[Ekiga-devel-list] Build error with pwlib head and gcc-3.4.6

[Luc Saillard <luc saillard org>]

Hi,

 I try to build ekiga snapshot (from two days ago) and it failed when linking
a program. Building the pwlib library (and opal) reports no error, but failed on a
simple program like this:

      /* Override any gcc2 internal prototype to avoid an error.  */
      #ifdef __cplusplus
      extern "C"
      #endif
      /* We use char because int might match the return type of a gcc2
         builtin and then its argument prototype would still apply.  */
      char read ();
      int main ()
      {
        read ();
        return 0;
      }


# g++-3.4 t.c -lpt_linux_x86_r -Llib 
lib/libpt_linux_x86_r.so: undefined reference to `PVideoOutputDevice::Stop()'
lib/libpt_linux_x86_r.so: undefined reference to `PVideoOutputDevice::Start()'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoInputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoOutputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoOutputDeviceRGB'
lib/libpt_linux_x86_r.so: undefined reference to `VTT for PVideoChannel'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoChannel'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoFrameInfo'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoFrameInfo'
lib/libpt_linux_x86_r.so: undefined reference to `PVideoDevice::SetFrameSizeConverter(unsigned int, unsigned int, int)'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoInputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoOutputDevice'
collect2: ld a retourné 1 code d'état d'exécution

I can build and link with gcc-4.1 from debian sid without problem, but i can't
upgrade my gcc. My c++ knownledges with pure and virtual fonctions is far from
good, but perhaps this link will help:

        http://centibyte.org/me/obscure-errors.html

I've try to find where the virtual function is missing but only correct the
first one with this patch:

# HG changeset patch
# User "Luc Saillard <luc saillard org>"
# Date 1191336108 -7200
# Node ID 8e16f0aafe552ff2c1ad5bb7f64650187e1886dd
# Parent  11a6f733e22458facaad72e595410f5a5038cb1c
remove some errors with g++-3.4

diff -r 11a6f733e224 -r 8e16f0aafe55 include/ptlib/videoio.h
--- a/include/ptlib/videoio.h	Tue Oct 02 16:40:21 2007 +0200
+++ b/include/ptlib/videoio.h	Tue Oct 02 16:41:48 2007 +0200
@@ -815,15 +815,15 @@ class PVideoOutputDevice : public PVideo
 
     /**Close the device.
       */
-    virtual BOOL Close() { return TRUE; }
+    virtual BOOL Close();
 
     /**Start the video device I/O display.
       */
-    virtual BOOL Start() { return TRUE; }
+    virtual BOOL Start();
 
     /**Stop the video device I/O display.
       */
-    virtual BOOL Stop() { return TRUE; }
+    virtual BOOL Stop();
 
     /** Is the device a camera, and obtain video
      */
diff -r 11a6f733e224 -r 8e16f0aafe55 src/ptlib/common/videoio.cxx
--- a/src/ptlib/common/videoio.cxx	Tue Oct 02 16:40:21 2007 +0200
+++ b/src/ptlib/common/videoio.cxx	Tue Oct 02 16:41:48 2007 +0200
@@ -1173,6 +1173,20 @@ BOOL PVideoOutputDevice::CanCaptureVideo
   return FALSE;
 }
 
+BOOL PVideoOutputDevice::Close()
+{
+  return TRUE;
+}
+
+BOOL PVideoOutputDevice::Start()
+{
+  return TRUE;
+}
+
+BOOL PVideoOutputDevice::Stop()
+{
+  return TRUE;
+}
 
 BOOL PVideoOutputDevice::GetPosition(int &, int &) const
 {

And now i got this when linking the little program:

# g++-3.4 t.c -lpt_linux_x86_r -Llib 
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoInputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoOutputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoOutputDeviceRGB'
lib/libpt_linux_x86_r.so: undefined reference to `VTT for PVideoChannel'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoChannel'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoFrameInfo'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoFrameInfo'
lib/libpt_linux_x86_r.so: undefined reference to `PVideoDevice::SetFrameSizeConverter(unsigned int, unsigned int, int)'
lib/libpt_linux_x86_r.so: undefined reference to `typeinfo for PVideoInputDevice'
lib/libpt_linux_x86_r.so: undefined reference to `vtable for PVideoOutputDevice'
collect2: ld a retourné 1 code d'état d'exécution

Any idea to fix the problem ?

Luc