minix3/commands/cawf/expand.c

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2020-02-21 00:59:27 +05:30
/*
* expand.c - macro expansion functions for cawf(1)
*/
/*
* Copyright (c) 1991 Purdue University Research Foundation,
* West Lafayette, Indiana 47907. All rights reserved.
*
* Written by Victor A. Abell <abe@mace.cc.purdue.edu>, Purdue
* University Computing Center. Not derived from licensed software;
* derived from awf(1) by Henry Spencer of the University of Toronto.
*
* Permission is granted to anyone to use this software for any
* purpose on any computer system, and to alter it and redistribute
* it freely, subject to the following restrictions:
*
* 1. The author is not responsible for any consequences of use of
* this software, even if they arise from flaws in it.
*
* 2. The origin of this software must not be misrepresented, either
* by explicit claim or by omission. Credits must appear in the
* documentation.
*
* 3. Altered versions must be plainly marked as such, and must not
* be misrepresented as being the original software. Credits must
* appear in the documentation.
*
* 4. This notice may not be removed or altered.
*/
#include "cawf.h"
/*
* Expand(line) - expand macro or if/ie/el line
*/
void
Expand(line)
unsigned char *line;
{
unsigned char buf[2*MAXLINE]; /* line buffer */
unsigned char cmd[4]; /* nroff command */
int cmdl; /* command length */
int cmdx; /* cmd index in Macrotab[] */
int cond = 0; /* conditional statuses */
int i, j; /* temporary indexes */
int iflen; /* if statement length */
int invert; /* inversion status */
unsigned char *lp; /* line pointer */
int mx = -1; /* Macrotab[] index */
int n1, n2; /* temporary numbers */
int nargs = 0; /* number of arguments */
int nleft = 0; /* number of macro lines left */
char op; /* comparison operator */
int prevcond; /* previous condition (for else's) */
int ptr = -1; /* Macrotxt[] index */
int quote; /* quoted string status */
unsigned char *s1, *s2; /* temporary string pointers */
(void) sprintf((char *)buf, ".^= %d %s", NR, (char *)Inname);
Pass2(buf);
for (lp = line; *lp; ) {
invert = regexec(Pat[1].pat, lp);
prevcond = cond;
cond = 0;
if (regexec(Pat[0].pat, lp) == 0) {
/*
* Not conditional: - ! "^[.'](i[ef]|el)"
*/
cond = 1;
iflen = 0;
}
else if (regexec(Pat[2].pat, lp)) {
/*
* Argument count comparison: -
* "^[.']i[ef] !?\\n\(\.\$(>|>=|=|<|<=)[0-9] "
*/
iflen = strlen(".if \\n(.$=n ") + invert;
s1 = lp + iflen - 3;
op = *s1++;
if (*s1 == '=' && (op == '>' || op == '<')) {
s1++;
op = (op == '>') ? 'G' : 'L';
}
n1 = (int)(*s1 - '0');
switch (op) {
case '=':
if ((nargs - 1) == n1)
cond = 1;
break;
case '<':
if ((nargs - 1) < n1)
cond = 1;
break;
case '>':
if ((nargs - 1) > n1)
cond = 1;
break;
case 'G': /* >= */
if ((nargs - 1) >= n1)
cond = 1;
break;
case 'L': /* <= */
if ((nargs - 1) <= n1)
cond = 1;
}
}
else if (regexec(Pat[3].pat, lp)) {
/*
* Argument string comparison: - "^[.']i[ef] !?'\\\$[0-9]'[^']*' "
*/
iflen = strlen(".if '\\$n'") + invert;
n1 = (int)(*(lp + iflen - 2) - '0');
if (n1 >= 0 && n1 < nargs)
s1 = Args[n1];
else
s1 = (unsigned char *)"";
if ((s2 = (unsigned char *)strchr((char *)lp
+ iflen, '\''))
!= NULL) {
n2 = s2 - lp - iflen;
if (strncmp((char *)s1, (char *)lp + iflen, n2)
== 0)
cond = 1;
iflen += n2 + 2;
}
}
else if (regexec(Pat[4].pat, lp)) {
/*
* Nroff or troff: - "^[.']i[ef] !?[nt] "
*/
iflen = strlen(".if n ") + invert;
if (*(lp + iflen - 2) == 'n')
cond = 1;
}
else if ((*lp == '.' || *lp == '\'')
&& strncmp((char *)lp+1, "el ", 3) == 0) {
/*
* Else clause: - "^[.']el "
*/
cond = 1 - prevcond;
iflen = 4;
}
else {
/*
* Unknown conditional:
*/
cond = 1;
iflen = 0;
(void) sprintf((char *)buf,
".tm unknown .if/.ie form: %s", (char *)lp);
lp = buf;
}
/*
* Handle conditional. If case is true, locate predicate.
* If predicate is an .i[ef], process it.
*/
if (invert)
cond = 1 - cond;
if (cond && iflen > 0) {
lp += iflen;
if (regexec(Pat[15].pat, lp))
continue;
}
/*
* Do argument substitution, as necessary.
*/
if (cond && regexec(Pat[5].pat, lp)) { /* "\$[0-9]" ??? */
for (s1 = buf;;) {
if ((n1 = Pat[5].pat->startp[0] - lp) > 0) {
(void) strncpy((char *)s1, (char *)lp,
n1);
s1 += n1;
}
*s1 = '\0';
lp = Pat[5].pat->endp[0];
n1 = (int)(*(lp-1) - '0');
if (n1 >= 0 && n1 < nargs) {
(void) strcpy((char *)s1,
(char *)Args[n1]);
s1 += strlen((char *)Args[n1]);
}
if (*lp == '\0')
break;
if (regexec(Pat[5].pat, lp) == 0) {
(void) strcpy((char *)s1, (char *)lp);
break;
}
}
lp = buf;
}
/*
* Check for nroff command.
*/
if (cond) {
cmdl = 0;
if (cond && (*lp == '.' || *lp == '\'')) {
if ((*cmd = *(lp+1)) != '\0') {
cmdl++;
if ((*(cmd+1) = *(lp+2)) == ' ')
*(cmd+1) = '\0';
else
cmdl++;
}
}
cmd[cmdl] = '\0';
}
if (cond == 0)
i = i; /* do nothing if condition is false */
else if (cmdl == 0 || ((cmdx = Findmacro(cmd, 0)) < 0))
Pass2(lp);
else if (Sp >= MAXSP) {
(void) sprintf((char *)buf, " macro nesting > %d",
MAXSP);
Error(WARN, LINE, (char *)buf, NULL);
} else {
/*
* Stack macros.
*/
/*
* Push stack.
*/
Sp++;
Nleftstack[Sp] = nleft;
Ptrstack[Sp] = ptr;
Mxstack[Sp] = mx;
Condstack[Sp] = cond;
for (i = 10*Sp, j = 0; j < 10; i++, j++) {
Argstack[i] = Args[j];
Args[j] = NULL;
}
/*
* Start new stack entry.
*/
mx = cmdx;
ptr = Macrotab[mx].bx;
cond = 0;
nleft = Macrotab[mx].ct;
Args[0] = Newstr(cmd);
/*
* Parse arguments.
*/
for (s1 = lp + cmdl + 1, nargs = 1; nargs < 10;) {
while (*s1 && (*s1 == ' ' || *s1 == '\t'))
s1++;
if (*s1 == '\0')
break;
if (*s1 == '"') {
s1++;
quote = 1;
} else
quote = 0;
for (s2 = buf;;) {
if (!quote && (*s1 == ' ' || *s1 == '\t')) {
*s2 = '\0';
break;
}
if ((*s2 = *s1) == '\0')
break;
s1++;
if (quote && *s2 == '"') {
*s2 = '\0';
break;
}
s2++;
}
if (buf[0])
Args[nargs++] = Newstr(buf);
}
for (i = nargs; i < 10; i++) {
Args[i] = NULL;
}
}
/*
* Unstack completed macros.
*/
while (nleft <= 0 && Sp >= 0) {
nleft = Nleftstack[Sp];
mx = Mxstack[Sp];
ptr = Ptrstack[Sp];
cond = Condstack[Sp];
for (i = 10*Sp, j = 0, nargs = -1; j < 10; i++, j++) {
Free(&Args[j]);
if ((Args[j] = Argstack[i]) != NULL)
nargs = j;
}
Sp--;
nargs++;
}
/*
* Get next line.
*/
if (nleft > 0) {
lp = Macrotxt[ptr++];
nleft--;
} else
lp = (unsigned char *)"";
}
(void) sprintf((char *)buf, ".^# %d %s", NR, (char *)Inname);
Pass2(buf);
}