Expanded bytecode testing code.

def sameMethodAndFieldSignatures compares two classes to verify
they have all the same methods and fields, and no others.

Author: paulp

src/partest/scala/tools/partest/AsmNode.scala

@@ -0,0 +1,60 @@
+package scala.tools.partest
+
+import scala.collection.JavaConverters._
+import scala.tools.asm
+import asm._
+import asm.tree._
+import java.lang.reflect.Modifier
+
+sealed trait AsmNode[+T] {
+  def node: T
+  def access: Int
+  def desc: String
+  def name: String
+  def signature: String
+  def attrs: List[Attribute]
+  def visibleAnnotations: List[AnnotationNode]
+  def invisibleAnnotations: List[AnnotationNode]
+  def characteristics = f"$name%15s $desc%-30s$accessString$sigString"
+
+  private def accessString = if (access == 0) "" else " " + Modifier.toString(access)
+  private def sigString = if (signature == null) "" else " " + signature
+  override def toString = characteristics
+}
+
+object AsmNode {
+  type AsmMethod = AsmNode[MethodNode]
+  type AsmField = AsmNode[FieldNode]
+  type AsmMember = AsmNode[_]
+
+  implicit class ClassNodeOps(val node: ClassNode) {
+    def fieldsAndMethods: List[AsmMember] = {
+      val xs: List[AsmMember] = (
+           node.methods.asScala.toList.map(x => (x: AsmMethod))
+        ++ node.fields.asScala.toList.map(x => (x: AsmField))
+      )
+      xs sortBy (_.characteristics)
+    }
+  }
+  implicit class AsmMethodNode(val node: MethodNode) extends AsmNode[MethodNode] {
+    def access: Int                                = node.access
+    def desc: String                               = node.desc
+    def name: String                               = node.name
+    def signature: String                          = node.signature
+    def attrs: List[Attribute]                     = node.attrs.asScala.toList
+    def visibleAnnotations: List[AnnotationNode]   = node.visibleAnnotations.asScala.toList
+    def invisibleAnnotations: List[AnnotationNode] = node.invisibleAnnotations.asScala.toList
+  }
+  implicit class AsmFieldNode(val node: FieldNode) extends AsmNode[FieldNode] {
+    def access: Int                                = node.access
+    def desc: String                               = node.desc
+    def name: String                               = node.name
+    def signature: String                          = node.signature
+    def attrs: List[Attribute]                     = node.attrs.asScala.toList
+    def visibleAnnotations: List[AnnotationNode]   = node.visibleAnnotations.asScala.toList
+    def invisibleAnnotations: List[AnnotationNode] = node.invisibleAnnotations.asScala.toList
+  }
+
+  def apply(node: MethodNode): AsmMethodNode = new AsmMethodNode(node)
+  def apply(node: FieldNode): AsmFieldNode   = new AsmFieldNode(node)
+}

src/partest/scala/tools/partest/BytecodeTest.scala

@@ -3,9 +3,10 @@ package scala.tools.partest
 import scala.tools.nsc.util.JavaClassPath
 import scala.collection.JavaConverters._
 import scala.tools.asm
-import asm.ClassReader
+import asm.{ ClassReader }
 import asm.tree.{ClassNode, MethodNode, InsnList}
 import java.io.InputStream
+import AsmNode._
 
 /**
  * Provides utilities for inspecting bytecode using ASM library.
@@ -29,21 +30,47 @@ import java.io.InputStream
  *
  */
 abstract class BytecodeTest extends ASMConverters {
+  import instructions._
 
   /** produce the output to be compared against a checkfile */
   protected def show(): Unit
 
   def main(args: Array[String]): Unit = show
 
-// asserts
+  // asserts
   def sameBytecode(methA: MethodNode, methB: MethodNode) = {
     val isa = instructions.fromMethod(methA)
     val isb = instructions.fromMethod(methB)
     if (isa == isb) println("bytecode identical")
     else diffInstructions(isa, isb)
   }
 
-  import instructions._
+  // Do these classes have all the same methods, with the same names, access,
+  // descriptors and generic signatures? Method bodies are not considered, and
+  // the names of the classes containing the methods are substituted so they do
+  // not appear as differences.
+  def sameMethodAndFieldSignatures(clazzA: ClassNode, clazzB: ClassNode): Boolean = {
+    val ms1 = clazzA.fieldsAndMethods.toIndexedSeq
+    val ms2 = clazzB.fieldsAndMethods.toIndexedSeq
+    val name1 = clazzA.name
+    val name2 = clazzB.name
+
+    if (ms1.length != ms2.length) {
+      println("Different member counts in $name1 and $name2")
+      false
+    }
+    else (ms1, ms2).zipped forall { (m1, m2) =>
+      val c1 = m1.characteristics
+      val c2 = m2.characteristics.replaceAllLiterally(name2, name1)
+      if (c1 == c2)
+        println(s"[ok] $m1")
+      else
+        println(s"[fail]\n  in $name1: $c1\n  in $name2: $c2")
+
+      c1 == c2
+    }
+  }
+
   // bytecode is equal modulo local variable numbering
   def equalsModuloVar(a: Instruction, b: Instruction) = (a, b) match {
     case _ if a == b => true