setup: Added clang and llvm

Adds clang and llvm include directories and libraries to the build. The
environment variable CLANG_DIR is used to define the location of llvm
and clang. A simple clang tool implementation was added to assure proper
operation of the libraries.

src/lib/data/parser/clang.cpp

@@ -0,0 +1,58 @@
+#include "clang.h"
+
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/Tooling/Tooling.h"
+
+using namespace clang;
+
+class FindNamedClassVisitor
+  : public RecursiveASTVisitor<FindNamedClassVisitor> {
+public:
+  explicit FindNamedClassVisitor(ASTContext *Context)
+    : Context(Context) {}
+
+  bool VisitCXXRecordDecl(CXXRecordDecl *Declaration) {
+    if (Declaration->getQualifiedNameAsString() == "n::m::C") {
+      FullSourceLoc FullLocation = Context->getFullLoc(Declaration->getLocStart());
+      if (FullLocation.isValid())
+        llvm::outs() << "Found declaration at "
+                     << FullLocation.getSpellingLineNumber() << ":"
+                     << FullLocation.getSpellingColumnNumber() << "\n";
+    }
+    return true;
+  }
+
+private:
+  ASTContext *Context;
+};
+
+class FindNamedClassConsumer : public clang::ASTConsumer {
+public:
+  explicit FindNamedClassConsumer(ASTContext *Context)
+    : Visitor(Context) {}
+
+  virtual void HandleTranslationUnit(clang::ASTContext &Context) {
+    Visitor.TraverseDecl(Context.getTranslationUnitDecl());
+  }
+private:
+  FindNamedClassVisitor Visitor;
+};
+
+class FindNamedClassAction : public clang::ASTFrontendAction {
+public:
+  virtual clang::ASTConsumer *CreateASTConsumer(
+    clang::CompilerInstance &Compiler, llvm::StringRef InFile) {
+    return new FindNamedClassConsumer(&Compiler.getASTContext());
+  }
+};
+
+int clang_main(int argc, char **argv) {
+  if (argc > 1) {
+    clang::tooling::runToolOnCode(new FindNamedClassAction, argv[1]);
+  }
+  return 0;
+}

src/lib/data/parser/clang.h

@@ -0,0 +1,6 @@
+#ifndef CLANG_MAIN_H
+#define CLANG_MAIN_H
+
+int clang_main(int argc, char **argv);
+
+#endif // CLANG_MAIN_H