DOCUMENT:Q228455 07-MAY-2001 [visualc] TITLE :PRB: Missing /c Compiler Option Causes LNK1561 Linker Error PRODUCT :Microsoft C Compiler PROD/VER:winnt:6.0 OPER/SYS: KEYWORDS:kbCompiler kbLinker kbVC600 ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 - Microsoft Visual C++, 32-bit Professional Edition, version 6.0 - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When compiling a multiple source file project that creates a pre-compiled header file inside the Visual C++ Integrated Development Environment (IDE), the following error can occur: Compiling... StdAfx.cpp LINK : fatal error LNK1561: entry point must be defined Error executing cl.exe. NOTE: The linker error is generated during the compiler phase of the build. CAUSE ===== The /c compiler option is missing from the build settings. RESOLUTION ========== Add /c to the compiler options. To do this, you must edit the compiler options in the Project Options box in the C/C++ tab under Project Settings. NOTE: This box is only editable if the whole project is selected in the tree control on the Project Settings. STATUS ====== This behavior is by design. MORE INFORMATION ================ By default, the Visual C/C++ compiler attempts to compile and link in a single step. The /c (Compile without Linking) option is used to tell the compiler to compile only. Since Visual C++ compiles and links in separate steps, then /c is required for all Visual C++ builds. To reproduce the error, create a default MFC project and remove the /c option from the Project Settings by editing the compiler options in the Project Options box in the C/C++ tab under Project Settings. REFERENCES ========== (c) Microsoft Corporation 1999, All Rights Reserved. Contributions by Kelly Marie Ward, Microsoft Corporation Additional query words: ====================================================================== Keywords : kbCompiler kbLinker kbVC600 Technology : kbVCsearch kbAudDeveloper kbVC600 kbVC32bitSearch Version : winnt:6.0 Issue type : kbprb ============================================================================= 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.