[java-decompiler] IDEA-346312 adapt patches

- add comments with examples

GitOrigin-RevId: 22a84867e417c1a326f78c19d1146b3580f583a4

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/main/rels/MethodProcessorRunnable.java

@@ -268,6 +268,26 @@ public class MethodProcessorRunnable implements Runnable {
     return finished;
   }
 
+  /**
+   * Clean monitor of synchronizer: <p>
+   * Simple synthetic example:<p>
+   * before: <pre>
+   * {@code
+   * var a = b; // a is not used anywhere
+   * synchronized (b){
+   *  doSomething();
+   * }
+   * }
+   * </pre>
+   * after:
+   * <pre>
+   * {@code
+   * synchronized (b){
+   *  doSomething();
+   * }
+   * }
+   * </pre>
+   */
   public static void cleanSynchronizedVar(Statement stat) {
     for (Statement st : stat.getStats()) {
       cleanSynchronizedVar(st);

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/EliminateLoopsHelper.java

@@ -12,6 +12,30 @@ import java.util.*;
 
 public final class EliminateLoopsHelper {
 
+  /**
+   * Remove loops from the given root statement. <p>
+   * Simple synthetic example:<p>
+   * before: <pre>
+   * {@code
+   * LABEL:
+   * while(true){
+   *   while(true){
+   *     doSomething();
+   *     break LABEL;
+   *   }
+   * }
+   * }
+   * </pre>
+   * after:
+   * <pre>
+   * {@code
+   * while(true){
+   *   doSomething();
+   *   break;
+   * }
+   * }
+   * </pre>
+   */
   public static boolean eliminateLoops(RootStatement root, StructMethod mt, StructClass cl) {
 
     boolean ret = eliminateLoopsRec(root);

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/LoopExtractHelper.java

@@ -19,7 +19,29 @@ import java.util.Set;
 
 public final class LoopExtractHelper {
 
-
+  /**
+   * Analyzes the provided statement structure to identify and extract loop constructs.
+   * If any loops are successfully extracted, the statement sequences are condensed.<p>
+   * Simple synthetic example:<p>
+   * before: <pre>
+   * {@code
+   * while(true){
+   *  if (var1 >= 10){
+   *    break
+   *  }
+   *  doSomething();
+   * }
+   * }
+   * </pre>
+   * after:
+   * <pre>
+   * {@code
+   * while(var1 >= 10){
+   *  doSomething();
+   * }
+   * }
+   * </pre>
+   */
   public static boolean extractLoops(Statement root) {
 
     boolean res = (extractLoopsRec(root) != 0);

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/MergeHelper.java

@@ -17,6 +17,26 @@ import java.util.Set;
 import static org.jetbrains.java.decompiler.modules.decompiler.StatEdge.EdgeDirection;
 
 public final class MergeHelper {
+  /**
+   * Enhances the loops in the provided statement tree.
+   * Simple example:<p>
+   * before: <pre>
+   * {@code
+   * Iterator var6 = a.iterator();
+   * while(true) {
+   *  if (!var6.hasNext()) {
+   *    break;
+   *  }
+   *  A<String> s = (A)var6.next();
+   * }
+   * }
+   * </pre>
+   * after:
+   * <pre>
+   * {@code
+   * for(A<String> s : a) {}
+   * </pre>
+   */
   public static void enhanceLoops(Statement root) {
     while (enhanceLoopsRec(root)) /**/;
     SequenceHelper.condenseSequences(root);
@@ -714,6 +734,28 @@ public final class MergeHelper {
     return inv.isUnboxingCall() && isNextCall(inv.getInstance());
   }
 
+  /**
+   * Convert `while` to `do-while`.
+   * Simple synthetic example:<p>
+   * before: <pre>
+   * {@code
+   * while(true){
+   *   doSomething();
+   *   if (i >= 10) {
+   *     break;,
+   *   }
+   * }
+   * }
+   * </pre>
+   * after:
+   * <pre>
+   * {@code
+   * do {
+   *   doSomething();
+   * } while(i < 10);
+   * }
+   * </pre>
+   */
   public static boolean makeDoWhileLoops(RootStatement root) {
     if (makeDoWhileRec(root)) {
       SequenceHelper.condenseSequences(root);

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/TryHelper.java

@@ -20,6 +20,9 @@ import java.util.stream.Collectors;
 
 public final class TryHelper
 {
+  /**
+   * Tries to convert `try` statement to `try-with-resource`
+   */
   public static boolean enhanceTryStats(RootStatement root, StructMethod mt) {
     boolean ret = makeTryWithResourceRec(root, mt, root.getDummyExit(), new ArrayList<>());
     if (ret) {