Re: ghc api and .o files

On Fri, Sep 14, 2012 at 6:22 PM, Brandon Allbery wrote:

On Fri, Sep 14, 2012 at 1:31 AM, Evan Laforge wrote:

...

Relatedly, I've noticed that OS X is forgiving when you don't link in a needed object. It will let me run code, but if I call a function that's not linked in I get a crash. However, linux immediately prints "unknown symbol `etc.'". The OS X behaviour is more convenient because it's easy to avoid calling the missing functions, and difficult to figure out how to cut all the dependencies so they're not needed, but the linux way is certainly safer. Does anyone know why this difference exists? Just curious.

Because the system dynamic loader has different defaults. OS X defaults to a lazier lookup than Linux does; Linux is actually somewhat lazy about it, just not as lazy as OS X. Unfortunately I only know how to make them both stricter, not lazier.

("man ld.so" on Linux, "man dyld" on OS X, for the details)

I thought ghc uses its own homegrown loader, not the system one? I.e. ghci loads .o files, not .dyld or .so.