c/c++预定义宏

Names the predefined ANSI C and Microsoft
C++ implementation macros.

The compiler recognizes predefined ANSI C macros and the Microsoft C++
implementation provides several more. These macros take no arguments and cannot
be redefined. Some of the predefined macros listed below are defined with
multiple values. See the following tables for more information.

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