new constantfunction loplugin

Change-Id: Ie9b7a0c41fc4dbd2560ceff6bae9ab85357f518b

compilerplugins/clang/compat.hxx

@@ -23,6 +23,7 @@
 #include "clang/Basic/Linkage.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Visibility.h"
+#include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/StringRef.h"
@@ -210,6 +211,17 @@ inline void addPPCallbacks(
 #endif
 }
 
+inline bool isMacroBodyExpansion(clang::CompilerInstance& compiler, clang::SourceLocation location)
+{
+#if (__clang_major__ == 3 && __clang_minor__ >= 3) || __clang_major__ > 3
+    return compiler.getSourceManager().isMacroBodyExpansion(location);
+#else
+    return location.isMacroID()
+        && !compiler.getSourceManager().isMacroArgExpansion(location);
+#endif
+}
+
+
 }
 
 #endif