From 4ccfc7ec63a8986140fbd9c9d21852e2ad509e57 Mon Sep 17 00:00:00 2001
From: Philippe Suter <philippe.suter@gmail.com>
Date: Sun, 2 Dec 2012 23:32:42 +0100
Subject: [PATCH] First steps with dynamic loading.

We can now (sort of) load cafebabe-generated classes in memory. The API
is not final.
---
 src/main/scala/Test.scala                     | 59 -------------------
 src/main/scala/cafebabe/ClassFile.scala       |  3 -
 src/main/scala/cafebabe/Defaults.scala        |  2 +-
 .../scala/cafebabe/test/DynamicLoading.scala  | 25 ++++++++
 4 files changed, 26 insertions(+), 63 deletions(-)
 delete mode 100644 src/main/scala/Test.scala
 create mode 100644 src/test/scala/cafebabe/test/DynamicLoading.scala

diff --git a/src/main/scala/Test.scala b/src/main/scala/Test.scala
deleted file mode 100644
index 71de26d..0000000
--- a/src/main/scala/Test.scala
+++ /dev/null
@@ -1,59 +0,0 @@
-object Test {
-  def main(args : Array[String]) : Unit = {
-    import cafebabe.AbstractByteCodes._
-    import cafebabe.ByteCodes._
-
-    val cf = new cafebabe.ClassFile("Test", None)
-
-    cf.addField("Ljava/lang/String;", "name")
-
-    cf.addDefaultConstructor
-
-    {
-      val ch = cf.addMethod("I", "sayHello", "I", "Z", "Ljava/lang/String;").codeHandler
-      ch << Ldc(41)
-      ch << DefaultNew("Oh") << Ldc(3.14) << InvokeVirtual("Oh", "getInt", "(D)I") << IADD
-      ch << IRETURN
-      ch.freeze
-    }
-
-    {
-      val ch = cf.addMethod("I", "jumpOver").codeHandler
-      ch << Ldc(42)
-      val fresh: Int = ch.getFreshVar
-      ch << Goto("after")
-      ch << POP << Ldc(41)
-      ch << Label("after")
-      ch << IRETURN
-      ch.freeze
-    }
-
-    {
-      val ch = cf.addMethod("I", "fact", "I").codeHandler
-      val label = ch.getFreshLabel("else")
-      ch << ILoad(1) << Ldc(1) << If_ICmpGt(label) << Ldc(1) <<
-               IRETURN << Label(label) << ILoad(1) << ALoad(0) <<
-               ILoad(1) << Ldc(1) << ISUB << InvokeVirtual("Test", "fact", "(I)I") <<
-               IMUL << IRETURN
-
-      ch.freeze
-    }
-
-    cf.writeToFile("./classfiles/Test.class")
-
-    val classFile = new cafebabe.ClassFile("HWGenerated", None)
-    classFile.addDefaultConstructor
-    val codeHandler = classFile.addMainMethod.codeHandler
-
-    codeHandler <<
-      GetStatic("java/lang/System", "out", "Ljava/io/PrintStream;") <<
-      Ldc("Hello world!") <<
-      InvokeVirtual("java/io/PrintStream", "println", "(Ljava/lang/String;)V") <<
-      RETURN
-
-    codeHandler.freeze
-    classFile.writeToFile("./classfiles/HWGenerated.class")
-
-    System.out.println("written files.")
-  }
-}
diff --git a/src/main/scala/cafebabe/ClassFile.scala b/src/main/scala/cafebabe/ClassFile.scala
index 7fbde22..ee4a0ae 100644
--- a/src/main/scala/cafebabe/ClassFile.scala
+++ b/src/main/scala/cafebabe/ClassFile.scala
@@ -109,12 +109,9 @@ class ClassFile(val className: String, parentName: Option[String] = None) extend
 
   /** Loads the class using the current class loader. */
   def dynamicallyLoad : Unit = {
-    throw new Error("Not supported yet.")
-    /*
     val byteStream = (new ByteStream) << this
     val bytes : Array[Byte] = byteStream.getBytes
     CustomClassLoader.registerClass(className, bytes)
-    */
   }
 
   def toStream(byteStream: ByteStream): ByteStream = {
diff --git a/src/main/scala/cafebabe/Defaults.scala b/src/main/scala/cafebabe/Defaults.scala
index 3e5fcfd..2f1429b 100644
--- a/src/main/scala/cafebabe/Defaults.scala
+++ b/src/main/scala/cafebabe/Defaults.scala
@@ -8,7 +8,7 @@ object Defaults {
   val defaultMinor: U2 = 0
   val defaultMajor: U2 = 49 // J2SE 6.0=50, J2SE 5.0=49, JDK 1.4=48, JDK 1.3=47, JDK 1.2=46, JDK 1.1=45
 
-  val defaultClassAccessFlags: U2  = /* CLASS_ACC_PUBLIC | */ CLASS_ACC_SUPER
+  val defaultClassAccessFlags: U2  = CLASS_ACC_PUBLIC | CLASS_ACC_SUPER
   val defaultMethodAccessFlags: U2 = METHOD_ACC_PUBLIC
   val defaultFieldAccessFlags: U2  = FIELD_ACC_PROTECTED
 
diff --git a/src/test/scala/cafebabe/test/DynamicLoading.scala b/src/test/scala/cafebabe/test/DynamicLoading.scala
new file mode 100644
index 0000000..f82b584
--- /dev/null
+++ b/src/test/scala/cafebabe/test/DynamicLoading.scala
@@ -0,0 +1,25 @@
+package cafebabe.test
+
+import cafebabe._
+import cafebabe.ByteCodes._
+import cafebabe.AbstractByteCodes._
+
+import org.scalatest.FunSuite
+class DynamicLoading extends FunSuite {
+  test("DL 1") {
+    val cf = new ClassFile("MyTest", None)
+    cf.addDefaultConstructor
+    val ch = cf.addMethod("I", "plusOne", "I").codeHandler
+    ch << ILoad(1) << Ldc(1) << IADD << IRETURN
+    ch.freeze
+
+    cf.dynamicallyLoad
+    
+    val c = CustomClassLoader.loadClass("MyTest")
+    val o = c.newInstance().asInstanceOf[AnyRef]
+    val m = c.getMethod("plusOne", Integer.TYPE)
+    (m.invoke(o, 41 : java.lang.Integer) === 42)
+  }
+
+
+}