Gist does not build with VC++ anymore

I've updated my VC++ build env with latest CVS, and it no
longer builds because of changes to GIST:

src\backend\access\gist\gistutil.c(237) : error C2057:
expected constant expression
src\backend\access\gist\gistutil.c(237) : error C2466: cannot
allocate an array of constant size 0
src\backend\access\gist\gistutil.c(237) : error C2133: 'storage' :
unknown size

The problem appears to come from:
#define GEVHDRSZ (offsetof(GistEntryVector, vector[0]))

Which can't be used in this context.

What would be the proper fix for that?

Hmm. Now that I look at it more clearly, it seems Hiroshi has a fix for
this in his submitted patch (that still had a lot of other problems in
the rest of it). I'm not sure if it's the proper fix, but it's there.
Comments on it?

--- src/backend/access/gist/gistutil.c.orig	Thu Jun 22 20:46:55 2006
+++ src/backend/access/gist/gistutil.c	Thu Jun 22 20:47:22 2006
@@ -228,6 +228,12 @@
 /* 
  * makes union of two key
  */
+
+#ifdef _MSC_VER
+#undef GEVHDRSZ
+#define GEVHDRSZ        (offsetof(GistEntryVector, vector))
+#endif
+
 static void
 gistMakeUnionKey( GISTSTATE *giststate, int attno,
 					GISTENTRY	*entry1, bool
isnull1, 	

//Magnus

I've updated my VC++ build env with latest CVS, and it no longer
builds because of changes to GIST:

src\backend\access\gist\gistutil.c(237) : error C2057:
expected constant expression
src\backend\access\gist\gistutil.c(237) : error C2466:

cannot allocate

an array of constant size 0
src\backend\access\gist\gistutil.c(237) : error C2133: 'storage' :
unknown size

The problem appears to come from:
#define GEVHDRSZ (offsetof(GistEntryVector, vector[0]))

Which can't be used in this context.

What would be the proper fix for that?

Hmm. Now that I look at it more clearly, it seems Hiroshi has
a fix for this in his submitted patch (that still had a lot
of other problems in the rest of it). I'm not sure if it's
the proper fix, but it's there.

While I'm spamming everybody anyway, here's another thing that might fix
it? This one compiles and tests, and I *think* it does the right
thing... If it's correct, I think it looks like a cleaner solution.

//Magnus

RCS file: /projects/cvsroot/pgsql/src/include/access/gist.h,v
retrieving revision 1.52
diff -c -r1.52 gist.h
*** src/include/access/gist.h   5 Mar 2006 15:58:53 -0000       1.52
--- src/include/access/gist.h   24 Jun 2006 17:20:28 -0000
***************
*** 142,148 ****
        GISTENTRY       vector[1];
  } GistEntryVector;

! #define GEVHDRSZ (offsetof(GistEntryVector, vector[0]))

  /*
   * macro to initialize a GISTENTRY
--- 142,148 ----
        GISTENTRY       vector[1];
  } GistEntryVector;

! #define GEVHDRSZ (offsetof(GistEntryVector, vector))

/*
* macro to initialize a GISTENTRY

Patch applied. It seems offsetof() can only find structure members in
MSVC, not the offset of array elements in structures. Anyway,
offsetof() was finding the first element, so the "[0]" is not needed.

---------------------------------------------------------------------------

Magnus Hagander wrote:

I've updated my VC++ build env with latest CVS, and it no longer
builds because of changes to GIST:

src\backend\access\gist\gistutil.c(237) : error C2057:
expected constant expression
src\backend\access\gist\gistutil.c(237) : error C2466:

cannot allocate

an array of constant size 0
src\backend\access\gist\gistutil.c(237) : error C2133: 'storage' :
unknown size

The problem appears to come from:
#define GEVHDRSZ (offsetof(GistEntryVector, vector[0]))

Which can't be used in this context.

What would be the proper fix for that?

Hmm. Now that I look at it more clearly, it seems Hiroshi has
a fix for this in his submitted patch (that still had a lot
of other problems in the rest of it). I'm not sure if it's
the proper fix, but it's there.

While I'm spamming everybody anyway, here's another thing that might fix
it? This one compiles and tests, and I *think* it does the right
thing... If it's correct, I think it looks like a cleaner solution.

//Magnus

RCS file: /projects/cvsroot/pgsql/src/include/access/gist.h,v
retrieving revision 1.52
diff -c -r1.52 gist.h
*** src/include/access/gist.h   5 Mar 2006 15:58:53 -0000       1.52
--- src/include/access/gist.h   24 Jun 2006 17:20:28 -0000
***************
*** 142,148 ****
GISTENTRY       vector[1];
} GistEntryVector;

! #define GEVHDRSZ (offsetof(GistEntryVector, vector[0]))

/*
* macro to initialize a GISTENTRY
--- 142,148 ----
GISTENTRY       vector[1];
} GistEntryVector;

! #define GEVHDRSZ (offsetof(GistEntryVector, vector))

/*
* macro to initialize a GISTENTRY

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