--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Resolve.java Wed Jan 18 18:26:36 2012 -0800
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Resolve.java Tue Jan 24 17:52:02 2012 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2012, 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
@@ -474,52 +474,126 @@
return false;
}
}
+ /**
+ * A check handler is used by the main method applicability routine in order
+ * to handle specific method applicability failures. It is assumed that a class
+ * implementing this interface should throw exceptions that are a subtype of
+ * InapplicableMethodException (see below). Such exception will terminate the
+ * method applicability check and propagate important info outwards (for the
+ * purpose of generating better diagnostics).
+ */
+ interface MethodCheckHandler {
+ /* The number of actuals and formals differ */
+ InapplicableMethodException arityMismatch();
+ /* An actual argument type does not conform to the corresponding formal type */
+ InapplicableMethodException argumentMismatch(boolean varargs, Type found, Type expected);
+ /* The element type of a varargs is not accessible in the current context */
+ InapplicableMethodException inaccessibleVarargs(Symbol location, Type expected);
+ }
+
+ /**
+ * Basic method check handler used within Resolve - all methods end up
+ * throwing InapplicableMethodException; a diagnostic fragment that describes
+ * the cause as to why the method is not applicable is set on the exception
+ * before it is thrown.
+ */
+ MethodCheckHandler resolveHandler = new MethodCheckHandler() {
+ public InapplicableMethodException arityMismatch() {
+ return inapplicableMethodException.setMessage("arg.length.mismatch");
+ }
+ public InapplicableMethodException argumentMismatch(boolean varargs, Type found, Type expected) {
+ String key = varargs ?
+ "varargs.argument.mismatch" :
+ "no.conforming.assignment.exists";
+ return inapplicableMethodException.setMessage(key,
+ found, expected);
+ }
+ public InapplicableMethodException inaccessibleVarargs(Symbol location, Type expected) {
+ return inapplicableMethodException.setMessage("inaccessible.varargs.type",
+ expected, Kinds.kindName(location), location);
+ }
+ };
+
void checkRawArgumentsAcceptable(Env<AttrContext> env,
List<Type> argtypes,
List<Type> formals,
boolean allowBoxing,
boolean useVarargs,
Warner warn) {
+ checkRawArgumentsAcceptable(env, List.<Type>nil(), argtypes, formals,
+ allowBoxing, useVarargs, warn, resolveHandler);
+ }
+
+ /**
+ * Main method applicability routine. Given a list of actual types A,
+ * a list of formal types F, determines whether the types in A are
+ * compatible (by method invocation conversion) with the types in F.
+ *
+ * Since this routine is shared between overload resolution and method
+ * type-inference, it is crucial that actual types are converted to the
+ * corresponding 'undet' form (i.e. where inference variables are replaced
+ * with undetvars) so that constraints can be propagated and collected.
+ *
+ * Moreover, if one or more types in A is a poly type, this routine calls
+ * Infer.instantiateArg in order to complete the poly type (this might involve
+ * deferred attribution).
+ *
+ * A method check handler (see above) is used in order to report errors.
+ */
+ List<Type> checkRawArgumentsAcceptable(Env<AttrContext> env,
+ List<Type> undetvars,
+ List<Type> argtypes,
+ List<Type> formals,
+ boolean allowBoxing,
+ boolean useVarargs,
+ Warner warn,
+ MethodCheckHandler handler) {
Type varargsFormal = useVarargs ? formals.last() : null;
+ ListBuffer<Type> checkedArgs = ListBuffer.lb();
+
if (varargsFormal == null &&
argtypes.size() != formals.size()) {
- throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
+ throw handler.arityMismatch(); // not enough args
}
while (argtypes.nonEmpty() && formals.head != varargsFormal) {
- boolean works = allowBoxing
- ? types.isConvertible(argtypes.head, formals.head, warn)
- : types.isSubtypeUnchecked(argtypes.head, formals.head, warn);
- if (!works)
- throw inapplicableMethodException.setMessage("no.conforming.assignment.exists",
- argtypes.head,
- formals.head);
+ Type undetFormal = infer.asUndetType(formals.head, undetvars);
+ Type capturedActual = types.capture(argtypes.head);
+ boolean works = allowBoxing ?
+ types.isConvertible(capturedActual, undetFormal, warn) :
+ types.isSubtypeUnchecked(capturedActual, undetFormal, warn);
+ if (!works) {
+ throw handler.argumentMismatch(false, argtypes.head, formals.head);
+ }
+ checkedArgs.append(capturedActual);
argtypes = argtypes.tail;
formals = formals.tail;
}
- if (formals.head != varargsFormal)
- throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
+ if (formals.head != varargsFormal) {
+ throw handler.arityMismatch(); // not enough args
+ }
if (useVarargs) {
+ //note: if applicability check is triggered by most specific test,
+ //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
Type elt = types.elemtype(varargsFormal);
+ Type eltUndet = infer.asUndetType(elt, undetvars);
while (argtypes.nonEmpty()) {
- if (!types.isConvertible(argtypes.head, elt, warn))
- throw inapplicableMethodException.setMessage("varargs.argument.mismatch",
- argtypes.head,
- elt);
+ Type capturedActual = types.capture(argtypes.head);
+ if (!types.isConvertible(capturedActual, eltUndet, warn)) {
+ throw handler.argumentMismatch(true, argtypes.head, elt);
+ }
+ checkedArgs.append(capturedActual);
argtypes = argtypes.tail;
}
//check varargs element type accessibility
- if (!isAccessible(env, elt)) {
+ if (undetvars.isEmpty() && !isAccessible(env, elt)) {
Symbol location = env.enclClass.sym;
- throw inapplicableMethodException.setMessage("inaccessible.varargs.type",
- elt,
- Kinds.kindName(location),
- location);
+ throw handler.inaccessibleVarargs(location, elt);
}
}
- return;
+ return checkedArgs.toList();
}
// where
public static class InapplicableMethodException extends RuntimeException {