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 29 #include <sys/param.h> /* to pick up __FreeBSD_version */ 30 #include <string.h> 31 #include <stand.h> 32 #include "bootstrap.h" 33 #include "ficl.h" 34 35 extern unsigned bootprog_rev; 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 30000 58 #endif 59 60 /* 61 * BootForth Interface to Ficl Forth interpreter. 62 */ 63 64 ficlSystemInformation *fsi; 65 ficlSystem *bf_sys; 66 ficlVm *bf_vm; 67 68 /* 69 * Shim for taking commands from BF and passing them out to 'standard' 70 * argv/argc command functions. 71 */ 72 static void 73 bf_command(ficlVm *vm) 74 { 75 char *name, *line, *tail, *cp; 76 size_t len; 77 struct bootblk_command **cmdp; 78 bootblk_cmd_t *cmd; 79 int nstrings, i; 80 int argc, result; 81 char **argv; 82 83 /* Get the name of the current word */ 84 name = vm->runningWord->name; 85 86 /* Find our command structure */ 87 cmd = NULL; 88 SET_FOREACH(cmdp, Xcommand_set) { 89 if (((*cmdp)->c_name != NULL) && 90 strcmp(name, (*cmdp)->c_name) == 0) 91 cmd = (*cmdp)->c_fn; 92 } 93 if (cmd == NULL) 94 panic("callout for unknown command '%s'", name); 95 96 /* Check whether we have been compiled or are being interpreted */ 97 if (ficlStackPopInteger(ficlVmGetDataStack(vm))) { 98 /* 99 * Get parameters from stack, in the format: 100 * an un ... a2 u2 a1 u1 n -- 101 * Where n is the number of strings, a/u are pairs of 102 * address/size for strings, and they will be concatenated 103 * in LIFO order. 104 */ 105 nstrings = ficlStackPopInteger(ficlVmGetDataStack(vm)); 106 for (i = 0, len = 0; i < nstrings; i++) { 107 ficlStack *stack = ficlVmGetDataStack(vm); 108 len += ficlStackFetch(stack, i * 2).i + 1; 109 } 110 line = malloc(strlen(name) + len + 1); 111 (void) strcpy(line, name); 112 113 if (nstrings) 114 for (i = 0; i < nstrings; i++) { 115 ficlStack *stack = ficlVmGetDataStack(vm); 116 117 len = ficlStackPopInteger(stack); 118 cp = ficlStackPopPointer(stack); 119 (void) strcat(line, " "); 120 (void) strncat(line, cp, len); 121 } 122 } else { 123 /* Get remainder of invocation */ 124 tail = ficlVmGetInBuf(vm); 125 126 len = 0; 127 cp = tail; 128 for (; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++) 129 len++; 130 131 line = malloc(strlen(name) + len + 2); 132 (void) strcpy(line, name); 133 if (len > 0) { 134 (void) strcat(line, " "); 135 (void) strncat(line, tail, len); 136 ficlVmUpdateTib(vm, tail + len); 137 } 138 } 139 DPRINTF("cmd '%s'", line); 140 141 command_errmsg = command_errbuf; 142 command_errbuf[0] = 0; 143 if (!parse(&argc, &argv, line)) { 144 result = (cmd)(argc, argv); 145 free(argv); 146 } else { 147 result = BF_PARSE; 148 } 149 150 switch (result) { 151 case CMD_CRIT: 152 printf("%s\n", command_errmsg); 153 command_errmsg = NULL; 154 break; 155 case CMD_FATAL: 156 panic("%s", command_errmsg); 157 } 158 159 free(line); 160 /* 161 * If there was error during nested ficlExec(), we may no longer have 162 * valid environment to return. Throw all exceptions from here. 163 */ 164 if (result != CMD_OK) 165 ficlVmThrow(vm, result); 166 167 /* This is going to be thrown!!! */ 168 ficlStackPushInteger(ficlVmGetDataStack(vm), result); 169 } 170 171 /* 172 * Replace a word definition (a builtin command) with another 173 * one that: 174 * 175 * - Throw error results instead of returning them on the stack 176 * - Pass a flag indicating whether the word was compiled or is 177 * being interpreted. 178 * 179 * There is one major problem with builtins that cannot be overcome 180 * in anyway, except by outlawing it. We want builtins to behave 181 * differently depending on whether they have been compiled or they 182 * are being interpreted. Notice that this is *not* the interpreter's 183 * current state. For example: 184 * 185 * : example ls ; immediate 186 * : problem example ; \ "ls" gets executed while compiling 187 * example \ "ls" gets executed while interpreting 188 * 189 * Notice that, though the current state is different in the two 190 * invocations of "example", in both cases "ls" has been 191 * *compiled in*, which is what we really want. 192 * 193 * The problem arises when you tick the builtin. For example: 194 * 195 * : example-1 ['] ls postpone literal ; immediate 196 * : example-2 example-1 execute ; immediate 197 * : problem example-2 ; 198 * example-2 199 * 200 * We have no way, when we get EXECUTEd, of knowing what our behavior 201 * should be. Thus, our only alternative is to "outlaw" this. See RFI 202 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related 203 * problem, concerning compile semantics. 204 * 205 * The problem is compounded by the fact that "' builtin CATCH" is valid 206 * and desirable. The only solution is to create an intermediary word. 207 * For example: 208 * 209 * : my-ls ls ; 210 * : example ['] my-ls catch ; 211 * 212 * So, with the below implementation, here is a summary of the behavior 213 * of builtins: 214 * 215 * ls -l \ "interpret" behavior, ie, 216 * \ takes parameters from TIB 217 * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie, 218 * \ takes parameters from the stack 219 * : ex-2 ['] ls catch ; immediate \ undefined behavior 220 * : ex-3 ['] ls catch ; \ undefined behavior 221 * ex-2 ex-3 \ "interpret" behavior, 222 * \ catch works 223 * : ex-4 ex-2 ; \ "compile" behavior, 224 * \ catch does not work 225 * : ex-5 ex-3 ; immediate \ same as ex-2 226 * : ex-6 ex-3 ; \ same as ex-3 227 * : ex-7 ['] ex-1 catch ; \ "compile" behavior, 228 * \ catch works 229 * : ex-8 postpone ls ; immediate \ same as ex-2 230 * : ex-9 postpone ls ; \ same as ex-3 231 * 232 * As the definition below is particularly tricky, and it's side effects 233 * must be well understood by those playing with it, I'll be heavy on 234 * the comments. 235 * 236 * (if you edit this definition, pay attention to trailing spaces after 237 * each word -- I warned you! :-) ) 238 */ 239 #define BUILTIN_CONSTRUCTOR \ 240 ": builtin: " \ 241 ">in @ " /* save the tib index pointer */ \ 242 "' " /* get next word's xt */ \ 243 "swap >in ! " /* point again to next word */ \ 244 "create " /* create a new definition of the next word */ \ 245 ", " /* save previous definition's xt */ \ 246 "immediate " /* make the new definition an immediate word */ \ 247 \ 248 "does> " /* Now, the *new* definition will: */ \ 249 "state @ if " /* if in compiling state: */ \ 250 "1 postpone literal " /* pass 1 flag to indicate compile */ \ 251 "@ compile, " /* compile in previous definition */ \ 252 "postpone throw " /* throw stack-returned result */ \ 253 "else " /* if in interpreting state: */ \ 254 "0 swap " /* pass 0 flag to indicate interpret */ \ 255 "@ execute " /* call previous definition */ \ 256 "throw " /* throw stack-returned result */ \ 257 "then ; " 258 259 /* 260 * Initialise the Forth interpreter, create all our commands as words. 261 */ 262 void 263 bf_init(char *rc) 264 { 265 struct bootblk_command **cmdp; 266 char create_buf[41]; /* 31 characters-long builtins */ 267 int fd, rv; 268 ficlDictionary *dict; 269 ficlDictionary *env; 270 271 fsi = malloc(sizeof (ficlSystemInformation)); 272 ficlSystemInformationInitialize(fsi); 273 fsi->dictionarySize = BF_DICTSIZE; 274 275 bf_sys = ficlSystemCreate(fsi); 276 bf_vm = ficlSystemCreateVm(bf_sys); 277 278 /* Put all private definitions in a "builtins" vocabulary */ 279 rv = ficlVmEvaluate(bf_vm, 280 "vocabulary builtins also builtins definitions"); 281 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 282 panic("error interpreting forth: %d", rv); 283 } 284 285 /* Builtin constructor word */ 286 rv = ficlVmEvaluate(bf_vm, BUILTIN_CONSTRUCTOR); 287 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 288 panic("error interpreting forth: %d", rv); 289 } 290 291 /* make all commands appear as Forth words */ 292 dict = ficlSystemGetDictionary(bf_sys); 293 SET_FOREACH(cmdp, Xcommand_set) { 294 (void) ficlDictionaryAppendPrimitive(dict, 295 (char *)(*cmdp)->c_name, bf_command, FICL_WORD_DEFAULT); 296 rv = ficlVmEvaluate(bf_vm, "forth definitions builtins"); 297 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 298 panic("error interpreting forth: %d", rv); 299 } 300 (void) snprintf(create_buf, sizeof (create_buf), 301 "builtin: %s", (*cmdp)->c_name); 302 rv = ficlVmEvaluate(bf_vm, create_buf); 303 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 304 panic("error interpreting forth: %d", rv); 305 } 306 rv = ficlVmEvaluate(bf_vm, "builtins definitions"); 307 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 308 panic("error interpreting forth: %d", rv); 309 } 310 } 311 rv = ficlVmEvaluate(bf_vm, "only forth definitions"); 312 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 313 panic("error interpreting forth: %d", rv); 314 } 315 316 /* 317 * Export some version numbers so that code can detect the loader/host 318 * version 319 */ 320 env = ficlSystemGetEnvironment(bf_sys); 321 (void) ficlDictionarySetConstant(env, "loader_version", bootprog_rev); 322 323 /* try to load and run init file if present */ 324 if (rc == NULL) 325 rc = "/boot/forth/boot.4th"; 326 if (*rc != '\0') { 327 fd = open(rc, O_RDONLY); 328 if (fd != -1) { 329 (void) ficlExecFD(bf_vm, fd); 330 (void) close(fd); 331 } 332 } 333 } 334 335 /* 336 * Feed a line of user input to the Forth interpreter 337 */ 338 int 339 bf_run(char *line) 340 { 341 int result; 342 ficlString s; 343 344 FICL_STRING_SET_FROM_CSTRING(s, line); 345 result = ficlVmExecuteString(bf_vm, s); 346 347 DPRINTF("ficlExec '%s' = %d", line, result); 348 switch (result) { 349 case FICL_VM_STATUS_OUT_OF_TEXT: 350 case FICL_VM_STATUS_ABORTQ: 351 case FICL_VM_STATUS_QUIT: 352 case FICL_VM_STATUS_ERROR_EXIT: 353 break; 354 case FICL_VM_STATUS_USER_EXIT: 355 printf("No where to leave to!\n"); 356 break; 357 case FICL_VM_STATUS_ABORT: 358 printf("Aborted!\n"); 359 break; 360 case BF_PARSE: 361 printf("Parse error!\n"); 362 break; 363 default: 364 if (command_errmsg != NULL) { 365 printf("%s\n", command_errmsg); 366 command_errmsg = NULL; 367 } 368 } 369 370 /* bye is same as reboot and will behave depending on platform */ 371 if (result == FICL_VM_STATUS_USER_EXIT) 372 (void) bf_run("reboot"); 373 (void) setenv("interpret", bf_vm->state ? "" : "ok", 1); 374 375 return (result); 376 } 377