Equivalent .class fields should share the same symbol

[B. Blaser]

Hi Rémi,

On 15 April 2018 at 14:31, Remi Forax <forax at univ-mlv.fr> wrote:
> Hi,
> You can use Map.computeIfAbsent instead of putIfAbsent to avoid to create the Symbol before checking if one exist or not.
>
> Also you using _class for several purpose, the Map should be named classes and the local variable classSymbol or something like that.
>
> cheers,
> Rémi

Thanks for your feedback, nice suggestions.
Here is the updated version.

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
Sun Apr 15 17:15:36 2018 +0200
@@ -247,6 +247,8 @@
      */
     private final Map<Name, ModuleSymbol> modules = new LinkedHashMap<>();

+    public final Map<Types.UniqueType, VarSymbol> classFields = new
HashMap<>();
+
     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
Sun Apr 15 17:15:36 2018 +0200
@@ -3731,11 +3731,14 @@
                 } 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.classFields.computeIfAbsent(
+                        new Types.UniqueType(site, types), k -> {
+                            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);
+                        });
                 } else {
                     // We are seeing a plain identifier as selector.
                     Symbol sym = rs.findIdentInType(env, site, name,
resultInfo.pkind);
@@ -3773,11 +3776,14 @@
                 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.classFields.computeIfAbsent(
+                        new Types.UniqueType(site, types), k -> {
+                            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);
+                         });
                 } 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
Sun Apr 15 17:15:36 2018 +0200
@@ -38,6 +38,21 @@
                 (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((Function<String, Integer>) x -> x.hashCode());
         group((Function<Object, Integer>) x -> x.hashCode());