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compiler: Reject type switch using non-interface type.

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Fixes issue 16.

From-SVN: r190310
This commit is contained in:
Ian Lance Taylor 2012-08-11 04:09:21 +00:00
parent 7380e6efdd
commit 3af76e5a95
1 changed files with 24 additions and 38 deletions
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62
gcc/go/gofrontend/statements.cc
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@ -4192,55 +4192,41 @@ Type_switch_statement::do_lower(Gogo*, Named_object*, Block* enclosing,
? this->var_->var_value()->type()
: this->expr_->type());
if (val_type->interface_type() == NULL)
{
if (!val_type->is_error())
this->report_error(_("cannot type switch on non-interface value"));
return Statement::make_error_statement(loc);
}
// var descriptor_temp DESCRIPTOR_TYPE
Type* descriptor_type = Type::make_type_descriptor_ptr_type();
Temporary_statement* descriptor_temp =
Statement::make_temporary(descriptor_type, NULL, loc);
b->add_statement(descriptor_temp);
if (val_type->interface_type() == NULL)
{
// Doing a type switch on a non-interface type. Should we issue
// a warning for this case?
Expression* lhs = Expression::make_temporary_reference(descriptor_temp,
loc);
Expression* rhs;
if (val_type->is_nil_type())
rhs = Expression::make_nil(loc);
else
{
if (val_type->is_abstract())
val_type = val_type->make_non_abstract_type();
rhs = Expression::make_type_descriptor(val_type, loc);
}
Statement* s = Statement::make_assignment(lhs, rhs, loc);
b->add_statement(s);
}
// descriptor_temp = ifacetype(val_temp) FIXME: This should be
// inlined.
bool is_empty = val_type->interface_type()->is_empty();
Expression* ref;
if (this->var_ == NULL)
ref = this->expr_;
else
{
// descriptor_temp = ifacetype(val_temp)
// FIXME: This should be inlined.
bool is_empty = val_type->interface_type()->is_empty();
Expression* ref;
if (this->var_ == NULL)
ref = this->expr_;
else
ref = Expression::make_var_reference(this->var_, loc);
Expression* call = Runtime::make_call((is_empty
? Runtime::EFACETYPE
: Runtime::IFACETYPE),
loc, 1, ref);
Temporary_reference_expression* lhs =
Expression::make_temporary_reference(descriptor_temp, loc);
lhs->set_is_lvalue();
Statement* s = Statement::make_assignment(lhs, call, loc);
b->add_statement(s);
}
ref = Expression::make_var_reference(this->var_, loc);
Expression* call = Runtime::make_call((is_empty
? Runtime::EFACETYPE
: Runtime::IFACETYPE),
loc, 1, ref);
Temporary_reference_expression* lhs =
Expression::make_temporary_reference(descriptor_temp, loc);
lhs->set_is_lvalue();
Statement* s = Statement::make_assignment(lhs, call, loc);
b->add_statement(s);
if (this->clauses_ != NULL)
this->clauses_->lower(val_type, b, descriptor_temp, this->break_label());
Statement* s = Statement::make_unnamed_label_statement(this->break_label_);
s = Statement::make_unnamed_label_statement(this->break_label_);
b->add_statement(s);
return Statement::make_block_statement(b, loc);