BlockIf Class Reference

A basic "if" block. More...

#include <block.hh>

Inheritance diagram for BlockIf:

Public Member Functions
	BlockIf (void)
	Constructor.
void	setGotoTarget (FlowBlock *bl)
	Mark the target of the unstructured edge.
FlowBlock *	getGotoTarget (void) const
	Get the target of the unstructured edge.
uint4	getGotoType (void) const
	Get the type of unstructured edge.
virtual block_type	getType (void) const
	Get the FlowBlock type of this.
virtual void	markUnstructured (void)
	Mark target blocks of any unstructured edges.
virtual void	scopeBreak (int4 curexit, int4 curloopexit)
	Mark unstructured edges that should be breaks.
virtual void	printHeader (ostream &s) const
	Print a simple description of this to stream. More...
virtual void	emit (PrintLanguage *lng) const
	Emit the instructions in this FlowBlock as structured code. More...
virtual bool	preferComplement (Funcdata &data)
	Rearrange this hierarchy to simplify boolean expressions. 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 FlowBlock *	nextFlowAfter (const FlowBlock *bl) const
	Get the leaf FlowBlock that will execute after the given FlowBlock. More...
virtual void	saveXmlBody (ostream &s) const
	Save detail about components to an XML stream.
Public Member Functions inherited from BlockGraph
void	clear (void)
	Clear all component FlowBlock objects.
virtual	~BlockGraph (void)
	Destructor.
const vector< FlowBlock * > &	getList (void) const
	Get the list of component FlowBlock objects.
int4	getSize (void) const
	Get the number of components.
FlowBlock *	getBlock (int4 i) const
	Get the i-th component.
virtual FlowBlock *	subBlock (int4 i) const
	Get the i-th component block.
virtual void	markLabelBumpUp (bool bump)
	Let hierarchical blocks steal labels of their (first) components. 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	finalizePrinting (const Funcdata &data) const
	Make any final configurations necessary to print the block.
virtual void	restoreXmlBody (List::const_iterator &iter, List::const_iterator enditer, BlockMap &resolver)
	Restore details about this FlowBlock from an XML stream. More...
void	restoreXml (const Element *el, const AddrSpaceManager *m)
	Restore this BlockGraph from an XML stream. More...
void	addEdge (FlowBlock *begin, FlowBlock *end)
	Add a directed edge between component FlowBlocks. More...
void	addLoopEdge (FlowBlock *begin, int4 outindex)
	Mark a given edge as a loop edge. More...
void	removeEdge (FlowBlock *begin, FlowBlock *end)
	Remove an edge between component FlowBlocks. More...
void	switchEdge (FlowBlock *in, FlowBlock *outbefore, FlowBlock *outafter)
	Move an edge from one out FlowBlock to another. More...
void	moveOutEdge (FlowBlock *blold, int4 slot, FlowBlock *blnew)
	Move indicated out edge to a new FlowBlock. More...
void	removeBlock (FlowBlock *bl)
	Remove a FlowBlock from this BlockGraph. More...
void	removeFromFlow (FlowBlock *bl)
	Remove given FlowBlock preserving flow in this. More...
void	removeFromFlowSplit (FlowBlock *bl, bool flipflow)
	Remove FlowBlock splitting flow between input and output edges. More...
void	spliceBlock (FlowBlock *bl)
	Splice given FlowBlock together with its output. More...
void	setStartBlock (FlowBlock *bl)
	Set the entry point FlowBlock for this graph. More...
FlowBlock *	getStartBlock (void) const
	Get the entry point FlowBlock. More...
FlowBlock *	newBlock (void)
	Build a new plain FlowBlock. More...
BlockBasic *	newBlockBasic (Funcdata *fd)
	Build a new BlockBasic. More...
BlockCopy *	newBlockCopy (FlowBlock *bl)
	Build a new BlockCopy. More...
BlockGoto *	newBlockGoto (FlowBlock *bl)
	Build a new BlockGoto. More...
BlockMultiGoto *	newBlockMultiGoto (FlowBlock *bl, int4 outedge)
	Build a new BlockMultiGoto. More...
BlockList *	newBlockList (const vector< FlowBlock * > &nodes)
	Build a new BlockList. More...
BlockCondition *	newBlockCondition (FlowBlock *b1, FlowBlock *b2)
	Build a new BlockCondition. More...
BlockIf *	newBlockIfGoto (FlowBlock *cond)
	Build a new BlockIfGoto. More...
BlockIf *	newBlockIf (FlowBlock *cond, FlowBlock *tc)
	Build a new BlockIf. More...
BlockIf *	newBlockIfElse (FlowBlock *cond, FlowBlock *tc, FlowBlock *fc)
	Build a new BlockIfElse. More...
BlockWhileDo *	newBlockWhileDo (FlowBlock *cond, FlowBlock *cl)
	Build a new BlockWhileDo. More...
BlockFor *	newBlockFor (FlowBlock *cond, FlowBlock *cl)
	Build a new BlockFor. More...
BlockDoWhile *	newBlockDoWhile (FlowBlock *condcl)
	Build a new BlockDoWhile. More...
BlockInfLoop *	newBlockInfLoop (FlowBlock *body)
	Build a new BlockInfLoop. More...
BlockSwitch *	newBlockSwitch (const vector< FlowBlock * > &cs, bool hasExit)
	Build a new BlockSwitch. More...
void	orderBlocks (void)
void	buildCopy (const BlockGraph &graph)
	Build a copy of a BlockGraph. More...
void	clearVisitCount (void)
	Clear the visit count in all node FlowBlocks.
void	calcForwardDominator (const vector< FlowBlock * > &rootlist)
	Calculate forward dominators. More...
void	buildDomTree (vector< vector< FlowBlock * > > &child) const
	Build the dominator tree. More...
int4	buildDomDepth (vector< int4 > &depth) const
	Calculate dominator depths. More...
void	buildDomSubTree (vector< FlowBlock * > &res, FlowBlock *root) const
	Collect nodes from a dominator sub-tree. More...
void	calcLoop (void)
	Calculate loop edges. More...
void	collectReachable (vector< FlowBlock * > &res, FlowBlock *bl, bool un) const
	Collect reachable/unreachable FlowBlocks from a given start FlowBlock. More...
void	structureLoops (vector< FlowBlock * > &rootlist)
	Label loop edges. 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 bool	negateCondition (bool toporbottom)
	Flip the condition computed by this. More...
virtual FlowBlock *	getSplitPoint (void)
	Get the leaf splitting block. 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 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...
virtual void	restoreXmlHeader (const Element *el)
	Restore basic information for XML attributes. 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...
bool	dominates (const FlowBlock *subBlock) const
	Does this block dominate the given block. More...
bool	restrictedByConditional (const FlowBlock *cond) const
	Check if the condition from the given block holds for this block. 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
uint4	gototype
	The type of unstructured edge (if present)
FlowBlock *	gototarget
	The target FlowBlock of the unstructured edge (if present)

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, t_for }
	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...
static FlowBlock *	findCommonBlock (const vector< FlowBlock * > &blockSet)
	Find common dominator of multiple FlowBlocks. More...
Protected Member Functions inherited from BlockGraph
void	swapBlocks (int4 i, int4 j)
	Swap the positions two component FlowBlocks. More...
Protected Member Functions inherited from FlowBlock
void	setFlag (uint4 fl)
	Set a boolean property.
void	clearFlag (uint4 fl)
	Clear a boolean property.
Static Protected Member Functions inherited from BlockGraph
static void	markCopyBlock (FlowBlock *bl, uint4 fl)
	Set properties on the first leaf FlowBlock. More...

Detailed Description

A basic "if" block.

This represents a formal "if" structure in code, with a expression for the condition, and one or two bodies of the conditionally executed code. An instance has one, two, or three components. One component is always the conditional block. If there is a second component, it is the block of code executed when the condition is true. If there is a third component, it is the "else" block, executed when the condition is false.

If there is only one component, this represents the case where the conditionally executed branch is unstructured. This is generally emitted where the conditionally executed body is the single goto statement.

A BlockIf will always have at most one (structured) exit edge. With one component, one of the edges of the conditional component is unstructured. With two components, one of the conditional block edges flows to the body block, and the body's out edge and the remaining conditional block out edge flow to the same exit block. With three components, the one conditional edge flows to the true body block, the other conditional edge flows to the false body block, and outgoing edges from the body blocks, if they exist, flow to the same exit block.

Member Function Documentation

virtual void BlockIf::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 BlockGraph.

References PrintLanguage::emitBlockIf().

FlowBlock * BlockIf::nextFlowAfter ( const FlowBlock *  bl ) const

virtual

Get the leaf FlowBlock that will execute after the given FlowBlock.

Within the hierarchy of this FlowBlock, assume the given FlowBlock will fall-thru in its execution at some point. Return the first leaf block (BlockBasic or BlockCopy) that will execute after the given FlowBlock completes, assuming this is a unique block.

Parameters

bl	is the given FlowBlock

Returns

the next FlowBlock to execute or NULL

Reimplemented from BlockGraph.

References FlowBlock::nextFlowAfter().

bool BlockIf::preferComplement ( Funcdata &  data )

virtual

Rearrange this hierarchy to simplify boolean expressions.

For the instructions in this block, decide if the control-flow structure can be rearranged so that boolean expressions come out more naturally.

Parameters

data	is the function to analyze

Returns

true if a change was made

Reimplemented from FlowBlock.

References FlowBlock::flipInPlaceExecute(), FlowBlock::flipInPlaceTest(), FlowBlock::getSplitPoint(), and opFlipInPlaceExecute().

void BlockIf::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().

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

• block.hh
• block.cc