FIX: /YX and /Yc Incorrectly Allowed in Project Settings

ID: Q122304

The information in this article applies to:

Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 4.0, 4.1, 4.2, 5.0

SYMPTOMS

Combining compiler switches /Yc and /Yu with the /YX option causes the following error:


   fatal error C1852: <PCH_file_name> is not a valid precompiled
      header file
   Error executing cl.exe.

CAUSE

In the example given in the More Information section, the /YX switch forces a new PCH file to be generated for the newly added source file. The project files that use the /Yu switch are dependent on the file built using the /Yc compiler switch. They will be recompiled because the precompiled header is newer than their OBJ files. The error is generated because the requirements for the PCH files are not met.

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article. This problem was corrected in Microsoft Visual C++, version 6.0.

MORE INFORMATION

Steps to Reproduce Problem

This problem can be demonstrated using the SCRIBBLE, step 7, project; it uses the /Yc and /Yu switches.

Add a new C++ (.cpp) souce file to the project.

In the Project Settings dialog box for the new file, select the C/C++ tab and the Precompiled Headers category.

Click the Automatic Use of Precompiled Headers box.

Choose the OK button at the bottom of the Project Settings dialog box.

When the build engine processes the newly added source file, it will rebuild the default PCH file. Compilation of the next source file that depends on the default PCH file will fail because the default PCH file no longer matches up to the original sources. The C1852 error listed in the SYMPTOMS section above will be generated.

NOTE: If the source file added to the SCRIBBLE project is a C source file, not a C++ source, the error build error generated will be as follows:


   fatal error C1853: <PCH_file_name> is not a precompiled header file
      created with this compiler
   Error executing cl.exe.

Additional query words: kbVC400bug

Keywords : kbide kbVC kbVC500bug kbVC600fix kbGrpDSTools
Version : 2.0 2.1 4.0 4.1 4.2 5.0
Platform : NT WINDOWS
Issue type : kbbug