/*- * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/param.h> /* to pick up __FreeBSD_version */ #include <string.h> #include <stand.h> #include "bootstrap.h" #include "ficl.h" INTERP_DEFINE("4th"); /* #define BFORTH_DEBUG */ #ifdef BFORTH_DEBUG #define DPRINTF(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args) #else #define DPRINTF(fmt, args...) ((void)0) #endif /* * Eventually, all builtin commands throw codes must be defined * elsewhere, possibly bootstrap.h. For now, just this code, used * just in this file, it is getting defined. */ #define BF_PARSE 100 /* * FreeBSD loader default dictionary cells */ #ifndef BF_DICTSIZE #define BF_DICTSIZE 10000 #endif /* * BootForth Interface to Ficl Forth interpreter. */ FICL_SYSTEM *bf_sys; FICL_VM *bf_vm; /* * Shim for taking commands from BF and passing them out to 'standard' * argv/argc command functions. */ static void bf_command(FICL_VM *vm) { char *name, *line, *tail, *cp; size_t len; struct bootblk_command **cmdp; bootblk_cmd_t *cmd; int nstrings, i; int argc, result; char **argv; /* Get the name of the current word */ name = vm->runningWord->name; /* Find our command structure */ cmd = NULL; SET_FOREACH(cmdp, Xcommand_set) { if (((*cmdp)->c_name != NULL) && !strcmp(name, (*cmdp)->c_name)) cmd = (*cmdp)->c_fn; } if (cmd == NULL) panic("callout for unknown command '%s'", name); /* Check whether we have been compiled or are being interpreted */ if (stackPopINT(vm->pStack)) { /* * Get parameters from stack, in the format: * an un ... a2 u2 a1 u1 n -- * Where n is the number of strings, a/u are pairs of * address/size for strings, and they will be concatenated * in LIFO order. */ nstrings = stackPopINT(vm->pStack); for (i = 0, len = 0; i < nstrings; i++) len += stackFetch(vm->pStack, i * 2).i + 1; line = malloc(strlen(name) + len + 1); strcpy(line, name); if (nstrings) for (i = 0; i < nstrings; i++) { len = stackPopINT(vm->pStack); cp = stackPopPtr(vm->pStack); strcat(line, " "); strncat(line, cp, len); } } else { /* Get remainder of invocation */ tail = vmGetInBuf(vm); for (cp = tail, len = 0; cp != vm->tib.end && *cp != 0 && *cp != '\n'; cp++, len++) ; line = malloc(strlen(name) + len + 2); strcpy(line, name); if (len > 0) { strcat(line, " "); strncat(line, tail, len); vmUpdateTib(vm, tail + len); } } DPRINTF("cmd '%s'", line); command_errmsg = command_errbuf; command_errbuf[0] = 0; if (!parse(&argc, &argv, line)) { result = (cmd)(argc, argv); free(argv); } else { result=BF_PARSE; } switch (result) { case CMD_CRIT: printf("%s\n", command_errmsg); command_errmsg = NULL; break; case CMD_FATAL: panic("%s", command_errmsg); } free(line); /* * If there was error during nested ficlExec(), we may no longer have * valid environment to return. Throw all exceptions from here. */ if (result != CMD_OK) vmThrow(vm, result); /* This is going to be thrown!!! */ stackPushINT(vm->pStack,result); } /* * Replace a word definition (a builtin command) with another * one that: * * - Throw error results instead of returning them on the stack * - Pass a flag indicating whether the word was compiled or is * being interpreted. * * There is one major problem with builtins that cannot be overcome * in anyway, except by outlawing it. We want builtins to behave * differently depending on whether they have been compiled or they * are being interpreted. Notice that this is *not* the interpreter's * current state. For example: * * : example ls ; immediate * : problem example ; \ "ls" gets executed while compiling * example \ "ls" gets executed while interpreting * * Notice that, though the current state is different in the two * invocations of "example", in both cases "ls" has been * *compiled in*, which is what we really want. * * The problem arises when you tick the builtin. For example: * * : example-1 ['] ls postpone literal ; immediate * : example-2 example-1 execute ; immediate * : problem example-2 ; * example-2 * * We have no way, when we get EXECUTEd, of knowing what our behavior * should be. Thus, our only alternative is to "outlaw" this. See RFI * 0007, and ANS Forth Standard's appendix D, item 6.7 for a related * problem, concerning compile semantics. * * The problem is compounded by the fact that "' builtin CATCH" is valid * and desirable. The only solution is to create an intermediary word. * For example: * * : my-ls ls ; * : example ['] my-ls catch ; * * So, with the below implementation, here is a summary of the behavior * of builtins: * * ls -l \ "interpret" behavior, ie, * \ takes parameters from TIB * : ex-1 s" -l" 1 ls ; \ "compile" behavior, ie, * \ takes parameters from the stack * : ex-2 ['] ls catch ; immediate \ undefined behavior * : ex-3 ['] ls catch ; \ undefined behavior * ex-2 ex-3 \ "interpret" behavior, * \ catch works * : ex-4 ex-2 ; \ "compile" behavior, * \ catch does not work * : ex-5 ex-3 ; immediate \ same as ex-2 * : ex-6 ex-3 ; \ same as ex-3 * : ex-7 ['] ex-1 catch ; \ "compile" behavior, * \ catch works * : ex-8 postpone ls ; immediate \ same as ex-2 * : ex-9 postpone ls ; \ same as ex-3 * * As the definition below is particularly tricky, and it's side effects * must be well understood by those playing with it, I'll be heavy on * the comments. * * (if you edit this definition, pay attention to trailing spaces after * each word -- I warned you! :-) ) */ #define BUILTIN_CONSTRUCTOR \ ": builtin: " \ ">in @ " /* save the tib index pointer */ \ "' " /* get next word's xt */ \ "swap >in ! " /* point again to next word */ \ "create " /* create a new definition of the next word */ \ ", " /* save previous definition's xt */ \ "immediate " /* make the new definition an immediate word */ \ \ "does> " /* Now, the *new* definition will: */ \ "state @ if " /* if in compiling state: */ \ "1 postpone literal " /* pass 1 flag to indicate compile */ \ "@ compile, " /* compile in previous definition */ \ "postpone throw " /* throw stack-returned result */ \ "else " /* if in interpreting state: */ \ "0 swap " /* pass 0 flag to indicate interpret */ \ "@ execute " /* call previous definition */ \ "throw " /* throw stack-returned result */ \ "then ; " /* * Initialise the Forth interpreter, create all our commands as words. */ void bf_init(void) { struct bootblk_command **cmdp; char create_buf[41]; /* 31 characters-long builtins */ int fd; bf_sys = ficlInitSystem(BF_DICTSIZE); bf_vm = ficlNewVM(bf_sys); /* Put all private definitions in a "builtins" vocabulary */ ficlExec(bf_vm, "vocabulary builtins also builtins definitions"); /* Builtin constructor word */ ficlExec(bf_vm, BUILTIN_CONSTRUCTOR); /* make all commands appear as Forth words */ SET_FOREACH(cmdp, Xcommand_set) { ficlBuild(bf_sys, (char *)(*cmdp)->c_name, bf_command, FW_DEFAULT); ficlExec(bf_vm, "forth definitions builtins"); sprintf(create_buf, "builtin: %s", (*cmdp)->c_name); ficlExec(bf_vm, create_buf); ficlExec(bf_vm, "builtins definitions"); } ficlExec(bf_vm, "only forth definitions"); /* Export some version numbers so that code can detect the loader/host version */ ficlSetEnv(bf_sys, "FreeBSD_version", __FreeBSD_version); ficlSetEnv(bf_sys, "loader_version", bootprog_rev); /* try to load and run init file if present */ if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) { #ifdef LOADER_VERIEXEC if (verify_file(fd, "/boot/boot.4th", 0, VE_GUESS, __func__) < 0) { close(fd); return; } #endif (void)ficlExecFD(bf_vm, fd); close(fd); } } /* * Feed a line of user input to the Forth interpreter */ static int bf_run(const char *line) { int result; /* * ficl would require extensive changes to accept a const char * * interface. Instead, cast it away here and hope for the best. * We know at the present time the caller for us in the boot * forth loader can tolerate the string being modified because * the string is passed in here and then not touched again. */ result = ficlExec(bf_vm, __DECONST(char *, line)); DPRINTF("ficlExec '%s' = %d", line, result); switch (result) { case VM_OUTOFTEXT: case VM_ABORTQ: case VM_QUIT: case VM_ERREXIT: break; case VM_USEREXIT: printf("No where to leave to!\n"); break; case VM_ABORT: printf("Aborted!\n"); break; case BF_PARSE: printf("Parse error!\n"); break; default: if (command_errmsg != NULL) { printf("%s\n", command_errmsg); command_errmsg = NULL; } } if (result == VM_USEREXIT) panic("interpreter exit"); setenv("interpret", bf_vm->state ? "" : "OK", 1); return (result); } static bool preinit_run = false; void interp_preinit(void) { if (preinit_run) return; setenv("script.lang", "forth", 1); bf_init(); preinit_run = true; } void interp_init(void) { /* Read our default configuration. */ interp_include("/boot/loader.rc"); } int interp_run(const char *input) { bf_vm->sourceID.i = 0; return bf_run(input); } /* * Header prepended to each line. The text immediately follows the header. * We try to make this short in order to save memory -- the loader has * limited memory available, and some of the forth files are very long. */ struct includeline { struct includeline *next; char text[0]; }; int interp_include(const char *filename) { struct includeline *script, *se, *sp; char input[256]; /* big enough? */ int res; char *cp; int prevsrcid, fd, line; if (((fd = open(filename, O_RDONLY)) == -1)) { snprintf(command_errbuf, sizeof(command_errbuf), "can't open '%s': %s", filename, strerror(errno)); return(CMD_ERROR); } #ifdef LOADER_VERIEXEC if (verify_file(fd, filename, 0, VE_GUESS, __func__) < 0) { close(fd); sprintf(command_errbuf,"can't verify '%s'", filename); return(CMD_ERROR); } #endif /* * Read the script into memory. */ script = se = NULL; line = 0; while (fgetstr(input, sizeof(input), fd) >= 0) { line++; cp = input; /* Allocate script line structure and copy line, flags */ if (*cp == '\0') continue; /* ignore empty line, save memory */ sp = malloc(sizeof(struct includeline) + strlen(cp) + 1); /* On malloc failure (it happens!), free as much as possible and exit */ if (sp == NULL) { while (script != NULL) { se = script; script = script->next; free(se); } snprintf(command_errbuf, sizeof(command_errbuf), "file '%s' line %d: memory allocation failure - aborting", filename, line); close(fd); return (CMD_ERROR); } strcpy(sp->text, cp); sp->next = NULL; if (script == NULL) { script = sp; } else { se->next = sp; } se = sp; } close(fd); /* * Execute the script */ prevsrcid = bf_vm->sourceID.i; bf_vm->sourceID.i = fd; res = CMD_OK; for (sp = script; sp != NULL; sp = sp->next) { res = bf_run(sp->text); if (res != VM_OUTOFTEXT) { snprintf(command_errbuf, sizeof(command_errbuf), "Error while including %s, in the line:\n%s", filename, sp->text); res = CMD_ERROR; break; } else res = CMD_OK; } bf_vm->sourceID.i = prevsrcid; while (script != NULL) { se = script; script = script->next; free(se); } return(res); }
