Linking several LLVM C++ modules together segfaults in lli - c++

Question

I'm trying a very simple example with LLVM/clang and seem to fail.
I try the following:
clang++ -emit-llvm -c -x c++ -o main.bc -isystem include/ main.cc
clang++ -emit-llvm -c -x c++ -o test_class.bc -isystem include/ test_class.cc
llvm-link main.bc test_class.bc -o all.bc
lli all.bc
However, 4. fails (segfaults) with:
0 libLLVM-3.3.so 0x0000003b890f9e52 llvm::sys::PrintStackTrace(_IO_FILE*) + 34
1 libLLVM-3.3.so 0x0000003b890f9cb9
2 libpthread.so.0 0x0000003b8520efa0
3 libLLVM-3.3.so 0x0000003b89982790 llvm::MachineJumpTableInfo::getEntrySize(llvm::DataLayout const&) const + 0
4 libLLVM-3.3.so 0x0000003b894bfb23
5 libLLVM-3.3.so 0x0000003b894c8dc3
6 libLLVM-3.3.so 0x0000003b8981b27f
7 libLLVM-3.3.so 0x0000003b8969d2d6 llvm::FPPassManager::runOnFunction(llvm::Function&) + 422
8 libLLVM-3.3.so 0x0000003b8969d3f6 llvm::FunctionPassManagerImpl::run(llvm::Function&) + 102
9 libLLVM-3.3.so 0x0000003b8969d4cb llvm::FunctionPassManager::run(llvm::Function&) + 91
10 libLLVM-3.3.so 0x0000003b894b3264 llvm::JIT::jitTheFunction(llvm::Function*, llvm::MutexGuard const&) + 36
11 libLLVM-3.3.so 0x0000003b894b394f llvm::JIT::runJITOnFunctionUnlocked(llvm::Function*, llvm::MutexGuard const&) + 15
12 libLLVM-3.3.so 0x0000003b894b3b7e llvm::JIT::getPointerToFunction(llvm::Function*) + 254
13 libLLVM-3.3.so 0x0000003b894c6649
14 libLLVM-3.3.so 0x0000003b894c909c
15 libLLVM-3.3.so 0x0000003b8981b27f
16 libLLVM-3.3.so 0x0000003b8969d2d6 llvm::FPPassManager::runOnFunction(llvm::Function&) + 422
17 libLLVM-3.3.so 0x0000003b8969d3f6 llvm::FunctionPassManagerImpl::run(llvm::Function&) + 102
18 libLLVM-3.3.so 0x0000003b8969d4cb llvm::FunctionPassManager::run(llvm::Function&) + 91
19 libLLVM-3.3.so 0x0000003b894b3264 llvm::JIT::jitTheFunction(llvm::Function*, llvm::MutexGuard const&) + 36
20 libLLVM-3.3.so 0x0000003b894b394f llvm::JIT::runJITOnFunctionUnlocked(llvm::Function*, llvm::MutexGuard const&) + 15
21 libLLVM-3.3.so 0x0000003b894b3b7e llvm::JIT::getPointerToFunction(llvm::Function*) + 254
22 lli 0x00000000004073cf main + 2527
23 libc.so.6 0x0000003b84621b75 __libc_start_main + 245
24 lli 0x000000000040a271
Stack dump:
0. Program arguments: lli all.bc
1. Running pass 'X86 Machine Code Emitter' on function '#main'
2. Running pass 'X86 Machine Code Emitter' on function '#_ZN10test_classC2ESs'
[1] 15327 segmentation fault (core dumped) lli all.bc
Do I have a fundamental missunderstanding on how this is supposed to work? My ultimate goal is to do the compilation
part using the libclang API, but for now understanding what I do wrong here would be awesome! Thanks!
I attached the source code for the example below:
include/test_class.h:
#ifndef __TEST_CLASS_H__
#define __TEST_CLASS_H__
#include <string>
#include <iostream>
struct test_class
{
test_class(std::string foo);
~test_class();
std::string foo;
};
#endif
test_class.cc:
#include <test_class.h>
test_class::test_class(std::string foo) : foo(foo)
{
std::cout << foo << std::endl;
}
test_class::~test_class(void)
{
}
main.cc:
#include <cstdlib>
#include <string>
#include <iostream>
#include <test_class.h>
int main(int argc, char** argv)
{
test_class test("foo");
return EXIT_SUCCESS;
}

Answer 1

In test_class you refer to std::string. I guess, calls to related functions are marked external if you have a look into the IR (eg: llvm-dis < all.bc).
If you compile to "normal" executable code, these calls are resolved by the linker.
Since you link manually with llvm-link you will have to provide IR-code for the C++ libraries, otherwise execution might fail.