DOCUMENT:Q65472 02-MAY-2002 [visualc] TITLE :INFO: Predefined Identifiers in Microsoft C and C++ PRODUCT :Microsoft C Compiler PROD/VER::1.0,1.5,2.0,4.0,5.0,6.0 OPER/SYS: KEYWORDS:kbCompiler kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft C for MS-DOS - Microsoft C for OS/2 - Microsoft C/C++ for MS-DOS - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5 - Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 4.0, 5.0, 6.0 ------------------------------------------------------------------------------- SUMMARY ======= The information below is from the Microsoft C Compiler versions 6.0, 6.0a, and 6.0ax; C/C++ version 7.0; Visual C++ 1.0 and 1.5 for Windows; and Visual C++ 1.0 for Windows NT online Help. The following information can be accessed in C 6.0 and C/C++ 7.0 from the help on CL.EXE by seeking help on the text "cl" using either the F1 key from the Programmer's WorkBench (PWB) or by typing "qh cl" from the MS-DOS or OS/2 command lines. From the "CL Contents" help screen, select Preprocessor Options, then Predefined Identifiers. This information can be accessed in Visual C++ for Windows and Visual C++, 32-bit Edition, by searching on _MSC_VER in the Microsoft C/C++ Language Help. MORE INFORMATION ================ The compiler automatically defines identifiers useful in writing portable programs. You can use these identifiers to compile code sections conditionally. These identifiers are always defined unless otherwise stated. Microsoft Specific ------------------ (NOTE: These macros are supported by both the 16-bit and 32-bit compilers.) Macro Specifies ------------------------------------------------------------------ _CHAR_UNSIGNED Default char type is unsigned. Macro defined when /J is specified. M_I86, _M_I86 Always defined. Identifies target machine as a member of the 8086 family. _MSC_VER Microsoft C version; currently defined as 800. The following symbol was added in C/C++ 7.0: Macro Specifies -------------------------------------------------------------------- __cplusplus Macro defined when compiling a C++ program. (This macro is not defined for the C compiler.) 16-Bit Specific --------------- Macro Specifies ------------------------------------------------------------------- MSDOS, _MSDOS Always defined. Identifies target operating system as MS-DOS. M_I86mM, _M_I86mM Always defined. Member of the I86 processor family. Memory model type: m = T Tiny S Small (default) C Compact model M Medium model L Large model H Huge model Macros defined by /AT, /AS, /AC, /AM, /AL, and /AH respectively. M_I8086, _M_I8086 8088 or 8086 processor; default or defined when /G0 is specified. M_I286, _M_I286 80286 processor. Macro defined when /G1 or /G2 is specified. NO_EXT_KEYS Disables Microsoft-specific language extensions and extended keywords; defined only with /Za option. _QC Supported for compatibility with Microsoft C version 6.0. The _FAST macro (or /f) is the default and is the recommended alternative. The following symbols were added in C/C++ 7.0: Macro Specifies ------------------------------------------------------------------- _DLL Code for run-time library as a dynamic-link library. Defined when /MD is specified. _FAST Fast-Compile. Macro defined when /f is specified Supersedes _QC, which is still supported but not recommended. Using /Od causes CL to compile your program with /f. The /f option compiles source files without any default optimizations. __STDC__ Full conformance with the ANSI C standard. Defined the integer constant 1 only if the /Za command-line option is given; otherwise is undefined. _PCODE Defined for sections of code that are compiled as p-code. Macro defined when /Oq is enabled. _WINDLL Windows protected-mode dynamic-link library is selected with /GD. _WINDOWS Windows protected-mode is selected with /GA, /Gw, /GW, /Mq, or /GD. 32-Bit Specific --------------- The following symbols were added in Visual C++, 32-bit Edition, version 1.0: Macro Specifies ----- --------- _DLL Defined when Multithreaded using DLL (/MD or /MDd) is specified. _M_IX86 Defined as 300 for the 80386 processor (/G3 option), as 400 for the 80486 (/G4) processor, as 500 for the Pentium processor (/G5), and as 600 for Pentium Pro and Pentium II processors (/G6). _MT Defined when Multithreaded (/MD, /MDd, /MT, or /MTd) _WIN32 Defined for WIN32 applications. Always defined. Microsoft specific. The following symbols were added in Visual C++, 32-bit Edition, version 4.0: Macro Specifies ----- --------- _CPPRTTI Defined for code compiled with Enable Run-Time Type Information (/GR). _CPPUNWIND Defined for code compiled with Enable Exception Handling (/GX). The _MSC_VER macro will have one of the following values depending upon the particular Microsoft compiler: Compiler _MSC_VER value -------- -------------- C Compiler version 6.0 600 C/C++ compiler version 7.0 700 Visual C++, Windows, version 1.0 800 Visual C++, 32-bit, version 1.0 800 Visual C++, Windows, version 2.0 900 Visual C++, 32-bit, version 2.x 900 Visual C++, 32-bit, version 4.0 1000 Visual C++, 32-bit, version 5.0 1100 Visual C++, 32-bit, version 6.0 1200 NOTE: If a predefined identifier has two forms, with and without an underscore, the command-line driver defines both if you specify the /Ze option (compile for Microsoft extensions). It defines only the leading underscore form if you specify the /Za option (compile for ANSI compatibility). Additional query words: 8.00 8.00c 9.00 ====================================================================== Keywords : kbCompiler kbVC100 kbVC150 kbVC200 kbVC400 kbVC500 kbVC600 Technology : kbVCsearch kbVC400 kbAudDeveloper kbZNotKeyword8 kbvc150 kbvc100 kbCCompSearch kbZNotKeyword3 kbVC500 kbVC600 kbVC200 kbVC32bitSearch kbVC16bitSearch kbVC500Search Version : :1.0,1.5,2.0,4.0,5.0,6.0 Issue type : kbinfo ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.