Re: [xml] xmlParseMemory() and xmlParseDTD()

[Gary Pennington <Gary Pennington sun com>]

Daniel Veillard wrote:

> On Wed, Mar 06, 2002 at 01:07:54PM +0100, MDC A. wrote:
>
> >  xmlParserError(0x160840, 0x122cf0, 0x1646c8, 0x0,
> > 0x0, 0x164afd)
>
>    xmlParserError calls the xmlGenericError routine which is initialized
> to xmlGenericErrorDefaultFunc, with the default xmlGenericErrorContext which
> is initialized to NULL.
>
> >   xmlGenericErrorDefaultFunc(0x0, 0x12fcf8, 0x5,
> > 0xfffffff8,
> > 0x44, 0x1646b8)
>
>  So that call is correct. 
>  BUT xmlGenericErrorDefaultFunc() code is:
>
> ---------------
> void
> xmlGenericErrorDefaultFunc(void *ctx ATTRIBUTE_UNUSED, const char *msg, ...) {
>    va_list args;
>
>    if (xmlGenericErrorContext == NULL)
>         xmlGenericErrorContext = (void *) stderr;
>
>    va_start(args, msg);
>    vfprintf((FILE *)xmlGenericErrorContext, msg, args);
>    va_end(args);
> }
> ---------------
>
>  Unless stderr == NULL in Solaris which would be really really strange,
>
> > vfprintf(0x0, 0xffbef0e4, 0xfeabf9b4, 0x8, 0x12fcf8,
> > 0x1646c8)
>
>  I really don't see how the first argument to vfprintf being passed can be
> NULL !
>
> > which is the problem here?
>
>  I really don't know there is something really really strange here !
>
> > How can the problem be solved?
>
>  Take a debugger and check by single stepping, possibly looking at
> the assembly generated. I don't understand how the first argument of the
> call can be NULL ! Or someone else on Solaris can reproduce your problem
> and check it for you, sorry I can't ...
>
> Daniel
Hi,

To cut a long story short, I think this is a problem to do with the 
configure script. The linkage to -lpthread wasn't specified and so if 
your application was single threaded and you built libxml2 for 
multi-threaded use, failures of this nature would be caused.

This was fixed before I reported it, but I think that it was only fixed 
in 2.4.16.

You can check by seeing if libxml2.so is linked to -lpthread, e.g.:

bash-2.03$ ldd /usr/local/libxml/sparc/lib/libxml2.so
       libpthread.so.1 =>       /usr/lib/libpthread.so.1
       libz.so.1 =>     /usr/lib/libz.so.1
       libm.so.1 =>     /usr/lib/libm.so.1
       libsocket.so.1 =>        /usr/lib/libsocket.so.1
       libnsl.so.1 =>   /usr/lib/libnsl.so.1
       libc.so.1 =>     /usr/lib/libc.so.1
       libdl.so.1 =>    /usr/lib/libdl.so.1
       libmp.so.2 =>    /usr/lib/libmp.so.2
       libthread.so.1 =>        /usr/lib/libthread.so.1
       /usr/platform/SUNW,Ultra-60/lib/libc_psr.so.1
bash-2.03$

If it isn't linked to -lpthread, then it's broken for use with single 
threaded apps.

The easy answer is to upgrade your version of libxml2 to use the latest 
set of binaries that I ship from http://garypennington.net/libxml2/. 
Alternatively, if you use an older version of Solaris, download the 
source for 2.4.16 and build it.

Gary

--
Gary Pennington
Solaris Kernel Development,
Sun Microsystems
Gary Pennington sun com