PRB: Missing /c Compiler Option Causes LNK1561 Linker Error

• Microsoft Visual C++, 32-bit Editions, 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.

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

© Microsoft Corporation 1999, All Rights Reserved.
Contributions by Kelly Marie Ward, Microsoft Corporation

Additional query words:

Keywords : kbCompiler kbLinker kbVC600
Version : winnt:6.0
Platform : winnt
Issue type : kbprb