Gcc 为什么在使用optmization编译时会收到此警告？

警告：在解析对函数“help”的调用时，参数被丢弃

如果我使用
gcc-O3 codice-o out/codice进行编译，我会得到这个讨厌的警告。它完成了编译，所以我只是想知道为什么会发生这种情况

我在安装了xcode 4.3的mac on lion上。它使用的编译器是
i686-apple-darwin11-llvm-gcc-4.2

请注意，如果我将
-O3
切换到-O2/-O1/-O，则它将继续发出相同的警告

代码如下

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <math.h>

void help();

char *codice_encrypt(char *in);
char *codice_decrypt(char *in);

void sigint_handler(int signal) {
    exit(2);
}

int main (int argc, char **argv) {

    if (argc != 3) {
        help();
    }

    signal(SIGINT, sigint_handler);
    char *ret, *status;
    int tmpret;

    if (strcmp(argv[1], "e") == 0 || strcmp(argv[1], "encrypt") == 0) {
        status = "Encrypting...\n";
        tmpret = write(STDOUT_FILENO, status, strlen((const char *)status));
        ret = codice_encrypt(argv[2]);
    } else if (strcmp(argv[1], "d") == 0 || strcmp(argv[1], "decrypt") == 0) {
        status = "Decrypting...\n";
        tmpret = write(STDOUT_FILENO, status, strlen((const char *)status));
        ret = codice_decrypt(argv[2]);
    } else {
        status = "Could not understand command line arguments O.o\n";
        tmpret = write(STDOUT_FILENO, status, strlen((const char *)status));
        help(STDOUT_FILENO);
    }

    status = "Success!\nRetval:\n\n";
    tmpret = write(STDOUT_FILENO, status, strlen((const char *)status));
    tmpret = write(STDOUT_FILENO, ret, strlen((const char *)ret));
    tmpret = write(STDOUT_FILENO, "\n\n", 2);

    return 0;

}

void help() {
    int tmpret;
    const char *logo = "\n\n\t\tooooooo__oo______________________\n"
                 "\t\t_____oo______oo_oo_oo__oo_oo_oo__\n"
                 "\t\t____oo___oo__ooo_oo__o_ooo_oo__o_\n"
                 "\t\t___o_____oo__oo__oo__o_oo__oo__o_\n"
                 "\t\t_oo______oo__oo__oo__o_oo__oo__o_\n"
                 "\t\tooooooo_oooo_oo______o_oo______o_\n"
                 "\t\t_________________________________\n\n\n";
    tmpret = write(STDOUT_FILENO, logo, strlen(logo));
    const char *help = "Help\n"
                       "Is\n"
                       "Still\n"
                       "Being\n"
                       "Written :)\n\n";
    tmpret = write(STDOUT_FILENO, help, strlen(help));
    exit(1);
}

char *codice_encrypt(char *in) {
    unsigned int i;
    char ya = 0x55;
    write(STDOUT_FILENO, "0x", 2);
    char itret[50];
    sprintf(itret,"%#hhx",ya);
    write(STDOUT_FILENO, itret, strlen(itret));
    write(STDOUT_FILENO, "\n", 1);
    ya = ya & 0x0F;
    ya = ya >> 1;
    sprintf(itret,"%#hhx",ya);
    write(STDOUT_FILENO, itret, strlen(itret));
    write(STDOUT_FILENO, "\n", 1);
    ya = 0x55;
    ya = ya & 0xF0;
    ya = ya << 1;
    sprintf(itret,"%#hhx",ya);
    write(STDOUT_FILENO, itret, strlen(itret));
    write(STDOUT_FILENO, "\n", 1);
    return in;
}

char *codice_decrypt(char *in) {
    return in;
}

#包括
#包括
#包括
#包括
#包括
#包括
#包括
无效帮助（）；
字符*密码加密（字符*输入）；
char*codice_解密（char*in）；
无效信号处理器（内部信号）{
出口（2）；
}
int main（int argc，字符**argv）{
如果（argc！=3）{
帮助（）；
}
信号（SIGINT，SIGINT_处理器）；
字符*ret，*状态；
int tmpret；
如果（strcmp（argv[1]，“e”）==0 | | strcmp（argv[1]，“encrypt”）==0）{
status=“正在加密…\n”；
tmpret=write（STDOUT_文件号，状态，strlen（（const char*）状态））；
ret=密码加密（argv[2]）；
}else if（strcmp（argv[1]，“d”）==0 | | strcmp（argv[1]，“decrypt”）==0）{
status=“正在解密…\n”；
tmpret=write（STDOUT_文件号，状态，strlen（（const char*）状态））；
ret=codice_decrypt（argv[2]）；
}否则{
status=“无法理解命令行参数O.O\n”；
tmpret=write（STDOUT_文件号，状态，strlen（（const char*）状态））；
帮助（标准文件号）；
}
status=“Success！\nRetval:\n\n”；
tmpret=write（STDOUT_文件号，状态，strlen（（const char*）状态））；
tmpret=write（STDOUT_FILENO，ret，strlen（（const char*）ret））；
tmpret=write（标准输出文件号“\n\n”，2）；
返回0；
}
无效帮助（）{
int tmpret；
const char*logo=“\n\n\t\tooooooooooo\uoooooo\uoooo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uoo\uuoo\uoo\uuoo\uu
“\t\t\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
“\t\t\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu\n”
“\t\t\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu\n”
“\t\t\u oo\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
“\t\toooooooooooooooooooo\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
“\t\t\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu\n\n”；
tmpret=write（标准文件号、标志、标准格式（标志））；
const char*help=“help\n”
“是\n”
“仍然\n”
“正在\n”
“书面：）\n\n”；
tmpret=write（STDOUT_FILENO，help，strlen（help））；
出口（1）；
}
字符*密码加密（字符*输入）{
无符号整数i；
char ya=0x55；
写入（标准输出文件号，“0x”，2）；
char-itret[50]；
sprintf（itret，“%#hhx”，ya）；
写入（STDOUT_文件号、itret、strlen（itret））；
写入（标准输出文件号，“\n”，1）；
ya=ya&0x0F；
ya=ya>>1；
sprintf（itret，“%#hhx”，ya）；
写入（STDOUT_文件号、itret、strlen（itret））；
写入（标准输出文件号，“\n”，1）；
ya=0x55；
ya=ya&0xF0；
ya=ya此处help（）的参数数量可变（我假设我们讨论的是C代码）。但是，没有传递任何参数，也没有读取任何参数。其中一个优化过程意识到了这一点，并发出了这样的警告。将help（）定义为help（void）将解决此问题。
您正在将
STDOUT\u FILENO
传递给
help（）
它的定义中没有参数吗？那只是一种类型，我删除了它。很抱歉说得含糊不清，谢谢你是一个好的解释器：D有没有一个术语，让我可以在谷歌上搜索一下，看看为什么会是这样？谢谢！