bool expr_break(typecheck_t* t, ast_t* ast)
{
if(t->frame->loop_body == NULL)
{
ast_error(ast, "must be in a loop");
return false;
}
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast))
return false;
// break is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_BREAK));
ast_inheritflags(ast);
// Add type to loop.
ast_t* body = ast_child(ast);
if(is_control_type(ast_type(body)))
{
ast_error(body, "break value cannot be a control statement");
return false;
}
ast_t* loop_type = ast_type(t->frame->loop);
loop_type = control_type_add_branch(loop_type, body);
ast_settype(t->frame->loop, loop_type);
return true;
}
bool expr_repeat(pass_opt_t* opt, ast_t* ast)
{
AST_GET_CHILDREN(ast, body, cond, else_clause);
ast_t* body_type = ast_type(body);
ast_t* cond_type = ast_type(cond);
ast_t* else_type = ast_type(else_clause);
if(is_typecheck_error(cond_type))
return false;
if(!is_bool(cond_type))
{
ast_error(opt->check.errors, cond, "condition must be a Bool");
return false;
}
if(is_typecheck_error(body_type) || is_typecheck_error(else_type))
return false;
// All consumes have to be in scope when the loop body finishes.
errorframe_t errorf = NULL;
if(!ast_all_consumes_in_scope(body, body, &errorf))
{
errorframe_report(&errorf, opt->check.errors);
return false;
}
// Union with any existing type due to a break expression.
ast_t* type = ast_type(ast);
// No symbol status is inherited from the loop body or condition. Nothing
// from outside can be consumed, and definitions inside may not occur.
if(!is_control_type(body_type))
type = control_type_add_branch(opt, type, body);
if(!is_control_type(else_type))
{
type = control_type_add_branch(opt, type, else_clause);
ast_inheritbranch(ast, else_clause);
// Use a branch count of two instead of one. This means we will pick up any
// consumes, but not any definitions, since definitions may not occur.
ast_consolidate_branches(ast, 2);
}
if(type == NULL)
type = ast_from(ast, TK_REPEAT);
ast_settype(ast, type);
literal_unify_control(ast, opt);
// Push our symbol status to our parent scope.
ast_inheritstatus(ast_parent(ast), ast);
return true;
}
bool expr_continue(typecheck_t* t, ast_t* ast)
{
if(t->frame->loop_body == NULL)
{
ast_error(ast, "must be in a loop");
return false;
}
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast))
return false;
// continue is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_CONTINUE));
return true;
}
bool expr_break(pass_opt_t* opt, ast_t* ast)
{
typecheck_t* t = &opt->check;
if(t->frame->loop_body == NULL)
{
ast_error(opt->check.errors, ast, "must be in a loop");
return false;
}
errorframe_t errorf = NULL;
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast, &errorf))
{
errorframe_report(&errorf, opt->check.errors);
return false;
}
// break is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_BREAK));
// Add type to loop.
ast_t* body = ast_child(ast);
if(ast_id(body) != TK_NONE)
{
if(is_control_type(ast_type(body)))
{
ast_error(opt->check.errors, body,
"break value cannot be a control statement");
return false;
}
ast_t* loop_type = ast_type(t->frame->loop);
// If there is no body the break will jump to the else branch, whose type
// has already been added to the loop type.
loop_type = control_type_add_branch(opt, loop_type, body);
ast_settype(t->frame->loop, loop_type);
}
return true;
}
bool expr_continue(pass_opt_t* opt, ast_t* ast)
{
typecheck_t* t = &opt->check;
if(t->frame->loop_body == NULL)
{
ast_error(opt->check.errors, ast, "must be in a loop");
return false;
}
errorframe_t errorf = NULL;
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast, &errorf))
{
errorframe_report(&errorf, opt->check.errors);
return false;
}
// continue is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_CONTINUE));
return true;
}