compat/maven-model-builder/src/main/java/org/apache/maven/model/interpolation/reflection/MethodMap.java [125:391]:
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        private static final long serialVersionUID = 751688436639650618L;
    }

    private static Method getMostSpecific(List<Method> methods, Class<?>... classes) throws AmbiguousException {
        LinkedList<Method> applicables = getApplicables(methods, classes);

        if (applicables.isEmpty()) {
            return null;
        }

        if (applicables.size() == 1) {
            return applicables.getFirst();
        }

        // This list will contain the maximally specific methods. Hopefully at
        // the end of the below loop, the list will contain exactly one method,
        // (the most specific method) otherwise we have ambiguity.
        LinkedList<Method> maximals = new LinkedList<>();

        for (Method app : applicables) {
            Class<?>[] appArgs = app.getParameterTypes();
            boolean lessSpecific = false;

            for (Iterator<Method> maximal = maximals.iterator(); !lessSpecific && maximal.hasNext(); ) {
                Method max = maximal.next();

                switch (moreSpecific(appArgs, max.getParameterTypes())) {
                    case MORE_SPECIFIC:
                        // This method is more specific than the previously
                        // known maximally specific, so remove the old maximum.
                        maximal.remove();
                        break;

                    case LESS_SPECIFIC:
                        // This method is less specific than some of the
                        // currently known maximally specific methods, so we
                        // won't add it into the set of maximally specific
                        // methods
                        lessSpecific = true;
                        break;

                    default:
                }
            }

            if (!lessSpecific) {
                maximals.addLast(app);
            }
        }

        if (maximals.size() > 1) {
            // We have more than one maximally specific method
            throw new AmbiguousException();
        }

        return maximals.getFirst();
    }

    /**
     * Determines which method signature (represented by a class array) is more
     * specific. This defines a partial ordering on the method signatures.
     *
     * @param c1 first signature to compare
     * @param c2 second signature to compare
     * @return MORE_SPECIFIC if c1 is more specific than c2, LESS_SPECIFIC if
     *         c1 is less specific than c2, INCOMPARABLE if they are incomparable.
     */
    private static int moreSpecific(Class<?>[] c1, Class<?>[] c2) {
        boolean c1MoreSpecific = false;
        boolean c2MoreSpecific = false;

        for (int i = 0; i < c1.length; ++i) {
            if (c1[i] != c2[i]) {
                c1MoreSpecific = c1MoreSpecific || isStrictMethodInvocationConvertible(c2[i], c1[i]);
                c2MoreSpecific = c2MoreSpecific || isStrictMethodInvocationConvertible(c1[i], c2[i]);
            }
        }

        if (c1MoreSpecific) {
            if (c2MoreSpecific) {
                // Incomparable due to cross-assignable arguments (i.e.
                // foo(String, Object) vs. foo(Object, String))
                return INCOMPARABLE;
            }

            return MORE_SPECIFIC;
        }

        if (c2MoreSpecific) {
            return LESS_SPECIFIC;
        }

        // Incomparable due to non-related arguments (i.e.
        // foo(Runnable) vs. foo(Serializable))
        return INCOMPARABLE;
    }

    /**
     * Returns all methods that are applicable to actual argument types.
     *
     * @param methods list of all candidate methods
     * @param classes the actual types of the arguments
     * @return a list that contains only applicable methods (number of
     *         formal and actual arguments matches, and argument types are assignable
     *         to formal types through a method invocation conversion).
     */
    private static LinkedList<Method> getApplicables(List<Method> methods, Class<?>... classes) {
        LinkedList<Method> list = new LinkedList<>();

        for (Method method : methods) {
            if (isApplicable(method, classes)) {
                list.add(method);
            }
        }
        return list;
    }

    /**
     * Returns true if the supplied method is applicable to actual
     * argument types.
     *
     * @param method  The method to check for applicability
     * @param classes The arguments
     * @return true if the method applies to the parameter types
     */
    private static boolean isApplicable(Method method, Class<?>... classes) {
        Class<?>[] methodArgs = method.getParameterTypes();

        if (methodArgs.length != classes.length) {
            return false;
        }

        for (int i = 0; i < classes.length; ++i) {
            if (!isMethodInvocationConvertible(methodArgs[i], classes[i])) {
                return false;
            }
        }

        return true;
    }

    /**
     * Determines whether a type represented by a class object is
     * convertible to another type represented by a class object using a
     * method invocation conversion, treating object types of primitive
     * types as if they were primitive types (that is, a Boolean actual
     * parameter type matches boolean primitive formal type). This behavior
     * is because this method is used to determine applicable methods for
     * an actual parameter list, and primitive types are represented by
     * their object duals in reflective method calls.
     *
     * @param formal the formal parameter type to which the actual
     *               parameter type should be convertible
     * @param actual the actual parameter type.
     * @return true if either formal type is assignable from actual type,
     *         or formal is a primitive type and actual is its corresponding object
     *         type or an object type of a primitive type that can be converted to
     *         the formal type.
     */
    private static boolean isMethodInvocationConvertible(Class<?> formal, Class<?> actual) {
        // if it's a null, it means the arg was null
        if (actual == null && !formal.isPrimitive()) {
            return true;
        }

        // Check for identity or widening reference conversion
        if (actual != null && formal.isAssignableFrom(actual)) {
            return true;
        }

        // Check for boxing with widening primitive conversion. Note that
        // actual parameters are never primitives.
        if (formal.isPrimitive()) {
            if (formal == Boolean.TYPE && actual == Boolean.class) {
                return true;
            }
            if (formal == Character.TYPE && actual == Character.class) {
                return true;
            }
            if (formal == Byte.TYPE && actual == Byte.class) {
                return true;
            }
            if (formal == Short.TYPE && (actual == Short.class || actual == Byte.class)) {
                return true;
            }
            if (formal == Integer.TYPE && (actual == Integer.class || actual == Short.class || actual == Byte.class)) {
                return true;
            }
            if (formal == Long.TYPE
                    && (actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
            if (formal == Float.TYPE
                    && (actual == Float.class
                            || actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
            if (formal == Double.TYPE
                    && (actual == Double.class
                            || actual == Float.class
                            || actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Determines whether a type represented by a class object is
     * convertible to another type represented by a class object using a
     * method invocation conversion, without matching object and primitive
     * types. This method is used to determine the more specific type when
     * comparing signatures of methods.
     *
     * @param formal the formal parameter type to which the actual
     *               parameter type should be convertible
     * @param actual the actual parameter type.
     * @return true if either formal type is assignable from actual type,
     *         or formal and actual are both primitive types and actual can be
     *         subject to widening conversion to formal.
     */
    private static boolean isStrictMethodInvocationConvertible(Class<?> formal, Class<?> actual) {
        // we shouldn't get a null into, but if so
        if (actual == null && !formal.isPrimitive()) {
            return true;
        }

        // Check for identity or widening reference conversion
        if (formal.isAssignableFrom(actual)) {
            return true;
        }

        // Check for widening primitive conversion.
        if (formal.isPrimitive()) {
            if (formal == Short.TYPE && (actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Integer.TYPE && (actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Long.TYPE && (actual == Integer.TYPE || actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Float.TYPE
                    && (actual == Long.TYPE || actual == Integer.TYPE || actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Double.TYPE
                    && (actual == Float.TYPE
                            || actual == Long.TYPE
                            || actual == Integer.TYPE
                            || actual == Short.TYPE
                            || actual == Byte.TYPE)) {
                return true;
            }
        }
        return false;
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impl/maven-impl/src/main/java/org/apache/maven/impl/model/reflection/MethodMap.java [123:389]:
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        private static final long serialVersionUID = 751688436639650618L;
    }

    private static Method getMostSpecific(List<Method> methods, Class<?>... classes) throws AmbiguousException {
        LinkedList<Method> applicables = getApplicables(methods, classes);

        if (applicables.isEmpty()) {
            return null;
        }

        if (applicables.size() == 1) {
            return applicables.getFirst();
        }

        // This list will contain the maximally specific methods. Hopefully at
        // the end of the below loop, the list will contain exactly one method,
        // (the most specific method) otherwise we have ambiguity.
        LinkedList<Method> maximals = new LinkedList<>();

        for (Method app : applicables) {
            Class<?>[] appArgs = app.getParameterTypes();
            boolean lessSpecific = false;

            for (Iterator<Method> maximal = maximals.iterator(); !lessSpecific && maximal.hasNext(); ) {
                Method max = maximal.next();

                switch (moreSpecific(appArgs, max.getParameterTypes())) {
                    case MORE_SPECIFIC:
                        // This method is more specific than the previously
                        // known maximally specific, so remove the old maximum.
                        maximal.remove();
                        break;

                    case LESS_SPECIFIC:
                        // This method is less specific than some of the
                        // currently known maximally specific methods, so we
                        // won't add it into the set of maximally specific
                        // methods
                        lessSpecific = true;
                        break;

                    default:
                }
            }

            if (!lessSpecific) {
                maximals.addLast(app);
            }
        }

        if (maximals.size() > 1) {
            // We have more than one maximally specific method
            throw new AmbiguousException();
        }

        return maximals.getFirst();
    }

    /**
     * Determines which method signature (represented by a class array) is more
     * specific. This defines a partial ordering on the method signatures.
     *
     * @param c1 first signature to compare
     * @param c2 second signature to compare
     * @return MORE_SPECIFIC if c1 is more specific than c2, LESS_SPECIFIC if
     *         c1 is less specific than c2, INCOMPARABLE if they are incomparable.
     */
    private static int moreSpecific(Class<?>[] c1, Class<?>[] c2) {
        boolean c1MoreSpecific = false;
        boolean c2MoreSpecific = false;

        for (int i = 0; i < c1.length; ++i) {
            if (c1[i] != c2[i]) {
                c1MoreSpecific = c1MoreSpecific || isStrictMethodInvocationConvertible(c2[i], c1[i]);
                c2MoreSpecific = c2MoreSpecific || isStrictMethodInvocationConvertible(c1[i], c2[i]);
            }
        }

        if (c1MoreSpecific) {
            if (c2MoreSpecific) {
                // Incomparable due to cross-assignable arguments (i.e.
                // foo(String, Object) vs. foo(Object, String))
                return INCOMPARABLE;
            }

            return MORE_SPECIFIC;
        }

        if (c2MoreSpecific) {
            return LESS_SPECIFIC;
        }

        // Incomparable due to non-related arguments (i.e.
        // foo(Runnable) vs. foo(Serializable))
        return INCOMPARABLE;
    }

    /**
     * Returns all methods that are applicable to actual argument types.
     *
     * @param methods list of all candidate methods
     * @param classes the actual types of the arguments
     * @return a list that contains only applicable methods (number of
     *         formal and actual arguments matches, and argument types are assignable
     *         to formal types through a method invocation conversion).
     */
    private static LinkedList<Method> getApplicables(List<Method> methods, Class<?>... classes) {
        LinkedList<Method> list = new LinkedList<>();

        for (Method method : methods) {
            if (isApplicable(method, classes)) {
                list.add(method);
            }
        }
        return list;
    }

    /**
     * Returns true if the supplied method is applicable to actual
     * argument types.
     *
     * @param method  The method to check for applicability
     * @param classes The arguments
     * @return true if the method applies to the parameter types
     */
    private static boolean isApplicable(Method method, Class<?>... classes) {
        Class<?>[] methodArgs = method.getParameterTypes();

        if (methodArgs.length != classes.length) {
            return false;
        }

        for (int i = 0; i < classes.length; ++i) {
            if (!isMethodInvocationConvertible(methodArgs[i], classes[i])) {
                return false;
            }
        }

        return true;
    }

    /**
     * Determines whether a type represented by a class object is
     * convertible to another type represented by a class object using a
     * method invocation conversion, treating object types of primitive
     * types as if they were primitive types (that is, a Boolean actual
     * parameter type matches boolean primitive formal type). This behavior
     * is because this method is used to determine applicable methods for
     * an actual parameter list, and primitive types are represented by
     * their object duals in reflective method calls.
     *
     * @param formal the formal parameter type to which the actual
     *               parameter type should be convertible
     * @param actual the actual parameter type.
     * @return true if either formal type is assignable from actual type,
     *         or formal is a primitive type and actual is its corresponding object
     *         type or an object type of a primitive type that can be converted to
     *         the formal type.
     */
    private static boolean isMethodInvocationConvertible(Class<?> formal, Class<?> actual) {
        // if it's a null, it means the arg was null
        if (actual == null && !formal.isPrimitive()) {
            return true;
        }

        // Check for identity or widening reference conversion
        if (actual != null && formal.isAssignableFrom(actual)) {
            return true;
        }

        // Check for boxing with widening primitive conversion. Note that
        // actual parameters are never primitives.
        if (formal.isPrimitive()) {
            if (formal == Boolean.TYPE && actual == Boolean.class) {
                return true;
            }
            if (formal == Character.TYPE && actual == Character.class) {
                return true;
            }
            if (formal == Byte.TYPE && actual == Byte.class) {
                return true;
            }
            if (formal == Short.TYPE && (actual == Short.class || actual == Byte.class)) {
                return true;
            }
            if (formal == Integer.TYPE && (actual == Integer.class || actual == Short.class || actual == Byte.class)) {
                return true;
            }
            if (formal == Long.TYPE
                    && (actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
            if (formal == Float.TYPE
                    && (actual == Float.class
                            || actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
            if (formal == Double.TYPE
                    && (actual == Double.class
                            || actual == Float.class
                            || actual == Long.class
                            || actual == Integer.class
                            || actual == Short.class
                            || actual == Byte.class)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Determines whether a type represented by a class object is
     * convertible to another type represented by a class object using a
     * method invocation conversion, without matching object and primitive
     * types. This method is used to determine the more specific type when
     * comparing signatures of methods.
     *
     * @param formal the formal parameter type to which the actual
     *               parameter type should be convertible
     * @param actual the actual parameter type.
     * @return true if either formal type is assignable from actual type,
     *         or formal and actual are both primitive types and actual can be
     *         subject to widening conversion to formal.
     */
    private static boolean isStrictMethodInvocationConvertible(Class<?> formal, Class<?> actual) {
        // we shouldn't get a null into, but if so
        if (actual == null && !formal.isPrimitive()) {
            return true;
        }

        // Check for identity or widening reference conversion
        if (formal.isAssignableFrom(actual)) {
            return true;
        }

        // Check for widening primitive conversion.
        if (formal.isPrimitive()) {
            if (formal == Short.TYPE && (actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Integer.TYPE && (actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Long.TYPE && (actual == Integer.TYPE || actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Float.TYPE
                    && (actual == Long.TYPE || actual == Integer.TYPE || actual == Short.TYPE || actual == Byte.TYPE)) {
                return true;
            }
            if (formal == Double.TYPE
                    && (actual == Float.TYPE
                            || actual == Long.TYPE
                            || actual == Integer.TYPE
                            || actual == Short.TYPE
                            || actual == Byte.TYPE)) {
                return true;
            }
        }
        return false;
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