", 0, VE_GUESS, __func__) < 0) { 287 close(fd); 288 return; 289 } 290 #endif 291 (void)ficlExecFD(bf_vm, fd); 292 close(fd); 293 } 294 } 295 296 /* 297 * Feed a line of user input to the Forth interpreter 298 */ 299 static int 300 bf_run(const char *line) 301 { 302 int result; 303 304 /* 305 * ficl would require extensive changes to accept a const char * 306 * interface. Instead, cast it away here and hope for the best. 307 * We know at the present time the caller for us in the boot 308 * forth loader can tolerate the string being modified because 309 * the string is passed in here and then not touched again. 310 */ 311 result = ficlExec(bf_vm, __DECONST(char *, line)); 312 313 DPRINTF("ficlExec '%s' = %d", line, result); 314 switch (result) { 315 case VM_OUTOFTEXT: 316 case VM_ABORTQ: 317 case VM_QUIT: 318 case VM_ERREXIT: 319 break; 320 case VM_USEREXIT: 321 printf("No where to leave to!\n"); 322 break; 323 case VM_ABORT: 324 printf("Aborted!\n"); 325 break; 326 case BF_PARSE: 327 printf("Parse error!\n"); 328 break; 329 default: 330 if (command_errmsg != NULL) { 331 printf("%s\n", command_errmsg); 332 command_errmsg = NULL; 333 } 334 } 335 336 if (result == VM_USEREXIT) 337 panic("interpreter exit"); 338 setenv("interpret", bf_vm->state ? "" : "OK", 1); 339 340 return (result); 341 } 342 343 void 344 interp_init(void) 345 { 346 347 setenv("script.lang", "forth", 1); 348 bf_init(); 349 /* Read our default configuration. */ 350 interp_include("/boot/loader.rc"); 351 } 352 353 int 354 interp_run(const char *input) 355 { 356 357 bf_vm->sourceID.i = 0; 358 return bf_run(input); 359 } 360 361 /* 362 * Header prepended to each line. The text immediately follows the header. 363 * We try to make this short in order to save memory -- the loader has 364 * limited memory available, and some of the forth files are very long. 365 */ 366 struct includeline 367 { 368 struct includeline *next; 369 char text[0]; 370 }; 371 372 int 373 interp_include(const char *filename) 374 { 375 struct includeline *script, *se, *sp; 376 char input[256]; /* big enough? */ 377 int res; 378 char *cp; 379 int prevsrcid, fd, line; 380 381 if (((fd = open(filename, O_RDONLY)) == -1)) { 382 snprintf(command_errbuf, sizeof(command_errbuf), 383 "can't open '%s': %s", filename, strerror(errno)); 384 return(CMD_ERROR); 385 } 386 387 #ifdef LOADER_VERIEXEC 388 if (verify_file(fd, filename, 0, VE_GUESS, __func__) < 0) { 389 close(fd); 390 sprintf(command_errbuf,"can't verify '%s'", filename); 391 return(CMD_ERROR); 392 } 393 #endif 394 /* 395 * Read the script into memory. 396 */ 397 script = se = NULL; 398 line = 0; 399 400 while (fgetstr(input, sizeof(input), fd) >= 0) { 401 line++; 402 cp = input; 403 /* Allocate script line structure and copy line, flags */ 404 if (*cp == '\0') 405 continue; /* ignore empty line, save memory */ 406 sp = malloc(sizeof(struct includeline) + strlen(cp) + 1); 407 /* On malloc failure (it happens!), free as much as possible and exit */ 408 if (sp == NULL) { 409 while (script != NULL) { 410 se = script; 411 script = script->next; 412 free(se); 413 } 414 snprintf(command_errbuf, sizeof(command_errbuf), 415 "file '%s' line %d: memory allocation failure - aborting", 416 filename, line); 417 close(fd); 418 return (CMD_ERROR); 419 } 420 strcpy(sp->text, cp); 421 sp->next = NULL; 422 423 if (script == NULL) { 424 script = sp; 425 } else { 426 se->next = sp; 427 } 428 se = sp; 429 } 430 close(fd); 431 432 /* 433 * Execute the script 434 */ 435 prevsrcid = bf_vm->sourceID.i; 436 bf_vm->sourceID.i = fd; 437 res = CMD_OK; 438 for (sp = script; sp != NULL; sp = sp->next) { 439 res = bf_run(sp->text); 440 if (res != VM_OUTOFTEXT) { 441 snprintf(command_errbuf, sizeof(command_errbuf), 442 "Error while including %s, in the line:\n%s", 443 filename, sp->text); 444 res = CMD_ERROR; 445 break; 446 } else 447 res = CMD_OK; 448 } 449 bf_vm->sourceID.i = prevsrcid; 450 451 while (script != NULL) { 452 se = script; 453 script = script->next; 454 free(se); 455 } 456 return(res); 457 } 458