Emit additional occurrences for synthetic Scala symbols

lsif-java/src/main/scala/com/sourcegraph/lsif_java/SemanticdbPrinters.scala

@@ -17,7 +17,9 @@ object SemanticdbPrinters {
       comments: CommentSyntax = CommentSyntax.default
   ): String = {
     val occurrencesByLine = LsifTextDocument
-      .sortedSymbolOccurrences(doc)
+      .sortedSymbolOccurrences(
+        LsifTextDocument.manifestOccurrencesForSyntheticSymbols(doc)
+      )
       .asScala
       .groupBy(_.getRange.getStartLine)
     val out = new StringBuilder()

lsif-semanticdb/src/main/java/com/sourcegraph/lsif_semanticdb/LsifTextDocument.java

@@ -1,11 +1,10 @@
 package com.sourcegraph.lsif_semanticdb;
 
 import com.sourcegraph.semanticdb_javac.Semanticdb;
+import com.sourcegraph.semanticdb_javac.SemanticdbSymbols;
+
 import java.nio.file.Path;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 /** Wrapper around a SemanticDB TextDocument with LSIF-related utilities. */
 public class LsifTextDocument {
@@ -74,9 +73,75 @@ void visitIdTree(Semanticdb.IdTree tree) {
   }
 
   private void setSemanticdb(Semanticdb.TextDocument semanticdb) {
-    this.semanticdb = semanticdb;
+    this.semanticdb = manifestOccurrencesForSyntheticSymbols(semanticdb);
     for (Semanticdb.SymbolInformation info : semanticdb.getSymbolsList()) {
       symbols.put(info.getSymbol(), info);
     }
   }
+
+  public static Semanticdb.TextDocument manifestOccurrencesForSyntheticSymbols(
+      Semanticdb.TextDocument semanticdb) {
+    if (semanticdb.getLanguage() != Semanticdb.Language.SCALA) {
+      // It's only semanticdb-scalac that emits SymbolInformation for symbols that have no
+      // definition occurrences.
+      return semanticdb;
+    }
+    Semanticdb.TextDocument.Builder builder = Semanticdb.TextDocument.newBuilder(semanticdb);
+    HashMap<String, Semanticdb.SymbolOccurrence> definitionOccurrences = new HashMap<>();
+    for (Semanticdb.SymbolOccurrence occ : semanticdb.getOccurrencesList()) {
+      if (occ.getRole() == Semanticdb.SymbolOccurrence.Role.DEFINITION) {
+        definitionOccurrences.put(occ.getSymbol(), occ);
+      }
+    }
+    for (Semanticdb.SymbolInformation info : semanticdb.getSymbolsList()) {
+      Semanticdb.SymbolOccurrence definition = definitionOccurrences.get(info.getSymbol());
+      if (definition != null) {
+        continue;
+      }
+      for (String alternativeSymbol : alternativeSymbols(info)) {
+        Semanticdb.SymbolOccurrence alternativeDefinition =
+            definitionOccurrences.get(alternativeSymbol);
+        if (alternativeDefinition != null) {
+          builder.addOccurrences(
+              Semanticdb.SymbolOccurrence.newBuilder(alternativeDefinition)
+                  .setSymbol(info.getSymbol()));
+          break;
+        }
+      }
+    }
+    return builder.build();
+  }
+
+  public static final Set<String> syntheticCaseClassMethodNames =
+      new HashSet<>(Arrays.asList("copy", "productElement", "productElementName"));
+  public static final Set<String> syntheticCompanionObjectNames =
+      new HashSet<>(Arrays.asList("apply", "copy"));
+
+  public static List<String> alternativeSymbols(Semanticdb.SymbolInformation info) {
+    ArrayList<String> alternatives = new ArrayList<>();
+    SymbolDescriptor sym = SymbolDescriptor.parseFromSymbol(info.getSymbol());
+    switch (sym.descriptor.kind) {
+      case Method:
+        if (sym.descriptor.name.endsWith("_=")) {
+          String newName = sym.descriptor.name.substring(0, sym.descriptor.name.length() - 2);
+          alternatives.add(SemanticdbSymbols.global(sym.owner, sym.descriptor.withName(newName)));
+        } else if (syntheticCaseClassMethodNames.contains(sym.descriptor.name)) {
+          alternatives.add(sym.owner);
+        } else if (syntheticCompanionObjectNames.contains(sym.descriptor.name)) {
+          alternatives.add(sym.owner);
+          SymbolDescriptor owner = SymbolDescriptor.parseFromSymbol(sym.owner);
+          alternatives.add(
+              SemanticdbSymbols.global(
+                  owner.owner, owner.descriptor.withKind(SemanticdbSymbols.Descriptor.Kind.Type)));
+        }
+        break;
+      case Term:
+        alternatives.add(
+            SemanticdbSymbols.global(
+                sym.owner, sym.descriptor.withKind(SemanticdbSymbols.Descriptor.Kind.Type)));
+        break;
+      default:
+    }
+    return alternatives;
+  }
 }

semanticdb-java/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbSymbols.java

@@ -79,6 +79,14 @@ public Descriptor(Kind kind, String name, String disambiguator) {
       this.disambiguator = disambiguator;
     }
 
+    public Descriptor withName(String newName) {
+      return new Descriptor(kind, newName, disambiguator);
+    }
+
+    public Descriptor withKind(Kind newKind) {
+      return new Descriptor(newKind, name, disambiguator);
+    }
+
     public static Descriptor local(String name) {
       return new Descriptor(Kind.Local, name);
     }

tests/minimized-scala/src/main/scala/minimized/Issue396.scala

@@ -0,0 +1,9 @@
+package minimized
+
+case class Issue396(a: Int)
+object Issue396App {
+  println(Issue396)
+  Issue396.apply(42).copy(a = 41)
+  Issue396.apply(42).productElement(0)
+  Issue396.apply(42).productElementName(0)
+}

tests/minimized-scala/src/main/scala/minimized/Issue397.scala

@@ -0,0 +1,6 @@
+package minimized
+
+class Issue397 {
+  var blah = Set("abc")
+  blah = Set.empty[String]
+}

tests/snapshots/src/main/generated/BaseByteRenderer.scala

@@ -23,6 +23,7 @@ import upickle.core.{ArrVisitor, ObjVisitor}
   */
 class BaseByteRenderer[T <: upickle.core.ByteOps.Output]
 //    ^^^^^^^^^^^^^^^^ definition ujson/BaseByteRenderer# class BaseByteRenderer[T <: Output]
+//    ^^^^^^^^^^^^^^^^ definition ujson/BaseByteRenderer. object BaseByteRenderer
 //                     ^ definition ujson/BaseByteRenderer#[T] T <: Output
 //                          ^^^^^^^ reference upickle/
 //                                  ^^^^ reference upickle/core/
@@ -65,11 +66,13 @@ class BaseByteRenderer[T <: upickle.core.ByteOps.Output]
 
   private[this] var depth: Int = 0
 //                  ^^^^^ definition ujson/BaseByteRenderer#depth(). private[this] var depth: Int
+//                  ^^^^^ definition ujson/BaseByteRenderer#`depth_=`(). private[this] var depth_=(x$1: Int): Unit
 //                         ^^^ reference scala/Int#
 
 
   private[this] var commaBuffered = false
 //                  ^^^^^^^^^^^^^ definition ujson/BaseByteRenderer#commaBuffered(). private[this] var commaBuffered: Boolean
+//                  ^^^^^^^^^^^^^ definition ujson/BaseByteRenderer#`commaBuffered_=`(). private[this] var commaBuffered_=(x$1: Boolean): Unit
 
   def flushBuffer() = {
 //    ^^^^^^^^^^^ definition ujson/BaseByteRenderer#flushBuffer(). def flushBuffer(): Unit

tests/snapshots/src/main/generated/BaseCharRenderer.scala

@@ -23,6 +23,7 @@ import upickle.core.{ArrVisitor, ObjVisitor}
   */
 class BaseCharRenderer[T <: upickle.core.CharOps.Output]
 //    ^^^^^^^^^^^^^^^^ definition ujson/BaseCharRenderer# class BaseCharRenderer[T <: Output]
+//    ^^^^^^^^^^^^^^^^ definition ujson/BaseCharRenderer. object BaseCharRenderer
 //                     ^ definition ujson/BaseCharRenderer#[T] T <: Output
 //                          ^^^^^^^ reference upickle/
 //                                  ^^^^ reference upickle/core/
@@ -65,11 +66,13 @@ class BaseCharRenderer[T <: upickle.core.CharOps.Output]
 
   private[this] var depth: Int = 0
 //                  ^^^^^ definition ujson/BaseCharRenderer#depth(). private[this] var depth: Int
+//                  ^^^^^ definition ujson/BaseCharRenderer#`depth_=`(). private[this] var depth_=(x$1: Int): Unit
 //                         ^^^ reference scala/Int#
 
 
   private[this] var commaBuffered = false
 //                  ^^^^^^^^^^^^^ definition ujson/BaseCharRenderer#commaBuffered(). private[this] var commaBuffered: Boolean
+//                  ^^^^^^^^^^^^^ definition ujson/BaseCharRenderer#`commaBuffered_=`(). private[this] var commaBuffered_=(x$1: Boolean): Unit
 
   def flushBuffer() = {
 //    ^^^^^^^^^^^ definition ujson/BaseCharRenderer#flushBuffer(). def flushBuffer(): Unit

tests/snapshots/src/main/generated/minimized/Issue396.scala

@@ -0,0 +1,32 @@
+package minimized
+//      ^^^^^^^^^ definition minimized/
+
+case class Issue396(a: Int)
+//         ^^^^^^^^ definition minimized/Issue396# case class Issue396(a: Int)
+//         ^^^^^^^^ definition minimized/Issue396#copy(). def copy(a: Int): Issue396
+//         ^^^^^^^^ definition minimized/Issue396#productElement(). def productElement(x$1: Int): Any
+//         ^^^^^^^^ definition minimized/Issue396. object Issue396
+//         ^^^^^^^^ definition minimized/Issue396.apply(). def apply(a: Int): Issue396
+//         ^^^^^^^^ definition minimized/Issue396#productElementName(). def productElementName(x$1: Int): String
+//                  definition minimized/Issue396#`<init>`(). def this(a: Int)
+//                  ^ definition minimized/Issue396#a. val a: Int
+//                     ^^^ reference scala/Int#
+object Issue396App {
+//     ^^^^^^^^^^^ definition minimized/Issue396App. object Issue396App
+  println(Issue396)
+//^^^^^^^ reference scala/Predef.println(+1).
+//        ^^^^^^^^ reference minimized/Issue396.
+  Issue396.apply(42).copy(a = 41)
+//^^^^^^^^ reference minimized/Issue396.
+//         ^^^^^ reference minimized/Issue396.apply().
+//                   ^^^^ reference minimized/Issue396#copy().
+//                        ^ reference minimized/Issue396#copy().(a)
+  Issue396.apply(42).productElement(0)
+//^^^^^^^^ reference minimized/Issue396.
+//         ^^^^^ reference minimized/Issue396.apply().
+//                   ^^^^^^^^^^^^^^ reference minimized/Issue396#productElement().
+  Issue396.apply(42).productElementName(0)
+//^^^^^^^^ reference minimized/Issue396.
+//         ^^^^^ reference minimized/Issue396.apply().
+//                   ^^^^^^^^^^^^^^^^^^ reference minimized/Issue396#productElementName().
+}

tests/snapshots/src/main/generated/minimized/Issue397.scala

@@ -0,0 +1,17 @@
+package minimized
+//      ^^^^^^^^^ definition minimized/
+
+class Issue397 {
+//    ^^^^^^^^ definition minimized/Issue397# class Issue397
+//              definition minimized/Issue397#`<init>`(). def this()
+  var blah = Set("abc")
+//    ^^^^ definition minimized/Issue397#blah(). var blah: Set[String]
+//    ^^^^ definition minimized/Issue397#`blah_=`(). var blah_=(x$1: Set[String]): Unit
+//           ^^^ reference scala/Predef.Set.
+//               reference scala/collection/IterableFactory#apply().
+  blah = Set.empty[String]
+//^^^^ reference minimized/Issue397#`blah_=`().
+//       ^^^ reference scala/Predef.Set.
+//           ^^^^^ reference scala/collection/immutable/Set.empty().
+//                 ^^^^^^ reference scala/Predef.String#
+}

tests/snapshots/src/main/generated/minimized/MinimizedScalaSignatures.scala

@@ -6,6 +6,11 @@ package minimized
 
 case class MinimizedCaseClass(value: String) {
 //         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass# case class MinimizedCaseClass(value: String)
+//         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass.apply(). def apply(value: String): MinimizedCaseClass
+//         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass#productElement(). def productElement(x$1: Int): Any
+//         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass. object MinimizedCaseClass
+//         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass#productElementName(). def productElementName(x$1: Int): String
+//         ^^^^^^^^^^^^^^^^^^ definition minimized/MinimizedCaseClass#copy(). def copy(value: String): MinimizedCaseClass
 //                            definition minimized/MinimizedCaseClass#`<init>`(). def this(value: String)
 //                            ^^^^^ definition minimized/MinimizedCaseClass#value. val value: String
 //                                   ^^^^^^ reference scala/Predef.String#

tests/snapshots/src/main/generated/ujson/AstTransformer.scala

@@ -119,6 +119,7 @@ trait AstTransformer[I] extends Transformer[I] with JsVisitor[I, I]{
 
     private[this] var key: String = null
 //                    ^^^ definition ujson/AstTransformer#AstObjVisitor#key(). private[this] var key: String
+//                    ^^^ definition ujson/AstTransformer#AstObjVisitor#`key_=`(). private[this] var key_=(x$1: String): Unit
 //                         ^^^^^^ reference scala/Predef.String#
     private[this] val vs = factory.newBuilder
 //                    ^^ definition ujson/AstTransformer#AstObjVisitor#vs. private[this] val vs: Builder[(String, I), T]

tests/snapshots/src/main/generated/ujson/Exceptions.scala

@@ -8,6 +8,11 @@ sealed trait ParsingFailedException extends Exception
 
 case class ParseException(clue: String, index: Int)
 //         ^^^^^^^^^^^^^^ definition ujson/ParseException# case class ParseException(clue: String, index: Int) extends Exception with ParsingFailedException
+//         ^^^^^^^^^^^^^^ definition ujson/ParseException#productElementName(). def productElementName(x$1: Int): String
+//         ^^^^^^^^^^^^^^ definition ujson/ParseException.apply(). def apply(clue: String, index: Int): ParseException
+//         ^^^^^^^^^^^^^^ definition ujson/ParseException. object ParseException
+//         ^^^^^^^^^^^^^^ definition ujson/ParseException#copy(). def copy(clue: String, index: Int): ParseException
+//         ^^^^^^^^^^^^^^ definition ujson/ParseException#productElement(). def productElement(x$1: Int): Any
 //                        definition ujson/ParseException#`<init>`(). def this(clue: String, index: Int)
 //                        ^^^^ definition ujson/ParseException#clue. val clue: String
 //                              ^^^^^^ reference scala/Predef.String#
@@ -24,6 +29,11 @@ case class ParseException(clue: String, index: Int)
 
 case class IncompleteParseException(msg: String)
 //         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException# case class IncompleteParseException(msg: String) extends Exception with ParsingFailedException
+//         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException#productElement(). def productElement(x$1: Int): Any
+//         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException.apply(). def apply(msg: String): IncompleteParseException
+//         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException#copy(). def copy(msg: String): IncompleteParseException
+//         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException#productElementName(). def productElementName(x$1: Int): String
+//         ^^^^^^^^^^^^^^^^^^^^^^^^ definition ujson/IncompleteParseException. object IncompleteParseException
 //                                  definition ujson/IncompleteParseException#`<init>`(). def this(msg: String)
 //                                  ^^^ definition ujson/IncompleteParseException#msg. val msg: String
 //                                       ^^^^^^ reference scala/Predef.String#