C语言几种 预定义宏

转自： http://blog.sina.com.cn/s/blog_50a0aa5e0100v0x7.html

c的几种可供C语言使用的预定义宏

MSDN 上的解释

__DATE__

The compilation date of the current source file. The date is a string literal of the form Mmm dd yyyy. The month name Mmm is the same as for dates generated by the library function asctime declared in TIME.H.

__FILE__

The name of the current source file. __FILE__ expands to a string surrounded by double quotation marks. To ensure that the full path to the file is displayed, use /FC (Full Path of Source Code File in Diagnostics).

You can create your own wide string version of __FILE__ as follows:

Copy Code

#include <stdio.h>

#define WIDEN2(x) L ## x

#define WIDEN(x) WIDEN2(x)

#define __WFILE__ WIDEN(__FILE__)

wchar_t *pwsz = __WFILE__;

int main() {}

__LINE__

The line number in the current source file. The line number is a decimal integer constant. It can be altered with a #line directive.

__STDC__

Indicates full conformance with the ANSI C standard. Defined as the integer constant 1 only if the /Za compiler option is given and you are not compiling C++ code; otherwise is undefined.

__TIME__

The most recent compilation time of the current source file. The time is a string literal of the form hh:mm:ss.

__TIMESTAMP__

The date and time of the last modification of the current source file, expressed as a string literal in the form Ddd Mmm Date hh:mm:ss yyyy, where Ddd is the abbreviated day of the week and Date is an integer from 1 to 31.

以下是晚上找到的解释

__LINE__ 在源代码中插入当前源代码行号

__FILE__ 在源代码中插入当前源代码文件名

__DATE__ 在源代码中插入当前编译日期〔注意和当前系统日期区别开来〕

__TIME__ 在源代码中插入当前编译时间〔注意和当前系统时间区别开来〕

__STDC__ 当要求程序严格遵循ANSIC标准时该标识符被赋值为1。