Can I get the internal name of a package at runtime?

[Daniel Gröber]

Hi,

I think you might be interrested in my rts-loader package,
particularly the [mkSymbol function](https://github.com/DanielG/rts-loader/blob/master/System/Loader/RTS.hs#L275).

It should demonstrate how you can construct the symbol names for
dynamic loading and how to coax the information needed out of Cabal,
see the README and the rest of the source.

--Daniel

On Sat, Oct 14, 2017 at 09:59:03PM +0200, MarLinn wrote:
> That sounds reasonable, but also like there *can not be* a way to obtain
> that hash at runtime. And therefore, no way to discover the true package
> name.
> 
> Which in turn makes discovery and loading of plug-ins a bit harder. Well, I
> guess it's for a good reason so I'll have to work around it. Good to know.
> 
> Thanks for helping out!
> 
> Cheers,
> MarLinn
> 
> 
> On 2017-10-14 20:11, Brandon Allbery wrote:
> > On Sat, Oct 14, 2017 at 12:48 PM, MarLinn <monkleyon at gmail.com
> > <mailto:monkleyon at gmail.com>> wrote:
> > 
> >     So the "actual" package name seems to be
> >     "Plugin-0.0.0.0-2QaFQQzYhnKJSPRXA7VtPe".
> >     That leaves the random(?) characters behind the version number to
> >     be explained.
> > 
> > 
> > ABI hash of that specific package build, which is needed because
> > compiling with different optimization levels etc. will change what part
> > of the internals gets exposed in the .hi file for inlining into other
> > modules; mismatches there lead to *really* weird behavior. (If you're
> > lucky, it'll "just" be a type mismatch in code you didn't write, because
> > it came from the .hi file. If unlucky, it compiles but dumps core at
> > runtime.)
> > 
> > -- 
> > brandon s allbery kf8nh sine nomine associates
> > allbery.b at gmail.com <mailto:allbery.b at gmail.com> ballbery at sinenomine.net
> > <mailto:ballbery at sinenomine.net>
> > unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net
> 
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