TypeSpec
ASTreturn_statement::typecheck (TypeSpec expected)
{
FunctionSymbol *myfunc = oslcompiler->current_function ();
if (myfunc) {
// If it's a user function (as opposed to a main shader body)...
if (expr()) {
// If we are returning a value, it must be assignable to the
// kind of type the function actually returns. This check
// will also catch returning a value from a void function.
TypeSpec et = expr()->typecheck (myfunc->typespec());
if (! assignable (myfunc->typespec(), et)) {
error ("Cannot return a '%s' from '%s %s()'",
type_c_str(et), type_c_str(myfunc->typespec()),
myfunc->name().c_str());
}
} else {
// If we are not returning a value, it must be a void function.
if (! myfunc->typespec().is_void ())
error ("You must return a '%s' from function '%s'",
type_c_str(myfunc->typespec()),
myfunc->name().c_str());
}
// If the function has other statements AFTER 'return', or if
// the return statement is in a conditional, we'll need to
// handle it specially when generating code.
myfunc->complex_return (this->nextptr() != NULL ||
myfunc->nesting_level() > 0);
} else {
// We're not part of any user function, so this 'return' must
// be from the main shader body. That's fine (it's equivalent
// to calling exit()), but it can't return a value.
if (expr())
error ("Cannot return a value from a shader body");
}
return TypeSpec(); // TODO: what should be returned here?
}
void
SemanticAnalysis::visitNameProxy(NameProxy *proxy)
{
Symbol *binding = proxy->sym();
switch (binding->kind()) {
case Symbol::kType:
cc_.report(proxy->loc(), rmsg::cannot_use_type_as_value)
<< binding->asType()->type();
break;
case Symbol::kConstant:
{
ConstantSymbol *sym = binding->toConstant();
proxy->setOutput(sym->type(), VK::rvalue);
break;
}
case Symbol::kFunction:
{
FunctionSymbol *sym = binding->toFunction();
FunctionStatement *decl = sym->impl();
if (!decl) {
cc_.report(proxy->loc(), rmsg::function_has_no_impl)
<< sym->name();
break;
}
if (!decl->type())
decl->setType(FunctionType::New(decl->signature()));
// Function symbols are clvalues, since they are named.
// :TODO:
proxy->setOutput(decl->type(), VK::lvalue);
break;
}
default:
assert(false);
}
}