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Static Public Member Functions | Private Member Functions | Private Attributes | List of all members
retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal Class Referencefinal

A CFG traversal that checks whether a variable is modified prior to every read access to it starting from a given statement. More...

#include <modified_before_read_cfg_traversal.h>

Inheritance diagram for retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal:
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Collaboration diagram for retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal:
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Static Public Member Functions

static bool isModifiedBeforeEveryRead (ShPtr< Variable > var, ShPtr< Statement > startStmt, ShPtr< CFG > cfg, ShPtr< ValueAnalysis > va, ShPtr< CallInfoObtainer > cio)
 Returns true if the given variable var is modified prior to every read access to it in cfg, starting from startStmt. More...
 

Private Member Functions

 ModifiedBeforeReadCFGTraversal (ShPtr< Variable > var, ShPtr< CFG > cfg, ShPtr< ValueAnalysis > va, ShPtr< CallInfoObtainer > cio)
 Constructs a new traverser. More...
 
virtual bool visitStmt (ShPtr< Statement > stmt) override
 Visits the given statement stmt. More...
 
virtual bool getEndRetVal () const override
 Returns the value that should be returned when an end of the traversal is reached. More...
 
virtual bool combineRetVals (bool origRetVal, bool newRetVal) const override
 Computes a new return value from the original return value (origRetVal) and the new return value (newRetVal). More...
 

Private Attributes

ShPtr< Variablevar
 Variable whose modification is looked for. More...
 
ShPtr< ValueAnalysisva
 Analysis of values. More...
 
ShPtr< CallInfoObtainercio
 Obtainer of information about function calls. More...
 
bool wasModifiedBeforeEveryRead
 Was the variable modified before every read? More...
 

Additional Inherited Members

- Protected Member Functions inherited from retdec::llvmir2hll::CFGTraversal
 CFGTraversal (ShPtr< CFG > cfg, bool defaultCurrRetVal)
 Constructs a new traverser. More...
 
 ~CFGTraversal ()=default
 
bool getCurrRetVal () const
 Returns the value that should be returned as the result of visiting a statement. More...
 
bool performTraversal (ShPtr< Statement > startStmt)
 Performs a traversal of the current CFG, starting at startStmt. More...
 
bool performTraversalFromSuccessors (ShPtr< Statement > stmt)
 Performs a traversal of the current CFG, starting at the successor(s) of stmt. More...
 
bool performReverseTraversal (ShPtr< Statement > startStmt)
 Performs a reverse traversal of the current CFG, starting at startStmt. More...
 
bool performReverseTraversalFromPredecessors (ShPtr< Statement > stmt)
 Performs a reverse traversal of the current CFG, starting at the predecessor(s) of stmt. More...
 
- Protected Attributes inherited from retdec::llvmir2hll::CFGTraversal
ShPtr< CFGcfg
 CFG that is being traversed. More...
 
StmtUSet checkedStmts
 Statements that have been checked (to prevent looping). More...
 
bool currRetVal
 Current return value of visitStmt(). More...
 
bool stopTraversal
 Should the traversal be stopped? More...
 

Detailed Description

A CFG traversal that checks whether a variable is modified prior to every read access to it starting from a given statement.

Instances of this class have reference object semantics. This is a concrete traverser which should not be subclassed.

Constructor & Destructor Documentation

◆ ModifiedBeforeReadCFGTraversal()

retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::ModifiedBeforeReadCFGTraversal ( ShPtr< Variable var,
ShPtr< CFG cfg,
ShPtr< ValueAnalysis va,
ShPtr< CallInfoObtainer cio 
)
private

Constructs a new traverser.

See the description of isModifiedBeforeEveryRead() for information on the parameters.

Member Function Documentation

◆ combineRetVals()

bool retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::combineRetVals ( bool  origRetVal,
bool  newRetVal 
) const
overrideprivatevirtual

Computes a new return value from the original return value (origRetVal) and the new return value (newRetVal).

Implements retdec::llvmir2hll::CFGTraversal.

◆ getEndRetVal()

bool retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::getEndRetVal ( ) const
overrideprivatevirtual

Returns the value that should be returned when an end of the traversal is reached.

For example, the end may mean the end node of the CFG or a statement that has already been traversed.

Implements retdec::llvmir2hll::CFGTraversal.

◆ isModifiedBeforeEveryRead()

bool retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::isModifiedBeforeEveryRead ( ShPtr< Variable var,
ShPtr< Statement startStmt,
ShPtr< CFG cfg,
ShPtr< ValueAnalysis va,
ShPtr< CallInfoObtainer cio 
)
static

Returns true if the given variable var is modified prior to every read access to it in cfg, starting from startStmt.

Parameters
[in]varVariable whose modification is looked for.
[in]startStmtStatement from which the traversal should start.
[in]cfgCFG that should be traversed.
[in]vaAnalysis of values.
[in]cioObtainer of information about function calls.
Preconditions
  • var, stmt, cfg, va are non-null
  • va is in a valid state
  • cio is initialized

This function leaves va in a valid state.

If the variable is not modified at all, this function also returns false.

◆ visitStmt()

bool retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::visitStmt ( ShPtr< Statement stmt)
overrideprivatevirtual

Visits the given statement stmt.

return true if the traversing should continue, false otherwise.

Note: checkedStmts is modified in CFGTraversal, so it is not necessary for the implementation of this function to add stmt to checkedStmts.

If you want the traversal to end prematurely, set the stopTraversal variable to true. Otherwise, if you just return false, the traversal may still continue from other branches because of recursion.

Implements retdec::llvmir2hll::CFGTraversal.

Member Data Documentation

◆ cio

ShPtr<CallInfoObtainer> retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::cio
private

Obtainer of information about function calls.

◆ va

ShPtr<ValueAnalysis> retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::va
private

Analysis of values.

◆ var

ShPtr<Variable> retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::var
private

Variable whose modification is looked for.

◆ wasModifiedBeforeEveryRead

bool retdec::llvmir2hll::ModifiedBeforeReadCFGTraversal::wasModifiedBeforeEveryRead
private

Was the variable modified before every read?


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