Re: Strange linker errors (LNK2005) in Release build only .... why ??

So is there no way to override/replace malloc/free with my implementation in
a dll ??

Thanks,
Krishnan

"Nanda" <nandagopal.seshagiri@xxxxxxxxx> wrote in message
news:eTkBJbe5FHA.884@xxxxxxxxxxxxxxxxxxxxxxx
> Hi,
>
> U are seeing this problem only in release build because, in debug, the
free
> and malloc are exported or used as _free_dbg and _malloc_dbg from
> msvcrt70d.dll, where as in release they are exported as free and malloc.
>
> nanda
>
> "Krishnan R.S." <rskrishnan@xxxxxxxxxxx> wrote in message
> news:%23$H7jjV5FHA.3636@xxxxxxxxxxxxxxxxxxxxxxx
> > Hello All,
> >
> > First off I'd like to say I am not mixing the static and dll
versions
> of
> > the runtime in my dll - I use /MDd for the debug and /MD for the release
> > versions of DLMAlloc.dll. I tried all sorts of options for the linker
but
> it
> > seems adamantly stuck on not building the release version alone!
> >
> > I've got a project where I'm trying to use dlmalloc.c instead of the
> > usual vc7 malloc() - i.e. I want to build a drop in replacement for the
> > default vc7 malloc() allocator. To use this allocator in all my dlls I
> need
> > to build this as a separate dll - called say DLMalloc.dll.
> >
> > I've attached a zip file containing the source + the vcproj files if
> you
> > are interested ...
> >
> > I have a project in MSVC 7.1 setup to build a dll (not a static
lib) -
> > all seems fine in the debug build. I am able to build my DLMalloc.dll,
and
> > DLMalloc.lib - and use it to build my app, successfuly links and works
> too!
> >
> > The problem comes when I try to build a release build of
> > DLMalloc.dll/DLMalloc.lib. The compile goes fine - but I get a linker
> error.
> > The linker thinks that _free and _malloc are defined multiple times -
why
> ??
> >
> > Why do I get this symbol conflict only on release builds ? I suspect
> that
> > the MSVCR71.dll has internally linked to the malloc/free implementations
> > available in the runtime - is that possible ?? If so why does it work
on
> > the debug build ??
> >
> > I tried switching to incremental linking on the release build (using
> > /OPT:NOREF /OPT:NOICF with /INCREMENTAL) but no luck whatsoever.
> > I tried looking at the verbose output of the linker - and it seems
> like
> > the reference to free is from crtdll.obj - see snippet below.
> >
> > ---snippet from the verbose linker output ---
> > Found __imp__free
> > Referenced in MSVCRT.lib(crtdll.obj)
> > Loaded MSVCRT.lib(MSVCR71.dll)
> > MSVCRT.lib(MSVCR71.dll) : error LNK2005: _free already defined in
> malloc.obj
> > --- end snippet ----
> >
> > I may very well be on the wrong track with my diagnosis ....
> > I'd appreciate any help you can give me on this issue.
> >
> > Thanks,
> > Krishnan
> >
> >
> >
> >
> >
>
>


.

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