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yap-6.3/C/modules.c
2016-03-29 01:55:12 +01:00

542 lines
13 KiB
C

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
File: modules.c *
* Last rev: *
* mods: *
* comments: module support *
* *
*************************************************************************/
#ifdef SCCSLookupSystemModule
static char SccsId[] = "%W% %G%";
#endif
#include "Yap.h"
#include "YapHeap.h"
#include "Yatom.h"
static Int current_module(USES_REGS1);
static Int current_module1(USES_REGS1);
static ModEntry *LookupModule(Term a);
static ModEntry *LookupSystemModule(Term a);
static ModEntry *GetModuleEntry(Atom at USES_REGS);
static ModEntry *FetchModuleEntry(Atom at);
/**
* initialize module data-structure
*
* @param to parent module (CurrentModule)
* @param ae module name.
*
* @return a new module structure
*/ /** */
static ModEntry *initMod(AtomEntry *toname, AtomEntry *ae) {
CACHE_REGS
ModEntry *n, *parent;
if (toname == NULL)
parent = NULL;
else {
parent = FetchModuleEntry(toname);
}
n = (ModEntry *)Yap_AllocAtomSpace(sizeof(*n));
INIT_RWLOCK(n->ModRWLock);
n->KindOfPE = ModProperty;
n->PredForME = NULL;
n->NextME = CurrentModules;
CurrentModules = n;
n->AtomOfME = ae;
n->OwnerFile = Yap_ConsultingFile(PASS_REGS1);
AddPropToAtom(ae, (PropEntry *)n);
Yap_setModuleFlags(n, parent);
return n;
}
/**
* get predicate entry for ap/arity; create it if neccessary
*
* @param[in] at
*
* @return module descriptorxs
*/
static ModEntry *GetModuleEntry(Atom at USES_REGS) {
Prop p0;
AtomEntry *ae = RepAtom(at);
READ_LOCK(ae->ARWLock);
p0 = ae->PropsOfAE;
while (p0) {
ModEntry *me = RepModProp(p0);
if (me->KindOfPE == ModProperty) {
READ_UNLOCK(ae->ARWLock);
return me;
}
p0 = me->NextOfPE;
}
READ_UNLOCK(ae->ARWLock);
return initMod(
(CurrentModule == PROLOG_MODULE ? NULL : AtomOfTerm(CurrentModule)), at);
}
/** get entry for ap/arity; assumes one is there. */
static ModEntry *FetchModuleEntry(Atom at) {
Prop p0;
AtomEntry *ae = RepAtom(at);
READ_LOCK(ae->ARWLock);
p0 = ae->PropsOfAE;
while (p0) {
ModEntry *me = RepModProp(p0);
if (me->KindOfPE == ModProperty) {
READ_UNLOCK(ae->ARWLock);
return me;
}
p0 = me->NextOfPE;
}
READ_UNLOCK(ae->ARWLock);
return NULL;
}
Term Yap_getUnknownModule(ModEntry *m) {
if (m && m->flags & UNKNOWN_ERROR) {
return TermError;
} else if (m && m->flags & UNKNOWN_WARNING) {
return TermWarning;
} else if (m && m->flags & UNKNOWN_FAST_FAIL) {
return TermFastFail;
} else {
return TermFail;
}
}
bool Yap_getUnknown(Term mod) {
ModEntry *m = LookupModule(mod);
return Yap_getUnknownModule(m);
}
bool Yap_CharacterEscapes(Term mt) {
CACHE_REGS
if (mt == PROLOG_MODULE)
mt = TermProlog;
return GetModuleEntry(AtomOfTerm(mt) PASS_REGS)->flags & M_CHARESCAPE;
}
#define ByteAdr(X) ((char *)&(X))
Term Yap_Module_Name(PredEntry *ap) {
CACHE_REGS
if (!ap)
return TermUser;
if (!ap->ModuleOfPred)
/* If the system predicate is a meta-call I should return the
module for the metacall, which I will suppose has to be
reachable from the current module anyway.
So I will return the current module in case the system
predicate is a meta-call. Otherwise it will still work.
*/
return TermProlog;
else {
return ap->ModuleOfPred;
}
}
static ModEntry *LookupSystemModule(Term a) {
CACHE_REGS
Atom at;
ModEntry *me;
/* prolog module */
if (a == 0) {
a = TermProlog;
}
at = AtomOfTerm(a);
me = GetModuleEntry(at PASS_REGS);
if (!me)
return NULL;
me->flags |= M_SYSTEM;
me->OwnerFile = Yap_ConsultingFile(PASS_REGS1);
return me;
}
static ModEntry *LookupModule(Term a) {
CACHE_REGS
Atom at;
ModEntry *me;
/* prolog module */
if (a == 0) {
return GetModuleEntry(AtomProlog PASS_REGS);
}
at = AtomOfTerm(a);
me = GetModuleEntry(at PASS_REGS);
return me;
}
bool Yap_isSystemModule(Term a) {
ModEntry *me = LookupModule(a);
return me != NULL && me->flags & M_SYSTEM;
}
Term Yap_Module(Term tmod) {
LookupModule(tmod);
return tmod;
}
ModEntry *Yap_GetModuleEntry(Term mod) {
ModEntry *me;
if (!(me = LookupModule(mod)))
return NULL;
return me;
}
Term Yap_GetModuleFromEntry(ModEntry *me) {
return MkAtomTerm(me->AtomOfME);
;
}
struct pred_entry *Yap_ModulePred(Term mod) {
ModEntry *me;
if (!(me = LookupModule(mod)))
return NULL;
return me->PredForME;
}
void Yap_NewModulePred(Term mod, struct pred_entry *ap) {
ModEntry *me;
if (!(me = LookupModule(mod)))
return;
WRITE_LOCK(me->ModRWLock);
ap->NextPredOfModule = me->PredForME;
me->PredForME = ap;
WRITE_UNLOCK(me->ModRWLock);
}
static Int
current_module(USES_REGS1) { /* $current_module(Old,N) */
Term t;
if (CurrentModule) {
if (!Yap_unify_constant(ARG1, CurrentModule))
return FALSE;
} else {
if (!Yap_unify_constant(ARG1, TermProlog))
return FALSE;
}
t = Deref(ARG2);
if (IsVarTerm(t) || !IsAtomTerm(t))
return FALSE;
if (t == TermProlog) {
CurrentModule = PROLOG_MODULE;
} else {
// make it very clear that t inherits from cm.
LookupModule(t);
CurrentModule = t;
}
LOCAL_SourceModule = CurrentModule;
return TRUE;
}
static Int change_module(USES_REGS1) { /* $change_module(N) */
Term mod = Deref(ARG1);
LookupModule(mod);
CurrentModule = mod;
LOCAL_SourceModule = mod;
return TRUE;
}
static Int current_module1(USES_REGS1) { /* $current_module(Old)
*/
if (CurrentModule)
return Yap_unify_constant(ARG1, CurrentModule);
return Yap_unify_constant(ARG1, TermProlog);
}
static Int cont_current_module(USES_REGS1) {
ModEntry *imod = AddressOfTerm(EXTRA_CBACK_ARG(1, 1)), *next;
Term t = MkAtomTerm(imod->AtomOfME);
next = imod->NextME;
/* ARG1 is unbound */
Yap_unify(ARG1, t);
if (!next)
cut_succeed();
EXTRA_CBACK_ARG(1, 1) = MkAddressTerm(next);
return TRUE;
}
static Int init_current_module(
USES_REGS1) { /* current_module(?ModuleName) */
Term t = Deref(ARG1);
if (!IsVarTerm(t)) {
if (!IsAtomTerm(t)) {
Yap_Error(TYPE_ERROR_ATOM, t, "module name must be an atom");
return FALSE;
}
if (FetchModuleEntry(AtomOfTerm(t)) != NULL)
cut_succeed();
cut_fail();
}
EXTRA_CBACK_ARG(1, 1) = MkIntegerTerm((Int)CurrentModules);
return cont_current_module(PASS_REGS1);
}
static Int cont_ground_module(USES_REGS1) {
ModEntry *imod = AddressOfTerm(EXTRA_CBACK_ARG(3, 1)), *next;
Term t2 = MkAtomTerm(imod->AtomOfME);
next = imod->NextME;
/* ARG2 is unbound */
if (!next)
cut_succeed();
EXTRA_CBACK_ARG(3, 1) = MkAddressTerm(next);
return Yap_unify(ARG2, t2);
}
static Int init_ground_module(USES_REGS1) {
/* current_module(?ModuleName) */
Term t1 = Deref(ARG1), tmod = CurrentModule, t3;
if (tmod == PROLOG_MODULE) {
tmod = TermProlog;
}
t3 = Yap_YapStripModule(t1, &tmod);
if (!t3) {
Yap_Error(TYPE_ERROR_CALLABLE, t3, "trying to obtain module");
return FALSE;
}
if (!IsVarTerm(tmod)) {
if (!IsAtomTerm(tmod)) {
Yap_Error(TYPE_ERROR_ATOM, tmod, "module name must be an atom");
cut_fail();
}
if (FetchModuleEntry(AtomOfTerm(tmod)) != NULL && Yap_unify(tmod, ARG2) &&
Yap_unify(t3, ARG3)) {
cut_succeed();
}
cut_fail();
}
if (!Yap_unify(ARG2, tmod) || !Yap_unify(ARG3, t3)) {
cut_fail();
}
// make sure we keep the binding
B->cp_tr = TR;
B->cp_h = HR;
EXTRA_CBACK_ARG(3, 1) = MkAddressTerm(CurrentModules);
return cont_ground_module(PASS_REGS1);
}
/**
* @pred system_module( + _Mod_)
*
* @param module
*
* @return
*/
static Int is_system_module(USES_REGS1) {
Term t;
if (IsVarTerm(t = Deref(ARG1))) {
return false;
}
if (!IsAtomTerm(t)) {
Yap_Error(TYPE_ERROR_ATOM, t, "load_files/2");
return false;
}
return Yap_isSystemModule(t);
}
static Int new_system_module(USES_REGS1) {
ModEntry *me;
Term t;
if (IsVarTerm(t = Deref(ARG1))) {
Yap_Error(INSTANTIATION_ERROR, t, NULL);
return false;
}
if (!IsAtomTerm(t)) {
Yap_Error(TYPE_ERROR_ATOM, t, NULL);
return false;
}
if ((me = LookupSystemModule(t)))
me->OwnerFile = Yap_ConsultingFile(PASS_REGS1);
return me != NULL;
}
static Int strip_module(USES_REGS1) {
Term t1 = Deref(ARG1), tmod = CurrentModule;
if (tmod == PROLOG_MODULE) {
tmod = TermProlog;
}
t1 = Yap_StripModule(t1, &tmod);
if (!t1) {
Yap_Error(TYPE_ERROR_CALLABLE, t1, "trying to obtain module");
return FALSE;
}
return Yap_unify(ARG3, t1) && Yap_unify(ARG2, tmod);
}
Term Yap_YapStripModule(Term t, Term *modp) {
CACHE_REGS
Term tmod;
if (modp)
tmod = *modp;
else {
tmod = CurrentModule;
if (tmod == PROLOG_MODULE) {
tmod = TermProlog;
}
}
restart:
if (IsVarTerm(t) || !IsApplTerm(t)) {
if (modp)
*modp = tmod;
return t;
} else {
Functor fun = FunctorOfTerm(t);
if (fun == FunctorModule) {
Term t1 = ArgOfTerm(1, t);
tmod = t1;
if (!IsVarTerm(tmod) && !IsAtomTerm(tmod)) {
return 0L;
}
t = ArgOfTerm(2, t);
goto restart;
}
if (modp)
*modp = tmod;
return t;
}
return 0L;
}
static Int yap_strip_module(USES_REGS1) {
Term t1 = Deref(ARG1), tmod = CurrentModule;
if (tmod == PROLOG_MODULE) {
tmod = TermProlog;
}
t1 = Yap_YapStripModule(t1, &tmod);
if (!t1) {
Yap_Error(TYPE_ERROR_CALLABLE, t1, "trying to obtain module");
return FALSE;
}
return Yap_unify(ARG3, t1) && Yap_unify(ARG2, tmod);
}
static Int context_module(USES_REGS1) {
yamop *parentcp = P;
CELL *yenv;
PredEntry *ap = EnvPreg(parentcp);
if (ap->ModuleOfPred && !(ap->PredFlags & MetaPredFlag))
return Yap_unify(ARG1, ap->ModuleOfPred);
parentcp = CP;
yenv = ENV;
do {
ap = EnvPreg(parentcp);
if (ap->ModuleOfPred && !(ap->PredFlags & MetaPredFlag))
return Yap_unify(ARG1, ap->ModuleOfPred);
parentcp = (yamop *)yenv[E_CP];
yenv = (CELL *)yenv[E_E];
} while (yenv);
return Yap_unify(ARG1, CurrentModule);
}
/**
* @pred source_module(-Mod)
*
* @param Mod is the current text source module.
*
* : _Mod_ is the current read-in or source module.
*/
static Int source_module(USES_REGS1) {
if (LOCAL_SourceModule == PROLOG_MODULE) {
return Yap_unify(ARG1, TermProlog);
}
return Yap_unify(ARG1, LOCAL_SourceModule);
}
Term Yap_StripModule(Term t, Term *modp) {
CACHE_REGS
Term tmod;
if (modp)
tmod = *modp;
else {
tmod = CurrentModule;
if (tmod == PROLOG_MODULE) {
tmod = TermProlog;
}
}
restart:
if (IsVarTerm(t) || !IsApplTerm(t)) {
if (modp)
*modp = tmod;
return t;
} else {
Functor fun = FunctorOfTerm(t);
if (fun == FunctorModule) {
Term t1 = ArgOfTerm(1, t);
if (IsVarTerm(t1)) {
*modp = tmod;
return t;
}
tmod = t1;
if (!IsVarTerm(tmod) && !IsAtomTerm(tmod)) {
return 0L;
}
t = ArgOfTerm(2, t);
goto restart;
}
if (modp)
*modp = tmod;
return t;
}
return 0L;
}
void Yap_InitModulesC(void) {
Yap_InitCPred("$current_module", 2, current_module,
SafePredFlag | SyncPredFlag);
Yap_InitCPred("$current_module", 1, current_module1,
SafePredFlag | SyncPredFlag);
Yap_InitCPred("$change_module", 1, change_module,
SafePredFlag | SyncPredFlag);
Yap_InitCPred("strip_module", 3, strip_module, SafePredFlag | SyncPredFlag);
Yap_InitCPred("source_module", 1, source_module, SafePredFlag | SyncPredFlag);
Yap_InitCPred("$yap_strip_module", 3, yap_strip_module,
SafePredFlag | SyncPredFlag);
Yap_InitCPred("context_module", 1, context_module, 0);
Yap_InitCPred("$is_system_module", 1, is_system_module, SafePredFlag);
Yap_InitCPred("new_system_module", 1, new_system_module, SafePredFlag);
Yap_InitCPredBack("$all_current_modules", 1, 1, init_current_module,
cont_current_module, SafePredFlag | SyncPredFlag);
Yap_InitCPredBack("$ground_module", 3, 1, init_ground_module,
cont_ground_module, SafePredFlag | SyncPredFlag);
}
void Yap_InitModules(void) {
CACHE_REGS
LookupSystemModule(MkAtomTerm(AtomProlog));
LOCAL_SourceModule = MkAtomTerm(AtomProlog);
LookupModule(USER_MODULE);
LookupModule(IDB_MODULE);
LookupModule(ATTRIBUTES_MODULE);
LookupSystemModule(CHARSIO_MODULE);
LookupSystemModule(TERMS_MODULE);
LookupSystemModule(SYSTEM_MODULE);
LookupSystemModule(READUTIL_MODULE);
LookupSystemModule(HACKS_MODULE);
LookupModule(ARG_MODULE);
LookupSystemModule(GLOBALS_MODULE);
LookupSystemModule(DBLOAD_MODULE);
LookupSystemModule(RANGE_MODULE);
CurrentModule = PROLOG_MODULE;
}