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23 
24 /*
25  * @test
26  * @bug 5041784
27  * @summary Check that plain arrays like String[] are never represented as
28  * GenericArrayType.
29  * @author Eamonn McManus
30  */
31 
32 import java.lang.reflect.Constructor;
33 import java.lang.reflect.GenericArrayType;
34 import java.lang.reflect.GenericDeclaration;
35 import java.lang.reflect.Method;
36 import java.lang.reflect.ParameterizedType;
37 import java.lang.reflect.Type;
38 import java.lang.reflect.TypeVariable;
39 import java.lang.reflect.WildcardType;
40 import java.util.HashSet;
41 import java.util.List;
42 import java.util.Map;
43 import java.util.Set;
44 
45 public class TestPlainArrayNotGeneric {
m1(List<String> p1)46     public String[] m1(List<String> p1) {return null;}
m2(String[] p1)47     public List<String> m2(String[] p1) {return null;}
m3(List<String> p1, String[] p2)48     public void m3(List<String> p1, String[] p2) {}
m4(List<String[]> p1)49     public void m4(List<String[]> p1) {}
TestPlainArrayNotGeneric(List<String[]> p1)50     public TestPlainArrayNotGeneric(List<String[]> p1) {}
TestPlainArrayNotGeneric(List<String> p1, String[] p2)51     public TestPlainArrayNotGeneric(List<String> p1, String[] p2) {}
52 
m5(T p1)53     public <T extends List<String[]>> T m5(T p1) {return null;}
m6(T[] p1, List<T[]> p2)54     public <T extends Object> T[] m6(T[] p1, List<T[]> p2) {return null;}
55 
m6(List<? extends Object[]> p1)56     public List<? extends Object[]> m6(List<? extends Object[]> p1) {return null;}
m7(T[] p1)57     public <T extends List<? extends Object[]>> T m7(T[] p1) {return null;}
m8(List<? super Object[]> p1)58     public List<? super Object[]> m8(List<? super Object[]> p1) {return null;}
m9(T[] p1)59     public <T extends List<? super Object[]>> T[] m9(T[] p1) {return null;}
60 
61     public static interface XMap extends Map<List<String[]>, String[]> {}
62     public static interface YMap<K extends List<String[]>, V>
63             extends Map<K[], V[]> {}
64 
65 
66     private static String lastFailure;
67     private static int failureCount;
68 
main(String[] args)69     public static void main(String[] args) throws Exception {
70         checkClass(TestPlainArrayNotGeneric.class);
71 
72         if (failureCount == 0)
73             System.out.println("TEST PASSED");
74         else
75             throw new Exception("TEST FAILED: Last failure: " + lastFailure);
76     }
77 
checkClass(Class<?> c)78     private static void checkClass(Class<?> c) throws Exception {
79         Method[] methods = c.getMethods();
80         for (Method m : methods) {
81             check(m.getGenericReturnType(), "return type of method " + m);
82             check(m.getGenericParameterTypes(), "parameter", "method " + m);
83             check(m.getTypeParameters(), "type parameter", "method " + m);
84         }
85 
86         Constructor[] constructors = c.getConstructors();
87         for (Constructor constr : constructors) {
88             check(constr.getGenericParameterTypes(), "parameter",
89                     "constructor " + constr);
90             check(constr.getTypeParameters(), "type parameter",
91                     "constructor " + constr);
92         }
93 
94         Class<?>[] inners = c.getDeclaredClasses();
95         for (Class inner : inners)
96             checkClass(inner);
97     }
98 
check(Type[] types, String elementKind, String what)99     private static void check(Type[] types, String elementKind, String what) {
100         for (int i = 0; i < types.length; i++) {
101             Type t = types[i];
102             check(t, elementKind + " " + (i+1) + " of " + what);
103         }
104     }
105 
106     private static final Set<Type> checking = new HashSet<>();
107 
check(Type t, String what)108     private static void check(Type t, String what) {
109         if (t == null || !checking.add(t))
110             return;
111         // Avoid infinite recursion.  t can be null e.g. for superclass of Object.
112         try {
113             check2(t, what);
114         } finally {
115             checking.remove(t);
116         }
117     }
118 
check2(Type t, String what)119     private static void check2(Type t, String what) {
120         if (t instanceof ParameterizedType) {
121             ParameterizedType pt = (ParameterizedType) t;
122             check(pt.getActualTypeArguments(), "type argument", what);
123         } else if (t instanceof TypeVariable) {
124             TypeVariable<?> tv = (TypeVariable<?>) t;
125             check(tv.getBounds(), "bound", what);
126             GenericDeclaration gd = tv.getGenericDeclaration();
127             if (gd instanceof Type)
128                 check((Type) gd, "declaration containing " + what);
129         } else if (t instanceof WildcardType) {
130             WildcardType wt = (WildcardType) t;
131             check(wt.getLowerBounds(), "lower bound", "wildcard type in " + what);
132             check(wt.getUpperBounds(), "upper bound", "wildcard type in " + what);
133         } else if (t instanceof Class<?>) {
134             Class<?> c = (Class<?>) t;
135             check(c.getGenericInterfaces(), "superinterface", c.toString());
136             check(c.getGenericSuperclass(), "superclass of " + c);
137             check(c.getTypeParameters(), "type parameter", c.toString());
138         } else if (t instanceof GenericArrayType) {
139             GenericArrayType gat = (GenericArrayType) t;
140             Type comp = gat.getGenericComponentType();
141             if (comp instanceof Class) {
142                 fail("Type " + t + " uses GenericArrayType when plain " +
143                         "array would do, in " + what);
144             } else
145                 check(comp, "component type of " + what);
146         } else {
147             fail("TEST BUG: mutant Type " + t + " (a " + t.getClass().getName() + ")");
148         }
149     }
150 
fail(String why)151     private static void fail(String why) {
152         System.out.println("FAIL: " + why);
153         lastFailure = why;
154         failureCount++;
155     }
156 }
157