DOCUMENT:Q37233 13-NOV-2001 [visualc] TITLE :INFO: Why System Include Files Prototype Functions as _cdecl PRODUCT :Microsoft C Compiler PROD/VER::1.0,1.5,1.51,1.52,2.0,2.1,4.0,5.0,6.0 OPER/SYS: KEYWORDS:kbLangC kbVC100 kbVC150 kbVC151 kbVC152 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft C for MS-DOS - Microsoft C/C++ for MS-DOS - Microsoft Visual C++, versions 1.0, 1.5, 1.51, 1.52, 2.0, 2.1, 4.0 - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 ------------------------------------------------------------------------------- SUMMARY ======= The system include files declare functions that use the C calling and naming conventions with the attribute "cdecl". The compiler uses the C calling and naming conventions by default unless the compiler command line specifies the /Gc or /Gz option switches. The /Gc switch instructs the compiler to use the Pascal (FORTRAN) calling convention by default. The 32-bit compilers do not support the /Gc option switch; they use the /Gz option switch that instructs the compiler to use the __stdcall calling and naming convention by default. The "cdecl" attribute instructs the compiler to generate run-time library calls using the C calling and naming conventions even when the command line specifies the /Gc or /Gz option. Additional query words: ====================================================================== Keywords : kbLangC kbVC100 kbVC150 kbVC151 kbVC152 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600 Technology : kbVCsearch kbVC400 kbAudDeveloper kbZNotKeyword8 kbvc150 kbvc100 kbCCompSearch kbZNotKeyword3 kbVC500 kbVC600 kbVC151 kbVC200 kbVC210 kbVC32bitSearch kbVC152 kbVC500Search Version : :1.0,1.5,1.51,1.52,2.0,2.1,4.0,5.0,6.0 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 2001.