In this example, we will take the opportunity to introduce you to the Clang C++ interface and will not rely on the libclang C interface anymore. We will create a program that will apply the lexer, the parser, and the semantic analysis to input files by using the internal Clang C++ classes; thus, we will have the opportunity to do the work of a simple FrontendAction object. You can continue using the Makefile that we presented at the beginning of this chapter. However, you may be interested in turning off the -Wall -Wextra compiler flags because it will generate a large volume of warnings for Clang headers regarding unused parameters.

The source code for this example is reproduced as follows:

#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Host.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/FileManager...