Mailing-List: contact cygwin-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin AT sources DOT redhat DOT com
X-Envelope-Sender-Is: Andrej DOT Borsenkow AT mow DOT siemens DOT ru (at relayer david.siemens.de)
From: "Andrej Borsenkow" <Andrej DOT Borsenkow AT mow DOT siemens DOT ru>
To: <Cygwin AT sourceware DOT cygnus DOT com>
Subject: Some question about DLL names/export names
Date: Mon, 14 Aug 2000 17:44:17 +0400
Message-ID: <000b01c005f5$bdff5e90$21c9ca95@mow.siemens.ru>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="koi8-r"
Content-Transfer-Encoding: 7bit
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0)
Importance: Normal
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400

When DLL is created, there is a parameter --dllname thet is recorded into DLL.
I first thought was, that this name is used for import lists as well, but it
looks, like in this case compiler is still using DLL _file_ name with all
leading directories stripped.

My problem is as following:

assuming I have dir1/foo.dll, dir1/bar.dll and dir2/foo.dll. I also have a
a.exe that loads DLLs using dlopen()/dlsym(). dir1/bar.dll depends on
dir1/foo.dll (that is, it is directly using functions and/or variables from
dir1/foo.dll) and is built with it. More precisely:

dllwrap --dllname dir1_foo -o $dest/dir1/foo.dll $src/dir1/foo.o
dllwrap --dllname dir1_bar -o $dest/dir1/bar.dll $src/dir1/bar.o
$dest/dir1/foo.dll
dllwrap --dllname dir2_foo -o $dest/dir2/foo.dll $src/dir2/foo.o

My problem is, can it happen that

- a.exe first loads dir2/foo.dll
- then it loads dir1/bar.dll
- bar.dll tries to resolve reference to objects from foo.dll (note, that in
import list there is no reference to --dllname or full path), finds already
loaded instance of WRONG foo.dll and either gives an error or resolves wrong
symbol.

May be, I have to use different compiler options?

To clarify what I mean:

objdump dir/foo1.dll:
...
There is an export table in .edata at 0x6a4c4000

The Export Tables (interpreted .edata section contents)

Export Flags                    0
Time/Date stamp                 3997eee8
Major/Minor                     0/0
Name                            00004028 dir/foo1.dll
...
This is the name I specified with --dllname option

objdump dir/foo2.dll
...
        DLL Name: foo1.dll
        vma:  Hint/Ord Member-Name
        5158        0  foo1
        5160        1  foo1_print_foo1
        The Import Address Table is identical
...
note, that name used in import table is just foo1.dll; the same if I give
`--dllname foobar' option.

-andrej

Have a nice DOS!
B >>


--
Want to unsubscribe from this list?
Send a message to cygwin-unsubscribe AT sourceware DOT cygnus DOT com