ref: c3ba64f6935322f09b6de5c2285544fd471c605d
dir: /sys/src/cmd/cpp/macro.c/
#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "cpp.h"
/*
* do a macro definition. tp points to the name being defined in the line
*/
void
dodefine(Tokenrow *trp)
{
Token *tp;
Nlist *np;
Tokenrow *def, *args;
int dots;
dots = 0;
tp = trp->tp+1;
if (tp>=trp->lp || tp->type!=NAME) {
error(ERROR, "#defined token is not a name");
return;
}
np = lookup(tp, 1);
if (np->flag&ISUNCHANGE) {
error(ERROR, "#defined token %t can't be redefined", tp);
return;
}
/* collect arguments */
tp += 1;
args = NULL;
if (tp<trp->lp && tp->type==LP && tp->wslen==0) {
/* macro with args */
int narg = 0;
tp += 1;
args = new(Tokenrow);
maketokenrow(2, args);
if (tp->type!=RP) {
int err = 0;
for (;;) {
Token *atp;
if (tp->type == ELLIPS)
dots++;
else if (tp->type!=NAME) {
err++;
break;
}
if (narg>=args->max)
growtokenrow(args);
for (atp=args->bp; atp<args->lp; atp++)
if (atp->len==tp->len
&& strncmp((char*)atp->t, (char*)tp->t, tp->len)==0)
error(ERROR, "Duplicate macro argument");
*args->lp++ = *tp;
narg++;
tp += 1;
if (tp->type==RP)
break;
if (dots)
error(ERROR, "arguments after '...' in macro");
if (tp->type!=COMMA) {
err++;
break;
}
tp += 1;
}
if (err) {
error(ERROR, "Syntax error in macro parameters");
return;
}
}
tp += 1;
}
trp->tp = tp;
if (((trp->lp)-1)->type==NL)
trp->lp -= 1;
def = normtokenrow(trp);
if (np->flag&ISDEFINED) {
if (comparetokens(def, np->vp)
|| (np->ap==NULL) != (args==NULL)
|| np->ap && comparetokens(args, np->ap))
error(ERROR, "Macro redefinition of %t", trp->bp+2);
}
if (args) {
Tokenrow *tap;
tap = normtokenrow(args);
dofree(args->bp);
args = tap;
}
np->ap = args;
np->vp = def;
np->flag |= ISDEFINED;
if(dots)
np->flag |= ISVARMAC;
}
/*
* Definition received via -D or -U
*/
void
doadefine(Tokenrow *trp, int type)
{
Nlist *np;
static unsigned char one[] = "1";
static Token onetoken[1] = {{ NUMBER, 0, 0, 0, 1, one }};
static Tokenrow onetr = { onetoken, onetoken, onetoken+1, 1 };
trp->tp = trp->bp;
if (type=='U') {
if (trp->lp-trp->tp != 2 || trp->tp->type!=NAME)
goto syntax;
if ((np = lookup(trp->tp, 0)) == NULL)
return;
np->flag &= ~ISDEFINED;
return;
}
if (trp->tp >= trp->lp || trp->tp->type!=NAME)
goto syntax;
np = lookup(trp->tp, 1);
np->flag |= ISDEFINED;
trp->tp += 1;
if (trp->tp >= trp->lp || trp->tp->type==END) {
np->vp = &onetr;
return;
}
if (trp->tp->type!=ASGN)
goto syntax;
trp->tp += 1;
if ((trp->lp-1)->type == END)
trp->lp -= 1;
np->vp = normtokenrow(trp);
return;
syntax:
error(FATAL, "Illegal -D or -U argument %r", trp);
}
/*
* Do macro expansion in a row of tokens.
* Flag is NULL if more input can be gathered.
*/
void
expandrow(Tokenrow *trp, char *flag)
{
Token *tp;
Nlist *np;
if (flag)
setsource(flag, -1, "");
for (tp = trp->tp; tp<trp->lp; ) {
if (tp->type!=NAME
|| quicklook(tp->t[0], tp->len>1?tp->t[1]:0)==0
|| (np = lookup(tp, 0))==NULL
|| (np->flag&(ISDEFINED|ISMAC))==0
|| tp->hideset && checkhideset(tp->hideset, np)) {
tp++;
continue;
}
trp->tp = tp;
if (np->val==KDEFINED) {
tp->type = DEFINED;
if ((tp+1)<trp->lp && (tp+1)->type==NAME)
(tp+1)->type = NAME1;
else if ((tp+3)<trp->lp && (tp+1)->type==LP
&& (tp+2)->type==NAME && (tp+3)->type==RP)
(tp+2)->type = NAME1;
else
error(ERROR, "Incorrect syntax for `defined'");
tp++;
continue;
}
if (np->flag&ISMAC)
builtin(trp, np->val);
else
expand(trp, np);
tp = trp->tp;
}
if (flag)
unsetsource();
}
/*
* Expand the macro whose name is np, at token trp->tp, in the tokenrow.
* Return trp->tp at the first token next to be expanded
* (ordinarily the beginning of the expansion)
*/
void
expand(Tokenrow *trp, Nlist *np)
{
int ntokc, narg, i, hs;
Tokenrow *atr[NARG+1];
Tokenrow ntr;
Token *tp;
copytokenrow(&ntr, np->vp); /* copy macro value */
if (np->ap==NULL) { /* parameterless */
ntokc = 1;
/* substargs for handling # and ## */
atr[0] = nil;
substargs(np, &ntr, atr, trp->tp->hideset);
} else {
ntokc = gatherargs(trp, atr, (np->flag&ISVARMAC) ? rowlen(np->ap) : 0, &narg);
if (narg<0) { /* not actually a call (no '(') */
/* gatherargs has already pushed trp->tr to the next token */
return;
}
if (narg != rowlen(np->ap)) {
error(ERROR, "Disagreement in number of macro arguments");
trp->tp->hideset = newhideset(trp->tp->hideset, np);
trp->tp += ntokc;
return;
}
substargs(np, &ntr, atr, trp->tp->hideset); /* put args into replacement */
for (i=0; i<narg; i++) {
dofree(atr[i]->bp);
dofree(atr[i]);
}
}
hs = newhideset(trp->tp->hideset, np);
for (tp=ntr.bp; tp<ntr.lp; tp++) { /* distribute hidesets */
if (tp->type==NAME) {
if (tp->hideset==0)
tp->hideset = hs;
else
tp->hideset = unionhideset(tp->hideset, hs);
}
}
ntr.tp = ntr.bp;
insertrow(trp, ntokc, &ntr);
trp->tp -= rowlen(&ntr);
free(ntr.bp);
}
/*
* Gather an arglist, starting in trp with tp pointing at the macro name.
* Return total number of tokens passed, stash number of args found.
* trp->tp is not changed relative to the tokenrow.
*/
int
gatherargs(Tokenrow *trp, Tokenrow **atr, int dots, int *narg)
{
int parens = 1;
int ntok = 0;
Token *bp, *lp;
Tokenrow ttr;
int ntokp;
int needspace;
*narg = -1; /* means that there is no macro call */
/* look for the ( */
for (;;) {
trp->tp++;
ntok++;
if (trp->tp >= trp->lp) {
gettokens(trp, 0);
if ((trp->lp-1)->type==END) {
trp->lp -= 1;
if (*narg>=0)
trp->tp -= ntok;
return ntok;
}
}
if (trp->tp->type==LP)
break;
if (trp->tp->type!=NL)
return ntok;
}
*narg = 0;
ntok++;
ntokp = ntok;
trp->tp++;
/* search for the terminating ), possibly extending the row */
needspace = 0;
while (parens>0) {
if (trp->tp >= trp->lp)
gettokens(trp, 0);
if (needspace) {
needspace = 0;
makespace(trp);
}
if (trp->tp->type==END) {
trp->lp -= 1;
trp->tp -= ntok;
error(ERROR, "EOF in macro arglist");
return ntok;
}
if (trp->tp->type==NL) {
trp->tp += 1;
adjustrow(trp, -1);
trp->tp -= 1;
makespace(trp);
needspace = 1;
continue;
}
if (trp->tp->type==LP)
parens++;
else if (trp->tp->type==RP)
parens--;
trp->tp++;
ntok++;
}
trp->tp -= ntok;
/* Now trp->tp won't move underneath us */
lp = bp = trp->tp+ntokp;
for (; parens>=0; lp++) {
if (lp->type == LP) {
parens++;
continue;
}
if (lp->type==RP)
parens--;
if (lp->type==DSHARP)
lp->type = DSHARP1; /* ## not special in arg */
if ((lp->type==COMMA && parens==0) || (parens<0 && (lp-1)->type!=LP)) {
if (lp->type == COMMA && dots && *narg == dots-1)
continue;
if (*narg>=NARG-1)
error(FATAL, "Sorry, too many macro arguments");
ttr.bp = ttr.tp = bp;
ttr.lp = lp;
atr[(*narg)++] = normtokenrow(&ttr);
bp = lp+1;
}
}
return ntok;
}
int
ispaste(Tokenrow *rtr, Token **ap, Token **an, int *ntok)
{
*ap = nil;
*an = nil;
/* EMPTY ## tok */
if (rtr->tp->type == DSHARP && rtr->tp != rtr->bp)
rtr->tp--;
/* tok ## tok */
if(rtr->tp + 1 != rtr->lp && rtr->tp[1].type == DSHARP) {
*ap = rtr->tp;
if(rtr->tp + 2 != rtr->lp)
*an = rtr->tp + 2;
*ntok = 1 + (*ap != nil) + (*an != nil);
return 1;
}
return 0;
}
/*
* substitute the argument list into the replacement string
* This would be simple except for ## and #
*/
void
substargs(Nlist *np, Tokenrow *rtr, Tokenrow **atr, int hideset)
{
Tokenrow ttr, rp, rn;
Token *tp, *ap, *an, *pp, *pn;
int ntok, argno, hs;
for (rtr->tp=rtr->bp; rtr->tp<rtr->lp; ) {
if(rtr->tp->hideset && checkhideset(hideset, np)) {
rtr->tp++;
} else if (rtr->tp->type==SHARP) { /* string operator */
tp = rtr->tp;
rtr->tp += 1;
if ((argno = lookuparg(np, rtr->tp))<0) {
error(ERROR, "# not followed by macro parameter");
continue;
}
ntok = 1 + (rtr->tp - tp);
rtr->tp = tp;
insertrow(rtr, ntok, stringify(atr[argno]));
} else if (ispaste(rtr, &ap, &an, &ntok)) { /* first token, just do the next one */
pp = ap;
memset(&rp, 0, sizeof(rp));
pn = an;
memset(&rn, 0, sizeof(rp));
if (ap && (argno = lookuparg(np, ap)) >= 0){
pp = nil;
rp = *atr[argno];
if(rp.tp != rp.lp)
pp = --rp.lp;
}
if (an && (argno = lookuparg(np, an)) >= 0) {
pn = nil;
rn = *atr[argno];
if(rn.tp != rn.lp)
pn = rn.bp++;
}
glue(&ttr, pp, pn);
insertrow(rtr, 0, &rp);
insertrow(rtr, ntok, &ttr);
insertrow(rtr, 0, &rn);
free(ttr.bp);
} else if (rtr->tp->type==NAME) {
if((argno = lookuparg(np, rtr->tp)) >= 0) {
if (rtr->tp < rtr->bp) {
error(ERROR, "access out of bounds");
continue;
}
copytokenrow(&ttr, atr[argno]);
expandrow(&ttr, "<macro>");
insertrow(rtr, 1, &ttr);
free(ttr.bp);
} else {
maketokenrow(1, &ttr);
ttr.lp = ttr.tp + 1;
*ttr.tp = *rtr->tp;
hs = newhideset(rtr->tp->hideset, np);
if(hideset == 0)
ttr.tp->hideset = hs;
else
ttr.tp->hideset = unionhideset(hideset, hs);
expandrow(&ttr, (char*)np->name);
for(tp = ttr.bp; tp != ttr.lp; tp++)
if(tp->type == COMMA)
tp->type = XCOMMA;
insertrow(rtr, 1, &ttr);
dofree(ttr.bp);
}
} else {
rtr->tp++;
}
}
}
/*
* Evaluate the ## operators in a tokenrow
*/
void
glue(Tokenrow *ntr, Token *tp, Token *tn)
{
int np, nn;
char *tt, *p, *n;
np = tp ? tp->len : 0;
nn = tn ? tn->len : 0;
tt = domalloc(np + nn + 1);
if(tp)
memcpy(tt, tp->t, tp->len);
if(tn)
memcpy(tt+np, tn->t, tn->len);
tt[np+nn] = '\0';
setsource("<##>", -1, tt);
maketokenrow(3, ntr);
gettokens(ntr, 1);
unsetsource();
dofree(tt);
if (np + nn == 0) {
ntr->lp = ntr->bp;
} else {
if (ntr->lp - ntr->bp!=2 || ntr->bp->type==UNCLASS) {
p = tp ? (char*)tp->t : "<empty>";
n = tn ? (char*)tn->t : "<empty>";
error(WARNING, "Bad token %r produced by %s ## %s", &ntr, p, n);
}
ntr->lp = ntr->bp+1;
}
makespace(ntr);
}
/*
* tp is a potential parameter name of macro mac;
* look it up in mac's arglist, and if found, return the
* corresponding index in the argname array. Return -1 if not found.
*/
int
lookuparg(Nlist *mac, Token *tp)
{
Token *ap;
if (tp->type!=NAME || mac->ap==NULL)
return -1;
if((mac->flag & ISVARMAC) && strcmp((char*)tp->t, "__VA_ARGS__") == 0)
return rowlen(mac->ap) - 1;
for (ap=mac->ap->bp; ap<mac->ap->lp; ap++) {
if (ap->len==tp->len && strncmp((char*)ap->t,(char*)tp->t,ap->len)==0)
return ap - mac->ap->bp;
}
return -1;
}
/*
* Return a quoted version of the tokenrow (from # arg)
*/
#define STRLEN 512
Tokenrow *
stringify(Tokenrow *vp)
{
static Token t = { STRING };
static Tokenrow tr = { &t, &t, &t+1, 1 };
Token *tp;
uchar s[STRLEN];
uchar *sp = s, *cp;
int i, instring;
*sp++ = '"';
for (tp = vp->bp; tp < vp->lp; tp++) {
instring = tp->type==STRING || tp->type==CCON;
if (sp+2*tp->len >= &s[STRLEN-10]) {
error(ERROR, "Stringified macro arg is too long");
break;
}
if (tp->wslen && (tp->flag&XPWS)==0)
*sp++ = ' ';
for (i=0, cp=tp->t; i<tp->len; i++) {
if (instring && (*cp=='"' || *cp=='\\'))
*sp++ = '\\';
*sp++ = *cp++;
}
}
*sp++ = '"';
*sp = '\0';
sp = s;
t.len = strlen((char*)sp);
t.t = newstring(sp, t.len, 0);
return &tr;
}
/*
* expand a builtin name
*/
void
builtin(Tokenrow *trp, int biname)
{
char *op;
Token *tp;
Source *s;
tp = trp->tp;
trp->tp++;
/* need to find the real source */
s = cursource;
while (s && s->fd==-1)
s = s->next;
if (s==NULL)
s = cursource;
/* most are strings */
tp->type = STRING;
if (tp->wslen) {
*outp++ = ' ';
tp->wslen = 1;
}
op = outp;
*op++ = '"';
switch (biname) {
case KLINENO:
tp->type = NUMBER;
op = outnum(op-1, s->line);
break;
case KFILE:
strcpy(op, s->filename);
op += strlen(s->filename);
break;
case KDATE:
strncpy(op, curtime+4, 7);
strncpy(op+7, curtime+24, 4); /* Plan 9 asctime disobeys standard */
op += 11;
break;
case KTIME:
strncpy(op, curtime+11, 8);
op += 8;
break;
default:
error(ERROR, "cpp botch: unknown internal macro");
return;
}
if (tp->type==STRING)
*op++ = '"';
tp->t = (uchar*)outp;
tp->len = op - outp;
outp = op;
}