1 /*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * Copyright (c) 2011 Wojciech A. Koszek <wkoszek@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> /* to pick up __FreeBSD_version */ 32 #include <string.h> 33 #include <stand.h> 34 #include "bootstrap.h" 35 #include "ficl.h" 36 #include "interp.h" 37 38 extern unsigned bootprog_rev; 39 40 /* #define BFORTH_DEBUG */ 41 42 #ifdef BFORTH_DEBUG 43 #define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 44 #else 45 #define DEBUG(fmt, args...) 46 #endif 47 48 /* 49 * Eventually, all builtin commands throw codes must be defined 50 * elsewhere, possibly bootstrap.h. For now, just this code, used 51 * just in this file, it is getting defined. 52 */ 53 #define BF_PARSE 100 54 55 /* 56 * FreeBSD loader default dictionary cells 57 */ 58 #ifndef BF_DICTSIZE 59 #define BF_DICTSIZE 10000 60 #endif 61 62 /* 63 * BootForth Interface to Ficl Forth interpreter. 64 */ 65 struct interp_forth_softc { 66 FICL_SYSTEM *bf_sys; 67 FICL_VM *bf_vm; 68 FICL_WORD *pInterp; 69 }; 70 struct interp_forth_softc forth_softc = { NULL, NULL, NULL }; 71 72 #define RETURN(x) stackPushINT(bf_vm->pStack,!x); return(x) 73 74 /* 75 * Shim for taking commands from BF and passing them out to 'standard' 76 * argv/argc command functions. 77 */ 78 static void 79 bf_command(FICL_VM *vm) 80 { 81 char *name, *line, *tail, *cp; 82 size_t len; 83 struct bootblk_command **cmdp; 84 bootblk_cmd_t *cmd; 85 int nstrings, i; 86 int argc, result; 87 char **argv; 88 89 /* Get the name of the current word */ 90 name = vm->runningWord->name; 91 92 /* Find our command structure */ 93 cmd = NULL; 94 SET_FOREACH(cmdp, Xcommand_set) { 95 if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name)) 96 cmd = (*cmdp)->c_fn; 97 } 98 if (cmd == NULL) 99 panic("callout for unknown command '%s'", name); 100 101 /* Check whether we have been compiled or are being interpreted */ 102 if (stackPopINT(vm->pStack)) { 103 /* 104 * Get parameters from stack, in the format: 105 * an un ... a2 u2 a1 u1 n -- 106 * Where n is the number of strings, a/u are pairs of 107 * address/size for strings, and they will be concatenated 108 * in LIFO order. 109 */ 110 nstrings = stackPopINT(vm->pStack); 111 for (i = 0, len = 0; i < nstrings; i++) 112 len += stackFetch(vm->pStack, i * 2).i + 1; 113 line = malloc(strlen(name) + len + 1); 114 strcpy(line, name); 115 116 if (nstrings) 117 for (i = 0; i < nstrings; i++) { 118 len = stackPopINT(vm->pStack); 119 cp = stackPopPtr(vm->pStack); 120 strcat(line, " "); 121 strncat(line, cp, len); 122 } 123 } else { 124 /* Get remainder of invocation */ 125 tail = vmGetInBuf(vm); 126 for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++) 127 ; 128 129 line = malloc(strlen(name) + len + 2); 130 strcpy(line, name); 131 if (len > 0) { 132 strcat(line, " "); 133 strncat(line, tail, len); 134 vmUpdateTib(vm, tail + len); 135 } 136 } 137 DEBUG("cmd '%s'", line); 138 139 command_errmsg = command_errbuf; 140 command_errbuf[0] = 0; 141 if (!parse(&argc, &argv, line)) { 142 result = (cmd)(argc, argv); 143 free(argv); 144 } else { 145 result=BF_PARSE; 146 } 147 148 /* XXX Not sure about the rest of this -- imp */ 149 150 switch (result) { 151 case CMD_CRIT: 152 printf("%s\n", command_errmsg); 153 break; 154 case CMD_FATAL: 155 panic("%s\n", 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 vmThrow(vm, result); 165 166 /* This is going to be thrown!!! */ 167 stackPushINT(vm->pStack,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 static void 262 interp_forth_init(void *ctx) 263 { 264 struct interp_forth_softc *softc; 265 struct bootblk_command **cmdp; 266 char create_buf[41]; /* 31 characters-long builtins */ 267 FICL_SYSTEM *bf_sys; 268 FICL_VM *bf_vm; 269 270 softc = ctx; 271 272 assert((softc->bf_sys == NULL) && (softc->bf_vm == NULL) && 273 (softc->pInterp == NULL)); /* No Forth context at this stage */ 274 275 bf_sys = softc->bf_sys = ficlInitSystem(BF_DICTSIZE); 276 bf_vm = softc->bf_vm = ficlNewVM(bf_sys); 277 278 /* Put all private definitions in a "builtins" vocabulary */ 279 ficlExec(bf_vm, "vocabulary builtins also builtins definitions"); 280 281 /* Builtin constructor word */ 282 ficlExec(bf_vm, BUILTIN_CONSTRUCTOR); 283 284 /* make all commands appear as Forth words */ 285 SET_FOREACH(cmdp, Xcommand_set) { 286 ficlBuild(bf_sys, (char *)(*cmdp)->c_name, bf_command, FW_DEFAULT); 287 ficlExec(bf_vm, "forth definitions builtins"); 288 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); 289 ficlExec(bf_vm, create_buf); 290 ficlExec(bf_vm, "builtins definitions"); 291 } 292 ficlExec(bf_vm, "only forth definitions"); 293 294 /* Export some version numbers so that code can detect the loader/host version */ 295 ficlSetEnv(bf_sys, "FreeBSD_version", __FreeBSD_version); 296 ficlSetEnv(bf_sys, "loader_version", bootprog_rev); 297 } 298 299 /* 300 * Feed a line of user input to the Forth interpreter 301 */ 302 static int 303 interp_forth_run(void *ctx, const char *line) 304 { 305 struct interp_forth_softc *softc; 306 int result; 307 308 softc = ctx; 309 310 result = ficlExec(softc->bf_vm, (char *)line); 311 312 DEBUG("ficlExec '%s' = %d", line, result); 313 switch (result) { 314 case VM_OUTOFTEXT: 315 case VM_ABORTQ: 316 case VM_QUIT: 317 case VM_ERREXIT: 318 break; 319 case VM_USEREXIT: 320 printf("No where to leave to!\n"); 321 break; 322 case VM_ABORT: 323 printf("Aborted!\n"); 324 break; 325 case BF_PARSE: 326 printf("Parse error!\n"); 327 break; 328 default: 329 if (command_errmsg != NULL) { 330 printf("%s\n", command_errmsg); 331 command_errmsg = NULL; 332 } 333 } 334 335 if (result == VM_USEREXIT) 336 panic("interpreter exit"); 337 setenv("interpret", softc->bf_vm->state ? "" : "OK", 1); 338 339 return (result); 340 } 341 342 static int 343 interp_forth_incl(void *ctx, const char *filename) 344 { 345 struct interp_forth_softc *softc; 346 int fd; 347 348 softc = ctx; 349 350 fd = open(filename, O_RDONLY); 351 if (fd == -1) { 352 /* Hihger layers print the error message */ 353 snprintf(command_errbuf, sizeof(command_errbuf), 354 "can't open %s\n", filename); 355 return (CMD_ERROR); 356 } 357 return (ficlExecFD(softc->bf_vm, fd)); 358 } 359 360 361 struct interp boot_interp_forth = { 362 .init = interp_forth_init, 363 .run = interp_forth_run, 364 .incl = interp_forth_incl, 365 .load_configs = default_load_config, 366 .context = &forth_softc 367 }; 368