After making the following change in port.h:
/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
/* open() replacement to allow delete of held files */
extern int	win32_open(const char*,int,...);
#ifdef _MSC_VER
#define 	open	win32_open
#else
#define 	open(a,b,...)	win32_open(a,b,##__VA_ARGS__)
#endif
/* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */

I can get a little further towards a build of libpq...

U:\postgresql-snapshot\src>nmake /f win32.mak

Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
Copyright (C) Microsoft Corp 1988-1998. All rights reserved.

        cd include
        if not exist pg_config.h copy pg_config.h.win32 pg_config.h
        cd ..
        cd interfaces\libpq
        nmake /f win32.mak

Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
Copyright (C) Microsoft Corp 1988-1998. All rights reserved.

Building the Win32 static library...

        cl.exe @u:\tmp\nma01920.
getaddrinfo.c
        cl.exe @u:\tmp\nmb01920.
thread.c
..\..\include\utils/elog.h(37) : warning C4005: 'ERROR' : macro
redefinition
        C:\Program Files\Microsoft SDK\Include\.\wingdi.h(98) : see
previous definition of 'ERROR'
        cl.exe @u:\tmp\nmc01920.
inet_aton.c
        cl.exe @u:\tmp\nmd01920.
crypt.c
        cl.exe @u:\tmp\nme01920.
path.c
        cl.exe @u:\tmp\nmf01920.
dllist.c
        cl.exe @u:\tmp\nmg01920.
md5.c
        cl.exe @u:\tmp\nmh01920.
ip.c
        cl.exe @u:\tmp\nmi01920.
wchar.c
        cl.exe @u:\tmp\nmj01920.
encnames.c
        cl.exe @u:\tmp\nmk01920.
win32.c
fe-auth.c
..\..\include\libpq/libpq-be.h(21) : fatal error C1083: Cannot open
include file: 'sys/time.h': No such file or directory
fe-protocol2.c
fe-protocol3.c
fe-connect.c
fe-exec.c
fe-lobj.c
C:\lang\VC98\include\io.h(176) : error C2375: 'pgrename' : redefinition;
different linkage
        ..\..\include\port.h(45) : see declaration of 'pgrename'
C:\lang\VC98\include\io.h(238) : error C2375: 'win32_open' :
redefinition; different linkage
        ..\..\include\port.h(55) : see declaration of 'win32_open'
C:\lang\VC98\include\io.h(244) : error C2375: 'pgunlink' : redefinition;
different linkage
        ..\..\include\port.h(46) : see declaration of 'pgunlink'
fe-misc.c
fe-print.c
fe-secure.c
pqexpbuffer.c
NMAKE : fatal error U1077: 'cl.exe' : return code '0x2'
Stop.
NMAKE : fatal error U1077: 'C:\lang\VC98\bin\NMAKE.EXE' : return code
'0x2'
Stop.

Some notions:
1.  For the macro ERROR above, we should #undef ERROR

2.  #include <sys/time.h> should have #ifndef _MSC_VER around it.  I did
this:
#ifndef _MSC_VER
#include <sys/time.h>
#endif

3.  For the errors in io.h, it appears that there are some macros that
redefine rename and unlink
I did this:
/*----------------------------------------------------------------------
---
 *
 * fe-lobj.c
 *	  Front-end large object interface
 *
 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql-server/src/interfaces/libpq/fe-lobj.c,v
1.48 2004/03/05 01:53:59 tgl Exp $
 *
 
*-----------------------------------------------------------------------
--
 */
#include "postgres_fe.h"

#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>

#ifdef WIN32
#include "win32.h"
#undef rename
#undef open
#undef unlink
#include "io.h"
#else
#include <unistd.h>
#endif

There remains one problem on the build -- an unresolved symbol:
U:\postgresql-snapshot\src>nmake /f win32.mak

Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
Copyright (C) Microsoft Corp 1988-1998. All rights reserved.

        cd include
        if not exist pg_config.h copy pg_config.h.win32 pg_config.h
        cd ..
        cd interfaces\libpq
        nmake /f win32.mak

Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
Copyright (C) Microsoft Corp 1988-1998. All rights reserved.

Building the Win32 static library...

        cl.exe @u:\tmp\nma02216.
fe-auth.c
        link.exe -lib @u:\tmp\nmb02216.
        cl.exe @u:\tmp\nmc02216.
libpqdll.c
        rc.exe /l 0x409 /fo".\Release\libpq.res" libpq.rc
        link.exe @u:\tmp\nmd02216.
   Creating library .\Release\libpqdll.lib and object
.\Release\libpqdll.exp
libpq.lib(fe-connect.obj) : error LNK2001: unresolved external symbol
_set_noblock
.\Release\libpq.dll : fatal error LNK1120: 1 unresolved externals
NMAKE : fatal error U1077: 'link.exe' : return code '0x460'
Stop.
NMAKE : fatal error U1077: 'C:\lang\VC98\bin\NMAKE.EXE' : return code
'0x2'
Stop.

This stuff really needs to be functional with compilers besides GCC
derivatives.

Wed, 31 Mar 2004 13:22:06 -0800
"Dann Corbit" <DCorbit@connx.com>
The incompaitiblity of libpq and non-GCC compilers

Some of this looks at first glance like it doesn't belong in an 
interface library - maybe we should be wrapping more in #ifdef FRONTEND ?

cheers

andrew

Dann Corbit wrote:

>After making the following change in port.h:
>/* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
>/* open() replacement to allow delete of held files */
>extern int	win32_open(const char*,int,...);
>#ifdef _MSC_VER
>#define 	open	win32_open
>#else
>#define 	open(a,b,...)	win32_open(a,b,##__VA_ARGS__)
>#endif
>/* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
>
>I can get a little further towards a build of libpq...
>
>U:\postgresql-snapshot\src>nmake /f win32.mak
>
>Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
>Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
>
>        cd include
>        if not exist pg_config.h copy pg_config.h.win32 pg_config.h
>        cd ..
>        cd interfaces\libpq
>        nmake /f win32.mak
>
>Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
>Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
>
>Building the Win32 static library...
>
>        cl.exe @u:\tmp\nma01920.
>getaddrinfo.c
>        cl.exe @u:\tmp\nmb01920.
>thread.c
>..\..\include\utils/elog.h(37) : warning C4005: 'ERROR' : macro
>redefinition
>        C:\Program Files\Microsoft SDK\Include\.\wingdi.h(98) : see
>previous definition of 'ERROR'
>        cl.exe @u:\tmp\nmc01920.
>inet_aton.c
>        cl.exe @u:\tmp\nmd01920.
>crypt.c
>        cl.exe @u:\tmp\nme01920.
>path.c
>        cl.exe @u:\tmp\nmf01920.
>dllist.c
>        cl.exe @u:\tmp\nmg01920.
>md5.c
>        cl.exe @u:\tmp\nmh01920.
>ip.c
>        cl.exe @u:\tmp\nmi01920.
>wchar.c
>        cl.exe @u:\tmp\nmj01920.
>encnames.c
>        cl.exe @u:\tmp\nmk01920.
>win32.c
>fe-auth.c
>..\..\include\libpq/libpq-be.h(21) : fatal error C1083: Cannot open
>include file: 'sys/time.h': No such file or directory
>fe-protocol2.c
>fe-protocol3.c
>fe-connect.c
>fe-exec.c
>fe-lobj.c
>C:\lang\VC98\include\io.h(176) : error C2375: 'pgrename' : redefinition;
>different linkage
>        ..\..\include\port.h(45) : see declaration of 'pgrename'
>C:\lang\VC98\include\io.h(238) : error C2375: 'win32_open' :
>redefinition; different linkage
>        ..\..\include\port.h(55) : see declaration of 'win32_open'
>C:\lang\VC98\include\io.h(244) : error C2375: 'pgunlink' : redefinition;
>different linkage
>        ..\..\include\port.h(46) : see declaration of 'pgunlink'
>fe-misc.c
>fe-print.c
>fe-secure.c
>pqexpbuffer.c
>NMAKE : fatal error U1077: 'cl.exe' : return code '0x2'
>Stop.
>NMAKE : fatal error U1077: 'C:\lang\VC98\bin\NMAKE.EXE' : return code
>'0x2'
>Stop.
>
>Some notions:
>1.  For the macro ERROR above, we should #undef ERROR
>
>2.  #include <sys/time.h> should have #ifndef _MSC_VER around it.  I did
>this:
>#ifndef _MSC_VER
>#include <sys/time.h>
>#endif
>
>3.  For the errors in io.h, it appears that there are some macros that
>redefine rename and unlink
>I did this:
>/*----------------------------------------------------------------------
>---
> *
> * fe-lobj.c
> *	  Front-end large object interface
> *
> * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
> * Portions Copyright (c) 1994, Regents of the University of California
> *
> *
> * IDENTIFICATION
> *	  $PostgreSQL: pgsql-server/src/interfaces/libpq/fe-lobj.c,v
>1.48 2004/03/05 01:53:59 tgl Exp $
> *
> 
>*-----------------------------------------------------------------------
>--
> */
>#include "postgres_fe.h"
>
>#include <fcntl.h>
>#include <sys/stat.h>
>#include <errno.h>
>
>#ifdef WIN32
>#include "win32.h"
>#undef rename
>#undef open
>#undef unlink
>#include "io.h"
>#else
>#include <unistd.h>
>#endif
>
>There remains one problem on the build -- an unresolved symbol:
>U:\postgresql-snapshot\src>nmake /f win32.mak
>
>Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
>Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
>
>        cd include
>        if not exist pg_config.h copy pg_config.h.win32 pg_config.h
>        cd ..
>        cd interfaces\libpq
>        nmake /f win32.mak
>
>Microsoft (R) Program Maintenance Utility   Version 6.00.8168.0
>Copyright (C) Microsoft Corp 1988-1998. All rights reserved.
>
>Building the Win32 static library...
>
>        cl.exe @u:\tmp\nma02216.
>fe-auth.c
>        link.exe -lib @u:\tmp\nmb02216.
>        cl.exe @u:\tmp\nmc02216.
>libpqdll.c
>        rc.exe /l 0x409 /fo".\Release\libpq.res" libpq.rc
>        link.exe @u:\tmp\nmd02216.
>   Creating library .\Release\libpqdll.lib and object
>.\Release\libpqdll.exp
>libpq.lib(fe-connect.obj) : error LNK2001: unresolved external symbol
>_set_noblock
>.\Release\libpq.dll : fatal error LNK1120: 1 unresolved externals
>NMAKE : fatal error U1077: 'link.exe' : return code '0x460'
>Stop.
>NMAKE : fatal error U1077: 'C:\lang\VC98\bin\NMAKE.EXE' : return code
>'0x2'
>Stop.
>
>This stuff really needs to be functional with compilers besides GCC
>derivatives.
>
>---------------------------(end of broadcast)---------------------------
>TIP 3: if posting/reading through Usenet, please send an appropriate
>      subscribe-nomail command to majordomo@postgresql.org so that your
>      message can get through to the mailing list cleanly
>
>  
>


Wed, 31 Mar 2004 19:07:48 -0500
Andrew Dunstan <andrew@dunslane.net>
Re: The incompaitiblity of libpq and non-GCC compilers