Remove legacy agent installer

dd-java-agent/agent-builder/src/main/java/datadog/trace/agent/tooling/AgentInstaller.java

@@ -189,12 +189,8 @@ public static ClassFileTransformer installBytebuddyAgent(
       }
     }
 
-    AbstractTransformerBuilder transformerBuilder;
-    if (InstrumenterConfig.get().isLegacyInstallerEnabled()) {
-      transformerBuilder = new LegacyTransformerBuilder(agentBuilder);
-    } else {
-      transformerBuilder = new CombiningTransformerBuilder(agentBuilder, maxInstrumentationId);
-    }
+    CombiningTransformerBuilder transformerBuilder =
+        new CombiningTransformerBuilder(agentBuilder, maxInstrumentationId);
 
     int installedCount = 0;
     for (Instrumenter instrumenter : instrumenters) {

dd-java-agent/agent-builder/src/main/java/datadog/trace/agent/tooling/CombiningTransformerBuilder.java

@@ -2,6 +2,9 @@
 
 import static datadog.trace.agent.tooling.bytebuddy.DDTransformers.defaultTransformers;
 import static datadog.trace.agent.tooling.bytebuddy.matcher.ClassLoaderMatchers.ANY_CLASS_LOADER;
+import static datadog.trace.agent.tooling.bytebuddy.matcher.ClassLoaderMatchers.hasClassNamed;
+import static datadog.trace.agent.tooling.bytebuddy.matcher.ClassLoaderMatchers.hasClassNamedOneOf;
+import static datadog.trace.agent.tooling.bytebuddy.matcher.HierarchyMatchers.declaresAnnotation;
 import static datadog.trace.agent.tooling.bytebuddy.matcher.NameMatchers.namedOneOf;
 import static net.bytebuddy.matcher.ElementMatchers.not;
 
@@ -14,19 +17,38 @@
 import datadog.trace.api.InstrumenterConfig;
 import java.lang.instrument.ClassFileTransformer;
 import java.lang.instrument.Instrumentation;
+import java.security.ProtectionDomain;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import net.bytebuddy.agent.builder.AgentBuilder;
 import net.bytebuddy.asm.Advice;
+import net.bytebuddy.asm.AsmVisitorWrapper;
 import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.DynamicType;
 import net.bytebuddy.matcher.ElementMatcher;
+import net.bytebuddy.utility.JavaModule;
 
 /** Builds multiple instrumentations into a single combining-matcher and splitting-transformer. */
-public final class CombiningTransformerBuilder extends AbstractTransformerBuilder {
+public final class CombiningTransformerBuilder
+    implements Instrumenter.TypeTransformer, Instrumenter.MethodTransformer {
+
+  // Added here instead of byte-buddy's ignores because it's relatively
+  // expensive. https://github.com/DataDog/dd-trace-java/pull/1045
+  private static final ElementMatcher.Junction<TypeDescription> NOT_DECORATOR_MATCHER =
+      not(
+          declaresAnnotation(
+              namedOneOf("javax.decorator.Decorator", "jakarta.decorator.Decorator")));
+
+  /** Associates context stores with the class-loader matchers to activate them. */
+  private final Map<Map.Entry<String, String>, ElementMatcher<ClassLoader>> contextStoreInjection =
+      new HashMap<>();
+
   private final AgentBuilder agentBuilder;
 
   private final List<MatchRecorder> matchers = new ArrayList<>();
@@ -52,8 +74,21 @@ public CombiningTransformerBuilder(AgentBuilder agentBuilder, int maxInstrumenta
     this.nextSupplementaryId = maxInstrumentationId + 1;
   }
 
-  @Override
-  protected void buildInstrumentation(InstrumenterModule module, Instrumenter member) {
+  public void applyInstrumentation(Instrumenter instrumenter) {
+    if (instrumenter instanceof InstrumenterModule) {
+      InstrumenterModule module = (InstrumenterModule) instrumenter;
+      if (module.isEnabled()) {
+        InstrumenterState.registerInstrumentation(module);
+        for (Instrumenter member : module.typeInstrumentations()) {
+          buildInstrumentation(module, member);
+        }
+      }
+    } else {
+      throw new IllegalArgumentException("Unexpected Instrumenter type");
+    }
+  }
+
+  private void buildInstrumentation(InstrumenterModule module, Instrumenter member) {
 
     int id = module.instrumentationId();
     if (module != member) {
@@ -161,8 +196,51 @@ public void applyAdvice(ElementMatcher<? super MethodDescription> matcher, Strin
             .advice(not(ignoredMethods).and(matcher), className));
   }
 
-  @Override
-  protected void applyContextStoreInjection(
+  /** Counts the number of distinct context store injections registered with this builder. */
+  private int contextStoreCount() {
+    return contextStoreInjection.size();
+  }
+
+  /** Applies each context store injection, guarded by the associated class-loader matcher. */
+  private void applyContextStoreInjection() {
+    contextStoreInjection.forEach(this::applyContextStoreInjection);
+  }
+
+  /** Tracks which class-loader matchers are associated with each store request. */
+  private void registerContextStoreInjection(
+      InstrumenterModule module, Instrumenter member, Map<String, String> contextStore) {
+    ElementMatcher<ClassLoader> activation;
+
+    if (member instanceof Instrumenter.ForBootstrap) {
+      activation = ANY_CLASS_LOADER;
+    } else if (member instanceof Instrumenter.ForTypeHierarchy) {
+      String hierarchyHint = ((Instrumenter.ForTypeHierarchy) member).hierarchyMarkerType();
+      activation = null != hierarchyHint ? hasClassNamed(hierarchyHint) : ANY_CLASS_LOADER;
+    } else if (member instanceof Instrumenter.ForSingleType) {
+      activation = hasClassNamed(((Instrumenter.ForSingleType) member).instrumentedType());
+    } else if (member instanceof Instrumenter.ForKnownTypes) {
+      activation = hasClassNamedOneOf(((Instrumenter.ForKnownTypes) member).knownMatchingTypes());
+    } else {
+      activation = ANY_CLASS_LOADER;
+    }
+
+    activation = requireBoth(activation, module.classLoaderMatcher());
+
+    for (Map.Entry<String, String> storeEntry : contextStore.entrySet()) {
+      ElementMatcher<ClassLoader> oldActivation = contextStoreInjection.get(storeEntry);
+      // optimization: treat 'any' as if there wasn't an old matcher
+      if (null == oldActivation || ANY_CLASS_LOADER == activation) {
+        contextStoreInjection.put(storeEntry, activation);
+      } else if (ANY_CLASS_LOADER != oldActivation) {
+        // store can be activated by either the old OR new matcher
+        contextStoreInjection.put(
+            storeEntry, new ElementMatcher.Junction.Disjunction<>(oldActivation, activation));
+      }
+    }
+  }
+
+  /** Arranges for a context value field to be injected into types extending the context key. */
+  private void applyContextStoreInjection(
       Map.Entry<String, String> contextStore, ElementMatcher<ClassLoader> activation) {
     String keyClassName = contextStore.getKey();
     String contextClassName = contextStore.getValue();
@@ -178,7 +256,6 @@ protected void applyContextStoreInjection(
     transformers[id] = new AdviceStack(new VisitingTransformer(contextAdvice));
   }
 
-  @Override
   public ClassFileTransformer installOn(Instrumentation instrumentation) {
     if (InstrumenterConfig.get().isRuntimeContextFieldInjection()) {
       // expand so we have enough space for a context injecting transformer for each store
@@ -193,4 +270,39 @@ public ClassFileTransformer installOn(Instrumentation instrumentation) {
         .transform(new SplittingTransformer(transformers))
         .installOn(instrumentation);
   }
+
+  static final class VisitingTransformer implements AgentBuilder.Transformer {
+    private final AsmVisitorWrapper visitor;
+
+    VisitingTransformer(AsmVisitorWrapper visitor) {
+      this.visitor = visitor;
+    }
+
+    @Override
+    public DynamicType.Builder<?> transform(
+        DynamicType.Builder<?> builder,
+        TypeDescription typeDescription,
+        ClassLoader classLoader,
+        JavaModule module,
+        ProtectionDomain pd) {
+      return builder.visit(visitor);
+    }
+  }
+
+  static final class HelperTransformer extends HelperInjector implements AgentBuilder.Transformer {
+    HelperTransformer(String requestingName, String... helperClassNames) {
+      super(requestingName, helperClassNames);
+    }
+  }
+
+  static ElementMatcher<ClassLoader> requireBoth(
+      ElementMatcher<ClassLoader> lhs, ElementMatcher<ClassLoader> rhs) {
+    if (ANY_CLASS_LOADER == lhs) {
+      return rhs;
+    } else if (ANY_CLASS_LOADER == rhs) {
+      return lhs;
+    } else {
+      return new ElementMatcher.Junction.Conjunction<>(lhs, rhs);
+    }
+  }
 }