llvm dev - Jun 2010 - [LLVMdev] having troubles mixing ExecutionEngine::runStaticConstructorsDestructors() and Linker::LinkModules()

The use case is to create a module A, JIT from it, then extend the module with
new code (create a new module B and use Linker::LinkModules() to merge into A,
and be able to JIT the new symbols).  This appears to work ok, except that
static constructors are giving me a headache.

Generally, I start like this:

Create module A (e.g. via Clang, LLVM API etc.)
EE->addModule(A);
EE->runStaticConstructorsDestructors(A, false);
EE->getPointerToFunction(A->getFunction(funcname));


Then, create module B (e.g. via Clang, LLVM API etc.) to be used to extend
module A. I've tried out the following sequences of calls to get this to
work with statics, with the following difficulties:

Option 1);

Linker::LinkModules(A, B);								
EE->runStaticConstructorsDestructors(B, false);			// <- note, Module B
--> llvm error Program used external function
'__cxx_global_initialization' which could not be resolved!

Presumably because module B no longer exists.

Option 2);

Linker::LinkModules(A, B);								
EE->runStaticConstructorsDestructors(A, false);			// <- note, Module A
EE->getPointerToFunction(A->getFunction(funcname));	 // e.g. funcname was
originally defined in module A

Usually leads to a crash - apparently the statics originally defined in module A
get called twice, while the statics defined in module B never get called.

Option 3);

EE->runStaticConstructorsDestructors(B, false);			// appears to trigger
B's statics (even though B is not in EE yet...)
Linker::LinkModules(A, B);								
EE->getPointerToFunction(A->getFunction(funcname));	 // e.g. funcname was
originally defined in module B but now in A

The problem is that the code emitted in the last getPointerToFunction() does not
appear to use the statics initialized from module B... presumably because
__cxx_global_initialization was already defined.


Is there any possible solution for what I want to do? Or should I always keep
the modules separate (not use LinkModules()) for this situation?

Thanks in advance