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/*****
* env.cc
* Andy Hammerlindl 2002/6/20
*
* Keeps track of the namespaces of variables and types when traversing
* the abstract syntax.
*****/
#include "env.h"
#include "record.h"
#include "genv.h"
#include "builtin.h"
using namespace types;
namespace trans {
// Instances of this class are passed to types::ty objects so that they can call
// back to env when checking casting of subtypes.
class envCaster : public caster {
protoenv &e;
symbol name;
public:
envCaster(protoenv &e, symbol name)
: e(e), name(name) {}
access *operator() (ty *target, ty *source) {
return e.lookupCast(target, source, name);
}
bool castable(ty *target, ty *source) {
return e.castable(target, source, name);
}
};
access *protoenv::baseLookupCast(ty *target, ty *source, symbol name) {
static identAccess id;
assert(target->kind != ty_overloaded &&
source->kind != ty_overloaded);
// If errors already exist, don't report more. This may, however, cause
// problems with resoving the signature of an overloaded function. The
// abstract syntax should check if any of the parameters had an error before
// finding the signature.
if (target->kind == ty_error || source->kind == ty_error)
return &id;
else if (equivalent(target,source))
return &id;
else {
varEntry *v=lookupVarByType(name,new function(target,source));
return v ? v->getLocation() : 0;
}
}
access *protoenv::lookupCast(ty *target, ty *source, symbol name) {
access *a=baseLookupCast(target, source, name);
if (a)
return a;
envCaster ec(*this, name);
return source->castTo(target, ec);
}
bool protoenv::castable(ty *target, ty *source, symbol name) {
struct castTester : public tester {
protoenv &e;
symbol name;
castTester(protoenv &e, symbol name)
: e(e), name(name) {}
bool base(ty *t, ty *s) {
access *a=e.baseLookupCast(t, s, name);
if (a)
return true;
envCaster ec(e, name);
return s->castable(t, ec);
}
};
castTester ct(*this, name);
return ct.test(target,source);
}
bool protoenv::fastCastable(ty *target, ty *source) {
assert(target->kind != types::ty_overloaded);
assert(target->kind != types::ty_error);
assert(source->kind != types::ty_error);
// To avoid memory allocation, fill one static variable with new parameters
// in each call.
// Warning: This is not re-entrant if asy ever goes multi-threaded.
static types::function castFunc(primVoid(), primVoid());
castFunc.result = target;
if (source->kind == types::ty_overloaded) {
bool result = false;
types::ty_vector& v = ((overloaded *)source)->sub;
for (size_t i = 0; i < v.size(); ++i) {
castFunc.sig.formals[0].t = v[i];
if (lookupVarByType(symbol::castsym, &castFunc)) {
result = true;
break;
}
}
//assert(result == castable(target, source, symbol::castsym));
//cout << "fc OVERLOADED " << (result ? "CAST" : "FAIL") << endl;
return result;
}
//else cout << "fc SIMPLE" << endl;
// Don't test for equivalent, as that is already done by the castScore
// code. Assert disabled for speed.
#if 0
assert(!equivalent(target, source));
#endif
castFunc.sig.formals[0].t = source;
if (lookupVarByType(symbol::castsym, &castFunc))
return true;
// Test for generic casts of null. This should be moved to a types.h
// routine.
return source->kind == ty_null && target->isReference();
}
access *protoenv::fastLookupCast(ty *target, ty *source) {
assert(target->kind != types::ty_overloaded);
assert(target->kind != types::ty_error);
assert(source->kind != types::ty_overloaded);
assert(source->kind != types::ty_error);
// Warning: This is not re-entrant.
static types::function castFunc(primVoid(), primVoid());
castFunc.result = target;
castFunc.sig.formals[0].t = source;
varEntry *ve = lookupVarByType(symbol::castsym, &castFunc);
if (ve)
return ve->getLocation();
// Fall back on slow routine.
return lookupCast(target, source, symbol::castsym);
}
ty *protoenv::castTarget(ty *target, ty *source, symbol name) {
struct resolver : public collector {
protoenv &e;
symbol name;
resolver(protoenv &e, symbol name)
: e(e), name(name) {}
types::ty *base(types::ty *target, types::ty *source) {
return e.castable(target, source, name) ? target : 0;
}
};
resolver r(*this, name);
return r.collect(target, source);
}
ty *protoenv::castSource(ty *target, ty *source, symbol name) {
struct resolver : public collector {
protoenv &e;
symbol name;
resolver(protoenv &e, symbol name)
: e(e), name(name) {}
types::ty *base(types::ty *target, types::ty *source) {
return e.castable(target, source, name) ? source : 0;
}
};
resolver r(*this, name);
return r.collect(target, source);
}
void protoenv::addArrayOps(array *a)
{
trans::addArrayOps(ve, a);
}
void protoenv::addRecordOps(record *r)
{
trans::addRecordOps(ve, r);
}
void protoenv::addFunctionOps(function *f)
{
trans::addFunctionOps(ve, f);
}
env::env(genv &ge)
: protoenv(venv::file_env_tag()), ge(ge)
{
// NOTE: May want to make this initial environment into a "builtin" module,
// and then import the builtin module.
base_tenv(te);
base_venv(ve);
}
env::~env()
{
}
record *env::getModule(symbol id, string filename)
{
return ge.getModule(id, filename);
}
}
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