Write multifile part->facade mapping to .kotlin_module

build-common/test/org/jetbrains/kotlin/serialization/jvm/DebugJvmPackageTable.java

@@ -1314,7 +1314,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1323,7 +1324,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     int getClassNameCount();
@@ -1331,7 +1333,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     java.lang.String getClassName(int index);
@@ -1339,11 +1342,78 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
         getClassNameBytes(int index);
+
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    java.util.List<java.lang.Integer> getMultifileFacadeIdList();
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    int getMultifileFacadeIdCount();
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    int getMultifileFacadeId(int index);
+
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    org.jetbrains.kotlin.protobuf.ProtocolStringList
+        getMultifileFacadeNameList();
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    int getMultifileFacadeNameCount();
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    java.lang.String getMultifileFacadeName(int index);
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    org.jetbrains.kotlin.protobuf.ByteString
+        getMultifileFacadeNameBytes(int index);
   }
   /**
    * Protobuf type {@code org.jetbrains.kotlin.serialization.jvm.PackageParts}
@@ -1412,6 +1482,36 @@ public final class DebugJvmPackageTable {
               className_.add(bs);
               break;
             }
+            case 24: {
+              if (!((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+                multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000004;
+              }
+              multifileFacadeId_.add(input.readInt32());
+              break;
+            }
+            case 26: {
+              int length = input.readRawVarint32();
+              int limit = input.pushLimit(length);
+              if (!((mutable_bitField0_ & 0x00000004) == 0x00000004) && input.getBytesUntilLimit() > 0) {
+                multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000004;
+              }
+              while (input.getBytesUntilLimit() > 0) {
+                multifileFacadeId_.add(input.readInt32());
+              }
+              input.popLimit(limit);
+              break;
+            }
+            case 34: {
+              org.jetbrains.kotlin.protobuf.ByteString bs = input.readBytes();
+              if (!((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+                multifileFacadeName_ = new org.jetbrains.kotlin.protobuf.LazyStringArrayList();
+                mutable_bitField0_ |= 0x00000008;
+              }
+              multifileFacadeName_.add(bs);
+              break;
+            }
           }
         }
       } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
@@ -1423,6 +1523,12 @@ public final class DebugJvmPackageTable {
         if (((mutable_bitField0_ & 0x00000002) == 0x00000002)) {
           className_ = className_.getUnmodifiableView();
         }
+        if (((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = java.util.Collections.unmodifiableList(multifileFacadeId_);
+        }
+        if (((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = multifileFacadeName_.getUnmodifiableView();
+        }
         this.unknownFields = unknownFields.build();
         makeExtensionsImmutable();
       }
@@ -1503,7 +1609,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1514,7 +1621,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public int getClassNameCount() {
@@ -1524,7 +1632,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public java.lang.String getClassName(int index) {
@@ -1534,7 +1643,8 @@ public final class DebugJvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
@@ -1542,9 +1652,97 @@ public final class DebugJvmPackageTable {
       return className_.getByteString(index);
     }
 
+    public static final int MULTIFILE_FACADE_ID_FIELD_NUMBER = 3;
+    private java.util.List<java.lang.Integer> multifileFacadeId_;
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public java.util.List<java.lang.Integer>
+        getMultifileFacadeIdList() {
+      return multifileFacadeId_;
+    }
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public int getMultifileFacadeIdCount() {
+      return multifileFacadeId_.size();
+    }
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public int getMultifileFacadeId(int index) {
+      return multifileFacadeId_.get(index);
+    }
+    private int multifileFacadeIdMemoizedSerializedSize = -1;
+
+    public static final int MULTIFILE_FACADE_NAME_FIELD_NUMBER = 4;
+    private org.jetbrains.kotlin.protobuf.LazyStringList multifileFacadeName_;
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public org.jetbrains.kotlin.protobuf.ProtocolStringList
+        getMultifileFacadeNameList() {
+      return multifileFacadeName_;
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public int getMultifileFacadeNameCount() {
+      return multifileFacadeName_.size();
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public java.lang.String getMultifileFacadeName(int index) {
+      return multifileFacadeName_.get(index);
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public org.jetbrains.kotlin.protobuf.ByteString
+        getMultifileFacadeNameBytes(int index) {
+      return multifileFacadeName_.getByteString(index);
+    }
+
     private void initFields() {
       packageFqName_ = "";
       className_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+      multifileFacadeId_ = java.util.Collections.emptyList();
+      multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -1569,6 +1767,16 @@ public final class DebugJvmPackageTable {
       for (int i = 0; i < className_.size(); i++) {
         output.writeBytes(2, className_.getByteString(i));
       }
+      if (getMultifileFacadeIdList().size() > 0) {
+        output.writeRawVarint32(26);
+        output.writeRawVarint32(multifileFacadeIdMemoizedSerializedSize);
+      }
+      for (int i = 0; i < multifileFacadeId_.size(); i++) {
+        output.writeInt32NoTag(multifileFacadeId_.get(i));
+      }
+      for (int i = 0; i < multifileFacadeName_.size(); i++) {
+        output.writeBytes(4, multifileFacadeName_.getByteString(i));
+      }
       getUnknownFields().writeTo(output);
     }
 
@@ -1591,6 +1799,29 @@ public final class DebugJvmPackageTable {
         size += dataSize;
         size += 1 * getClassNameList().size();
       }
+      {
+        int dataSize = 0;
+        for (int i = 0; i < multifileFacadeId_.size(); i++) {
+          dataSize += org.jetbrains.kotlin.protobuf.CodedOutputStream
+            .computeInt32SizeNoTag(multifileFacadeId_.get(i));
+        }
+        size += dataSize;
+        if (!getMultifileFacadeIdList().isEmpty()) {
+          size += 1;
+          size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+              .computeInt32SizeNoTag(dataSize);
+        }
+        multifileFacadeIdMemoizedSerializedSize = dataSize;
+      }
+      {
+        int dataSize = 0;
+        for (int i = 0; i < multifileFacadeName_.size(); i++) {
+          dataSize += org.jetbrains.kotlin.protobuf.CodedOutputStream
+            .computeBytesSizeNoTag(multifileFacadeName_.getByteString(i));
+        }
+        size += dataSize;
+        size += 1 * getMultifileFacadeNameList().size();
+      }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
       return size;
@@ -1712,6 +1943,10 @@ public final class DebugJvmPackageTable {
         bitField0_ = (bitField0_ & ~0x00000001);
         className_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
         bitField0_ = (bitField0_ & ~0x00000002);
+        multifileFacadeId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+        multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
         return this;
       }
 
@@ -1749,6 +1984,16 @@ public final class DebugJvmPackageTable {
           bitField0_ = (bitField0_ & ~0x00000002);
         }
         result.className_ = className_;
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = java.util.Collections.unmodifiableList(multifileFacadeId_);
+          bitField0_ = (bitField0_ & ~0x00000004);
+        }
+        result.multifileFacadeId_ = multifileFacadeId_;
+        if (((bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = multifileFacadeName_.getUnmodifiableView();
+          bitField0_ = (bitField0_ & ~0x00000008);
+        }
+        result.multifileFacadeName_ = multifileFacadeName_;
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -1780,6 +2025,26 @@ public final class DebugJvmPackageTable {
           }
           onChanged();
         }
+        if (!other.multifileFacadeId_.isEmpty()) {
+          if (multifileFacadeId_.isEmpty()) {
+            multifileFacadeId_ = other.multifileFacadeId_;
+            bitField0_ = (bitField0_ & ~0x00000004);
+          } else {
+            ensureMultifileFacadeIdIsMutable();
+            multifileFacadeId_.addAll(other.multifileFacadeId_);
+          }
+          onChanged();
+        }
+        if (!other.multifileFacadeName_.isEmpty()) {
+          if (multifileFacadeName_.isEmpty()) {
+            multifileFacadeName_ = other.multifileFacadeName_;
+            bitField0_ = (bitField0_ & ~0x00000008);
+          } else {
+            ensureMultifileFacadeNameIsMutable();
+            multifileFacadeName_.addAll(other.multifileFacadeName_);
+          }
+          onChanged();
+        }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
@@ -1898,7 +2163,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1909,7 +2175,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public int getClassNameCount() {
@@ -1919,7 +2186,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public java.lang.String getClassName(int index) {
@@ -1929,7 +2197,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
@@ -1940,7 +2209,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder setClassName(
@@ -1957,7 +2227,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addClassName(
@@ -1974,7 +2245,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addAllClassName(
@@ -1989,7 +2261,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder clearClassName() {
@@ -2002,7 +2275,8 @@ public final class DebugJvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addClassNameBytes(
@@ -2016,6 +2290,243 @@ public final class DebugJvmPackageTable {
         return this;
       }
 
+      private java.util.List<java.lang.Integer> multifileFacadeId_ = java.util.Collections.emptyList();
+      private void ensureMultifileFacadeIdIsMutable() {
+        if (!((bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>(multifileFacadeId_);
+          bitField0_ |= 0x00000004;
+         }
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public java.util.List<java.lang.Integer>
+          getMultifileFacadeIdList() {
+        return java.util.Collections.unmodifiableList(multifileFacadeId_);
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public int getMultifileFacadeIdCount() {
+        return multifileFacadeId_.size();
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public int getMultifileFacadeId(int index) {
+        return multifileFacadeId_.get(index);
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder setMultifileFacadeId(
+          int index, int value) {
+        ensureMultifileFacadeIdIsMutable();
+        multifileFacadeId_.set(index, value);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder addMultifileFacadeId(int value) {
+        ensureMultifileFacadeIdIsMutable();
+        multifileFacadeId_.add(value);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder addAllMultifileFacadeId(
+          java.lang.Iterable<? extends java.lang.Integer> values) {
+        ensureMultifileFacadeIdIsMutable();
+        org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+            values, multifileFacadeId_);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder clearMultifileFacadeId() {
+        multifileFacadeId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+        onChanged();
+        return this;
+      }
+
+      private org.jetbrains.kotlin.protobuf.LazyStringList multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+      private void ensureMultifileFacadeNameIsMutable() {
+        if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = new org.jetbrains.kotlin.protobuf.LazyStringArrayList(multifileFacadeName_);
+          bitField0_ |= 0x00000008;
+         }
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public org.jetbrains.kotlin.protobuf.ProtocolStringList
+          getMultifileFacadeNameList() {
+        return multifileFacadeName_.getUnmodifiableView();
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public int getMultifileFacadeNameCount() {
+        return multifileFacadeName_.size();
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public java.lang.String getMultifileFacadeName(int index) {
+        return multifileFacadeName_.get(index);
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public org.jetbrains.kotlin.protobuf.ByteString
+          getMultifileFacadeNameBytes(int index) {
+        return multifileFacadeName_.getByteString(index);
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder setMultifileFacadeName(
+          int index, java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.set(index, value);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addMultifileFacadeName(
+          java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.add(value);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addAllMultifileFacadeName(
+          java.lang.Iterable<java.lang.String> values) {
+        ensureMultifileFacadeNameIsMutable();
+        org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+            values, multifileFacadeName_);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder clearMultifileFacadeName() {
+        multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addMultifileFacadeNameBytes(
+          org.jetbrains.kotlin.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.add(value);
+        onChanged();
+        return this;
+      }
+
       // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.serialization.jvm.PackageParts)
     }
 
@@ -2052,9 +2563,11 @@ public final class DebugJvmPackageTable {
       "\022K\n\rpackage_parts\030\001 \003(\01324.org.jetbrains." +
       "kotlin.serialization.jvm.PackageParts\022L\n" +
       "\016metadata_parts\030\002 \003(\01324.org.jetbrains.ko" +
-      "tlin.serialization.jvm.PackageParts\";\n\014P" +
+      "tlin.serialization.jvm.PackageParts\"{\n\014P" +
       "ackageParts\022\027\n\017package_fq_name\030\001 \002(\t\022\022\n\n" +
-      "class_name\030\002 \003(\tB\026B\024DebugJvmPackageTable"
+      "class_name\030\002 \003(\t\022\037\n\023multifile_facade_id\030" +
+      "\003 \003(\005B\002\020\001\022\035\n\025multifile_facade_name\030\004 \003(\t",
+      "B\026B\024DebugJvmPackageTable"
     };
     org.jetbrains.kotlin.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
         new org.jetbrains.kotlin.protobuf.Descriptors.FileDescriptor.    InternalDescriptorAssigner() {
@@ -2079,7 +2592,7 @@ public final class DebugJvmPackageTable {
     internal_static_org_jetbrains_kotlin_serialization_jvm_PackageParts_fieldAccessorTable = new
       org.jetbrains.kotlin.protobuf.GeneratedMessage.FieldAccessorTable(
         internal_static_org_jetbrains_kotlin_serialization_jvm_PackageParts_descriptor,
-        new java.lang.String[] { "PackageFqName", "ClassName", });
+        new java.lang.String[] { "PackageFqName", "ClassName", "MultifileFacadeId", "MultifileFacadeName", });
   }
 
   // @@protoc_insertion_point(outer_class_scope)

compiler/backend/src/org/jetbrains/kotlin/codegen/ClassFileFactory.java

@@ -185,13 +185,13 @@ public class ClassFileFactory implements OutputFileCollection {
         final String packageFqNameAsString = packageFqName.asString();
         return new PackagePartRegistry() {
             @Override
-            public void addPart(@NotNull String partShortName) {
+            public void addPart(@NotNull String partShortName, @Nullable String facadeShortName) {
                 PackageParts packageParts = partsGroupedByPackage.get(packageFqNameAsString);
                 if (packageParts == null) {
                     packageParts = new PackageParts(packageFqNameAsString);
                     partsGroupedByPackage.put(packageFqNameAsString, packageParts);
                 }
-                packageParts.addPart(partShortName);
+                packageParts.addPart(partShortName, facadeShortName);
             }
         };
     }

compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassCodegen.kt

@@ -215,14 +215,13 @@ class MultifileClassCodegenImpl(
 
         if (!state.generateDeclaredClassFilter.shouldGeneratePackagePart(file) || !file.hasDeclarationsForPartClass()) return
 
-        val partInternalName = partType.internalName
+        packagePartRegistry.addPart(partType.internalName.substringAfterLast('/'), facadeClassType.internalName.substringAfterLast('/'))
-        packagePartRegistry.addPart(partInternalName.substring(partInternalName.lastIndexOf('/') + 1))
 
         val builder = state.factory.newVisitor(MultifileClassPart(file, packageFragment), partType, file)
 
         MultifileClassPartCodegen(
                 builder, file, packageFragment,
-                getSuperClassForPart(partInternalName),
+                getSuperClassForPart(partType.internalName),
                 shouldGeneratePartHierarchy,
                 partContext, state
         ).generate()

compiler/backend/src/org/jetbrains/kotlin/codegen/PackageCodegenImpl.java

@@ -20,6 +20,7 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.SmartList;
+import kotlin.text.StringsKt;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.codegen.context.PackageContext;
@@ -125,7 +126,7 @@ public class PackageCodegenImpl implements PackageCodegen {
         if (!generatePackagePart || !state.getGenerateDeclaredClassFilter().shouldGeneratePackagePart(file)) return;
 
         String name = fileClassType.getInternalName();
-        packagePartRegistry.addPart(name.substring(name.lastIndexOf('/') + 1));
+        packagePartRegistry.addPart(StringsKt.substringAfterLast(name, '/', name), null);
 
         ClassBuilder builder = state.getFactory().newVisitor(JvmDeclarationOriginKt.PackagePart(file, packageFragment), fileClassType, file);
 

compiler/backend/src/org/jetbrains/kotlin/codegen/PackagePartRegistry.kt

@@ -17,5 +17,5 @@
 package org.jetbrains.kotlin.codegen
 
 interface PackagePartRegistry {
-    fun addPart(partShortName: String)
+    fun addPart(partShortName: String, facadeShortName: String?)
 }

core/descriptor.loader.java/src/jvm_package_table.proto

@@ -30,6 +30,15 @@ message PackageTable {
 message PackageParts {
     required string package_fq_name = 1;
 
-    // Short names of files, without extension, present in this package
+    // Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+    // (multi-file facades are not present in this list, they are defined below)
     repeated string class_name = 2;
+
+    // For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+    // or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+    // (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+    repeated int32 multifile_facade_id = 3 [packed=true];
+
+    // Short names of multi-file facades, used in multifile_facade_id to store the part -> facade mapping.
+    repeated string multifile_facade_name = 4;
 }

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/ModuleMapping.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.load.kotlin
 import org.jetbrains.kotlin.serialization.jvm.JvmPackageTable
 import java.io.ByteArrayInputStream
 import java.io.DataInputStream
+import kotlin.comparisons.nullsLast
 
 class ModuleMapping private constructor(val packageFqName2Parts: Map<String, PackageParts>, private val debugName: String) {
     fun findPackageParts(packageFqName: String): PackageParts? {
@@ -43,14 +44,23 @@ class ModuleMapping private constructor(val packageFqName2Parts: Map<String, Pac
             val version = JvmMetadataVersion(*IntArray(stream.readInt()) { stream.readInt() })
 
             if (version.isCompatible()) {
-                val parseFrom = JvmPackageTable.PackageTable.parseFrom(stream)
+                val table = JvmPackageTable.PackageTable.parseFrom(stream) ?: return EMPTY
-                if (parseFrom != null) {
+                val result = hashMapOf<String, PackageParts>()
-                    val packageFqNameParts = hashMapOf<String, PackageParts>().apply {
+
-                        addParts(this, parseFrom.packagePartsList, PackageParts::addPart)
+                for (proto in table.packagePartsList) {
-                        addParts(this, parseFrom.metadataPartsList, PackageParts::addMetadataPart)
+                    val packageParts = result.getOrPut(proto.packageFqName) { PackageParts(proto.packageFqName) }
+                    for ((index, partShortName) in proto.classNameList.withIndex()) {
+                        val multifileFacadeId = proto.multifileFacadeIdList.getOrNull(index)?.minus(1)
+                        packageParts.addPart(partShortName, multifileFacadeId?.let(proto.multifileFacadeNameList::getOrNull))
                     }
-                    return ModuleMapping(packageFqNameParts, debugName ?: "<unknown>")
                 }
+
+                for (proto in table.metadataPartsList) {
+                    val packageParts = result.getOrPut(proto.packageFqName) { PackageParts(proto.packageFqName) }
+                    proto.classNameList.forEach(packageParts::addMetadataPart)
+                }
+
+                return ModuleMapping(result, debugName ?: "<unknown>")
             }
             else {
                 // TODO: consider reporting "incompatible ABI version" error for package parts
@@ -58,47 +68,52 @@ class ModuleMapping private constructor(val packageFqName2Parts: Map<String, Pac
 
             return EMPTY
         }
-
-        private inline fun addParts(
-                result: MutableMap<String, PackageParts>,
-                partsList: List<JvmPackageTable.PackageParts>,
-                addPartOrMetadataPart: (PackageParts, String) -> Unit
-        ) {
-            for (proto in partsList) {
-                PackageParts(proto.packageFqName).apply {
-                    result.put(proto.packageFqName, this)
-                    proto.classNameList.forEach { addPartOrMetadataPart(this, it) }
-                }
-            }
-        }
     }
 }
 
 class PackageParts(val packageFqName: String) {
-    // See JvmPackageTable.PackageTable.package_parts
+    // Short name of package part -> short name of the corresponding multifile facade (or null, if it's not a multifile part)
-    val parts: Set<String> = linkedSetOf<String>()
+    private val packageParts = linkedMapOf<String, String?>()
-    // See JvmPackageTable.PackageTable.metadata_parts
-    val metadataParts: Set<String> = linkedSetOf<String>()
 
-    fun addPart(shortName: String) {
+    // See JvmPackageTable.PackageTable.package_parts
-        (parts as MutableSet /* see KT-14663 */).add(shortName)
+    val parts: Set<String> get() = packageParts.keys
+    // See JvmPackageTable.PackageTable.metadata_parts
+    val metadataParts: Set<String> = linkedSetOf()
+
+    fun addPart(partShortName: String, facadeShortName: String?) {
+        packageParts[partShortName] = facadeShortName
     }
 
     fun removePart(shortName: String) {
-        (parts as MutableSet).remove(shortName)
+        packageParts.remove(shortName)
     }
 
     fun addMetadataPart(shortName: String) {
-        (metadataParts as MutableSet).add(shortName)
+        (metadataParts as MutableSet /* see KT-14663 */).add(shortName)
     }
 
     fun addTo(builder: JvmPackageTable.PackageTable.Builder) {
         if (parts.isNotEmpty()) {
             builder.addPackageParts(JvmPackageTable.PackageParts.newBuilder().apply {
                 packageFqName = this@PackageParts.packageFqName
-                addAllClassName(parts.sorted())
+
+                val facadeNameToId = mutableMapOf<String, Int>()
+                for ((facadeName, partNames) in parts.groupBy { getMultifileFacadeName(it) }.toSortedMap(nullsLast())) {
+                    for (partName in partNames.sorted()) {
+                        addClassName(partName)
+                        if (facadeName != null) {
+                            addMultifileFacadeId(1 + facadeNameToId.getOrPut(facadeName) { facadeNameToId.size })
+                        }
+                    }
+                }
+
+                for ((facadeId, facadeName) in facadeNameToId.values.zip(facadeNameToId.keys).sortedBy(Pair<Int, String>::first)) {
+                    assert(facadeId == multifileFacadeNameCount) { "Multifile facades are loaded incorrectly: $facadeNameToId" }
+                    addMultifileFacadeName(facadeName)
+                }
             })
         }
+
         if (metadataParts.isNotEmpty()) {
             builder.addMetadataParts(JvmPackageTable.PackageParts.newBuilder().apply {
                 packageFqName = this@PackageParts.packageFqName
@@ -107,16 +122,21 @@ class PackageParts(val packageFqName: String) {
         }
     }
 
+    fun getMultifileFacadeName(partShortName: String): String? = packageParts[partShortName]
+
     operator fun plusAssign(other: PackageParts) {
-        other.parts.forEach(this::addPart)
+        for ((partShortName, facadeShortName) in other.packageParts) {
+            addPart(partShortName, facadeShortName)
+        }
         other.metadataParts.forEach(this::addMetadataPart)
     }
 
     override fun equals(other: Any?) =
-            other is PackageParts && other.packageFqName == packageFqName && other.parts == parts && other.metadataParts == metadataParts
+            other is PackageParts &&
+            other.packageFqName == packageFqName && other.packageParts == packageParts && other.metadataParts == metadataParts
 
     override fun hashCode() =
-            (packageFqName.hashCode() * 31 + parts.hashCode()) * 31 + metadataParts.hashCode()
+            (packageFqName.hashCode() * 31 + packageParts.hashCode()) * 31 + metadataParts.hashCode()
 
     override fun toString() =
             (parts + metadataParts).toString()

core/descriptor.loader.java/src/org/jetbrains/kotlin/serialization/jvm/JvmPackageTable.java

@@ -905,7 +905,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -914,7 +915,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     int getClassNameCount();
@@ -922,7 +924,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     java.lang.String getClassName(int index);
@@ -930,11 +933,78 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     org.jetbrains.kotlin.protobuf.ByteString
         getClassNameBytes(int index);
+
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    java.util.List<java.lang.Integer> getMultifileFacadeIdList();
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    int getMultifileFacadeIdCount();
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    int getMultifileFacadeId(int index);
+
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    org.jetbrains.kotlin.protobuf.ProtocolStringList
+        getMultifileFacadeNameList();
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    int getMultifileFacadeNameCount();
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    java.lang.String getMultifileFacadeName(int index);
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    org.jetbrains.kotlin.protobuf.ByteString
+        getMultifileFacadeNameBytes(int index);
   }
   /**
    * Protobuf type {@code org.jetbrains.kotlin.serialization.jvm.PackageParts}
@@ -1001,6 +1071,36 @@ public final class JvmPackageTable {
               className_.add(bs);
               break;
             }
+            case 24: {
+              if (!((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+                multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000004;
+              }
+              multifileFacadeId_.add(input.readInt32());
+              break;
+            }
+            case 26: {
+              int length = input.readRawVarint32();
+              int limit = input.pushLimit(length);
+              if (!((mutable_bitField0_ & 0x00000004) == 0x00000004) && input.getBytesUntilLimit() > 0) {
+                multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>();
+                mutable_bitField0_ |= 0x00000004;
+              }
+              while (input.getBytesUntilLimit() > 0) {
+                multifileFacadeId_.add(input.readInt32());
+              }
+              input.popLimit(limit);
+              break;
+            }
+            case 34: {
+              org.jetbrains.kotlin.protobuf.ByteString bs = input.readBytes();
+              if (!((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+                multifileFacadeName_ = new org.jetbrains.kotlin.protobuf.LazyStringArrayList();
+                mutable_bitField0_ |= 0x00000008;
+              }
+              multifileFacadeName_.add(bs);
+              break;
+            }
           }
         }
       } catch (org.jetbrains.kotlin.protobuf.InvalidProtocolBufferException e) {
@@ -1012,6 +1112,12 @@ public final class JvmPackageTable {
         if (((mutable_bitField0_ & 0x00000002) == 0x00000002)) {
           className_ = className_.getUnmodifiableView();
         }
+        if (((mutable_bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = java.util.Collections.unmodifiableList(multifileFacadeId_);
+        }
+        if (((mutable_bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = multifileFacadeName_.getUnmodifiableView();
+        }
         try {
           unknownFieldsCodedOutput.flush();
         } catch (java.io.IOException e) {
@@ -1086,7 +1192,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1097,7 +1204,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public int getClassNameCount() {
@@ -1107,7 +1215,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public java.lang.String getClassName(int index) {
@@ -1117,7 +1226,8 @@ public final class JvmPackageTable {
      * <code>repeated string class_name = 2;</code>
      *
      * <pre>
-     * Short names of files, without extension, present in this package
+     * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+     * (multi-file facades are not present in this list, they are defined below)
      * </pre>
      */
     public org.jetbrains.kotlin.protobuf.ByteString
@@ -1125,9 +1235,97 @@ public final class JvmPackageTable {
       return className_.getByteString(index);
     }
 
+    public static final int MULTIFILE_FACADE_ID_FIELD_NUMBER = 3;
+    private java.util.List<java.lang.Integer> multifileFacadeId_;
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public java.util.List<java.lang.Integer>
+        getMultifileFacadeIdList() {
+      return multifileFacadeId_;
+    }
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public int getMultifileFacadeIdCount() {
+      return multifileFacadeId_.size();
+    }
+    /**
+     * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+     *
+     * <pre>
+     * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+     * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+     * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+     * </pre>
+     */
+    public int getMultifileFacadeId(int index) {
+      return multifileFacadeId_.get(index);
+    }
+    private int multifileFacadeIdMemoizedSerializedSize = -1;
+
+    public static final int MULTIFILE_FACADE_NAME_FIELD_NUMBER = 4;
+    private org.jetbrains.kotlin.protobuf.LazyStringList multifileFacadeName_;
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public org.jetbrains.kotlin.protobuf.ProtocolStringList
+        getMultifileFacadeNameList() {
+      return multifileFacadeName_;
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public int getMultifileFacadeNameCount() {
+      return multifileFacadeName_.size();
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public java.lang.String getMultifileFacadeName(int index) {
+      return multifileFacadeName_.get(index);
+    }
+    /**
+     * <code>repeated string multifile_facade_name = 4;</code>
+     *
+     * <pre>
+     * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+     * </pre>
+     */
+    public org.jetbrains.kotlin.protobuf.ByteString
+        getMultifileFacadeNameBytes(int index) {
+      return multifileFacadeName_.getByteString(index);
+    }
+
     private void initFields() {
       packageFqName_ = "";
       className_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+      multifileFacadeId_ = java.util.Collections.emptyList();
+      multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -1152,6 +1350,16 @@ public final class JvmPackageTable {
       for (int i = 0; i < className_.size(); i++) {
         output.writeBytes(2, className_.getByteString(i));
       }
+      if (getMultifileFacadeIdList().size() > 0) {
+        output.writeRawVarint32(26);
+        output.writeRawVarint32(multifileFacadeIdMemoizedSerializedSize);
+      }
+      for (int i = 0; i < multifileFacadeId_.size(); i++) {
+        output.writeInt32NoTag(multifileFacadeId_.get(i));
+      }
+      for (int i = 0; i < multifileFacadeName_.size(); i++) {
+        output.writeBytes(4, multifileFacadeName_.getByteString(i));
+      }
       output.writeRawBytes(unknownFields);
     }
 
@@ -1174,6 +1382,29 @@ public final class JvmPackageTable {
         size += dataSize;
         size += 1 * getClassNameList().size();
       }
+      {
+        int dataSize = 0;
+        for (int i = 0; i < multifileFacadeId_.size(); i++) {
+          dataSize += org.jetbrains.kotlin.protobuf.CodedOutputStream
+            .computeInt32SizeNoTag(multifileFacadeId_.get(i));
+        }
+        size += dataSize;
+        if (!getMultifileFacadeIdList().isEmpty()) {
+          size += 1;
+          size += org.jetbrains.kotlin.protobuf.CodedOutputStream
+              .computeInt32SizeNoTag(dataSize);
+        }
+        multifileFacadeIdMemoizedSerializedSize = dataSize;
+      }
+      {
+        int dataSize = 0;
+        for (int i = 0; i < multifileFacadeName_.size(); i++) {
+          dataSize += org.jetbrains.kotlin.protobuf.CodedOutputStream
+            .computeBytesSizeNoTag(multifileFacadeName_.getByteString(i));
+        }
+        size += dataSize;
+        size += 1 * getMultifileFacadeNameList().size();
+      }
       size += unknownFields.size();
       memoizedSerializedSize = size;
       return size;
@@ -1272,6 +1503,10 @@ public final class JvmPackageTable {
         bitField0_ = (bitField0_ & ~0x00000001);
         className_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
         bitField0_ = (bitField0_ & ~0x00000002);
+        multifileFacadeId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+        multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
         return this;
       }
 
@@ -1304,6 +1539,16 @@ public final class JvmPackageTable {
           bitField0_ = (bitField0_ & ~0x00000002);
         }
         result.className_ = className_;
+        if (((bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = java.util.Collections.unmodifiableList(multifileFacadeId_);
+          bitField0_ = (bitField0_ & ~0x00000004);
+        }
+        result.multifileFacadeId_ = multifileFacadeId_;
+        if (((bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = multifileFacadeName_.getUnmodifiableView();
+          bitField0_ = (bitField0_ & ~0x00000008);
+        }
+        result.multifileFacadeName_ = multifileFacadeName_;
         result.bitField0_ = to_bitField0_;
         return result;
       }
@@ -1324,6 +1569,26 @@ public final class JvmPackageTable {
             className_.addAll(other.className_);
           }
           
+        }
+        if (!other.multifileFacadeId_.isEmpty()) {
+          if (multifileFacadeId_.isEmpty()) {
+            multifileFacadeId_ = other.multifileFacadeId_;
+            bitField0_ = (bitField0_ & ~0x00000004);
+          } else {
+            ensureMultifileFacadeIdIsMutable();
+            multifileFacadeId_.addAll(other.multifileFacadeId_);
+          }
+          
+        }
+        if (!other.multifileFacadeName_.isEmpty()) {
+          if (multifileFacadeName_.isEmpty()) {
+            multifileFacadeName_ = other.multifileFacadeName_;
+            bitField0_ = (bitField0_ & ~0x00000008);
+          } else {
+            ensureMultifileFacadeNameIsMutable();
+            multifileFacadeName_.addAll(other.multifileFacadeName_);
+          }
+          
         }
         setUnknownFields(
             getUnknownFields().concat(other.unknownFields));
@@ -1444,7 +1709,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ProtocolStringList
@@ -1455,7 +1721,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public int getClassNameCount() {
@@ -1465,7 +1732,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public java.lang.String getClassName(int index) {
@@ -1475,7 +1743,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public org.jetbrains.kotlin.protobuf.ByteString
@@ -1486,7 +1755,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder setClassName(
@@ -1503,7 +1773,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addClassName(
@@ -1520,7 +1791,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addAllClassName(
@@ -1535,7 +1807,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder clearClassName() {
@@ -1548,7 +1821,8 @@ public final class JvmPackageTable {
        * <code>repeated string class_name = 2;</code>
        *
        * <pre>
-       * Short names of files, without extension, present in this package
+       * Short names of files, without extension, present in this package. Only single file facades and multi-file _parts_ are listed here
+       * (multi-file facades are not present in this list, they are defined below)
        * </pre>
        */
       public Builder addClassNameBytes(
@@ -1562,6 +1836,243 @@ public final class JvmPackageTable {
         return this;
       }
 
+      private java.util.List<java.lang.Integer> multifileFacadeId_ = java.util.Collections.emptyList();
+      private void ensureMultifileFacadeIdIsMutable() {
+        if (!((bitField0_ & 0x00000004) == 0x00000004)) {
+          multifileFacadeId_ = new java.util.ArrayList<java.lang.Integer>(multifileFacadeId_);
+          bitField0_ |= 0x00000004;
+         }
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public java.util.List<java.lang.Integer>
+          getMultifileFacadeIdList() {
+        return java.util.Collections.unmodifiableList(multifileFacadeId_);
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public int getMultifileFacadeIdCount() {
+        return multifileFacadeId_.size();
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public int getMultifileFacadeId(int index) {
+        return multifileFacadeId_.get(index);
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder setMultifileFacadeId(
+          int index, int value) {
+        ensureMultifileFacadeIdIsMutable();
+        multifileFacadeId_.set(index, value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder addMultifileFacadeId(int value) {
+        ensureMultifileFacadeIdIsMutable();
+        multifileFacadeId_.add(value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder addAllMultifileFacadeId(
+          java.lang.Iterable<? extends java.lang.Integer> values) {
+        ensureMultifileFacadeIdIsMutable();
+        org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+            values, multifileFacadeId_);
+        
+        return this;
+      }
+      /**
+       * <code>repeated int32 multifile_facade_id = 3 [packed = true];</code>
+       *
+       * <pre>
+       * For each class name listed above, index of the name of the corresponding multi-file facade class in multifile_facade_name + 1,
+       * or 0 if the class is not a multi-file part. If there's no value in this list at some index, the value is assumed to be 0.
+       * (e.g. if there are no multi-file classes in the module, this list is not going to exist at all)
+       * </pre>
+       */
+      public Builder clearMultifileFacadeId() {
+        multifileFacadeId_ = java.util.Collections.emptyList();
+        bitField0_ = (bitField0_ & ~0x00000004);
+        
+        return this;
+      }
+
+      private org.jetbrains.kotlin.protobuf.LazyStringList multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+      private void ensureMultifileFacadeNameIsMutable() {
+        if (!((bitField0_ & 0x00000008) == 0x00000008)) {
+          multifileFacadeName_ = new org.jetbrains.kotlin.protobuf.LazyStringArrayList(multifileFacadeName_);
+          bitField0_ |= 0x00000008;
+         }
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public org.jetbrains.kotlin.protobuf.ProtocolStringList
+          getMultifileFacadeNameList() {
+        return multifileFacadeName_.getUnmodifiableView();
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public int getMultifileFacadeNameCount() {
+        return multifileFacadeName_.size();
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public java.lang.String getMultifileFacadeName(int index) {
+        return multifileFacadeName_.get(index);
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public org.jetbrains.kotlin.protobuf.ByteString
+          getMultifileFacadeNameBytes(int index) {
+        return multifileFacadeName_.getByteString(index);
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder setMultifileFacadeName(
+          int index, java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.set(index, value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addMultifileFacadeName(
+          java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.add(value);
+        
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addAllMultifileFacadeName(
+          java.lang.Iterable<java.lang.String> values) {
+        ensureMultifileFacadeNameIsMutable();
+        org.jetbrains.kotlin.protobuf.AbstractMessageLite.Builder.addAll(
+            values, multifileFacadeName_);
+        
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder clearMultifileFacadeName() {
+        multifileFacadeName_ = org.jetbrains.kotlin.protobuf.LazyStringArrayList.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000008);
+        
+        return this;
+      }
+      /**
+       * <code>repeated string multifile_facade_name = 4;</code>
+       *
+       * <pre>
+       * Short names of multi-file facades, used in multifile_facade_id to store the part -&gt; facade mapping.
+       * </pre>
+       */
+      public Builder addMultifileFacadeNameBytes(
+          org.jetbrains.kotlin.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureMultifileFacadeNameIsMutable();
+        multifileFacadeName_.add(value);
+        
+        return this;
+      }
+
       // @@protoc_insertion_point(builder_scope:org.jetbrains.kotlin.serialization.jvm.PackageParts)
     }
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/vfilefinder/moduleMappingIndexes.kt

@@ -42,13 +42,18 @@ object KotlinModuleMappingIndex : FileBasedIndexExtension<String, PackageParts>(
     private val VALUE_EXTERNALIZER = object : DataExternalizer<PackageParts> {
         override fun read(input: DataInput): PackageParts? =
                 PackageParts(IOUtil.readUTF(input)).apply {
-                    IOUtil.readStringList(input).forEach(this::addPart)
+                    val shortPartNames = IOUtil.readStringList(input)
+                    val shortFacadeNames = IOUtil.readStringList(input)
+                    for ((partName, facadeName) in shortPartNames zip shortFacadeNames) {
+                        addPart(partName, if (facadeName.isNotEmpty()) facadeName else null)
+                    }
                     IOUtil.readStringList(input).forEach(this::addMetadataPart)
                 }
 
-        override fun save(out: DataOutput, value: PackageParts?) {
+        override fun save(out: DataOutput, value: PackageParts) {
-            IOUtil.writeUTF(out, value!!.packageFqName)
+            IOUtil.writeUTF(out, value.packageFqName)
             IOUtil.writeStringList(out, value.parts)
+            IOUtil.writeStringList(out, value.parts.map { value.getMultifileFacadeName(it).orEmpty() })
             IOUtil.writeStringList(out, value.metadataParts)
         }
     }
@@ -65,7 +70,7 @@ object KotlinModuleMappingIndex : FileBasedIndexExtension<String, PackageParts>(
         return FileBasedIndex.InputFilter { file -> file.extension == ModuleMapping.MAPPING_FILE_EXT }
     }
 
-    override fun getVersion(): Int = 3
+    override fun getVersion(): Int = 4
 
     override fun getIndexer(): DataIndexer<String, PackageParts, FileContent> {
         return DataIndexer<String, PackageParts, FileContent> { inputData ->