LLVM API: correct way to create/dispose - llvm

Question

I'm attempting to implement a simple JIT compiler using the LLVM C API. So far, I have no problems generating IR code and executing it, that is: until I start disposing objects and recreating them.
What I basically would like to do is to clean up the JIT'ted resources the moment they're no longer used by the engine. What I'm basically attempting to do is something like this:
while (true)
{
// Initialize module & builder
InitializeCore(GetGlobalPassRegistry());
module = ModuleCreateWithName(some_unique_name);
builder = CreateBuilder();
// Initialize target & execution engine
InitializeNativeTarget();
engine = CreateExecutionEngineForModule(...);
passmgr = CreateFunctionPassManagerForModule(module);
AddTargetData(GetExecutionEngineTargetData(engine), passmgr);
InitializeFunctionPassManager(passmgr);
// [... my fancy JIT code ...] --** Will give a serious error the second iteration
// Destroy
DisposePassManager(passmgr);
DisposeExecutionEngine(engine);
DisposeBuilder(builder);
// DisposeModule(module); //--> Commented out: Deleted by execution engine
Shutdown();
}
However, this doesn't seem to be working correctly: the second iteration of the loop I get a pretty bad error...
So to summarize: what's the correct way to destroy and re-create the LLVM API?

Answer 1

Posting this as Answer because the code's too long. If possible and no other constraints, try to use LLVM like this. I am pretty sure the Shutdown() inside the loop is the culprit here. And I dont think it would hurt to keep the Builder outside, too. This reflects well the way I use LLVM in my JIT.
InitializeCore(GetGlobalPassRegistry());
InitializeNativeTarget();
builder = CreateBuilder();
while (true)
{
// Initialize module & builder
module = ModuleCreateWithName(some_unique_name);
// Initialize target & execution engine
engine = CreateExecutionEngineForModule(...);
passmgr = CreateFunctionPassManagerForModule(module);
AddTargetData(GetExecutionEngineTargetData(engine), passmgr);
InitializeFunctionPassManager(passmgr);
// [... my fancy JIT code ...] --** Will give a serious error the second iteration
// Destroy
DisposePassManager(passmgr);
DisposeExecutionEngine(engine);
}
DisposeBuilder(builder);
Shutdown();

Answer 2

/* program init */
LLVMInitializeNativeTarget();
LLVMInitializeNativeAsmPrinter();
LLVMInitializeNativeAsmParser();
LLVMLinkInMCJIT();
ctx->context = LLVMContextCreate();
ctx->builder = LLVMCreateBuilderInContext(ctx->context);
LLVMParseBitcodeInContext2(ctx->context, module_template_buf, &module) // create module
do IR code creation
{
function = LLVMAddFunction(ctx->module, "my_func")
LLVMAppendBasicBlockInContext(ctx->context, ...
LLVMBuild...
...
}
optional optimization
{
LLVMPassManagerBuilderRef pass_builder = LLVMPassManagerBuilderCreate();
LLVMPassManagerBuilderSetOptLevel(pass_builder, 3);
LLVMPassManagerBuilderSetSizeLevel(pass_builder, 0);
LLVMPassManagerBuilderUseInlinerWithThreshold(pass_builder, 1000);
LLVMPassManagerRef function_passes = LLVMCreateFunctionPassManagerForModule(ctx->module);
LLVMPassManagerRef module_passes = LLVMCreatePassManager();
LLVMPassManagerBuilderPopulateFunctionPassManager(pass_builder, function_passes);
LLVMPassManagerBuilderPopulateModulePassManager(pass_builder, module_passes);
LLVMPassManagerBuilderDispose(pass_builder);
LLVMInitializeFunctionPassManager(function_passes);
for (LLVMValueRef value = LLVMGetFirstFunction(ctx->module); value;
value = LLVMGetNextFunction(value))
{
LLVMRunFunctionPassManager(function_passes, value);
}
LLVMFinalizeFunctionPassManager(function_passes);
LLVMRunPassManager(module_passes, ctx->module);
LLVMDisposePassManager(function_passes);
LLVMDisposePassManager(module_passes);
}
optional for debug
{
LLVMVerifyModule(ctx->module, LLVMAbortProcessAction, &error);
LLVMPrintModule
}
if (LLVMCreateJITCompilerForModule(&ctx->engine, ctx->module, 0, &error) != 0)
my_func = (exec_func_t)(uintptr_t)LLVMGetFunctionAddress(ctx->engine, "my_func");
LLVMRemoveModule(ctx->engine, ctx->module, &ctx->module, &error);
LLVMDisposeModule(ctx->module);
LLVMDisposeBuilder(ctx->builder);
do
{
my_func(...);
}
LLVMDisposeExecutionEngine(ctx->engine);
LLVMContextDispose(ctx->context);
/* program finit */
LLVMShutdown();