copy_expression
struct expression *unop = copy_expression(expr->unop);
struct expression *base = copy_expression(expr->base);
struct expression *left = copy_expression(expr->left);
struct expression *right = copy_expression(expr->right);
struct expression *left = copy_expression(expr->left);
struct expression *right = copy_expression(expr->right);
struct expression *deref = copy_expression(expr->deref);
expr->cast_expression = copy_expression(cast);
struct expression *cast = copy_expression(expr->cast_expression);
struct expression *cond = copy_expression(expr->conditional);
struct expression *valt = copy_expression(expr->cond_true);
struct expression *valf = copy_expression(expr->cond_false);
struct expression *fn = copy_expression(expr->fn);
add_expression(&expr->args, copy_expression(arg));
add_expression(&expr->expr_list, copy_expression(entry));
struct expression *sub_expr = copy_expression(expr->idx_expression);
struct expression *sub_expr = copy_expression(expr->ident_expression);
struct expression *val = copy_expression(expr->init_expr);
struct expression *val = copy_expression(expr->down);
struct expression *idx = copy_expression(expr->index);
expr->constraint = copy_expression(expr->constraint);
expr->expr = copy_expression(expr->expr);
add_expression(&out, copy_expression(expr));
newsym->initializer = copy_expression(sym->initializer);
struct expression *expr = copy_expression(stmt->expression);
struct expression *expr = copy_expression(stmt->range_expression);
cond = copy_expression(cond);
struct expression *retval = copy_expression(stmt->ret_value);
stmt->case_expression = copy_expression(stmt->case_expression);
stmt->case_to = copy_expression(stmt->case_to);
struct expression *expr = copy_expression(stmt->switch_expression);
stmt->iterator_pre_condition = copy_expression(stmt->iterator_pre_condition);
stmt->iterator_post_condition = copy_expression(stmt->iterator_post_condition);
stmt->goto_expression = copy_expression(stmt->goto_expression);