Simplify type outlines to not implement type.getDeclaringType() and type.getEnclosingType()

These methods are not used for matching purposes, so don't need to be maintained in outlines.
There is one use of type.isAnonymousType() in IAST, but this use is under a feature flag that
is off by default. To satisfy that use we provide a simple isAnonymousType() implementation
which is based on the '$number' convention for anonymous class names.

Note: if anything does touch type.getDeclaringType() / type.getEnclosingType() later on when
doing the final transformation then the outline type is automatically inflated to a full type.
(This is already the case for other methods that aren't available in type outlines.)

We also drop type.getClassFileVersion() from outlines for the same reason.

Author: mcculls

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/bytebuddy/outline/OutlineTypeParser.java

@@ -7,7 +7,6 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
-import net.bytebuddy.ClassFileVersion;
 import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.jar.asm.AnnotationVisitor;
 import net.bytebuddy.jar.asm.ClassReader;
@@ -34,17 +33,11 @@ public TypeDescription parse(Class<?> loadedType) {
 
     TypeOutline typeOutline =
         new TypeOutline(
-            ClassFileVersion.ofThisVm().getMinorMajorVersion(),
             loadedType.getModifiers(),
             loadedType.getName(),
             null != superClass ? superClass.getName() : null,
             extractTypeNames(loadedType.getInterfaces()));
 
-    Class<?> declaringClass = loadedType.getDeclaringClass();
-    if (null != declaringClass) {
-      typeOutline.declaredBy(declaringClass.getName());
-    }
-
     for (Annotation a : loadedType.getDeclaredAnnotations()) {
       typeOutline.declare(annotationOutline(Type.getDescriptor(a.annotationType())));
     }
@@ -91,7 +84,6 @@ static final class OutlineTypeExtractor extends ClassVisitor {
     TypeOutline typeOutline;
     FieldOutline fieldOutline;
     MethodOutline methodOutline;
-    boolean selfContained = true;
 
     OutlineTypeExtractor() {
       super(OpenedClassReader.ASM_API);
@@ -105,23 +97,7 @@ public void visit(
         String signature,
         String superName,
         String[] interfaces) {
-      typeOutline = new TypeOutline(version, access, name, superName, interfaces);
-    }
-
-    @Override
-    public void visitOuterClass(String owner, String name, String descriptor) {
-      selfContained = false;
-    }
-
-    @Override
-    public void visitInnerClass(String name, String outerName, String innerName, int access) {
-      if (typeOutline.getInternalName().equals(name)) {
-        if (null != outerName) {
-          typeOutline.declaredBy(outerName);
-        } else if (null == innerName && !selfContained) {
-          typeOutline.anonymousType();
-        }
-      }
+      typeOutline = new TypeOutline(access, name, superName, interfaces);
     }
 
     @Override

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/bytebuddy/outline/TypeFactory.java

@@ -384,8 +384,8 @@ public TypeList.Generic getInterfaces() {
     }
 
     @Override
-    public TypeDescription getDeclaringType() {
-      return outline().getDeclaringType();
+    public boolean isAnonymousType() {
+      return outline().isAnonymousType();
     }
 
     @Override

dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/bytebuddy/outline/TypeOutline.java

@@ -4,7 +4,6 @@
 
 import java.util.ArrayList;
 import java.util.List;
-import net.bytebuddy.ClassFileVersion;
 import net.bytebuddy.description.annotation.AnnotationDescription;
 import net.bytebuddy.description.annotation.AnnotationList;
 import net.bytebuddy.description.field.FieldDescription;
@@ -27,21 +26,17 @@ final class TypeOutline extends WithName {
   private static final MethodList<MethodDescription.InDefinedShape> NO_METHODS =
       new MethodList.Empty<>();
 
-  private final int classFileVersion;
   private final int modifiers;
   private final String superName;
   private final String[] interfaces;
-  private String declaringName;
-  private boolean anonymousType;
 
   private List<AnnotationDescription> declaredAnnotations;
 
   private final List<FieldDescription.InDefinedShape> declaredFields = new ArrayList<>();
   private final List<MethodDescription.InDefinedShape> declaredMethods = new ArrayList<>();
 
-  TypeOutline(int version, int access, String internalName, String superName, String[] interfaces) {
+  TypeOutline(int access, String internalName, String superName, String[] interfaces) {
     super(internalName.replace('/', '.'));
-    this.classFileVersion = version;
     this.modifiers = access & ALLOWED_TYPE_MODIFIERS;
     this.superName = superName;
     this.interfaces = interfaces;
@@ -72,19 +67,6 @@ public TypeList.Generic getInterfaces() {
     return new TypeList.Generic.Explicit(outlines);
   }
 
-  @Override
-  public TypeDescription getDeclaringType() {
-    if (null != declaringName) {
-      return findType(declaringName.replace('/', '.'));
-    }
-    return null;
-  }
-
-  @Override
-  public TypeDescription getEnclosingType() {
-    return getDeclaringType(); // equivalent for outline purposes
-  }
-
   @Override
   public int getModifiers() {
     return modifiers;
@@ -114,11 +96,6 @@ private boolean matchesMask(int mask) {
     return (this.getModifiers() & mask) == mask;
   }
 
-  @Override
-  public ClassFileVersion getClassFileVersion() {
-    return ClassFileVersion.ofMinorMajor(classFileVersion);
-  }
-
   @Override
   public AnnotationList getDeclaredAnnotations() {
     return null == declaredAnnotations
@@ -138,11 +115,17 @@ public MethodList<MethodDescription.InDefinedShape> getDeclaredMethods() {
 
   @Override
   public boolean isAnonymousType() {
-    return anonymousType;
-  }
-
-  void declaredBy(String declaringName) {
-    this.declaringName = declaringName;
+    // this method is only used when dd.iast.anonymous-classes.enabled=false
+    // so take simple approach and look for '$number' at the end of the name
+    for (int end = name.length() - 1, i = end; i > 0; i--) {
+      char c = name.charAt(i);
+      if (c == '$' && i < end) {
+        return true; // only seen digits so far, assume anonymous
+      } else if (c < '0' || c > '9') {
+        break; // non-digit character found, assume not anonymous
+      }
+    }
+    return false;
   }
 
   void declare(AnnotationDescription annotation) {
@@ -165,8 +148,4 @@ void declare(MethodDescription.InDefinedShape method) {
       declaredMethods.add(method);
     }
   }
-
-  void anonymousType() {
-    anonymousType = true;
-  }
 }