1.1 --- a/src/share/classes/com/sun/tools/javac/comp/Infer.java Thu Oct 04 13:04:53 2012 +0100
1.2 +++ b/src/share/classes/com/sun/tools/javac/comp/Infer.java Fri Oct 05 14:35:24 2012 +0100
1.3 @@ -274,7 +274,7 @@
1.4 Resolve.MethodResolutionContext resolveContext,
1.5 Warner warn) throws InferenceException {
1.6 //-System.err.println("instantiateMethod(" + tvars + ", " + mt + ", " + argtypes + ")"); //DEBUG
1.7 - final InferenceContext inferenceContext = new InferenceContext(tvars, this);
1.8 + final InferenceContext inferenceContext = new InferenceContext(tvars, this, true);
1.9 inferenceException.clear();
1.10
1.11 try {
1.12 @@ -467,6 +467,75 @@
1.13 throw bk.setMessage(inferenceException, uv);
1.14 }
1.15
1.16 + // <editor-fold desc="functional interface instantiation">
1.17 + /**
1.18 + * This method is used to infer a suitable target functional interface in case
1.19 + * the original parameterized interface contains wildcards. An inference process
1.20 + * is applied so that wildcard bounds, as well as explicit lambda/method ref parameters
1.21 + * (where applicable) are used to constraint the solution.
1.22 + */
1.23 + public Type instantiateFunctionalInterface(DiagnosticPosition pos, Type funcInterface,
1.24 + List<Type> paramTypes, Check.CheckContext checkContext) {
1.25 + if (types.capture(funcInterface) == funcInterface) {
1.26 + //if capture doesn't change the type then return the target unchanged
1.27 + //(this means the target contains no wildcards!)
1.28 + return funcInterface;
1.29 + } else {
1.30 + Type formalInterface = funcInterface.tsym.type;
1.31 + InferenceContext funcInterfaceContext =
1.32 + new InferenceContext(funcInterface.tsym.type.getTypeArguments(), this, false);
1.33 + if (paramTypes != null) {
1.34 + //get constraints from explicit params (this is done by
1.35 + //checking that explicit param types are equal to the ones
1.36 + //in the functional interface descriptors)
1.37 + List<Type> descParameterTypes = types.findDescriptorType(formalInterface).getParameterTypes();
1.38 + if (descParameterTypes.size() != paramTypes.size()) {
1.39 + checkContext.report(pos, diags.fragment("incompatible.arg.types.in.lambda"));
1.40 + return types.createErrorType(funcInterface);
1.41 + }
1.42 + for (Type p : descParameterTypes) {
1.43 + if (!types.isSameType(funcInterfaceContext.asFree(p, types), paramTypes.head)) {
1.44 + checkContext.report(pos, diags.fragment("no.suitable.functional.intf.inst", funcInterface));
1.45 + return types.createErrorType(funcInterface);
1.46 + }
1.47 + paramTypes = paramTypes.tail;
1.48 + }
1.49 + for (Type t : funcInterfaceContext.undetvars) {
1.50 + UndetVar uv = (UndetVar)t;
1.51 + minimizeInst(uv, Warner.noWarnings);
1.52 + if (uv.inst == null &&
1.53 + Type.filter(uv.getBounds(InferenceBound.UPPER), boundFilter).nonEmpty()) {
1.54 + maximizeInst(uv, Warner.noWarnings);
1.55 + }
1.56 + }
1.57 +
1.58 + formalInterface = funcInterfaceContext.asInstType(formalInterface, types);
1.59 + }
1.60 + ListBuffer<Type> typeargs = ListBuffer.lb();
1.61 + List<Type> actualTypeargs = funcInterface.getTypeArguments();
1.62 + //for remaining uninferred type-vars in the functional interface type,
1.63 + //simply replace the wildcards with its bound
1.64 + for (Type t : formalInterface.getTypeArguments()) {
1.65 + if (actualTypeargs.head.tag == WILDCARD) {
1.66 + WildcardType wt = (WildcardType)actualTypeargs.head;
1.67 + typeargs.append(wt.type);
1.68 + } else {
1.69 + typeargs.append(actualTypeargs.head);
1.70 + }
1.71 + actualTypeargs = actualTypeargs.tail;
1.72 + }
1.73 + Type owntype = types.subst(formalInterface, funcInterfaceContext.inferenceVars(), typeargs.toList());
1.74 + if (!chk.checkValidGenericType(owntype)) {
1.75 + //if the inferred functional interface type is not well-formed,
1.76 + //or if it's not a subtype of the original target, issue an error
1.77 + checkContext.report(pos, diags.fragment("no.suitable.functional.intf.inst", funcInterface));
1.78 + return types.createErrorType(funcInterface);
1.79 + }
1.80 + return owntype;
1.81 + }
1.82 + }
1.83 + // </editor-fold>
1.84 +
1.85 /**
1.86 * Compute a synthetic method type corresponding to the requested polymorphic
1.87 * method signature. The target return type is computed from the immediately
1.88 @@ -536,9 +605,17 @@
1.89 * Mapping that turns inference variables into undet vars
1.90 * (used by inference context)
1.91 */
1.92 - Mapping fromTypeVarFun = new Mapping("fromTypeVarFun") {
1.93 + class FromTypeVarFun extends Mapping {
1.94 +
1.95 + boolean includeBounds;
1.96 +
1.97 + FromTypeVarFun(boolean includeBounds) {
1.98 + super("fromTypeVarFunWithBounds");
1.99 + this.includeBounds = includeBounds;
1.100 + }
1.101 +
1.102 public Type apply(Type t) {
1.103 - if (t.tag == TYPEVAR) return new UndetVar((TypeVar)t, types);
1.104 + if (t.tag == TYPEVAR) return new UndetVar((TypeVar)t, types, includeBounds);
1.105 else return t.map(this);
1.106 }
1.107 };
1.108 @@ -573,8 +650,8 @@
1.109
1.110 List<FreeTypeListener> freetypeListeners = List.nil();
1.111
1.112 - public InferenceContext(List<Type> inferencevars, Infer infer) {
1.113 - this.undetvars = Type.map(inferencevars, infer.fromTypeVarFun);
1.114 + public InferenceContext(List<Type> inferencevars, Infer infer, boolean includeBounds) {
1.115 + this.undetvars = Type.map(inferencevars, infer.new FromTypeVarFun(includeBounds));
1.116 this.inferencevars = inferencevars;
1.117 }
1.118
1.119 @@ -737,5 +814,5 @@
1.120 }
1.121 }
1.122
1.123 - final InferenceContext emptyContext = new InferenceContext(List.<Type>nil(), this);
1.124 + final InferenceContext emptyContext = new InferenceContext(List.<Type>nil(), this, false);
1.125 }
