ASM 9.6 · org.objectweb.asm.tree.analysis.Frame

Modifier and Type	Field and Description
private static final int	MAX_STACK_SIZE The maximum size of the operand stack of any method.
private int	maxStack The maximum number of elements in the operand stack.
private int	numLocals The number of local variables of this frame.
private int	numStack The number of elements in the operand stack.
private V	returnValue The expected return type of the analyzed method, or null if the method returns void.
private V[]	values The local variables and the operand stack of this frame.

Access	Constructor and Description
public	Frame(final int the number of local variables of the frame. Long and double values are represented with two elements. numLocals, final int the maximum number of elements in the operand stack, or -1 if there is no maximum value. Long and double values are represented with a single element. maxStack) Constructs a new frame with the given size.
public	Frame(final Frame<? extends V> a frame. frame) Constructs a copy of the given Frame.

Method Summary

Modifier and Type	Method and Description
public void	clearStack() Clears the operand stack of this frame.
public void	execute(final AbstractInsnNode the instruction to execute. insn, final Interpreter<V> the interpreter to use to compute values from other values. interpreter) Simulates the execution of the given instruction on this execution stack frame.
private boolean	executeDupX2(final AbstractInsnNode insn, final V value1, final Interpreter<V> interpreter)
private void	executeInvokeInsn(final AbstractInsnNode insn, final String methodDescriptor, final Interpreter<V> interpreter)
public V	Returns: the value of the given local variable. getLocal(final int a local variable index. index) Returns the value of the given local variable.
public int	Returns: the maximum number of local variables of this frame. getLocals() Returns the maximum number of local variables of this frame.
public int	Returns: the maximum number of elements in the operand stack of this frame. getMaxStackSize() Returns the maximum number of elements in the operand stack of this frame.
public V	Returns: the value of the given operand stack slot. getStack(final int the index of an operand stack slot. index) Returns the value of the given operand stack slot.
public int	Returns: the number of elements in the operand stack of this frame. getStackSize() Returns the number of elements in the operand stack of this frame.
public Frame<V>	Returns: this frame. init(final Frame<? extends V> a frame. frame) Copies the state of the given frame into this frame.
public void	initJumpTarget(final int the opcode of the jump instruction. Can be 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, IFNONNULL, TABLESWITCH or LOOKUPSWITCH. opcode, final LabelNode a target of the jump instruction this frame corresponds to, or null if this frame corresponds to the successor of the jump instruction (i.e. the next instruction in the instructions sequence). target) Initializes a frame corresponding to the target or to the successor of a jump instruction.
public boolean	Returns: true if this frame has been changed as a result of the merge operation, or false otherwise. merge(final Frame<? extends V> a frame. This frame is left unchanged by this method. frame, final Interpreter<V> the interpreter used to merge values. interpreter) Merges the given frame into this frame.
public boolean	Returns: true if this frame has been changed as a result of the merge operation, or false otherwise. merge(final Frame<? extends V> a frame. This frame is left unchanged by this method. frame, final boolean[] the local variables that are read or written by the subroutine. The i-th element is true if and only if the local variable at index i is read or written by the subroutine. localsUsed) Merges the given frame into this frame (case of a subroutine).
public V	Returns: the value that has been popped from the stack. pop() Pops a value from the operand stack of this frame.
public void	push(final V the value that must be pushed into the stack. value) Pushes a value into the operand stack of this frame.
public void	setLocal(final int a local variable index. index, final V the new value of this local variable. value) Sets the value of the given local variable.
public void	setReturn(final V the expected return type of the analyzed method, or null if the method returns void. v) Sets the expected return type of the analyzed method.
public void	setStack(final int the index of an operand stack slot. index, final V the new value of the stack slot. value) Sets the value of the given stack slot.
public String	Returns: a string representation of this frame. toString() Overrides java.lang.Object.toString. Returns a string representation of this frame.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

MAX_STACK_SIZE	back to summary
private static final int MAX_STACK_SIZE The maximum size of the operand stack of any method.

maxStack	back to summary
private int maxStack The maximum number of elements in the operand stack. Long and double values are represented with a single element.

numLocals	back to summary
private int numLocals The number of local variables of this frame. Long and double values are represented with two elements.

numStack	back to summary
private int numStack The number of elements in the operand stack. Long and double values are represented with a single element.

returnValue	back to summary
private V returnValue The expected return type of the analyzed method, or null if the method returns void.

values	back to summary
private V[] values The local variables and the operand stack of this frame. The first `numLocals` elements correspond to the local variables. The following `numStack` elements correspond to the operand stack. Long and double values are represented with two elements in the local variables section, and with one element in the operand stack section.

Frame	back to summary
public Frame(final int numLocals, final int maxStack) Constructs a new frame with the given size. Parameters numLocals:int the number of local variables of the frame. Long and double values are represented with two elements. maxStack:int the maximum number of elements in the operand stack, or -1 if there is no maximum value. Long and double values are represented with a single element. Annotations @SuppressWarnings:unchecked

Frame	back to summary
public Frame(final Frame<? extends V> frame) Constructs a copy of the given Frame. Parameters frame:Frame<? extends V> a frame.

Method Detail

clearStack	back to summary
public void clearStack() Clears the operand stack of this frame.

execute	back to summary
public void execute(final AbstractInsnNode insn, final Interpreter<V> interpreter) throws AnalyzerException Simulates the execution of the given instruction on this execution stack frame. Parameters insn:AbstractInsnNode the instruction to execute. interpreter:Interpreter<V> the interpreter to use to compute values from other values. Exceptions AnalyzerException: if the instruction cannot be executed on this execution frame (e.g. a POP on an empty operand stack).

execute

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public void execute(final AbstractInsnNode insn, final Interpreter<V> interpreter) throws AnalyzerException

Simulates the execution of the given instruction on this execution stack frame.

Parameters

insn:AbstractInsnNode: the instruction to execute.
interpreter:Interpreter<V>: the interpreter to use to compute values from other values.

Exceptions

AnalyzerException:: if the instruction cannot be executed on this execution frame (e.g. a POP on an empty operand stack).

executeDupX2	back to summary
private boolean executeDupX2(final AbstractInsnNode insn, final V value1, final Interpreter<V> interpreter) throws AnalyzerException

executeInvokeInsn	back to summary
private void executeInvokeInsn(final AbstractInsnNode insn, final String methodDescriptor, final Interpreter<V> interpreter) throws AnalyzerException

getLocal	back to summary
public V getLocal(final int index) Returns the value of the given local variable. Long and double values are represented with two variables. Parameters index:int a local variable index. Returns:V the value of the given local variable. Exceptions IndexOutOfBoundsException: if the variable does not exist.

getLocal

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public V getLocal(final int index)

Returns the value of the given local variable. Long and double values are represented with two variables.

Parameters

index:int: a local variable index.

Returns:V

the value of the given local variable.

Exceptions

IndexOutOfBoundsException:: if the variable does not exist.

getLocals	back to summary
public int getLocals() Returns the maximum number of local variables of this frame. Long and double values are represented with two variables. Returns:int the maximum number of local variables of this frame.

getLocals

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public int getLocals()

Returns the maximum number of local variables of this frame. Long and double values are represented with two variables.

Returns:int: the maximum number of local variables of this frame.

getMaxStackSize	back to summary
public int getMaxStackSize() Returns the maximum number of elements in the operand stack of this frame. Long and double values are represented with a single element. Returns:int the maximum number of elements in the operand stack of this frame.

getMaxStackSize

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public int getMaxStackSize()

Returns the maximum number of elements in the operand stack of this frame. Long and double values are represented with a single element.

Returns:int: the maximum number of elements in the operand stack of this frame.

getStack	back to summary
public V getStack(final int index) Returns the value of the given operand stack slot. Parameters index:int the index of an operand stack slot. Returns:V the value of the given operand stack slot. Exceptions IndexOutOfBoundsException: if the operand stack slot does not exist.

getStack

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public V getStack(final int index)

Returns the value of the given operand stack slot.

Parameters

index:int: the index of an operand stack slot.

Returns:V

the value of the given operand stack slot.

Exceptions

IndexOutOfBoundsException:: if the operand stack slot does not exist.

getStackSize	back to summary
public int getStackSize() Returns the number of elements in the operand stack of this frame. Long and double values are represented with a single element. Returns:int the number of elements in the operand stack of this frame.

getStackSize

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public int getStackSize()

Returns the number of elements in the operand stack of this frame. Long and double values are represented with a single element.

Returns:int: the number of elements in the operand stack of this frame.

init	back to summary
public Frame<V> init(final Frame<? extends V> frame) Copies the state of the given frame into this frame. Parameters frame:Frame<? extends V> a frame. Returns:Frame<V> this frame.

init

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public Frame<V> init(final Frame<? extends V> frame)

Copies the state of the given frame into this frame.

Parameters

frame:Frame<? extends V>: a frame.

Returns:Frame<V>

this frame.

initJumpTarget back to summary

initJumpTarget	back to summary
public void initJumpTarget(final int opcode, final LabelNode target) Initializes a frame corresponding to the target or to the successor of a jump instruction. This method is called by `Analyzer#analyze(String, org.objectweb.asm.tree.MethodNode)` while interpreting jump instructions. It is called once for each possible target of the jump instruction, and once for its successor instruction (except for GOTO and JSR), before the frame is merged with the existing frame at this location. The default implementation of this method does nothing. Overriding this method and changing the frame values allows implementing branch-sensitive analyses. Parameters opcode:int the opcode of the jump instruction. Can be 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, IFNONNULL, TABLESWITCH or LOOKUPSWITCH. target:LabelNode a target of the jump instruction this frame corresponds to, or null if this frame corresponds to the successor of the jump instruction (i.e. the next instruction in the instructions sequence).

public void initJumpTarget(final int opcode, final LabelNode target)

Initializes a frame corresponding to the target or to the successor of a jump instruction. This method is called by Analyzer#analyze(String, org.objectweb.asm.tree.MethodNode) while interpreting jump instructions. It is called once for each possible target of the jump instruction, and once for its successor instruction (except for GOTO and JSR), before the frame is merged with the existing frame at this location. The default implementation of this method does nothing.

Overriding this method and changing the frame values allows implementing branch-sensitive analyses.

Parameters

opcode:int: the opcode of the jump instruction. Can be 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, IFNONNULL, TABLESWITCH or LOOKUPSWITCH.
target:LabelNode: a target of the jump instruction this frame corresponds to, or null if this frame corresponds to the successor of the jump instruction (i.e. the next instruction in the instructions sequence).

merge	back to summary
public boolean merge(final Frame<? extends V> frame, final Interpreter<V> interpreter) throws AnalyzerException Merges the given frame into this frame. Parameters frame:Frame<? extends V> a frame. This frame is left unchanged by this method. interpreter:Interpreter<V> the interpreter used to merge values. Returns:boolean true if this frame has been changed as a result of the merge operation, or false otherwise. Exceptions AnalyzerException: if the frames have incompatible sizes.

merge

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public boolean merge(final Frame<? extends V> frame, final Interpreter<V> interpreter) throws AnalyzerException

Merges the given frame into this frame.

Parameters

frame:Frame<? extends V>: a frame. This frame is left unchanged by this method.
interpreter:Interpreter<V>: the interpreter used to merge values.

Returns:boolean

true if this frame has been changed as a result of the merge operation, or false otherwise.

Exceptions

AnalyzerException:: if the frames have incompatible sizes.

merge	back to summary
public boolean merge(final Frame<? extends V> frame, final boolean[] localsUsed) Merges the given frame into this frame (case of a subroutine). The operand stacks are not merged, and only the local variables that have not been used by the subroutine are merged. Parameters frame:Frame<? extends V> a frame. This frame is left unchanged by this method. localsUsed:boolean[] the local variables that are read or written by the subroutine. The i-th element is true if and only if the local variable at index i is read or written by the subroutine. Returns:boolean true if this frame has been changed as a result of the merge operation, or false otherwise.

merge

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public boolean merge(final Frame<? extends V> frame, final boolean[] localsUsed)

Merges the given frame into this frame (case of a subroutine). The operand stacks are not merged, and only the local variables that have not been used by the subroutine are merged.

Parameters

frame:Frame<? extends V>: a frame. This frame is left unchanged by this method.
localsUsed:boolean[]: the local variables that are read or written by the subroutine. The i-th element is true if and only if the local variable at index i is read or written by the subroutine.

Returns:boolean

true if this frame has been changed as a result of the merge operation, or false otherwise.

pop	back to summary
public V pop() Pops a value from the operand stack of this frame. Returns:V the value that has been popped from the stack. Exceptions IndexOutOfBoundsException: if the operand stack is empty.

pop

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public V pop()

Pops a value from the operand stack of this frame.

Returns:V

the value that has been popped from the stack.

Exceptions

IndexOutOfBoundsException:: if the operand stack is empty.

push	back to summary
public void push(final V value) Pushes a value into the operand stack of this frame. Parameters value:V the value that must be pushed into the stack. Annotations @SuppressWarnings:unchecked Exceptions IndexOutOfBoundsException: if the operand stack is full.

push

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public void push(final V value)

Pushes a value into the operand stack of this frame.

Parameters

value:V: the value that must be pushed into the stack.

Annotations

@SuppressWarnings:unchecked

Exceptions

IndexOutOfBoundsException:: if the operand stack is full.

setLocal	back to summary
public void setLocal(final int index, final V value) Sets the value of the given local variable. Long and double values are represented with two variables. Parameters index:int a local variable index. value:V the new value of this local variable. Exceptions IndexOutOfBoundsException: if the variable does not exist.

setLocal

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public void setLocal(final int index, final V value)

Sets the value of the given local variable. Long and double values are represented with two variables.

Parameters

index:int: a local variable index.
value:V: the new value of this local variable.

Exceptions

IndexOutOfBoundsException:: if the variable does not exist.

setReturn	back to summary
public void setReturn(final V v) Sets the expected return type of the analyzed method. Parameters v:V the expected return type of the analyzed method, or null if the method returns void.

setReturn

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public void setReturn(final V v)

Sets the expected return type of the analyzed method.

Parameters

v:V: the expected return type of the analyzed method, or null if the method returns void.

setStack	back to summary
public void setStack(final int index, final V value) Sets the value of the given stack slot. Parameters index:int the index of an operand stack slot. value:V the new value of the stack slot. Exceptions IndexOutOfBoundsException: if the stack slot does not exist.

setStack

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public void setStack(final int index, final V value)

Sets the value of the given stack slot.

Parameters

index:int: the index of an operand stack slot.
value:V: the new value of the stack slot.

Exceptions

IndexOutOfBoundsException:: if the stack slot does not exist.

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a string representation of this frame. Returns:String a string representation of this frame. Annotations @Override

toString

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public String toString()

Overrides java.lang.Object.toString.

Returns a string representation of this frame.

Returns:String

a string representation of this frame.

Annotations

@Override

public Class Frame<V extends Value>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail