trait ASTNode[+V <: Var[V]] extends AnyRef
Defines nodes used by statements and expressions.
- Source
- ASTNode.scala
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Abstract Value Members
- abstract def astID: Int
Each type of node is assigned a different
idto make it easily possible to do a switch over all nodes. - abstract def isSideEffectFree: Boolean
trueif the statement/expression is GUARANTEED to have no externally observable effect if it is not executed.trueif the statement/expression is GUARANTEED to have no externally observable effect if it is not executed. Sideeffect free instructions can be removed if the result of the evaluation of the expression/statement is not used. For those instructions, which may result in an exception, it has to be guaranteed that the exception is NEVER thrown. For example, a div instruction is sideeffect free if it is (statically) known that the divisor is always not equal to zero; otherwise, even if the result value is not used, the expression is not (potentially) side effect free. An array load is only side effect free if the array reference is non-null and if the index is valid.- returns
trueif the expression is GUARENTEED to have no side effect other than wasting some CPU cycles if it is not executed.
- Note
Deeply nested expressions are not supported; i.e. an expression's sub-expressions have to be Var or Const expressions. Generally, a statements expressions have to to simple expressions too - except of the Assignment statement; in the latter case the right-expression can have references to simple expressions. Hence, in case of Assignment statements the side-effect freenes is determined by the referenced expression; in all other cases the side-effect freeness is determined directly by the statement/expression.
- abstract def toCanonicalForm(implicit ev: <:<[V, DUVar[ValueInformation]]): ASTNode[DUVar[ValueInformation]]
See org.opalj.value.ValueInformation.toCanonicalForm for detail.