[LLVMdev] Please help with LLVM C++ integration

[kirill havok]

Many thanks to all, I really forgot to link with X86TargetMachine.obj
file (((((, now this code works perfect. )))))
Sincerely, Kirill

int some_test_func( int ){
	std::cout << "!!!!" << std::endl;
	return 8848;
}

int _tmain(int argc, _TCHAR* argv[]){

	Module *M = new Module("test");
	ExistingModuleProvider* MP = new ExistingModuleProvider(M);
	ExecutionEngine* EE = ExecutionEngine::create(MP, false);

	std::vector<const Type *> func_args;
	func_args.push_back(Type::Int32Ty);
	FunctionType * func_type = FunctionType::get(Type::Int32Ty, func_args, false);
	Function * my_function = Function::Create( func_type,
Function::ExternalLinkage, "some_test_func", M );
	EE->addGlobalMapping( my_function, (void*)&some_test_func );

	Function *FooF = cast<Function>(M->getOrInsertFunction("foo",
Type::Int32Ty, (Type *)0));
	BasicBlock * BB = BasicBlock::Create("EntryBlock", FooF);
	Value *Ten = ConstantInt::get(Type::Int32Ty, 10);
	CallInst *Add1CallRes = CallInst::Create(my_function, Ten,
"some_test_func", BB);
	Add1CallRes->setTailCall(true);

	ReturnInst::Create(Add1CallRes, BB);

	std::cout << "We just constructed this LLVM module:\n\n" << *M;
	std::cout << "\n\nRunning foo: " << std::flush;

	std::vector<GenericValue> noargs;
	GenericValue gv = EE->runFunction(FooF, noargs);

	std::cout << "Result: " << gv.IntVal.toStringUnsigned(10) << "\n";
	return 0;
}


2008/8/20 Rob Grapes <Rob.Grapes at ur.co.nz>:
> Hi Kirill,
>
> Don't forget to add X86TargetMachine.obj (add to Additional Dependencies in Linker options, if you are using MSVS) otherwise LLVM will try and use Interpreter instead of JIT.
>
> Hope this helps,
>
> Rob.
>
>> -----Original Message-----
>> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu]
>> On Behalf Of kirill havok
>> Sent: Wednesday, August 20, 2008 8:32 AM
>> To: LLVM Developers Mailing List
>> Subject: Re: [LLVMdev] Please help with LLVM C++ integration
>>
>> Hi Gordon,
>> I wrote a small example, but while running I get an error("Tied to
>> execute an unknown external function"), where I am wrong?
>>
>> Thanks in advance.
>> Kirill.
>>
>> int some_test_func( int ){
>>         std::cout << "!!!!" << std::endl;
>>         return 8848;
>> }
>>
>> int _tmain(int argc, _TCHAR* argv[]){
>>
>>         Module *M = new Module("test");
>>         ExistingModuleProvider* MP = new ExistingModuleProvider(M);
>>         ExecutionEngine* EE = ExecutionEngine::create(MP, false);
>>
>>         std::vector<const Type *> func_args;
>>         func_args.push_back(Type::Int32Ty);
>>         FunctionType * func_type = FunctionType::get(Type::Int32Ty,
>> func_args, false);
>>         Function * my_function = Function::Create( func_type,
>> Function::ExternalLinkage, "some_test_func", M );
>>         EE->addGlobalMapping( my_function, (void*)&some_test_func );
>>
>>         Function *FooF = cast<Function>(M->getOrInsertFunction("foo",
>> Type::Int32Ty, (Type *)0));
>>         BasicBlock * BB = BasicBlock::Create("EntryBlock", FooF);
>>         Value *Ten = ConstantInt::get(Type::Int32Ty, 10);
>>         CallInst *Add1CallRes = CallInst::Create(my_function, Ten,
>> "some_test_func", BB);
>>         Add1CallRes->setTailCall(true);
>>
>>         ReturnInst::Create(Add1CallRes, BB);
>>
>>         std::cout << "We just constructed this LLVM module:\n\n" << *M;
>>         std::cout << "\n\nRunning foo: " << std::flush;
>>
>>         std::vector<GenericValue> noargs;
>>         GenericValue gv = EE->runFunction(FooF, noargs);
>>
>>         std::cout << "Result: " << gv.IntVal.toStringUnsigned(10) <<
>> "\n";
>>         return 0;
>> }
>>
>>
>>
>> 2008/8/19, Gordon Henriksen <gordonhenriksen at me.com>:
>> >
>> > On Aug 19, 2008, at 13:36, kirill havok wrote:
>> >
>> > I got very interested in LLVM project, and I decided to start writing
>> my own
>> > scripting language based on it. By studying the documentation, I
>> could not
>> > find how to call external function, written in C. That is, I have a
>> set of
>> > functions written in C/C++, I generate code, using LLVM C++ interface,
>> how
>> > can I call(or register in machine in run-time) my external functions?
>> Maybe
>> > I just missed something. Please, give in which direction to search.
>> >
>> > Hi Kirill,
>> >
>> > Since LLVM goes to the bare metal, there is no need for an "FFI" or
>> bindings
>> > to call native code. Simply create a declaration for the function-a
>> Function
>> > with no body-and call it as any other function in your program. (Also,
>> of
>> > course, link with a library to define the symbols.) It might be
>> instructive
>> > to examine the llvm-gcc -S -emit-llvm output of a program like this:
>> >
>> > int MyExternalFn(int, int, int);
>> >
>> > int main(int, const char**, const char**) {
>> >   return MyExternalFn(1, 2, 3);
>> > }
>> >
>> >
>> > Where you tweak MyExternalFn to have the desired prototype.
>> >
>> > To create a function declaration:
>> >
>> >
>> > From C++, simply call Function::Create and then do not add any basic
>> blocks.
>> > From LLVM assembly, use the keyword "declare" instead of "define":
>> > http://llvm.org/docs/LangRef.html#functionstructure
>> >
>> >
>> > If you're using the JIT, you'll need to do the above, but also may
>> need to
>> > register your functions using
>> > ExecutionEngine::addGlobalMapping.
>> >
>> > http://llvm.org/doxygen/classllvm_1_1ExecutionEngine.html#a8
>> >
>> >
>> > Note that the C calling convention do not map directly to LLVM IR for
>> many
>> > cases, so it's best to stick to simple parameter types (pointers and
>> ints,
>> > for example) and also to verify that the LLVM FunctionTypes you use
>> are
>> > correct on each platform you support.
>> >
>> > Good luck!
>> >
>> > - Gordon
>> >
>> >
>> > _______________________________________________
>> >  LLVM Developers mailing list
>> >  LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> >  http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >
>> >
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>