Errors while compiling C++ file including LLVM API headers - c++

Question

Hello,
I have installed llvm and llvm-debuginfo using apt install and am trying to compile this file:
llvm_test.cpp
#include <stdio.h>
#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/IR/Module.h"
int main( int argc, char* argv[] )
{
if( argc < 2 )
llvm::errs() << "Expected an argument - IR file name\n";
llvm::LLVMContext &context = llvm::getGlobalContext();
llvm::SMDiagnostic err;
llvm::Module* module = llvm::ParseIRFile( argv[1], err, context );
if( !mod )
{
err.print( argv[0], errs() );
return 1;
}
return 0;
}
Using following command:
$ clang++ -std=c++11 llvm_test.cpp `llvm-config --system-libs --cppflags --ldflags --libs core` -o llvm_test
But it doesn't seem to find required API headers. This is the error message:
llvm_test.cpp:9:13: error: no member named 'errs' in namespace 'llvm'
llvm::errs() << "Expected an argument - IR file name\n";
~~~~~~^
llvm_test.cpp:11:39: error: no member named 'getGlobalContext' in namespace
'llvm'
llvm::LLVMContext &context = llvm::getGlobalContext();
~~~~~~^
llvm_test.cpp:13:33: error: no member named 'ParseIRFile' in namespace 'llvm'
llvm::Module* module = llvm::ParseIRFile( argv[1], err, context );
~~~~~~^
llvm_test.cpp:15:9: error: use of undeclared identifier 'mod'
if( !mod )
^
llvm_test.cpp:17:27: error: use of undeclared identifier 'errs'
err.print( argv[0], errs() );
^
5 errors generated.
Adding "support" to llvm-config arguments, as suggested in comments, doesn't change anything: same errors.
What is wrong with this?
Note: I am using Cygwin on Windows and I meant apt-cyg (apt like tool for Cygwin) under apt.

Answer 1

1) error: no member named 'errs' in namespace 'llvm'
You must include: #include "llvm/Support/raw_ostream.h"
2) error: no member named 'getGlobalContext' in namespace
It is due to getGlobalContext was removed after llvm 3.6. So use: LLVMContext context; and give a reference of it where required.
3) error: no member named 'ParseIRFile' in namespace 'llvm'
You must include: #include "llvm/IRReader/IRReader.h"
4)error: use of undeclared identifier 'mod'
Use module instead of mod in here

Answer 2

If you need errs, you should include the right header:
#include "llvm/Support/raw_ostream.h"
ParseIRFile should be in llvm/IRReader/IRReader.h
#include "llvm/IRReader/IRReader.h"