trait RefineDefUseUsingOrigins extends RecordDefUse
Collects/refines the abstract interpretation time definition/use information using the domain values' origin information if available.
- Self Type
- RefineDefUseUsingOrigins with Domain with TheCode with Origin
- Source
- RefineDefUseUsingOrigins.scala
- Note
ReturnAddressValues are ignored by this domain; however, the parent domain RecordDefUse has appropriate handling.
- Alphabetic
- By Inheritance
- RefineDefUseUsingOrigins
- RecordDefUse
- RecordCFG
- ReturnInstructionsDomain
- CustomInitialization
- CoreDomainFunctionality
- SubroutinesDomain
- ValuesDomain
- AnyRef
- Any
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Type Members
- trait RETValue extends Value with IsReturnAddressValue
- Definition Classes
- ValuesDomain
- trait ReferenceValue extends TypedValue[ReferenceType] with IsReferenceValue
- Definition Classes
- ValuesDomain
- class ReturnAddressValue extends RETValue
Stores a single return address (i.e., a program counter/index into the code array).
Stores a single return address (i.e., a program counter/index into the code array).
- Definition Classes
- ValuesDomain
- Note
Though the framework completely handles all aspects related to return address values, it is nevertheless necessary that this class inherits from
Value
as return addresses are stored on the stack/in the registers. However, if theValue
trait should be refined, all additional methods may – from the point-of-view of OPAL-AI – just throw anUnsupportedOperationException
as these additional methods will never be called by the OPAL-AI.
- class ReturnAddressValues extends RETValue
A collection of (not further stored) return address values.
A collection of (not further stored) return address values. Primarily used when we join the executions of subroutines.
- Definition Classes
- ValuesDomain
- trait TypedValue[+T <: Type] extends Value with KnownTypedValue
- Definition Classes
- ValuesDomain
- trait Value extends ValueInformation
Abstracts over a concrete operand stack value or a value stored in one of the local variables/registers.
Abstracts over a concrete operand stack value or a value stored in one of the local variables/registers.
Use Of Value/Dependencies On Value
In general, subclasses and users of a
Domain
should not have/declare a direct dependency onValue
. Instead they should useDomainValue
as otherwise extensibility of aDomain
may be hampered or even be impossible. The only exceptions are, of course, classes that directly inherit from this class.Refining Value
If you directly extend/refine this trait (i.e., in a subclass of the
Domain
trait you write something liketrait Value extends super.Value
), make sure that you also extend all classes/traits that inherit from this type (this may require a deep mixin composition and that you refine the typeDomainType
accordingly). However, OPAL was designed such that extending this class should – in general – not be necessary. It may also be easier to encode the desired semantics – as far as possible – as part of the domain.Implementing Value
Standard inheritance from this trait is always supported and is the primary mechanism to model an abstract domain's lattice w.r.t. some special type of value. In general, the implementation should try to avoid creating new instances of values unless strictly required to model the domain's semantics. This will greatly improve the overall performance as this framework heavily uses reference-based equality checks to speed up the evaluation.
- Definition Classes
- ValuesDomain
- Note
OPAL does not rely on any special equality semantics w.r.t. values and never directly or indirectly calls a
Value
'sequals
method. Hence, a domain can encode equality such that it best fits its need. However, some of the provided domains rely on the following semantics for equals: Two domain values have to be equal (==
) iff they represent the same information. This includes additional information, such as, the value of the origin. E.g., a value (AnIntegerValue
) that represents an arbitraryInteger
value has to returntrue
if the domain value with which it is compared also represents an arbitraryInteger
value (AnIntegerValue
). However, it may still be necessary to use multiple objects to represent an arbitrary integer value if, e.g., constraints should be attached to specific values. For example, after a comparison of an integer value with a predefined value (e.g.,AnIntegerValue < 4
) it is possible to constrain the respective value on the subsequent paths (< 4 on one path and >= 4 on the other path). To make that possible, it is however necessary to distinguish theAnIntegervalue
from some otherAnIntegerValue
to avoid constraining unrelated values.public void foo(int a,int b) { if(a < 4) { z = a - 2 // here a is constrained (< 4), b and z are unconstrained } else { z = a + 2 // here a is constrained (>= 4), b and z are unconstrained } }
In general,
equals
is only defined for values belonging to the same domain. If values need to be compared across domains, they need to be adapted to a target domain first.
- abstract type DomainIllegalValue <: (RefineDefUseUsingOrigins.this)#IllegalValue with (RefineDefUseUsingOrigins.this)#DomainValue
Abstracts over the concrete type of
IllegalValue
.Abstracts over the concrete type of
IllegalValue
.This type needs to be refined whenever the class
IllegalValue
is refined or the typeDomainValue
is refined.- Definition Classes
- ValuesDomain
- abstract type DomainReferenceValue >: Null <: (RefineDefUseUsingOrigins.this)#ReferenceValue with (RefineDefUseUsingOrigins.this)#DomainTypedValue[ReferenceType]
- Definition Classes
- ValuesDomain
- abstract type DomainReturnAddressValue <: (RefineDefUseUsingOrigins.this)#ReturnAddressValue with (RefineDefUseUsingOrigins.this)#DomainValue
Abstracts over the concrete type of
ReturnAddressValue
.Abstracts over the concrete type of
ReturnAddressValue
. Needs to be fixed by some sub-trait/sub-class. In the simplest case (i.e., when neither theValue
trait nor theReturnAddressValue
trait was refined) it is sufficient to write:type DomainReturnAddressValue = ReturnAddressValue
- Definition Classes
- ValuesDomain
- abstract type DomainReturnAddressValues <: (RefineDefUseUsingOrigins.this)#ReturnAddressValues with (RefineDefUseUsingOrigins.this)#DomainValue
- Definition Classes
- ValuesDomain
- abstract type DomainTypedValue[+T <: Type] >: Null <: (RefineDefUseUsingOrigins.this)#DomainValue
- Definition Classes
- ValuesDomain
- abstract type DomainValue >: Null <: (RefineDefUseUsingOrigins.this)#Value
Abstracts over the concrete type of
Value
.Abstracts over the concrete type of
Value
. Needs to be refined by traits that inherit fromDomain
and which extendDomain
'sValue
trait.- Definition Classes
- ValuesDomain
- type ExceptionValue = (RefineDefUseUsingOrigins.this)#DomainReferenceValue
A simple type alias of the type
DomainValue
; used to facilitate comprehension.A simple type alias of the type
DomainValue
; used to facilitate comprehension.- Definition Classes
- ValuesDomain
- type ExceptionValues = Iterable[(RefineDefUseUsingOrigins.this)#ExceptionValue]
A type alias for
Iterable
s ofExceptionValue
s; used to facilitate comprehension.A type alias for
Iterable
s ofExceptionValue
s; used to facilitate comprehension.- Definition Classes
- ValuesDomain
- type Locals = collection.mutable.Locals[(RefineDefUseUsingOrigins.this)#DomainValue]
An instruction's current register values/locals are represented using an array.
An instruction's current register values/locals are represented using an array.
- Definition Classes
- ValuesDomain
- type LocalsArray = Array[(RefineDefUseUsingOrigins.this)#Locals]
- Definition Classes
- ValuesDomain
- type Operands = List[(RefineDefUseUsingOrigins.this)#DomainValue]
An instruction's operands are represented using a list where the first element of the list represents the top level operand stack value.
An instruction's operands are represented using a list where the first element of the list represents the top level operand stack value.
- Definition Classes
- ValuesDomain
- type OperandsArray = Array[(RefineDefUseUsingOrigins.this)#Operands]
- Definition Classes
- ValuesDomain
Abstract Value Members
- abstract val DomainReferenceValueTag: ClassTag[(RefineDefUseUsingOrigins.this)#DomainReferenceValue]
The class tag can be used to create type safe arrays or to extract the concrete type of the domain value.
The class tag can be used to create type safe arrays or to extract the concrete type of the domain value.
val DomainReferenceValue(v) = value // of type "DomainValue" // v is now of the type DomainReferenceValue
- Definition Classes
- ValuesDomain
- implicit abstract val DomainValueTag: ClassTag[(RefineDefUseUsingOrigins.this)#DomainValue]
The class tag for the type
DomainValue
.The class tag for the type
DomainValue
.Required to generate instances of arrays in which values of type
DomainValue
can be stored in a type-safe manner.Initialization
In the sub-trait or class that fixes the type of
DomainValue
it is necessary to implement this abstractval
using:val DomainValueTag : ClassTag[DomainValue] = implicitly
(As of Scala 2.10 it is necessary that you do not use
implicit
in the subclass - it will compile, but fail at runtime.)- Definition Classes
- ValuesDomain
- abstract def InitializedDomainValue(origin: ValueOrigin, vi: ValueInformation): (RefineDefUseUsingOrigins.this)#DomainValue
Creates a domain value from the given value information that represents a properly domain value.
Creates a domain value from the given value information that represents a properly domain value. A representation of a proper value is created even if the value information is provided for an uninitialized value.
- Definition Classes
- ValuesDomain
- Note
This function is only defined for proper values, i.e., it is not defined for void values or illegal values.
,This method is intended to be overwritten by concrete domains which can represent more information.
- abstract def MetaInformationUpdateIllegalValue: MetaInformationUpdate[(RefineDefUseUsingOrigins.this)#DomainIllegalValue]
The result of the merge of two incompatible values has to be reported as a
MetaInformationUpdate[DomainIllegalValue]
.The result of the merge of two incompatible values has to be reported as a
MetaInformationUpdate[DomainIllegalValue]
.- Definition Classes
- ValuesDomain
- abstract def ReturnAddressValue(address: Int): (RefineDefUseUsingOrigins.this)#DomainReturnAddressValue
Factory method to create an instance of a
ReturnAddressValue
.Factory method to create an instance of a
ReturnAddressValue
.- Definition Classes
- ValuesDomain
- abstract val TheIllegalValue: (RefineDefUseUsingOrigins.this)#DomainIllegalValue
The singleton instance of the
IllegalValue
.The singleton instance of the
IllegalValue
.- Definition Classes
- ValuesDomain
- abstract val TheReturnAddressValues: (RefineDefUseUsingOrigins.this)#DomainReturnAddressValues
The singleton instance of
ReturnAddressValues
The singleton instance of
ReturnAddressValues
- Definition Classes
- ValuesDomain
- implicit abstract def classHierarchy: ClassHierarchy
This project's class hierarchy.
This project's class hierarchy.
Usually, just a redirect to the
Project
's class hierarchy or the default class hierarchy.- Definition Classes
- ValuesDomain
Concrete Value Members
- final def StructuralUpdateIllegalValue: StructuralUpdate[Nothing]
The result of merging two values should never be reported as a
StructuralUpdate
if the computed value is anIllegalValue
.The result of merging two values should never be reported as a
StructuralUpdate
if the computed value is anIllegalValue
. The JVM semantics guarantee that the value will not be used and, hence, continuing the interpretation is meaningless.- Definition Classes
- ValuesDomain
- Note
This method is solely defined for documentation purposes and to catch implementation errors early on.
- final def ValueOrigins(vo: Int): ValueOrigins
- Definition Classes
- RecordDefUse
- Annotations
- @inline()
- def abnormalExitPCs: IntTrieSet
Returns the PCs of all instructions whose execution may have led to an exception.
Returns the PCs of all instructions whose execution may have led to an exception. This can, e.g., be instance field read/field write statements or method invocations, but _in very rare cases_ also return instructions.
- Definition Classes
- RecordCFG
- def abruptMethodExecution(pc: Int, exceptionValue: (RefineDefUseUsingOrigins.this)#ExceptionValue): Unit
Called by the abstract interpreter when an exception is thrown that is not (guaranteed to be) handled within the same method.
Called by the abstract interpreter when an exception is thrown that is not (guaranteed to be) handled within the same method.
- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def abstractInterpretationEnded(aiResult: AIResult { val domain: RefineDefUseUsingOrigins.this.type }): Unit
Completes the computation of the definition/use information by using the recorded cfg.
Completes the computation of the definition/use information by using the recorded cfg.
- Definition Classes
- RecordDefUse → RecordCFG → CoreDomainFunctionality
- def afterEvaluation(pc: Int, instruction: Instruction, oldOperands: (RefineDefUseUsingOrigins.this)#Operands, oldLocals: (RefineDefUseUsingOrigins.this)#Locals, targetPC: Int, isExceptionalControlFlow: Boolean, forceJoin: Boolean, newOperands: (RefineDefUseUsingOrigins.this)#Operands, newLocals: (RefineDefUseUsingOrigins.this)#Locals): ((RefineDefUseUsingOrigins.this)#Operands, (RefineDefUseUsingOrigins.this)#Locals)
This methods is called after the evaluation of the instruction with the given
pc
with respect totargetPC
, but before the values are propagated (joined) and before it is checked whether the interpretation needs to be continued.This methods is called after the evaluation of the instruction with the given
pc
with respect totargetPC
, but before the values are propagated (joined) and before it is checked whether the interpretation needs to be continued. I.e., if the operands (newOperands
) or locals (newLocals
) are further refined then the refined operands and locals are joined (if necessary).- Definition Classes
- CoreDomainFunctionality
- Note
During the evaluation of the instruction it is possible that this method is called multiple times with different
targetPC
s. The latter is not only true for control flow instructions, but also for those instructions that may raise an exception. This method can and is intended to be overridden to further refine the operand stack/the locals. However, the overriding method should always forward the (possibly refined) operands and locals to thesuper
method (stackable traits
).
- final def allExecuted: BitSet
Computes the set of all executed instructions.
Computes the set of all executed instructions.
- Definition Classes
- RecordCFG
- def allExitPCs: IntTrieSet
Returns all PCs that may lead to the (ab)normal termination of the method.
Returns all PCs that may lead to the (ab)normal termination of the method. I.e., those instructions (in particular method call instructions, but potentially also array access instructions and (I]L)DIV|MOD instructions etc.) that may throw some unhandled exceptions will also be returned; even if the instruction may also have regular and also exception handlers!
- Definition Classes
- RecordCFG
- def allReachable(pcs: IntTrieSet): IntTrieSet
Computes the transitive hull of all instructions reachable from the given set of instructions.
Computes the transitive hull of all instructions reachable from the given set of instructions.
- Definition Classes
- RecordCFG
- def allReachable(pc: Int): IntTrieSet
Computes the transitive hull of all instructions reachable from the given instruction.
Computes the transitive hull of all instructions reachable from the given instruction.
- Definition Classes
- RecordCFG
- def allSuccessorsOf(pc: Int): PCs
Returns the set of all instructions executed after the instruction with the given
pc
.Returns the set of all instructions executed after the instruction with the given
pc
. If this set is empty, either the instruction belongs to dead code, the instruction is areturn
instruction or theinstruction
throws an exception that is never handled internally.- Definition Classes
- RecordCFG
- Note
The set is recalculated on demand.
- def areturn(pc: Int, value: (RefineDefUseUsingOrigins.this)#DomainValue): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
The given
value
, which is a value with computational type reference, is returned by the return instruction with the givenpc
.The given
value
, which is a value with computational type reference, is returned by the return instruction with the givenpc
.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def bbCFG: CFG[Instruction, Code]
- Definition Classes
- RecordCFG
- def cfgAsGraph(): DefaultMutableNode[List[Int]]
Creates a graph representation of the CFG.
Creates a graph representation of the CFG.
- Definition Classes
- RecordCFG
- Note
The returned graph is recomputed whenever this method is called.
,This implementation is for debugging purposes only. It is NOT performance optimized!
- def createDefUseGraph(code: Code): Set[DefaultMutableNode[ValueOrigin]]
Creates a multi-graph that represents the method's def-use information.
Creates a multi-graph that represents the method's def-use information. I.e., in which way a certain value is used by other instructions and where the derived values are then used by further instructions. (Basically, we compute the data-dependence graph.)
- Definition Classes
- RecordDefUse
- def dominatorTree: DominatorTree
Returns the dominator tree; see org.opalj.graphs.DominatorTree$.apply[D<:org\.opalj\.graphs\.AbstractDominatorTree]* for details regarding the properties of the dominator tree.
Returns the dominator tree; see org.opalj.graphs.DominatorTree$.apply[D<:org\.opalj\.graphs\.AbstractDominatorTree]* for details regarding the properties of the dominator tree.
- Definition Classes
- RecordCFG
- Note
To get the list of all evaluated instructions and their dominators.
val result = AI(...,...,...) val evaluated = result.evaluatedInstructions
- def dreturn(pc: Int, value: (RefineDefUseUsingOrigins.this)#DomainValue): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
The given
value
, which is a value with computational type double, is returned by the return instruction with the givenpc
.The given
value
, which is a value with computational type double, is returned by the return instruction with the givenpc
.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def dumpDefUseInfo(): Node
Creates an XHTML document that contains information about the def-/use information.
Creates an XHTML document that contains information about the def-/use information.
- Definition Classes
- RecordDefUse
- def dumpDefUseTable(): Node
Creates an XHTML table node which contains the def/use information.
Creates an XHTML table node which contains the def/use information.
- Definition Classes
- RecordDefUse
- def evaluationCompleted(pc: Int, worklist: List[Int], evaluatedPCs: IntArrayStack, operandsArray: (RefineDefUseUsingOrigins.this)#OperandsArray, localsArray: (RefineDefUseUsingOrigins.this)#LocalsArray, tracer: Option[AITracer]): Unit
Called by the framework after evaluating the instruction with the given pc.
Called by the framework after evaluating the instruction with the given pc. I.e., the state of all potential successor instructions was updated and the flow method was called – potentially multiple times – accordingly.
By default this method does nothing.
- Definition Classes
- CoreDomainFunctionality
- def exceptionHandlerSuccessorsOf(pc: Int): PCs
Returns the program counter(s) of the instruction(s) that is(are) executed next if the evaluation of this instruction may raise an exception.
Returns the program counter(s) of the instruction(s) that is(are) executed next if the evaluation of this instruction may raise an exception.
The returned set is always empty for instructions that cannot raise exceptions, such as the
StackManagementInstruction
s.- Definition Classes
- RecordCFG
- Note
The org.opalj.br.instructions.ATHROW has successors if and only if the thrown exception is directly handled inside this code block.
,The successor instructions are necessarily the handlers of catch blocks.
- def flow(currentPC: Int, currentOperands: (RefineDefUseUsingOrigins.this)#Operands, currentLocals: (RefineDefUseUsingOrigins.this)#Locals, successorPC: Int, isSuccessorScheduled: Answer, isExceptionalControlFlow: Boolean, abruptSubroutineTerminationCount: Int, wasJoinPerformed: Boolean, worklist: List[Int], operandsArray: (RefineDefUseUsingOrigins.this)#OperandsArray, localsArray: (RefineDefUseUsingOrigins.this)#LocalsArray, tracer: Option[AITracer]): List[Int]
Called by the framework after performing a computation to inform the domain about the result.
Called by the framework after performing a computation to inform the domain about the result. That is, after evaluating the effect of the instruction with
currentPC
on the current stack and register and (if necessary) joining the updated stack and registers with the stack and registers associated with the instructionsuccessorPC
. (Hence, this method is ONLY called forreturn
instructions if the return instruction throws anIllegalMonitorStateException
.) This function basically informs the domain about the instruction that may be evaluated next. The flow function is called for every possible successor of the instruction withcurrentPC
. This includes all branch targets as well as those instructions that handle exceptions.In some cases it will even be the case that
flow
is called multiple times with the same pair of program counters: (currentPC
,successorPC
). This may happen, e.g., in case of a switch instruction where multiple values have the same body/target instruction and we do not have precise information about the switch value. E.g., as in the following snippet:switch (i) { // pc: X => Y (for "1"), Y (for "2"), Y (for "3") case 1: case 2: case 3: System.out.println("Great."); // pc: Y default: System.out.println("Not So Great."); // pc: Z }
The flow function is also called after instructions that are domain independent such as
dup
andload
instructions which just manipulate the registers and stack in a generic way. This enables the domain to precisely follow the evaluation progress and in particular to perform control-flow dependent analyses.- currentPC
The program counter of the instruction that is currently evaluated by the abstract interpreter.
- currentOperands
The current operands. I.e., the operand stack before the instruction is evaluated.
- currentLocals
The current locals. I.e., the locals before the instruction is evaluated.
- successorPC
The program counter of an instruction that is a potential successor of the instruction with
currentPC
. In general the AI framework adds the pc of the successor instruction to the beginning of the worklist unless it is a join instruction. In this case the pc is added to the end – in the context of the current (sub)routine. Hence, the AI framework first evaluates all paths leading to a join instruction before the join instruction will be evaluated.- isSuccessorScheduled
Yes
if the successor instruction is or was scheduled. I.e.,Yes
is returned if the worklist containssuccessorPC
,No
if the worklist does not containsuccessorPC
.Unknown
is returned if the AI framework did not process the worklist and doesn't know anything about the scheduled successors. Note that this value is independent of the subroutine in which the value may be scheduled. If an implementation schedulessuccessorPC
the the super call has to setisSuccessorScheduled
toYes
.- isExceptionalControlFlow
true
if and only if the evaluation of the instruction with the program countercurrentPC
threw an exception;false
otherwise. Hence, if this parameter istrue
the instruction withsuccessorPC
is the first instruction of the handler.- abruptSubroutineTerminationCount
> 0
if and only if we have an exceptional control flow that terminates one or more subroutines. In this case the successor instruction is scheduled (if at all) after all subroutines that will be terminated by the exception.- wasJoinPerformed
true
if a join was performed. I.e., the successor instruction is an instruction (Code.cfJoins
) that was already previously evaluated and where multiple paths potentially join.- worklist
The current list of instructions that will be evaluated next.
If subroutines are not used (i.e., Java >= 5)
If you want to force the evaluation of the instruction with the program counter
successorPC
it is sufficient to test whether the list already containssuccessorPC
and – if not – to prepend it. If the worklist already containssuccessorPC
then the domain is allowed to move the PC to the beginning of the worklist.If the code contains subroutines (JSR/RET)
If the PC does not belong to the same (current) (sub)routine, it is not allowed to be moved to the beginning of the worklist. (Subroutines can only be found in code generated by old Java compilers; before Java 6. Subroutines are identified by jsr/ret instructions. A subroutine can be identified by going back in the worklist and by looking for specific "program counters" (e.g., SUBROUTINE_START, SUBROUTINE_END). These program counters mark the beginning of a subroutine. In other words, an instruction can be freely moved around unless a special program counter value is found. All special program counters use negative values. Additionally, neither the negative values nor the positive values between two negative values should be changed. Furthermore, no value (PC) should be put between negative values that capture subroutine information. If the domain updates the worklist, it is the responsibility of the domain to call the tracer and to inform it about the changes. Note that the worklist is not allowed to contain duplicates related to the evaluation of the current (sub-)routine.
- operandsArray
The array that associates every instruction with its operand stack that is in effect. Note, that only those elements of the array contain values that are related to instructions that were evaluated in the past; the other elements are
null
. Furthermore, it identifies theoperandsArray
of the subroutine that will execute the instruction withsuccessorPC
. The operandsArray may benull
for the current instruction (not the successor instruction) if the execution of the current instruction leads to the termination of the current subroutine. In this case the information about the operands and locals associated with all instructions belonging to the subroutine is reset.- localsArray
The array that associates every instruction with its current register values. Note, that only those elements of the array contain values that are related to instructions that were evaluated in the past. The other elements are
null
. Furthermore, it identifies thelocalsArray
of the subroutine that will execute the instruction withsuccessorPC
. The localsArray may benull
for the current instruction (not the successor instruction) if the execution of the current instruction leads to the termination of the current subroutine. In this case the information about the operands and locals associated with all instructions belonging to the subroutine is reset.- returns
The updated worklist. In most cases this is simply the given
worklist
. The default case is also to return the givenworklist
.
- Definition Classes
- RecordCFG → CoreDomainFunctionality
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- final def foreachPredecessorOf(pc: Int)(f: (PC) => Unit): Unit
- Definition Classes
- RecordCFG
- def foreachSuccessorOf(pc: Int)(f: (PC) => Unit): Unit
- Definition Classes
- RecordCFG
- def freturn(pc: Int, value: (RefineDefUseUsingOrigins.this)#DomainValue): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
The given
value
, which is a value with computational type float, is returned by the return instruction with the givenpc
.The given
value
, which is a value with computational type float, is returned by the return instruction with the givenpc
.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- final def handlesException(exceptionHandler: ExceptionHandler): Boolean
Returns
true
if the exception handler may handle at least one exception thrown by an instruction in its try block.Returns
true
if the exception handler may handle at least one exception thrown by an instruction in its try block.- Definition Classes
- RecordCFG
- final def hasMultiplePredecessors(pc: Int): Boolean
Returns
true
if the instruction with the given pc has multiple direct predecessors (more than one).Returns
true
if the instruction with the given pc has multiple direct predecessors (more than one).- Definition Classes
- RecordCFG
- final def hasMultipleSuccessors(pc: Int): Boolean
- Definition Classes
- RecordCFG
- def hasNoSuccessor(pc: Int): Boolean
- Definition Classes
- RecordCFG
- def hasSuccessor(pc: Int, regularSuccessorsOnly: Boolean, p: (Int) => Boolean): Boolean
Tests if the instruction with the given
pc
has a successor instruction with apc'
that satisfies the given predicatep
.Tests if the instruction with the given
pc
has a successor instruction with apc'
that satisfies the given predicatep
.- Definition Classes
- RecordCFG
- def infiniteLoopHeaders: IntTrieSet
Returns the first instructions of the infinite loops of the current method.
Returns the first instructions of the infinite loops of the current method. An infinite loop is a set of instructions that does not have a connection to any instruction outside of the loop (closed strongly connected component). I.e., whatever path is taken, all remaining paths will eventually include the loop header instruction. The very vast majority of methods does not have infinite loops.
- Definition Classes
- RecordCFG
- def initProperties(code: Code, cfJoins: IntTrieSet, locals: (RefineDefUseUsingOrigins.this)#Locals): Unit
Override this method to perform custom initialization steps.
Override this method to perform custom initialization steps.
Always use
abstract override
and call the super method; it is recommended to complete the initialization of this domain before calling the super method.- Definition Classes
- RecordDefUse → RecordCFG → CustomInitialization
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def ireturn(pc: Int, value: (RefineDefUseUsingOrigins.this)#DomainValue): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
The given
value
, which is a value with computational type integer, is returned by the return instruction with the givenpc
.The given
value
, which is a value with computational type integer, is returned by the return instruction with the givenpc
.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- final def isASubtypeOf(subtype: ReferenceType, supertype: ReferenceType): Answer
Tests if
subtype
is known to be subtype ofsupertype
.Tests if
subtype
is known to be subtype ofsupertype
. See org.opalj.br.ClassHierarchy'sisSubtypeOf
method for details.- Definition Classes
- ValuesDomain
- def isDirectRegularPredecessorOf(pc: Int, successorPC: Int): Boolean
- Definition Classes
- RecordCFG
- def isExitPC(pc: PC): Boolean
- Definition Classes
- RecordCFG
- def isRegularPredecessorOf(pc: Int, successorPC: Int): Boolean
Tests if the instruction with the given pc is a direct or indirect predecessor of the given successor instruction.
Tests if the instruction with the given pc is a direct or indirect predecessor of the given successor instruction.
If
pc
equalssuccessorPC
true
is returned.- Definition Classes
- RecordCFG
- Note
This method will traverse the entire graph if
successorPC
is not a regular predecessor ofpc
. Hence, consider using the(Post)DominatorTree
.
- final def isSubtypeOf(subtype: ReferenceType, supertype: ReferenceType): Boolean
Tests if
subtype
is known to be subtype ofsupertype
.Tests if
subtype
is known to be subtype ofsupertype
. See org.opalj.br.ClassHierarchy'sisSubtypeOf
method for details.- Definition Classes
- ValuesDomain
- def join(pc: Int, thisOperands: (RefineDefUseUsingOrigins.this)#Operands, thisLocals: (RefineDefUseUsingOrigins.this)#Locals, otherOperands: (RefineDefUseUsingOrigins.this)#Operands, otherLocals: (RefineDefUseUsingOrigins.this)#Locals): Update[((RefineDefUseUsingOrigins.this)#Operands, (RefineDefUseUsingOrigins.this)#Locals)]
Joins the given operand stacks and local variables.
Joins the given operand stacks and local variables.
In general there should be no need to refine this method. Overriding this method should only be done for analysis purposes.
Performance
This method heavily relies on reference comparisons to speed up the overall process of performing an abstract interpretation of a method. Hence, a computation should – whenever possible – return (one of) the original object(s) if that value has the same abstract state as the result. Furthermore, if all original values capture the same abstract state as the result of the computation, the "left" value/the value that was already used in the past should be returned.
- returns
The joined operand stack and registers. Returns
NoUpdate
if this memory layout already subsumes the other memory layout.
- Definition Classes
- CoreDomainFunctionality
- Note
The size of the operands stacks that are to be joined and the number of registers/locals that are to be joined can be expected to be identical under the assumption that the bytecode is valid and the framework contains no bugs.
,The operand stacks are guaranteed to contain compatible values w.r.t. the computational type (unless the bytecode is not valid or OPAL contains an error). I.e., if the result of joining two operand stack values is an
IllegalValue
we assume that the domain implementation is incorrect. However, the joining of two register values can result in an illegal value - which identifies the value as being dead.
- def jumpBackTargetPCs: IntTrieSet
The set of instructions to which a jump back is performed.
The set of instructions to which a jump back is performed.
- Definition Classes
- RecordCFG
- def jumpToSubroutine(pc: Int, branchTargetPC: Int, returnTargetPC: Int): Unit
- pc
The pc of the jsr(w) instruction.
- Definition Classes
- RecordCFG → SubroutinesDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def justThrowsException(pc: Int): Boolean
Returns
true
if the execution of the given instruction – identified by its pc – always just throws an exception that is (potentially) handled by the method.Returns
true
if the execution of the given instruction – identified by its pc – always just throws an exception that is (potentially) handled by the method.- Definition Classes
- RecordCFG
- def localOrigin(pc: PC, registerIndex: Int): ValueOrigins
Returns the instruction(s) which define(s) the value found in the register variable with index
registerIndex
and the program counterpc
.Returns the instruction(s) which define(s) the value found in the register variable with index
registerIndex
and the program counterpc
.- Definition Classes
- RecordDefUse
- def lreturn(pc: Int, value: (RefineDefUseUsingOrigins.this)#DomainValue): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
The given
value
, which is a value with computational type long, is returned by the return instruction with the givenpc
.The given
value
, which is a value with computational type long, is returned by the return instruction with the givenpc
.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def mergeDomainValues(pc: Int, v1: (RefineDefUseUsingOrigins.this)#DomainValue, v2: (RefineDefUseUsingOrigins.this)#DomainValue): (RefineDefUseUsingOrigins.this)#DomainValue
Merges the given domain value
v1
with the domain valuev2
and returns the merged value which isv1
ifv1
is an abstraction ofv2
,v2
ifv2
is an abstraction ofv1
or some other value if a new value is computed that abstracts over both values.Merges the given domain value
v1
with the domain valuev2
and returns the merged value which isv1
ifv1
is an abstraction ofv2
,v2
ifv2
is an abstraction ofv1
or some other value if a new value is computed that abstracts over both values.This operation is commutative.
- Definition Classes
- ValuesDomain
- def normalExitPCs: IntTrieSet
Returns the PCs of all return instructions which may have returned normally; which are practically always all return instructions unless the analysis _really_ finds an unbalanced return; which is very unlikely.
Returns the PCs of all return instructions which may have returned normally; which are practically always all return instructions unless the analysis _really_ finds an unbalanced return; which is very unlikely.
- Definition Classes
- RecordCFG
- def operandOrigin(pc: PC, stackIndex: Int): ValueOrigins
Returns the instruction(s) which defined the value used by the instruction with the given
pc
and which is stored at the stack position with the given stackIndex.Returns the instruction(s) which defined the value used by the instruction with the given
pc
and which is stored at the stack position with the given stackIndex. The first/top value on the stack has index 0 and the second value - if it exists - has index two; independent of the computational category of the values.- Definition Classes
- RecordDefUse
- def pdtBasedControlDependencies: DominanceFrontiers
Computes the control dependencies graph based on the post dominator tree.
Computes the control dependencies graph based on the post dominator tree.
Internally, a post dominator tree is used for methods without infinite loops; i.e., we compute non-termination insensitive control dependencies. Note that – dues to exceptions which may lead to abnormal returns
- Definition Classes
- RecordCFG
- def postDominatorTree: PostDominatorTree
Returns the org.opalj.graphs.PostDominatorTree (PDT).
Returns the org.opalj.graphs.PostDominatorTree (PDT).
- Definition Classes
- RecordCFG
- Note
The construction of
,PostDominatorTree
s for methods with multiple exit nodes and also – potentially - infinite loops has several limitations; in particular, if the results are used for computing control-dependence information.If the method/CFG contains infinite loops (see #infiniteLoopHeaders) then the instructions which jump back to the infinite loop headers (from within the loop) are also used as additional exit nodes.
- def predecessorsOf(pc: Int): PCs
Returns the program counter(s) of the instruction(s) that is(are) executed before the instruction with the given pc.
Returns the program counter(s) of the instruction(s) that is(are) executed before the instruction with the given pc.
If the instruction with the given
pc
was never executed an empty set is returned.- pc
A valid program counter.
- Definition Classes
- RecordCFG
- def properties(pc: Int, propertyToString: (AnyRef) => String): Option[String]
Prints out the information by which values the current values are used.
Prints out the information by which values the current values are used.
Returns a string representation of the properties associated with the instruction with the respective program counter.
Associating properties with an instruction and maintaining those properties is, however, at the sole responsibility of the
Domain
.This method is predefined to facilitate the development of support tools and is not used by the abstract interpretation framework.
Domain
s that define (additional) properties should (abstract
)override
this method and should return a textual representation of the property.- Definition Classes
- RecordDefUse → ValuesDomain
- def regularSuccessorsOf(pc: Int): PCs
Returns the program counter(s) of the instruction(s) that is(are) executed next if the evaluation of this instruction may succeed without raising an exception.
Returns the program counter(s) of the instruction(s) that is(are) executed next if the evaluation of this instruction may succeed without raising an exception.
The returned set is always empty for
return
instructions. It is also empty for instructions that always throw an exception (e.g., an integer value that is divided by zero will always result in a NullPointException.)- Definition Classes
- RecordCFG
- Note
The org.opalj.br.instructions.ATHROW instruction will never have a
regularSuccessor
. Thereturn
instructions will never have any successors.
- def returnFromSubroutine(pc: Int, lvIndex: Int): Unit
- pc
The pc of the ret instruction.
- Definition Classes
- SubroutinesDomain
- def returnVoid(pc: Int): Computation[Nothing, (RefineDefUseUsingOrigins.this)#ExceptionValue]
Called when a return instruction with the given
pc
is reached.Called when a return instruction with the given
pc
is reached. In other words, when the method returns normally.- Definition Classes
- RecordCFG → ReturnInstructionsDomain
- Note
If another domain always overrides this method the invocation of this one has to be ensured; otherwise the recorded CFG will be incomplete.
- def safeExternalExceptionsUsedBy(pc: Int): ValueOrigins
Returns the instructions which use the (external) exception raised by the instruction with the given ValueOrigin.
Returns the instructions which use the (external) exception raised by the instruction with the given ValueOrigin.
- Definition Classes
- RecordDefUse
- def safeUsedBy(valueOrigin: ValueOrigin): ValueOrigins
Returns the instructions which use the value or the external exception identified by the given value origin.
Returns the instructions which use the value or the external exception identified by the given value origin. Basically, the same as
usedBy
except that an empty set of value origins is returned if the instruction with the given value origin is dead.- Definition Classes
- RecordDefUse
- def subroutineStartPCs: PCs
Returns the PCs of the first instructions of all subroutines; that is, the instructions a
JSR
instruction jumps to.Returns the PCs of the first instructions of all subroutines; that is, the instructions a
JSR
instruction jumps to.- Definition Classes
- RecordCFG
- final def successorsOf(pc: Int, regularSuccessorOnly: Boolean): PCs
- Definition Classes
- RecordCFG
- def summarize(pc: Int, values: Iterable[(RefineDefUseUsingOrigins.this)#DomainValue]): (RefineDefUseUsingOrigins.this)#DomainValue
Creates a summary of the given domain values by summarizing and joining the given
values
.Creates a summary of the given domain values by summarizing and joining the given
values
. For the precise details regarding the calculation of a summary seeValue.summarize(...)
.- pc
The program counter that will be used for the summary value if a new value is returned that abstracts over/summarizes the given values.
- values
An
Iterable
over one or more values.
- Definition Classes
- ValuesDomain
- Note
The current algorithm is generic and should satisfy most needs, but it is not very efficient. However, it should be easy to tailor it for a specific domain/domain values, if need be.
- def throwsException(pc: Int): Boolean
Returns
true
if the execution of the given instruction – identified by its pc – ex-/implicitly throws an exception that is (potentially) handled by the method.Returns
true
if the execution of the given instruction – identified by its pc – ex-/implicitly throws an exception that is (potentially) handled by the method.- Definition Classes
- RecordCFG
- def unused: ValueOrigins
Returns the union of the set of unused parameters and the set of all instructions which compute a value that is not used in the following.
Returns the union of the set of unused parameters and the set of all instructions which compute a value that is not used in the following.
- Definition Classes
- RecordDefUse
- def updateMemoryLayout(oldValue: (RefineDefUseUsingOrigins.this)#DomainValue, newValue: (RefineDefUseUsingOrigins.this)#DomainValue, operands: (RefineDefUseUsingOrigins.this)#Operands, locals: (RefineDefUseUsingOrigins.this)#Locals): ((RefineDefUseUsingOrigins.this)#Operands, (RefineDefUseUsingOrigins.this)#Locals)
Replaces all occurrences of
oldValue
(using reference-quality) withnewValue
.Replaces all occurrences of
oldValue
(using reference-quality) withnewValue
. If no occurrences are found, the original operands and locals data structures are returned.- Definition Classes
- CoreDomainFunctionality
- def usedBy(valueOrigin: ValueOrigin): ValueOrigins
Returns the instructions which use the value or the external exception identified by the given value origin.
Returns the instructions which use the value or the external exception identified by the given value origin. In case of external exceptions thrown by an instruction, the pc of the value origin pc is
ai.underlyingPC(valueOrigin)
- Definition Classes
- RecordDefUse
- final def wasExecuted(pc: Int): Boolean
Returns
true
if the instruction with the givenpc
was executed.Returns
true
if the instruction with the givenpc
was executed.- Definition Classes
- RecordCFG