Package it.unive.lisa.program.cfg.statement

Class Assignment

java.lang.Object

it.unive.lisa.program.cfg.statement.Statement

it.unive.lisa.program.cfg.statement.Expression

it.unive.lisa.program.cfg.statement.BinaryExpression

it.unive.lisa.program.cfg.statement.Assignment

All Implemented Interfaces:

ProgramPoint, CodeElement, Node<Statement,Edge,CFG>, java.lang.Comparable<Statement>

public class Assignment
extends BinaryExpression

A statement assigning the result of an expression to an assignable expression.

Field Summary

Fields inherited from class it.unive.lisa.program.cfg.statement.Statement

offset

Constructor Summary

Constructors

Constructor	Description
Assignment(CFG cfg, CodeLocation location, Expression target, Expression expression)	Builds the assignment, assigning expression to target, happening at the given location in the program.

Method Summary

Modifier and Type	Method	Description
<A extends AbstractState<A,H,V>,H extends HeapDomain<H>,V extends ValueDomain<V>> AnalysisState<A,H,V>	semantics(AnalysisState<A,H,V> entryState, InterproceduralAnalysis<A,H,V> interprocedural, StatementStore<A,H,V> expressions)	Semantics of an assignment (left = right) is evaluated as follows: the semantic of the right is evaluated using the given entryState, returning a new analysis state as_r = <state_r, expr_r> the semantic of the left is evaluated using as_r, returning a new analysis state as_l = <state_l, expr_l> the final post-state is evaluated through AnalysisState.assign(Identifier, SymbolicExpression, ProgramPoint), using expr_l as id and expr_r as value This means that all side effects from right are evaluated before the ones from left. Computes the semantics of the statement, expressing how semantic information is transformed by the execution of this statement.
java.lang.String	toString()

Methods inherited from class it.unive.lisa.program.cfg.statement.BinaryExpression

accept, equals, getLeft, getRight, hashCode, setOffset

Methods inherited from class it.unive.lisa.program.cfg.statement.Expression

getDynamicType, getMetaVariables, getParentStatement, getRootStatement, getRuntimeTypes, getStaticType, setParentStatement, setRuntimeTypes

Methods inherited from class it.unive.lisa.program.cfg.statement.Statement

compareTo, getCFG, getLocation, getOffset, stopsExecution, throwsError

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Assignment

public Assignment(CFG cfg,
                  CodeLocation location,
                  Expression target,
                  Expression expression)

Builds the assignment, assigning expression to target, happening at the given location in the program.

Parameters:

cfg - the cfg that this statement belongs to

location - the location where this statement is defined within the source file. If unknown, use null

target - the target of the assignment

expression - the expression to assign to target

Method Detail

toString

public final java.lang.String toString()

Specified by:

toString in class Statement

semantics

public final <A extends AbstractState<A,H,V>,H extends HeapDomain<H>,V extends ValueDomain<V>> AnalysisState<A,H,V> semantics(AnalysisState<A,H,V> entryState,
                                                                                                                                                                  InterproceduralAnalysis<A,H,V> interprocedural,
                                                                                                                                                                  StatementStore<A,H,V> expressions)
                                                                                                                                                           throws SemanticException

Semantics of an assignment (left = right) is evaluated as follows:

1. the semantic of the right is evaluated using the given entryState, returning a new analysis state as_r = <state_r, expr_r>
2. the semantic of the left is evaluated using as_r, returning a new analysis state as_l = <state_l, expr_l>
3. the final post-state is evaluated through AnalysisState.assign(Identifier, SymbolicExpression, ProgramPoint), using expr_l as id and expr_r as value

This means that all side effects from right are evaluated before the ones from left.

Computes the semantics of the statement, expressing how semantic information is transformed by the execution of this statement. This method is also responsible for recursively invoking the Statement.semantics(AnalysisState, InterproceduralAnalysis, StatementStore) of each nested Expression, saving the result of each call in expressions.

Specified by:

semantics in class Statement

Type Parameters:

A - the type of AbstractState

H - the type of the HeapDomain

V - the type of the ValueDomain

Parameters:

entryState - the entry state that represents the abstract values of each program variable and memory location when the execution reaches this statement

interprocedural - the interprocedural analysis of the program to analyze

expressions - the cache where analysis states of intermediate expressions must be stored

Returns:

the AnalysisState representing the abstract result of the execution of this statement

Throws:

SemanticException - if something goes wrong during the computation