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visual-c++dumpbin

The dumpbin utility gives a different result if I include a path

Investigating the bit width of DLLs on my Windows 10/64 bit box with Visual Studiop 2013 installed.

dumpbin /headers C:\windows\system32\msvcp120.dll | findstr machine

reports: 8664 machine (x64)

but 

cd C:\windows\system32\
dumpbin /headers .\msvcp120.dll | findstr machine

reports: 14C machine (x86) 32 bit word machine

I've tried it on several machines with the same result. What's going on ?

Solution

  • This is the file system redirector at work, always active on a 64-bit OS when you look at the c:\windows\system32 directory. You are actually looking at c:\windows\syswow64\msvcp120.dll, thus the machine type is x86. Caused primarily by running the 32-bit version of dumpbin.exe, like most users would. Only the 64-bit version (vc/bin/amd64 directory) does not get redirected.

    I was puzzled a bit and discovered one aspect of the redirector I did not know before. It redirects only relative paths. So .\msvcp120.dll or ..\system32\msvcp120.dll. But not a full path, like c:\windows\system32\msvcp120.dll. Drive letter is not actually important.