仍然可以通过puts和printf到达 [英] Still reachable with puts and printf

问题描述

Valgrind报告了在诸如printf和puts之类的函数上仍然可以解决的错误".我真的不知道该怎么办.我需要摆脱它，因为它是一个学校项目，并且完全没有错误.我该如何处理?从报告中我可以看到那些函数使用malloc，但是我一直认为它们是自己处理内存的，对吗? 我使用的是Mac OS X，也许这是valgrind和OS之间的问题?

Valgrind is reporting the still reachable "error" on functions like printf and puts. I really don't know what to do about this. I need to get rid of it since it's a school project and there has to be no errors at all. How do I deal with this? From the report I can see those functions use malloc, but I always thought they handled the memory by themselves, right? I'm using mac OS X so maybe it's a problem between valgrind and the OS?

示例代码:使用的任何puts或printf上都会出现错误

SAMPLE CODE: The error appears on any of the puts or printf that are used

void twittear(array_t* array_tweets, hash_t* hash, queue_t* queue_input){

    char* user = queue_see_first(queue_input);
    char key[1] = "@";

    if (!user || user[0] != key[0]) {
        puts("ERROR_WRONG_COMAND");
        return;
    }

    queue_t* queue_keys = queue_create();
    char* text = join_text(queue_input, queue_keys);

    if (!text) {
        puts("ERROR_TWEET_TOO_LONG");
            queue_destroy(queue_keys, NULL);
        return;
    }

    int id = new_tweet(array_tweets, text);
    while (!queue_is_empty(queue_keys))
        hash_tweet(hash, queue_dequeue(queue_keys), id);
    queue_destroy(queue_keys, NULL);
    printf("OK %d\n", id);
}

错误:

==1954== 16,384 bytes in 1 blocks are still reachable in loss record 77 of 77
==1954==    at 0x47E1: malloc (vg_replace_malloc.c:300)
==1954==    by 0x183855: __smakebuf (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x198217: __swsetup (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x1B1158: __v2printf (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x1B16AF: __xvprintf (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x188B29: vfprintf_l (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x18696F: printf (in /usr/lib/system/libsystem_c.dylib)
==1954==    by 0x1000036F3: twittear (main.c:138)
==1954==    by 0x100003C8D: main (main.c:309

推荐答案

在Mac OS X上，Valgrind有点小故障.它没有完全禁止某些系统库. (也就是说，它不会适当地忽略某些预期的"泄漏.)结果通常会包含诸如此类的虚假结果，以及由于优化memcpy()之类的功能而导致的某些缓冲区溢出.

Valgrind is somewhat glitchy on Mac OS X; it doesn't have complete suppressions for some system libraries. (That is, it doesn't properly ignore some "expected" leaks.) Results will frequently include some spurious results like this, as well as some buffer overruns resulting from optimizations in functions like memcpy().

我的建议?除非您非常熟悉该工具，否则请避免在Mac OS X上使用valgrind.在Linux系统上编译和测试您的应用程序以获得最佳结果.

My advice? Avoid using valgrind on Mac OS X unless you are very familiar with the tool. Compile and test your application on a Linux system for best results.

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