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Q37233: INFO: Why System Include Files Prototype Functions as _cdecl

Article: Q37233
Product(s): Microsoft C Compiler
Version(s): 1.0,1.5,1.51,1.52,2.0,2.1,4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbLangC kbVC100 kbVC150 kbVC151 kbVC152 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600
Last Modified: 13-NOV-2001

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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 
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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:

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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

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