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yap-6.3/C/clause_list.c
2014-01-19 21:15:05 +00:00

170 lines
3.5 KiB
C

#include "Yap.h"
#include "clause.h"
#include "tracer.h"
#ifdef YAPOR
#include "or.macros.h"
#endif /* YAPOR */
#include "clause_list.h"
/* need to fix overflow handling */
static void
mk_blob(int sz USES_REGS)
{
MP_INT *dst;
HR[0] = (CELL)FunctorBigInt;
HR[1] = CLAUSE_LIST;
dst = (MP_INT *)(HR+2);
dst->_mp_size = 0L;
dst->_mp_alloc = sz;
HR += (1+sizeof(MP_INT)/sizeof(CELL));
HR[sz] = EndSpecials;
HR += sz+1;
}
static CELL *
extend_blob(CELL *start, int sz USES_REGS)
{
UInt osize;
MP_INT *dst;
if (HR + sz > ASP)
return NULL;
dst = (MP_INT *)(start+2);
osize = dst->_mp_alloc;
start += (1+sizeof(MP_INT)/sizeof(CELL));
start[sz+osize] = EndSpecials;
dst->_mp_alloc += sz;
HR += sz;
return start+osize;
}
/*init of ClasuseList*/
X_API clause_list_t
Yap_ClauseListInit(clause_list_t in)
{
CACHE_REGS
in->n = 0;
in->start = HR;
mk_blob(0 PASS_REGS);
in->end = HR;
return in;
}
/*add clause to ClauseList
returns FALSE on error*/
X_API int
Yap_ClauseListExtend(clause_list_t cl, void * clause, void *pred)
{
CACHE_REGS
PredEntry *ap = (PredEntry *)pred;
/* fprintf(stderr,"cl=%p\n",clause); */
if (cl->end != HR)
return FALSE;
if (cl->n == 0) {
void **ptr;
if (!(ptr = (void **)extend_blob(cl->start,1 PASS_REGS))) return FALSE;
ptr[0] = clause;
} else if (cl->n == 1) {
yamop **ptr;
yamop *code_p, *fclause;
if (!(ptr = (yamop **)extend_blob(cl->start,2*(CELL)NEXTOP((yamop *)NULL,Otapl)/sizeof(CELL)-1 PASS_REGS))) return FALSE;
fclause = ptr[-1];
code_p = (yamop *)(ptr-1);
code_p->opc = Yap_opcode(_try_clause);
code_p->u.Otapl.d = fclause;
code_p->u.Otapl.s = ap->ArityOfPE;
code_p->u.Otapl.p = ap;
#ifdef TABLING
code_p->u.Otapl.te = ap->TableOfPred;
#endif
#ifdef YAPOR
INIT_YAMOP_LTT(code_p, 0);
#endif /* YAPOR */
code_p = NEXTOP(code_p,Otapl);
code_p->opc = Yap_opcode(_trust);
code_p->u.Otapl.d = clause;
code_p->u.Otapl.s = ap->ArityOfPE;
code_p->u.Otapl.p = ap;
#ifdef TABLING
code_p->u.Otapl.te = ap->TableOfPred;
#endif
#ifdef YAPOR
INIT_YAMOP_LTT(code_p, 0);
#endif /* YAPOR */
} else {
yamop *code_p;
if (!(code_p = (yamop *)extend_blob(cl->start,((CELL)NEXTOP((yamop *)NULL,Otapl))/sizeof(CELL) PASS_REGS))) return FALSE;
code_p->opc = Yap_opcode(_trust);
code_p->u.Otapl.d = clause;
code_p->u.Otapl.s = ap->ArityOfPE;
code_p->u.Otapl.p = ap;
#ifdef TABLING
code_p->u.Otapl.te = ap->TableOfPred;
#endif
#ifdef YAPOR
INIT_YAMOP_LTT(code_p, 0);
#endif /* YAPOR */
code_p = PREVOP(code_p,Otapl);
code_p->opc = Yap_opcode(_retry);
}
cl->end = HR;
cl->n++;
return TRUE;
}
/*closes the clause list*/
X_API void
Yap_ClauseListClose(clause_list_t cl)
{
/* no need to do nothing */
}
/*destroys the clause list freeing memory*/
X_API int
Yap_ClauseListDestroy(clause_list_t cl)
{
CACHE_REGS
if (cl->end != HR)
return FALSE;
HR = cl->start;
return TRUE;
}
/*destroys clause list and returns only first clause*/
X_API void *
Yap_ClauseListToClause(clause_list_t cl)
{
CACHE_REGS
void **ptr;
if (cl->end != HR)
return NULL;
if (cl->n != 1)
return NULL;
if (!(ptr = (void **)extend_blob(cl->start,0 PASS_REGS))) return NULL;
return ptr[-1];
}
/*return pointer to start of try-retry-trust sequence*/
X_API void *
Yap_ClauseListCode(clause_list_t cl)
{
CELL *ptr;
ptr = (CELL *)cl->start;
ptr += (1+sizeof(MP_INT)/sizeof(CELL));
return (void *)ptr;
}
/* where to fail */
X_API void *
Yap_FAILCODE(void)
{
return (void *)FAILCODE;
}