I get the error message "LINK: error LNK2001: unresolved external symbol _WinMainCRTStartup"

Question

Please, help. In Visual Studio 2008, I get the following errors.

============================================================ 1>Microsoft (R) Windows Resource To Object Converter Version 9.00.30729.01 1>Copyright (C) Microsoft Corporation. All rights reserved. 1>adding resource. type:ICON, name:1, language:0x0409, flags:0x1010, size:744 1>adding resource. type:ICON, name:2, language:0x0409, flags:0x1010, size:296 1>adding resource. type:GROUP_ICON, name:128, language:0x0409, flags:0x1030, size:34 1>adding resource. type:DIALOG, name:100, language:0x0409, flags:0x1030, size:374 1>adding resource. type:DIALOG, name:102, language:0x0409, flags:0x1030, size:784 1>adding resource. type:VERSION, name:1, language:0x0409, flags:0x30, size:928 1>adding resource. type:STRING, name:7, language:0x0409, flags:0x1030, size:68 1>LINK : error LNK2001: unresolved external symbol _WinMainCRTStartup 1>.\Release/DiskTest.exe : fatal error LNK1120: 1 unresolved externals 1>Build log was saved at "file://c:\WinIRDir\Utilities\DiskTest\Release\BuildLog.htm" 1>DiskTest - 2 error(s), 0 warning(s) 1>Build log was saved at "file://c:\WinIRDir\Utilities\CommApp\Release\BuildLog.htm" ============================================================== 

Here is the situation. - DiskTest.exe is one of three projects in my solution - This project is perfect for Debug x64, Release x64 and Debug Win32. Release Win32 is the only one that generates these errors. - I spend hours comparing property pages for all 4 configuration / machine configurations, and I'm sure that no properties are missing from one version to another. I paid special attention to "Additional Dependencies", "Additional Library Directories", "Login", etc. Of course, .lib file paths point to \ Debug or \ Release and \ x86 or \ x64 for the appropriate configuration or platform.

The only "additional dependency" of this project is SBF_Util.lib and SBF_Utild.lib for Debug. I was convinced that all 4 versions (debug win32 and x64 and Release win32 and x64) of this library exist in the folder specified in each "additional library directory". I also checked dumpbin on each version of the library to make sure the platform is consistent.

I saw other situations in which there is no main entry point, but in this case all other versions arise without problems, only the Win32 Relase version generates this error, so I don’t think I need to change anything in the code.

Can anyone give any clues ?, I have no ideas. Any ideas would be greatly appreciated. Thanks.

Answer 1

INCREDIBLE !!!

I found a problem! It was an incredibly simple thing that caused this crypto error: “SPACE”

It turns out that under Configuration-> C / C ++ → OutputFiles-> Object File Name: I had: "$ (IntDir) \"

I did not notice the place until I paid very close attention to the Kdiff3 window, and noticed this little underline to signal a space. This place was there for several months, since this project was left unattended (before I went on board), because no one could find a fix for it, so they just stopped using it. Most likely, copy-paste error.

Thanks to all the guys for your ideas. Especially the first answer from Xearinox, which made me think about comparing all the modes. I will try to find the time to write a tool for parsing project / solution files into a four-column sheet listing all the properties for all configurations and platforms, so we can easily compare them. Thanks again.

Answer 2

Open the project settings page, go to Linker → System and study the SubSystem property. Make sure that it is set to the same value in all project configurations by switching the configuration from the configuration drop-down list.

Assuming that your intended entry point is main (or one of its variants, for example _tmain or wmain ), you must make sure that you use CONSOLE to use the SubSystem property.

Answer 3

WinMain as an entry point is missing.

Answer 4

In my case, the file I was trying to compile had the wrong properties.

I created a file with a changed symbol in the file extension, and so my project gave it the wrong element type: Does not participate in build .

After renaming, I turned on its properties and changed the element type to <reset to default> , which reset to C/C++ Compiler .