Libpq.dll: File not recognized

On 06/30/10 3:23 PM, Bidski wrote:

Hi all,
I downloaded the "one-click" installer for PostgreSQL 9.0 beta2 for
Windows x64 (postgresql-9.0.0-beta2-windows-x64.exe) and installed it
on my Windows 7 64 bit system. Installation seemed to go off without a
hitch, but when I tried to link to libpq in my project I received the
following error.

C:\Program Files\PostgreSQL\lib/libpq.dll: file not recognized:
File format not recognized

collect2: ld returned 1 exit status

I originally thought that this might have something to do with the use
of different compilers/linkers (compiler/linker that I am using
compared to the one used with to build libpq), but now Im not so sure.

Some system info.....

OS: Windows 7 64-bit

MSYS ver: 1.0.14

MinGW ver: 4.5.0

Make ver: GNU make 3.81

If it matters ..... My IDE is Eclipse Galileo and I am compiling my
project using the MinGW toolchain.

wild guess says your project is 64 bit, but libpq.dll is 32 bit.

John R Pierce <pierce@hogranch.com> writes:

wild guess says your project is 64 bit, but libpq.dll is 32 bit.

Why would there be a 32bit dll in the 64bit pre-built package?

Regards
Bidski

--------------------------------------------------
From: "John R Pierce" <pierce@hogranch.com>
Sent: Thursday, July 01, 2010 8:34 AM
To: <pgsql-bugs@postgresql.org>
Subject: Re: [BUGS] Libpq.dll: File not recognized

On 06/30/10 3:40 PM, Bidski wrote:

John R Pierce <pierce@hogranch.com> writes:

wild guess says your project is 64 bit, but libpq.dll is 32 bit.

Why would there be a 32bit dll in the 64bit pre-built package?

look and see if there's another /lib64/ or similar directory ?

I didn't notice earlier that you are running the postgres 9 beta.

John R Pierce <pierce@hogranch.com> writes:

look and see if there's another /lib64/ or similar directory ?

Nope, no lib64 directory or anything like that, just lib directory.

I didn't notice earlier that you are running the postgres 9 beta.

Yep, Im running PostgreSQL 9.0 beta2

Regards
Bidski

On Wed, Jun 30, 2010 at 11:23 PM, Bidski <bidski@bigpond.net.au> wrote:

Hi all,

I downloaded the "one-click" installer for PostgreSQL 9.0 beta2 for Windows
x64 (postgresql-9.0.0-beta2-windows-x64.exe) and installed it on my Windows
7 64 bit system. Installation seemed to go off without a hitch, but when I
tried to link to libpq in my project I received the following error.

    C:\Program Files\PostgreSQL\lib/libpq.dll: file not recognized: File
format not recognized

Don't link against the DLL, link against the .lib.

Some system info.....

OS: Windows 7 64-bit

MSYS ver: 1.0.14

MinGW ver: 4.5.0

Make ver: GNU make 3.81

If it matters ..... My IDE is Eclipse Galileo and I am compiling my project
using the MinGW toolchain.

The server is built with VC++ 2008 - I have no idea if Mingw can use
64bit VC++ libraries.

--
Dave Page
EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise Postgres Company

"Dave Page" <dpage@pgadmin.org> writes:

Don't link against the DLL, link against the .lib.

Isnt the .lib the static library and the dll the shared library? And Im not
linking against the dll specifically, that is the library that g++ is
wanting to link to. My link command is

g++ -Wl,--enable-auto-import -o"MRP.exe" ./src/DB.o ./src/catlist.o
./src/inventory.o ./src/mrp_app.o ./src/mrp_frame.o
./res/resources.rc.o -lpq -L"C:\MinGW\lib" -L"C:\Program
Files\PostgreSQL\lib" -mwindows `wx-config --libs base,core,adv,xrc`

The server is built with VC++ 2008 - I have no idea if Mingw can use
64bit VC++ libraries.

I also have no idea for certain, but I should think so. My understanding of
the whole thing is that a DLL made for windows should be linkable to any
windows application regardless of compiler/linker, if its not then what is
the point?

Regards
Bidski

On Thu, Jul 1, 2010 at 9:00 AM, Bidski <bidski@bigpond.net.au> wrote:

"Dave Page" <dpage@pgadmin.org> writes:

Don't link against the DLL, link against the .lib.

Isnt the .lib the static library and the dll the shared library?

No, it should be the import library for the DLL.

And Im not
linking against the dll specifically, that is the library that g++ is
wanting to link to. My link command is

  g++ -Wl,--enable-auto-import -o"MRP.exe"  ./src/DB.o ./src/catlist.o
./src/inventory.o ./src/mrp_app.o ./src/mrp_frame.o ./res/resources.rc.o
-lpq -L"C:\MinGW\lib" -L"C:\Program Files\PostgreSQL\lib" -mwindows
`wx-config --libs base,core,adv,xrc`

That looks right - and should be looking for the .lib (or a .a) as you
just have -lpq. Should there be a -m64 in there though? Try compiling
a test program and verify that you actually are getting 64 bit output.

The server is built with VC++ 2008 - I have no idea if Mingw can use
64bit VC++ libraries.

I also have no idea for certain, but I should think so. My understanding of
the whole thing is that a DLL made for windows should be linkable to any
windows application regardless of compiler/linker, if its not then what is
the point?

The DLLs should be portable, but the import library might not be. I
vaguely recall that VC++ cannot use a Mingw import library - though
you can fairly easily create a compatible library from the
incompatible one. I don't recall the details though - Google is your
friend.

--
Dave Page
EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise Postgres Company