aoqi@0: /*
aoqi@0:  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: /*
aoqi@0:  * @test
aoqi@0:  * @bug 7118412
aoqi@0:  * @summary Shadowing of type-variables vs. member types
aoqi@0:  */
aoqi@0: import java.io.File;
aoqi@0: import java.io.FileWriter;
aoqi@0: import java.io.IOException;
aoqi@0: import java.io.PrintWriter;
aoqi@0: import java.io.StringWriter;
aoqi@0: 
aoqi@0: public class ShadowingTest {
aoqi@0: 
aoqi@0:     // We generate a method "test" that tries to call T.<something,
aoqi@0:     // depending on the value of MethodCall>.  This controls whether
aoqi@0:     // "test" is static or not.
aoqi@0:     private enum MethodContext {
aoqi@0:         STATIC("static "),
aoqi@0:         INSTANCE("");
aoqi@0: 
aoqi@0:         public final String methodcontext;
aoqi@0: 
aoqi@0:         MethodContext(final String methodcontext) {
aoqi@0:             this.methodcontext = methodcontext;
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     // These control whether or not a type parameter, method type
aoqi@0:     // parameter, or inner class get declared (and in the case of
aoqi@0:     // inner classes, whether it's static or not.
aoqi@0: 
aoqi@0:     private enum MethodTypeParameterDecl {
aoqi@0:         NO(""),
aoqi@0:         YES("<T extends Number> ");
aoqi@0: 
aoqi@0:         public final String tyvar;
aoqi@0: 
aoqi@0:         MethodTypeParameterDecl(final String tyvar) {
aoqi@0:             this.tyvar = tyvar;
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     private enum InsideDef {
aoqi@0:         NONE(""),
aoqi@0:         STATIC("static class T { public void inner() {} }\n"),
aoqi@0:         INSTANCE("class T { public void inner() {} }\n");
aoqi@0: 
aoqi@0:         public final String instancedef;
aoqi@0: 
aoqi@0:         InsideDef(final String instancedef) {
aoqi@0:             this.instancedef = instancedef;
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     private enum TypeParameterDecl {
aoqi@0:         NO(""),
aoqi@0:         YES("<T extends Collection>");
aoqi@0: 
aoqi@0:         public final String tyvar;
aoqi@0: 
aoqi@0:         TypeParameterDecl(final String tyvar) {
aoqi@0:             this.tyvar = tyvar;
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Represents what method we try to call.  This is a way of
aoqi@0:     // checking which T we're seeing.
aoqi@0:     private enum MethodCall {
aoqi@0:         // Method type variables extend Number, so we have intValue
aoqi@0:         METHOD_TYPEVAR("intValue"),
aoqi@0:         // The inner class declaration has a method called "inner"
aoqi@0:         INNER_CLASS("inner"),
aoqi@0:         // The class type variables extend Collection, so we call iterator
aoqi@0:         TYPEVAR("iterator"),
aoqi@0:         // The outer class declaration has a method called "outer"
aoqi@0:         OUTER_CLASS("outer");
aoqi@0: 
aoqi@0:         public final String methodcall;
aoqi@0: 
aoqi@0:         MethodCall(final String methodcall) {
aoqi@0:             this.methodcall = methodcall;
aoqi@0:         }
aoqi@0: 
aoqi@0:     }
aoqi@0: 
aoqi@0:     public boolean succeeds(final MethodCall call,
aoqi@0:                             final MethodTypeParameterDecl mtyvar,
aoqi@0:                             final MethodContext ctx,
aoqi@0:                             final InsideDef inside,
aoqi@0:                             final TypeParameterDecl tyvar) {
aoqi@0:         switch(call) {
aoqi@0:             // We want to resolve to the method type variable
aoqi@0:         case METHOD_TYPEVAR: switch(mtyvar) {
aoqi@0:                 // If the method type variable exists, then T will
aoqi@0:                 // resolve to it, and we'll have intValue.
aoqi@0:             case YES: return true;
aoqi@0:                 // Otherwise, this cannot succeed.
aoqi@0:             default: return false;
aoqi@0:             }
aoqi@0:             // We want to resolve to the inner class
aoqi@0:         case INNER_CLASS: switch(mtyvar) {
aoqi@0:                 // The method type parameter will shadow the inner
aoqi@0:                 // class, so there can't be one.
aoqi@0:             case NO: switch(ctx) {
aoqi@0:                     // If we're not static, then either one should succeed.
aoqi@0:                 case INSTANCE: switch(inside) {
aoqi@0:                     case INSTANCE:
aoqi@0:                     case STATIC:
aoqi@0:                         return true;
aoqi@0:                     default: return false;
aoqi@0:                     }
aoqi@0:                 case STATIC: switch(inside) {
aoqi@0:                         // If we are static, and the inner class is
aoqi@0:                         // static, then we also succeed, because we
aoqi@0:                         // can't see the type variable.
aoqi@0:                     case STATIC: return true;
aoqi@0:                     case INSTANCE: switch(tyvar) {
aoqi@0:                             // If we're calling from a non-static
aoqi@0:                             // context, there can't be a class type
aoqi@0:                             // variable, because that will shadow the
aoqi@0:                             // static inner class definition.
aoqi@0:                         case NO: return true;
aoqi@0:                         default: return false;
aoqi@0:                         }
aoqi@0:                         // If the inner class isn't declared, we can't
aoqi@0:                         // see it.
aoqi@0:                     default: return false;
aoqi@0:                     }
aoqi@0:                     // Can't get here.
aoqi@0:                 default: return false;
aoqi@0:                 }
aoqi@0:             default: return false;
aoqi@0:             }
aoqi@0:             // We want to resolve to the class type parameter
aoqi@0:         case TYPEVAR: switch(mtyvar) {
aoqi@0:                 // We can't have a method type parameter, as that would
aoqi@0:                 // shadow the class type parameter
aoqi@0:             case NO: switch(ctx) {
aoqi@0:                 case INSTANCE: switch(inside) {
aoqi@0:                         // We have to be in an instance context.  If
aoqi@0:                         // we're static, we can't see the type
aoqi@0:                         // variable.
aoqi@0:                     case NONE: switch(tyvar) {
aoqi@0:                             // Obviously, the type parameter has to be declared.
aoqi@0:                         case YES: return true;
aoqi@0:                         default: return false;
aoqi@0:                         }
aoqi@0:                     default: return false;
aoqi@0:                     }
aoqi@0:                 default: return false;
aoqi@0:                 }
aoqi@0:             default: return false;
aoqi@0:             }
aoqi@0:             // We want to resolve to the outer class
aoqi@0:         case OUTER_CLASS: switch(mtyvar) {
aoqi@0:             case NO: switch(inside) {
aoqi@0:                 case NONE: switch(tyvar) {
aoqi@0:                         // Basically, nothing else can be declared, or
aoqi@0:                         // else we can't see it.  Even if our context
aoqi@0:                         // is static, the compiler will complain if
aoqi@0:                         // non-static T's exist, because they will
aoqi@0:                         // shadow the outer class.
aoqi@0:                     case NO: return true;
aoqi@0:                     default: return false;
aoqi@0:                     }
aoqi@0:                 default: return false;
aoqi@0:                 }
aoqi@0:             default: return false;
aoqi@0:             }
aoqi@0:         }
aoqi@0:         return false;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private static final File classesdir = new File("7118412");
aoqi@0: 
aoqi@0:     private int errors = 0;
aoqi@0: 
aoqi@0:     private int dirnum = 0;
aoqi@0: 
aoqi@0:     private void doTest(final MethodTypeParameterDecl mtyvar,
aoqi@0:                         final TypeParameterDecl tyvar,
aoqi@0:                         final InsideDef insidedef, final MethodContext ctx,
aoqi@0:                         final MethodCall call)
aoqi@0:         throws IOException {
aoqi@0:         final String content = "import java.util.Collection;\n" +
aoqi@0:             "class Test" + tyvar.tyvar + " {\n" +
aoqi@0:             "  " + insidedef.instancedef +
aoqi@0:             "  " + ctx.methodcontext + mtyvar.tyvar + "void test(T t) { t." +
aoqi@0:             call.methodcall + "(); }\n" +
aoqi@0:             "}\n" +
aoqi@0:             "class T { void outer() {} }\n";
aoqi@0:         final File dir = new File(classesdir, "" + dirnum);
aoqi@0:         final File Test_java = writeFile(dir, "Test.java", content);
aoqi@0:         dirnum++;
aoqi@0:         if(succeeds(call, mtyvar, ctx, insidedef, tyvar)) {
aoqi@0:             if(!assert_compile_succeed(Test_java))
aoqi@0:                 System.err.println("Failed file:\n" + content);
aoqi@0:         }
aoqi@0:         else {
aoqi@0:             if(!assert_compile_fail(Test_java))
aoqi@0:                 System.err.println("Failed file:\n" + content);
aoqi@0:         }
aoqi@0:     }
aoqi@0: 
aoqi@0:     private void run() throws Exception {
aoqi@0:         classesdir.mkdir();
aoqi@0:         for(MethodTypeParameterDecl mtyvar : MethodTypeParameterDecl.values())
aoqi@0:             for(TypeParameterDecl tyvar : TypeParameterDecl.values())
aoqi@0:                 for(InsideDef insidedef : InsideDef.values())
aoqi@0:                     for(MethodContext ctx : MethodContext.values())
aoqi@0:                         for(MethodCall methodcall : MethodCall.values())
aoqi@0:                             doTest(mtyvar, tyvar, insidedef, ctx, methodcall);
aoqi@0:         if (errors != 0)
aoqi@0:             throw new Exception("ShadowingTest test failed with " +
aoqi@0:                                 errors + " errors.");
aoqi@0:     }
aoqi@0: 
aoqi@0:     private boolean assert_compile_fail(final File file) {
aoqi@0:         final String filename = file.getPath();
aoqi@0:         final String[] args = { filename };
aoqi@0:         final StringWriter sw = new StringWriter();
aoqi@0:         final PrintWriter pw = new PrintWriter(sw);
aoqi@0:         final int rc = com.sun.tools.javac.Main.compile(args, pw);
aoqi@0:         pw.close();
aoqi@0:         if (rc == 0) {
aoqi@0:             System.err.println("Compilation of " + file.getName() +
aoqi@0:                                " didn't fail as expected.");
aoqi@0:             errors++;
aoqi@0:             return false;
aoqi@0:         } else return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private boolean assert_compile_succeed(final File file) {
aoqi@0:         final String filename = file.getPath();
aoqi@0:         final String[] args = { filename };
aoqi@0:         final StringWriter sw = new StringWriter();
aoqi@0:         final PrintWriter pw = new PrintWriter(sw);
aoqi@0:         final int rc = com.sun.tools.javac.Main.compile(args, pw);
aoqi@0:         pw.close();
aoqi@0:         if (rc != 0) {
aoqi@0:             System.err.println("Compilation of " + file.getName() +
aoqi@0:                                " didn't succeed as expected.  Output:");
aoqi@0:             System.err.println(sw.toString());
aoqi@0:             errors++;
aoqi@0:             return false;
aoqi@0:         } else return true;
aoqi@0:     }
aoqi@0: 
aoqi@0:     private File writeFile(final File dir,
aoqi@0:                            final String path,
aoqi@0:                            final String body) throws IOException {
aoqi@0:         final File f = new File(dir, path);
aoqi@0:         f.getParentFile().mkdirs();
aoqi@0:         final FileWriter out = new FileWriter(f);
aoqi@0:         out.write(body);
aoqi@0:         out.close();
aoqi@0:         return f;
aoqi@0:     }
aoqi@0: 
aoqi@0:     public static void main(String... args) throws Exception {
aoqi@0:         new ShadowingTest().run();
aoqi@0:     }
aoqi@0: 
aoqi@0: }