Scaladoc Overload Method Reference Fix Try 2 by bvenners · Pull Request #16 · artimahub/scala3

bvenners · 2026-01-20T05:55:44Z

@cheeseng The new tests pass, but I was unable to study the code changes today. I will do so tomorrow morning, but I would like you to have the opportunity to take a look during your day.

I had asked one of my "friends" to fix the bug more generally. Here's what the friend said:

Summary                                                                                                                           
                                                                                                                                    
  Part 1: Fixed MemberLookup.scala                                                                                                  
                                                                                                                                    
  Replaced hardcoded type matching with a generic signature-based approach:                                                         
                                                                                                                                    
  1. Added parseSignatureParams() - Parses parameter types from method signatures, handling nested brackets correctly               
    - Input: "[A](b:scala.collection.mutable.Buffer[A],c:Int)"                                                                      
    - Output: List("scala.collection.mutable.Buffer", "Int")                                                                        
  2. Added extractSimpleTypeName() - Extracts simple type name from qualified types                                                 
    - Input: "scala.collection.mutable.Buffer[A]" → Output: "Buffer"                                                                
  3. Rewrote matchesParameterTypes() - Compares ALL parameter types in order (not just checking if "any contains")                  
  4. Removed the hardcoded extractParamTypeFromSignature() that only matched 10 collection types                                    
                                                                                                                                    
  Part 2: Added Tests to MemberLookupTests.scala                                                                                    
                                                                                                                                    
  - Added funOverload() helper to find specific overloads by parameter types                                                        
  - Added testOverloadedMethodLookup() with tests for:                                                                              
    - Collection types (Buffer, Map, Set, Seq, Iterator, Iterable, List, Properties)                                                
    - Primitive types (Int)                                                                                                         
    - Custom user-defined types (CustomTypeA, CustomTypeB)                                                                          
    - Multiple parameters in order (Buffer+Set vs Set+Buffer)                                                                       
    - Fallback behavior for queries without signatures                                                                              
                                                                                                                                    
  Part 3: Added Tests to QueryParserTests.scala                                                                                     
                                                                                                                                    
  - Nested generics: foo[A](x:Map[String,List[A]])*                                                                                 
  - Multiple parameters: bar(a:Int,b:String)*                                                                                       
  - Empty parameters: noArgs()*                                                                                                     
  - Complex nesting: complex[A](x:Map[String,Map[Int,List[A]]])*                                                                    
  - Custom types: process(x:tests.CustomType)*                                                                                      
                                                                                                                                    
  Part 4: Expanded overloadedMethods.scala                                                                                          
                                                                                                                                    
  Added new test classes:                                                                                                           
  - CustomTypeA, CustomTypeB - Custom types for testing                                                                             
  - CustomTypeOverloads - Methods overloaded with custom types                                                                      
  - MultiParamOverloads - Methods with multiple parameters in different orders                                                      
  - CustomTypeLinks, MultiParamLinks - Documentation links to test resolution

This is how you can run the new tests:

  Run all Scaladoc tests:                                                                                                           
  sbt scaladoc/test                                                                                                                 
                                                                                                                                    
  Run specific test classes:                                                                                                        
  # Query parser tests                                                                                                              
  sbt "scaladoc/testOnly *QueryParserTests*"                                                                                        
                                                                                                                                    
  # Member lookup tests (includes overload resolution tests)                                                                        
  sbt "scaladoc/testOnly *MemberLookupTests*"                                                                                       
                                                                                                                                    
  Run both test classes together:                                                                                                   
  sbt "scaladoc/testOnly *QueryParserTests* *MemberLookupTests*"

…ttps://www.scala-lang.org/api/3.7.4/scala/collection/convert/AsJavaExtensions$BufferHasAsJava.html , where the asJava method it is linked to asJava method that takes Map, which is wrong, it should link to asJava that takes Buffer.

cheeseng · 2026-01-20T09:48:03Z

Hmm, unfortunately when I run 'sbt clean test' now the following are failing:

[error] Failed: Total 537, Failed 5, Errors 0, Passed 527, Skipped 5, Ignored 6
[error] Failed tests:
[error] 	dotty.tools.dotc.FromTastyTests
[error] 	dotty.tools.dotc.IdempotencyTests
[error] 	dotty.tools.debug.DebugTests
[error] 	dotty.tools.dotc.CompilationTests
[error] (scala3-compiler-nonbootstrapped / Test / testOnly) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 1835 s (0:30:35.0), completed 20 Jan 2026, 17:45:31

I'll try to look into why they are failing.

cheeseng · 2026-01-23T15:08:45Z

Superseded by #18 .

@OverRide

Fix scala#22628 Super call like `super.m()` were emitted with `invokespecial` where owner = `fun.symbol.owner` (the method declaration owner). However, that is wrong for some inherited Java members: the declaration owner can be less accessible than the direct superclass at the Scala call site. In that case it causes `IllegalAccessError` at runtime. This aligns with the normal call behavior, see: scala@fa42b81 **example** In the example below, `fun.symbol.owner` for `super.close()` is `InnerServerCallBase` (where `close` is declared) that is not accessible from `mycode` package. ```scala // mylib/InnerServerCallBase.java (package-private) package mylib; abstract class InnerServerCallBase implements ServerCall { @OverRide public void close() { System.out.println("InnerServerCallBase.close"); } } // mylib/PublicServerCallBase.java package mylib; public abstract class PublicServerCallBase extends InnerServerCallBase {} // mycode/MyServerCall.scala package mycode class MyServerCall extends mylib.PublicServerCallBase: override def close(): Unit = println("MyServerCall.close") super.close() ``` As a result, Scala3 emits the following Java bytecode where `invokespecial` on non-accessible class method. And it causes `IllegalAccessError` at runtime. Scala 3 (before): ```java 0: getstatic #18 // Field scala/Predef$.MODULE$:Lscala/Predef$; 3: ldc #20 // String MyServerCall.close 5: invokevirtual #24 // Method scala/Predef$.println:(Ljava/lang/Object;)V 8: aload_0 9: invokespecial #28 // Method mylib/InnerServerCallBase.close:()V 12: return ``` We should generate `invokespecial` on the call-site qualifier type instead, like Scala 2.13 emits. Scala 2.13 ``` 0: getstatic #16 // Field scala/Predef$.MODULE$:Lscala/Predef$; 3: ldc #18 // String MyServerCall.close 5: invokevirtual #22 // Method scala/Predef$.println:(Ljava/lang/Object;)V 8: aload_0 9: invokespecial #24 // Method mylib/PublicServerCallBase.close:()V 12: return ``` This commit fixes the issue by using call-site qualifier type for invokespecial on super call.

@OverRide

Fix scala#22628 scala#24084 as well ? Super call like `super.m()` were emitted with `invokespecial` where owner = `fun.symbol.owner` (the method declaration owner). However, that is wrong for some inherited Java members: the declaration owner can be less accessible than the direct superclass at the Scala call site. In that case it causes `IllegalAccessError` at runtime. This aligns with the normal call behavior, see: scala@fa42b81 **example** In the example below, `fun.symbol.owner` for `super.close()` is `InnerServerCallBase` (where `close` is declared) that is not accessible from `mycode` package. ```scala // mylib/InnerServerCallBase.java (package-private) package mylib; abstract class InnerServerCallBase implements ServerCall { @OverRide public void close() { System.out.println("InnerServerCallBase.close"); } } // mylib/PublicServerCallBase.java package mylib; public abstract class PublicServerCallBase extends InnerServerCallBase {} // mycode/MyServerCall.scala package mycode class MyServerCall extends mylib.PublicServerCallBase: override def close(): Unit = println("MyServerCall.close") super.close() ``` As a result, Scala3 emits the following Java bytecode where `invokespecial` on non-accessible class method. And it causes `IllegalAccessError` at runtime. Scala 3 (before): ```java 0: getstatic #18 // Field scala/Predef$.MODULE$:Lscala/Predef$; 3: ldc #20 // String MyServerCall.close 5: invokevirtual #24 // Method scala/Predef$.println:(Ljava/lang/Object;)V 8: aload_0 9: invokespecial #28 // Method mylib/InnerServerCallBase.close:()V 12: return ``` We should generate `invokespecial` on the call-site qualifier type instead, like Scala 2.13 emits. Scala 2.13 ``` 0: getstatic #16 // Field scala/Predef$.MODULE$:Lscala/Predef$; 3: ldc #18 // String MyServerCall.close 5: invokevirtual #22 // Method scala/Predef$.println:(Ljava/lang/Object;)V 8: aload_0 9: invokespecial #24 // Method mylib/PublicServerCallBase.close:()V 12: return ``` This commit fixes the issue by using call-site qualifier type for invokespecial on super call. --- Huge thanks to @migesok for creating a reproducible example 🙌 https://github.com/migesok/scala3-bug-super-IllegalAccessError

cheeseng and others added 3 commits January 19, 2026 16:35

Merge branch 'main' into fix-scaladoc-reference-overload-methods

9c0b56e

Attempt at fixing the link to overloaded method bug more generally.

51f3572

bvenners requested a review from cheeseng January 20, 2026 05:55

bvenners self-assigned this Jan 20, 2026

cheeseng closed this Jan 23, 2026

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Scaladoc Overload Method Reference Fix Try 2 - #16

Scaladoc Overload Method Reference Fix Try 2#16
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