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.
abstract void
printAttribute(Attribute attr)
Prints a non standard code attribute.
abstract void
printFieldInsn(int opcode, String owner, String name, String desc)
Prints a field instruction.
abstract void
printIincInsn(int var, int increment)
Prints an IINC instruction.
abstract void
printInsn(int opcode)
Prints a zero operand instruction.
abstract void
printIntInsn(int opcode, int operand)
Prints an instruction with a single int operand.
abstract void
printJumpInsn(int opcode, Label label)
Prints a jump instruction.
abstract void
printLabel(Label label)
Prints a label.
abstract void
printLdcInsn(Object cst)
Prints a LDC instruction.
abstract void
printLineNumber(int line, Label start)
Prints a line number declaration.
abstract void
printLocalVariable(String name, String desc, Label start, Label end, int index)
Prints a local variable declaration.
abstract void
printLookupSwitchInsn(Label dflt, keys[] , labels[] )
Prints a LOOKUPSWITCH instruction.
abstract void
printMaxs(int maxStack, int maxLocals)
Prints the maximum stack size and the maximum number of local variables of the method.
abstract void
printMethodInsn(int opcode, String owner, String name, String desc)
Prints a method instruction.
abstract void
printMultiANewArrayInsn(String desc, int dims)
Prints a MULTIANEWARRAY instruction.
abstract void
printTableSwitchInsn(int min, int max, Label dflt, labels[] )
Prints a TABLESWITCH instruction.
abstract void
printTryCatchBlock(Label start, Label end, Label handler, String type)
Prints a try catch block.
abstract void
printTypeInsn(int opcode, String desc)
Prints a type instruction.
abstract 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.

printAttribute

public abstract void printAttribute(Attribute attr)
Prints a non standard code attribute.
Parameters:
attr - a non standard code attribute.

printFieldInsn

public abstract 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.

printIincInsn

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

printLineNumber

public abstract 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 abstract 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 abstract void printLookupSwitchInsn(Label dflt,
                                           keys[] ,
                                           labels[] )
Prints a LOOKUPSWITCH instruction.
Parameters:
dflt - beginning of the default handler block.

printMaxs

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

printMultiANewArrayInsn

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

printVarInsn

public abstract 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