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src/java.xml/share/classes/com/sun/org/apache/bcel/internal/util/BCELifier.java
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*** 19,271 ****
* limitations under the License.
*/
package com.sun.org.apache.bcel.internal.util;
! import com.sun.org.apache.bcel.internal.classfile.*;
! import com.sun.org.apache.bcel.internal.generic.*;
import com.sun.org.apache.bcel.internal.Repository;
! import com.sun.org.apache.bcel.internal.Constants;
! import java.io.*;
/**
* This class takes a given JavaClass object and converts it to a
* Java program that creates that very class using BCEL. This
* gives new users of BCEL a useful example showing how things
* are done with BCEL. It does not cover all features of BCEL,
* but tries to mimic hand-written code as close as possible.
*
! * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
*/
public class BCELifier extends com.sun.org.apache.bcel.internal.classfile.EmptyVisitor {
! private JavaClass _clazz;
! private PrintWriter _out;
! private ConstantPoolGen _cp;
/** @param clazz Java class to "decompile"
* @param out where to output Java program
*/
! public BCELifier(JavaClass clazz, OutputStream out) {
_clazz = clazz;
_out = new PrintWriter(out);
_cp = new ConstantPoolGen(_clazz.getConstantPool());
}
/** Start Java code generation
*/
public void start() {
visitJavaClass(_clazz);
_out.flush();
}
! public void visitJavaClass(JavaClass clazz) {
String class_name = clazz.getClassName();
! String super_name = clazz.getSuperclassName();
! String package_name = clazz.getPackageName();
! String inter = Utility.printArray(clazz.getInterfaceNames(),
! false, true);
! if(!"".equals(package_name)) {
class_name = class_name.substring(package_name.length() + 1);
! _out.println("package " + package_name + ";\n");
}
!
! _out.println("import com.sun.org.apache.bcel.internal.generic.*;");
! _out.println("import com.sun.org.apache.bcel.internal.classfile.*;");
! _out.println("import com.sun.org.apache.bcel.internal.*;");
! _out.println("import java.io.*;\n");
!
! _out.println("public class " + class_name + "Creator implements Constants {");
_out.println(" private InstructionFactory _factory;");
_out.println(" private ConstantPoolGen _cp;");
! _out.println(" private ClassGen _cg;\n");
!
_out.println(" public " + class_name + "Creator() {");
! _out.println(" _cg = new ClassGen(\"" +
! (("".equals(package_name))? class_name :
! package_name + "." + class_name) +
! "\", \"" + super_name + "\", " +
! "\"" + clazz.getSourceFileName() + "\", " +
! printFlags(clazz.getAccessFlags(), true) + ", " +
! "new String[] { " + inter + " });\n");
!
_out.println(" _cp = _cg.getConstantPool();");
_out.println(" _factory = new InstructionFactory(_cg, _cp);");
! _out.println(" }\n");
!
printCreate();
!
! Field[] fields = clazz.getFields();
!
! if(fields.length > 0) {
_out.println(" private void createFields() {");
_out.println(" FieldGen field;");
!
! for(int i=0; i < fields.length; i++) {
! fields[i].accept(this);
}
!
! _out.println(" }\n");
}
!
! Method[] methods = clazz.getMethods();
!
! for(int i=0; i < methods.length; i++) {
_out.println(" private void createMethod_" + i + "() {");
-
methods[i].accept(this);
! _out.println(" }\n");
}
-
printMain();
_out.println("}");
}
private void printCreate() {
_out.println(" public void create(OutputStream out) throws IOException {");
!
! Field[] fields = _clazz.getFields();
! if(fields.length > 0) {
_out.println(" createFields();");
}
!
! Method[] methods = _clazz.getMethods();
! for(int i=0; i < methods.length; i++) {
_out.println(" createMethod_" + i + "();");
}
-
_out.println(" _cg.getJavaClass().dump(out);");
!
! _out.println(" }\n");
}
- private void printMain() {
- String class_name = _clazz.getClassName();
! _out.println(" public static void _main(String[] args) throws Exception {");
! _out.println(" " + class_name + "Creator creator = new " +
! class_name + "Creator();");
! _out.println(" creator.create(new FileOutputStream(\"" + class_name +
! ".class\"));");
_out.println(" }");
}
- public void visitField(Field field) {
- _out.println("\n field = new FieldGen(" +
- printFlags(field.getAccessFlags()) +
- ", " + printType(field.getSignature()) + ", \"" +
- field.getName() + "\", _cp);");
! ConstantValue cv = field.getConstantValue();
!
! if(cv != null) {
! String value = cv.toString();
_out.println(" field.setInitValue(" + value + ")");
}
-
_out.println(" _cg.addField(field.getField());");
}
- public void visitMethod(Method method) {
- MethodGen mg = new MethodGen(method, _clazz.getClassName(), _cp);
-
- Type result_type = mg.getReturnType();
- Type[] arg_types = mg.getArgumentTypes();
_out.println(" InstructionList il = new InstructionList();");
! _out.println(" MethodGen method = new MethodGen(" +
! printFlags(method.getAccessFlags()) +
! ", " + printType(result_type) +
! ", " + printArgumentTypes(arg_types) + ", " +
! "new String[] { " +
! Utility.printArray(mg.getArgumentNames(), false, true) +
! " }, \"" + method.getName() + "\", \"" +
! _clazz.getClassName() + "\", il, _cp);\n");
!
! BCELFactory factory = new BCELFactory(mg, _out);
factory.start();
-
_out.println(" method.setMaxStack();");
_out.println(" method.setMaxLocals();");
_out.println(" _cg.addMethod(method.getMethod());");
_out.println(" il.dispose();");
}
! static String printFlags(int flags) {
! return printFlags(flags, false);
}
! static String printFlags(int flags, boolean for_class) {
! if(flags == 0)
return "0";
-
- StringBuffer buf = new StringBuffer();
- for(int i=0, pow=1; i <= Constants.MAX_ACC_FLAG; i++) {
- if((flags & pow) != 0) {
- if((pow == Constants.ACC_SYNCHRONIZED) && for_class)
- buf.append("ACC_SUPER | ");
- else
- buf.append("ACC_" + Constants.ACCESS_NAMES[i].toUpperCase() + " | ");
}
!
pow <<= 1;
}
!
! String str = buf.toString();
return str.substring(0, str.length() - 3);
}
- static String printArgumentTypes(Type[] arg_types) {
- if(arg_types.length == 0)
- return "Type.NO_ARGS";
-
- StringBuffer args = new StringBuffer();
! for(int i=0; i < arg_types.length; i++) {
args.append(printType(arg_types[i]));
!
! if(i < arg_types.length - 1)
args.append(", ");
}
!
return "new Type[] { " + args.toString() + " }";
}
! static String printType(Type type) {
return printType(type.getSignature());
}
! static String printType(String signature) {
! Type type = Type.getType(signature);
! byte t = type.getType();
!
! if(t <= Constants.T_VOID) {
! return "Type." + Constants.TYPE_NAMES[t].toUpperCase();
! } else if(type.toString().equals("java.lang.String")) {
return "Type.STRING";
! } else if(type.toString().equals("java.lang.Object")) {
return "Type.OBJECT";
! } else if(type.toString().equals("java.lang.StringBuffer")) {
return "Type.STRINGBUFFER";
! } else if(type instanceof ArrayType) {
! ArrayType at = (ArrayType)type;
!
! return "new ArrayType(" + printType(at.getBasicType()) +
! ", " + at.getDimensions() + ")";
} else {
! return "new ObjectType(\"" + Utility.signatureToString(signature, false) +
! "\")";
}
}
! /** Default _main method
*/
! public static void _main(String[] argv) throws Exception {
! JavaClass java_class;
! String name = argv[0];
- if((java_class = Repository.lookupClass(name)) == null)
- java_class = new ClassParser(name).parse(); // May throw IOException
! BCELifier bcelifier = new BCELifier(java_class, System.out);
! bcelifier.start();
}
}
--- 19,307 ----
* limitations under the License.
*/
package com.sun.org.apache.bcel.internal.util;
! import java.io.IOException;
! import java.io.OutputStream;
! import java.io.PrintWriter;
! import java.util.Locale;
!
! import com.sun.org.apache.bcel.internal.Const;
import com.sun.org.apache.bcel.internal.Repository;
! import com.sun.org.apache.bcel.internal.classfile.ClassParser;
! import com.sun.org.apache.bcel.internal.classfile.ConstantValue;
! import com.sun.org.apache.bcel.internal.classfile.Field;
! import com.sun.org.apache.bcel.internal.classfile.JavaClass;
! import com.sun.org.apache.bcel.internal.classfile.Method;
! import com.sun.org.apache.bcel.internal.classfile.Utility;
! import com.sun.org.apache.bcel.internal.generic.ArrayType;
! import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
! import com.sun.org.apache.bcel.internal.generic.MethodGen;
! import com.sun.org.apache.bcel.internal.generic.Type;
/**
* This class takes a given JavaClass object and converts it to a
* Java program that creates that very class using BCEL. This
* gives new users of BCEL a useful example showing how things
* are done with BCEL. It does not cover all features of BCEL,
* but tries to mimic hand-written code as close as possible.
*
! * @version $Id: BCELifier.java 1750228 2016-06-25 21:47:44Z ggregory $
*/
public class BCELifier extends com.sun.org.apache.bcel.internal.classfile.EmptyVisitor {
!
! /**
! * Enum corresponding to flag source.
! */
! public enum FLAGS {
! UNKNOWN,
! CLASS,
! METHOD,
! }
!
! // The base package name for imports; assumes Const is at the top level
! // N.B we use the class so renames will be detected by the compiler/IDE
! private static final String BASE_PACKAGE = Const.class.getPackage().getName();
! private static final String CONSTANT_PREFIX = Const.class.getSimpleName()+".";
!
! private final JavaClass _clazz;
! private final PrintWriter _out;
! private final ConstantPoolGen _cp;
/** @param clazz Java class to "decompile"
* @param out where to output Java program
*/
! public BCELifier(final JavaClass clazz, final OutputStream out) {
_clazz = clazz;
_out = new PrintWriter(out);
_cp = new ConstantPoolGen(_clazz.getConstantPool());
}
+
/** Start Java code generation
*/
public void start() {
visitJavaClass(_clazz);
_out.flush();
}
!
! @Override
! public void visitJavaClass( final JavaClass clazz ) {
String class_name = clazz.getClassName();
! final String super_name = clazz.getSuperclassName();
! final String package_name = clazz.getPackageName();
! final String inter = Utility.printArray(clazz.getInterfaceNames(), false, true);
! if (!"".equals(package_name)) {
class_name = class_name.substring(package_name.length() + 1);
! _out.println("package " + package_name + ";");
! _out.println();
}
! _out.println("import " + BASE_PACKAGE + ".generic.*;");
! _out.println("import " + BASE_PACKAGE + ".classfile.*;");
! _out.println("import " + BASE_PACKAGE + ".*;");
! _out.println("import java.io.*;");
! _out.println();
! _out.println("public class " + class_name + "Creator {");
_out.println(" private InstructionFactory _factory;");
_out.println(" private ConstantPoolGen _cp;");
! _out.println(" private ClassGen _cg;");
! _out.println();
_out.println(" public " + class_name + "Creator() {");
! _out.println(" _cg = new ClassGen(\""
! + (("".equals(package_name)) ? class_name : package_name + "." + class_name)
! + "\", \"" + super_name + "\", " + "\"" + clazz.getSourceFileName() + "\", "
! + printFlags(clazz.getAccessFlags(), FLAGS.CLASS) + ", "
! + "new String[] { " + inter + " });");
! _out.println();
_out.println(" _cp = _cg.getConstantPool();");
_out.println(" _factory = new InstructionFactory(_cg, _cp);");
! _out.println(" }");
! _out.println();
printCreate();
! final Field[] fields = clazz.getFields();
! if (fields.length > 0) {
_out.println(" private void createFields() {");
_out.println(" FieldGen field;");
! for (final Field field : fields) {
! field.accept(this);
}
! _out.println(" }");
! _out.println();
}
! final Method[] methods = clazz.getMethods();
! for (int i = 0; i < methods.length; i++) {
_out.println(" private void createMethod_" + i + "() {");
methods[i].accept(this);
! _out.println(" }");
! _out.println();
}
printMain();
_out.println("}");
}
+
private void printCreate() {
_out.println(" public void create(OutputStream out) throws IOException {");
! final Field[] fields = _clazz.getFields();
! if (fields.length > 0) {
_out.println(" createFields();");
}
! final Method[] methods = _clazz.getMethods();
! for (int i = 0; i < methods.length; i++) {
_out.println(" createMethod_" + i + "();");
}
_out.println(" _cg.getJavaClass().dump(out);");
! _out.println(" }");
! _out.println();
}
! private void printMain() {
! final String class_name = _clazz.getClassName();
! _out.println(" public static void main(String[] args) throws Exception {");
! _out.println(" " + class_name + "Creator creator = new " + class_name + "Creator();");
! _out.println(" creator.create(new FileOutputStream(\"" + class_name + ".class\"));");
_out.println(" }");
}
! @Override
! public void visitField( final Field field ) {
! _out.println();
! _out.println(" field = new FieldGen(" + printFlags(field.getAccessFlags()) + ", "
! + printType(field.getSignature()) + ", \"" + field.getName() + "\", _cp);");
! final ConstantValue cv = field.getConstantValue();
! if (cv != null) {
! final String value = cv.toString();
_out.println(" field.setInitValue(" + value + ")");
}
_out.println(" _cg.addField(field.getField());");
}
+ @Override
+ public void visitMethod( final Method method ) {
+ final MethodGen mg = new MethodGen(method, _clazz.getClassName(), _cp);
_out.println(" InstructionList il = new InstructionList();");
! _out.println(" MethodGen method = new MethodGen("
! + printFlags(method.getAccessFlags(), FLAGS.METHOD) + ", "
! + printType(mg.getReturnType()) + ", "
! + printArgumentTypes(mg.getArgumentTypes()) + ", "
! + "new String[] { " + Utility.printArray(mg.getArgumentNames(), false, true)
! + " }, \"" + method.getName() + "\", \"" + _clazz.getClassName() + "\", il, _cp);");
! _out.println();
! final BCELFactory factory = new BCELFactory(mg, _out);
factory.start();
_out.println(" method.setMaxStack();");
_out.println(" method.setMaxLocals();");
_out.println(" _cg.addMethod(method.getMethod());");
_out.println(" il.dispose();");
}
!
! static String printFlags( final int flags ) {
! return printFlags(flags, FLAGS.UNKNOWN);
}
! /**
! * Return a string with the flag settings
! * @param flags the flags field to interpret
! * @param location the item type
! * @return the formatted string
! * @since 6.0 made public
! */
! public static String printFlags( final int flags, final FLAGS location ) {
! if (flags == 0) {
return "0";
}
! final StringBuilder buf = new StringBuilder();
! for (int i = 0, pow = 1; pow <= Const.MAX_ACC_FLAG; i++) {
! if ((flags & pow) != 0) {
! if ((pow == Const.ACC_SYNCHRONIZED) && (location == FLAGS.CLASS)) {
! buf.append(CONSTANT_PREFIX+"ACC_SUPER | ");
! } else if ((pow == Const.ACC_VOLATILE) && (location == FLAGS.METHOD)) {
! buf.append(CONSTANT_PREFIX+"ACC_BRIDGE | ");
! } else if ((pow == Const.ACC_TRANSIENT) && (location == FLAGS.METHOD)) {
! buf.append(CONSTANT_PREFIX+"ACC_VARARGS | ");
! } else {
! if (i < Const.ACCESS_NAMES_LENGTH) {
! buf.append(CONSTANT_PREFIX+"ACC_")
! .append(Const.getAccessName(i).toUpperCase(Locale.ENGLISH))
! .append( " | ");
! } else {
! buf.append(String.format (CONSTANT_PREFIX+"ACC_BIT %x | ", pow));
! }
! }
! }
pow <<= 1;
}
! final String str = buf.toString();
return str.substring(0, str.length() - 3);
}
! static String printArgumentTypes( final Type[] arg_types ) {
! if (arg_types.length == 0) {
! return "Type.NO_ARGS";
! }
! final StringBuilder args = new StringBuilder();
! for (int i = 0; i < arg_types.length; i++) {
args.append(printType(arg_types[i]));
! if (i < arg_types.length - 1) {
args.append(", ");
}
! }
return "new Type[] { " + args.toString() + " }";
}
!
! static String printType( final Type type ) {
return printType(type.getSignature());
}
!
! static String printType( final String signature ) {
! final Type type = Type.getType(signature);
! final byte t = type.getType();
! if (t <= Const.T_VOID) {
! return "Type." + Const.getTypeName(t).toUpperCase(Locale.ENGLISH);
! } else if (type.toString().equals("java.lang.String")) {
return "Type.STRING";
! } else if (type.toString().equals("java.lang.Object")) {
return "Type.OBJECT";
! } else if (type.toString().equals("java.lang.StringBuffer")) {
return "Type.STRINGBUFFER";
! } else if (type instanceof ArrayType) {
! final ArrayType at = (ArrayType) type;
! return "new ArrayType(" + printType(at.getBasicType()) + ", " + at.getDimensions()
! + ")";
} else {
! return "new ObjectType(\"" + Utility.signatureToString(signature, false) + "\")";
}
}
!
! /** Default main method
*/
! public static void _main( final String[] argv ) throws Exception {
! if (argv.length != 1) {
! System.out.println("Usage: BCELifier classname");
! System.out.println("\tThe class must exist on the classpath");
! return;
! }
! final JavaClass java_class = getJavaClass(argv[0]);
! final BCELifier bcelifier = new BCELifier(java_class, System.out);
! bcelifier.start();
! }
! // Needs to be accessible from unit test code
! static JavaClass getJavaClass(final String name) throws ClassNotFoundException, IOException {
! JavaClass java_class;
! if ((java_class = Repository.lookupClass(name)) == null) {
! java_class = new ClassParser(name).parse(); // May throw IOException
! }
! return java_class;
}
}
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