Package mockit.asm.controlFlow

Class CFGAnalysis

java.lang.Object

mockit.asm.controlFlow.CFGAnalysis

public final class CFGAnalysis
extends Object

The control flow graph analysis algorithm, used to compute the maximum stack size for a method or constructor.

A control flow graph contains one node per "basic block", and one edge per "jump" from one basic block to another. Each node (i.e., each basic block) is represented by the Label object that corresponds to the first instruction of this basic block. Each node also stores the list of its successors in the graph, as a linked list of Edge objects.

Constructor Summary

Constructors

Constructor	Description
CFGAnalysis(ConstantPoolGeneration cp, String classDesc, ByteVector code, boolean computeFrames)

Method Summary

Modifier and Type	Method	Description
@org.checkerframework.checker.index.qual.NonNegative int	computeMaxStackSize()	Control flow analysis algorithm: while the block stack is not empty, pop a block from this stack, update the max stack size, compute the true (non relative) begin stack size of the successors of this block, and push these successors onto the stack (unless they have already been pushed onto the stack).
@org.checkerframework.checker.index.qual.NonNegative int	computeMaxStackSizeFromComputedFrames()	Fix point algorithm: mark the first basic block as 'changed' (i.e. put it in the 'changed' list) and, while there are changed basic blocks, choose one, mark it as unchanged, and update its successors (which can be changed in the process).
Frame	getFirstFrame()
Label	getLabelForCurrentBasicBlock()
Label	getLabelForFirstBasicBlock()
void	updateCurrentBlockForFieldInstruction(int opcode, TypeOrMemberItem fieldItem, String fieldTypeDesc)
void	updateCurrentBlockForIINCInstruction(@org.checkerframework.checker.index.qual.NonNegative int varIndex)
void	updateCurrentBlockForInvokeInstruction(TypeOrMemberItem invokeItem, int opcode, String desc)
Label	updateCurrentBlockForJumpInstruction(int opcode, Label label)
void	updateCurrentBlockForJumpTarget(int opcode, Label nextInsn)
void	updateCurrentBlockForLabelBeforeNextInstruction(Label label)
void	updateCurrentBlockForLDCInstruction(Item constItem)
void	updateCurrentBlockForLocalVariableInstruction(int opcode, @org.checkerframework.checker.index.qual.NonNegative int varIndex)
void	updateCurrentBlockForMULTIANEWARRAYInstruction(StringItem arrayTypeItem, @org.checkerframework.checker.index.qual.NonNegative int dims)
void	updateCurrentBlockForSingleIntOperandInstruction(int opcode, int operand)
void	updateCurrentBlockForSwitchInstruction(Label dflt, Label[] caseLabels)
void	updateCurrentBlockForTypeInstruction(int opcode, StringItem typeItem)
void	updateCurrentBlockForZeroOperandInstruction(int opcode)

Methods inherited from class java.lang.Object

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

Constructor Details

CFGAnalysis

public CFGAnalysis(@NonNull
 ConstantPoolGeneration cp,
 @NonNull
 String classDesc,
 @NonNull
 ByteVector code,
 boolean computeFrames)

Method Details

getLabelForFirstBasicBlock

@NonNull
public Label getLabelForFirstBasicBlock()

getFirstFrame

public Frame getFirstFrame()

getLabelForCurrentBasicBlock

@Nullable
public Label getLabelForCurrentBasicBlock()

updateCurrentBlockForZeroOperandInstruction

public void updateCurrentBlockForZeroOperandInstruction(int opcode)

updateCurrentBlockForSingleIntOperandInstruction

public void updateCurrentBlockForSingleIntOperandInstruction(int opcode,
 int operand)

updateCurrentBlockForLocalVariableInstruction

public void updateCurrentBlockForLocalVariableInstruction(int opcode,
 @org.checkerframework.checker.index.qual.NonNegative int varIndex)

updateCurrentBlockForTypeInstruction

public void updateCurrentBlockForTypeInstruction(int opcode,
 @NonNull
 StringItem typeItem)

updateCurrentBlockForFieldInstruction

public void updateCurrentBlockForFieldInstruction(int opcode,
 @NonNull
 TypeOrMemberItem fieldItem,
 @NonNull
 String fieldTypeDesc)

updateCurrentBlockForInvokeInstruction

public void updateCurrentBlockForInvokeInstruction(@NonNull
 TypeOrMemberItem invokeItem,
 int opcode,
 @NonNull
 String desc)

updateCurrentBlockForJumpInstruction

@Nullable
public Label updateCurrentBlockForJumpInstruction(int opcode,
 @NonNull
 Label label)

updateCurrentBlockForJumpTarget

public void updateCurrentBlockForJumpTarget(int opcode,
 @Nullable
 Label nextInsn)

updateCurrentBlockForLabelBeforeNextInstruction

public void updateCurrentBlockForLabelBeforeNextInstruction(@NonNull
 Label label)

updateCurrentBlockForLDCInstruction

public void updateCurrentBlockForLDCInstruction(@NonNull
 Item constItem)

updateCurrentBlockForIINCInstruction

public void updateCurrentBlockForIINCInstruction(@org.checkerframework.checker.index.qual.NonNegative int varIndex)

updateCurrentBlockForSwitchInstruction

public void updateCurrentBlockForSwitchInstruction(@NonNull
 Label dflt,
 @NonNull
 Label[] caseLabels)

updateCurrentBlockForMULTIANEWARRAYInstruction

public void updateCurrentBlockForMULTIANEWARRAYInstruction(@NonNull
 StringItem arrayTypeItem,
 @org.checkerframework.checker.index.qual.NonNegative int dims)

computeMaxStackSizeFromComputedFrames

public @org.checkerframework.checker.index.qual.NonNegative int computeMaxStackSizeFromComputedFrames()

Fix point algorithm: mark the first basic block as 'changed' (i.e. put it in the 'changed' list) and, while there are changed basic blocks, choose one, mark it as unchanged, and update its successors (which can be changed in the process).

computeMaxStackSize

public @org.checkerframework.checker.index.qual.NonNegative int computeMaxStackSize()

Control flow analysis algorithm: while the block stack is not empty, pop a block from this stack, update the max stack size, compute the true (non relative) begin stack size of the successors of this block, and push these successors onto the stack (unless they have already been pushed onto the stack). Note: by hypothesis, the Label.inputStackTop of the blocks in the block stack are the true (non relative) beginning stack sizes of these blocks.