tdf#97966 Compiler plugin

Warns about redundant 'static' keywords in unnamed namespace.

Change-Id: Iecab69161e24d73e39a8dd5baaba6929e12d4f29
Reviewed-on: https://gerrit.libreoffice.org/23679
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

compilerplugins/clang/staticanonymous.cxx

@@ -0,0 +1,67 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ */
+#include "plugin.hxx"
+#include "compat.hxx"
+/*
+This is a compile check.
+
+Warns about functions with static keyword in an unnamed namespace.
+*/
+
+namespace loplugin
+{
+
+class StaticAnonymous
+    : public RecursiveASTVisitor< StaticAnonymous >
+    , public Plugin
+    {
+    public:
+        StaticAnonymous( const InstantiationData& data );
+        virtual void run() override;
+        bool VisitFunctionDecl( FunctionDecl* func );
+
+    };
+
+StaticAnonymous::StaticAnonymous( const InstantiationData& data )
+    : Plugin( data )
+    {
+    }
+
+void StaticAnonymous::run()
+    {
+    TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
+    }
+
+
+bool StaticAnonymous::VisitFunctionDecl( FunctionDecl* func )
+
+    {
+    if( ignoreLocation( func ) )
+        return true;
+    if( func -> isInAnonymousNamespace () )
+    {
+      if ( !isa<CXXMethodDecl>(func) && !compat::isInExternCContext(*func) )
+         {
+            if(func-> getStorageClass() == SC_Static)
+               {
+                    report( DiagnosticsEngine::Warning,
+                        "redundant 'static' keyword in unnamed namespace",
+                        func->getLocStart());
+               }
+         }
+    }
+
+    return true;
+    }
+
+// Register the plugin action with the LO plugin handling.
+static Plugin::Registration< StaticAnonymous > X( "staticanonymous",true);
+
+} // namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */