C++里写日志很实用的宏

__FILE__ : 记录当前文件名称（全路径）

__FUNCTION__ : 记录当前函数名称

__LINE__ : 记录当行数

还有很多很实用的宏，如下：最后分享一个本人的日志记录DLL

Macro	Description
__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.

Macro	Description
_ATL_VER	Defines the ATL version.
_CHAR_UNSIGNED	Default char type is unsigned. Defined when /J is specified.
__CLR_VER	Defines the version of the common language runtime used when the application was compiled. The value returned will be in the following format: Mmmbbbbb where, M is the major version of the runtime. mm is the minor version of the runtime. bbbbb is the build number. Copy Code // clr_ver.cpp // compile with: /clr using namespace System; int main() { Console::WriteLine(__CLR_VER); }
__cplusplus_cli	Defined when compiling with /clr, /clr:pure, or /clr:safe. Value of __cplusplus_cli is 200406. __cplusplus_cli is in effect throughout the translation unit. Copy Code // cplusplus_cli.cpp // compile with: /clr #include "stdio.h" int main() { #ifdef __cplusplus_cli printf("%d\n", __cplusplus_cli); #else printf("not defined\n"); #endif }
__COUNTER__	Expands to an integer starting with 0 and incrementing by 1 every time it is used in a compiland. __COUNTER__ remembers its state when using precompiled headers. If the last __COUNTER__ value was 4 after building a precompiled header (PCH), it will start with 5 on each PCH use. __COUNTER__ lets you generate unique variable names. You can use token pasting with a prefix to make a unique name. For example: Copy Code // pre_mac_counter.cpp #include <stdio.h> #define FUNC2(x,y) x##y #define FUNC1(x,y) FUNC2(x,y) #define FUNC(x) FUNC1(x,__COUNTER__) int FUNC(my_unique_prefix); int FUNC(my_unique_prefix); int main() { my_unique_prefix0 = 0; printf_s("\n%d",my_unique_prefix0); my_unique_prefix0++; printf_s("\n%d",my_unique_prefix0); }
__cplusplus	Defined for C++ programs only.
_CPPLIB_VER	Defined if you include any of the C++ Standard Library headers; reports which version of the Dinkumware header files are present.
_CPPRTTI	Defined for code compiled with /GR (Enable Run-Time Type Information).
_CPPUNWIND	Defined for code compiled with /GX (Enable Exception Handling).
_DEBUG	Defined when compiling with /LDd, /MDd, and /MTd.
_DLL	Defined when /MD or /MDd (Multithread DLL) is specified.
__FUNCDNAME__	Valid only within a function and returns the decorated name of the enclosing function (as a string). __FUNCDNAME__ is not expanded if you use the /EP or /P compiler option.
__FUNCSIG__	Valid only within a function and returns the signature of the enclosing function (as a string). __FUNCSIG__ is not expanded if you use the /EP or /P compiler option. On a 64-bit operating system, the calling convention is __cdecl by default.
__FUNCTION__	Valid only within a function and returns the undecorated name of the enclosing function (as a string). __FUNCTION__ is not expanded if you use the /EP or /P compiler option.
_INTEGRAL_MAX_BITS	Reports the maximum size (in bits) for an integral type. Copy Code // integral_max_bits.cpp #include <stdio.h> int main() { printf("%d\n", _INTEGRAL_MAX_BITS); }
_M_ALPHA	Defined for DEC ALPHA platforms (no longer supported).
_M_CEE	Defined for a compilation that uses any form of /clr (/clr:oldSyntax, /clr:safe, for example).
_M_CEE_PURE	Defined for a compilation that uses /clr:pure.
_M_CEE_SAFE	Defined for a compilation that uses /clr:safe.
_M_IX86	Defined for x86 processors. See Values for _M_IX86 for more details.
_M_IA64	Defined for Itanium Processor Family 64-bit processors.
_M_IX86_FP	Expands to a value indicating which /arch compiler option was used: 0 if /arch was not used. 1 if /arch:SSE was used. 2 if /arch:SSE2 was used. See /arch (Minimum CPU Architecture) for more information.
_M_MPPC	Defined for Power Macintosh platforms (no longer supported).
_M_MRX000	Defined for MIPS platforms (no longer supported).
_M_PPC	Defined for PowerPC platforms (no longer supported).
_M_X64	Defined for x64 processors.
_MANAGED	Defined to be 1 when /clr is specified.
_MFC_VER	Defines the MFC version. For example, 0x0700 represents MFC version 7.
_MSC_EXTENSIONS	This macro is defined when compiling with the /Ze compiler option (the default). Its value, when defined, is 1.
_MSC_VER	Reports the major and minor versions of the compiler. For example, 1310 for Microsoft Visual C++ .NET 2003. 1310 represents version 13 and a 1.0 point release. The Visual C++ 2005 compiler version is 1400. Type cl /? at the command line to see the major and minor versions of your compiler along with the build number.
__MSVC_RUNTIME_CHECKS	Defined when one of the /RTC compiler options is specified.
_MT	Defined when /MD or /MDd (Multithreaded DLL) or /MT or /MTd (Multithreaded) is specified.
_NATIVE_WCHAR_T_DEFINED	Defined when /Zc:wchar_t is used.
_OPENMP	Defined when compiling with /openmp, returns an integer representing the date of the OpenMP specification implemented by Visual C++. Copy Code // _OPENMP_dir.cpp // compile with: /openmp #include <stdio.h> int main() { printf("%d\n", _OPENMP); }
_VC_NODEFAULTLIB	Defined when /Zl is used; see /Zl (Omit Default Library Name) for more information.
_WCHAR_T_DEFINED	Defined when /Zc:wchar_t is used or if wchar_t is defined in a system header file included in your project.
_WIN32	Defined for applications for Win32 and Win64. Always defined.
_WIN64	Defined for applications for Win64.
_Wp64	Defined when specifying /Wp64.

As shown in following table, the compiler generates a value for the preprocessor identifiers that reflect the processor option specified.

Option in Development Environment	Command-Line Option	Resulting Value
Blend	/GB	_M_IX86 = 600 (Default. Future compilers will emit a different value to reflect the dominant processor.)
Pentium	/G5	_M_IX86 = 500
Pentium Pro, Pentium II, and Pentium III	/G6	_M_IX86 = 600
80386	/G3	_M_IX86 = 300
80486	/G4	_M_IX86 = 400