8029721: javac crash for annotated parameter type of lambda in a field

Reviewed-by: rfield, jfranck

src/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -2590,15 +2590,61 @@ public class Attr extends JCTree.Visitor {
             }
         }
 
+        /* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
+         * static field and that lambda has type annotations, these annotations will
+         * also be stored at these fake clinit methods.
+         *
+         * LambdaToMethod also use fake clinit methods so they can be reused.
+         * Also as LTM is a phase subsequent to attribution, the methods from
+         * clinits can be safely removed by LTM to save memory.
+         */
+        private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
+
+        public MethodSymbol removeClinit(ClassSymbol sym) {
+            return clinits.remove(sym);
+        }
+
+        /* This method returns an environment to be used to attribute a lambda
+         * expression.
+         *
+         * The owner of this environment is a method symbol. If the current owner
+         * is not a method, for example if the lambda is used to initialize
+         * a field, then if the field is:
+         *
+         * - an instance field, we use the first constructor.
+         * - a static field, we create a fake clinit method.
+         */
         private Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
             Env<AttrContext> lambdaEnv;
             Symbol owner = env.info.scope.owner;
             if (owner.kind == VAR && owner.owner.kind == TYP) {
                 //field initializer
                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared()));
-                lambdaEnv.info.scope.owner =
-                    new MethodSymbol((owner.flags() & STATIC) | BLOCK, names.empty, null,
-                                     env.info.scope.owner);
+                ClassSymbol enclClass = owner.enclClass();
+                /* if the field isn't static, then we can get the first constructor
+                 * and use it as the owner of the environment. This is what
+                 * LTM code is doing to look for type annotations so we are fine.
+                 */
+                if ((owner.flags() & STATIC) == 0) {
+                    for (Symbol s : enclClass.members_field.getElementsByName(names.init)) {
+                        lambdaEnv.info.scope.owner = s;
+                        break;
+                    }
+                } else {
+                    /* if the field is static then we need to create a fake clinit
+                     * method, this method can later be reused by LTM.
+                     */
+                    MethodSymbol clinit = clinits.get(enclClass);
+                    if (clinit == null) {
+                        Type clinitType = new MethodType(List.<Type>nil(),
+                                syms.voidType, List.<Type>nil(), syms.methodClass);
+                        clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
+                                names.clinit, clinitType, enclClass);
+                        clinit.params = List.<VarSymbol>nil();
+                        clinits.put(enclClass, clinit);
+                    }
+                    lambdaEnv.info.scope.owner = clinit;
+                }
             } else {
                 lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
             }

src/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java

@@ -1474,12 +1474,27 @@ public class LambdaToMethod extends TreeTranslator {
         private Symbol initSym(ClassSymbol csym, long flags) {
             boolean isStatic = (flags & STATIC) != 0;
             if (isStatic) {
-                //static clinits are generated in Gen - so we need to fake them
-                Symbol clinit = clinits.get(csym);
+                /* static clinits are generated in Gen, so we need to use a fake
+                 * one. Attr creates a fake clinit method while attributing
+                 * lambda expressions used as initializers of static fields, so
+                 * let's use that one.
+                 */
+                MethodSymbol clinit = attr.removeClinit(csym);
+                if (clinit != null) {
+                    clinits.put(csym, clinit);
+                    return clinit;
+                }
+
+                /* if no clinit is found at Attr, then let's try at clinits.
+                 */
+                clinit = (MethodSymbol)clinits.get(csym);
                 if (clinit == null) {
+                    /* no luck, let's create a new one
+                     */
                     clinit = makePrivateSyntheticMethod(STATIC,
                             names.clinit,
-                            new MethodType(List.<Type>nil(), syms.voidType, List.<Type>nil(), syms.methodClass),
+                            new MethodType(List.<Type>nil(), syms.voidType,
+                                List.<Type>nil(), syms.methodClass),
                             csym);
                     clinits.put(csym, clinit);
                 }

test/tools/javac/annotations/typeAnnotations/newlocations/Lambda.java

@@ -23,8 +23,9 @@
 
 /*
  * @test
- * @bug 8008077
+ * @bug 8008077 8029721
  * @summary new type annotation location: lambda expressions
+ * javac crash for annotated parameter type of lambda in a field
  * @compile Lambda.java
  * @author Werner Dietl
  */
@@ -57,6 +58,14 @@ public class Lambda {
     LambdaInt2 getLambda() {
         return (@TA Object x, @TB Object y) -> { @TA Object l = null; System.out.println("We have: " + (@TB Object) x); };
     }
+
+    java.util.function.IntUnaryOperator x = (@TA int y) -> 1;
+
+    static java.util.function.IntUnaryOperator xx = (@TA int y) -> 1;
+
+    java.util.function.IntUnaryOperator foo() {
+        return (@TA int y) -> 2;
+    }
 }
 
 @Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER})

test/tools/javac/annotations/typeAnnotations/referenceinfos/Lambda.java

@@ -23,8 +23,9 @@
 
 /*
  * @test
- * @bug 8008077
+ * @bug 8008077 8029721
  * @summary Test population of reference info for lambda expressions
+ * javac crash for annotated parameter type of lambda in a field
  * @compile -g Driver.java ReferenceInfoUtil.java Lambda.java
  * @run main Driver Lambda
  * @author Werner Dietl
@@ -285,4 +286,24 @@ public class Lambda {
                 "  }" +
                 "}";
     }
+
+    @TADescriptions({
+        @TADescription(annotation = "TA", type = METHOD_FORMAL_PARAMETER,
+            paramIndex = 0)})
+    public String lambdaField1() {
+        return
+            "class Test {" +
+                " java.util.function.IntUnaryOperator field = (@TA int y) -> 1;" +
+            "}";
+    }
+
+    @TADescriptions({
+        @TADescription(annotation = "TA", type = METHOD_FORMAL_PARAMETER,
+            paramIndex = 0)})
+    public String lambdaField2() {
+        return
+            "class Test {" +
+                " static java.util.function.IntUnaryOperator field = (@TA int y) -> 1;" +
+            "}";
+    }
 }

test/tools/javac/lambda/LambdaScope05.out

 LambdaScope05.java:13:47: compiler.err.already.defined.in.clinit: kindname.variable, p, kindname.static.init, kindname.class, LambdaScope05
-LambdaScope05.java:14:40: compiler.err.already.defined.in.clinit: kindname.variable, p, kindname.instance.init, kindname.class, LambdaScope05
+LambdaScope05.java:14:40: compiler.err.already.defined: kindname.variable, p, kindname.constructor, LambdaScope05()
 LambdaScope05.java:17:43: compiler.err.already.defined.in.clinit: kindname.variable, p, kindname.static.init, kindname.class, LambdaScope05
 LambdaScope05.java:21:43: compiler.err.already.defined.in.clinit: kindname.variable, p, kindname.instance.init, kindname.class, LambdaScope05
 LambdaScope05.java:25:43: compiler.err.already.defined: kindname.variable, p, kindname.method, m_static()