[lldb-dev] Testing MCJIT (vs. standard JIT)

[Greg Clayton]

On Aug 29, 2013, at 11:57 AM, Ed Maste <emaste at freebsd.org> wrote:

> source/Expression/ClangExpressionParser.cpp currently has
> 
> #if defined(__FreeBSD__)
> #define USE_STANDARD_JIT
> #endif
> 
> which then includes llvm/ExecutionEngine/JIT.h instead of
> llvm/ExecutionEngine/MCJIT.h.
> 
> It looks like this has evolved over time from being the default on all
> platforms, to !defined(__APPLE__), to the current FreeBSD-only case.
> I'm currently tracking down a number of unit test failures on FreeBSD,
> but the results seem consistent with or without the USE_STANDARD_JIT
> define.

Yes, we should probably switch to using MCJIT for all platforms by default.
> 
> I'd like to enable MCJIT on FreeBSD so that any testing is with the
> most commonly used code.  Is there a simple case I can use to confirm
> that MCJIT works as expected, or known dependencies to investigate?


Just launch a program and try to run:

(lldb) expr (void *)malloc(123)

This will tell you if simple things are working.