Package serp.bytecode
Class SwitchInstruction
- java.lang.Object
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- serp.bytecode.Instruction
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- serp.bytecode.JumpInstruction
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- serp.bytecode.SwitchInstruction
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- All Implemented Interfaces:
BCEntity
,InstructionPtr
,VisitAcceptor
public abstract class SwitchInstruction extends JumpInstruction
Contains functionality common to the different switch types (TableSwitch and LookupSwitch).- Author:
- Eric Lindauer
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Constructor Summary
Constructors Constructor Description SwitchInstruction(Code owner, int opcode)
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description SwitchInstruction
addCase(int match, Instruction target)
Add a case to this switch.abstract SwitchInstruction
addMatch(int match)
SwitchInstruction
addTarget(Instruction target)
Add a target to this switch.int
countTargets()
int
getDefaultOffset()
Synonymous withJumpInstruction.getOffset()
.Instruction
getDefaultTarget()
Synonymous withJumpInstruction.getTarget()
.abstract int[]
getMatches()
int[]
getOffsets()
Returns the current byte offsets for the different switch cases in this Instruction.int
getStackChange()
Return the number of stack positions this instruction pushes or pops during its execution.Instruction[]
getTargets()
Return the targets for this switch, or empty array if not set.void
replaceTarget(Instruction oldTarget, Instruction newTarget)
Replace the given old, likely invalid, target with a new target.SwitchInstruction
setCases(int[] matches, Instruction[] targets)
Set the match-jumppt pairs for this switch.SwitchInstruction
setDefaultOffset(int offset)
Synonymous withJumpInstruction.setOffset(int)
.SwitchInstruction
setDefaultTarget(Instruction ins)
Synonymous withJumpInstruction.setTarget(serp.bytecode.Instruction)
.SwitchInstruction
setMatches(int[] matches)
void
setOffsets(int[] offsets)
Sets the offsets for the instructions representing the different switch statement cases.SwitchInstruction
setTargets(Instruction[] targets)
Set the jump points for this switch.void
updateTargets()
Use the byte indexes read from the class file to calculate and set references to the target instruction(s) for this ptr.-
Methods inherited from class serp.bytecode.JumpInstruction
acceptVisit, equalsInstruction, getOffset, getTarget, setOffset, setTarget
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Methods inherited from class serp.bytecode.Instruction
getByteIndex, getClassLoader, getCode, getLineNumber, getLogicalStackChange, getName, getOpcode, getPool, getProject, isValid
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface serp.bytecode.InstructionPtr
getCode
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Constructor Detail
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SwitchInstruction
public SwitchInstruction(Code owner, int opcode)
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Method Detail
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getOffsets
public int[] getOffsets()
Returns the current byte offsets for the different switch cases in this Instruction.
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setOffsets
public void setOffsets(int[] offsets)
Sets the offsets for the instructions representing the different switch statement cases. WARNING: these offsets will not be changed in the event that the code is modified following this call. It is typically a good idea to follow this call with a call to updateTargets as soon as the instructions at the given offsets are valid, at which point the Instructions themselves will be used as the targets and the offsets will be updated as expected.
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countTargets
public int countTargets()
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getDefaultTarget
public Instruction getDefaultTarget()
Synonymous withJumpInstruction.getTarget()
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getDefaultOffset
public int getDefaultOffset()
Synonymous withJumpInstruction.getOffset()
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setDefaultOffset
public SwitchInstruction setDefaultOffset(int offset)
Synonymous withJumpInstruction.setOffset(int)
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setDefaultTarget
public SwitchInstruction setDefaultTarget(Instruction ins)
Synonymous withJumpInstruction.setTarget(serp.bytecode.Instruction)
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getTargets
public Instruction[] getTargets()
Return the targets for this switch, or empty array if not set.
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setTargets
public SwitchInstruction setTargets(Instruction[] targets)
Set the jump points for this switch.- Returns:
- this instruction, for method chaining
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addTarget
public SwitchInstruction addTarget(Instruction target)
Add a target to this switch.- Returns:
- this instruction, for method chaining
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getStackChange
public int getStackChange()
Description copied from class:Instruction
Return the number of stack positions this instruction pushes or pops during its execution.- Overrides:
getStackChange
in classInstruction
- Returns:
- 0 if the stack is not affected by this instruction, a positive number if it pushes onto the stack, and a negative number if it pops from the stack
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updateTargets
public void updateTargets()
Description copied from interface:InstructionPtr
Use the byte indexes read from the class file to calculate and set references to the target instruction(s) for this ptr. This method will be called after the byte code has been read in for the first time and before it is written after modification.- Specified by:
updateTargets
in interfaceInstructionPtr
- Overrides:
updateTargets
in classJumpInstruction
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replaceTarget
public void replaceTarget(Instruction oldTarget, Instruction newTarget)
Description copied from interface:InstructionPtr
Replace the given old, likely invalid, target with a new target. The new target Instruction is guaranteed to be in the same code block as this InstructionPtr.- Specified by:
replaceTarget
in interfaceInstructionPtr
- Overrides:
replaceTarget
in classJumpInstruction
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setCases
public SwitchInstruction setCases(int[] matches, Instruction[] targets)
Set the match-jumppt pairs for this switch.- Returns:
- this instruction, for method chaining
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setMatches
public SwitchInstruction setMatches(int[] matches)
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addCase
public SwitchInstruction addCase(int match, Instruction target)
Add a case to this switch.- Returns:
- this instruction, for method chaining
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addMatch
public abstract SwitchInstruction addMatch(int match)
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getMatches
public abstract int[] getMatches()
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