On Thu, May 20, 2010 at 1:07 PM, Brandon S. Allbery KF8NH
On May 20, 2010, at 06:23 , Simon Marlow wrote:
On 18/05/2010 17:48, John Lato wrote:
From: Simon Marlow
But currently there is one problem with "GhcShared=YES": with this option, the stage-2 compiler gets linked dynamically but the corresponding inplace shell wrapper does not set (DY)LD_LIBRARY_PATH, thus ./inplace/bin/ghc-stage2 doesn't run at all. I could work around this by manually symlinking all the dynamic libraries to ./inplace/lib and setting (DY)LD_LIBRARY_PATH to there, but obvisouly there should be a solution better than this.
On Linux we link the binary using -rpath (I know OS X doesn't have -rpath). This is another issue we need to resolve before we can switch to a dynamically-linked GHCi.
When you say OSX doesn't have -rpath, do you mean there's some problem with using -rpath on OSX? I have code that links to a 3rd-party library (libcudart.dylib) at runtime and it seems to use -rpath fine. This is with ghc-6.12.1.
It was my understanding that OS X doesn't have -rpath from reading
http://hackage.haskell.org/trac/ghc/wiki/SharedLibraries/Management
and from what I remember Mac people saying in the past. Or maybe they were just saying that -rpath is not the right thing on OS X because libraries themselves have paths baked in.
The latter. Also, I'd recommend DYLD_FALLBACK_LIBRARY_PATH per Apple recommendations, as you can otherwise get weird results.
Apparently -rpath was only added in 10.5, so the former was previously true also. According to the ld manpage, -rpath only has an effect when the library's load path begins with @rpath/, which seems to break the usual OS X loading scheme so you then have to use -rpath. According to the dyld docs, it looks like -rpath is meant to be used as a last resort when other mechanisms aren't feasible. In particular, "The use of @rpath is most useful when you have a complex directory structure of programs and dylibs which can be installed anywhere, but keep their relative positions." [1] I suppose I'd agree that it's best avoided on OSX if it can be helped. John [1] http://developer.apple.com/mac/library/documentation/Darwin/Reference/ManPag...