Thread: Getting iPhone Simulator App to compile with libpq on Snow Leopard

In my quest to create a simple PostgreSQL program that runs on the
iPhone I have ran into some problems.

The first issue I had with my build was libpq being compiled for
architecture of type x86_64 by default on Snow Leopard and the
Simulator being i386 so my build would fail telling me libpq was the
wrong architecture type. I was able to get around this issue as found
here -> http://stackoverflow.com/questions/1678381/connect-iphone-app-to-postgresql-using-libpq.

Now I'm getting a new "Undefined symbols" issue.
Here is the code that is attempting to connect to PostgreSQL

//
//  iPhonePgAppDelegate.m
//  iPhonePg
//
//  Created by bob on 11/4/09.
//  Copyright __MyCompanyName__ 2009. All rights reserved.
//

#import "iPhonePgAppDelegate.h"
#import "iPhonePgViewController.h"
#include "libpq-fe.h"
@implementation iPhonePgAppDelegate

@synthesize window;
@synthesize viewController;


- (void)applicationDidFinishLaunching:(UIApplication *)application {
    const char *conninfo;
    PGconn     *conn;
    PGresult   *res;



    conninfo = "host = 192.168.1.5 dbname = dev user=postgres password=zzzzz";

    /* Make a connection to the database */
    conn = PQconnectdb(conninfo);
    res = PQexec(conn, "INSERT INTO public.junk(junk_data) VALUES('HELLO');");
    if (PQstatus(conn) != CONNECTION_OK)
    {
        fprintf(stderr, "Connection to database failed: %s",
        PQerrorMessage(conn));
    }
    PQclear(res);
    PQfinish(conn);

    [window addSubview:viewController.view];
    [window makeKeyAndVisible];
}


- (void)dealloc {
    [viewController release];
    [window release];
    [super dealloc];
}
Here is the output from my build attempt that is showing an error.
Keep in mind I have the equivalent Mac version of this app connecting
to PostgreSQL just fine. The only real difference is the project type
of the apps, Mac app vs iPhone app. So I feel pretty good about me not
doing something that is obviously wrong. I'm on Snow Leopard with
Xcode 3.2 using libpq compiled for i386 from PostgreSQL 8.4.1 source.

Ld build/Debug-iphonesimulator/iPhonePg.app/iPhonePg normal i386
cd /Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg
setenv MACOSX_DEPLOYMENT_TARGET 10.5
setenv PATH
"/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2
-arch i386 -isysroot
/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator3.0.sdk
-L/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/build/Debug-iphonesimulator
-L../../../../mylibs
-L/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg
-L/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/../../../../mylibs
-F/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/build/Debug-iphonesimulator
-filelist
/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/build/iPhonePg.build/Debug-iphonesimulator/iPhonePg.build/Objects-normal/i386/iPhonePg.LinkFileList
-mmacosx-version-min=10.5 -framework Foundation -framework UIKit
-framework CoreGraphics
/Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/../../../../mylibs/libpq.i386
-o /Users/bob/Documents/Programming/PragProgrammerIphoneSDK/iPhonePg/build/Debug-iphonesimulator/iPhonePg.app/iPhonePg

Undefined symbols:
  "_fopen$UNIX2003", referenced from:
      _parseServiceInfo in libpq.i386(fe-connect.o)
      _PasswordFromFile in libpq.i386(fe-connect.o)
ld: symbol(s) not found
collect2: ld returned 1 exit status

Any help would be greatly appreciated.

Thanks
Bob

hi bob,

> Undefined symbols:
> "_fopen$UNIX2003", referenced from:
>     _parseServiceInfo in libpq.i386(fe-connect.o)
>     _PasswordFromFile in libpq.i386(fe-connect.o)
> ld: symbol(s) not found
> collect2: ld returned 1 exit status
>
> Any help would be greatly appreciated.

hm, fopen is a standard c (libSystem) function. make shure you
have linked your library (libpq) against the same versions of
standard libraries as you try with your iphone-app.

check your linker options, specially -isysroot.

you can check later to which libSystem your lib or app was built
with: otool -L <LibOrApp>

regards, jan otto

Thanks Jan that was the issue. The SDK that my app was using for the
simulator build was  was 10.5 while the my compile of libpq was using
10.6. Once I forced libpq to compile with 10.5 all my problems went
away. Thanks for your help I appreciate it.

On Mon, Nov 9, 2009 at 8:40 AM, Jan Otto <asche@me.com> wrote:
> hi bob,
>
>> Undefined symbols:
>> "_fopen$UNIX2003", referenced from:
>>    _parseServiceInfo in libpq.i386(fe-connect.o)
>>    _PasswordFromFile in libpq.i386(fe-connect.o)
>> ld: symbol(s) not found
>> collect2: ld returned 1 exit status
>>
>> Any help would be greatly appreciated.
>
> hm, fopen is a standard c (libSystem) function. make shure you
> have linked your library (libpq) against the same versions of
> standard libraries as you try with your iphone-app.
>
> check your linker options, specially -isysroot.
>
> you can check later to which libSystem your lib or app was built
> with: otool -L <LibOrApp>
>
> regards, jan otto
>