8037546: javac -parameters does not emit parameter names for lambda expressions
Summary: MethodParameters attribute is missing for synthetic methods encoding lambda expressions.
Reviewed-by: rfield, mcimadamore
Contributed-by: srikanth.adayapalam@oracle.com
--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java Tue Jan 13 10:17:25 2015 +0100
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java Tue Jan 13 10:25:24 2015 +0100
@@ -263,7 +263,7 @@
@Override
public void visitLambda(JCLambda tree) {
LambdaTranslationContext localContext = (LambdaTranslationContext)context;
- MethodSymbol sym = (MethodSymbol)localContext.translatedSym;
+ MethodSymbol sym = localContext.translatedSym;
MethodType lambdaType = (MethodType) sym.type;
{
@@ -1755,7 +1755,7 @@
Map<LambdaSymbolKind, Map<Symbol, Symbol>> translatedSymbols;
/** the synthetic symbol for the method hoisting the translated lambda */
- Symbol translatedSym;
+ MethodSymbol translatedSym;
List<JCVariableDecl> syntheticParams;
@@ -1997,6 +1997,7 @@
//compute synthetic params
ListBuffer<JCVariableDecl> params = new ListBuffer<>();
+ ListBuffer<VarSymbol> parameterSymbols = new ListBuffer<>();
// The signature of the method is augmented with the following
// synthetic parameters:
@@ -2005,19 +2006,16 @@
// 2) enclosing locals captured by the lambda expression
for (Symbol thisSym : getSymbolMap(CAPTURED_VAR).values()) {
params.append(make.VarDef((VarSymbol) thisSym, null));
- }
- if (methodReferenceReceiver != null) {
- params.append(make.VarDef(
- make.Modifiers(PARAMETER|FINAL),
- names.fromString("$rcvr$"),
- make.Type(methodReferenceReceiver.type),
- null));
+ parameterSymbols.append((VarSymbol) thisSym);
}
for (Symbol thisSym : getSymbolMap(PARAM).values()) {
params.append(make.VarDef((VarSymbol) thisSym, null));
+ parameterSymbols.append((VarSymbol) thisSym);
}
syntheticParams = params.toList();
+ translatedSym.params = parameterSymbols.toList();
+
// Compute and set the lambda name
translatedSym.name = isSerializable()
? serializedLambdaName()
--- a/langtools/test/tools/javac/MethodParameters/ClassFileVisitor.java Tue Jan 13 10:17:25 2015 +0100
+++ b/langtools/test/tools/javac/MethodParameters/ClassFileVisitor.java Tue Jan 13 10:25:24 2015 +0100
@@ -147,6 +147,7 @@
public int mAttrs;
public int mNumParams;
public boolean mSynthetic;
+ public boolean mIsLambda;
public boolean mIsConstructor;
public boolean mIsClinit;
public boolean mIsBridge;
@@ -165,6 +166,7 @@
mIsClinit = mName.equals("<clinit>");
prefix = cname + "." + mName + "() - ";
mIsBridge = method.access_flags.is(AccessFlags.ACC_BRIDGE);
+ mIsLambda = mSynthetic && mName.startsWith("lambda$");
if (mIsClinit) {
sb = new StringBuilder(); // Discard output
@@ -225,7 +227,7 @@
// IMPL: Whether MethodParameters attributes will be generated
// for some synthetics is unresolved. For now, assume no.
- if (mSynthetic) {
+ if (mSynthetic && !mIsLambda) {
warn(prefix + "synthetic has MethodParameter attribute");
}
@@ -349,10 +351,12 @@
} else if (isEnum && mNumParams == 1 && index == 0 && mName.equals("valueOf")) {
expect = "name";
allowMandated = true;
- } else if (mIsBridge) {
+ } else if (mIsBridge || mIsLambda) {
allowSynthetic = true;
/* you can't expect an special name for bridges' parameters.
- * The name of the original parameters are now copied.
+ * The name of the original parameters are now copied. Likewise
+ * for a method encoding the lambda expression, names are derived
+ * from source lambda's parameters and captured enclosing locals.
*/
expect = null;
}
--- a/langtools/test/tools/javac/MethodParameters/LambdaTest.java Tue Jan 13 10:17:25 2015 +0100
+++ b/langtools/test/tools/javac/MethodParameters/LambdaTest.java Tue Jan 13 10:25:24 2015 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2015 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
@@ -23,7 +23,7 @@
/*
* @test
- * @bug 8006582
+ * @bug 8006582 8037546
* @summary javac should generate method parameters correctly.
* @build Tester
* @compile -parameters LambdaTest.java
@@ -31,8 +31,8 @@
*/
/**
- * Parameter names are not recorded for lambdas. This test verifies
- * that there are no MethodParameters attribute for lambdas.
+ * Post https://bugs.openjdk.java.net/browse/JDK-8037546, this test verifies
+ * that MethodParameters attribute for lambdas are emitted properly.
*/
class LambdaTest {
--- a/langtools/test/tools/javac/MethodParameters/LambdaTest.out Tue Jan 13 10:17:25 2015 +0100
+++ b/langtools/test/tools/javac/MethodParameters/LambdaTest.out Tue Jan 13 10:25:24 2015 +0100
@@ -1,7 +1,7 @@
class LambdaTest --
LambdaTest.<init>()
LambdaTest.foo(i)
-LambdaTest.lambda$static$1(arg0)/*synthetic*/
-LambdaTest.lambda$null$0(arg0, arg1)/*synthetic*/
+LambdaTest.lambda$static$1(x1/*synthetic*/)/*synthetic*/
+LambdaTest.lambda$null$0(final cap$0/*synthetic*/, x2/*synthetic*/)/*synthetic*/
static interface LambdaTest$I -- inner
LambdaTest$I.m(x)
--- a/langtools/test/tools/javac/MethodParameters/ReflectionVisitor.java Tue Jan 13 10:17:25 2015 +0100
+++ b/langtools/test/tools/javac/MethodParameters/ReflectionVisitor.java Tue Jan 13 10:25:24 2015 +0100
@@ -277,7 +277,7 @@
param = "final " + param;
}
sb.append(sep).append(param);
- if (!m.isBridge() && !expect.equals(param)) {
+ if (!m.isBridge() && !m.getName().startsWith("lambda$") && !expect.equals(param)) {
error(prefix + "param[" + i + "]='"
+ param + "' expected '" + expect + "'");
break;