Re: [xml] win32 getaddrinfo

[Michael Stahl <Michael Stahl Sun com>]

Roumen Petrov wrote:
> Michael Stahl wrote:
> > Rob Richards wrote:
> > > Michael Stahl wrote:
> > > > Rob Richards wrote:
> > > >   
> > > > > >       
> > > </snip>
> > > > > >   
> > > > > >       
> > > > > I think I finally understand what you are trying to do. You are building 
> > > > > on Win 2003 with VS 2005 and then trying to use the lib on on Win2K or 
> > > > > lower and it is there that it is failing to link?
> > > > >     
> > > > well, it fails to link with vs 2005 already because libxml (using 2.6.31 
> > > > here) is not linked against ws2_32.dll, so ld (or whatever msft calls its 
> > > > equivalent) complained that getaddrinfo and freeaddrinfo are undefined 
> > > > symbols.
> > > >   
> > > I get it now and thought that was only an issue with VS 2008. Can you 
> > > try building from SVN or even a snapshot. The lib was added just after 
> > > the .31 release.
> > ok, i have built a snapshot (downloaded friday iirc). building works, and 
> > the dll is linked against ws2_32.dll.
> >
> > > > > Can you try the following patch?
> > > > > Index: wsockcompat.h
> > > > > ===================================================================
> > > > > --- wsockcompat.h    (revision 3721)
> > > > > +++ wsockcompat.h    (working copy)
> > > > > @@ -21,6 +21,7 @@
> > > > >  
> > > > >  /* Check if ws2tcpip.h is a recent version which provides getaddrinfo() */
> > > > >  #if defined(GetAddrInfo)
> > > > > +#include <wspiapi.h>
> > > > >  #define HAVE_GETADDRINFO
> > > > >  #endif
> > > > >  #endif
> > > > >     
> > > > ah yes, that seems to work fine here, and is obviously the cleaner way to 
> > > > do it.
> > > >   
> > > If the build from SVN fixes the initial problem, can you try using it on 
> > > w Win2K machine? It's possible that the patch might not be needed though 
> > > after more research I have doubts. I'm looking around here for an old OS 
> > > to test on as well. I'm pretty sure I have an old VM image lying around 
> > > here somewhere.
> > so today i finally got access to a win2k machine. the result:
> > with 2.6.31+my patch, the application runs.
> > with the snapshot, the application fails to run, and displays a message 
> > box complaining that ws2_32.dll could not be found.
> >
> > so, i would suggest you revert the patch that introduced linking to 
> > ws2_32.dll, and use wspapi.h instead.
> >
> > regards
> > michael
>
> Michael,
> If "my patch" is you patch first posted to the list I think that you 
> understand that patch break libxml2 build on other platforms. Is you 
> "suggestion" to broke libxml2 intentional ?

errm, no, by "my patch" i meant the general approach of including the 
header wspiapi.h _instead_of_ linking against ws2_32.dll, however that may 
be implemented so that it works on all supported platforms. i have merely 
told how i could get it to work on my setup (building on win2k3 and 
deploying on win2k), and that the status quo does _not_ work in this 
setup. i will leave the details to those who actually know something about 
win32.

> Rob,
> may be the problem can be resolved with this proof of concept code:
> do {
>    /* resolve getaddrinfo at run time instead at compile time */
>    h  = LoadLibraryA("ws2_32");
>    if (h != NULL) {
>      f = GetProcAddress(h, "getaddrinfo");
>      if (f == NULL) {
>        FreeLibrary(h);
>        h = NULL;
>      } else {
>        /* */
>      }
>    }
>    h  = LoadLibraryA("wship6");
>    if (h != NULL) {
>      f = GetProcAddress(h, "getaddrinfo");
>      if (f == NULL) {
>        FreeLibrary(h);
>        h = NULL;
>      } else {
>        call f ....
>      }
>    }
>    /* fail-back to gethostbyname */
>    ....
> } while (0);
>
>
> As I understand wship6 is not default on platforms before nt 5.1.
>
> Roumen

well, the msdn page for getaddrinfo claims that this is basically what the 
macro in wspiapi.h does.

michael

--
"Experience is that marvelous thing that enables you recognize a
 mistake when you make it again." -- F. P. Jones