Add ability to override debugger info flags/parameter info flags

Add the ability to set the debugger info flags explicitly, and default to
enabling said flags by default to improve the diagnostic capabilities of
generated class files.

Adds the ability to override the default parameter info inclusion setting
on the compiler, and defaults to including by default to enrich further
reflection assertions.

Author: ascopes

java-compiler-testing/src/main/java/io/github/ascopes/jct/compilers/AbstractJctCompiler.java

@@ -32,6 +32,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 import javax.annotation.processing.Processor;
 import org.apiguardian.api.API;
 import org.apiguardian.api.API.Status;
@@ -79,6 +80,8 @@ public abstract class AbstractJctCompiler implements JctCompiler {
   private boolean inheritSystemModulePath;
   private LoggingMode fileManagerLoggingMode;
   private AnnotationProcessorDiscovery annotationProcessorDiscovery;
+  private Set<DebuggingInfo> debuggingInfo;
+  private boolean parameterInfoEnabled;
 
   /**
    * Initialize this compiler.
@@ -108,6 +111,8 @@ protected AbstractJctCompiler(String defaultName) {
     inheritSystemModulePath = JctCompiler.DEFAULT_INHERIT_SYSTEM_MODULE_PATH;
     fileManagerLoggingMode = JctCompiler.DEFAULT_FILE_MANAGER_LOGGING_MODE;
     annotationProcessorDiscovery = JctCompiler.DEFAULT_ANNOTATION_PROCESSOR_DISCOVERY;
+    debuggingInfo = DEFAULT_DEBUGGING_INFO;
+    parameterInfoEnabled = DEFAULT_PARAMETER_INFO_ENABLED;
   }
 
   @Override
@@ -417,6 +422,29 @@ public AbstractJctCompiler annotationProcessorDiscovery(
     return this;
   }
 
+  @Override
+  public Set<DebuggingInfo> getDebuggingInfo() {
+    return debuggingInfo;
+  }
+
+  @Override
+  public JctCompiler debuggingInfo(Set<DebuggingInfo> debuggingInfo) {
+    requireNonNullValues(debuggingInfo, "debuggingInfo");
+    this.debuggingInfo = Set.copyOf(debuggingInfo);
+    return this;
+  }
+
+  @Override
+  public boolean isParameterInfoEnabled() {
+    return parameterInfoEnabled;
+  }
+
+  @Override
+  public JctCompiler parameterInfoEnabled(boolean parameterInfoEnabled) {
+    this.parameterInfoEnabled = parameterInfoEnabled;
+    return this;
+  }
+
   /**
    * Get the string representation of the compiler.
    *
@@ -504,6 +532,8 @@ protected List<String> buildFlags(JctFlagBuilder flagBuilder) {
         .target(target)
         .verbose(verbose)
         .showWarnings(showWarnings)
+        .debuggingInfo(debuggingInfo)
+        .parameterInfoEnabled(parameterInfoEnabled)
         .build();
   }
 

java-compiler-testing/src/main/java/io/github/ascopes/jct/compilers/DebuggingInfo.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2022 - 2023, the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.github.ascopes.jct.compilers;
+
+import java.util.EnumSet;
+import java.util.Set;
+import org.apiguardian.api.API;
+import org.apiguardian.api.API.Status;
+
+/**
+ * An enum representing the various types of debugger info that can be included in compilations.
+ *
+ * <p>This corresponds to the {@code -g} flag in the OpenJDK Javac implementation.
+ *
+ * @author Ashley Scopes
+ * @since 3.0.0
+ */
+@API(since = "3.0.0", status = Status.STABLE)
+public enum DebuggingInfo {
+  LINES,
+  VARS,
+  SOURCE;
+
+  /**
+   * Return a set of none of the debugger info flags.
+   *
+   * @return a set containing no debugger flags.
+   */
+  public static Set<DebuggingInfo> none() {
+    return EnumSet.noneOf(DebuggingInfo.class);
+  }
+
+  /**
+   * Return a set of the given debugger info flags.
+   *
+   * @param flag  the first flag.
+   * @param flags additional flags.
+   * @return the set of the debugger info flags.
+   */
+  public static Set<DebuggingInfo> just(DebuggingInfo flag, DebuggingInfo... flags) {
+    return EnumSet.of(flag, flags);
+  }
+
+  /**
+   * Return a set of all the debugger info flags.
+   *
+   * @return a set containing all the debugger flags.
+   */
+  public static Set<DebuggingInfo> all() {
+    return EnumSet.allOf(DebuggingInfo.class);
+  }
+}