Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "cpp.h"

/*
 * A hideset is a null-terminated array of Nlist pointers.
 * They are referred to by indices in the hidesets array.
 * Hideset 0 is empty.
 */

#define HSSIZ   32
typedef Nlist   **Hideset;
Hideset *hidesets;
int     nhidesets = 0;
int     maxhidesets = 3;
int     inserths(Hideset, Hideset, Nlist *);

/*
 * Test for membership in a hideset
 */
int
checkhideset(int hs, Nlist *np)
{
        Hideset hsp;

        if (hs>=nhidesets)
                abort();
        for (hsp = hidesets[hs]; *hsp; hsp++) {
                if (*hsp == np)
                        return 1;
        }
        return 0;
}

/*
 * Return the (possibly new) hideset obtained by adding np to hs.
 */
int
newhideset(int hs, Nlist *np)
{
        int i, len;
        Nlist *nhs[HSSIZ+3];
        Hideset hs1, hs2;

        len = inserths(nhs, hidesets[hs], np);
        for (i=0; i<nhidesets; i++) {
                for (hs1=nhs, hs2=hidesets[i]; *hs1==*hs2; hs1++, hs2++)
                        if (*hs1 == NULL)
                                return i;
        }
        if (len>=HSSIZ)
                return hs;
        if (nhidesets >= maxhidesets) {
                maxhidesets = 3*maxhidesets/2+1;
                hidesets = (Hideset *)realloc(hidesets, (sizeof (Hideset *))*maxhidesets);
        }
        hs1 = (Hideset)domalloc(len*sizeof(Hideset));
        memmove(hs1, nhs, len*sizeof(Hideset));
        hidesets[nhidesets] = hs1;
        return nhidesets++;
}

int
inserths(Hideset dhs, Hideset shs, Nlist *np)
{
        Hideset odhs = dhs;

        while (*shs && *shs < np)
                *dhs++ = *shs++;
        if (*shs != np)
                *dhs++ = np;
        do {
                *dhs++ = *shs;
        } while (*shs++);
        return dhs - odhs;
}

/*
 * Hideset union
 */
int
unionhideset(int hs1, int hs2)
{
        Hideset hp;

        for (hp = hidesets[hs2]; *hp; hp++)
                hs1 = newhideset(hs1, *hp);
        return hs1;
}

void
iniths(void)
{
        hidesets = (Hideset *)domalloc(maxhidesets*sizeof(Hideset *));
        hidesets[0] = (Hideset)domalloc(sizeof(Hideset));
        *hidesets[0] = NULL;
        nhidesets++;
}

void
prhideset(int hs)
{
        Hideset np;

        for (np = hidesets[hs]; *np; np++) {
                fprintf(stderr, (char*)(*np)->name, (*np)->len);
                fprintf(stderr, " ", 1);
        }
}