org.logicalcobwebs.asm.util
Class CheckCodeAdapter

java.lang.Object
  org.logicalcobwebs.asm.CodeAdapter
      org.logicalcobwebs.asm.util.CheckCodeAdapter

All Implemented Interfaces:

CodeVisitor

public class CheckCodeAdapter
extends CodeAdapter

A CodeAdapter that checks that its methods are properly used. More precisely this code adapter checks each instruction individually (i.e., each visit method checks some preconditions based only on its arguments - such as the fact that the given opcode is correct for a given visit method), but does not check the sequence of instructions. For example, in a method whose signature is void m (), the invalid instruction IRETURN, or the invalid sequence IADD L2I will not be detected by this code adapter.

Field Summary

private boolean	end true if the visitMaxs method has been called.
private java.util.HashMap	labels The already visited labels.
private static int[]	TYPE Code of the visit method to be used for each opcode.

Fields inherited from class org.logicalcobwebs.asm.CodeAdapter

cv

Constructor Summary

CheckCodeAdapter(CodeVisitor cv)
Constructs a new CheckCodeAdapter object.

Method Summary

(package private) static void	checkConstant(java.lang.Object cst) Checks that the given value is an Integer, a Float, a Long, a Double or a String.
(package private) static void	checkDesc(java.lang.String desc, boolean canBeVoid) Checks that the given string is a valid type descriptor.
(package private) static int	checkDesc(java.lang.String desc, int start, boolean canBeVoid) Checks that a the given substring is a valid type descriptor.
(package private) void	checkEnd() Checks that the visitMaxs method has not been called.
(package private) static void	checkIdentifier(java.lang.String name, int start, int end, java.lang.String msg) Checks that the given substring is a valid Java identifier.
(package private) static void	checkIdentifier(java.lang.String name, java.lang.String msg) Checks that the given string is a valid Java identifier.
(package private) static void	checkInternalName(java.lang.String name, int start, int end, java.lang.String msg) Checks that the given substring is a valid internal class name.
(package private) static void	checkInternalName(java.lang.String name, java.lang.String msg) Checks that the given string is a valid internal class name.
(package private) void	checkLabel(Label label, boolean checkVisited, java.lang.String msg) Checks that the given label is not null.
(package private) static void	checkMethodDesc(java.lang.String desc) Checks that the given string is a valid method descriptor.
(package private) static void	checkMethodIdentifier(java.lang.String name, java.lang.String msg) Checks that the given string is a valid Java identifier or is equal to '<init>' or '<clinit>'.
(package private) static void	checkOpcode(int opcode, int type) Checks that the type of the given opcode is equal to the given type.
(package private) static void	checkSignedByte(int value, java.lang.String msg) Checks that the given value is a signed byte.
(package private) static void	checkSignedShort(int value, java.lang.String msg) Checks that the given value is a signed short.
(package private) static void	checkUnsignedShort(int value, java.lang.String msg) Checks that the given value is an unsigned short.
void	visitAttribute(Attribute attr) Visits a non standard attribute of the code.
void	visitFieldInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc) Visits a field instruction.
void	visitIincInsn(int var, int increment) Visits an IINC instruction.
void	visitInsn(int opcode) Visits a zero operand instruction.
void	visitIntInsn(int opcode, int operand) Visits an instruction with a single int operand.
void	visitJumpInsn(int opcode, Label label) Visits a jump instruction.
void	visitLabel(Label label) Visits a label.
void	visitLdcInsn(java.lang.Object cst) Visits a LDC instruction.
void	visitLineNumber(int line, Label start) Visits a line number declaration.
void	visitLocalVariable(java.lang.String name, java.lang.String desc, Label start, Label end, int index) Visits a local variable declaration.
void	visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) Visits a LOOKUPSWITCH instruction.
void	visitMaxs(int maxStack, int maxLocals) Visits the maximum stack size and the maximum number of local variables of the method.
void	visitMethodInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc) Visits a method instruction.
void	visitMultiANewArrayInsn(java.lang.String desc, int dims) Visits a MULTIANEWARRAY instruction.
void	visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels) Visits a TABLESWITCH instruction.
void	visitTryCatchBlock(Label start, Label end, Label handler, java.lang.String type) Visits a try catch block.
void	visitTypeInsn(int opcode, java.lang.String desc) Visits a type instruction.
void	visitVarInsn(int opcode, int var) Visits a local variable instruction.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

end

private boolean end

true if the visitMaxs method has been called.

labels

private java.util.HashMap labels

The already visited labels. This map associate Integer values to Label keys.

TYPE

private static final int[] TYPE

Code of the visit method to be used for each opcode.

Constructor Detail

CheckCodeAdapter

public CheckCodeAdapter(CodeVisitor cv)

Constructs a new CheckCodeAdapter object.

Parameters:

cv - the code visitor to which this adapter must delegate calls.

Method Detail

visitInsn

public void visitInsn(int opcode)

Description copied from interface: CodeVisitor

Visits a zero operand instruction.

Specified by:

visitInsn in interface CodeVisitor

Overrides:

visitInsn in class CodeAdapter

Parameters:

opcode - the opcode of the instruction to be visited. This opcode is either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER, or MONITOREXIT.

visitIntInsn

public void visitIntInsn(int opcode,
                         int operand)

Description copied from interface: CodeVisitor

Visits an instruction with a single int operand.

Specified by:

visitIntInsn in interface CodeVisitor

Overrides:

visitIntInsn in class CodeAdapter

Parameters:

opcode - the opcode of the instruction to be visited. This opcode is either BIPUSH, SIPUSH or NEWARRAY.

operand - the operand of the instruction to be visited.

visitVarInsn

public void visitVarInsn(int opcode,
                         int var)

Description copied from interface: CodeVisitor

Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.

Specified by:

visitVarInsn in interface CodeVisitor

Overrides:

visitVarInsn in class CodeAdapter

Parameters:

opcode - the opcode of the local variable instruction to be visited. This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.

var - the operand of the instruction to be visited. This operand is the index of a local variable.

visitTypeInsn

public void visitTypeInsn(int opcode,
                          java.lang.String desc)

Description copied from interface: CodeVisitor

Visits a type instruction. A type instruction is an instruction that takes a type descriptor as parameter.

Specified by:

visitTypeInsn in interface CodeVisitor

Overrides:

visitTypeInsn in class CodeAdapter

Parameters:

opcode - the opcode of the type instruction to be visited. This opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.

desc - the operand of the instruction to be visited. This operand is must be a fully qualified class name in internal form, or the type descriptor of an array type (see Type).

visitFieldInsn

public void visitFieldInsn(int opcode,
                           java.lang.String owner,
                           java.lang.String name,
                           java.lang.String desc)

Description copied from interface: CodeVisitor

Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.

Specified by:

visitFieldInsn in interface CodeVisitor

Overrides:

visitFieldInsn in class CodeAdapter

Parameters:

opcode - the opcode of the type instruction to be visited. This opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.

owner - the internal name of the field's owner class (see getInternalName).

name - the field's name.

desc - the field's descriptor (see Type).

visitMethodInsn

public void visitMethodInsn(int opcode,
                            java.lang.String owner,
                            java.lang.String name,
                            java.lang.String desc)

Description copied from interface: CodeVisitor

Visits a method instruction. A method instruction is an instruction that invokes a method.

Specified by:

visitMethodInsn in interface CodeVisitor

Overrides:

visitMethodInsn in class CodeAdapter

Parameters:

opcode - the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or INVOKEINTERFACE.

owner - the internal name of the method's owner class (see getInternalName).

name - the method's name.

desc - the method's descriptor (see Type).

visitJumpInsn

public void visitJumpInsn(int opcode,
                          Label label)

Description copied from interface: CodeVisitor

Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.

Specified by:

visitJumpInsn in interface CodeVisitor

Overrides:

visitJumpInsn in class CodeAdapter

Parameters:

opcode - the opcode of the type instruction to be visited. This opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.

label - the operand of the instruction to be visited. This operand is a label that designates the instruction to which the jump instruction may jump.

visitLabel

public void visitLabel(Label label)

Description copied from interface: CodeVisitor

Visits a label. A label designates the instruction that will be visited just after it.

Specified by:

visitLabel in interface CodeVisitor

Overrides:

visitLabel in class CodeAdapter

Parameters:

label - a Label object.

visitLdcInsn

public void visitLdcInsn(java.lang.Object cst)

Description copied from interface: CodeVisitor

Visits a LDC instruction.

Specified by:

visitLdcInsn in interface CodeVisitor

Overrides:

visitLdcInsn in class CodeAdapter

Parameters:

cst - the constant to be loaded on the stack. This parameter must be a non null Integer, a Float, a Long, a Double or a String.

visitIincInsn

public void visitIincInsn(int var,
                          int increment)

Description copied from interface: CodeVisitor

Visits an IINC instruction.

Specified by:

visitIincInsn in interface CodeVisitor

Overrides:

visitIincInsn in class CodeAdapter

Parameters:

var - index of the local variable to be incremented.

increment - amount to increment the local variable by.

visitTableSwitchInsn

public void visitTableSwitchInsn(int min,
                                 int max,
                                 Label dflt,
                                 Label[] labels)

Description copied from interface: CodeVisitor

Visits a TABLESWITCH instruction.

Specified by:

visitTableSwitchInsn in interface CodeVisitor

Overrides:

visitTableSwitchInsn in class CodeAdapter

Parameters:

min - the minimum key value.

max - the maximum key value.

dflt - beginning of the default handler block.

labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the min + i key.

visitLookupSwitchInsn

public void visitLookupSwitchInsn(Label dflt,
                                  int[] keys,
                                  Label[] labels)

Description copied from interface: CodeVisitor

Visits a LOOKUPSWITCH instruction.

Specified by:

visitLookupSwitchInsn in interface CodeVisitor

Overrides:

visitLookupSwitchInsn in class CodeAdapter

Parameters:

dflt - beginning of the default handler block.

keys - the values of the keys.

labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the keys[i] key.

visitMultiANewArrayInsn

public void visitMultiANewArrayInsn(java.lang.String desc,
                                    int dims)

Description copied from interface: CodeVisitor

Visits a MULTIANEWARRAY instruction.

Specified by:

visitMultiANewArrayInsn in interface CodeVisitor

Overrides:

visitMultiANewArrayInsn in class CodeAdapter

Parameters:

desc - an array type descriptor (see Type).

dims - number of dimensions of the array to allocate.

visitTryCatchBlock

public void visitTryCatchBlock(Label start,
                               Label end,
                               Label handler,
                               java.lang.String type)

Description copied from interface: CodeVisitor

Visits a try catch block.

Specified by:

visitTryCatchBlock in interface CodeVisitor

Overrides:

visitTryCatchBlock in class CodeAdapter

Parameters:

start - beginning of the exception handler's scope (inclusive).

end - end of the exception handler's scope (exclusive).

handler - beginning of the exception handler's code.

type - internal name of the type of exceptions handled by the handler, or null to catch any exceptions (for "finally" blocks).

visitMaxs

public void visitMaxs(int maxStack,
                      int maxLocals)

Description copied from interface: CodeVisitor

Visits the maximum stack size and the maximum number of local variables of the method.

Specified by:

visitMaxs in interface CodeVisitor

Overrides:

visitMaxs in class CodeAdapter

Parameters:

maxStack - maximum stack size of the method.

maxLocals - maximum number of local variables for the method.

visitLocalVariable

public void visitLocalVariable(java.lang.String name,
                               java.lang.String desc,
                               Label start,
                               Label end,
                               int index)

Description copied from interface: CodeVisitor

Visits a local variable declaration.

Specified by:

visitLocalVariable in interface CodeVisitor

Overrides:

visitLocalVariable in class CodeAdapter

Parameters:

name - the name of a local variable.

desc - the type descriptor of this local variable.

start - the first instruction corresponding to the scope of this local variable (inclusive).

end - the last instruction corresponding to the scope of this local variable (exclusive).

index - the local variable's index.

visitLineNumber

public void visitLineNumber(int line,
                            Label start)

Description copied from interface: CodeVisitor

Visits a line number declaration.

Specified by:

visitLineNumber in interface CodeVisitor

Overrides:

visitLineNumber in class CodeAdapter

Parameters:

line - a line number. This number refers to the source file from which the class was compiled.

start - the first instruction corresponding to this line number.

visitAttribute

public void visitAttribute(Attribute attr)

Description copied from interface: CodeVisitor

Visits a non standard attribute of the code. This method must visit only the first attribute in the given attribute list.

Specified by:

visitAttribute in interface CodeVisitor

Overrides:

visitAttribute in class CodeAdapter

Parameters:

attr - a non standard code attribute. Must not be null.

checkEnd

void checkEnd()

Checks that the visitMaxs method has not been called.

checkOpcode

static void checkOpcode(int opcode,
                        int type)

Checks that the type of the given opcode is equal to the given type.

Parameters:

opcode - the opcode to be checked.

type - the expected opcode type.

checkSignedByte

static void checkSignedByte(int value,
                            java.lang.String msg)

Checks that the given value is a signed byte.

Parameters:

value - the value to be checked.

msg - an message to be used in case of error.

checkSignedShort

static void checkSignedShort(int value,
                             java.lang.String msg)

Checks that the given value is a signed short.

Parameters:

value - the value to be checked.

msg - an message to be used in case of error.

checkUnsignedShort

static void checkUnsignedShort(int value,
                               java.lang.String msg)

Checks that the given value is an unsigned short.

Parameters:

value - the value to be checked.

msg - an message to be used in case of error.

checkConstant

static void checkConstant(java.lang.Object cst)

Checks that the given value is an Integer, a Float, a Long, a Double or a String.

Parameters:

cst - the value to be checked.

checkIdentifier

static void checkIdentifier(java.lang.String name,
                            java.lang.String msg)

Checks that the given string is a valid Java identifier.

Parameters:

name - the string to be checked.

msg - a message to be used in case of error.

checkIdentifier

static void checkIdentifier(java.lang.String name,
                            int start,
                            int end,
                            java.lang.String msg)

Checks that the given substring is a valid Java identifier.

Parameters:

name - the string to be checked.

start - index of the first character of the identifier (inclusive).

end - index of the last character of the identifier (exclusive). -1 is equivalent to name.length() if name is not null.

msg - a message to be used in case of error.

checkMethodIdentifier

static void checkMethodIdentifier(java.lang.String name,
                                  java.lang.String msg)

Checks that the given string is a valid Java identifier or is equal to '<init>' or '<clinit>'.

Parameters:

name - the string to be checked.

msg - a message to be used in case of error.

checkInternalName

static void checkInternalName(java.lang.String name,
                              java.lang.String msg)

Checks that the given string is a valid internal class name.

Parameters:

name - the string to be checked.

msg - a message to be used in case of error.

checkInternalName

static void checkInternalName(java.lang.String name,
                              int start,
                              int end,
                              java.lang.String msg)

Checks that the given substring is a valid internal class name.

Parameters:

name - the string to be checked.

start - index of the first character of the identifier (inclusive).

end - index of the last character of the identifier (exclusive). -1 is equivalent to name.length() if name is not null.

msg - a message to be used in case of error.

checkDesc

static void checkDesc(java.lang.String desc,
                      boolean canBeVoid)

Checks that the given string is a valid type descriptor.

Parameters:

desc - the string to be checked.

canBeVoid - true if V can be considered valid.

checkDesc

static int checkDesc(java.lang.String desc,
                     int start,
                     boolean canBeVoid)

Checks that a the given substring is a valid type descriptor.

Parameters:

desc - the string to be checked.

start - index of the first character of the identifier (inclusive).

canBeVoid - true if V can be considered valid.

Returns:

the index of the last character of the type decriptor, plus one.

checkMethodDesc

static void checkMethodDesc(java.lang.String desc)

Checks that the given string is a valid method descriptor.

Parameters:

desc - the string to be checked.

checkLabel

void checkLabel(Label label,
                boolean checkVisited,
                java.lang.String msg)

Checks that the given label is not null. This method can also check that the label has been visited.

Parameters:

label - the label to be checked.

checkVisited - true to check that the label has been visited.

msg - a message to be used in case of error.