c，控制到达c中非void函数的末尾

发布于 2024-11-28 19:49:59 字数 734 浏览 1 评论 0原文

我有以下代码中的 dispatchQueue.c:215: warning: controlreached end of non-void function 警告..
谁能解释一下为什么吗？

void *dispatcher_threadloop(void *arg){

//thread loop of the dispatch thread- pass the tast to one of worker thread

dispatch_queue_thread_t *dThread = arg;
dispatch_queue_t *dQueue;
dQueue = dThread->queue;

if (dQueue->HEAD!=NULL){
    for(;;){
        printf("test");
        sem_wait(&(dQueue->queue_task_semaphore));
        dThread->current_task = dQueue->HEAD;
        dQueue->HEAD =  dQueue->HEAD->next;
        dQueue->HEAD->prev = NULL;
        sem_post(&(dQueue->queue_task_semaphore));
        break;
        //TODO
    }
}

}

原文

I have dispatchQueue.c:215: warning: control reaches end of non-void function warning from the code below..
Can anyone please explain why?

void *dispatcher_threadloop(void *arg){

//thread loop of the dispatch thread- pass the tast to one of worker thread

dispatch_queue_thread_t *dThread = arg;
dispatch_queue_t *dQueue;
dQueue = dThread->queue;

if (dQueue->HEAD!=NULL){
    for(;;){
        printf("test");
        sem_wait(&(dQueue->queue_task_semaphore));
        dThread->current_task = dQueue->HEAD;
        dQueue->HEAD =  dQueue->HEAD->next;
        dQueue->HEAD->prev = NULL;
        sem_post(&(dQueue->queue_task_semaphore));
        break;
        //TODO
    }
}

}

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寄意 2024-12-05 19:49:59

因为您声明它 void * （不是 void）并且不返回任何内容。如果不需要任何返回值，则返回NULL。

void *dispatcher_threadloop(void *arg)

Because you are declaring it void * (not void) and not returning anything. Return NULL if you don’t need any return value.

void *dispatcher_threadloop(void *arg)

回复收藏 0 原文

各自安好 2024-12-05 19:49:59

好吧，想象一下如果 dQueue->HEAD 为 NULL 会发生什么：if 不会被输入，所以你会到达结尾该函数应该返回一个 void* - 但你不返回任何东西。

尝试在函数底部返回一些合理的值来解决此问题。或者添加一个断言，声明此代码应该无法访问，例如：

assert( !"Unreachable code hit" );

Well, imagine what happens if dQueue->HEAD is NULL: the if won't be entered, so you get to the end of the function which is supposed to return a void* - but you don't return anything.

Try returning some sensible value at the bottom of your function to fix this. Or add an assertion which states that this code should be unreachable, like: