ENT-1906: Trivial tweaks to DJVM code. (corda#3890)

* Trivial tweaks to DJVM code.
  - Use ASM Type.getInternalName()
  - Use @JvmDefault annotation
  - Declare test base class as abstract
  - Ensure test Log4J configuration has precedence
  - Replace assert() with require()
  - Replace simple lambdas with function references
* Publish corda-djvm artifact.
* Migrate Utilities class into the CLI tool.
* Configure unit tests for console logging.

build.gradle

@@ -331,6 +331,7 @@ bintrayConfig {
             'corda-rpc',
             'corda-core',
             'corda-core-deterministic',
+            'corda-djvm',
             'corda',
             'corda-finance',
             'corda-node',

djvm/build.gradle

@@ -1,6 +1,10 @@
 plugins {
     id 'com.github.johnrengelman.shadow' version '2.0.4'
 }
+apply plugin: 'net.corda.plugins.publish-utils'
+apply plugin: 'com.jfrog.artifactory'
+
+description 'Corda deterministic JVM sandbox'
 
 ext {
     // Shaded version of ASM to avoid conflict with root project.
@@ -30,8 +34,8 @@ dependencies {
 jar.enabled = false
 
 shadowJar {
-    baseName = "djvm"
-    classifier = ""
+    baseName 'corda-djvm'
+    classifier ''
     dependencies {
         exclude(dependency('com.jcabi:.*:.*'))
         exclude(dependency('org.apache.*:.*:.*'))
@@ -40,10 +44,14 @@ shadowJar {
         exclude(dependency('io.github.lukehutch:.*:.*'))
     }
     relocate 'org.objectweb.asm', 'djvm.org.objectweb.asm'
-    artifacts {
-        shadow(tasks.shadowJar.archivePath) {
-            builtBy shadowJar
-        }
-    }
 }
 assemble.dependsOn shadowJar
+
+artifacts {
+    publish shadowJar
+}
+
+publish {
+    disableDefaultJar true
+    name shadowJar.baseName
+}

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/BuildCommand.kt

@@ -1,8 +1,5 @@
 package net.corda.djvm.tools.cli
 
-import net.corda.djvm.tools.Utilities.createCodePath
-import net.corda.djvm.tools.Utilities.getFileNames
-import net.corda.djvm.tools.Utilities.jarPath
 import picocli.CommandLine.Command
 import picocli.CommandLine.Parameters
 import java.nio.file.Path

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/ClassCommand.kt

@@ -7,9 +7,6 @@ import net.corda.djvm.execution.*
 import net.corda.djvm.references.ClassModule
 import net.corda.djvm.source.ClassSource
 import net.corda.djvm.source.SourceClassLoader
-import net.corda.djvm.tools.Utilities.find
-import net.corda.djvm.tools.Utilities.onEmpty
-import net.corda.djvm.tools.Utilities.userClassPath
 import net.corda.djvm.utilities.Discovery
 import djvm.org.objectweb.asm.ClassReader
 import picocli.CommandLine.Option

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/InspectionCommand.kt

@@ -1,7 +1,6 @@
 package net.corda.djvm.tools.cli
 
 import net.corda.djvm.source.ClassSource
-import net.corda.djvm.tools.Utilities.createCodePath
 import picocli.CommandLine.Command
 import picocli.CommandLine.Parameters
 import java.nio.file.Files

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/NewCommand.kt

@@ -1,9 +1,5 @@
 package net.corda.djvm.tools.cli
 
-import net.corda.djvm.tools.Utilities.baseName
-import net.corda.djvm.tools.Utilities.createCodePath
-import net.corda.djvm.tools.Utilities.getFiles
-import net.corda.djvm.tools.Utilities.openOptions
 import picocli.CommandLine.*
 import java.nio.file.Files
 import java.nio.file.Path

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/TreeCommand.kt

@@ -1,6 +1,5 @@
 package net.corda.djvm.tools.cli
 
-import net.corda.djvm.tools.Utilities.workingDirectory
 import picocli.CommandLine.Command
 import java.nio.file.Files
 

djvm/cli/src/main/kotlin/net/corda/djvm/tools/cli/Utilities.kt

@@ -0,0 +1,104 @@
+@file:JvmName("Utilities")
+package net.corda.djvm.tools.cli
+
+import io.github.lukehutch.fastclasspathscanner.FastClasspathScanner
+import java.lang.reflect.Modifier
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+import java.nio.file.StandardOpenOption
+
+/**
+ * Get the expanded file name of each path in the provided array.
+ */
+fun Array<Path>?.getFiles(map: (Path) -> Path = { it }) = (this ?: emptyArray()).map {
+    val pathString = it.toString()
+    val path = map(it)
+    when {
+        '/' in pathString || '\\' in pathString ->
+            throw Exception("Please provide a pathless file name")
+        pathString.endsWith(".java", true) -> path
+        else -> Paths.get("$path.java")
+    }
+}
+
+/**
+ * Get the string representation of each expanded file name in the provided array.
+ */
+fun Array<Path>?.getFileNames(map: (Path) -> Path = { it }) = this.getFiles(map).map {
+    it.toString()
+}.toTypedArray()
+
+/**
+ * Execute inlined action if the collection is empty.
+ */
+inline fun <T> List<T>.onEmpty(action: () -> Unit): List<T> {
+    if (!this.any()) {
+        action()
+    }
+    return this
+}
+
+/**
+ * Execute inlined action if the array is empty.
+ */
+inline fun <reified T> Array<T>?.onEmpty(action: () -> Unit): Array<T> {
+    return (this ?: emptyArray()).toList().onEmpty(action).toTypedArray()
+}
+
+/**
+ * Derive the set of [StandardOpenOption]'s to use for a file operation.
+ */
+fun openOptions(force: Boolean) = if (force) {
+    arrayOf(StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING)
+} else {
+    arrayOf(StandardOpenOption.CREATE_NEW)
+}
+
+/**
+ * Get the path of where any generated code will be placed. Create the directory if it does not exist.
+ */
+fun createCodePath(): Path {
+    return Paths.get("tmp", "net", "corda", "djvm").let {
+        Files.createDirectories(it)
+    }
+}
+
+/**
+ * Return the base name of a file (i.e., its name without extension)
+ */
+val Path.baseName: String
+    get() = this.fileName.toString()
+            .replaceAfterLast('.', "")
+            .removeSuffix(".")
+
+/**
+ * The path of the executing JAR.
+ */
+val jarPath: String = object {}.javaClass.protectionDomain.codeSource.location.toURI().path
+
+
+/**
+ * The path of the current working directory.
+ */
+val workingDirectory: Path = Paths.get(System.getProperty("user.dir"))
+
+/**
+ * The class path for the current execution context.
+ */
+val userClassPath: String = System.getProperty("java.class.path")
+
+/**
+ * Get a reference of each concrete class that implements interface or class [T].
+ */
+inline fun <reified T> find(scanSpec: String = "net/corda/djvm"): List<Class<*>> {
+    val references = mutableListOf<Class<*>>()
+    FastClasspathScanner(scanSpec)
+            .matchClassesImplementing(T::class.java) { clazz ->
+                if (!Modifier.isAbstract(clazz.modifiers) && !Modifier.isStatic(clazz.modifiers)) {
+                    references.add(clazz)
+                }
+            }
+            .scan()
+    return references
+}

djvm/src/main/kotlin/net/corda/djvm/code/Emitter.kt

@@ -20,6 +20,7 @@ interface Emitter {
     /**
      * Indication of whether or not the emitter performs instrumentation for tracing inside the sandbox.
      */
+    @JvmDefault
     val isTracer: Boolean
         get() = false
 

djvm/src/main/kotlin/net/corda/djvm/references/MemberInformation.kt

@@ -12,5 +12,6 @@ interface MemberInformation {
     val className: String
     val memberName: String
     val signature: String
+    @JvmDefault
     val reference: String get() = "$className.$memberName:$signature"
 }

djvm/src/main/kotlin/net/corda/djvm/rewiring/LoadedClass.kt

@@ -1,5 +1,7 @@
 package net.corda.djvm.rewiring
 
+import org.objectweb.asm.Type
+
 /**
  * A class or interface running in a Java application, together with its raw byte code representation and all references
  * made from within the type.
@@ -16,7 +18,7 @@ class LoadedClass(
      * The name of the loaded type.
      */
     val name: String
-        get() = type.name.replace('.', '/')
+        get() = Type.getInternalName(type)
 
     override fun toString(): String {
         return "Class(type=$name, size=${byteCode.bytes.size}, isModified=${byteCode.isModified})"

djvm/src/main/kotlin/net/corda/djvm/rewiring/SandboxClassWriter.kt

@@ -4,6 +4,7 @@ import org.objectweb.asm.ClassReader
 import org.objectweb.asm.ClassWriter
 import org.objectweb.asm.ClassWriter.COMPUTE_FRAMES
 import org.objectweb.asm.ClassWriter.COMPUTE_MAXS
+import org.objectweb.asm.Type
 
 /**
  * Class writer for sandbox execution, with configurable a [classLoader] to ensure correct deduction of the used class
@@ -52,7 +53,7 @@ open class SandboxClassWriter(
                 do {
                     clazz = clazz.superclass
                 } while (!clazz.isAssignableFrom(class2))
-                clazz.name.replace('.', '/')
+                Type.getInternalName(clazz)
             }
         }
     }

djvm/src/main/kotlin/net/corda/djvm/source/SourceClassLoader.kt

@@ -80,7 +80,7 @@ open class SourceClassLoader(
                 when {
                     !Files.exists(it) -> throw FileNotFoundException("File not found; $it")
                     Files.isDirectory(it) -> {
-                        listOf(it.toURL()) + Files.list(it).filter { isJarFile(it) }.map { it.toURL() }.toList()
+                        listOf(it.toURL()) + Files.list(it).filter(::isJarFile).map { it.toURL() }.toList()
                     }
                     Files.isReadable(it) && isJarFile(it) -> listOf(it.toURL())
                     else -> throw IllegalArgumentException("Expected JAR or class file, but found $it")

djvm/src/main/kotlin/net/corda/djvm/utilities/Discovery.kt

@@ -7,6 +7,7 @@ import java.lang.reflect.Modifier
  * Find and instantiate types that implement a certain interface.
  */
 object Discovery {
+    const val FORBIDDEN_CLASS_MASK = (Modifier.STATIC or Modifier.ABSTRACT)
 
     /**
      * Get an instance of each concrete class that implements interface or class [T].
@@ -15,7 +16,7 @@ object Discovery {
         val instances = mutableListOf<T>()
         FastClasspathScanner("net/corda/djvm")
                 .matchClassesImplementing(T::class.java) { clazz ->
-                    if (!Modifier.isAbstract(clazz.modifiers) && !Modifier.isStatic(clazz.modifiers)) {
+                    if (clazz.modifiers and FORBIDDEN_CLASS_MASK == 0) {
                         try {
                             instances.add(clazz.newInstance())
                         } catch (exception: Throwable) {

djvm/src/test/kotlin/foo/bar/sandbox/StrictFloat.kt

@@ -4,7 +4,7 @@ class StrictFloat : Callable {
     override fun call() {
         val d = java.lang.Double.MIN_VALUE
         val x = d / 2 * 2
-        assert(x.toString() == "0.0")
+        require(x.toString() == "0.0")
     }
 }