Merge pull request #4735 from soc/SI-9437

SI-9437 Emit and support parameter names in class files

3 files changed, 32 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index 1ec9ba8a95..1b5ece772c 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -841,6 +841,17 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
       }
     }
 
+    /*
+     * must-single-thread
+     */
+    def emitParamNames(jmethod: asm.MethodVisitor, params: List[Symbol]) = {
+      for (param <- params) {
+        var access = asm.Opcodes.ACC_FINAL
+        if (param.isArtifact)
+          access |= asm.Opcodes.ACC_SYNTHETIC
+        jmethod.visitParameter(param.name.decoded, access)
+      }
+    }
   } // end of trait BCAnnotGen
 
   trait BCJGenSigGen {
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
index 7180c25d25..9dea21154f 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
@@ -512,7 +512,7 @@ abstract class BCodeSkelBuilder extends BCodeHelpers {
     /*
      * must-single-thread
      */
-    def initJMethod(flags: Int, paramAnnotations: List[List[AnnotationInfo]]) {
+    def initJMethod(flags: Int, params: List[Symbol]) {
 
       val jgensig = getGenericSignature(methSymbol, claszSymbol)
       addRemoteExceptionAnnot(isCZRemote, hasPublicBitSet(flags), methSymbol)
@@ -532,10 +532,9 @@ abstract class BCodeSkelBuilder extends BCodeHelpers {
         mkArray(thrownExceptions)
       ).asInstanceOf[asm.tree.MethodNode]
 
-      // TODO param names: (m.params map (p => javaName(p.sym)))
-
+      emitParamNames(mnode, params)
       emitAnnotations(mnode, others)
-      emitParamAnnotations(mnode, paramAnnotations)
+      emitParamAnnotations(mnode, params.map(_.annotations))
 
     } // end of method initJMethod
 
@@ -574,8 +573,7 @@ abstract class BCodeSkelBuilder extends BCodeHelpers {
         if (isNative)                asm.Opcodes.ACC_NATIVE     else 0  // native methods of objects are generated in mirror classes
       )
 
-      // TODO needed? for(ann <- m.symbol.annotations) { ann.symbol.initialize }
-      initJMethod(flags, params.map(p => p.symbol.annotations))
+      initJMethod(flags, params.map(_.symbol))
 
       /* Add method-local vars for LabelDef-params.
        *
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index 406411f21f..fffd48d145 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -816,6 +816,23 @@ abstract class ClassfileParser {
           val c1 = convertTo(c, symtype)
           if (c1 ne null) sym.setInfo(ConstantType(c1))
           else devWarning(s"failure to convert $c to $symtype")
+        case tpnme.MethodParametersATTR =>
+          def readParamNames(): Unit = {
+            import tools.asm.Opcodes.ACC_SYNTHETIC
+            val paramCount = u1
+            var i = 0
+            while (i < paramCount) {
+              val name = pool.getName(u2)
+              val access = u2
+              if ((access & ACC_SYNTHETIC) != ACC_SYNTHETIC) { // name not synthetic
+                val params = sym.paramss.head // Java only has exactly one parameter list
+                params(i).name = name.encode
+                params(i).resetFlag(SYNTHETIC)
+              }
+              i += 1
+            }
+          }
+          readParamNames()
         case tpnme.ScalaSignatureATTR =>
           if (!isScalaAnnot) {
             devWarning(s"symbol ${sym.fullName} has pickled signature in attribute")