/*

* eval.c

* Facility: m4 macro processor

* by: oz

*/

#include "mdef.h"

#include "extr.h"

/*

* 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

*

*/

void 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;

#if unix || vms

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;

#endif

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) ? strsave(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;

}

}