tutorial examples for writing new Clang plugin actions

http://wiki.documentfoundation.org/Clang_plugins

Change-Id: Ieb4fc186490e81ab961c094ca0a7fcdabc0f348f

compilerplugins/clang/store/tutorial/tutorial3.hxx

@@ -0,0 +1,39 @@
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+#ifndef TUTORIAL3_H
+#define TUTORIAL3_H
+
+#include "plugin.hxx"
+
+namespace loplugin
+{
+
+// Similar like for Tutorial2, but this time the base class is RewritePlugin.
+class Tutorial3
+    : public RecursiveASTVisitor< Tutorial3 >
+    , public RewritePlugin
+    {
+    public:
+        // One more argument for ctor.
+        Tutorial3( ASTContext& context, Rewriter& rewriter );
+        virtual void run();
+        // Will be called for every if statement.
+        bool VisitIfStmt( IfStmt* ifstmt );
+    private:
+        // Helper function to check if the statement is 'return false;' and
+        // modify it if yes.
+        void modifyReturnFalse( const Stmt* stmt );
+    };
+
+} // namespace
+
+#endif // POSTFIXINCREMENTFIX_H
+