Possibility to add dlinfo() to dlfcn.h?

Corinna Vinschen corinna-cygwin@cygwin.com
Thu Feb 2 15:26:00 GMT 2012


On Feb  2 09:52, Ryan Johnson wrote:
> Hi all,
> 
> Before I go off hacking code, is there a particular reason dlinfo()
> is missing from cygwin's dlfcn.h, other than SHTDI? I know it's not

I guess it's a case of SHTNI, too, with N == notice or need.  After
all, it doesn't even have a man page.

> strictly a posix function, but it is present in the linux systems I
> have access to and can be rather handy. I considered parsing
> /proc/$$/maps, but that doesn't guarantee the module is actually
> loaded (as opposed to merely mmapped).
> 
> Based on past tangles with cygwin's underbelly I would think some
> boilerplate surrounding a call to GetLoadedModules() would suffice.

Not sure about that.  What do you want this function for?  What's
your use case?  Reading the info in dlfcn.h, I don't see how this
function can be useful under Windows:

  RTLD_DI_LMID          We have no namespace ID
  RTLD_DI_LINKMAP       Possible, except l_ld doesn't mean anything
  RTLD_DI_CONFIGADDR    ?
  RTLD_DI_SERINFO	Would return the DLL search path.
  RTLD_DI_SERINFOSIZE   Ditto, sizeof
  RTLD_DI_ORIGIN        There is no $ORIGIN
  RTLD_DI_PROFILENAME   ?
  RTLD_DI_PROFILEOUT    ?
  RTLD_DI_TLS_MODID     We have no PT_TLS segment, and no TLS relocations.
  RTLD_DI_TLS_DATA      Ditto

Looks like only RTLD_DI_LINKMAP and RTLD_DI_SERINFO{SIZE} may be of
any use.  But still, what's your use case?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat



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