int generateBLOCK(unsigned char * program, int pc, treenode * root)
{
treenode * child = firstchild(root);
while (child != NULL)
{
pc = generate_statement(program, pc, child);
child = nextchild(root, child);
}
return pc;
}
void statement_code_generator::visit(while_tree const &statement)
{
temporary condition_variable(
m_frame,
1
);
auto const at_condition_check = m_emitter.get_current_jump_address();
loop loop(m_frame, m_emitter, at_condition_check);
{
rvalue_generator condition(
m_function_generator,
m_emitter,
m_frame,
condition_variable.address()
);
statement.condition().accept(condition);
}
auto const at_skip_body = m_emitter.get_current_jump_address();
m_emitter.jump_if_not(
-1,
condition_variable.address().local_address()
);
generate_statement(
statement.body(),
m_function_generator,
m_emitter,
m_frame
);
m_emitter.jump(at_condition_check);
auto const at_after_loop = m_emitter.get_current_jump_address();
m_emitter.update_jump_destination(
at_skip_body,
at_after_loop);
loop.finish(at_after_loop);
}
void statement_code_generator::visit(block_tree const &statement)
{
local_frame block_symbols(m_frame);
for (auto s = begin(statement.body()); s != end(statement.body()); ++s)
{
try
{
generate_statement(
**s,
m_function_generator,
m_emitter,
block_symbols
);
}
catch (compiler_error const &e)
{
m_function_generator.handle_error(e);
}
}
}
void statement_code_generator::visit(if_tree const &statement)
{
//TODO: only create a variable if needed
temporary const condition_variable(
m_frame,
1
);
{
rvalue_generator condition(
m_function_generator,
m_emitter,
m_frame,
condition_variable.address()
);
statement.condition().accept(condition);
}
auto const jump_if_address = m_emitter.get_current_jump_address();
m_emitter.jump_if_not(
-1,
condition_variable.address().local_address()
);
generate_statement(
statement.on_true(),
m_function_generator,
m_emitter,
m_frame
);
auto const * const on_false = statement.on_false();
auto const skip_else_address = m_emitter.get_current_jump_address();
if (on_false)
{
m_emitter.jump(
-1
);
}
m_emitter.update_jump_destination(
jump_if_address,
m_emitter.get_current_jump_address()
);
if (on_false)
{
generate_statement(
*on_false,
m_function_generator,
m_emitter,
m_frame
);
m_emitter.update_jump_destination(
skip_else_address,
m_emitter.get_current_jump_address()
);
}
}