LLVM: linking errors in VS 2015 - c++

Question

I have downloaded source and built LLVM using CMake and VS 2015.
My sample program is the following:
#include <iostream>
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/CFG.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
int main(int argc, char **argv) {
if (argc < 2) {
errs() << "Usage: " << argv[0] << " <IR file>\n";
return 1;
}
// Parse the input LLVM IR file into a module.
SMDiagnostic Err;
LLVMContext TheContext;
std::unique_ptr<Module> Mod = parseIRFile(argv[1], Err, TheContext);
if (!Mod) {
Err.print(argv[0], errs());
return 1;
}
// ... use module
}
I get the following linking errors after having included the LLVM lib directory in the linker library path:
Severity Code Description Project File Line Suppression State
Error LNK2019 unresolved external symbol "public: __thiscall llvm::LLVMContext::LLVMContext(void)" (??0LLVMContext#llvm##QAE#XZ) referenced in function _main LLVM_IRReader c:\Users\nlykkei\documents\visual studio 2015\Projects\LLVM_IRReader\LLVM_IRReader\Main.obj 1
Severity Code Description Project File Line Suppression State
Error LNK2019 unresolved external symbol "public: __thiscall llvm::Module::~Module(void)" (??1Module#llvm##QAE#XZ) referenced in function "public: void * __thiscall llvm::Module::`scalar deleting destructor'(unsigned int)" (??_GModule#llvm##QAEPAXI#Z) LLVM_IRReader c:\Users\nlykkei\documents\visual studio 2015\Projects\LLVM_IRReader\LLVM_IRReader\Main.obj 1
Severity Code Description Project File Line Suppression State
Error LNK2019 unresolved external symbol "class llvm::raw_ostream & __cdecl llvm::errs(void)" (?errs#llvm##YAAAVraw_ostream#1#XZ) referenced in function _main LLVM_IRReader c:\Users\nlykkei\documents\visual studio 2015\Projects\LLVM_IRReader\LLVM_IRReader\Main.obj 1
Severity Code Description Project File Line Suppression State
Error LNK2019 unresolved external symbol "public: void __thiscall llvm::SMDiagnostic::print(char const *,class llvm::raw_ostream &,bool,bool)const " (?print#SMDiagnostic#llvm##QBEXPBDAAVraw_ostream#2#_N2#Z) referenced in function _main LLVM_IRReader c:\Users\nlykkei\documents\visual studio 2015\Projects\LLVM_IRReader\LLVM_IRReader\Main.obj 1
Does anyone know how to resolve these errors? I see, e.g., raw_ostream.obj in the LLVM build directory...

Answer 1

I've never used LLVM but based on your error messages, the linker didn't succeed in finding the LLVM class implementations.
To my point of view, including the LLVM lib directory is not enough. You have to include also the LLVM libraries (.lib which implement the LLVM classes) you want to link with.