mockit.external.asm.ClassReader Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jmockit Show documentation
Show all versions of jmockit Show documentation
JMockit is a Java toolkit for automated developer testing.
It contains APIs for the creation of the objects to be tested, for mocking dependencies, and for faking external
APIs; JUnit (4 & 5) and TestNG test runners are supported.
It also contains an advanced code coverage tool.
/*
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2011 INRIA, France Telecom
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package mockit.external.asm;
import java.io.*;
import javax.annotation.*;
/**
* A Java class parser to make a {@link ClassVisitor} visit an existing class.
* This class parses a byte array conforming to the Java class file format and calls the appropriate visit methods of a
* given class visitor for each field, method and bytecode instruction encountered.
*/
public final class ClassReader extends AnnotatedReader
{
public interface Flags
{
/**
* Flag to skip method code. If this class is set CODE attribute won't be visited.
* This can be used, for example, to retrieve annotations for methods and method parameters.
*/
int SKIP_CODE = 1;
/**
* Flag to skip the debug information in the class. If this flag is set the debug information of the class is not
* visited, i.e. the {@link MethodVisitor#visitLocalVariable} and {@link MethodVisitor#visitLineNumber} methods
* will not be called.
*/
int SKIP_DEBUG = 2;
int SKIP_CODE_DEBUG = SKIP_CODE + SKIP_DEBUG;
int SKIP_INNER_CLASSES = 4;
}
private static final String[] NO_INTERFACES = {};
/**
* Start index of the class header information (access, name...) in {@link #code}.
*/
@Nonnegative final int header;
ClassVisitor cv;
@Nonnegative int flags;
@Nonnull private String[] interfaces = NO_INTERFACES;
@Nullable private String sourceFileName;
@Nullable private EnclosingMethod enclosingMethod;
@Nonnegative private int innerClassesCodeIndex;
@Nonnegative private int attributesCodeIndex;
/**
* The start index of each bootstrap method.
*/
@Nullable int[] bootstrapMethods;
/**
* Initializes a new class reader with the given bytecode array for a classfile.
*/
public ClassReader(@Nonnull byte[] code) {
super(code);
header = codeIndex; // the class header information starts just after the constant pool
}
/**
* Initializes a new class reader whose classfile bytecode array is read from the given input stream.
*/
public ClassReader(@Nonnull InputStream is) throws IOException {
this(readClass(is));
}
@Nonnull
private static byte[] readClass(@Nonnull InputStream is) throws IOException {
try {
byte[] b = new byte[is.available()];
int len = 0;
while (true) {
int n = is.read(b, len, b.length - len);
if (n == -1) {
if (len < b.length) {
byte[] c = new byte[len];
System.arraycopy(b, 0, c, 0, len);
b = c;
}
return b;
}
len += n;
if (len == b.length) {
int last = is.read();
if (last < 0) {
return b;
}
byte[] c = new byte[b.length + 1000];
System.arraycopy(b, 0, c, 0, len);
c[len++] = (byte) last;
b = c;
}
}
}
finally {
is.close();
}
}
/**
* Returns the classfile version of the class being read (see {@link ClassVersion}).
*/
public int getVersion() {
codeIndex = 6;
return readShort();
}
/**
* Returns the class's access flags (see {@link Access}).
*/
public int getAccess() {
codeIndex = header;
return readUnsignedShort();
}
/**
* Returns the internal of name of the super class. For interfaces, the super class is {@link Object}.
*/
@Nonnull
public String getSuperName() {
codeIndex = header + 4;
return readNonnullClass();
}
/**
* Returns the bytecode array of the Java classfile that was read.
*/
@Nonnull
public byte[] getBytecode() { return code; }
/**
* Makes the given visitor visit the Java class of this Class Reader, all attributes included.
*/
public void accept(ClassVisitor cv) {
accept(cv, 0);
}
/**
* Makes the given visitor visit the Java class of this Class Reader.
*
* @param cv the visitor that must visit this class.
* @param flags option flags that can be used to modify the default behavior of this class. See {@link Flags}.
*/
public void accept(@Nonnull ClassVisitor cv, @Nonnegative int flags) {
this.cv = cv;
this.flags = flags;
int version = getVersion();
codeIndex = header;
access = readUnsignedShort();
String classDesc = readNonnullClass();
String superClassDesc = readClass();
readInterfaces();
readClassAttributes();
cv.visit(version, access, classDesc, signature, superClassDesc, interfaces);
visitSourceFileName();
visitOuterClass();
readAnnotations(cv);
readInnerClasses();
readFieldsAndMethods();
cv.visitEnd();
}
private void readInterfaces() {
int interfaceCount = readUnsignedShort();
if (interfaceCount > 0) {
interfaces = new String[interfaceCount];
for (int i = 0; i < interfaceCount; i++) {
interfaces[i] = readNonnullClass();
}
}
}
private void readClassAttributes() {
sourceFileName = null;
enclosingMethod = null;
innerClassesCodeIndex = 0;
codeIndex = getAttributesStartIndex();
readAttributes();
}
@Nullable @Override
Boolean readAttribute(@Nonnull String attributeName) {
if ("SourceFile".equals(attributeName)) {
sourceFileName = readNonnullUTF8();
return true;
}
if ("EnclosingMethod".equals(attributeName)) {
enclosingMethod = new EnclosingMethod(this);
return true;
}
if ("BootstrapMethods".equals(attributeName)) {
readBootstrapMethods();
return true;
}
if ("InnerClasses".equals(attributeName)) {
if ((flags & Flags.SKIP_INNER_CLASSES) == 0) {
innerClassesCodeIndex = codeIndex;
}
return false;
}
return null;
}
private void readBootstrapMethods() {
int bsmCount = readUnsignedShort();
bootstrapMethods = new int[bsmCount];
for (int i = 0; i < bsmCount; i++) {
bootstrapMethods[i] = codeIndex;
codeIndex += 2;
int codeOffset = readUnsignedShort();
codeIndex += codeOffset << 1;
}
}
private void visitSourceFileName() {
if ((flags & Flags.SKIP_DEBUG) == 0) {
cv.visitSource(sourceFileName);
}
}
private void visitOuterClass() {
if (enclosingMethod != null) {
cv.visitOuterClass(enclosingMethod.owner, enclosingMethod.name, enclosingMethod.desc);
}
}
private void readInnerClasses() {
int startIndex = innerClassesCodeIndex;
if (startIndex != 0) {
codeIndex = startIndex;
for (int innerClassCount = readUnsignedShort(); innerClassCount > 0; innerClassCount--) {
String name = readNonnullClass();
String outerName = readClass();
String innerName = readUTF8();
int access = readUnsignedShort();
cv.visitInnerClass(name, outerName, innerName, access);
}
}
}
private void readFieldsAndMethods() {
codeIndex = getCodeIndexAfterInterfaces(interfaces.length);
FieldReader fieldReader = new FieldReader(this);
codeIndex = fieldReader.readFields();
MethodReader methodReader = new MethodReader(this);
codeIndex = methodReader.readMethods();
}
@Nonnegative
private int getCodeIndexAfterInterfaces(@Nonnegative int interfaceCount) { return header + 8 + 2 * interfaceCount; }
/**
* Returns the start index of the attribute_info structure of this class.
*/
@Nonnegative
private int getAttributesStartIndex() {
if (attributesCodeIndex == 0) {
skipHeader();
skipClassMembers(); // fields
skipClassMembers(); // methods
attributesCodeIndex = codeIndex;
}
return attributesCodeIndex;
}
private void skipHeader() {
int interfaceCount = readUnsignedShort(header + 6);
codeIndex = getCodeIndexAfterInterfaces(interfaceCount);
}
private void skipClassMembers() {
for (int memberCount = readUnsignedShort(); memberCount > 0; memberCount--) {
codeIndex += 6; // skips access, name and desc
skipMemberAttributes();
}
}
private void skipMemberAttributes() {
for (int attributeCount = readUnsignedShort(); attributeCount > 0; attributeCount--) {
codeIndex += 2; // skips attribute name
int codeOffsetToNextAttribute = readInt();
codeIndex += codeOffsetToNextAttribute;
}
}
boolean positionAtBootstrapMethodsAttribute() {
codeIndex = getAttributesStartIndex();
for (int attributeCount = readUnsignedShort(); attributeCount > 0; attributeCount--) {
String attrName = readNonnullUTF8();
if ("BootstrapMethods".equals(attrName)) {
return true;
}
int codeOffsetToNextAttribute = readInt();
codeIndex += codeOffsetToNextAttribute;
}
return false;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy