BlockCopy Class Reference

This class is used to mirror the BlockBasic objects in the fixed control-flow graph for a function. More...

#include <block.hh>

Inheritance diagram for BlockCopy:

Public Member Functions
	BlockCopy (FlowBlock *bl)
	Construct given the block to copy.
virtual FlowBlock *	subBlock (int4 i) const
	Get the i-th component block.
virtual block_type	getType (void) const
	Get the FlowBlock type of this.
virtual void	printHeader (ostream &s) const
	Print a simple description of this to stream. More...
virtual void	printTree (ostream &s, int4 level) const
	Print tree structure of any blocks owned by this. More...
virtual void	printRaw (ostream &s) const
	Print raw instructions contained in this FlowBlock.
virtual void	emit (PrintLanguage *lng) const
	Emit the instructions in this FlowBlock as structured code. More...
virtual const FlowBlock *	getExitLeaf (void) const
	Get the FlowBlock to which this block exits.
virtual PcodeOp *	lastOp (void) const
	Get the last PcodeOp executed by this FlowBlock.
virtual bool	negateCondition (bool toporbottom)
	Flip the condition computed by this. More...
virtual FlowBlock *	getSplitPoint (void)
	Get the leaf splitting block. More...
virtual bool	isComplex (void) const
	Is this too complex to be a condition (BlockCondition)
virtual void	saveXmlHeader (ostream &s) const
	Save basic information as XML attributes. More...
Public Member Functions inherited from FlowBlock
	FlowBlock (void)
	Construct a block with no edges.
virtual	~FlowBlock (void)
	Destructor.
int4	getIndex (void) const
	Get the index assigned to this block.
FlowBlock *	getParent (void)
	Get the parent FlowBlock of this.
FlowBlock *	getImmedDom (void) const
	Get the immediate dominator FlowBlock.
FlowBlock *	getCopyMap (void) const
	Get the mapped FlowBlock.
const FlowBlock *	getParent (void) const
	Get the parent FlowBlock of this.
uint4	getFlags (void) const
	Get the block_flags properties.
virtual Address	getStart (void) const
	Get the starting address of code in this FlowBlock.
virtual Address	getStop (void) const
	Get the ending address of code in this FlowBlock.
virtual void	markUnstructured (void)
	Mark target blocks of any unstructured edges.
virtual void	markLabelBumpUp (bool bump)
	Let hierarchical blocks steal labels of their (first) components. More...
virtual void	scopeBreak (int4 curexit, int4 curloopexit)
	Mark unstructured edges that should be breaks.
virtual bool	preferComplement (Funcdata &data)
	Rearrange this hierarchy to simplify boolean expressions. More...
virtual int4	flipInPlaceTest (vector< PcodeOp * > &fliplist) const
	Test normalizing the conditional branch in this. More...
virtual void	flipInPlaceExecute (void)
	Perform the flip to normalize conditional branch executed by this block. More...
virtual FlowBlock *	nextFlowAfter (const FlowBlock *bl) const
	Get the leaf FlowBlock that will execute after the given FlowBlock. More...
virtual void	orderSwitchCases (void) const
	Order case components of any contained BlockSwitch.
virtual void	restoreXmlHeader (const Element *el)
	Restore basic information for XML attributes. More...
virtual void	saveXmlBody (ostream &s) const
	Save detail about components to an XML stream.
virtual void	restoreXmlBody (List::const_iterator &iter, List::const_iterator enditer, BlockMap &resolver)
	Restore details about this FlowBlock from an XML stream. More...
void	saveXmlEdges (ostream &s) const
	Save edge information to an XML stream. More...
void	restoreXmlEdges (List::const_iterator &iter, List::const_iterator enditer, BlockMap &resolver)
	Restore edges from an XML stream. More...
void	saveXml (ostream &s) const
	Write out this to an XML stream. More...
void	restoreXml (const Element *el, BlockMap &resolver)
	Restore this from an XML stream. More...
const FlowBlock *	nextInFlow (void) const
	Return next block to be executed in flow. More...
void	setVisitCount (int4 i)
	Set the number of times this block has been visited.
int4	getVisitCount (void) const
	Get the count of visits.
void	setGotoBranch (int4 i)
	Mark a goto branch. More...
void	setDefaultSwitch (int4 i)
	Mark an edge as the switch default.
bool	isMark (void) const
	Return true if this block has been marked.
void	setMark (void)
	Mark this block.
void	clearMark (void)
	Clear any mark on this block.
void	setDonothingLoop (void)
	Label this as a do nothing loop.
void	setDead (void)
	Label this as dead.
bool	hasSpecialLabel (void) const
	Return true if this uses a different label.
bool	isJoined (void) const
	Return true if this is a joined basic block.
bool	isDuplicated (void) const
	Return true if this is a duplicated block.
void	setLoopExit (int4 i)
	Label the edge exiting this as a loop.
void	clearLoopExit (int4 i)
	Clear the loop exit edge.
void	setBackEdge (int4 i)
	Label the back edge of a loop.
bool	getFlipPath (void) const
	Have out edges been flipped.
bool	isJumpTarget (void) const
	Return true if non-fallthru jump flows into this. More...
FlowBlock *	getFalseOut (void) const
	Get the false output FlowBlock.
FlowBlock *	getTrueOut (void) const
	Get the true output FlowBlock.
FlowBlock *	getOut (int4 i)
	Get the i-th output FlowBlock.
const FlowBlock *	getOut (int4 i) const
	Get i-th output FlowBlock.
int4	getOutRevIndex (int4 i) const
	Get the input index of the i-th output FlowBlock.
FlowBlock *	getIn (int4 i)
	Get the i-th input FlowBlock.
const FlowBlock *	getIn (int4 i) const
	Get the i-th input FlowBlock.
int4	getInRevIndex (int4 i) const
	Get the output index of the i-th input FlowBlock.
const FlowBlock *	getFrontLeaf (void) const
	Get the first leaf FlowBlock. More...
FlowBlock *	getFrontLeaf (void)
	Get the first leaf FlowBlock. More...
int4	calcDepth (const FlowBlock *leaf) const
	Get the depth of the given component FlowBlock. More...
int4	sizeOut (void) const
	Get the number of out edges.
int4	sizeIn (void) const
	Get the number of in edges.
bool	hasLoopIn (void) const
	Is there a looping edge coming into this block. More...
bool	hasLoopOut (void) const
	Is there a looping edge going out of this block. More...
bool	isLoopIn (int4 i) const
	Is the i-th incoming edge a loop edge.
bool	isLoopOut (int4 i) const
	Is the i-th outgoing edge a loop edge.
int4	getInIndex (const FlowBlock *bl) const
	Get the incoming edge index for the given FlowBlock. More...
int4	getOutIndex (const FlowBlock *bl) const
	Get the outgoing edge index for the given FlowBlock. More...
bool	isDefaultBranch (int4 i) const
	Is the i-th out edge the switch default edge.
bool	isLabelBumpUp (void) const
	Are labels for this printed by the parent.
bool	isUnstructuredTarget (void) const
	Is this the target of an unstructured goto.
bool	isInteriorGotoTarget (void) const
	Is there an unstructured goto to this block's interior.
bool	hasInteriorGoto (void) const
	Is there an unstructured goto out of this block's interior.
bool	isEntryPoint (void) const
	Is the entry point of the function.
bool	isSwitchOut (void) const
	Is this a switch block.
bool	isDonothingLoop (void) const
	Is this a do nothing block.
bool	isDead (void) const
	Is this block dead.
bool	isTreeEdgeIn (int4 i) const
	Is the i-th incoming edge part of the spanning tree.
bool	isBackEdgeIn (int4 i) const
	Is the i-th incoming edge a back edge.
bool	isBackEdgeOut (int4 i) const
	Is the i-th outgoing edge a back edge.
bool	isIrreducibleOut (int4 i) const
	Is the i-th outgoing edge an irreducible edge.
bool	isIrreducibleIn (int4 i) const
	Is the i-th incoming edge an irreducible edge.
bool	isDecisionOut (int4 i) const
	Can this and the i-th output be merged into a BlockIf or BlockList.
bool	isDecisionIn (int4 i) const
	Can this and the i-th input be merged into a BlockIf or BlockList.
bool	isLoopDAGOut (int4 i) const
	Is the i-th outgoing edge part of the DAG sub-graph.
bool	isLoopDAGIn (int4 i) const
	Is the i-th incoming edge part of the DAG sub-graph.
bool	isGotoIn (int4 i) const
	Is the i-th incoming edge unstructured.
bool	isGotoOut (int4 i) const
	Is the i-th outgoing edge unstructured.
JumpTable *	getJumptable (void) const
	Get the JumpTable associated this block. More...

Private Attributes
FlowBlock *	copy
	The block being mirrored by this (usually a BlockBasic)

Additional Inherited Members
Public Types inherited from FlowBlock
enum	block_type {   t_plain, t_basic, t_graph, t_copy,   t_goto, t_multigoto, t_ls, t_condition,   t_if, t_whiledo, t_dowhile, t_switch,   t_infloop }
	The possible block types.
enum	block_flags {   f_goto_goto = 1, f_break_goto = 2, f_continue_goto = 4, f_switch_out = 0x10,   f_unstructured_targ = 0x20, f_mark = 0x80, f_mark2 = 0x100, f_entry_point = 0x200,   f_interior_gotoout = 0x400, f_interior_gotoin = 0x800, f_label_bumpup = 0x1000, f_donothing_loop = 0x2000,   f_dead = 0x4000, f_whiledo_overflow = 0x8000, f_flip_path = 0x10000, f_joined_block = 0x20000,   f_duplicate_block = 0x40000 }
	Boolean properties of blocks. More...
enum	edge_flags {   f_goto_edge = 1, f_loop_edge = 2, f_defaultswitch_edge = 4, f_irreducible = 8,   f_tree_edge = 0x10, f_forward_edge = 0x20, f_cross_edge = 0x40, f_back_edge = 0x80,   f_loop_exit_edge = 0x100 }
	Boolean properties on edges. More...
Static Public Member Functions inherited from FlowBlock
static block_type	nameToType (const string &name)
	Get the block_type associated with a name string. More...
static string	typeToName (block_type bt)
	Get the name string associated with a block_type. More...
static bool	compareBlockIndex (const FlowBlock *bl1, const FlowBlock *bl2)
	Compare FlowBlock by index. More...
static bool	compareFinalOrder (const FlowBlock *bl1, const FlowBlock *bl2)
	Final FlowBlock comparison. More...
static FlowBlock *	findCommonBlock (FlowBlock *bl1, FlowBlock *bl2)
	Find the common dominator of two FlowBlocks. More...
Protected Member Functions inherited from FlowBlock
void	setFlag (uint4 fl)
	Set a boolean property.
void	clearFlag (uint4 fl)
	Clear a boolean property.

Detailed Description

This class is used to mirror the BlockBasic objects in the fixed control-flow graph for a function.

The decompiler does control-flow structuring by making an initial copy of the control-flow graph, then iteratively collapsing nodes (in the copy) into structured nodes. So an instance of this class acts as the mirror of an original basic block within the copy of the graph. During the structuring process, an instance will start with an exact mirror of its underlying basic block's edges, but as the algorithm proceeds, edges may get replaced as neighboring basic blocks get collapsed, and eventually the instance will get collapsed itself and become a component of one of the structured block objects (BlockIf, BlockDoWhile, etc). The block that incorporates the BlockCopy as a component is accessible through getParent().

Member Function Documentation

emit()

virtual void BlockCopy::emit ( PrintLanguage *  lng ) const

inlinevirtual

Emit the instructions in this FlowBlock as structured code.

This is the main entry point, at the control-flow level, for printing structured code.

Parameters

lng	is the PrintLanguage that provides details of the high-level language being printed

Reimplemented from FlowBlock.

References PrintLanguage::emitBlockCopy().

getSplitPoint()

virtual FlowBlock* BlockCopy::getSplitPoint ( void  )

inlinevirtual

Get the leaf splitting block.

If this block ends with a conditional branch, return the deepest component block that performs the split. This component needs to be able to perform flipInPlaceTest() and flipInPlaceExecute()

Returns

the component FlowBlock or NULL if this doesn't end in a conditional branch

Reimplemented from FlowBlock.

References copy, and FlowBlock::getSplitPoint().

negateCondition()

virtual bool BlockCopy::negateCondition ( bool  toporbottom )

inlinevirtual

Flip the condition computed by this.

Flip the order of outgoing edges (at least). This should also affect the original op causing the condition. Note: we don't have to flip at all levels of the hierarchy only at the top and at the bottom

Parameters

toporbottom

is true if this is the top outermost block of the hierarchy getting negated

Returns

true if a change was made to data-flow

Reimplemented from FlowBlock.

References copy, and FlowBlock::negateCondition().

printHeader()

void BlockCopy::printHeader ( ostream &  s ) const

virtual

Print a simple description of this to stream.

Only print a header for this single block

Parameters

s	is the output stream

Reimplemented from FlowBlock.

References FlowBlock::printHeader().

printTree()

void BlockCopy::printTree ( ostream &  s, int4  level  ) const

virtual

Print tree structure of any blocks owned by this.

Recursively print out the hierarchical structure of this FlowBlock.

Parameters

s	is the output stream
level	is the current level of indentation

Reimplemented from FlowBlock.

References copy, and FlowBlock::printTree().

saveXmlHeader()

void BlockCopy::saveXmlHeader ( ostream &  s ) const

virtual

Save basic information as XML attributes.

Parameters

s	is the output stream

Reimplemented from FlowBlock.

References copy, FlowBlock::getIndex(), and FlowBlock::saveXmlHeader().

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The documentation for this class was generated from the following files:

• block.hh
• block.cc