scouter.org.objectweb.asm.util.CheckClassAdapter Maven / Gradle / Ivy
// 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 scouter.org.objectweb.asm.util;
import scouter.org.objectweb.asm.AnnotationVisitor;
import scouter.org.objectweb.asm.Attribute;
import scouter.org.objectweb.asm.ClassReader;
import scouter.org.objectweb.asm.ClassVisitor;
import scouter.org.objectweb.asm.FieldVisitor;
import scouter.org.objectweb.asm.Label;
import scouter.org.objectweb.asm.MethodVisitor;
import scouter.org.objectweb.asm.ModuleVisitor;
import scouter.org.objectweb.asm.Opcodes;
import scouter.org.objectweb.asm.Type;
import scouter.org.objectweb.asm.TypePath;
import scouter.org.objectweb.asm.TypeReference;
import scouter.org.objectweb.asm.tree.ClassNode;
import scouter.org.objectweb.asm.tree.MethodNode;
import scouter.org.objectweb.asm.tree.TryCatchBlockNode;
import scouter.org.objectweb.asm.tree.analysis.Analyzer;
import scouter.org.objectweb.asm.tree.analysis.BasicValue;
import scouter.org.objectweb.asm.tree.analysis.Frame;
import scouter.org.objectweb.asm.tree.analysis.SimpleVerifier;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* A {@link ClassVisitor} that checks that its methods are properly used. More precisely this class
* adapter checks each method call individually, based only on its arguments, but does
* not check the sequence of method calls. For example, the invalid sequence
* visitField(ACC_PUBLIC, "i", "I", null) visitField(ACC_PUBLIC, "i", "D", null)
* will not be detected by this class adapter.
*
* CheckClassAdapter can be also used to verify bytecode transformations in order to
* make sure that the transformed bytecode is sane. For example:
*
*
* InputStream inputStream = ...; // get bytes for the source class
* ClassReader classReader = new ClassReader(inputStream);
* ClassWriter classWriter = new ClassWriter(classReader, ClassWriter.COMPUTE_MAXS);
* ClassVisitor classVisitor = new MyClassAdapter(new CheckClassAdapter(classWriter, true));
* classReader.accept(classVisitor, 0);
*
* StringWriter stringWriter = new StringWriter();
* PrintWriter printWriter = new PrintWriter(stringWriter);
* CheckClassAdapter.verify(new ClassReader(classWriter.toByteArray()), false, printWriter);
* assertTrue(stringWriter.toString().isEmpty());
*
*
* The above code pass the transformed bytecode through a CheckClassAdapter, with data
* flow checks enabled. These checks are not exactly the same as the JVM verification, but provide
* some basic type checking for each method instruction. If the bytecode has errors, the output text
* shows the erroneous instruction number, and a dump of the failed method with information about
* the type of the local variables and of the operand stack slots for each instruction. For example
* (format is - insnNumber locals : stack):
*
*
* org.objectweb.asm.tree.analysis.AnalyzerException: Error at instruction 71: Expected I, but found .
* at org.objectweb.asm.tree.analysis.Analyzer.analyze(Analyzer.java:...)
* at org.objectweb.asm.util.CheckClassAdapter.verify(CheckClassAdapter.java:...)
* ...
* remove()V
* 00000 LinkedBlockingQueue$Itr . . . . . . . . : ICONST_0
* 00001 LinkedBlockingQueue$Itr . . . . . . . . : I ISTORE 2
* 00001 LinkedBlockingQueue$Itr . I . . . . . . :
* ...
* 00071 LinkedBlockingQueue$Itr . I . . . . . . : ILOAD 1
* 00072 ? INVOKESPECIAL java/lang/Integer.<init> (I)V
* ...
*
*
* The above output shows that the local variable 1, loaded by the ILOAD 1 instruction
* at position 00071 is not initialized, whereas the local variable 2 is initialized
* and contains an int value.
*
* @author Eric Bruneton
*/
public class CheckClassAdapter extends ClassVisitor {
private static final String ERROR_AT = ": error at index ";
/** Whether the bytecode must be checked with a BasicVerifier. */
private boolean checkDataFlow;
/** The class version number. */
private int version;
/** Whether the {@link #visit} method has been called. */
private boolean visitCalled;
/** Whether the {@link #visitModule} method has been called. */
private boolean visitModuleCalled;
/** Whether the {@link #visitSource} method has been called. */
private boolean visitSourceCalled;
/** Whether the {@link #visitOuterClass} method has been called. */
private boolean visitOuterClassCalled;
/** Whether the {@link #visitNestHostExperimental} method has been called. */
private boolean visitNestHostCalled;
/**
* The common package of all the nest members. Not null if the visitNestMember method has
* been called.
*/
private String nestMemberPackageName;
/** Whether the {@link #visitEnd} method has been called. */
private boolean visitEndCalled;
/** The index of the instruction designated by each visited label so far. */
private Map labelInsnIndices;
// -----------------------------------------------------------------------------------------------
// Static verification methods
// -----------------------------------------------------------------------------------------------
/**
* Checks the given class.
*
* Usage: CheckClassAdapter <binary class name or class file name>
*
* @param args the command line arguments.
* @throws IOException if the class cannot be found, or if an IO exception occurs.
*/
public static void main(final String[] args) throws IOException {
if (args.length != 1) {
System.err.println(
"Verifies the given class.\n"
+ "Usage: CheckClassAdapter ");
return;
}
ClassReader classReader;
if (args[0].endsWith(".class")) {
classReader = new ClassReader(new FileInputStream(args[0]));
} else {
classReader = new ClassReader(args[0]);
}
verify(classReader, false, new PrintWriter(System.err));
}
/**
* Checks the given class.
*
* @param classReader the class to be checked.
* @param printResults whether to print the results of the bytecode verification.
* @param printWriter where the results (or the stack trace in case of error) must be printed.
*/
public static void verify(
final ClassReader classReader, final boolean printResults, final PrintWriter printWriter) {
verify(classReader, null, printResults, printWriter);
}
/**
* Checks the given class.
*
* @param classReader the class to be checked.
* @param loader a ClassLoader which will be used to load referenced classes. May be
* null.
* @param printResults whether to print the results of the bytecode verification.
* @param printWriter where the results (or the stack trace in case of error) must be printed.
*/
public static void verify(
final ClassReader classReader,
final ClassLoader loader,
final boolean printResults,
final PrintWriter printWriter) {
ClassNode classNode = new ClassNode();
classReader.accept(
new CheckClassAdapter(Opcodes.ASM7_EXPERIMENTAL, classNode, false) {},
ClassReader.SKIP_DEBUG);
Type syperType = classNode.superName == null ? null : Type.getObjectType(classNode.superName);
List methods = classNode.methods;
List interfaces = new ArrayList();
for (String interfaceName : classNode.interfaces) {
interfaces.add(Type.getObjectType(interfaceName));
}
for (MethodNode method : methods) {
SimpleVerifier verifier =
new SimpleVerifier(
Type.getObjectType(classNode.name),
syperType,
interfaces,
(classNode.access & Opcodes.ACC_INTERFACE) != 0);
Analyzer analyzer = new Analyzer(verifier);
if (loader != null) {
verifier.setClassLoader(loader);
}
try {
analyzer.analyze(classNode.name, method);
} catch (Exception e) {
e.printStackTrace(printWriter);
}
if (printResults) {
printAnalyzerResult(method, analyzer, printWriter);
}
}
printWriter.flush();
}
static void printAnalyzerResult(
final MethodNode method, final Analyzer analyzer, final PrintWriter printWriter) {
Textifier textifier = new Textifier();
TraceMethodVisitor traceMethodVisitor = new TraceMethodVisitor(textifier);
printWriter.println(method.name + method.desc);
for (int i = 0; i < method.instructions.size(); ++i) {
method.instructions.get(i).accept(traceMethodVisitor);
StringBuilder stringBuilder = new StringBuilder();
Frame frame = analyzer.getFrames()[i];
if (frame == null) {
stringBuilder.append('?');
} else {
for (int j = 0; j < frame.getLocals(); ++j) {
stringBuilder.append(getUnqualifiedName(frame.getLocal(j).toString())).append(' ');
}
stringBuilder.append(" : ");
for (int j = 0; j < frame.getStackSize(); ++j) {
stringBuilder.append(getUnqualifiedName(frame.getStack(j).toString())).append(' ');
}
}
while (stringBuilder.length() < method.maxStack + method.maxLocals + 1) {
stringBuilder.append(' ');
}
printWriter.print(Integer.toString(i + 100000).substring(1));
printWriter.print(
" " + stringBuilder + " : " + textifier.text.get(textifier.text.size() - 1));
}
for (TryCatchBlockNode tryCatchBlock : method.tryCatchBlocks) {
tryCatchBlock.accept(traceMethodVisitor);
printWriter.print(" " + textifier.text.get(textifier.text.size() - 1));
}
printWriter.println();
}
private static String getUnqualifiedName(final String name) {
int lastSlashIndex = name.lastIndexOf('/');
if (lastSlashIndex == -1) {
return name;
} else {
int endIndex = name.length();
if (name.charAt(endIndex - 1) == ';') {
endIndex--;
}
return name.substring(lastSlashIndex + 1, endIndex);
}
}
// -----------------------------------------------------------------------------------------------
// Constructors
// -----------------------------------------------------------------------------------------------
/**
* Constructs a new {@link CheckClassAdapter}. Subclasses must not use this constructor.
* Instead, they must use the {@link #CheckClassAdapter(int, ClassVisitor, boolean)} version.
*
* @param classVisitor the class visitor to which this adapter must delegate calls.
*/
public CheckClassAdapter(final ClassVisitor classVisitor) {
this(classVisitor, true);
}
/**
* Constructs a new {@link CheckClassAdapter}. Subclasses must not use this constructor.
* Instead, they must use the {@link #CheckClassAdapter(int, ClassVisitor, boolean)} version.
*
* @param classVisitor the class visitor to which this adapter must delegate calls.
* @param checkDataFlow whether to perform basic data flow checks. This option requires valid
* maxLocals and maxStack values.
* @throws IllegalStateException If a subclass calls this constructor.
*/
public CheckClassAdapter(final ClassVisitor classVisitor, final boolean checkDataFlow) {
this(Opcodes.ASM6, classVisitor, checkDataFlow);
if (getClass() != CheckClassAdapter.class) {
throw new IllegalStateException();
}
}
/**
* Constructs a new {@link CheckClassAdapter}.
*
* @param api the ASM API version implemented by this visitor. Must be one of {@link
* Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link
* Opcodes#ASM7_EXPERIMENTAL}.
* @param classVisitor the class visitor to which this adapter must delegate calls.
* @param checkDataFlow true to perform basic data flow checks, or false to not
* perform any data flow check (see {@link CheckMethodAdapter}). This option requires valid
* maxLocals and maxStack values.
*/
protected CheckClassAdapter(
final int api, final ClassVisitor classVisitor, final boolean checkDataFlow) {
super(api, classVisitor);
this.labelInsnIndices = new HashMap();
this.checkDataFlow = checkDataFlow;
}
// -----------------------------------------------------------------------------------------------
// Implementation of the ClassVisitor interface
// -----------------------------------------------------------------------------------------------
@Override
public void visit(
final int version,
final int access,
final String name,
final String signature,
final String superName,
final String[] interfaces) {
if (visitCalled) {
throw new IllegalStateException("visit must be called only once");
}
visitCalled = true;
checkState();
checkAccess(
access,
Opcodes.ACC_PUBLIC
| Opcodes.ACC_FINAL
| Opcodes.ACC_SUPER
| Opcodes.ACC_INTERFACE
| Opcodes.ACC_ABSTRACT
| Opcodes.ACC_SYNTHETIC
| Opcodes.ACC_ANNOTATION
| Opcodes.ACC_ENUM
| Opcodes.ACC_DEPRECATED
| Opcodes.ACC_MODULE);
if (name == null) {
throw new IllegalArgumentException("Illegal class name (null)");
}
if (!name.endsWith("package-info") && !name.endsWith("module-info")) {
CheckMethodAdapter.checkInternalName(version, name, "class name");
}
if ("java/lang/Object".equals(name)) {
if (superName != null) {
throw new IllegalArgumentException(
"The super class name of the Object class must be 'null'");
}
} else if (name.endsWith("module-info")) {
if (superName != null) {
throw new IllegalArgumentException(
"The super class name of a module-info class must be 'null'");
}
} else {
CheckMethodAdapter.checkInternalName(version, superName, "super class name");
}
if (signature != null) {
checkClassSignature(signature);
}
if ((access & Opcodes.ACC_INTERFACE) != 0 && !"java/lang/Object".equals(superName)) {
throw new IllegalArgumentException(
"The super class name of interfaces must be 'java/lang/Object'");
}
if (interfaces != null) {
for (int i = 0; i < interfaces.length; ++i) {
CheckMethodAdapter.checkInternalName(
version, interfaces[i], "interface name at index " + i);
}
}
this.version = version;
super.visit(version, access, name, signature, superName, interfaces);
}
@Override
public void visitSource(final String file, final String debug) {
checkState();
if (visitSourceCalled) {
throw new IllegalStateException("visitSource can be called only once.");
}
visitSourceCalled = true;
super.visitSource(file, debug);
}
@Override
public ModuleVisitor visitModule(final String name, final int access, final String version) {
checkState();
if (visitModuleCalled) {
throw new IllegalStateException("visitModule can be called only once.");
}
visitModuleCalled = true;
checkFullyQualifiedName(this.version, name, "module name");
checkAccess(access, Opcodes.ACC_OPEN | Opcodes.ACC_SYNTHETIC | Opcodes.ACC_MANDATED);
CheckModuleAdapter checkModuleAdapter =
new CheckModuleAdapter(
api, super.visitModule(name, access, version), (access & Opcodes.ACC_OPEN) != 0);
checkModuleAdapter.classVersion = this.version;
return checkModuleAdapter;
}
@Override
public void visitNestHostExperimental(final String nestHost) {
checkState();
CheckMethodAdapter.checkInternalName(version, nestHost, "nestHost");
if (visitNestHostCalled) {
throw new IllegalStateException("visitNestHost can be called only once.");
}
if (nestMemberPackageName != null) {
throw new IllegalStateException("visitNestHost and visitNestMember are mutually exclusive.");
}
visitNestHostCalled = true;
super.visitNestHostExperimental(nestHost);
}
@Override
public void visitNestMemberExperimental(final String nestMember) {
checkState();
CheckMethodAdapter.checkInternalName(version, nestMember, "nestMember");
if (visitNestHostCalled) {
throw new IllegalStateException(
"visitMemberOfNest and visitNestHost are mutually exclusive.");
}
String packageName = packageName(nestMember);
if (nestMemberPackageName == null) {
nestMemberPackageName = packageName;
} else if (!nestMemberPackageName.equals(packageName)) {
throw new IllegalStateException(
"nest member " + nestMember + " should be in the package " + nestMemberPackageName);
}
super.visitNestMemberExperimental(nestMember);
}
@Override
public void visitOuterClass(final String owner, final String name, final String descriptor) {
checkState();
if (visitOuterClassCalled) {
throw new IllegalStateException("visitOuterClass can be called only once.");
}
visitOuterClassCalled = true;
if (owner == null) {
throw new IllegalArgumentException("Illegal outer class owner");
}
if (descriptor != null) {
CheckMethodAdapter.checkMethodDescriptor(version, descriptor);
}
super.visitOuterClass(owner, name, descriptor);
}
@Override
public void visitInnerClass(
final String name, final String outerName, final String innerName, final int access) {
checkState();
CheckMethodAdapter.checkInternalName(version, name, "class name");
if (outerName != null) {
CheckMethodAdapter.checkInternalName(version, outerName, "outer class name");
}
if (innerName != null) {
int startIndex = 0;
while (startIndex < innerName.length() && Character.isDigit(innerName.charAt(startIndex))) {
startIndex++;
}
if (startIndex == 0 || startIndex < innerName.length()) {
CheckMethodAdapter.checkIdentifier(version, innerName, startIndex, -1, "inner class name");
}
}
checkAccess(
access,
Opcodes.ACC_PUBLIC
| Opcodes.ACC_PRIVATE
| Opcodes.ACC_PROTECTED
| Opcodes.ACC_STATIC
| Opcodes.ACC_FINAL
| Opcodes.ACC_INTERFACE
| Opcodes.ACC_ABSTRACT
| Opcodes.ACC_SYNTHETIC
| Opcodes.ACC_ANNOTATION
| Opcodes.ACC_ENUM);
super.visitInnerClass(name, outerName, innerName, access);
}
@Override
public FieldVisitor visitField(
final int access,
final String name,
final String descriptor,
final String signature,
final Object value) {
checkState();
checkAccess(
access,
Opcodes.ACC_PUBLIC
| Opcodes.ACC_PRIVATE
| Opcodes.ACC_PROTECTED
| Opcodes.ACC_STATIC
| Opcodes.ACC_FINAL
| Opcodes.ACC_VOLATILE
| Opcodes.ACC_TRANSIENT
| Opcodes.ACC_SYNTHETIC
| Opcodes.ACC_ENUM
| Opcodes.ACC_DEPRECATED);
CheckMethodAdapter.checkUnqualifiedName(version, name, "field name");
CheckMethodAdapter.checkDescriptor(version, descriptor, /* canBeVoid = */ false);
if (signature != null) {
checkFieldSignature(signature);
}
if (value != null) {
CheckMethodAdapter.checkConstant(value);
}
return new CheckFieldAdapter(api, super.visitField(access, name, descriptor, signature, value));
}
@Override
public MethodVisitor visitMethod(
final int access,
final String name,
final String descriptor,
final String signature,
final String[] exceptions) {
checkState();
checkAccess(
access,
Opcodes.ACC_PUBLIC
| Opcodes.ACC_PRIVATE
| Opcodes.ACC_PROTECTED
| Opcodes.ACC_STATIC
| Opcodes.ACC_FINAL
| Opcodes.ACC_SYNCHRONIZED
| Opcodes.ACC_BRIDGE
| Opcodes.ACC_VARARGS
| Opcodes.ACC_NATIVE
| Opcodes.ACC_ABSTRACT
| Opcodes.ACC_STRICT
| Opcodes.ACC_SYNTHETIC
| Opcodes.ACC_DEPRECATED);
if (!"".equals(name) && !"".equals(name)) {
CheckMethodAdapter.checkMethodIdentifier(version, name, "method name");
}
CheckMethodAdapter.checkMethodDescriptor(version, descriptor);
if (signature != null) {
checkMethodSignature(signature);
}
if (exceptions != null) {
for (int i = 0; i < exceptions.length; ++i) {
CheckMethodAdapter.checkInternalName(
version, exceptions[i], "exception name at index " + i);
}
}
CheckMethodAdapter checkMethodAdapter;
if (checkDataFlow) {
checkMethodAdapter =
new CheckMethodAdapter(
api,
access,
name,
descriptor,
super.visitMethod(access, name, descriptor, signature, exceptions),
labelInsnIndices);
} else {
checkMethodAdapter =
new CheckMethodAdapter(
api,
super.visitMethod(access, name, descriptor, signature, exceptions),
labelInsnIndices);
}
checkMethodAdapter.version = version;
return checkMethodAdapter;
}
@Override
public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
checkState();
CheckMethodAdapter.checkDescriptor(version, descriptor, false);
return new CheckAnnotationAdapter(super.visitAnnotation(descriptor, visible));
}
@Override
public AnnotationVisitor visitTypeAnnotation(
final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
checkState();
int sort = new TypeReference(typeRef).getSort();
if (sort != TypeReference.CLASS_TYPE_PARAMETER
&& sort != TypeReference.CLASS_TYPE_PARAMETER_BOUND
&& sort != TypeReference.CLASS_EXTENDS) {
throw new IllegalArgumentException(
"Invalid type reference sort 0x" + Integer.toHexString(sort));
}
checkTypeRef(typeRef);
CheckMethodAdapter.checkDescriptor(version, descriptor, false);
return new CheckAnnotationAdapter(
super.visitTypeAnnotation(typeRef, typePath, descriptor, visible));
}
@Override
public void visitAttribute(final Attribute attribute) {
checkState();
if (attribute == null) {
throw new IllegalArgumentException("Invalid attribute (must not be null)");
}
super.visitAttribute(attribute);
}
@Override
public void visitEnd() {
checkState();
visitEndCalled = true;
super.visitEnd();
}
// -----------------------------------------------------------------------------------------------
// Utility methods
// -----------------------------------------------------------------------------------------------
/** Checks that the visit method has been called and that visitEnd has not been called. */
private void checkState() {
if (!visitCalled) {
throw new IllegalStateException("Cannot visit member before visit has been called.");
}
if (visitEndCalled) {
throw new IllegalStateException("Cannot visit member after visitEnd has been called.");
}
}
/**
* Checks that the given access flags do not contain invalid flags. This method also checks that
* mutually incompatible flags are not set simultaneously.
*
* @param access the access flags to be checked.
* @param possibleAccess the valid access flags.
*/
static void checkAccess(final int access, final int possibleAccess) {
if ((access & ~possibleAccess) != 0) {
throw new IllegalArgumentException("Invalid access flags: " + access);
}
int publicProtectedPrivate = Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED | Opcodes.ACC_PRIVATE;
if (Integer.bitCount(access & publicProtectedPrivate) > 1) {
throw new IllegalArgumentException(
"public, protected and private are mutually exclusive: " + access);
}
if (Integer.bitCount(access & (Opcodes.ACC_FINAL | Opcodes.ACC_ABSTRACT)) > 1) {
throw new IllegalArgumentException("final and abstract are mutually exclusive: " + access);
}
}
/**
* Checks that the given name is a fully qualified name, using dots.
*
* @param version the class version.
* @param name the name to be checked.
* @param source the source of 'name' (e.g 'module' for a module name).
*/
static void checkFullyQualifiedName(final int version, final String name, final String source) {
try {
int startIndex = 0;
int dotIndex;
while ((dotIndex = name.indexOf('.', startIndex + 1)) != -1) {
CheckMethodAdapter.checkIdentifier(version, name, startIndex, dotIndex, null);
startIndex = dotIndex + 1;
}
CheckMethodAdapter.checkIdentifier(version, name, startIndex, name.length(), null);
} catch (IllegalArgumentException e) {
throw new IllegalArgumentException(
"Invalid " + source + " (must be a fully qualified name): " + name);
}
}
/**
* Checks a class signature.
*
* @param signature a string containing the signature that must be checked.
*/
public static void checkClassSignature(final String signature) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// ClassSignature:
// [TypeParameters] SuperclassSignature SuperinterfaceSignature*
// SuperclassSignature:
// ClassTypeSignature
// SuperinterfaceSignature:
// ClassTypeSignature
int pos = 0;
if (getChar(signature, 0) == '<') {
pos = checkTypeParameters(signature, pos);
}
pos = checkClassTypeSignature(signature, pos);
while (getChar(signature, pos) == 'L') {
pos = checkClassTypeSignature(signature, pos);
}
if (pos != signature.length()) {
throw new IllegalArgumentException(signature + ERROR_AT + pos);
}
}
/**
* Checks a method signature.
*
* @param signature a string containing the signature that must be checked.
*/
public static void checkMethodSignature(final String signature) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// MethodSignature:
// [TypeParameters] ( JavaTypeSignature* ) Result ThrowsSignature*
// Result:
// JavaTypeSignature
// VoidDescriptor
// ThrowsSignature:
// ^ ClassTypeSignature
// ^ TypeVariableSignature
int pos = 0;
if (getChar(signature, 0) == '<') {
pos = checkTypeParameters(signature, pos);
}
pos = checkChar('(', signature, pos);
while ("ZCBSIFJDL[T".indexOf(getChar(signature, pos)) != -1) {
pos = checkJavaTypeSignature(signature, pos);
}
pos = checkChar(')', signature, pos);
if (getChar(signature, pos) == 'V') {
++pos;
} else {
pos = checkJavaTypeSignature(signature, pos);
}
while (getChar(signature, pos) == '^') {
++pos;
if (getChar(signature, pos) == 'L') {
pos = checkClassTypeSignature(signature, pos);
} else {
pos = checkTypeVariableSignature(signature, pos);
}
}
if (pos != signature.length()) {
throw new IllegalArgumentException(signature + ERROR_AT + pos);
}
}
/**
* Checks a field signature.
*
* @param signature a string containing the signature that must be checked.
*/
public static void checkFieldSignature(final String signature) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// FieldSignature:
// ReferenceTypeSignature
int pos = checkReferenceTypeSignature(signature, 0);
if (pos != signature.length()) {
throw new IllegalArgumentException(signature + ERROR_AT + pos);
}
}
/**
* Checks the type parameters of a class or method signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkTypeParameters(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// TypeParameters:
// < TypeParameter TypeParameter* >
int pos = startPos;
pos = checkChar('<', signature, pos);
pos = checkTypeParameter(signature, pos);
while (getChar(signature, pos) != '>') {
pos = checkTypeParameter(signature, pos);
}
return pos + 1;
}
/**
* Checks a type parameter of a class or method signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkTypeParameter(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// TypeParameter:
// Identifier ClassBound InterfaceBound*
// ClassBound:
// : [ReferenceTypeSignature]
// InterfaceBound:
// : ReferenceTypeSignature
int pos = startPos;
pos = checkSignatureIdentifier(signature, pos);
pos = checkChar(':', signature, pos);
if ("L[T".indexOf(getChar(signature, pos)) != -1) {
pos = checkReferenceTypeSignature(signature, pos);
}
while (getChar(signature, pos) == ':') {
pos = checkReferenceTypeSignature(signature, pos + 1);
}
return pos;
}
/**
* Checks a reference type signature.
*
* @param signature a string containing the signature that must be checked.
* @param pos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkReferenceTypeSignature(final String signature, final int pos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// ReferenceTypeSignature:
// ClassTypeSignature
// TypeVariableSignature
// ArrayTypeSignature
// ArrayTypeSignature:
// [ JavaTypeSignature
switch (getChar(signature, pos)) {
case 'L':
return checkClassTypeSignature(signature, pos);
case '[':
return checkJavaTypeSignature(signature, pos + 1);
default:
return checkTypeVariableSignature(signature, pos);
}
}
/**
* Checks a class type signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkClassTypeSignature(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// ClassTypeSignature:
// L [PackageSpecifier] SimpleClassTypeSignature ClassTypeSignatureSuffix* ;
// PackageSpecifier:
// Identifier / PackageSpecifier*
// SimpleClassTypeSignature:
// Identifier [TypeArguments]
// ClassTypeSignatureSuffix:
// . SimpleClassTypeSignature
int pos = startPos;
pos = checkChar('L', signature, pos);
pos = checkSignatureIdentifier(signature, pos);
while (getChar(signature, pos) == '/') {
pos = checkSignatureIdentifier(signature, pos + 1);
}
if (getChar(signature, pos) == '<') {
pos = checkTypeArguments(signature, pos);
}
while (getChar(signature, pos) == '.') {
pos = checkSignatureIdentifier(signature, pos + 1);
if (getChar(signature, pos) == '<') {
pos = checkTypeArguments(signature, pos);
}
}
return checkChar(';', signature, pos);
}
/**
* Checks the type arguments in a class type signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkTypeArguments(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// TypeArguments:
// < TypeArgument TypeArgument* >
int pos = startPos;
pos = checkChar('<', signature, pos);
pos = checkTypeArgument(signature, pos);
while (getChar(signature, pos) != '>') {
pos = checkTypeArgument(signature, pos);
}
return pos + 1;
}
/**
* Checks a type argument in a class type signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkTypeArgument(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// TypeArgument:
// [WildcardIndicator] ReferenceTypeSignature
// *
// WildcardIndicator:
// +
// -
int pos = startPos;
char c = getChar(signature, pos);
if (c == '*') {
return pos + 1;
} else if (c == '+' || c == '-') {
pos++;
}
return checkReferenceTypeSignature(signature, pos);
}
/**
* Checks a type variable signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkTypeVariableSignature(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// TypeVariableSignature:
// T Identifier ;
int pos = startPos;
pos = checkChar('T', signature, pos);
pos = checkSignatureIdentifier(signature, pos);
return checkChar(';', signature, pos);
}
/**
* Checks a Java type signature.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkJavaTypeSignature(final String signature, final int startPos) {
// From https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.9.1:
// JavaTypeSignature:
// ReferenceTypeSignature
// BaseType
// BaseType:
// (one of)
// B C D F I J S Z
int pos = startPos;
switch (getChar(signature, pos)) {
case 'B':
case 'C':
case 'D':
case 'F':
case 'I':
case 'J':
case 'S':
case 'Z':
return pos + 1;
default:
return checkReferenceTypeSignature(signature, pos);
}
}
/**
* Checks an identifier.
*
* @param signature a string containing the signature that must be checked.
* @param startPos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkSignatureIdentifier(final String signature, final int startPos) {
int pos = startPos;
while (pos < signature.length() && ".;[/<>:".indexOf(signature.codePointAt(pos)) == -1) {
pos = signature.offsetByCodePoints(pos, 1);
}
if (pos == startPos) {
throw new IllegalArgumentException(signature + ": identifier expected at index " + startPos);
}
return pos;
}
/**
* Checks a single character.
*
* @param c a character.
* @param signature a string containing the signature that must be checked.
* @param pos index of first character to be checked.
* @return the index of the first character after the checked part.
*/
private static int checkChar(final char c, final String signature, final int pos) {
if (getChar(signature, pos) == c) {
return pos + 1;
}
throw new IllegalArgumentException(signature + ": '" + c + "' expected at index " + pos);
}
/**
* Returns the string character at the given index, or 0.
*
* @param string a string.
* @param pos an index in 'string'.
* @return the character at the given index, or 0 if there is no such character.
*/
private static char getChar(final String string, final int pos) {
return pos < string.length() ? string.charAt(pos) : (char) 0;
}
/**
* Checks the reference to a type in a type annotation.
*
* @param typeRef a reference to an annotated type.
*/
static void checkTypeRef(final int typeRef) {
int mask = 0;
switch (typeRef >>> 24) {
case TypeReference.CLASS_TYPE_PARAMETER:
case TypeReference.METHOD_TYPE_PARAMETER:
case TypeReference.METHOD_FORMAL_PARAMETER:
mask = 0xFFFF0000;
break;
case TypeReference.FIELD:
case TypeReference.METHOD_RETURN:
case TypeReference.METHOD_RECEIVER:
case TypeReference.LOCAL_VARIABLE:
case TypeReference.RESOURCE_VARIABLE:
case TypeReference.INSTANCEOF:
case TypeReference.NEW:
case TypeReference.CONSTRUCTOR_REFERENCE:
case TypeReference.METHOD_REFERENCE:
mask = 0xFF000000;
break;
case TypeReference.CLASS_EXTENDS:
case TypeReference.CLASS_TYPE_PARAMETER_BOUND:
case TypeReference.METHOD_TYPE_PARAMETER_BOUND:
case TypeReference.THROWS:
case TypeReference.EXCEPTION_PARAMETER:
mask = 0xFFFFFF00;
break;
case TypeReference.CAST:
case TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT:
case TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT:
case TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT:
case TypeReference.METHOD_REFERENCE_TYPE_ARGUMENT:
mask = 0xFF0000FF;
break;
default:
throw new AssertionError();
}
if ((typeRef & ~mask) != 0) {
throw new IllegalArgumentException(
"Invalid type reference 0x" + Integer.toHexString(typeRef));
}
}
/**
* Returns the package name of an internal name.
*
* @param name an internal name.
* @return the package name or "" if there is no package.
*/
private static String packageName(final String name) {
int index = name.lastIndexOf('/');
if (index == -1) {
return "";
}
return name.substring(0, index);
}
}