调试利用内存并释放内存的宏？

发布于 2024-10-24 23:08:38 字数 957 浏览 5 评论 0原文

我编写了一个调试宏，并希望在其中包含时间，在本例中，我的函数 gettimestr() 接受一个小缓冲区（长度始终为 8，因为它的 sprintf填充到 00:00:00）并将其包含在 fprintf 中。我的宏如下所示：

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
          char timebufstr_0[8]; \
          gettimestr( timebufstr_0 );\
          _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__)
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

我的第一次尝试是让 gettimestr 返回一个 const char*，但这很难释放内存，所以我继续使用缓冲区如果你能看到的话。

不幸的是，缓冲区不能使用两次（两个 DEBUGPRINT 将给出重新声明错误），而且我相信它不会释放内存，因为当 main 返回时它会消失，因为它不在函数中？

我的问题是：

我应该 malloc() 8 个字节（或者 9 个字节，如果对于 \0，我不知道这是否是现在需要）而不是[8]，这样我就可以在堆中按需释放它？
我应该如何创建缓冲、销毁引用和重用它在另一个宏调用中修复我的我无法调用它的问题两次？

原文

I have written a debugging macro and wished to include the time in it, in this case my function gettimestr() accepts a small buffer (always 8 in length, because its sprintf pads to 00:00:00) and include that with the fprintf within. My macro looks like the following:

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
          char timebufstr_0[8]; \
          gettimestr( timebufstr_0 );\
          _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__)
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

My first attempt was to have gettimestr return a const char*, but that is hard to free memory of so I went ahead and used a buffer if you can see.

Unfortunately the buffer cannot be used twice (two DEBUGPRINTs will give a redeclaration error) and also I believe it won't free the memory because it will disappear when main returns, as it is not in a function?

My questions are:

Should I malloc() 8 bytes (or 9 if
for \0, I am unaware if that is
required now) instead of [8] so I can
free it on demand in the heap?
How should I be able to create the
buffer, destroy references, and reuse
it in another macro call to fix my
problem where I could not call it
twice?

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倥絔 2024-10-31 23:08:38

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
   do { \
      char timebufstr_0[8]; \
      gettimestr( timebufstr_0 );\
      _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__) \
   } while (0);
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

将允许多次使用并在每次使用后释放缓冲区。

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
   do { \
      char timebufstr_0[8]; \
      gettimestr( timebufstr_0 );\
      _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__) \
   } while (0);
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

Will allow multiple uses and deallocate the buffer after each use.

回复收藏 0 原文

旧街凉风 2024-10-31 23:08:38

您应该分配 9 个字节来包含 '\0' 字节。最好的方法是通过代码中发布的数组来实现。为了克服双重定义的问题，您可以将其括在 {} 中，例如：

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
          {\ // <---------
          char timebufstr_0[9]; \
          gettimestr( timebufstr_0 );\
          _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__)\
          } // <---------
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

You should allocate 9 bytes for including the '\0' byte. The best way is to make it via a an array as posted in your code. For overcomming the problems of double-definition, you can enclose it in {}, e.g.:

#define _DEBUGPRINT(...)    fprintf(stderr, __VA_ARGS__);
#ifndef NDEBUG
#  define WHERESTR  "[[%s] file %s, line %d]: "
#  define WHEREARG  timebufstr_0, __FILE__, __LINE__
#  define DEBUGPRINT(_fmt, ...) \
          {\ // <---------
          char timebufstr_0[9]; \
          gettimestr( timebufstr_0 );\
          _DEBUGPRINT(WHERESTR _fmt, WHEREARG, __VA_ARGS__)\
          } // <---------
#else
#  define DEBUGPRINT(_fmt, ...)  /**/
#endif

回复收藏 0 原文

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