usr/src/usr.bin/m4/eval.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

#ifndef lint
static char sccsid[] = "@(#)eval.c      5.4 (Berkeley) 2/26/91";
#endif /* not lint */

/*
 * eval.c
 * Facility: m4 macro processor
 * by: oz
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mdef.h"
#include "extr.h"

extern ndptr lookup();

/*
 * eval - evaluate built-in macros.
 *        argc - number of elements in argv.
 *        argv - element vector :
 *                      argv[0] = definition of a user
 *                                macro or nil if built-in.
 *                      argv[1] = name of the macro or
 *                                built-in.
 *                      argv[2] = parameters to user-defined
 *                         .      macro or built-in.
 *                         .
 *
 * Note that the minimum value for argc is 3. A call in the form
 * of macro-or-builtin() will result in:
 *                      argv[0] = nullstr
 *                      argv[1] = macro-or-builtin
 *                      argv[2] = nullstr
 *
 */

eval (argv, argc, td)
register char *argv[];
register int argc;
register int  td;
{
        register int c, n;
        static int sysval;

#ifdef DEBUG
        printf("argc = %d\n", argc);
        for (n = 0; n < argc; n++)
                printf("argv[%d] = %s\n", n, argv[n]);
#endif
        /*
         * if argc == 3 and argv[2] is null,
         * then we have macro-or-builtin() type call.
         * We adjust argc to avoid further checking..
         *
         */
        if (argc == 3 && !*(argv[2]))
                argc--;

        switch (td & ~STATIC) {

        case DEFITYPE:
                if (argc > 2)
                        dodefine(argv[2], (argc > 3) ? argv[3] : null);
                break;

        case PUSDTYPE:
                if (argc > 2)
                        dopushdef(argv[2], (argc > 3) ? argv[3] : null);
                break;

        case DUMPTYPE:
                dodump(argv, argc);
                break;

        case EXPRTYPE:
                /*
                 * doexpr - evaluate arithmetic expression
                 *
                 */
                if (argc > 2)
                        pbnum(expr(argv[2]));
                break;

        case IFELTYPE:
                if (argc > 4)
                        doifelse(argv, argc);
                break;

        case IFDFTYPE:
                /*
                 * doifdef - select one of two alternatives based
                 *           on the existence of another definition
                 */
                if (argc > 3) {
                        if (lookup(argv[2]) != nil)
                                pbstr(argv[3]);
                        else if (argc > 4)
                                pbstr(argv[4]);
                }
                break;

        case LENGTYPE:
                /*
                 * dolen - find the length of the argument
                 *
                 */
                if (argc > 2)
                        pbnum((argc > 2) ? strlen(argv[2]) : 0);
                break;

        case INCRTYPE:
                /*
                 * doincr - increment the value of the argument
                 *
                 */
                if (argc > 2)
                        pbnum(atoi(argv[2]) + 1);
                break;

        case DECRTYPE:
                /*
                 * dodecr - decrement the value of the argument
                 *
                 */
                if (argc > 2)
                        pbnum(atoi(argv[2]) - 1);
                break;

        case SYSCTYPE:
                /*
                 * dosys - execute system command
                 *
                 */
                if (argc > 2)
                        sysval = system(argv[2]);
                break;

        case SYSVTYPE:
                /*
                 * dosysval - return value of the last system call.
                 *
                 */
                pbnum(sysval);
                break;

        case INCLTYPE:
                if (argc > 2)
                        if (!doincl(argv[2])) {
                                fprintf(stderr,"m4: %s: ",argv[2]);
                                error("cannot open for read.");
                        }
                break;

        case SINCTYPE:
                if (argc > 2)
                        (void) doincl(argv[2]);
                break;
#ifdef EXTENDED
        case PASTTYPE:
                if (argc > 2)
                        if (!dopaste(argv[2])) {
                                fprintf(stderr,"m4: %s: ",argv[2]);
                                error("cannot open for read.");
                        }
                break;

        case SPASTYPE:
                if (argc > 2)
                        (void) dopaste(argv[2]);
                break;
#endif
        case CHNQTYPE:
                dochq(argv, argc);
                break;

        case CHNCTYPE:
                dochc(argv, argc);
                break;

        case SUBSTYPE:
                /*
                 * dosub - select substring
                 *
                 */
                if (argc > 3)
                        dosub(argv,argc);
                break;

        case SHIFTYPE:
                /*
                 * doshift - push back all arguments except the
                 *           first one (i.e. skip argv[2])
                 */
                if (argc > 3) {
                        for (n = argc-1; n > 3; n--) {
                                putback(rquote);
                                pbstr(argv[n]);
                                putback(lquote);
                                putback(',');
                        }
                        putback(rquote);
                        pbstr(argv[3]);
                        putback(lquote);
                }
                break;

        case DIVRTYPE:
                if (argc > 2 && (n = atoi(argv[2])) != 0)
                        dodiv(n);
                else {
                        active = stdout;
                        oindex = 0;
                }
                break;

        case UNDVTYPE:
                doundiv(argv, argc);
                break;

        case DIVNTYPE:
                /*
                 * dodivnum - return the number of current
                 * output diversion
                 *
                 */
                pbnum(oindex);
                break;

        case UNDFTYPE:
                /*
                 * doundefine - undefine a previously defined
                 *              macro(s) or m4 keyword(s).
                 */
                if (argc > 2)
                        for (n = 2; n < argc; n++)
                                remhash(argv[n], ALL);
                break;

        case POPDTYPE:
                /*
                 * dopopdef - remove the topmost definitions of
                 *            macro(s) or m4 keyword(s).
                 */
                if (argc > 2)
                        for (n = 2; n < argc; n++)
                                remhash(argv[n], TOP);
                break;

        case MKTMTYPE:
                /*
                 * dotemp - create a temporary file
                 *
                 */
                if (argc > 2)
                        pbstr(mktemp(argv[2]));
                break;

        case TRNLTYPE:
                /*
                 * dotranslit - replace all characters in the
                 *              source string that appears in
                 *              the "from" string with the corresponding
                 *              characters in the "to" string.
                 *
                 */
                if (argc > 3) {
                        char temp[MAXTOK];
                        if (argc > 4)
                                map(temp, argv[2], argv[3], argv[4]);
                        else
                                map(temp, argv[2], argv[3], null);
                        pbstr(temp);
                }
                else
                    if (argc > 2)
                        pbstr(argv[2]);
                break;

        case INDXTYPE:
                /*
                 * doindex - find the index of the second argument
                 *           string in the first argument string.
                 *           -1 if not present.
                 */
                pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
                break;

        case ERRPTYPE:
                /*
                 * doerrp - print the arguments to stderr file
                 *
                 */
                if (argc > 2) {
                        for (n = 2; n < argc; n++)
                                fprintf(stderr,"%s ", argv[n]);
                        fprintf(stderr, "\n");
                }
                break;

        case DNLNTYPE:
                /*
                 * dodnl - eat-up-to and including newline
                 *
                 */
                while ((c = gpbc()) != '\n' && c != EOF)
                        ;
                break;

        case M4WRTYPE:
                /*
                 * dom4wrap - set up for wrap-up/wind-down activity
                 *
                 */
                m4wraps = (argc > 2) ? strdup(argv[2]) : null;
                break;

        case EXITTYPE:
                /*
                 * doexit - immediate exit from m4.
                 *
                 */
                exit((argc > 2) ? atoi(argv[2]) : 0);
                break;

        case DEFNTYPE:
                if (argc > 2)
                        for (n = 2; n < argc; n++)
                                dodefn(argv[n]);
                break;

        default:
                error("m4: major botch in eval.");
                break;
        }
}