[Xapian-discuss] Compiling the PHP bindings with Cygwin ?

[Olly Betts]

On Tue, Feb 14, 2006 at 10:38:42AM +0100, Thomas Deniau wrote:
> Has anyone successfully compiled the PHP bindings with Cygwin (on W2K) ?

I know people have tried to build the Python bindings (and I've applied
a few patches to help that work).  I don't think I've heard from anyone
who's tried the PHP bindings.

> I usually use OS X and the PHP bindings work fine there (thanks for the
> astonishing work on Xapian !), but my web site is now production-ready and my
> web server runs Windows 2000.
> 
> I've successfully compiled xapian-core with cygwin (worked out of the box) and I
> almost got the PHP bindings to compile : I had to remove the '-g -O2' CXXFLAGS
> because when they are on, cc runs out of memory

I discovered that enormous compile-time memory requirements when
optimising are caused by the exception handling in each wrapped method.
In SVN HEAD I've factored out as much of the exception handling as I
could into a single function, which is then hooked by a minimal
exception handler from each wrapper.  I haven't measured the compiler
memory use, but for the Tcl bindings on x86_64 this change cut the
compile time by around a factor of 3 and halved the size of the stripped
library.

> now they are compiled, but the link fails : it says that all the PHP
> _zend symbols are undefined (and that's correct, we don't link with
> any PHP DLL).
> 
> I know the same error can be fixed on OS X with -undefined
> dynamic_lookup (since PHP will load our bindings...) but if I've
> googled correctly there is no such option on Windows, since the DLL
> system is different from the dynamic libraries system on Unix and the
> bundles system on Mac OS X.

Windows doesn't allow you to build a DLL with unresolved symbols.

And incidentally, OS X should work out of the box in the next release.

> So, has anyone managed to find the right commands to get these
> bindings compiled ? I thought of using pexport (from mingw) and
> dlltool to build a .a version of the PHP DLL that Apache loads, but
> statically linking with it does not seem to be the proper way....

I think this is the correct way.  The .a that you generate like this
isn't actually a static version of the DLL - it's what they call an
"import library", and effectively contains stub definitions which
you link against.  But at run time the DLL is loaded and used.

If you've a fairly recent Cygwin (binutils 2.13.90-20030111-1 or later),
you should be able to just link against the PHP DLL (ld can sort out the
imports on the fly).  You can check the binutils version with:

ld --version

You may need to pass this flag when linking to get that to work:

-Wl,--enable-runtime-pseudo-reloc

You can easily try this by building PHP's xapian-bindings with:

make xapian_la_LDFLAGS='-avoid-version -module -no-undefined -Wl,--enable-runtime-pseudo-reloc'

If that works, I can change configure to always pass this where
appropriate (xapian-core already does this).

Cheers,
    Olly