Adds support to macro expansion in setvar action

src/macro_expansion.h

@@ -19,6 +19,7 @@
 #include <vector>
 
 #include "modsecurity/modsecurity.h"
+#include "modsecurity/assay.h"
 
 #ifndef SRC_MACRO_EXPANSION_H_
 #define SRC_MACRO_EXPANSION_H_
@@ -29,6 +30,8 @@ namespace ModSecurity {
 class MacroExpansion {
  public:
     MacroExpansion();
+
+    static std::string expand(const std::string& input, Assay *assay);
 };