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 36extern char bootprog_rev[]; 37 38/* #define BFORTH_DEBUG */ 39 40#ifdef BFORTH_DEBUG 41# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) 42#else 43# define DEBUG(fmt, args...) 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 64FICL_SYSTEM *bf_sys; 65FICL_VM *bf_vm; 66FICL_WORD *pInterp; 67 68/* 69 * Shim for taking commands from BF and passing them out to 'standard' 70 * argv/argc command functions. 71 */ 72static void 73bf_command(FICL_VM *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) && !strcmp(name, (*cmdp)->c_name)) 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 (stackPopINT(vm->pStack)) { 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 = stackPopINT(vm->pStack); 105 for (i = 0, len = 0; i < nstrings; i++) 106 len += stackFetch(vm->pStack, i * 2).i + 1; 107 line = malloc(strlen(name) + len + 1); 108 strcpy(line, name); 109 110 if (nstrings) 111 for (i = 0; i < nstrings; i++) { 112 len = stackPopINT(vm->pStack); 113 cp = stackPopPtr(vm->pStack); 114 strcat(line, " "); 115 strncat(line, cp, len); 116 } 117 } else { 118 /* Get remainder of invocation */ 119 tail = vmGetInBuf(vm); 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 vmUpdateTib(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 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 */ 253void 254bf_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", 282 (bootprog_rev[0] - '0') * 10 + (bootprog_rev[2] - '0')); 283 284 /* try to load and run init file if present */ 285 if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) { 286 (void)ficlExecFD(bf_vm, fd); 287 close(fd); 288 } 289 290 /* Do this last, so /boot/boot.4th can change it */ 291 pInterp = ficlLookup(bf_sys, "interpret"); 292} 293 294/* 295 * Feed a line of user input to the Forth interpreter 296 */ 297int 298bf_run(char *line) 299{ 300 int result; 301 302 result = ficlExec(bf_vm, line); 303 304 DEBUG("ficlExec '%s' = %d", line, result); 305 switch (result) { 306 case VM_OUTOFTEXT: 307 case VM_ABORTQ: 308 case VM_QUIT: 309 case VM_ERREXIT: 310 break; 311 case VM_USEREXIT: 312 printf("No where to leave to!\n"); 313 break; 314 case VM_ABORT: 315 printf("Aborted!\n"); 316 break; 317 case BF_PARSE: 318 printf("Parse error!\n"); 319 break; 320 default: 321 /* Hopefully, all other codes filled this buffer */ 322 printf("%s\n", command_errmsg); 323 } 324 325 if (result == VM_USEREXIT) 326 panic("interpreter exit"); 327 setenv("interpret", bf_vm->state ? "" : "OK", 1); 328 329 return result; 330} 331