diff --git a/platform/lang-impl/src/com/intellij/lang/parser/GeneratedParserUtilBase.java b/platform/lang-impl/src/com/intellij/lang/parser/GeneratedParserUtilBase.java
index 705c80888091..05e7cf8e8b09 100644
--- a/platform/lang-impl/src/com/intellij/lang/parser/GeneratedParserUtilBase.java
+++ b/platform/lang-impl/src/com/intellij/lang/parser/GeneratedParserUtilBase.java
@@ -39,6 +39,7 @@ import com.intellij.util.Function;
 import com.intellij.util.PairProcessor;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.LimitedPool;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -92,6 +93,59 @@ public class GeneratedParserUtilBase {
     }
   };
 
+  public interface Hook<T> {
+
+    @Contract("_,null,_->null")
+    PsiBuilder.Marker run(PsiBuilder builder, PsiBuilder.Marker marker, T param);
+
+  }
+
+  public static final Hook<WhitespacesAndCommentsBinder> LEFT_BINDER =
+    new Hook<WhitespacesAndCommentsBinder>() {
+      @Override
+      public PsiBuilder.Marker run(PsiBuilder builder,
+                                   PsiBuilder.Marker marker,
+                                   WhitespacesAndCommentsBinder param) {
+        if (marker != null) marker.setCustomEdgeTokenBinders(param, null);
+        return marker;
+      }
+    };
+
+  public static final Hook<WhitespacesAndCommentsBinder> RIGHT_BINDER =
+    new Hook<WhitespacesAndCommentsBinder>() {
+      @Override
+      public PsiBuilder.Marker run(PsiBuilder builder,
+                                   PsiBuilder.Marker marker,
+                                   WhitespacesAndCommentsBinder param) {
+        if (marker != null) marker.setCustomEdgeTokenBinders(null, param);
+        return marker;
+      }
+    };
+
+  public static final Hook<WhitespacesAndCommentsBinder[]> WS_BINDERS =
+    new Hook<WhitespacesAndCommentsBinder[]>() {
+      @Override
+      public PsiBuilder.Marker run(PsiBuilder builder,
+                                   PsiBuilder.Marker marker,
+                                   WhitespacesAndCommentsBinder[] param) {
+        if (marker != null) marker.setCustomEdgeTokenBinders(param[0], param[1]);
+        return marker;
+      }
+    };
+
+  public static final Hook<String> LOG_HOOK = new Hook<String>() {
+    @Override
+    public PsiBuilder.Marker run(PsiBuilder builder, PsiBuilder.Marker marker, String param) {
+      PsiBuilderImpl.ProductionMarker m = (PsiBuilderImpl.ProductionMarker)marker;
+      int start = m == null ? builder.getCurrentOffset() : m.getStartOffset();
+      int end = m == null ? start : m.getEndOffset();
+      String prefix = "[" + start + ", " + end + "]" + (m == null ? "" : " " + m.getTokenType());
+      builder.mark().error(prefix + ": " + param);
+      return marker;
+    }
+  };
+
+
   public static boolean eof(PsiBuilder builder, int level) {
     return builder.eof();
   }
@@ -481,9 +535,35 @@ public class GeneratedParserUtilBase {
       close_frame_impl_(state, frame, builder, marker, elementType, result, pinned);
       exit_section_impl_(state, frame, builder, elementType, result, pinned, eatMore);
     }
+    if (state.hooks != null) {
+      run_hooks_impl_(builder, state, level, pinned || result ? elementType : null);
+    }
     state.FRAMES.recycle(frame);
   }
 
+  public static <T> void register_hook_(PsiBuilder builder, int level, Hook<T> hook, T param) {
+    ErrorState state = ErrorState.get(builder);
+    state.hooks = Hooks.concat(hook, param, level, state.hooks);
+  }
+
+  public static <T> void register_hook_(PsiBuilder builder, int level, Hook<T[]> hook, T... param) {
+    ErrorState state = ErrorState.get(builder);
+    state.hooks = Hooks.concat(hook, param, level, state.hooks);
+  }
+
+  private static void run_hooks_impl_(PsiBuilder builder, ErrorState state, int level, @Nullable IElementType elementType) {
+    PsiBuilder.Marker marker = elementType == null ? null : (PsiBuilder.Marker)builder.getLatestDoneMarker();
+    if (elementType != null && marker == null) {
+      builder.error("No expected done marker at offset " + builder.getCurrentOffset());
+    }
+    while (state.hooks != null && state.hooks.level >= level) {
+      if (state.hooks.level == level) {
+        marker = ((Hook<Object>)state.hooks.hook).run(builder, marker, state.hooks.param);
+      }
+      state.hooks = state.hooks.next;
+    }
+  }
+
   private static void exit_section_impl_(ErrorState state,
                                          Frame frame,
                                          PsiBuilder builder,
@@ -831,6 +911,7 @@ public class GeneratedParserUtilBase {
     int predicateCount;
     boolean predicateSign = true;
     boolean suppressErrors;
+    Hooks<?> hooks;
     public Frame currentFrame;
     public CompletionState completionState;
 
@@ -1042,6 +1123,24 @@ public class GeneratedParserUtilBase {
     }
   }
 
+  private static class Hooks<T> {
+    final Hook<T> hook;
+    final T param;
+    final int level;
+    final Hooks<?> next;
+
+    Hooks(Hook<T> hook, T param, int level, Hooks next) {
+      this.hook = hook;
+      this.param = param;
+      this.level = level;
+      this.next = next;
+    }
+
+    static <E> Hooks<E> concat(Hook<E> hook, E param, int level, Hooks<?> hooks) {
+      return new Hooks<E>(hook, param, level, hooks);
+    }
+  }
+
 
   private static final int MAX_CHILDREN_IN_TREE = 10;
   public static boolean parseAsTree(ErrorState state, final PsiBuilder builder, int level, final IElementType chunkType,