Article ID: 139476 - Last Review: December 2, 2003 - Revision: 2.0

FIX: File Time Incorrect After Saving During Build

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This article was previously published under Q139476

SYMPTOMS

If a source file is saved while the project is being built, the relationships between the source file and the .obj file may be incorrect. The saved source file may have an earlier date than the .obj file that was created from the previous version of the source file.

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CAUSE

The problem of file modify or save time being incorrect is caused by the Developer's Studio doing front-end processing on all the files before it creates the .obj files. This makes it possible to save a changed file after the earlier version was processed but before the .obj file is created.

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STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

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MORE INFORMATION

Steps to Reproduce Problem

Open one of the files in a project, but don't open the file that will be used to create a .pch file (Stdafx.cpp in an MFC application).
Start a Rebuild All.
Introduce a syntax error in the open file, but do not save it.
While the Rebuild All progresses, look in the output window, and wait for it to compile the open file.
As soon as it finishes compiling the file, and before it says "Generating Code," save the changed file that has a syntax error. Because the changes occurred after the front end of the compiler has processed the file, there will be no errors in the build. The .obj file will however have a later date because it was created in the "Generating Code" phase.
Do a Build (not a Rebuild All). Nothing will happen, and the changed file will not be compiled.
Look at the dates of the files, and confirm that the .obj file is newer than the file that was changed.

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