From 3aeb66885bacbc175fc51c93e303173d2a654a74 Mon Sep 17 00:00:00 2001
From: Robert Muir <rmuir@apache.org>
Date: Tue, 10 May 2016 05:44:16 -0400
Subject: [PATCH] painless: use better typing for dynamic method calls

---
 .../org/elasticsearch/painless/WriterExternal.java    | 11 +++++++----
 .../painless/WhenThingsGoWrongTests.java              |  3 ++-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterExternal.java b/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterExternal.java
index ab05e1b6e56..1ead39c467b 100644
--- a/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterExternal.java
+++ b/modules/lang-painless/src/main/java/org/elasticsearch/painless/WriterExternal.java
@@ -20,6 +20,7 @@
 package org.elasticsearch.painless;
 
 import org.antlr.v4.runtime.ParserRuleContext;
+import org.elasticsearch.painless.Definition.Cast;
 import org.elasticsearch.painless.Definition.Constructor;
 import org.elasticsearch.painless.Definition.Field;
 import org.elasticsearch.painless.Definition.Method;
@@ -714,14 +715,16 @@ class WriterExternal {
         // first parameter is the receiver, we never know its type: always Object
         signature.append(WriterConstants.OBJECT_TYPE.getDescriptor());
 
-        // TODO: remove our explicit conversions and feed more type information for args/return value,
-        // it can avoid some unnecessary boxing etc.
         for (int i = 0; i < arguments.size(); i++) {
-            signature.append(WriterConstants.OBJECT_TYPE.getDescriptor());
+            ExpressionMetadata arg = metadata.getExpressionMetadata(arguments.get(i));
+            // disable any implicit casts/conversion for arguments, let invokeDynamic take care
+            arg.to = arg.from;
+            arg.cast = new Cast(arg.from, arg.from);
+            signature.append(arg.from.type.getDescriptor());
             writer.visit(arguments.get(i));
         }
         signature.append(')');
-        // return value
+        // return value: currently always Object. making this better may be tricky...
         signature.append(WriterConstants.OBJECT_TYPE.getDescriptor());
         execute.visitInvokeDynamicInsn((String)sourceenmd.target, signature.toString(), 
                                        WriterConstants.DEF_BOOTSTRAP_HANDLE, new Object[] { DynamicCallSite.METHOD_CALL });
diff --git a/modules/lang-painless/src/test/java/org/elasticsearch/painless/WhenThingsGoWrongTests.java b/modules/lang-painless/src/test/java/org/elasticsearch/painless/WhenThingsGoWrongTests.java
index 3f79ae1974b..975e2301877 100644
--- a/modules/lang-painless/src/test/java/org/elasticsearch/painless/WhenThingsGoWrongTests.java
+++ b/modules/lang-painless/src/test/java/org/elasticsearch/painless/WhenThingsGoWrongTests.java
@@ -19,6 +19,7 @@
 
 package org.elasticsearch.painless;
 
+import java.lang.invoke.WrongMethodTypeException;
 import java.util.Arrays;
 import java.util.Collections;
 
@@ -140,7 +141,7 @@ public class WhenThingsGoWrongTests extends ScriptTestCase {
     }
     
     public void testDynamicWrongArgs() {
-        expectThrows(ClassCastException.class, () -> {
+        expectThrows(WrongMethodTypeException.class, () -> {
             exec("def x = new ArrayList(); return x.get('bogus');");
         });
     }