/***
* 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 nginx.clojure.asm.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import nginx.clojure.asm.AnnotationVisitor;
import nginx.clojure.asm.Attribute;
import nginx.clojure.asm.Handle;
import nginx.clojure.asm.Label;
import nginx.clojure.asm.MethodVisitor;
import nginx.clojure.asm.Opcodes;
import nginx.clojure.asm.Type;
import nginx.clojure.asm.tree.MethodNode;
import nginx.clojure.asm.tree.analysis.Analyzer;
import nginx.clojure.asm.tree.analysis.BasicValue;
import nginx.clojure.asm.tree.analysis.BasicVerifier;
/**
* A {@link MethodVisitor} that checks that its methods are properly used. More
* precisely this method adapter checks each instruction individually, i.e.,
* each visit method checks some preconditions based <i>only</i> on its
* arguments - such as the fact that the given opcode is correct for a given
* visit method. This adapter can also perform some basic data flow checks (more
* precisely those that can be performed without the full class hierarchy - see
* {@link nginx.clojure.asm.tree.analysis.BasicVerifier}). For instance in a
* method whose signature is <tt>void m ()</tt>, the invalid instruction
* IRETURN, or the invalid sequence IADD L2I will be detected if the data flow
* checks are enabled. These checks are enabled by using the
* {@link #CheckMethodAdapter(int,String,String,MethodVisitor,Map)} constructor.
* They are not performed if any other constructor is used.
*
* @author Eric Bruneton
*/
public class CheckMethodAdapter extends MethodVisitor {
/**
* The class version number.
*/
public int version;
/**
* The access flags of the method.
*/
private int access;
/**
* <tt>true</tt> if the visitCode method has been called.
*/
private boolean startCode;
/**
* <tt>true</tt> if the visitMaxs method has been called.
*/
private boolean endCode;
/**
* <tt>true</tt> if the visitEnd method has been called.
*/
private boolean endMethod;
/**
* Number of visited instructions.
*/
private int insnCount;
/**
* The already visited labels. This map associate Integer values to pseudo
* code offsets.
*/
private final Map<Label, Integer> labels;
/**
* The labels used in this method. Every used label must be visited with
* visitLabel before the end of the method (i.e. should be in #labels).
*/
private Set<Label> usedLabels;
/**
* Number of visited frames in expanded form.
*/
private int expandedFrames;
/**
* Number of visited frames in compressed form.
*/
private int compressedFrames;
/**
* Number of instructions before the last visited frame.
*/
private int lastFrame = -1;
/**
* The exception handler ranges. Each pair of list element contains the
* start and end labels of an exception handler block.
*/
private List<Label> handlers;
/**
* Code of the visit method to be used for each opcode.
*/
private static final int[] TYPE;
/**
* The Label.status field.
*/
private static Field labelStatusField;
static {
String s = "BBBBBBBBBBBBBBBBCCIAADDDDDAAAAAAAAAAAAAAAAAAAABBBBBBBBDD"
+ "DDDAAAAAAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"
+ "BBBBBBBBBBBBBBBBBBBJBBBBBBBBBBBBBBBBBBBBHHHHHHHHHHHHHHHHD"
+ "KLBBBBBBFFFFGGGGAECEBBEEBBAMHHAA";
TYPE = new int[s.length()];
for (int i = 0; i < TYPE.length; ++i) {
TYPE[i] = s.charAt(i) - 'A' - 1;
}
}
// code to generate the above string
// public static void main (String[] args) {
// int[] TYPE = new int[] {
// 0, //NOP
// 0, //ACONST_NULL
// 0, //ICONST_M1
// 0, //ICONST_0
// 0, //ICONST_1
// 0, //ICONST_2
// 0, //ICONST_3
// 0, //ICONST_4
// 0, //ICONST_5
// 0, //LCONST_0
// 0, //LCONST_1
// 0, //FCONST_0
// 0, //FCONST_1
// 0, //FCONST_2
// 0, //DCONST_0
// 0, //DCONST_1
// 1, //BIPUSH
// 1, //SIPUSH
// 7, //LDC
// -1, //LDC_W
// -1, //LDC2_W
// 2, //ILOAD
// 2, //LLOAD
// 2, //FLOAD
// 2, //DLOAD
// 2, //ALOAD
// -1, //ILOAD_0
// -1, //ILOAD_1
// -1, //ILOAD_2
// -1, //ILOAD_3
// -1, //LLOAD_0
// -1, //LLOAD_1
// -1, //LLOAD_2
// -1, //LLOAD_3
// -1, //FLOAD_0
// -1, //FLOAD_1
// -1, //FLOAD_2
// -1, //FLOAD_3
// -1, //DLOAD_0
// -1, //DLOAD_1
// -1, //DLOAD_2
// -1, //DLOAD_3
// -1, //ALOAD_0
// -1, //ALOAD_1
// -1, //ALOAD_2
// -1, //ALOAD_3
// 0, //IALOAD
// 0, //LALOAD
// 0, //FALOAD
// 0, //DALOAD
// 0, //AALOAD
// 0, //BALOAD
// 0, //CALOAD
// 0, //SALOAD
// 2, //ISTORE
// 2, //LSTORE
// 2, //FSTORE
// 2, //DSTORE
// 2, //ASTORE
// -1, //ISTORE_0
// -1, //ISTORE_1
// -1, //ISTORE_2
// -1, //ISTORE_3
// -1, //LSTORE_0
// -1, //LSTORE_1
// -1, //LSTORE_2
// -1, //LSTORE_3
// -1, //FSTORE_0
// -1, //FSTORE_1
// -1, //FSTORE_2
// -1, //FSTORE_3
// -1, //DSTORE_0
// -1, //DSTORE_1
// -1, //DSTORE_2
// -1, //DSTORE_3
// -1, //ASTORE_0
// -1, //ASTORE_1
// -1, //ASTORE_2
// -1, //ASTORE_3
// 0, //IASTORE
// 0, //LASTORE
// 0, //FASTORE
// 0, //DASTORE
// 0, //AASTORE
// 0, //BASTORE
// 0, //CASTORE
// 0, //SASTORE
// 0, //POP
// 0, //POP2
// 0, //DUP
// 0, //DUP_X1
// 0, //DUP_X2
// 0, //DUP2
// 0, //DUP2_X1
// 0, //DUP2_X2
// 0, //SWAP
// 0, //IADD
// 0, //LADD
// 0, //FADD
// 0, //DADD
// 0, //ISUB
// 0, //LSUB
// 0, //FSUB
// 0, //DSUB
// 0, //IMUL
// 0, //LMUL
// 0, //FMUL
// 0, //DMUL
// 0, //IDIV
// 0, //LDIV
// 0, //FDIV
// 0, //DDIV
// 0, //IREM
// 0, //LREM
// 0, //FREM
// 0, //DREM
// 0, //INEG
// 0, //LNEG
// 0, //FNEG
// 0, //DNEG
// 0, //ISHL
// 0, //LSHL
// 0, //ISHR
// 0, //LSHR
// 0, //IUSHR
// 0, //LUSHR
// 0, //IAND
// 0, //LAND
// 0, //IOR
// 0, //LOR
// 0, //IXOR
// 0, //LXOR
// 8, //IINC
// 0, //I2L
// 0, //I2F
// 0, //I2D
// 0, //L2I
// 0, //L2F
// 0, //L2D
// 0, //F2I
// 0, //F2L
// 0, //F2D
// 0, //D2I
// 0, //D2L
// 0, //D2F
// 0, //I2B
// 0, //I2C
// 0, //I2S
// 0, //LCMP
// 0, //FCMPL
// 0, //FCMPG
// 0, //DCMPL
// 0, //DCMPG
// 6, //IFEQ
// 6, //IFNE
// 6, //IFLT
// 6, //IFGE
// 6, //IFGT
// 6, //IFLE
// 6, //IF_ICMPEQ
// 6, //IF_ICMPNE
// 6, //IF_ICMPLT
// 6, //IF_ICMPGE
// 6, //IF_ICMPGT
// 6, //IF_ICMPLE
// 6, //IF_ACMPEQ
// 6, //IF_ACMPNE
// 6, //GOTO
// 6, //JSR
// 2, //RET
// 9, //TABLESWITCH
// 10, //LOOKUPSWITCH
// 0, //IRETURN
// 0, //LRETURN
// 0, //FRETURN
// 0, //DRETURN
// 0, //ARETURN
// 0, //RETURN
// 4, //GETSTATIC
// 4, //PUTSTATIC
// 4, //GETFIELD
// 4, //PUTFIELD
// 5, //INVOKEVIRTUAL
// 5, //INVOKESPECIAL
// 5, //INVOKESTATIC
// 5, //INVOKEINTERFACE
// -1, //INVOKEDYNAMIC
// 3, //NEW
// 1, //NEWARRAY
// 3, //ANEWARRAY
// 0, //ARRAYLENGTH
// 0, //ATHROW
// 3, //CHECKCAST
// 3, //INSTANCEOF
// 0, //MONITORENTER
// 0, //MONITOREXIT
// -1, //WIDE
// 11, //MULTIANEWARRAY
// 6, //IFNULL
// 6, //IFNONNULL
// -1, //GOTO_W
// -1 //JSR_W
// };
// for (int i = 0; i < TYPE.length; ++i) {
// System.out.print((char)(TYPE[i] + 1 + 'A'));
// }
// System.out.println();
// }
/**
* Constructs a new {@link CheckMethodAdapter} object. This method adapter
* will not perform any data flow check (see
* {@link #CheckMethodAdapter(int,String,String,MethodVisitor,Map)}).
* <i>Subclasses must not use this constructor</i>. Instead, they must use
* the {@link #CheckMethodAdapter(int, MethodVisitor, Map)} version.
*
* @param mv
* the method visitor to which this adapter must delegate calls.
*/
public CheckMethodAdapter(final MethodVisitor mv) {
this(mv, new HashMap<Label, Integer>());
}
/**
* Constructs a new {@link CheckMethodAdapter} object. This method adapter
* will not perform any data flow check (see
* {@link #CheckMethodAdapter(int,String,String,MethodVisitor,Map)}).
* <i>Subclasses must not use this constructor</i>. Instead, they must use
* the {@link #CheckMethodAdapter(int, MethodVisitor, Map)} version.
*
* @param mv
* the method visitor to which this adapter must delegate calls.
* @param labels
* a map of already visited labels (in other methods).
*/
public CheckMethodAdapter(final MethodVisitor mv,
final Map<Label, Integer> labels) {
this(Opcodes.ASM4, mv, labels);
}
/**
* Constructs a new {@link CheckMethodAdapter} object. This method adapter
* will not perform any data flow check (see
* {@link #CheckMethodAdapter(int,String,String,MethodVisitor,Map)}).
*
* @param mv
* the method visitor to which this adapter must delegate calls.
* @param labels
* a map of already visited labels (in other methods).
*/
protected CheckMethodAdapter(final int api, final MethodVisitor mv,
final Map<Label, Integer> labels) {
super(api, mv);
this.labels = labels;
this.usedLabels = new HashSet<Label>();
this.handlers = new ArrayList<Label>();
}
/**
* Constructs a new {@link CheckMethodAdapter} object. This method adapter
* will perform basic data flow checks. For instance in a method whose
* signature is <tt>void m ()</tt>, the invalid instruction IRETURN, or the
* invalid sequence IADD L2I will be detected.
*
* @param access
* the method's access flags.
* @param name
* the method's name.
* @param desc
* the method's descriptor (see {@link Type Type}).
* @param cmv
* the method visitor to which this adapter must delegate calls.
* @param labels
* a map of already visited labels (in other methods).
*/
public CheckMethodAdapter(final int access, final String name,
final String desc, final MethodVisitor cmv,
final Map<Label, Integer> labels) {
this(new MethodNode(access, name, desc, null, null) {
@Override
public void visitEnd() {
Analyzer<BasicValue> a = new Analyzer<BasicValue>(
new BasicVerifier());
try {
a.analyze("dummy", this);
} catch (Exception e) {
if (e instanceof IndexOutOfBoundsException
&& maxLocals == 0 && maxStack == 0) {
throw new RuntimeException(
"Data flow checking option requires valid, non zero maxLocals and maxStack values.");
}
e.printStackTrace();
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw, true);
CheckClassAdapter.printAnalyzerResult(this, a, pw);
pw.close();
throw new RuntimeException(e.getMessage() + ' '
+ sw.toString());
}
accept(cmv);
}
}, labels);
this.access = access;
}
@Override
public AnnotationVisitor visitAnnotation(final String desc,
final boolean visible) {
checkEndMethod();
checkDesc(desc, false);
return new CheckAnnotationAdapter(super.visitAnnotation(desc, visible));
}
@Override
public AnnotationVisitor visitAnnotationDefault() {
checkEndMethod();
return new CheckAnnotationAdapter(super.visitAnnotationDefault(), false);
}
@Override
public AnnotationVisitor visitParameterAnnotation(final int parameter,
final String desc, final boolean visible) {
checkEndMethod();
checkDesc(desc, false);
return new CheckAnnotationAdapter(super.visitParameterAnnotation(
parameter, desc, visible));
}
@Override
public void visitAttribute(final Attribute attr) {
checkEndMethod();
if (attr == null) {
throw new IllegalArgumentException(
"Invalid attribute (must not be null)");
}
super.visitAttribute(attr);
}
@Override
public void visitCode() {
if ((access & Opcodes.ACC_ABSTRACT) != 0) {
throw new RuntimeException("Abstract methods cannot have code");
}
startCode = true;
super.visitCode();
}
@Override
public void visitFrame(final int type, final int nLocal,
final Object[] local, final int nStack, final Object[] stack) {
if (insnCount == lastFrame) {
throw new IllegalStateException(
"At most one frame can be visited at a given code location.");
}
lastFrame = insnCount;
int mLocal;
int mStack;
switch (type) {
case Opcodes.F_NEW:
case Opcodes.F_FULL:
mLocal = Integer.MAX_VALUE;
mStack = Integer.MAX_VALUE;
break;
case Opcodes.F_SAME:
mLocal = 0;
mStack = 0;
break;
case Opcodes.F_SAME1:
mLocal = 0;
mStack = 1;
break;
case Opcodes.F_APPEND:
case Opcodes.F_CHOP:
mLocal = 3;
mStack = 0;
break;
default:
throw new IllegalArgumentException("Invalid frame type " + type);
}
if (nLocal > mLocal) {
throw new IllegalArgumentException("Invalid nLocal=" + nLocal
+ " for frame type " + type);
}
if (nStack > mStack) {
throw new IllegalArgumentException("Invalid nStack=" + nStack
+ " for frame type " + type);
}
if (type != Opcodes.F_CHOP) {
if (nLocal > 0 && (local == null || local.length < nLocal)) {
throw new IllegalArgumentException(
"Array local[] is shorter than nLocal");
}
for (int i = 0; i < nLocal; ++i) {
checkFrameValue(local[i]);
}
}
if (nStack > 0 && (stack == null || stack.length < nStack)) {
throw new IllegalArgumentException(
"Array stack[] is shorter than nStack");
}
for (int i = 0; i < nStack; ++i) {
checkFrameValue(stack[i]);
}
if (type == Opcodes.F_NEW) {
++expandedFrames;
} else {
++compressedFrames;
}
if (expandedFrames > 0 && compressedFrames > 0) {
throw new RuntimeException(
"Expanded and compressed frames must not be mixed.");
}
super.visitFrame(type, nLocal, local, nStack, stack);
}
@Override
public void visitInsn(final int opcode) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 0);
super.visitInsn(opcode);
++insnCount;
}
@Override
public void visitIntInsn(final int opcode, final int operand) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 1);
switch (opcode) {
case Opcodes.BIPUSH:
checkSignedByte(operand, "Invalid operand");
break;
case Opcodes.SIPUSH:
checkSignedShort(operand, "Invalid operand");
break;
// case Constants.NEWARRAY:
default:
if (operand < Opcodes.T_BOOLEAN || operand > Opcodes.T_LONG) {
throw new IllegalArgumentException(
"Invalid operand (must be an array type code T_...): "
+ operand);
}
}
super.visitIntInsn(opcode, operand);
++insnCount;
}
@Override
public void visitVarInsn(final int opcode, final int var) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 2);
checkUnsignedShort(var, "Invalid variable index");
super.visitVarInsn(opcode, var);
++insnCount;
}
@Override
public void visitTypeInsn(final int opcode, final String type) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 3);
checkInternalName(type, "type");
if (opcode == Opcodes.NEW && type.charAt(0) == '[') {
throw new IllegalArgumentException(
"NEW cannot be used to create arrays: " + type);
}
super.visitTypeInsn(opcode, type);
++insnCount;
}
@Override
public void visitFieldInsn(final int opcode, final String owner,
final String name, final String desc) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 4);
checkInternalName(owner, "owner");
checkUnqualifiedName(version, name, "name");
checkDesc(desc, false);
super.visitFieldInsn(opcode, owner, name, desc);
++insnCount;
}
@Override
public void visitMethodInsn(final int opcode, final String owner,
final String name, final String desc) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 5);
if (opcode != Opcodes.INVOKESPECIAL || !"<init>".equals(name)) {
checkMethodIdentifier(version, name, "name");
}
checkInternalName(owner, "owner");
checkMethodDesc(desc);
super.visitMethodInsn(opcode, owner, name, desc);
++insnCount;
}
@Override
public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
Object... bsmArgs) {
checkStartCode();
checkEndCode();
checkMethodIdentifier(version, name, "name");
checkMethodDesc(desc);
if (bsm.getTag() != Opcodes.H_INVOKESTATIC
&& bsm.getTag() != Opcodes.H_NEWINVOKESPECIAL) {
throw new IllegalArgumentException("invalid handle tag "
+ bsm.getTag());
}
for (int i = 0; i < bsmArgs.length; i++) {
checkLDCConstant(bsmArgs[i]);
}
super.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
++insnCount;
}
@Override
public void visitJumpInsn(final int opcode, final Label label) {
checkStartCode();
checkEndCode();
checkOpcode(opcode, 6);
checkLabel(label, false, "label");
checkNonDebugLabel(label);
super.visitJumpInsn(opcode, label);
usedLabels.add(label);
++insnCount;
}
@Override
public void visitLabel(final Label label) {
checkStartCode();
checkEndCode();
checkLabel(label, false, "label");
if (labels.get(label) != null) {
throw new IllegalArgumentException("Already visited label");
}
labels.put(label, new Integer(insnCount));
super.visitLabel(label);
}
@Override
public void visitLdcInsn(final Object cst) {
checkStartCode();
checkEndCode();
checkLDCConstant(cst);
super.visitLdcInsn(cst);
++insnCount;
}
@Override
public void visitIincInsn(final int var, final int increment) {
checkStartCode();
checkEndCode();
checkUnsignedShort(var, "Invalid variable index");
checkSignedShort(increment, "Invalid increment");
super.visitIincInsn(var, increment);
++insnCount;
}
@Override
public void visitTableSwitchInsn(final int min, final int max,
final Label dflt, final Label... labels) {
checkStartCode();
checkEndCode();
if (max < min) {
throw new IllegalArgumentException("Max = " + max
+ " must be greater than or equal to min = " + min);
}
checkLabel(dflt, false, "default label");
checkNonDebugLabel(dflt);
if (labels == null || labels.length != max - min + 1) {
throw new IllegalArgumentException(
"There must be max - min + 1 labels");
}
for (int i = 0; i < labels.length; ++i) {
checkLabel(labels[i], false, "label at index " + i);
checkNonDebugLabel(labels[i]);
}
super.visitTableSwitchInsn(min, max, dflt, labels);
for (int i = 0; i < labels.length; ++i) {
usedLabels.add(labels[i]);
}
++insnCount;
}
@Override
public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
final Label[] labels) {
checkEndCode();
checkStartCode();
checkLabel(dflt, false, "default label");
checkNonDebugLabel(dflt);
if (keys == null || labels == null || keys.length != labels.length) {
throw new IllegalArgumentException(
"There must be the same number of keys and labels");
}
for (int i = 0; i < labels.length; ++i) {
checkLabel(labels[i], false, "label at index " + i);
checkNonDebugLabel(labels[i]);
}
super.visitLookupSwitchInsn(dflt, keys, labels);
usedLabels.add(dflt);
for (int i = 0; i < labels.length; ++i) {
usedLabels.add(labels[i]);
}
++insnCount;
}
@Override
public void visitMultiANewArrayInsn(final String desc, final int dims) {
checkStartCode();
checkEndCode();
checkDesc(desc, false);
if (desc.charAt(0) != '[') {
throw new IllegalArgumentException(
"Invalid descriptor (must be an array type descriptor): "
+ desc);
}
if (dims < 1) {
throw new IllegalArgumentException(
"Invalid dimensions (must be greater than 0): " + dims);
}
if (dims > desc.lastIndexOf('[') + 1) {
throw new IllegalArgumentException(
"Invalid dimensions (must not be greater than dims(desc)): "
+ dims);
}
super.visitMultiANewArrayInsn(desc, dims);
++insnCount;
}
@Override
public void visitTryCatchBlock(final Label start, final Label end,
final Label handler, final String type) {
checkStartCode();
checkEndCode();
checkLabel(start, false, "start label");
checkLabel(end, false, "end label");
checkLabel(handler, false, "handler label");
checkNonDebugLabel(start);
checkNonDebugLabel(end);
checkNonDebugLabel(handler);
if (labels.get(start) != null || labels.get(end) != null
|| labels.get(handler) != null) {
throw new IllegalStateException(
"Try catch blocks must be visited before their labels");
}
if (type != null) {
checkInternalName(type, "type");
}
super.visitTryCatchBlock(start, end, handler, type);
handlers.add(start);
handlers.add(end);
}
@Override
public void visitLocalVariable(final String name, final String desc,
final String signature, final Label start, final Label end,
final int index) {
checkStartCode();
checkEndCode();
checkUnqualifiedName(version, name, "name");
checkDesc(desc, false);
checkLabel(start, true, "start label");
checkLabel(end, true, "end label");
checkUnsignedShort(index, "Invalid variable index");
int s = labels.get(start).intValue();
int e = labels.get(end).intValue();
if (e < s) {
throw new IllegalArgumentException(
"Invalid start and end labels (end must be greater than start)");
}
super.visitLocalVariable(name, desc, signature, start, end, index);
}
@Override
public void visitLineNumber(final int line, final Label start) {
checkStartCode();
checkEndCode();
checkUnsignedShort(line, "Invalid line number");
checkLabel(start, true, "start label");
super.visitLineNumber(line, start);
}
@Override
public void visitMaxs(final int maxStack, final int maxLocals) {
checkStartCode();
checkEndCode();
endCode = true;
for (Label l : usedLabels) {
if (labels.get(l) == null) {
throw new IllegalStateException("Undefined label used");
}
}
for (int i = 0; i < handlers.size();) {
Integer start = labels.get(handlers.get(i++));
Integer end = labels.get(handlers.get(i++));
if (start == null || end == null) {
throw new IllegalStateException(
"Undefined try catch block labels");
}
if (end.intValue() <= start.intValue()) {
throw new IllegalStateException(
"Emty try catch block handler range");
}
}
checkUnsignedShort(maxStack, "Invalid max stack");
checkUnsignedShort(maxLocals, "Invalid max locals");
super.visitMaxs(maxStack, maxLocals);
}
@Override
public void visitEnd() {
checkEndMethod();
endMethod = true;
super.visitEnd();
}
// -------------------------------------------------------------------------
/**
* Checks that the visitCode method has been called.
*/
void checkStartCode() {
if (!startCode) {
throw new IllegalStateException(
"Cannot visit instructions before visitCode has been called.");
}
}
/**
* Checks that the visitMaxs method has not been called.
*/
void checkEndCode() {
if (endCode) {
throw new IllegalStateException(
"Cannot visit instructions after visitMaxs has been called.");
}
}
/**
* Checks that the visitEnd method has not been called.
*/
void checkEndMethod() {
if (endMethod) {
throw new IllegalStateException(
"Cannot visit elements after visitEnd has been called.");
}
}
/**
* Checks a stack frame value.
*
* @param value
* the value to be checked.
*/
void checkFrameValue(final Object value) {
if (value == Opcodes.TOP || value == Opcodes.INTEGER
|| value == Opcodes.FLOAT || value == Opcodes.LONG
|| value == Opcodes.DOUBLE || value == Opcodes.NULL
|| value == Opcodes.UNINITIALIZED_THIS) {
return;
}
if (value instanceof String) {
checkInternalName((String) value, "Invalid stack frame value");
return;
}
if (!(value instanceof Label)) {
throw new IllegalArgumentException("Invalid stack frame value: "
+ value);
} else {
usedLabels.add((Label) value);
}
}
/**
* Checks that the type of the given opcode is equal to the given type.
*
* @param opcode
* the opcode to be checked.
* @param type
* the expected opcode type.
*/
static void checkOpcode(final int opcode, final int type) {
if (opcode < 0 || opcode > 199 || TYPE[opcode] != type) {
throw new IllegalArgumentException("Invalid opcode: " + opcode);
}
}
/**
* Checks that the given value is a signed byte.
*
* @param value
* the value to be checked.
* @param msg
* an message to be used in case of error.
*/
static void checkSignedByte(final int value, final String msg) {
if (value < Byte.MIN_VALUE || value > Byte.MAX_VALUE) {
throw new IllegalArgumentException(msg
+ " (must be a signed byte): " + value);
}
}
/**
* Checks that the given value is a signed short.
*
* @param value
* the value to be checked.
* @param msg
* an message to be used in case of error.
*/
static void checkSignedShort(final int value, final String msg) {
if (value < Short.MIN_VALUE || value > Short.MAX_VALUE) {
throw new IllegalArgumentException(msg
+ " (must be a signed short): " + value);
}
}
/**
* Checks that the given value is an unsigned short.
*
* @param value
* the value to be checked.
* @param msg
* an message to be used in case of error.
*/
static void checkUnsignedShort(final int value, final String msg) {
if (value < 0 || value > 65535) {
throw new IllegalArgumentException(msg
+ " (must be an unsigned short): " + value);
}
}
/**
* Checks that the given value is an {@link Integer}, a{@link Float}, a
* {@link Long}, a {@link Double} or a {@link String}.
*
* @param cst
* the value to be checked.
*/
static void checkConstant(final Object cst) {
if (!(cst instanceof Integer) && !(cst instanceof Float)
&& !(cst instanceof Long) && !(cst instanceof Double)
&& !(cst instanceof String)) {
throw new IllegalArgumentException("Invalid constant: " + cst);
}
}
void checkLDCConstant(final Object cst) {
if (cst instanceof Type) {
int s = ((Type) cst).getSort();
if (s != Type.OBJECT && s != Type.ARRAY && s != Type.METHOD) {
throw new IllegalArgumentException("Illegal LDC constant value");
}
if (s != Type.METHOD && (version & 0xFFFF) < Opcodes.V1_5) {
throw new IllegalArgumentException(
"ldc of a constant class requires at least version 1.5");
}
if (s == Type.METHOD && (version & 0xFFFF) < Opcodes.V1_7) {
throw new IllegalArgumentException(
"ldc of a method type requires at least version 1.7");
}
} else if (cst instanceof Handle) {
if ((version & 0xFFFF) < Opcodes.V1_7) {
throw new IllegalArgumentException(
"ldc of a handle requires at least version 1.7");
}
int tag = ((Handle) cst).getTag();
if (tag < Opcodes.H_GETFIELD || tag > Opcodes.H_INVOKEINTERFACE) {
throw new IllegalArgumentException("invalid handle tag " + tag);
}
} else {
checkConstant(cst);
}
}
/**
* Checks that the given string is a valid unqualified name.
*
* @param version
* the class version.
* @param name
* the string to be checked.
* @param msg
* a message to be used in case of error.
*/
static void checkUnqualifiedName(int version, final String name,
final String msg) {
if ((version & 0xFFFF) < Opcodes.V1_5) {
checkIdentifier(name, msg);
} else {
for (int i = 0; i < name.length(); ++i) {
if (".;[/".indexOf(name.charAt(i)) != -1) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must be a valid unqualified name): " + name);
}
}
}
}
/**
* Checks that the given string is a valid Java identifier.
*
* @param name
* the string to be checked.
* @param msg
* a message to be used in case of error.
*/
static void checkIdentifier(final String name, final String msg) {
checkIdentifier(name, 0, -1, msg);
}
/**
* Checks that the given substring is a valid Java identifier.
*
* @param name
* the string to be checked.
* @param start
* index of the first character of the identifier (inclusive).
* @param end
* index of the last character of the identifier (exclusive). -1
* is equivalent to <tt>name.length()</tt> if name is not
* <tt>null</tt>.
* @param msg
* a message to be used in case of error.
*/
static void checkIdentifier(final String name, final int start,
final int end, final String msg) {
if (name == null || (end == -1 ? name.length() <= start : end <= start)) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must not be null or empty)");
}
if (!Character.isJavaIdentifierStart(name.charAt(start))) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must be a valid Java identifier): " + name);
}
int max = end == -1 ? name.length() : end;
for (int i = start + 1; i < max; ++i) {
if (!Character.isJavaIdentifierPart(name.charAt(i))) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must be a valid Java identifier): " + name);
}
}
}
/**
* Checks that the given string is a valid Java identifier.
*
* @param version
* the class version.
* @param name
* the string to be checked.
* @param msg
* a message to be used in case of error.
*/
static void checkMethodIdentifier(int version, final String name,
final String msg) {
if (name == null || name.length() == 0) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must not be null or empty)");
}
if ((version & 0xFFFF) >= Opcodes.V1_5) {
for (int i = 0; i < name.length(); ++i) {
if (".;[/<>".indexOf(name.charAt(i)) != -1) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must be a valid unqualified name): " + name);
}
}
return;
}
if (!Character.isJavaIdentifierStart(name.charAt(0))) {
throw new IllegalArgumentException(
"Invalid "
+ msg
+ " (must be a '<init>', '<clinit>' or a valid Java identifier): "
+ name);
}
for (int i = 1; i < name.length(); ++i) {
if (!Character.isJavaIdentifierPart(name.charAt(i))) {
throw new IllegalArgumentException(
"Invalid "
+ msg
+ " (must be '<init>' or '<clinit>' or a valid Java identifier): "
+ name);
}
}
}
/**
* Checks that the given string is a valid internal class name.
*
* @param name
* the string to be checked.
* @param msg
* a message to be used in case of error.
*/
static void checkInternalName(final String name, final String msg) {
if (name == null || name.length() == 0) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must not be null or empty)");
}
if (name.charAt(0) == '[') {
checkDesc(name, false);
} else {
checkInternalName(name, 0, -1, msg);
}
}
/**
* Checks that the given substring is a valid internal class name.
*
* @param name
* the string to be checked.
* @param start
* index of the first character of the identifier (inclusive).
* @param end
* index of the last character of the identifier (exclusive). -1
* is equivalent to <tt>name.length()</tt> if name is not
* <tt>null</tt>.
* @param msg
* a message to be used in case of error.
*/
static void checkInternalName(final String name, final int start,
final int end, final String msg) {
int max = end == -1 ? name.length() : end;
try {
int begin = start;
int slash;
do {
slash = name.indexOf('/', begin + 1);
if (slash == -1 || slash > max) {
slash = max;
}
checkIdentifier(name, begin, slash, null);
begin = slash + 1;
} while (slash != max);
} catch (IllegalArgumentException _) {
throw new IllegalArgumentException(
"Invalid "
+ msg
+ " (must be a fully qualified class name in internal form): "
+ name);
}
}
/**
* Checks that the given string is a valid type descriptor.
*
* @param desc
* the string to be checked.
* @param canBeVoid
* <tt>true</tt> if <tt>V</tt> can be considered valid.
*/
static void checkDesc(final String desc, final boolean canBeVoid) {
int end = checkDesc(desc, 0, canBeVoid);
if (end != desc.length()) {
throw new IllegalArgumentException("Invalid descriptor: " + desc);
}
}
/**
* Checks that a the given substring is a valid type descriptor.
*
* @param desc
* the string to be checked.
* @param start
* index of the first character of the identifier (inclusive).
* @param canBeVoid
* <tt>true</tt> if <tt>V</tt> can be considered valid.
* @return the index of the last character of the type decriptor, plus one.
*/
static int checkDesc(final String desc, final int start,
final boolean canBeVoid) {
if (desc == null || start >= desc.length()) {
throw new IllegalArgumentException(
"Invalid type descriptor (must not be null or empty)");
}
int index;
switch (desc.charAt(start)) {
case 'V':
if (canBeVoid) {
return start + 1;
} else {
throw new IllegalArgumentException("Invalid descriptor: "
+ desc);
}
case 'Z':
case 'C':
case 'B':
case 'S':
case 'I':
case 'F':
case 'J':
case 'D':
return start + 1;
case '[':
index = start + 1;
while (index < desc.length() && desc.charAt(index) == '[') {
++index;
}
if (index < desc.length()) {
return checkDesc(desc, index, false);
} else {
throw new IllegalArgumentException("Invalid descriptor: "
+ desc);
}
case 'L':
index = desc.indexOf(';', start);
if (index == -1 || index - start < 2) {
throw new IllegalArgumentException("Invalid descriptor: "
+ desc);
}
try {
checkInternalName(desc, start + 1, index, null);
} catch (IllegalArgumentException _) {
throw new IllegalArgumentException("Invalid descriptor: "
+ desc);
}
return index + 1;
default:
throw new IllegalArgumentException("Invalid descriptor: " + desc);
}
}
/**
* Checks that the given string is a valid method descriptor.
*
* @param desc
* the string to be checked.
*/
static void checkMethodDesc(final String desc) {
if (desc == null || desc.length() == 0) {
throw new IllegalArgumentException(
"Invalid method descriptor (must not be null or empty)");
}
if (desc.charAt(0) != '(' || desc.length() < 3) {
throw new IllegalArgumentException("Invalid descriptor: " + desc);
}
int start = 1;
if (desc.charAt(start) != ')') {
do {
if (desc.charAt(start) == 'V') {
throw new IllegalArgumentException("Invalid descriptor: "
+ desc);
}
start = checkDesc(desc, start, false);
} while (start < desc.length() && desc.charAt(start) != ')');
}
start = checkDesc(desc, start + 1, true);
if (start != desc.length()) {
throw new IllegalArgumentException("Invalid descriptor: " + desc);
}
}
/**
* Checks that the given label is not null. This method can also check that
* the label has been visited.
*
* @param label
* the label to be checked.
* @param checkVisited
* <tt>true</tt> to check that the label has been visited.
* @param msg
* a message to be used in case of error.
*/
void checkLabel(final Label label, final boolean checkVisited,
final String msg) {
if (label == null) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must not be null)");
}
if (checkVisited && labels.get(label) == null) {
throw new IllegalArgumentException("Invalid " + msg
+ " (must be visited first)");
}
}
/**
* Checks that the given label is not a label used only for debug purposes.
*
* @param label
* the label to be checked.
*/
private static void checkNonDebugLabel(final Label label) {
Field f = getLabelStatusField();
int status = 0;
try {
status = f == null ? 0 : ((Integer) f.get(label)).intValue();
} catch (IllegalAccessException e) {
throw new Error("Internal error");
}
if ((status & 0x01) != 0) {
throw new IllegalArgumentException(
"Labels used for debug info cannot be reused for control flow");
}
}
/**
* Returns the Field object corresponding to the Label.status field.
*
* @return the Field object corresponding to the Label.status field.
*/
private static Field getLabelStatusField() {
if (labelStatusField == null) {
labelStatusField = getLabelField("a");
if (labelStatusField == null) {
labelStatusField = getLabelField("status");
}
}
return labelStatusField;
}
/**
* Returns the field of the Label class whose name is given.
*
* @param name
* a field name.
* @return the field of the Label class whose name is given, or null.
*/
private static Field getLabelField(final String name) {
try {
Field f = Label.class.getDeclaredField(name);
f.setAccessible(true);
return f;
} catch (NoSuchFieldException e) {
return null;
}
}
}