Compiler Warning (level 1) C4727

 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at Compiler Warning (level 1) C4727.

PCH named pch_file with same timestamp found in obj_file_1 and obj_file_2. Using first PCH.

C4727 occurs when compiling multiple compilands with /Yc, and where the compiler was able to mark all .obj files with the same .pch timestamp.

To resolve, compile one source file with /Yc /c (creates pch), and the others compile separately with /Yu /c (uses pch), then link them together.

So, if you did the following and generates C4727:

cl /clr /GL a.cpp b.cpp c.cpp /Ycstdafx.h

You would do the following instead:

cl /clr /GL a.cpp /Ycstdafx.h /c

cl /clr /GL b.cpp c.cpp /Yustdafx.h /link a.obj

For more information, see

Show: