org.objectweb.asm.util

Class PrintCodeVisitor

Implemented Interfaces:
CodeVisitor
Known Direct Subclasses:
ASMifierCodeVisitor, TraceCodeVisitor

public abstract class PrintCodeVisitor
extends Object
implements CodeVisitor

An abstract code visitor that prints the code it visits. Each visitXXX method clears the buf buffer, calls the corresponding printXXX method, and then adds the buffer's content to the text list. In order to provide a concrete print code visitor, one must implement the printXXX methods in a sub class of this class. Each method should print the instructions it visits in buf.

Author:
Eric Bruneton, Eugene Kuleshov

Field Summary

static String[]
OPCODES
The names of the Java Virtual Machine opcodes.
protected StringBuffer
buf
A buffer used to convert instructions to strings.
protected List
text
The text to be printed.

Constructor Summary

PrintCodeVisitor()
Constructs a new PrintCodeVisitor object.

Method Summary

List
getText()
Returns the code printed by this code visitor.
void
printAttribute(Attribute attr)
Prints a non standard code attribute.
void
printFieldInsn(int opcode, String owner, String name, String desc)
Prints a field instruction.
void
printIincInsn(int var, int increment)
Prints an IINC instruction.
void
printInsn(int opcode)
Prints a zero operand instruction.
void
printIntInsn(int opcode, int operand)
Prints an instruction with a single int operand.
void
printJumpInsn(int opcode, Label label)
Prints a jump instruction.
void
printLabel(Label label)
Prints a label.
void
printLdcInsn(Object cst)
Prints a LDC instruction.
void
printLineNumber(int line, Label start)
Prints a line number declaration.
void
printLocalVariable(String name, String desc, Label start, Label end, int index)
Prints a local variable declaration.
void
printLookupSwitchInsn(Label dflt, keys[] , labels[] )
Prints a LOOKUPSWITCH instruction.
void
printMaxs(int maxStack, int maxLocals)
Prints the maximum stack size and the maximum number of local variables of the method.
void
printMethodInsn(int opcode, String owner, String name, String desc)
Prints a method instruction.
void
printMultiANewArrayInsn(String desc, int dims)
Prints a MULTIANEWARRAY instruction.
void
printTableSwitchInsn(int min, int max, Label dflt, labels[] )
Prints a TABLESWITCH instruction.
void
printTryCatchBlock(Label start, Label end, Label handler, String type)
Prints a try catch block.
void
printTypeInsn(int opcode, String desc)
Prints a type instruction.
void
printVarInsn(int opcode, int var)
Prints a local variable instruction.
void
visitAttribute(Attribute attr)
void
visitFieldInsn(int opcode, String owner, String name, String desc)
void
visitIincInsn(int var, int increment)
void
visitInsn(int opcode)
void
visitIntInsn(int opcode, int operand)
void
visitJumpInsn(int opcode, Label label)
void
visitLabel(Label label)
void
visitLdcInsn(Object cst)
void
visitLineNumber(int line, Label start)
void
visitLocalVariable(String name, String desc, Label start, Label end, int index)
void
visitLookupSwitchInsn(Label dflt, keys[] , labels[] )
void
visitMaxs(int maxStack, int maxLocals)
void
visitMethodInsn(int opcode, String owner, String name, String desc)
void
visitMultiANewArrayInsn(String desc, int dims)
void
visitTableSwitchInsn(int min, int max, Label dflt, labels[] )
void
visitTryCatchBlock(Label start, Label end, Label handler, String type)
void
visitTypeInsn(int opcode, String desc)
void
visitVarInsn(int opcode, int var)

Field Details

OPCODES

public static final String[] OPCODES
The names of the Java Virtual Machine opcodes.


buf

protected final StringBuffer buf
A buffer used to convert instructions to strings.


text

protected final List text

Constructor Details

PrintCodeVisitor

protected PrintCodeVisitor()

Method Details

getText

public List getText()
Returns the code printed by this code visitor.

Returns:
the code printed by this code visitor. See text.


printAttribute

public void printAttribute(Attribute attr)
Prints a non standard code attribute.

Parameters:
attr - a non standard code attribute.


printFieldInsn

public void printFieldInsn(int opcode,
                           String owner,
                           String name,
                           String desc)
Prints a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.

Parameters:
opcode - the opcode of the type instruction to be printed. 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).


printIincInsn

public void printIincInsn(int var,
                          int increment)
Prints an IINC instruction.

Parameters:
var - index of the local variable to be incremented.
increment - amount to increment the local variable by.


printInsn

public void printInsn(int opcode)
Prints a zero operand instruction.

Parameters:
opcode - the opcode of the instruction to be printed. 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.


printIntInsn

public void printIntInsn(int opcode,
                         int operand)
Prints an instruction with a single int operand.

Parameters:
opcode - the opcode of the instruction to be printed. This opcode is either BIPUSH, SIPUSH or NEWARRAY.
operand - the operand of the instruction to be printed.


printJumpInsn

public void printJumpInsn(int opcode,
                          Label label)
Prints a jump instruction. A jump instruction is an instruction that may jump to another instruction.

Parameters:
opcode - the opcode of the type instruction to be printed. 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 printed. This operand is a label that designates the instruction to which the jump instruction may jump.


printLabel

public void printLabel(Label label)
Prints a label. A label designates the instruction that will be visited just after it.

Parameters:
label - a Label object.


printLdcInsn

public void printLdcInsn(Object cst)
Prints a LDC instruction.

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.


printLineNumber

public void printLineNumber(int line,
                            Label start)
Prints a line number declaration.

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.


printLocalVariable

public void printLocalVariable(String name,
                               String desc,
                               Label start,
                               Label end,
                               int index)
Prints a local variable declaration.

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.


printLookupSwitchInsn

public void printLookupSwitchInsn(Label dflt,
                                  keys[] ,
                                  labels[] )
Prints a LOOKUPSWITCH instruction.

Parameters:
dflt - beginning of the default handler block.


printMaxs

public void printMaxs(int maxStack,
                      int maxLocals)
Prints the maximum stack size and the maximum number of local variables of the method.

Parameters:
maxStack - maximum stack size of the method.
maxLocals - maximum number of local variables for the method.


printMethodInsn

public void printMethodInsn(int opcode,
                            String owner,
                            String name,
                            String desc)
Prints a method instruction. A method instruction is an instruction that invokes a method.

Parameters:
opcode - the opcode of the type instruction to be printed. 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).


printMultiANewArrayInsn

public void printMultiANewArrayInsn(String desc,
                                    int dims)
Prints a MULTIANEWARRAY instruction.

Parameters:
desc - an array type descriptor (see Type).
dims - number of dimensions of the array to allocate.


printTableSwitchInsn

public void printTableSwitchInsn(int min,
                                 int max,
                                 Label dflt,
                                 labels[] )
Prints a TABLESWITCH instruction.

Parameters:
min - the minimum key value.
max - the maximum key value.
dflt - beginning of the default handler block.


printTryCatchBlock

public void printTryCatchBlock(Label start,
                               Label end,
                               Label handler,
                               String type)
Prints a try catch block.

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).


printTypeInsn

public void printTypeInsn(int opcode,
                          String desc)
Prints a type instruction. A type instruction is an instruction that takes a type descriptor as parameter.

Parameters:
opcode - the opcode of the type instruction to be printed. This opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
desc - the operand of the instruction to be printed. This operand is must be a fully qualified class name in internal form, or a the type descriptor of an array type (see Type).


printVarInsn

public void printVarInsn(int opcode,
                         int var)
Prints a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.

Parameters:
opcode - the opcode of the local variable instruction to be printed. This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
var - the operand of the instruction to be printed. This operand is the index of a local variable.


visitAttribute

public void visitAttribute(Attribute attr)
Specified by:
visitAttribute in interface CodeVisitor


visitFieldInsn

public void visitFieldInsn(int opcode,
                           String owner,
                           String name,
                           String desc)
Specified by:
visitFieldInsn in interface CodeVisitor


visitIincInsn

public void visitIincInsn(int var,
                          int increment)
Specified by:
visitIincInsn in interface CodeVisitor


visitInsn

public void visitInsn(int opcode)
Specified by:
visitInsn in interface CodeVisitor


visitIntInsn

public void visitIntInsn(int opcode,
                         int operand)
Specified by:
visitIntInsn in interface CodeVisitor


visitJumpInsn

public void visitJumpInsn(int opcode,
                          Label label)
Specified by:
visitJumpInsn in interface CodeVisitor


visitLabel

public void visitLabel(Label label)
Specified by:
visitLabel in interface CodeVisitor


visitLdcInsn

public void visitLdcInsn(Object cst)
Specified by:
visitLdcInsn in interface CodeVisitor


visitLineNumber

public void visitLineNumber(int line,
                            Label start)
Specified by:
visitLineNumber in interface CodeVisitor


visitLocalVariable

public void visitLocalVariable(String name,
                               String desc,
                               Label start,
                               Label end,
                               int index)
Specified by:
visitLocalVariable in interface CodeVisitor


visitLookupSwitchInsn

public void visitLookupSwitchInsn(Label dflt,
                                  keys[] ,
                                  labels[] )
Specified by:
visitLookupSwitchInsn in interface CodeVisitor


visitMaxs

public void visitMaxs(int maxStack,
                      int maxLocals)
Specified by:
visitMaxs in interface CodeVisitor


visitMethodInsn

public void visitMethodInsn(int opcode,
                            String owner,
                            String name,
                            String desc)
Specified by:
visitMethodInsn in interface CodeVisitor


visitMultiANewArrayInsn

public void visitMultiANewArrayInsn(String desc,
                                    int dims)
Specified by:
visitMultiANewArrayInsn in interface CodeVisitor


visitTableSwitchInsn

public void visitTableSwitchInsn(int min,
                                 int max,
                                 Label dflt,
                                 labels[] )
Specified by:
visitTableSwitchInsn in interface CodeVisitor


visitTryCatchBlock

public void visitTryCatchBlock(Label start,
                               Label end,
                               Label handler,
                               String type)
Specified by:
visitTryCatchBlock in interface CodeVisitor


visitTypeInsn

public void visitTypeInsn(int opcode,
                          String desc)
Specified by:
visitTypeInsn in interface CodeVisitor


visitVarInsn

public void visitVarInsn(int opcode,
                         int var)
Specified by:
visitVarInsn in interface CodeVisitor