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 37 /* #define BFORTH_DEBUG */ 38 39 #ifdef BFORTH_DEBUG 40 #define DPRINTF(fmt, args...) printf("%s: " fmt "\n", __func__, ## args) 41 #else 42 #define DPRINTF(fmt, args...) ((void)0) 43 #endif 44 45 /* 46 * Eventually, all builtin commands throw codes must be defined 47 * elsewhere, possibly bootstrap.h. For now, just this code, used 48 * just in this file, it is getting defined. 49 */ 50 #define BF_PARSE 100 51 52 /* 53 * FreeBSD loader default dictionary cells 54 */ 55 #ifndef BF_DICTSIZE 56 #define BF_DICTSIZE 30000 57 #endif 58 59 /* 60 * BootForth Interface to Ficl Forth interpreter. 61 */ 62 63 ficlSystemInformation *fsi; 64 ficlSystem *bf_sys; 65 ficlVm *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(ficlVm *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) && 89 strcmp(name, (*cmdp)->c_name) == 0) 90 cmd = (*cmdp)->c_fn; 91 } 92 if (cmd == NULL) 93 panic("callout for unknown command '%s'", name); 94 95 /* Check whether we have been compiled or are being interpreted */ 96 if (ficlStackPopInteger(ficlVmGetDataStack(vm))) { 97 /* 98 * Get parameters from stack, in the format: 99 * an un ... a2 u2 a1 u1 n -- 100 * Where n is the number of strings, a/u are pairs of 101 * address/size for strings, and they will be concatenated 102 * in LIFO order. 103 */ 104 nstrings = ficlStackPopInteger(ficlVmGetDataStack(vm)); 105 for (i = 0, len = 0; i < nstrings; i++) { 106 ficlStack *stack = ficlVmGetDataStack(vm); 107 len += ficlStackFetch(stack, i * 2).i + 1; 108 } 109 line = malloc(strlen(name) + len + 1); 110 strcpy(line, name); 111 112 if (nstrings) 113 for (i = 0; i < nstrings; i++) { 114 ficlStack *stack = ficlVmGetDataStack(vm); 115 116 len = ficlStackPopInteger(stack); 117 cp = ficlStackPopPointer(stack); 118 strcat(line, " "); 119 strncat(line, cp, len); 120 } 121 } else { 122 /* Get remainder of invocation */ 123 tail = ficlVmGetInBuf(vm); 124 125 len = 0; 126 cp = tail; 127 for (; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++) 128 len++; 129 130 line = malloc(strlen(name) + len + 2); 131 strcpy(line, name); 132 if (len > 0) { 133 strcat(line, " "); 134 strncat(line, tail, len); 135 ficlVmUpdateTib(vm, tail + len); 136 } 137 } 138 DPRINTF("cmd '%s'", line); 139 140 command_errmsg = command_errbuf; 141 command_errbuf[0] = 0; 142 if (!parse(&argc, &argv, line)) { 143 result = (cmd)(argc, argv); 144 free(argv); 145 } else { 146 result = BF_PARSE; 147 } 148 149 switch (result) { 150 case CMD_CRIT: 151 printf("%s\n", command_errmsg); 152 command_errmsg = NULL; 153 break; 154 case CMD_FATAL: 155 panic("%s", command_errmsg); 156 } 157 158 free(line); 159 /* 160 * If there was error during nested ficlExec(), we may no longer have 161 * valid environment to return. Throw all exceptions from here. 162 */ 163 if (result != CMD_OK) 164 ficlVmThrow(vm, result); 165 166 /* This is going to be thrown!!! */ 167 ficlStackPushInteger(ficlVmGetDataStack(vm), result); 168 } 169 170 /* 171 * Replace a word definition (a builtin command) with another 172 * one that: 173 * 174 * - Throw error results instead of returning them on the stack 175 * - Pass a flag indicating whether the word was compiled or is 176 * being interpreted. 177 * 178 * There is one major problem with builtins that cannot be overcome 179 * in anyway, except by outlawing it. We want builtins to behave 180 * differently depending on whether they have been compiled or they 181 * are being interpreted. Notice that this is *not* the interpreter's 182 * current state. For example: 183 * 184 * : example ls ; immediate 185 * : problem example ; \ "ls" gets executed while compiling 186 * example \ "ls" gets executed while interpreting 187 * 188 * Notice that, though the current state is different in the two 189 * invocations of "example", in both cases "ls" has been 190 * *compiled in*, which is what we really want. 191 * 192 * The problem arises when you tick the builtin. For example: 193 * 194 * : example-1 ['] ls postpone literal ; immediate 195 * : example-2 example-1 execute ; immediate 196 * : problem example-2 ; 197 * example-2 198 * 199 * We have no way, when we get EXECUTEd, of knowing what our behavior 200 * should be. Thus, our only alternative is to "outlaw" this. See RFI 201 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related 202 * problem, concerning compile semantics. 203 * 204 * The problem is compounded by the fact that "' builtin CATCH" is valid 205 * and desirable. The only solution is to create an intermediary word. 206 * For example: 207 * 208 * : my-ls ls ; 209 * : example ['] my-ls catch ; 210 * 211 * So, with the below implementation, here is a summary of the behavior 212 * of builtins: 213 * 214 * ls -l \ "interpret" behavior, ie, 215 * \ takes parameters from TIB 216 * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie, 217 * \ takes parameters from the stack 218 * : ex-2 ['] ls catch ; immediate \ undefined behavior 219 * : ex-3 ['] ls catch ; \ undefined behavior 220 * ex-2 ex-3 \ "interpret" behavior, 221 * \ catch works 222 * : ex-4 ex-2 ; \ "compile" behavior, 223 * \ catch does not work 224 * : ex-5 ex-3 ; immediate \ same as ex-2 225 * : ex-6 ex-3 ; \ same as ex-3 226 * : ex-7 ['] ex-1 catch ; \ "compile" behavior, 227 * \ catch works 228 * : ex-8 postpone ls ; immediate \ same as ex-2 229 * : ex-9 postpone ls ; \ same as ex-3 230 * 231 * As the definition below is particularly tricky, and it's side effects 232 * must be well understood by those playing with it, I'll be heavy on 233 * the comments. 234 * 235 * (if you edit this definition, pay attention to trailing spaces after 236 * each word -- I warned you! :-) ) 237 */ 238 #define BUILTIN_CONSTRUCTOR \ 239 ": builtin: " \ 240 ">in @ " /* save the tib index pointer */ \ 241 "' " /* get next word's xt */ \ 242 "swap >in ! " /* point again to next word */ \ 243 "create " /* create a new definition of the next word */ \ 244 ", " /* save previous definition's xt */ \ 245 "immediate " /* make the new definition an immediate word */ \ 246 \ 247 "does> " /* Now, the *new* definition will: */ \ 248 "state @ if " /* if in compiling state: */ \ 249 "1 postpone literal " /* pass 1 flag to indicate compile */ \ 250 "@ compile, " /* compile in previous definition */ \ 251 "postpone throw " /* throw stack-returned result */ \ 252 "else " /* if in interpreting state: */ \ 253 "0 swap " /* pass 0 flag to indicate interpret */ \ 254 "@ execute " /* call previous definition */ \ 255 "throw " /* throw stack-returned result */ \ 256 "then ; " 257 258 /* 259 * Initialise the Forth interpreter, create all our commands as words. 260 */ 261 void 262 bf_init(char *rc) 263 { 264 struct bootblk_command **cmdp; 265 char create_buf[41]; /* 31 characters-long builtins */ 266 int fd, rv; 267 ficlDictionary *dict; 268 ficlDictionary *env; 269 270 fsi = malloc(sizeof (ficlSystemInformation)); 271 ficlSystemInformationInitialize(fsi); 272 fsi->dictionarySize = BF_DICTSIZE; 273 274 bf_sys = ficlSystemCreate(fsi); 275 bf_vm = ficlSystemCreateVm(bf_sys); 276 277 /* Put all private definitions in a "builtins" vocabulary */ 278 rv = ficlVmEvaluate(bf_vm, 279 "vocabulary builtins also builtins definitions"); 280 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 281 panic("error interpreting forth: %d", rv); 282 } 283 284 /* Builtin constructor word */ 285 rv = ficlVmEvaluate(bf_vm, BUILTIN_CONSTRUCTOR); 286 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 287 panic("error interpreting forth: %d", rv); 288 } 289 290 /* make all commands appear as Forth words */ 291 dict = ficlSystemGetDictionary(bf_sys); 292 SET_FOREACH(cmdp, Xcommand_set) { 293 ficlDictionaryAppendPrimitive(dict, (char *)(*cmdp)->c_name, 294 bf_command, FICL_WORD_DEFAULT); 295 rv = ficlVmEvaluate(bf_vm, "forth definitions builtins"); 296 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 297 panic("error interpreting forth: %d", rv); 298 } 299 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); 300 rv = ficlVmEvaluate(bf_vm, create_buf); 301 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 302 panic("error interpreting forth: %d", rv); 303 } 304 rv = ficlVmEvaluate(bf_vm, "builtins definitions"); 305 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 306 panic("error interpreting forth: %d", rv); 307 } 308 } 309 rv = ficlVmEvaluate(bf_vm, "only forth definitions"); 310 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 311 panic("error interpreting forth: %d", rv); 312 } 313 314 /* 315 * Export some version numbers so that code can detect the loader/host 316 * version 317 */ 318 env = ficlSystemGetEnvironment(bf_sys); 319 ficlDictionarySetConstant(env, "loader_version", bootprog_rev); 320 321 /* try to load and run init file if present */ 322 if (rc == NULL) 323 rc = "/boot/forth/boot.4th"; 324 if (*rc != '\0') { 325 fd = open(rc, O_RDONLY); 326 if (fd != -1) { 327 (void) ficlExecFD(bf_vm, fd); 328 close(fd); 329 } 330 } 331 } 332 333 /* 334 * Feed a line of user input to the Forth interpreter 335 */ 336 int 337 bf_run(char *line) 338 { 339 int result; 340 ficlString s; 341 342 FICL_STRING_SET_FROM_CSTRING(s, line); 343 result = ficlVmExecuteString(bf_vm, s); 344 345 DPRINTF("ficlExec '%s' = %d", line, result); 346 switch (result) { 347 case FICL_VM_STATUS_OUT_OF_TEXT: 348 case FICL_VM_STATUS_ABORTQ: 349 case FICL_VM_STATUS_QUIT: 350 case FICL_VM_STATUS_ERROR_EXIT: 351 break; 352 case FICL_VM_STATUS_USER_EXIT: 353 printf("No where to leave to!\n"); 354 break; 355 case FICL_VM_STATUS_ABORT: 356 printf("Aborted!\n"); 357 break; 358 case BF_PARSE: 359 printf("Parse error!\n"); 360 break; 361 default: 362 if (command_errmsg != NULL) { 363 printf("%s\n", command_errmsg); 364 command_errmsg = NULL; 365 } 366 } 367 368 /* bye is same as reboot and will behave depending on platform */ 369 if (result == FICL_VM_STATUS_USER_EXIT) 370 bf_run("reboot"); 371 setenv("interpret", bf_vm->state ? "" : "ok", 1); 372 373 return (result); 374 } 375