Expression *Expression::toDelegate(Scope *sc, Type *t)
{
//printf("Expression::toDelegate(t = %s) %s\n", t->toChars(), toChars());
Type *tw = t->semantic(loc, sc);
Type *tc = t->substWildTo(MODconst)->semantic(loc, sc);
TypeFunction *tf = new TypeFunction(NULL, tc, 0, LINKd);
if (tw != tc) tf->mod = MODwild; // hack for bug7757
(tf = (TypeFunction *)tf->semantic(loc, sc))->next = tw; // hack for bug7757
FuncLiteralDeclaration *fld =
new FuncLiteralDeclaration(loc, loc, tf, TOKdelegate, NULL);
Expression *e;
sc = sc->push();
sc->parent = fld; // set current function to be the delegate
e = this;
e->apply(&lambdaSetParent, sc);
e->apply(&lambdaCheckForNestedRef, sc);
sc = sc->pop();
Statement *s;
if (t->ty == Tvoid)
s = new ExpStatement(loc, e);
else
s = new ReturnStatement(loc, e);
fld->fbody = s;
e = new FuncExp(loc, fld);
e = e->semantic(sc);
return e;
}
/*******************************************
* Look for references to variables in a scope enclosing the new function literal.
*/
int lambdaCheckForNestedRef(Expression *e, void *param)
{
Scope *sc = (Scope *)param;
/* We could use virtual functions instead of a switch,
* but it doesn't seem worth the bother.
*/
switch (e->op)
{
case TOKsymoff:
{ SymOffExp *se = (SymOffExp *)e;
VarDeclaration *v = se->var->isVarDeclaration();
if (v)
v->checkNestedReference(sc, Loc());
break;
}
case TOKvar:
{ VarExp *ve = (VarExp *)e;
VarDeclaration *v = ve->var->isVarDeclaration();
if (v)
v->checkNestedReference(sc, Loc());
break;
}
case TOKthis:
case TOKsuper:
{ ThisExp *te = (ThisExp *)e;
VarDeclaration *v = te->var->isVarDeclaration();
if (v)
v->checkNestedReference(sc, Loc());
break;
}
case TOKdeclaration:
{ DeclarationExp *de = (DeclarationExp *)e;
VarDeclaration *v = de->declaration->isVarDeclaration();
if (v)
{
v->checkNestedReference(sc, Loc());
/* Some expressions cause the frontend to create a temporary.
* For example, structs with cpctors replace the original
* expression e with:
* __cpcttmp = __cpcttmp.cpctor(e);
*
* In this instance, we need to ensure that the original
* expression e does not have any nested references by
* checking the declaration initializer too.
*/
if (v->init && v->init->isExpInitializer())
{ Expression *ie = v->init->toExpression();
ie->apply (&lambdaCheckForNestedRef, param);
}
}
break;
}
default:
break;
}
return 0;
}
