Fix macroexpansion to make it behave like the official compiler

See flow-storm/flow-storm-debugger#210

Author: jpmonettas

pom.xml

@@ -5,7 +5,7 @@
   <artifactId>clojure</artifactId>
   <name>clojure</name>
   <packaging>jar</packaging>
-  <version>1.12.3-1</version>
+  <version>1.12.3-4</version>
   <url>http://clojure.org/</url>
   <description>Clojure core environment and runtime library.</description>
 

src/jvm/clojure/lang/Compiler.java

@@ -7812,7 +7812,7 @@ public static void checkSpecs(Var v, ISeq form) {
 }
 
 public static Object macroexpand1(Object x) {
-	IPersistentMap xMeta = RT.meta(x);
+	IPersistentMap stormMeta = Utils.stormMeta(RT.meta(x));
 
 	if(x instanceof ISeq)
 		{
@@ -7829,7 +7829,7 @@ public static Object macroexpand1(Object x) {
 				try
 					{
                     ISeq args = RT.cons(form, RT.cons(Compiler.LOCAL_ENV.get(), form.next()));
-					return  Utils.mergeMeta(v.applyTo(args), xMeta);
+					return  Utils.mergeMeta(v.applyTo(args), stormMeta);
 					}
 				catch(ArityException e)
 					{
@@ -7877,7 +7877,7 @@ public static Object macroexpand1(Object x) {
 						{
 						target = ((IObj)RT.list(IDENTITY, target)).withMeta(RT.map(RT.TAG_KEY,CLASS));
 						}
-					return Utils.mergeMeta(preserveTagAndCoord(form, RT.listStar(DOT, target, meth, form.next().next())), xMeta);
+					return Utils.mergeMeta(preserveTagAndCoord(form, RT.listStar(DOT, target, meth, form.next().next())), stormMeta);
 					}
 				else
 					{
@@ -7893,7 +7893,7 @@ public static Object macroexpand1(Object x) {
 					//(StringBuilder. "foo") => (new StringBuilder "foo")	
 					//else 
 					if(idx == sname.length() - 1)
-						return Utils.mergeMeta(RT.listStar(NEW, Symbol.intern(sname.substring(0, idx)), form.next()), xMeta);
+						return Utils.mergeMeta(RT.listStar(NEW, Symbol.intern(sname.substring(0, idx)), form.next()), stormMeta);
 					}
 				}
 			}

src/jvm/clojure/storm/Utils.java

@@ -36,8 +36,6 @@
 
 public class Utils {
 
-    private static final Keyword TAG_KEY = Keyword.intern(null, "tag");
-	
 	public static Object mergeMeta(Object x, IPersistentMap m) {
 		if (x instanceof clojure.lang.IObj && RT.count(m) > 0) {
             // if x supports meta and there is meta to merge
@@ -56,9 +54,7 @@ public static Object mergeMeta(Object x, IPersistentMap m) {
             // m meta overrides the input Object meta when both have
             for (Object meo : m) {
                 IMapEntry me = (IMapEntry) meo;
-                if (!TAG_KEY.equals(me.key())) {
-                    retMeta = retMeta.assoc(me.key(), me.val());
-                }
+                retMeta = retMeta.assoc(me.key(), me.val());                
             }
 
             return o.withMeta(retMeta);
@@ -67,6 +63,26 @@ public static Object mergeMeta(Object x, IPersistentMap m) {
         }
     }
 
+    public static IPersistentMap stormMeta(IPersistentMap m) {
+        if (m != null && RT.count(m) > 0) {
+            IPersistentMap retMeta = PersistentHashMap.EMPTY;
+
+            for (Object meObj : m) {
+                IMapEntry me = (IMapEntry) meObj;
+                if (me.key().equals(LispReader.COORD_KEY) ||
+                    me.key().equals(Compiler.STORM_COORDS_EMITTED_COORDS_KEY) ||
+                    me.key().equals(Compiler.SKIP_TRACE_KEY) ||
+                    me.key().equals(Compiler.FN_TRACE_SYM_KEY)) {
+                    retMeta = retMeta.assoc(me.key(), me.val());
+                    }
+                }
+            return retMeta;
+        } else {
+            return m;
+        }
+    }
+    
+    
 	public static Symbol maybeGetTraceSymbol(Symbol sym, ISeq form){
         // If the form is the expansion of a defmethod we use the symbol of
         // the defmethod as a trace symbol.