2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h> /* to pick up __FreeBSD_version */
33 #include "bootstrap.h"
36 extern unsigned bootprog_rev;
39 /* #define BFORTH_DEBUG */
42 #define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
44 #define DEBUG(fmt, args...)
48 * Eventually, all builtin commands throw codes must be defined
49 * elsewhere, possibly bootstrap.h. For now, just this code, used
50 * just in this file, it is getting defined.
55 * FreeBSD loader default dictionary cells
58 #define BF_DICTSIZE 10000
62 * BootForth Interface to Ficl Forth interpreter.
69 * Shim for taking commands from BF and passing them out to 'standard'
70 * argv/argc command functions.
73 bf_command(FICL_VM *vm)
75 char *name, *line, *tail, *cp;
77 struct bootblk_command **cmdp;
83 /* Get the name of the current word */
84 name = vm->runningWord->name;
86 /* Find our command structure */
88 SET_FOREACH(cmdp, Xcommand_set) {
89 if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name))
93 panic("callout for unknown command '%s'", name);
95 /* Check whether we have been compiled or are being interpreted */
96 if (stackPopINT(vm->pStack)) {
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
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);
111 for (i = 0; i < nstrings; i++) {
112 len = stackPopINT(vm->pStack);
113 cp = stackPopPtr(vm->pStack);
115 strncat(line, cp, len);
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++)
123 line = malloc(strlen(name) + len + 2);
127 strncat(line, tail, len);
128 vmUpdateTib(vm, tail + len);
131 DEBUG("cmd '%s'", line);
133 command_errmsg = command_errbuf;
134 command_errbuf[0] = 0;
135 if (!parse(&argc, &argv, line)) {
136 result = (cmd)(argc, argv);
144 printf("%s\n", command_errmsg);
147 panic("%s", command_errmsg);
152 * If there was error during nested ficlExec(), we may no longer have
153 * valid environment to return. Throw all exceptions from here.
155 if (result != CMD_OK)
158 /* This is going to be thrown!!! */
159 stackPushINT(vm->pStack,result);
163 * Replace a word definition (a builtin command) with another
166 * - Throw error results instead of returning them on the stack
167 * - Pass a flag indicating whether the word was compiled or is
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:
176 * : example ls ; immediate
177 * : problem example ; \ "ls" gets executed while compiling
178 * example \ "ls" gets executed while interpreting
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.
184 * The problem arises when you tick the builtin. For example:
186 * : example-1 ['] ls postpone literal ; immediate
187 * : example-2 example-1 execute ; immediate
188 * : problem example-2 ;
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.
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.
201 * : example ['] my-ls catch ;
203 * So, with the below implementation, here is a summary of the behavior
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,
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,
220 * : ex-8 postpone ls ; immediate \ same as ex-2
221 * : ex-9 postpone ls ; \ same as ex-3
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
227 * (if you edit this definition, pay attention to trailing spaces after
228 * each word -- I warned you! :-) )
230 #define BUILTIN_CONSTRUCTOR \
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 */ \
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 */ \
251 * Initialise the Forth interpreter, create all our commands as words.
256 struct bootblk_command **cmdp;
257 char create_buf[41]; /* 31 characters-long builtins */
260 bf_sys = ficlInitSystem(BF_DICTSIZE);
261 bf_vm = ficlNewVM(bf_sys);
263 /* Put all private definitions in a "builtins" vocabulary */
264 ficlExec(bf_vm, "vocabulary builtins also builtins definitions");
266 /* Builtin constructor word */
267 ficlExec(bf_vm, BUILTIN_CONSTRUCTOR);
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");
277 ficlExec(bf_vm, "only forth definitions");
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", bootprog_rev);
283 /* try to load and run init file if present */
284 if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) {
285 #ifdef LOADER_VERIEXEC
286 if (verify_file(fd, "/boot/boot.4th", 0, VE_GUESS) < 0) {
291 (void)ficlExecFD(bf_vm, fd);
297 * Feed a line of user input to the Forth interpreter
300 bf_run(const char *line)
305 * ficl would require extensive changes to accept a const char *
306 * interface. Instead, cast it away here and hope for the best.
307 * We know at the present time the caller for us in the boot
308 * forth loader can tolerate the string being modified because
309 * the string is passed in here and then not touched again.
311 result = ficlExec(bf_vm, __DECONST(char *, line));
313 DEBUG("ficlExec '%s' = %d", line, result);
321 printf("No where to leave to!\n");
324 printf("Aborted!\n");
327 printf("Parse error!\n");
330 if (command_errmsg != NULL) {
331 printf("%s\n", command_errmsg);
332 command_errmsg = NULL;
336 if (result == VM_USEREXIT)
337 panic("interpreter exit");
338 setenv("interpret", bf_vm->state ? "" : "OK", 1);
347 setenv("script.lang", "forth", 1);
349 /* Read our default configuration. */
350 interp_include("/boot/loader.rc");
354 interp_run(const char *input)
357 bf_vm->sourceID.i = 0;
358 return bf_run(input);
362 * Header prepended to each line. The text immediately follows the header.
363 * We try to make this short in order to save memory -- the loader has
364 * limited memory available, and some of the forth files are very long.
368 struct includeline *next;
373 interp_include(const char *filename)
375 struct includeline *script, *se, *sp;
376 char input[256]; /* big enough? */
379 int prevsrcid, fd, line;
381 if (((fd = open(filename, O_RDONLY)) == -1)) {
382 snprintf(command_errbuf, sizeof(command_errbuf),
383 "can't open '%s': %s", filename, strerror(errno));
387 #ifdef LOADER_VERIEXEC
388 if (verify_file(fd, filename, 0, VE_GUESS) < 0) {
390 sprintf(command_errbuf,"can't verify '%s'", filename);
395 * Read the script into memory.
400 while (fgetstr(input, sizeof(input), fd) >= 0) {
403 /* Allocate script line structure and copy line, flags */
405 continue; /* ignore empty line, save memory */
406 sp = malloc(sizeof(struct includeline) + strlen(cp) + 1);
407 /* On malloc failure (it happens!), free as much as possible and exit */
409 while (script != NULL) {
411 script = script->next;
414 snprintf(command_errbuf, sizeof(command_errbuf),
415 "file '%s' line %d: memory allocation failure - aborting",
420 strcpy(sp->text, cp);
423 if (script == NULL) {
435 prevsrcid = bf_vm->sourceID.i;
436 bf_vm->sourceID.i = fd;
438 for (sp = script; sp != NULL; sp = sp->next) {
439 res = bf_run(sp->text);
440 if (res != VM_OUTOFTEXT) {
441 snprintf(command_errbuf, sizeof(command_errbuf),
442 "Error while including %s, in the line:\n%s",
449 bf_vm->sourceID.i = prevsrcid;
451 while (script != NULL) {
453 script = script->next;