Function expr_free

src/cypher/cypher.c:770–813

/* ── Expression tree helpers ────────────────────────────────────── */

static void expr_free(cbm_expr_t *e) {
    enum { EXPR_FREE_STACK = 128 };
    cbm_expr_t *stack[EXPR_FREE_STACK];
    int top = 0;
    if (e) {
        stack[top++] = e;
    }
    while (top > 0) {
        cbm_expr_t *cur = stack[--top];
        if (cur->type == EXPR_CONDITION) {
            safe_str_free(&cur->cond.variable);
            safe_str_free(&cur->cond.property);
            safe_str_free(&cur->cond.op);
            safe_str_free(&cur->cond.value);
            safe_str_free(&cur->cond.coalesce_default);
            for (int i = 0; i < cur->cond.in_value_count; i++) {
                safe_str_free(&cur->cond.in_values[i]);
            }
            free(cur->cond.in_values);
            safe_str_free(&cur->cond.func);
            for (int i = 0; i < cur->cond.arg_count; i++) {
                safe_str_free(&cur->cond.args[i].variable);
                safe_str_free(&cur->cond.args[i].property);
                safe_str_free(&cur->cond.args[i].literal);
            }
            free(cur->cond.args);
        }
        if (cur->right) {
            if (top < EXPR_FREE_STACK) {
                stack[top++] = cur->right;
            } else {
                expr_free(cur->right); /* recurse when stack overflows */
            }
        }
        if (cur->left) {
            if (top < EXPR_FREE_STACK) {
                stack[top++] = cur->left;
            } else {
                expr_free(cur->left); /* recurse when stack overflows */
            }
        }
        free(cur);
    }
}

static cbm_expr_t *expr_leaf(cbm_condition_t c) {
    cbm_expr_t *e = calloc(CBM_ALLOC_ONE, sizeof(cbm_expr_t));