[cfe-dev] Call external (non-JIT) function from JIT
fk.fuchs at googlemail.com
Tue Jul 13 12:46:48 PDT 2010
Hi I'm rather new to llvm+clang,
but i'm intrigued by the idea to create some jit "scripting" extension for arbitrary c++ applications
using llvm and clang (the scripts shall use c or even c++ syntax).
I started looking into the clang-interpreter example which in my eyes is already half way there.
Now I tried to extend the functionality of the example by adding a mapping for an already defined
C-function to the JIT. ... Strangely enough the code did compile afterwards, but of course it didn't work.
Here is what I did:
int Execute(llvm::Module *Mod, char * const *envp)
llvm::Function *EntryFn = Mod->getFunction("main");
// external function
llvm::Function *KnownFunction = llvm::Function::Create(llvm::TypeBuilder<int(int), false>::get(Mod->getContext()),llvm::GlobalValue::ExternalLinkage, "known", Mod);
printf("Ext. CALL %d \n\n",i);
tests> clang-interpreter -v my_test.cpp
Here's the error message:
main.cpp:5:4: error: use of undeclared identifier 'known'
1 error generated.
also defining "known" as: extern "C" int known(int); does not solve the issue, the error is then:
LLVM ERROR: Program used external function 'known' which could not be resolved!
Obviously something else needs to be done in order to resolve the function., but I don't know what.
So any help is appreciated!
Thank you in advance
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