Re: lt_dlerror() and error output...

[Eric Bleher]

Have anybody read my pb ?

> I'm using libtool version 1.4.2 (1.922.2.53
> 2001/09/11
> 03:18:52) with automake 1.6 / autoconf 2.53 unter
> suse
> linux 7.2.
> 
> I want to use the libltdl librairie instead of
> standard linux dlopen... utilities.
> 
> But the lt_dlerror() function seems not to work so
> good as dlerror() function.
> 
> Here is a part if my source code ("new" version) :
> 
> 
> // init
> if (lt_dlinit() != 0) 
>    { fprintf(stderr,"%s\n", lt_dlerror()); exit(1);
> }
> 
> // open
> lt_dlhandle libhandle = lt_dlopen(libDir + "/" +                      
> 
> tmpLibName);
> if(!libhandle)  
>    throw DynLibError(string("Error opening library
> ")
> +             libName + ":\n  " +  lt_dlerror() );
> 
> cerr << libDir + "/" + tmpLibName << endl;
> cerr << "1 : " << createFuncName.c_str() << endl;
> typedef BaseInspector *(*CreateFunc)(const char *,    
> 
> Defaults *, InspectorHandler *);
> cerr << libDir + "/" + tmpLibName << endl;
> cerr << "1 : " << createFuncName.c_str() << endl;
> lt_ptr ptr = lt_dlsym(libhandle,                                      
> createFuncName.c_str());
> const char * err = lt_dlerror();
> cerr << "2 : " << ptr << endl;
>  
> if (!ptr || err)
>   throw DynLibError(string("Error finding function
> ")
> +      createFuncName + " in " + libName + ":  " + 
> err);  
> 
> CreateFunc createfunc = (CreateFunc)ptr;
> 
> 
> And this code says that :
> Parsing "definitions/inspectorsDiskMono"
> /.../lib/libDiskLoader.so
> 1 : createDiskLoaderMono
> 2 : 0x40043ef0
> While parsing "definitions/inspectorsDiskMono" (line
> 3):
>   Error finding function createDiskLoaderMono in
> libDiskLoader.so:  unknown error
> Parsing "definitions/inspectorsHpn"
> /.../lib/libScaleInspector.so
> 1 : createScaleInspector
> 2 : 0x415b5710
> While parsing "definitions/inspectorsHpn" (line 3):
>   Error finding function createScaleInspector in
> libScaleInspector.so:  unknown error
> No definition files parsed - aborting
> 
> 
> The pb is the "unknown error" when there is none !!
> Here is the program not launched.
> 
> 
> The old version was :
> 
> void *libhandle = dlopen((libDir + "/" +
> tmpLibName), 
>               RTLD_NOW | RTLD_GLOBAL);
> err = dlerror();
> if( !libhandle )
>      throw DynLibError(string("Error opening library
> ")            + libName + ":\n  " + err);
> 
> typedef BaseInspector *(*CreateFunc)(const char *,    
> 
> Defaults *, InspectorHandler *);
> CreateFunc createfunc = (CreateFunc) 
>            dlsym(libhandle, createFuncName.c_str());
> err = dlerror();
> if (err) 
>    throw DynLibError(string("Error finding function
> ")
>     + createFuncName + " in " + libName + ":  " +
> err);
> 
> 
> 
> which said that :
> Parsing "definitions/inspectorsDiskMono"
> Parsing "definitions/inspectorsHpn"
> While parsing "definitions/inspectorsHpn" (line 5):
>   Error opening library libHpnInspector.so:
>
/home/bleher/qt-programming/LabFramework/lib/libHpnInspector.so:
> undefined symbol:
> __vt_23HpnTimeDelayBoxesWidget.12QPaintDevice
> 
> Here my application launch without the Hpn librarie
> 
> 
> With my "new" version, I've also so tried :
> ...
> lt_ptr ptr = lt_dlsym(libhandle,                      
> createFuncName.c_str());
> cerr << "2 : " << ptr << endl;
> if (!ptr)
>     throw DynLibError(string("Error finding function
> ")    + createFuncName + " in " + libName + ":  " +           
> lt_dlerror());  
> CreateFunc createfunc = (CreateFunc)ptr;
> 
> Which said that :
> Parsing "definitions/inspectorsDiskMono"
>
/home/bleher/qt-programming/LabFramework/lib/libDiskLoader.so
> 1 : createDiskLoaderMono
> 2 : 0x40043ef0
> Parsing "definitions/inspectorsHpn"
>
/home/bleher/qt-programming/LabFramework/lib/libScaleInspector.so
> 1 : createScaleInspector
> 2 : 0x415e3710
>
/home/bleher/qt-programming/LabFramework/lib/libHpnInspector.so
> 1 : createHpnInspector
> Segmentation fault
> 
> And my program crash
> 
> 
> The question is : how does I use lt_dlerror() that I
> would read the same output as in dlerror() version
> ??
> 
> 
> I've this pb only when there is an error in my
> librairie. Here are the output when I use a "good"
> librairie :
> 
> - old version - 
> Parsing "definitions/inspectorsDiskMono"
> Parsing "definitions/inspectorsContrast"
> 
> - new version (b) - 
> Parsing "definitions/inspectorsDiskMono"
>
/home/bleher/qt-programming/LabFramework/lib/libDiskLoader.so
> 1 : createDiskLoaderMono
> 2 : 0x40043ef0
> Parsing "definitions/inspectorsContrast"
>
/home/bleher/qt-programming/LabFramework/lib/libContrastInspector.so
> 1 : createContrastInspector
> 2 : 0x415e4f70
> 
> - new version (a) (with const char * err) -
> Parsing "definitions/inspectorsDiskMono"
>
/home/bleher/qt-programming/LabFramework/lib/libDiskLoader.so
> 1 : createDiskLoaderMono
> 2 : 0x40043ef0
> While parsing "definitions/inspectorsDiskMono" (line
> 3):
>   Error finding function createDiskLoaderMono in
> libDiskLoader.so:  unknown error
> Parsing "definitions/inspectorsContrast"
>
/home/bleher/qt-programming/LabFramework/lib/libContrastInspector.so
> 1 : createContrastInspector
> 2 : 0x415b6f70
> While parsing "definitions/inspectorsContrast" (line
> 3):
>   Error finding function createContrastInspector in
> libContrastInspector.so:  unknown error
> No definition files parsed - aborting
> 
> 
> 
> In both cases, the program launch with the
> librairie,
> but not in the last case.
> 
> I precise that I've read the all GNU libtool docu
> and
> search in the download version of mailing list (the
> 6MB data), but I haven't found anything concerning
> my
> problem. I've search in google and found similar
> mails
> from others users but old (2000) and without
> solution.
> The error may be in ltdl.c ??
> 
> Thanks for your help...
> 
> I repeat my question : how does I use lt_dlerror()
> that I could read the same output as in dlerror()
> version when an error (such as "symbol not found")
> appear ?
> 
=== message truncated === 

___________________________________________________________
Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en français !
Yahoo! Mail : http://fr.mail.yahoo.com