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;
38 /* #define BFORTH_DEBUG */
41 #define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
43 #define DEBUG(fmt, args...)
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.
54 * FreeBSD loader default dictionary cells
57 #define BF_DICTSIZE 10000
61 * BootForth Interface to Ficl Forth interpreter.
68 * Shim for taking commands from BF and passing them out to 'standard'
69 * argv/argc command functions.
72 bf_command(FICL_VM *vm)
74 char *name, *line, *tail, *cp;
76 struct bootblk_command **cmdp;
82 /* Get the name of the current word */
83 name = vm->runningWord->name;
85 /* Find our command structure */
87 SET_FOREACH(cmdp, Xcommand_set) {
88 if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name))
92 panic("callout for unknown command '%s'", name);
94 /* Check whether we have been compiled or are being interpreted */
95 if (stackPopINT(vm->pStack)) {
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
103 nstrings = stackPopINT(vm->pStack);
104 for (i = 0, len = 0; i < nstrings; i++)
105 len += stackFetch(vm->pStack, i * 2).i + 1;
106 line = malloc(strlen(name) + len + 1);
110 for (i = 0; i < nstrings; i++) {
111 len = stackPopINT(vm->pStack);
112 cp = stackPopPtr(vm->pStack);
114 strncat(line, cp, len);
117 /* Get remainder of invocation */
118 tail = vmGetInBuf(vm);
119 for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++)
122 line = malloc(strlen(name) + len + 2);
126 strncat(line, tail, len);
127 vmUpdateTib(vm, tail + len);
130 DEBUG("cmd '%s'", line);
132 command_errmsg = command_errbuf;
133 command_errbuf[0] = 0;
134 if (!parse(&argc, &argv, line)) {
135 result = (cmd)(argc, argv);
143 printf("%s\n", command_errmsg);
146 panic("%s\n", command_errmsg);
151 * If there was error during nested ficlExec(), we may no longer have
152 * valid environment to return. Throw all exceptions from here.
154 if (result != CMD_OK)
157 /* This is going to be thrown!!! */
158 stackPushINT(vm->pStack,result);
162 * Replace a word definition (a builtin command) with another
165 * - Throw error results instead of returning them on the stack
166 * - Pass a flag indicating whether the word was compiled or is
169 * There is one major problem with builtins that cannot be overcome
170 * in anyway, except by outlawing it. We want builtins to behave
171 * differently depending on whether they have been compiled or they
172 * are being interpreted. Notice that this is *not* the interpreter's
173 * current state. For example:
175 * : example ls ; immediate
176 * : problem example ; \ "ls" gets executed while compiling
177 * example \ "ls" gets executed while interpreting
179 * Notice that, though the current state is different in the two
180 * invocations of "example", in both cases "ls" has been
181 * *compiled in*, which is what we really want.
183 * The problem arises when you tick the builtin. For example:
185 * : example-1 ['] ls postpone literal ; immediate
186 * : example-2 example-1 execute ; immediate
187 * : problem example-2 ;
190 * We have no way, when we get EXECUTEd, of knowing what our behavior
191 * should be. Thus, our only alternative is to "outlaw" this. See RFI
192 * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related
193 * problem, concerning compile semantics.
195 * The problem is compounded by the fact that "' builtin CATCH" is valid
196 * and desirable. The only solution is to create an intermediary word.
200 * : example ['] my-ls catch ;
202 * So, with the below implementation, here is a summary of the behavior
205 * ls -l \ "interpret" behavior, ie,
206 * \ takes parameters from TIB
207 * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie,
208 * \ takes parameters from the stack
209 * : ex-2 ['] ls catch ; immediate \ undefined behavior
210 * : ex-3 ['] ls catch ; \ undefined behavior
211 * ex-2 ex-3 \ "interpret" behavior,
213 * : ex-4 ex-2 ; \ "compile" behavior,
214 * \ catch does not work
215 * : ex-5 ex-3 ; immediate \ same as ex-2
216 * : ex-6 ex-3 ; \ same as ex-3
217 * : ex-7 ['] ex-1 catch ; \ "compile" behavior,
219 * : ex-8 postpone ls ; immediate \ same as ex-2
220 * : ex-9 postpone ls ; \ same as ex-3
222 * As the definition below is particularly tricky, and it's side effects
223 * must be well understood by those playing with it, I'll be heavy on
226 * (if you edit this definition, pay attention to trailing spaces after
227 * each word -- I warned you! :-) )
229 #define BUILTIN_CONSTRUCTOR \
231 ">in @ " /* save the tib index pointer */ \
232 "' " /* get next word's xt */ \
233 "swap >in ! " /* point again to next word */ \
234 "create " /* create a new definition of the next word */ \
235 ", " /* save previous definition's xt */ \
236 "immediate " /* make the new definition an immediate word */ \
238 "does> " /* Now, the *new* definition will: */ \
239 "state @ if " /* if in compiling state: */ \
240 "1 postpone literal " /* pass 1 flag to indicate compile */ \
241 "@ compile, " /* compile in previous definition */ \
242 "postpone throw " /* throw stack-returned result */ \
243 "else " /* if in interpreting state: */ \
244 "0 swap " /* pass 0 flag to indicate interpret */ \
245 "@ execute " /* call previous definition */ \
246 "throw " /* throw stack-returned result */ \
250 * Initialise the Forth interpreter, create all our commands as words.
255 struct bootblk_command **cmdp;
256 char create_buf[41]; /* 31 characters-long builtins */
259 bf_sys = ficlInitSystem(BF_DICTSIZE);
260 bf_vm = ficlNewVM(bf_sys);
262 /* Put all private definitions in a "builtins" vocabulary */
263 ficlExec(bf_vm, "vocabulary builtins also builtins definitions");
265 /* Builtin constructor word */
266 ficlExec(bf_vm, BUILTIN_CONSTRUCTOR);
268 /* make all commands appear as Forth words */
269 SET_FOREACH(cmdp, Xcommand_set) {
270 ficlBuild(bf_sys, (char *)(*cmdp)->c_name, bf_command, FW_DEFAULT);
271 ficlExec(bf_vm, "forth definitions builtins");
272 sprintf(create_buf, "builtin: %s", (*cmdp)->c_name);
273 ficlExec(bf_vm, create_buf);
274 ficlExec(bf_vm, "builtins definitions");
276 ficlExec(bf_vm, "only forth definitions");
278 /* Export some version numbers so that code can detect the loader/host version */
279 ficlSetEnv(bf_sys, "FreeBSD_version", __FreeBSD_version);
280 ficlSetEnv(bf_sys, "loader_version", bootprog_rev);
282 /* try to load and run init file if present */
283 if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) {
284 (void)ficlExecFD(bf_vm, fd);
290 * Feed a line of user input to the Forth interpreter
293 bf_run(const char *line)
298 * ficl would require extensive changes to accept a const char *
299 * interface. Instead, cast it away here and hope for the best.
300 * We know at the present time the caller for us in the boot
301 * forth loader can tolerate the string being modified because
302 * the string is passed in here and then not touched again.
304 result = ficlExec(bf_vm, __DECONST(char *, line));
306 DEBUG("ficlExec '%s' = %d", line, result);
314 printf("No where to leave to!\n");
317 printf("Aborted!\n");
320 printf("Parse error!\n");
323 if (command_errmsg != NULL) {
324 printf("%s\n", command_errmsg);
325 command_errmsg = NULL;
329 if (result == VM_USEREXIT)
330 panic("interpreter exit");
331 setenv("interpret", bf_vm->state ? "" : "OK", 1);
340 setenv("script.lang", "forth", 1);
342 /* Read our default configuration. */
343 interp_include("/boot/loader.rc");
347 interp_run(const char *input)
350 bf_vm->sourceID.i = 0;
351 return bf_run(input);
355 * Header prepended to each line. The text immediately follows the header.
356 * We try to make this short in order to save memory -- the loader has
357 * limited memory available, and some of the forth files are very long.
361 struct includeline *next;
366 interp_include(const char *filename)
368 struct includeline *script, *se, *sp;
369 char input[256]; /* big enough? */
372 int prevsrcid, fd, line;
374 if (((fd = open(filename, O_RDONLY)) == -1)) {
375 snprintf(command_errbuf, sizeof(command_errbuf),
376 "can't open '%s': %s", filename, strerror(errno));
381 * Read the script into memory.
386 while (fgetstr(input, sizeof(input), fd) >= 0) {
389 /* Allocate script line structure and copy line, flags */
391 continue; /* ignore empty line, save memory */
392 sp = malloc(sizeof(struct includeline) + strlen(cp) + 1);
393 /* On malloc failure (it happens!), free as much as possible and exit */
395 while (script != NULL) {
397 script = script->next;
400 snprintf(command_errbuf, sizeof(command_errbuf),
401 "file '%s' line %d: memory allocation failure - aborting",
406 strcpy(sp->text, cp);
409 if (script == NULL) {
421 prevsrcid = bf_vm->sourceID.i;
422 bf_vm->sourceID.i = fd;
424 for (sp = script; sp != NULL; sp = sp->next) {
425 res = bf_run(sp->text);
426 if (res != VM_OUTOFTEXT) {
427 snprintf(command_errbuf, sizeof(command_errbuf),
428 "Error while including %s, in the line:\n%s",
435 bf_vm->sourceID.i = prevsrcid;
437 while (script != NULL) {
439 script = script->next;