CLJ-1645: protocol class has no source file information

Signed-off-by: Stuart Halloway <stu@cognitect.com>

Author: louyx

src/clj/clojure/genclass.clj

@@ -669,6 +669,7 @@
        iname nil "java/lang/Object"
        (when (seq extends)
          (into-array (map #(.getInternalName (asm-type %)) extends))))
+    (when (not= "NO_SOURCE_FILE" *source-path*) (. cv visitSource *source-path* nil))
     (add-annotations cv (meta name))
     (doseq [[mname pclasses rclass pmetas] methods]
       (let [mv (. cv visitMethod (+ Opcodes/ACC_PUBLIC Opcodes/ACC_ABSTRACT)

test/clojure/test_clojure/genclass.clj

@@ -141,3 +141,11 @@
                "returnsFloatArray"   :floats
                "returnsDoubleArray"  :doubles
                "returnsBooleanArray" :booleans))))))
+
+(deftest gen-interface-source-file
+  (let [classReader (clojure.asm.ClassReader. "clojure.test_clojure.genclass.examples.ArrayGenInterface")
+        sourceFile (StringBuilder.)
+        sourceVisitor (proxy [clojure.asm.ClassVisitor] [clojure.asm.Opcodes/ASM4 nil]
+                        (visitSource [source debug] (.append sourceFile source)))]
+    (.accept classReader sourceVisitor 0)
+    (is (= "examples.clj" (str sourceFile)))))