Equivalent .class fields should share the same symbol

[B. Blaser]

On 16 April 2018 at 19:40, Jan Lahoda <jan.lahoda at oracle.com> wrote:
> On 16.4.2018 19:31, B. Blaser wrote:
>>
>> Hi Jan,
>>
>> On 16 April 2018 at 17:02, Jan Lahoda <jan.lahoda at oracle.com> wrote:
>>>
>>> Hi Bernard,
>>>
>>> [...]
>>>
>>> -should there be a method in Symtab managing the map? Something like:
>>> Symtab.getClassField(TypeSymbol tsym) {/*create the VarSymbol is
>>> needed*/}
>>
>>
>> I'll take a look if you think it's worth adding a method for this.
>
>
> I think it would be nicer than maintaining the map from another class, if
> possible/doable.
>
> Thanks,
>     Jan

Here it is, javac tests are OK.
Cheers,
Bernard

diff -r 8c85a1855e10
src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java
Fri Apr 13 11:14:49 2018 -0700
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java
Mon Apr 16 23:33:02 2018 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -51,6 +51,7 @@
 import com.sun.tools.javac.code.Type.JCVoidType;
 import com.sun.tools.javac.code.Type.MethodType;
 import com.sun.tools.javac.code.Type.UnknownType;
+import com.sun.tools.javac.code.Types.UniqueType;
 import com.sun.tools.javac.comp.Modules;
 import com.sun.tools.javac.util.Assert;
 import com.sun.tools.javac.util.Context;
@@ -247,6 +248,26 @@
      */
     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();

+    private final Map<Types.UniqueType, VarSymbol> classFields = new
HashMap<>();
+
+    public VarSymbol getClassField(Type type, Types types) {
+        return classFields.computeIfAbsent(
+            new UniqueType(type, types), k -> {
+                Type arg = null;
+                if (type.getTag() == ARRAY || type.getTag() == CLASS)
+                    arg = types.erasure(type);
+                else if (type.isPrimitiveOrVoid())
+                    arg = types.boxedClass(type).type;
+                else
+                    throw new AssertionError(type);
+
+                Type t = new ClassType(
+                    classType.getEnclosingType(), List.of(arg),
classType.tsym);
+                return new VarSymbol(
+                    STATIC | PUBLIC | FINAL, names._class, t, type.tsym);
+            });
+    }
+
     public void initType(Type type, ClassSymbol c) {
         type.tsym = c;
         typeOfTag[type.getTag().ordinal()] = type;
diff -r 8c85a1855e10
src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
Fri Apr 13 11:14:49 2018 -0700
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
Mon Apr 16 23:33:02 2018 +0200
@@ -3731,11 +3731,7 @@
                 } else if (name == names._class) {
                     // In this case, we have already made sure in
                     // visitSelect that qualifier expression is a type.
-                    Type t = syms.classType;
-                    List<Type> typeargs = List.of(types.erasure(site));
-                    t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
-                    return new VarSymbol(
-                        STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
+                    return syms.getClassField(site, types);
                 } else {
                     // We are seeing a plain identifier as selector.
                     Symbol sym = rs.findIdentInType(env, site, name,
resultInfo.pkind);
@@ -3773,11 +3769,7 @@
                 if (name == names._class) {
                     // In this case, we have already made sure in Select that
                     // qualifier expression is a type.
-                    Type t = syms.classType;
-                    Type arg = types.boxedClass(site).type;
-                    t = new ClassType(t.getEnclosingType(),
List.of(arg), t.tsym);
-                    return new VarSymbol(
-                        STATIC | PUBLIC | FINAL, names._class, t, site.tsym);
+                    return syms.getClassField(site, types);
                 } else {
                     log.error(pos, Errors.CantDeref(site));
                     return syms.errSymbol;
diff -r 8c85a1855e10
test/langtools/tools/javac/lambda/deduplication/Deduplication.java
--- a/test/langtools/tools/javac/lambda/deduplication/Deduplication.java
Fri Apr 13 11:14:49 2018 -0700
+++ b/test/langtools/tools/javac/lambda/deduplication/Deduplication.java
Mon Apr 16 23:33:02 2018 +0200
@@ -38,6 +38,31 @@
                 (Runnable) () -> { ( (Runnable) () -> {} ).run(); }
         );

+        group(
+                (Runnable) () -> { Deduplication.class.toString(); },
+                (Runnable) () -> { Deduplication.class.toString(); }
+        );
+
+        group(
+                (Runnable) () -> { Integer[].class.toString(); },
+                (Runnable) () -> { Integer[].class.toString(); }
+        );
+
+        group(
+                (Runnable) () -> { char.class.toString(); },
+                (Runnable) () -> { char.class.toString(); }
+        );
+
+        group(
+                (Runnable) () -> { Void.class.toString(); },
+                (Runnable) () -> { Void.class.toString(); }
+        );
+
+        group(
+                (Runnable) () -> { void.class.toString(); },
+                (Runnable) () -> { void.class.toString(); }
+        );
+
         group((Function<String, Integer>) x -> x.hashCode());
         group((Function<Object, Integer>) x -> x.hashCode());