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 DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 41 #else 42 # define DEBUG(fmt, args...) 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) && !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 (ficlStackPopInteger(ficlVmGetDataStack(vm))) { 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 = ficlStackPopInteger(ficlVmGetDataStack(vm)); 104 for (i = 0, len = 0; i < nstrings; i++) 105 len += ficlStackFetch(ficlVmGetDataStack(vm), 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 = ficlStackPopInteger(ficlVmGetDataStack(vm)); 112 cp = ficlStackPopPointer(ficlVmGetDataStack(vm)); 113 strcat(line, " "); 114 strncat(line, cp, len); 115 } 116 } else { 117 /* Get remainder of invocation */ 118 tail = ficlVmGetInBuf(vm); 119 120 for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++) 121 ; 122 123 line = malloc(strlen(name) + len + 2); 124 strcpy(line, name); 125 if (len > 0) { 126 strcat(line, " "); 127 strncat(line, tail, len); 128 ficlVmUpdateTib(vm, tail + len); 129 } 130 } 131 DEBUG("cmd '%s'", line); 132 133 command_errmsg = command_errbuf; 134 command_errbuf[0] = 0; 135 if (!parse(&argc, &argv, line)) { 136 result = (cmd)(argc, argv); 137 free(argv); 138 } else { 139 result=BF_PARSE; 140 } 141 142 switch (result) { 143 case CMD_CRIT: 144 printf("%s\n", command_errmsg); 145 break; 146 case CMD_FATAL: 147 panic("%s\n", 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 ficlVmThrow(vm, result); 157 158 /* This is going to be thrown!!! */ 159 ficlStackPushInteger(ficlVmGetDataStack(vm),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(char *rc) 255 { 256 struct bootblk_command **cmdp; 257 char create_buf[41]; /* 31 characters-long builtins */ 258 int fd, rv; 259 ficlDictionary *dict; 260 ficlDictionary *env; 261 262 fsi = malloc(sizeof(ficlSystemInformation)); 263 ficlSystemInformationInitialize(fsi); 264 fsi->dictionarySize = BF_DICTSIZE; 265 266 bf_sys = ficlSystemCreate(fsi); 267 bf_vm = ficlSystemCreateVm(bf_sys); 268 269 /* Put all private definitions in a "builtins" vocabulary */ 270 rv = ficlVmEvaluate(bf_vm, "vocabulary builtins also builtins definitions"); 271 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 272 panic("error interpreting forth: %d\n", rv); 273 } 274 275 /* Builtin constructor word */ 276 rv = ficlVmEvaluate(bf_vm, BUILTIN_CONSTRUCTOR); 277 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 278 panic("error interpreting forth: %d\n", rv); 279 } 280 281 /* make all commands appear as Forth words */ 282 dict = ficlSystemGetDictionary(bf_sys); 283 SET_FOREACH(cmdp, Xcommand_set) { 284 ficlDictionaryAppendPrimitive(dict, (char *)(*cmdp)->c_name, 285 bf_command, FICL_WORD_DEFAULT); 286 rv = ficlVmEvaluate(bf_vm, "forth definitions builtins"); 287 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 288 panic("error interpreting forth: %d\n", rv); 289 } 290 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); 291 rv = ficlVmEvaluate(bf_vm, create_buf); 292 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 293 panic("error interpreting forth: %d\n", rv); 294 } 295 rv = ficlVmEvaluate(bf_vm, "builtins definitions"); 296 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 297 panic("error interpreting forth: %d\n", rv); 298 } 299 } 300 rv = ficlVmEvaluate(bf_vm, "only forth definitions"); 301 if (rv != FICL_VM_STATUS_OUT_OF_TEXT) { 302 panic("error interpreting forth: %d\n", rv); 303 } 304 305 /* 306 * Export some version numbers so that code can detect the loader/host 307 * version 308 */ 309 env = ficlSystemGetEnvironment(bf_sys); 310 ficlDictionarySetConstant(env, "loader_version", bootprog_rev); 311 312 /* try to load and run init file if present */ 313 if (rc == NULL) 314 rc = "/boot/forth/boot.4th"; 315 if (*rc != '\0') { 316 fd = open(rc, O_RDONLY); 317 if (fd != -1) { 318 (void)ficlExecFD(bf_vm, fd); 319 close(fd); 320 } 321 } 322 } 323 324 /* 325 * Feed a line of user input to the Forth interpreter 326 */ 327 int 328 bf_run(char *line) 329 { 330 int result; 331 ficlString s; 332 333 FICL_STRING_SET_FROM_CSTRING(s, line); 334 result = ficlVmExecuteString(bf_vm, s); 335 336 DEBUG("ficlExec '%s' = %d", line, result); 337 switch (result) { 338 case FICL_VM_STATUS_OUT_OF_TEXT: 339 case FICL_VM_STATUS_ABORTQ: 340 case FICL_VM_STATUS_QUIT: 341 case FICL_VM_STATUS_ERROR_EXIT: 342 break; 343 case FICL_VM_STATUS_USER_EXIT: 344 printf("No where to leave to!\n"); 345 break; 346 case FICL_VM_STATUS_ABORT: 347 printf("Aborted!\n"); 348 break; 349 case BF_PARSE: 350 printf("Parse error!\n"); 351 break; 352 default: 353 if (command_errmsg != NULL) { 354 printf("%s\n", command_errmsg); 355 command_errmsg = NULL; 356 } 357 } 358 359 /* bye is same as reboot and will behave depending on platform */ 360 if (result == FICL_VM_STATUS_USER_EXIT) 361 bf_run("reboot"); 362 setenv("interpret", bf_vm->state ? "" : "ok", 1); 363 364 return (result); 365 } 366