Clean up UNUSED() macro

    1. Use [[maybe_unused]] C++17 attribute instead of GCC/Clang __attribute__((unused))

       The attribute should appear immediately AFTER the name of the parameter,
       before any array dimensions (this should fix ARM build issue where old-style
       __attribute__((unused)) worked after an array dimension but [[maybe_unused]]
       did not work).

       The UNUSED() macro is almost always called with only the name of the function
       parameter, without any type information, so the [[maybe_unused]] attribute
       cannot be placed BEFORE the macro argument, where it would be ignored as not
       applying to the immediately preceding type. For it to appear BEFORE the
       parameter name, it would need to appear before the type as well, and then all
       of the calls to UNUSED() would need to be modified to look something like:

       UNUSED(const std::string& name)

       instead of:

       const std::string& UNUSED(name)

       Although cppreference.com is scant on details, my research has found that
       attributes applying to specific identifiers must appear immediately AFTER
       the name. The old __attribute__((unused)) GCC/Clang attribute appeared
       after the name, and so does [[maybe_unused]] with this change.

    2. Remove UNUSED() macro used in function declarations which are not
       definitions, since the compiler does not check whether function parameters
       are actually used in declarations, only in definitions.

    3. Remove UNUSED() macro that is used where the parameter is not unused
       anymore.

Author: leekillough

src/sst/core/eli/categoryInfo.h

@@ -42,7 +42,7 @@ class ProvidesCategory
         }
     }
 
-    void toString(std::ostream& UNUSED(os)) const { os << "      Category: " << categoryName(cat_) << "\n"; }
+    void toString(std::ostream& os) const { os << "      Category: " << categoryName(cat_) << "\n"; }
 
     template <class XMLNode>
     void outputXML(XMLNode* UNUSED(node))

src/sst/core/impl/interactive/simpleDebug.h

@@ -63,8 +63,8 @@ class SimpleDebugger : public SST::InteractiveConsole
 
     std::vector<std::string> tokenize(std::vector<std::string>& tokens, const std::string& input);
 
-    void cmd_pwd(std::vector<std::string>& UNUSED(tokens));
-    void cmd_ls(std::vector<std::string>& UNUSED(tokens));
+    void cmd_pwd(std::vector<std::string>& tokens);
+    void cmd_ls(std::vector<std::string>& tokens);
     void cmd_cd(std::vector<std::string>& tokens);
     void cmd_print(std::vector<std::string>& tokens);
     void cmd_set(std::vector<std::string>& tokens);

src/sst/core/interfaces/stdMem.h

@@ -931,7 +931,7 @@ class StandardMem : public SubComponent
         virtual std::string getString()      = 0; /* String representation for debug/output/etc. */
 
         /* This needs to be serializable so that we can use it in events in parallel simulations */
-        virtual void serialize_order(SST::Core::Serialization::serializer& UNUSED(ser)) override = 0;
+        virtual void serialize_order(SST::Core::Serialization::serializer& ser) override = 0;
         // ImplementSerializable(SST::Interfaces::StandardMem::CustomData);
         ImplementVirtualSerializable(CustomData);
     };

src/sst/core/profile/eventHandlerProfileTool.h

@@ -95,7 +95,7 @@ class EventHandlerProfileToolCount : public EventHandlerProfileTool
     uintptr_t registerLinkAttachTool(const AttachPointMetaData& mdata) override;
 
     void beforeHandler(uintptr_t key, const SST::Event* event) override;
-    void eventSent(uintptr_t UNUSED(key), Event*& UNUSED(ev)) override;
+    void eventSent(uintptr_t key, Event*& ev) override;
 
     void outputData(FILE* fp) override;
 

src/sst/core/shared/sharedObject.h

@@ -54,7 +54,7 @@ class SharedObjectChangeSet : public SST::Core::Serialization::serializable
        @param manager The SharedObjectDataManager for the rank.  This
        is used to get the named shared data.
      */
-    virtual void applyChanges(SharedObjectDataManager* UNUSED(manager)) = 0;
+    virtual void applyChanges(SharedObjectDataManager* manager) = 0;
 
     /**
        Clears the data.  Used after transfering data to other ranks to

src/sst/core/sstinfo.h

@@ -124,13 +124,13 @@ class SSTInfoConfig : public ConfigShared
         return 0;
     }
 
-    int setXMLOutput(const std::string& UNUSED(arg))
+    int setXMLOutput(const std::string& arg)
     {
         m_XMLFilePath = arg;
         return 0;
     }
 
-    int setLibs(const std::string& UNUSED(arg))
+    int setLibs(const std::string& arg)
     {
         addFilter(arg);
         return 0;

src/sst/core/warnmacros.h

@@ -14,7 +14,7 @@
 #ifndef SST_CORE_WARNMACROS_H
 #define SST_CORE_WARNMACROS_H
 
-#define UNUSED(x) x __attribute__((unused))
+#define UNUSED(x) x [[maybe_unused]]
 
 #define DIAG_STR(s)              #s
 #define DIAG_JOINSTR(x, y)       DIAG_STR(x##y)