test/langtools/tools/javac/versions/Versions.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2014, 2017, 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
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /*
  * @test
  * @bug 4981566 5028634 5094412 6304984 7025786 7025789 8001112 8028545 8000961 8030610 8028546 8188870 8173382 8173382
  * @summary Check interpretation of -target and -source options
  * @modules java.compiler
  *          jdk.compiler
  * @run main Versions
  */

 import java.io.*;
 import java.nio.*;
 import java.nio.channels.*;

 import javax.tools.JavaCompiler;
 import javax.tools.ToolProvider;
 import javax.tools.JavaFileObject;
 import javax.tools.StandardJavaFileManager;
 import java.util.List;
 import java.util.ArrayList;
 import java.util.Arrays;


 public class Versions {

     protected JavaCompiler javacompiler;
     protected int failedCases;

     public Versions() throws IOException {
         javacompiler = ToolProvider.getSystemJavaCompiler();
         genSourceFiles();
         failedCases = 0;
     }

     public static void main(String... args) throws IOException {
         Versions versions = new Versions();
         versions.run();
     }

     void run() {

         String TC = "";
         System.out.println("Version.java: Starting");

         check("55.0");
         check("55.0", "-source 1.6");
         check("55.0", "-source 1.7");
         check("55.0", "-source 1.8");
         check("55.0", "-source 1.9");
         check("55.0", "-source 1.10");
         check("55.0", "-source 11");

         check_source_target(true, "50.0", "6", "6");
         check_source_target(true, "51.0", "6", "7");
         check_source_target(true, "51.0", "7", "7");
         check_source_target(true, "52.0", "6", "8");
         check_source_target(true, "52.0", "7", "8");
         check_source_target(true, "52.0", "8", "8");
         check_source_target(true, "53.0", "6", "9");
         check_source_target(true, "53.0", "7", "9");
         check_source_target(true, "53.0", "8", "9");
         check_source_target(true, "53.0", "9", "9");
         check_source_target(true, "54.0", "6", "10");
         check_source_target(true, "54.0", "7", "10");
         check_source_target(true, "54.0", "8", "10");
         check_source_target(true, "54.0", "9", "10");
         check_source_target(true, "54.0", "10", "10");
         check_source_target(false, "55.0", "6", "11");
         check_source_target(false, "55.0", "7", "11");
         check_source_target(false, "55.0", "8", "11");
         check_source_target(false, "55.0", "9", "11");
         check_source_target(false, "55.0", "10", "11");
         check_source_target(false, "55.0", "11", "11");

         checksrc16("-source 1.6");
         checksrc16("-source 6");
         checksrc16("-source 1.6", "-target 1.6");
         checksrc16("-source 6", "-target 6");
         checksrc17("-source 1.7");
         checksrc17("-source 7");
         checksrc17("-source 1.7", "-target 1.7");
         checksrc17("-source 7", "-target 7");
         checksrc18("-source 1.8");
         checksrc18("-source 8");
         checksrc18("-source 1.8", "-target 1.8");
         checksrc18("-source 8", "-target 8");
         checksrc19("-source 1.9");
         checksrc19("-source 9");
         checksrc19("-source 1.9", "-target 1.9");
         checksrc19("-source 9", "-target 9");
         checksrc110();
         checksrc110("-source 1.10");
         checksrc110("-source 10");
         checksrc110("-source 1.10", "-target 1.10");
         checksrc110("-source 10", "-target 10");
         checksrc111("-source 11");
         checksrc111("-source 11", "-target 11");
         checksrc111("-target 11");

         fail("-source 7", "-target 1.6", "Base.java");
         fail("-source 8", "-target 1.6", "Base.java");
         fail("-source 8", "-target 1.7", "Base.java");
         fail("-source 9", "-target 1.7", "Base.java");
         fail("-source 9", "-target 1.8", "Base.java");
         fail("-source 10", "-target 1.7", "Base.java");
         fail("-source 10", "-target 1.8", "Base.java");
         fail("-source 11", "-target 1.9", "Base.java");
         fail("-source 11", "-target 1.10", "Base.java");

         fail("-source 1.5", "-target 1.5", "Base.java");
         fail("-source 1.4", "-target 1.4", "Base.java");
         fail("-source 1.3", "-target 1.3", "Base.java");
         fail("-source 1.2", "-target 1.2", "Base.java");

         if (failedCases > 0) {
             System.err.println("failedCases = " + String.valueOf(failedCases));
             throw new Error("Test failed");
         }

     }

     protected void printargs(String fname,String... args) {
         System.out.printf("test: %s", fname);
         for (String onearg : args) {
             System.out.printf(" %s", onearg);
         }
         System.out.printf("\n", fname);
     }

     protected void check_source_target(boolean dotOne, String... args) {
         printargs("check_source_target", args);
         check_target(dotOne, args[0], args[1], args[2]);
         if (dotOne) {
             check_target(dotOne, args[0], "1." + args[1], args[2]);
         }
     }

     protected void check_target(boolean dotOne, String... args) {
         check(args[0], "-source " + args[1], "-target " + args[2]);
         if (dotOne) {
             check(args[0], "-source " + args[1], "-target 1." + args[2]);
         }
     }

     protected void check(String major, String... args) {
         printargs("check", args);
         List<String> jcargs = new ArrayList<>();
         jcargs.add("-Xlint:-options");

         // add in args conforming to List requrements of JavaCompiler
         for (String onearg : args) {
             String[] fields = onearg.split(" ");
             for (String onefield : fields) {
                 jcargs.add(onefield);
             }
         }

         boolean creturn = compile("Base.java", jcargs);
         if (!creturn) {
             // compilation errors note and return.. assume no class file
             System.err.println("check: Compilation Failed");
             System.err.println("\t classVersion:\t" + major);
             System.err.println("\t arguments:\t" + jcargs);
             failedCases++;

         } else if (!checkClassFileVersion("Base.class", major)) {
             failedCases++;
         }
     }

     protected void checksrc16(String... args) {
         printargs("checksrc16", args);
         int asize = args.length;
         String[] newargs = new String[asize + 1];
         System.arraycopy(args, 0, newargs, 0, asize);
         newargs[asize] = "Base.java";
         pass(newargs);
         newargs[asize] = "New17.java";
         fail(newargs);
     }

     protected void checksrc17(String... args) {
         printargs("checksrc17", args);
         int asize = args.length;
         String[] newargs = new String[asize+1];
         System.arraycopy(args, 0, newargs,0 , asize);
         newargs[asize] = "New17.java";
         pass(newargs);
         newargs[asize] = "New18.java";
         fail(newargs);
     }

     protected void checksrc18(String... args) {
         printargs("checksrc18", args);
         int asize = args.length;
         String[] newargs = new String[asize+1];
         System.arraycopy(args, 0, newargs,0 , asize);
         newargs[asize] = "New17.java";
         pass(newargs);
         newargs[asize] = "New18.java";
         pass(newargs);
         newargs[asize] = "New110.java";
         fail(newargs);
     }

     protected void checksrc19(String... args) {
         printargs("checksrc19", args);
         checksrc18(args);
     }

     protected void checksrc110(String... args) {
         printargs("checksrc110", args);
         int asize = args.length;
         String[] newargs = new String[asize+1];
         System.arraycopy(args, 0, newargs,0 , asize);
         newargs[asize] = "New17.java";
         pass(newargs);
         newargs[asize] = "New18.java";
         pass(newargs);
         newargs[asize] = "New110.java";
         pass(newargs);
     }

     protected void checksrc111(String... args) {
         printargs("checksrc111", args);
         checksrc110(args);
     }

     protected void pass(String... args) {
         printargs("pass", args);

         List<String> jcargs = new ArrayList<String>();
         jcargs.add("-Xlint:-options");

         // add in args conforming to List requrements of JavaCompiler
         for (String onearg : args) {
             String[] fields = onearg.split(" ");
             for (String onefield : fields) {
                 jcargs.add(onefield);
             }
         }

         // empty list is error
         if (jcargs.isEmpty()) {
             System.err.println("error: test error in pass() - No arguments");
             System.err.println("\t arguments:\t" + jcargs);
             failedCases++;
             return;
         }

         // the last argument is the filename *.java
         String filename = jcargs.get(jcargs.size() - 1);
         jcargs.remove(jcargs.size() - 1);

         boolean creturn = compile(filename, jcargs);
         // expect a compilation failure, failure if otherwise
         if (!creturn) {
             System.err.println("pass: Compilation erroneously failed");
             System.err.println("\t arguments:\t" + jcargs);
             System.err.println("\t file     :\t" + filename);
             failedCases++;

         }

     }

     protected void fail(String... args) {
         printargs("fail", args);

         List<String> jcargs = new ArrayList<String>();
         jcargs.add("-Xlint:-options");

         // add in args conforming to List requrements of JavaCompiler
         for (String onearg : args) {
             String[] fields = onearg.split(" ");
             for (String onefield : fields) {
                 jcargs.add(onefield);
             }
         }

         // empty list is error
         if (jcargs.isEmpty()) {
             System.err.println("error: test error in fail()- No arguments");
             System.err.println("\t arguments:\t" + jcargs);
             failedCases++;
             return;
         }

         // the last argument is the filename *.java
         String filename = jcargs.get(jcargs.size() - 1);
         jcargs.remove(jcargs.size() - 1);

         boolean creturn = compile(filename, jcargs);
         // expect a compilation failure, failure if otherwise
         if (creturn) {
             System.err.println("fail: Compilation erroneously succeeded");
             System.err.println("\t arguments:\t" + jcargs);
             System.err.println("\t file     :\t" + filename);
             failedCases++;
         }
     }

     protected boolean compile(String sourceFile, List<String>options) {
         JavaCompiler.CompilationTask jctask;
         try (StandardJavaFileManager fm = javacompiler.getStandardFileManager(null, null, null)) {
             Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(sourceFile);

             jctask = javacompiler.getTask(
                 null,    // Writer
                 fm,      // JavaFileManager
                 null,    // DiagnosticListener
                 options, // Iterable<String>
                 null,    // Iterable<String> classes
                 files);  // Iterable<? extends JavaFileObject>

             try {
                 return jctask.call();
             } catch (IllegalStateException e) {
                 System.err.println(e);
                 return false;
             }
         } catch (IOException e) {
             throw new Error(e);
         }
     }

     protected void writeSourceFile(String fileName, String body) throws IOException{
         try (Writer fw = new FileWriter(fileName)) {
             fw.write(body);
         }
     }

     protected void genSourceFiles() throws IOException{
         /* Create a file that executes with all supported versions. */
         writeSourceFile("Base.java","public class Base { }\n");

         /*
          * Create a file with a new feature in 1.7, not in 1.6 : "<>"
          */
         writeSourceFile("New17.java",
             "import java.util.List;\n" +
             "import java.util.ArrayList;\n" +
             "class New17 { List<String> s = new ArrayList<>(); }\n"
         );

         /*
          * Create a file with a new feature in 1.8, not in 1.7 : lambda
          */
         writeSourceFile("New18.java",
             "public class New18 { \n" +
             "    void m() { \n" +
             "    new Thread(() -> { }); \n" +
             "    } \n" +
             "} \n"
         );

         /*
          * Create a file with a new feature in 1.10, not in 1.9 : var
          */
         writeSourceFile("New110.java",
             "public class New110 { \n" +
             "    void m() { \n" +
             "    var tmp = new Thread(() -> { }); \n" +
             "    } \n" +
             "} \n"
         );

     }

     protected boolean checkClassFileVersion
         (String filename,String classVersionNumber) {
         ByteBuffer bb = ByteBuffer.allocate(1024);
         try (FileChannel fc = new FileInputStream(filename).getChannel()) {
             bb.clear();
             if (fc.read(bb) < 0)
                 throw new IOException("Could not read from file : " + filename);
             bb.flip();
             int minor = bb.getShort(4);
             int major = bb.getShort(6);
             String fileVersion = major + "." + minor;
             if (fileVersion.equals(classVersionNumber)) {
                 return true;
             } else {
                 System.err.println("checkClassFileVersion : Failed");
                 System.err.println("\tclassfile version mismatch");
                 System.err.println("\texpected : " + classVersionNumber);
                 System.err.println("\tfound    : " + fileVersion);
                 return false;
             }
         }
         catch (IOException e) {
             System.err.println("checkClassFileVersion : Failed");
             System.err.println("\terror :\t" + e.getMessage());
             System.err.println("\tfile:\tfilename");
         }
         return false;
     }
 }
	/*
	* Copyright (c) 2014, 2017, 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
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	* @test
	* @bug 4981566 5028634 5094412 6304984 7025786 7025789 8001112 8028545 8000961 8030610 8028546 8188870 8173382 8173382
	* @summary Check interpretation of -target and -source options
	* @modules java.compiler
	* jdk.compiler
	* @run main Versions
	*/

	import java.io.*;
	import java.nio.*;
	import java.nio.channels.*;

	import javax.tools.JavaCompiler;
	import javax.tools.ToolProvider;
	import javax.tools.JavaFileObject;
	import javax.tools.StandardJavaFileManager;
	import java.util.List;
	import java.util.ArrayList;
	import java.util.Arrays;


	public class Versions {

	protected JavaCompiler javacompiler;
	protected int failedCases;

	public Versions() throws IOException {
	javacompiler = ToolProvider.getSystemJavaCompiler();
	genSourceFiles();
	failedCases = 0;
	}

	public static void main(String... args) throws IOException {
	Versions versions = new Versions();
	versions.run();
	}

	void run() {

	String TC = "";
	System.out.println("Version.java: Starting");

	check("55.0");
	check("55.0", "-source 1.6");
	check("55.0", "-source 1.7");
	check("55.0", "-source 1.8");
	check("55.0", "-source 1.9");
	check("55.0", "-source 1.10");
	check("55.0", "-source 11");

	check_source_target(true, "50.0", "6", "6");
	check_source_target(true, "51.0", "6", "7");
	check_source_target(true, "51.0", "7", "7");
	check_source_target(true, "52.0", "6", "8");
	check_source_target(true, "52.0", "7", "8");
	check_source_target(true, "52.0", "8", "8");
	check_source_target(true, "53.0", "6", "9");
	check_source_target(true, "53.0", "7", "9");
	check_source_target(true, "53.0", "8", "9");
	check_source_target(true, "53.0", "9", "9");
	check_source_target(true, "54.0", "6", "10");
	check_source_target(true, "54.0", "7", "10");
	check_source_target(true, "54.0", "8", "10");
	check_source_target(true, "54.0", "9", "10");
	check_source_target(true, "54.0", "10", "10");
	check_source_target(false, "55.0", "6", "11");
	check_source_target(false, "55.0", "7", "11");
	check_source_target(false, "55.0", "8", "11");
	check_source_target(false, "55.0", "9", "11");
	check_source_target(false, "55.0", "10", "11");
	check_source_target(false, "55.0", "11", "11");

	checksrc16("-source 1.6");
	checksrc16("-source 6");
	checksrc16("-source 1.6", "-target 1.6");
	checksrc16("-source 6", "-target 6");
	checksrc17("-source 1.7");
	checksrc17("-source 7");
	checksrc17("-source 1.7", "-target 1.7");
	checksrc17("-source 7", "-target 7");
	checksrc18("-source 1.8");
	checksrc18("-source 8");
	checksrc18("-source 1.8", "-target 1.8");
	checksrc18("-source 8", "-target 8");
	checksrc19("-source 1.9");
	checksrc19("-source 9");
	checksrc19("-source 1.9", "-target 1.9");
	checksrc19("-source 9", "-target 9");
	checksrc110();
	checksrc110("-source 1.10");
	checksrc110("-source 10");
	checksrc110("-source 1.10", "-target 1.10");
	checksrc110("-source 10", "-target 10");
	checksrc111("-source 11");
	checksrc111("-source 11", "-target 11");
	checksrc111("-target 11");

	fail("-source 7", "-target 1.6", "Base.java");
	fail("-source 8", "-target 1.6", "Base.java");
	fail("-source 8", "-target 1.7", "Base.java");
	fail("-source 9", "-target 1.7", "Base.java");
	fail("-source 9", "-target 1.8", "Base.java");
	fail("-source 10", "-target 1.7", "Base.java");
	fail("-source 10", "-target 1.8", "Base.java");
	fail("-source 11", "-target 1.9", "Base.java");
	fail("-source 11", "-target 1.10", "Base.java");

	fail("-source 1.5", "-target 1.5", "Base.java");
	fail("-source 1.4", "-target 1.4", "Base.java");
	fail("-source 1.3", "-target 1.3", "Base.java");
	fail("-source 1.2", "-target 1.2", "Base.java");

	if (failedCases > 0) {
	System.err.println("failedCases = " + String.valueOf(failedCases));
	throw new Error("Test failed");
	}

	}

	protected void printargs(String fname,String... args) {
	System.out.printf("test: %s", fname);
	for (String onearg : args) {
	System.out.printf(" %s", onearg);
	}
	System.out.printf("\n", fname);
	}

	protected void check_source_target(boolean dotOne, String... args) {
	printargs("check_source_target", args);
	check_target(dotOne, args[0], args[1], args[2]);
	if (dotOne) {
	check_target(dotOne, args[0], "1." + args[1], args[2]);
	}
	}

	protected void check_target(boolean dotOne, String... args) {
	check(args[0], "-source " + args[1], "-target " + args[2]);
	if (dotOne) {
	check(args[0], "-source " + args[1], "-target 1." + args[2]);
	}
	}

	protected void check(String major, String... args) {
	printargs("check", args);
	List<String> jcargs = new ArrayList<>();
	jcargs.add("-Xlint:-options");

	// add in args conforming to List requrements of JavaCompiler
	for (String onearg : args) {
	String[] fields = onearg.split(" ");
	for (String onefield : fields) {
	jcargs.add(onefield);
	}
	}

	boolean creturn = compile("Base.java", jcargs);
	if (!creturn) {
	// compilation errors note and return.. assume no class file
	System.err.println("check: Compilation Failed");
	System.err.println("\t classVersion:\t" + major);
	System.err.println("\t arguments:\t" + jcargs);
	failedCases++;

	} else if (!checkClassFileVersion("Base.class", major)) {
	failedCases++;
	}
	}

	protected void checksrc16(String... args) {
	printargs("checksrc16", args);
	int asize = args.length;
	String[] newargs = new String[asize + 1];
	System.arraycopy(args, 0, newargs, 0, asize);
	newargs[asize] = "Base.java";
	pass(newargs);
	newargs[asize] = "New17.java";
	fail(newargs);
	}

	protected void checksrc17(String... args) {
	printargs("checksrc17", args);
	int asize = args.length;
	String[] newargs = new String[asize+1];
	System.arraycopy(args, 0, newargs,0 , asize);
	newargs[asize] = "New17.java";
	pass(newargs);
	newargs[asize] = "New18.java";
	fail(newargs);
	}

	protected void checksrc18(String... args) {
	printargs("checksrc18", args);
	int asize = args.length;
	String[] newargs = new String[asize+1];
	System.arraycopy(args, 0, newargs,0 , asize);
	newargs[asize] = "New17.java";
	pass(newargs);
	newargs[asize] = "New18.java";
	pass(newargs);
	newargs[asize] = "New110.java";
	fail(newargs);
	}

	protected void checksrc19(String... args) {
	printargs("checksrc19", args);
	checksrc18(args);
	}

	protected void checksrc110(String... args) {
	printargs("checksrc110", args);
	int asize = args.length;
	String[] newargs = new String[asize+1];
	System.arraycopy(args, 0, newargs,0 , asize);
	newargs[asize] = "New17.java";
	pass(newargs);
	newargs[asize] = "New18.java";
	pass(newargs);
	newargs[asize] = "New110.java";
	pass(newargs);
	}

	protected void checksrc111(String... args) {
	printargs("checksrc111", args);
	checksrc110(args);
	}

	protected void pass(String... args) {
	printargs("pass", args);

	List<String> jcargs = new ArrayList<String>();
	jcargs.add("-Xlint:-options");

	// add in args conforming to List requrements of JavaCompiler
	for (String onearg : args) {
	String[] fields = onearg.split(" ");
	for (String onefield : fields) {
	jcargs.add(onefield);
	}
	}

	// empty list is error
	if (jcargs.isEmpty()) {
	System.err.println("error: test error in pass() - No arguments");
	System.err.println("\t arguments:\t" + jcargs);
	failedCases++;
	return;
	}

	// the last argument is the filename *.java
	String filename = jcargs.get(jcargs.size() - 1);
	jcargs.remove(jcargs.size() - 1);

	boolean creturn = compile(filename, jcargs);
	// expect a compilation failure, failure if otherwise
	if (!creturn) {
	System.err.println("pass: Compilation erroneously failed");
	System.err.println("\t arguments:\t" + jcargs);
	System.err.println("\t file :\t" + filename);
	failedCases++;

	}

	}

	protected void fail(String... args) {
	printargs("fail", args);

	List<String> jcargs = new ArrayList<String>();
	jcargs.add("-Xlint:-options");

	// add in args conforming to List requrements of JavaCompiler
	for (String onearg : args) {
	String[] fields = onearg.split(" ");
	for (String onefield : fields) {
	jcargs.add(onefield);
	}
	}

	// empty list is error
	if (jcargs.isEmpty()) {
	System.err.println("error: test error in fail()- No arguments");
	System.err.println("\t arguments:\t" + jcargs);
	failedCases++;
	return;
	}

	// the last argument is the filename *.java
	String filename = jcargs.get(jcargs.size() - 1);
	jcargs.remove(jcargs.size() - 1);

	boolean creturn = compile(filename, jcargs);
	// expect a compilation failure, failure if otherwise
	if (creturn) {
	System.err.println("fail: Compilation erroneously succeeded");
	System.err.println("\t arguments:\t" + jcargs);
	System.err.println("\t file :\t" + filename);
	failedCases++;
	}
	}

	protected boolean compile(String sourceFile, List<String>options) {
	JavaCompiler.CompilationTask jctask;
	try (StandardJavaFileManager fm = javacompiler.getStandardFileManager(null, null, null)) {
	Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(sourceFile);

	jctask = javacompiler.getTask(
	null, // Writer
	fm, // JavaFileManager
	null, // DiagnosticListener
	options, // Iterable<String>
	null, // Iterable<String> classes
	files); // Iterable<? extends JavaFileObject>

	try {
	return jctask.call();
	} catch (IllegalStateException e) {
	System.err.println(e);
	return false;
	}
	} catch (IOException e) {
	throw new Error(e);
	}
	}

	protected void writeSourceFile(String fileName, String body) throws IOException{
	try (Writer fw = new FileWriter(fileName)) {
	fw.write(body);
	}
	}

	protected void genSourceFiles() throws IOException{
	/* Create a file that executes with all supported versions. */
	writeSourceFile("Base.java","public class Base { }\n");

	/*
	* Create a file with a new feature in 1.7, not in 1.6 : "<>"
	*/
	writeSourceFile("New17.java",
	"import java.util.List;\n" +
	"import java.util.ArrayList;\n" +
	"class New17 { List<String> s = new ArrayList<>(); }\n"
	);

	/*
	* Create a file with a new feature in 1.8, not in 1.7 : lambda
	*/
	writeSourceFile("New18.java",
	"public class New18 { \n" +
	" void m() { \n" +
	" new Thread(() -> { }); \n" +
	" } \n" +
	"} \n"
	);

	/*
	* Create a file with a new feature in 1.10, not in 1.9 : var
	*/
	writeSourceFile("New110.java",
	"public class New110 { \n" +
	" void m() { \n" +
	" var tmp = new Thread(() -> { }); \n" +
	" } \n" +
	"} \n"
	);

	}

	protected boolean checkClassFileVersion
	(String filename,String classVersionNumber) {
	ByteBuffer bb = ByteBuffer.allocate(1024);
	try (FileChannel fc = new FileInputStream(filename).getChannel()) {
	bb.clear();
	if (fc.read(bb) < 0)
	throw new IOException("Could not read from file : " + filename);
	bb.flip();
	int minor = bb.getShort(4);
	int major = bb.getShort(6);
	String fileVersion = major + "." + minor;
	if (fileVersion.equals(classVersionNumber)) {
	return true;
	} else {
	System.err.println("checkClassFileVersion : Failed");
	System.err.println("\tclassfile version mismatch");
	System.err.println("\texpected : " + classVersionNumber);
	System.err.println("\tfound : " + fileVersion);
	return false;
	}
	}
	catch (IOException e) {
	System.err.println("checkClassFileVersion : Failed");
	System.err.println("\terror :\t" + e.getMessage());
	System.err.println("\tfile:\tfilename");
	}
	return false;
	}
	}