Add Capture Expressions

Previously watches, capture expressions allow to describe what exactly
 we want to capture and put into a snapshot for a log probe.
When one or more capture expressions is defined, only the capture
expressions are added to the Captures part of the snapshot.
Expressions can be complex using the expression language and must
return a value from which we start to capture the object graph
following the limits that can be defined per capture expressions.
A new attribute captureExpressions is added into the snapshot.

Author: jpbempel

dd-java-agent/agent-debugger/debugger-bootstrap/src/main/java/datadog/trace/bootstrap/debugger/CapturedContext.java

@@ -34,7 +34,7 @@ public class CapturedContext implements ValueReferenceResolver {
   private String thisClassName;
   private long duration;
   private final Map<String, Status> statusByProbeId = new LinkedHashMap<>();
-  private Map<String, CapturedValue> watches;
+  private Map<String, CapturedValue> captureExpressions;
 
   public CapturedContext() {}
 
@@ -260,8 +260,8 @@ public Map<String, CapturedValue> getStaticFields() {
     return staticFields;
   }
 
-  public Map<String, CapturedValue> getWatches() {
-    return watches;
+  public Map<String, CapturedValue> getCaptureExpressions() {
+    return captureExpressions;
   }
 
   public Limits getLimits() {
@@ -277,9 +277,9 @@ public String getThisClassName() {
    * instance representation into the corresponding string value.
    */
   public void freeze(TimeoutChecker timeoutChecker) {
-    if (watches != null) {
-      // freeze only watches
-      watches.values().forEach(capturedValue -> capturedValue.freeze(timeoutChecker));
+    if (captureExpressions != null) {
+      // freeze only capture expressions
+      captureExpressions.values().forEach(capturedValue -> capturedValue.freeze(timeoutChecker));
       return;
     }
     if (arguments != null) {
@@ -377,11 +377,11 @@ private void putInStaticFields(String name, CapturedValue value) {
     staticFields.put(name, value);
   }
 
-  public void addWatch(CapturedValue value) {
-    if (watches == null) {
-      watches = new HashMap<>();
+  public void addCaptureExpression(CapturedValue value) {
+    if (captureExpressions == null) {
+      captureExpressions = new HashMap<>();
     }
-    watches.put(value.name, value);
+    captureExpressions.put(value.name, value);
   }
 
   public static class Status {

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/probe/ExceptionProbe.java

@@ -46,7 +46,8 @@ public ExceptionProbe(
         // forcing a useless condition to be instrumented with captureEntry=false
         new ProbeCondition(DSL.when(DSL.TRUE), "true"),
         capture,
-        sampling);
+        sampling,
+        null);
     this.exceptionProbeManager = exceptionProbeManager;
     this.chainedExceptionIdx = chainedExceptionIdx;
   }