Mail Archives: cygwin/2003/02/10/14:15:13
Ralf Habacker wrote:
>>1) x86 DLL (and EXE)
>>2) x86 archive static
>>3) x86 archive import
>>4) other
>>
>>Do NOT try to combine 2) and 3) -- which is what all of your suggestions
>>in this email would do.
>>
>
> [1]
> What about extending the 'file' tool, which supports already 1, (2 combined with
> 3) and 4 ?
> You have written (and I have checked this too) that 'file's execution time is
> independend from the object file size, so this would speedup this detecion.
Now that's an idea, but we'd need to get it into the "real" file
distribution -- otherwise, cross-compile builds won't work.
> I've taken a look into the file source and have seen the only thing I don't know
> is how to define a rule for a string with a variable fileoffset, because
> '_dll_iname' is, as far as i can see, one of major identifier of import
> libraries.
Yep. Believe it or not, I *did* look at this idea early on -- and you've
hit on the reason I didn't pursue it.
> For an example how to add support with fixed file offset
> /usr/lib/libintl.dll.a):
>
> $ diff -ubB archive.orig archive
> --- MagDir/archive.orig 2003-02-10 09:01:41.000000000 +0100
> +++ MagDir/archive 2003-02-10 09:00:36.000000000 +0100
> @@ -79,6 +79,8 @@
> >0 beshort 3 - shared library module
> >0 beshort 4 - debug break-pointed module
> >0 beshort 5 - absolute code program module
> +>866 string _dll_iname import library
> +
> 0 string \<ar> System V Release 1 ar archive
> 0 string =<ar> archive
> #
Sure -- but as you say, that only works for fixed offsets. Now,
**most** import libs will need only the fixed offset, especially if you
hunt for _dll_iname instead of " I " in $NM's output as I was doing.
This is a very good idea.
But, you'd still need to check all "static libs" to see if they are
really import libs after all. The good news it that we expect this to
happen only rarely: when an import lib is a "hybrid" lib with static
objs "in front" --> the modified 'file' test incorrectly identifies it
as a static archive.
Question: for "normal" import libs (that is, excluding the hybrids like
libcygwin.a), does your version work always? Or does _dll_iname 'float
around' even within otherwise normal import libs?
Downside: we can't use this idea in libtool-1.5. We have to wait until
after your change (after suitable debugging, of course) makes it into
not just OUR file distribution, but the "real" file distribution.
Summary: sounds good. Please pursue, and once your modification has
been accepted into 'file' and the upgrade has reasonable penetration on
non-cygwin platforms, then we can *really* speed up win32_libid() --
maybe by libtool-1.5.1 or .2. But for now, I think we'll have to stick
with the moderate speedup that my proposal allows.
--Chuck
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