__PRETTY_FUNCTION__、__FUNCTION__、__func__ 有什么区别? [英] What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?

问题描述

__PRETTY_FUNCTION__、__FUNCTION__、__func__ 之间有什么区别，它们的文档记录在哪里?我如何决定使用哪一个?

What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__, and where are they documented? How do I decide which one to use?

推荐答案

__func__ 是一个隐式声明的标识符，当它在函数内部使用时扩展为包含函数名称的字符数组变量.它在 C99 中被添加到 C 中.来自 C99 §6.4.2.2/1:

__func__ is an implicitly declared identifier that expands to a character array variable containing the function name when it is used inside of a function. It was added to C in C99. From C99 §6.4.2.2/1:

标识符 __func__ 由翻译器隐式声明，就好像紧跟在每个函数定义的左大括号之后，声明

The identifier __func__ is implicitly declared by the translator as if, immediately following the opening brace of each function definition, the declaration

static const char __func__[] = "function-name";

出现，其中 function-name 是词法封闭函数的名称.此名称是函数的朴素名称.

appeared, where function-name is the name of the lexically-enclosing function. This name is the unadorned name of the function.

注意，它不是宏，在预处理过程中没有特殊意义.

Note that it is not a macro and it has no special meaning during preprocessing.

__func__ 在 C++11 中被添加到 C++ 中，其中它被指定为包含一个实现定义的字符串".(C++11 §8.4.1[dcl.fct.def.general]/8)，它不如 C 中的规范有用.(将 __func__ 添加到 C++ 的原始提议是 N1642).

__func__ was added to C++ in C++11, where it is specified as containing "an implementation-defined string" (C++11 §8.4.1[dcl.fct.def.general]/8), which is not quite as useful as the specification in C. (The original proposal to add __func__ to C++ was N1642).

__FUNCTION__ 是一些 C 编译器支持的预标准扩展(包括 gcc 和 Visual C++)；通常，您应该在支持的地方使用 __func__，并且仅在使用不支持它的编译器时才使用 __FUNCTION__(例如，Visual C++，它不支持支持C99，尚不支持所有C++0x，不提供__func__).

__FUNCTION__ is a pre-standard extension that some C compilers support (including gcc and Visual C++); in general, you should use __func__ where it is supported and only use __FUNCTION__ if you are using a compiler that does not support it (for example, Visual C++, which does not support C99 and does not yet support all of C++0x, does not provide __func__).

__PRETTY_FUNCTION__ 是一个 gcc 扩展，与 __FUNCTION__ 基本相同，只是对于 C++ 函数，它包含漂亮"的;函数的名称，包括函数的签名.Visual C++ 有一个类似(但不完全相同)的扩展，__FUNCSIG__.

__PRETTY_FUNCTION__ is a gcc extension that is mostly the same as __FUNCTION__, except that for C++ functions it contains the "pretty" name of the function including the signature of the function. Visual C++ has a similar (but not quite identical) extension, __FUNCSIG__.

对于非标准宏，您需要查阅编译器的文档.Visual C++ 扩展包含在 C++ 编译器 "Predefined Macros" 的 MSDN 文档中.gcc 文档扩展在 gcc 文档页面 "Function Names as Strings" 中进行了描述.;

For the nonstandard macros, you will want to consult your compiler's documentation. The Visual C++ extensions are included in the MSDN documentation of the C++ compiler's "Predefined Macros". The gcc documentation extensions are described in the gcc documentation page "Function Names as Strings."

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