用C DEBUG宏++ [英] DEBUG macros in C++

问题描述

我只是用C遇到了一个DEBUG宏，我真的很喜欢

  #IFDEF DEBUG_BUILD
＃定义DEBUG（X）fprintf中（标准错误，X）
＃其他
＃定义DEBUG（X）做{}而（0）
＃万一
 

我猜一个C ++模拟将是： -

  #IFDEF DEBUG_BUILD
＃定义DEBUG（x）的CERR＆LT;＆LT; X
＃其他
＃定义DEBUG（X）做{}而（0）
＃万一
 

1. 是第二code段类似于一个是C？


2. 你有没有最喜欢的C ++调试宏？

编辑：
通过调试宏我的意思是跑在调试模式的程序而可能会派上用场的宏。

解决方案

是第二code段类似于一个是C？

更多或更少。它的功能更强大，因为你可以包括＆LT;＆LT; 中的参数 - 分隔值，因此用一个参数，你得到的东西，需要一个可变数量的宏参数在C.在另一方面，有一个渺茫的机会，人们会通过在参数分号滥用它。甚至encouter错误是由于调用后一个被遗忘的分号。所以我想这包括在做块：

 将#define DEBUG（X）{做的std :: CERR＆LT;＆LT; X; }而（0）
 

你有没有最喜欢的C ++调试宏？

我喜欢的人上面，而且经常使用它。我无操作通常只是读

 将#define DEBUG（X）
 

具有用于优化编译器相同的效果。虽然低于@Tony D中的评论是corret：这可以留下一些语法错误未被发现

我有时包括运行时检查为好，从而提供某种形式的调试标志的。由于@TonyÐ提醒我，有一个在ENDL往往存在也是有用的。

 将#define DEBUG（X）做{\\
  如果（debugging_enabled）{性病:: CERR＆LT;＆LT;点¯x所述＆;＆下;的std :: ENDL; } \\
}而（0）
 

有时我也在想打印前pression：

 的#define DEBUG2（X）{做的std :: CERR＆LT;＆LT; ＃X＆LT;＆LT; ：＆所述;＆下;点¯x所述＆;＆下;的std :: ENDL; }而（0）
 

在一些宏，我想包括 __ FILE __ ， __ LINE __ 或 __ FUNC __ ，但这些往往断言，而不是简单的调试宏。

I just encountered a DEBUG macro in C that I really like

#ifdef DEBUG_BUILD
#  define DEBUG(x) fprintf(stderr, x)
#else
#  define DEBUG(x) do {} while (0)
#endif

I'm guessing a C++ analogue would be :-

#ifdef DEBUG_BUILD
#  define DEBUG(x) cerr << x
#else
#  define DEBUG(x) do {} while (0)
#endif

1. Is the second code snippet analogous to the one in C?
2. Do you have any favorite C++ debug macros?

EDIT : By "Debug Macros" I mean "macros that might come in handy while running a program in debug mode".

解决方案

Is the second code snippet analogous to the one in C?

More or less. It's is more powerful, as you can include <<-separated values in the argument, so with a single argument you get something that would require a variable number of macro arguments in C. On the other hand, there is a slim chance that people will abuse it by including a semicolon in the argument. Or even encouter mistakes due to a forgotten semicolon after the call. So I'd include this in a do block:

#define DEBUG(x) do { std::cerr << x; } while (0)

Do you have any favorite C++ debug macros?

I like the one above, and use it quite often. My no-op usually just reads

#define DEBUG(x)

which has the same effect for optimizing compilers. Although the comment by @Tony D below is corret: this can leave some syntax errors undetected.

I sometimes include a run-time check as well, thus providing some form of a debug flag. As @Tony D reminded me, having an endl in there is often useful as well.

#define DEBUG(x) do { \
  if (debugging_enabled) { std::cerr << x << std::endl; } \
} while (0)

Sometimes I also want to print the expression:

#define DEBUG2(x) do { std::cerr << #x << ": " << x << std::endl; } while (0)

In some macros, I like to include __FILE__, __LINE__ or __func__, but these are more often assertions and not simple debug macros.

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