How to make NSIS RMDir operate on subdirectories?

Question

In an NSIS installer script I have:

RMDir "$INSTDIR"

Now, if the user sets the installation directory to C:\Program Files\Product, it works fine, however if they install to something deeper, such as C:\Program Files\Company\Product for example, RMDir gets rid of "Product" but not "Company". How can I make it delete each empty directory down to the root (WITHOUT using /r)... e.g. delete Product if empty, delete Company if empty, delete Program Files if empty, and so on?

---

EDIT: The function I ended up using:

# Delete empty directories recursively
var deleteDir
var dirLength
Function un.PathDeleteEmptyDirRecurse
ClearErrors
loop:
    Sleep 50 ; Without a small delay here, the directory sometimes won't get removed
    RMDir "$deleteDir" ; Remove the directory
    IfErrors end
    strlen $dirLength $deleteDir ; Store the length of the path
    intcmp $dirLength 3 end end ; If the length of the path is <= 3 (e.g. C:\), we're at the root drive
    GetFullPathName $deleteDir "$deleteDir\.." ; <path>\.. results in the parent directory of <path>
    IfErrors end loop
end:
FunctionEnd

Answer 1

I assume you want this in the uninstaller and not the installer:

Function un.PathDeleteEmptyDirRecurse 
exch $0
push $1
ClearErrors
loop:
RMDir $0
IfErrors end
strlen $1 $0
intcmp $1 3 end end ;root of drive?
GetFullPathName $0 "$0\.."
IfErrors end loop
end:
pop $1
pop $0
FunctionEnd

...

push $instdir
call un.PathDeleteEmptyDirRecurse