Function build_perl_nested_calls

tests/repro/repro_issue471.c:119–155

 * would trip -Werror=unused-function. */
static char *build_perl_nested_calls(int depth) __attribute__((unused));
static char *build_perl_nested_calls(int depth) {
    /*
     * Header:        "sub f { return $_[0]; }\nmy $x = "   (~32 bytes)
     * Per open:      "f("                                   (2 bytes each)
     * Inner literal: "1"                                    (1 byte)
     * Per close:     ")"                                    (1 byte each)
     * Trailer:       ";\n"                                  (2 bytes)
     * Null:          1 byte
     *
     * Total upper bound: 40 + depth*2 + 1 + depth + 3 = depth*3 + 44
     */
    size_t sz = (size_t)depth * 3 + 64;
    char *buf = (char *)malloc(sz);
    if (!buf) return NULL;

    char *p = buf;
    p += snprintf(p, sz, "sub f { return $_[0]; }\nmy $x = ");

    /* NESTING_DEPTH levels of `f(` */
    for (int i = 0; i < depth; i++) {
        *p++ = 'f';
        *p++ = '(';
    }

    /* innermost literal */
    *p++ = '1';

    /* matching closing parens */
    for (int i = 0; i < depth; i++) {
        *p++ = ')';
    }

    /* statement terminator */
    p += snprintf(p, (size_t)(buf + sz - p), ";\n");

    return buf;
}

/*
 * repro_issue471_glr_nested_ambiguity_terminates