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io.joern.javasrc2cpg.astcreation.expressions.AstForLambdasCreator.scala Maven / Gradle / Ivy
package io.joern.javasrc2cpg.astcreation.expressions
import com.github.javaparser.ast.expr.LambdaExpr
import com.github.javaparser.ast.stmt.{BlockStmt, Statement}
import com.github.javaparser.resolution.declarations.ResolvedMethodDeclaration
import com.github.javaparser.resolution.types.parametrization.ResolvedTypeParametersMap
import com.github.javaparser.resolution.types.{ResolvedReferenceType, ResolvedType, ResolvedTypeVariable}
import io.joern.javasrc2cpg.astcreation.expressions.AstForLambdasCreator.{
ClosureBindingEntry,
LambdaBody,
LambdaImplementedInfo
}
import io.joern.javasrc2cpg.astcreation.{AstCreator, ExpectedType}
import io.joern.javasrc2cpg.scope.Scope.ScopeVariable
import io.joern.javasrc2cpg.typesolvers.TypeInfoCalculator.{ObjectMethodSignatures, TypeConstants}
import io.joern.javasrc2cpg.util.BindingTable.createBindingTable
import io.joern.javasrc2cpg.util.Util.{composeMethodFullName, composeMethodLikeSignature, composeUnresolvedSignature}
import io.joern.javasrc2cpg.util.{BindingTable, BindingTableAdapterForLambdas, LambdaBindingInfo, NameConstants}
import io.joern.x2cpg.utils.AstPropertiesUtil.*
import io.joern.x2cpg.utils.NodeBuilders
import io.joern.x2cpg.utils.NodeBuilders.*
import io.joern.x2cpg.{Ast, Defines}
import io.shiftleft.codepropertygraph.generated.nodes.*
import io.shiftleft.codepropertygraph.generated.nodes.MethodParameterIn.PropertyDefaults as ParameterDefaults
import io.shiftleft.codepropertygraph.generated.{EdgeTypes, EvaluationStrategies, ModifierTypes}
import io.shiftleft.passes.IntervalKeyPool
import org.slf4j.LoggerFactory
import scala.jdk.CollectionConverters.*
import scala.jdk.OptionConverters.RichOptional
import scala.util.{Failure, Success, Try}
object AstForLambdasCreator {
case class LambdaImplementedInfo(
implementedInterface: Option[ResolvedReferenceType],
implementedMethod: Option[ResolvedMethodDeclaration]
)
case class ClosureBindingEntry(node: ScopeVariable, binding: NewClosureBinding)
case class LambdaBody(body: Ast, capturedVariables: Seq[ClosureBindingEntry]) {
def nodes: Seq[NewNode] = body.nodes.toSeq
}
}
private[expressions] trait AstForLambdasCreator { this: AstCreator =>
private val logger = LoggerFactory.getLogger(this.getClass)
private def createAndPushLambdaMethod(
expr: LambdaExpr,
lambdaMethodName: String,
implementedInfo: LambdaImplementedInfo,
variablesInScope: Seq[ScopeVariable],
expectedLambdaType: ExpectedType
): (NewMethod, LambdaBody) = {
val implementedMethod = implementedInfo.implementedMethod
val implementedInterface = implementedInfo.implementedInterface
// We need to get this information from the expected type as the JavaParser
// symbol solver returns the erased types when resolving the lambda itself.
val expectedTypeParamTypes = genericParamTypeMapForLambda(expectedLambdaType)
val parametersWithoutThis = buildParamListForLambda(expr, implementedMethod, expectedTypeParamTypes)
val returnType = getLambdaReturnType(implementedInterface, implementedMethod, expectedTypeParamTypes)
val lambdaBody = astForLambdaBody(lambdaMethodName, expr.getBody, variablesInScope, returnType)
val thisParam = lambdaBody.nodes
.collect { case identifier: NewIdentifier => identifier }
.find { identifier => identifier.name == NameConstants.This || identifier.name == NameConstants.Super }
.map { _ =>
val typeFullName = scope.enclosingTypeDecl.fullName
Ast(thisNodeForMethod(typeFullName, line(expr)))
}
.toList
val parameters = thisParam ++ parametersWithoutThis
val lambdaParameterNamesToNodes =
parameters
.flatMap(_.root)
.collect { case param: NewMethodParameterIn => param }
.map { param => param.name -> param }
.toMap
val identifiersMatchingParams = lambdaBody.nodes
.collect { case identifier: NewIdentifier => identifier }
.filter { identifier => lambdaParameterNamesToNodes.contains(identifier.name) }
val lambdaMethodNode = createLambdaMethodNode(expr, lambdaMethodName, parametersWithoutThis, returnType)
val returnNode = newMethodReturnNode(returnType.getOrElse(TypeConstants.Any), None, line(expr), column(expr))
val virtualModifier = Some(newModifierNode(ModifierTypes.VIRTUAL))
val staticModifier = Option.when(thisParam.isEmpty)(newModifierNode(ModifierTypes.STATIC))
val privateModifier = Some(newModifierNode(ModifierTypes.PRIVATE))
val lambdaModifier = Some(newModifierNode(ModifierTypes.LAMBDA))
val modifiers = List(virtualModifier, staticModifier, privateModifier, lambdaModifier).flatten.map(Ast(_))
val lambdaMethodAstWithoutRefs =
Ast(lambdaMethodNode)
.withChildren(parameters)
.withChild(lambdaBody.body)
.withChild(Ast(returnNode))
.withChildren(modifiers)
val lambdaMethodAst = identifiersMatchingParams.foldLeft(lambdaMethodAstWithoutRefs)((ast, identifier) =>
ast.withRefEdge(identifier, lambdaParameterNamesToNodes(identifier.name))
)
scope.addLambdaMethod(lambdaMethodAst)
lambdaMethodNode -> lambdaBody
}
private def lambdaMethodSignature(returnType: Option[String], parameters: Seq[Ast]): String = {
val maybeParameterTypes = toOptionList(parameters.map(_.rootType))
val containsEmptyType = maybeParameterTypes.exists(_.contains(ParameterDefaults.TypeFullName))
(returnType, maybeParameterTypes) match {
case (Some(returnTpe), Some(parameterTpes)) if !containsEmptyType =>
composeMethodLikeSignature(returnTpe, parameterTpes)
case _ => composeUnresolvedSignature(parameters.size)
}
}
private def createLambdaMethodNode(
lambdaExpr: LambdaExpr,
lambdaName: String,
parameters: Seq[Ast],
returnType: Option[String]
): NewMethod = {
val enclosingTypeName = scope.enclosingTypeDecl.fullName.getOrElse(Defines.UnresolvedNamespace)
val signature = lambdaMethodSignature(returnType, parameters)
val lambdaFullName = composeMethodFullName(enclosingTypeName, lambdaName, signature)
methodNode(lambdaExpr, lambdaName, "", lambdaFullName, Some(signature), filename)
}
private def createAndPushLambdaTypeDecl(
lambdaMethodNode: NewMethod,
implementedInfo: LambdaImplementedInfo
): NewTypeDecl = {
val inheritsFromTypeFullName =
implementedInfo.implementedInterface
.flatMap(typeInfoCalc.fullName)
.orElse(Some(TypeConstants.Object))
.toList
typeInfoCalc.registerType(lambdaMethodNode.fullName)
val lambdaTypeDeclNode =
NewTypeDecl()
.fullName(lambdaMethodNode.fullName)
.name(lambdaMethodNode.name)
.inheritsFromTypeFullName(inheritsFromTypeFullName)
scope.addLocalDecl(Ast(lambdaTypeDeclNode))
lambdaTypeDeclNode
}
private def getLambdaImplementedInfo(expr: LambdaExpr, expectedType: ExpectedType): LambdaImplementedInfo = {
val maybeImplementedType = {
val maybeResolved = tryWithSafeStackOverflow(expr.calculateResolvedType())
maybeResolved.toOption
.orElse(expectedType.resolvedType)
.collect { case refType: ResolvedReferenceType => refType }
}
val maybeImplementedInterface = maybeImplementedType.flatMap(_.getTypeDeclaration.toScala)
if (maybeImplementedInterface.isEmpty) {
val location = s"$filename:${line(expr)}:${column(expr)}"
logger.debug(
s"Could not resolve the interface implemented by a lambda. Type info may be missing: $location. Type info may be missing."
)
}
val maybeBoundMethod = maybeImplementedInterface.flatMap { interface =>
interface.getDeclaredMethods.asScala
.filter(_.isAbstract)
.filterNot { method =>
// Filter out java.lang.Object methods re-declared by the interface as these are also considered abstract.
// See https://docs.oracle.com/javase/8/docs/api/java/lang/FunctionalInterface.html for details.
Try(method.getSignature) match {
case Success(signature) => ObjectMethodSignatures.contains(signature)
case Failure(_) =>
false // If the signature could not be calculated, it's probably not a standard object method.
}
}
.headOption
}
LambdaImplementedInfo(maybeImplementedType, maybeBoundMethod)
}
private def addClosureBindingsToDiffGraph(
bindingEntries: Iterable[ClosureBindingEntry],
methodRef: NewMethodRef
): Unit = {
bindingEntries.foreach { case ClosureBindingEntry(nodeTypeInfo, closureBinding) =>
diffGraph.addNode(closureBinding)
diffGraph.addEdge(closureBinding, nodeTypeInfo.node, EdgeTypes.REF)
diffGraph.addEdge(methodRef, closureBinding, EdgeTypes.CAPTURE)
}
}
def astForLambdaExpr(expr: LambdaExpr, expectedType: ExpectedType): Ast = {
// TODO: lambda method scope can be static if no non-static captures are used
scope.pushMethodScope(NewMethod(), expectedType, isStatic = false)
val lambdaMethodName = nextClosureName()
val variablesInScope = scope.variablesInScope
val implementedInfo = getLambdaImplementedInfo(expr, expectedType)
val (lambdaMethodNode, lambdaBody) =
createAndPushLambdaMethod(expr, lambdaMethodName, implementedInfo, variablesInScope, expectedType)
val methodRef =
NewMethodRef()
.methodFullName(lambdaMethodNode.fullName)
.typeFullName(lambdaMethodNode.fullName)
.code(lambdaMethodNode.fullName)
addClosureBindingsToDiffGraph(lambdaBody.capturedVariables, methodRef)
val interfaceBinding = implementedInfo.implementedMethod.map { implementedMethod =>
newBindingNode(implementedMethod.getName, lambdaMethodNode.signature, lambdaMethodNode.fullName)
}
val bindingTable = getLambdaBindingTable(
LambdaBindingInfo(lambdaMethodNode.fullName, implementedInfo.implementedInterface, interfaceBinding)
)
val lambdaTypeDeclNode = createAndPushLambdaTypeDecl(lambdaMethodNode, implementedInfo)
BindingTable.createBindingNodes(diffGraph, lambdaTypeDeclNode, bindingTable)
scope.popMethodScope()
Ast(methodRef)
}
private def getLambdaBindingTable(lambdaBindingInfo: LambdaBindingInfo): BindingTable = {
val fullName = lambdaBindingInfo.fullName
bindingTableCache.getOrElseUpdate(
fullName,
createBindingTable(
fullName,
lambdaBindingInfo,
getBindingTable,
new BindingTableAdapterForLambdas(methodSignature)
)
)
}
private def defineCapturedVariables(
lambdaMethodName: String,
capturedVariables: Seq[ScopeVariable]
): Seq[(ClosureBindingEntry, NewLocal)] = {
capturedVariables
.groupBy(_.name)
.map { case (name, variables) =>
val closureBindingId = s"$filename:$lambdaMethodName:$name"
val closureBindingNode = newClosureBindingNode(closureBindingId, name, EvaluationStrategies.BY_SHARING)
val scopeVariable = variables.head
val capturedLocal = newLocalNode(scopeVariable.name, scopeVariable.typeFullName, Option(closureBindingId))
scope.enclosingBlock.foreach(_.addLocal(capturedLocal))
ClosureBindingEntry(scopeVariable, closureBindingNode) -> capturedLocal
}
.toSeq
}
private def astForLambdaBody(
lambdaMethodName: String,
body: Statement,
variablesInScope: Seq[ScopeVariable],
returnType: Option[String]
): LambdaBody = {
val outerScopeVariableNames = variablesInScope.map(x => x.name -> x).toMap
val stmts = body match {
case block: BlockStmt =>
scope.pushBlockScope()
val stmts = block.getStatements.asScala.flatMap(astsForStatement).toSeq
scope.popBlockScope()
stmts
case stmt if returnType.contains(TypeConstants.Void) => astsForStatement(stmt)
case stmt =>
val retNode = returnNode(stmt, s"return ${body.toString}")
val returnArgs = astsForStatement(stmt)
Seq(returnAst(retNode, returnArgs))
}
val capturedVariables =
stmts.flatMap(_.nodes).collect {
case i: NewIdentifier if outerScopeVariableNames.contains(i.name) => outerScopeVariableNames(i.name)
}
val bindingsToLocals = defineCapturedVariables(lambdaMethodName, capturedVariables)
val capturedLocalAsts = bindingsToLocals.map(_._2).map(Ast(_))
val closureBindingEntries = bindingsToLocals.map(_._1)
body match {
case block: BlockStmt =>
val blockAst = Ast(blockNode(block))
.withChildren(capturedLocalAsts)
.withChildren(stmts)
LambdaBody(blockAst, closureBindingEntries)
case stmt =>
val blockAst = Ast(blockNode(stmt))
.withChildren(capturedLocalAsts)
.withChildren(stmts)
LambdaBody(blockAst, closureBindingEntries)
}
}
private def genericParamTypeMapForLambda(expectedType: ExpectedType): ResolvedTypeParametersMap = {
expectedType.resolvedType
// This should always be true for correct code
.collect { case r: ResolvedReferenceType => r }
.map(_.typeParametersMap())
.getOrElse(new ResolvedTypeParametersMap.Builder().build())
}
private def buildParamListForLambda(
expr: LambdaExpr,
maybeBoundMethod: Option[ResolvedMethodDeclaration],
expectedTypeParamTypes: ResolvedTypeParametersMap
): Seq[Ast] = {
val lambdaParameters = expr.getParameters.asScala.toList
val paramTypesList = maybeBoundMethod match {
case Some(resolvedMethod) =>
val resolvedParameters = (0 until resolvedMethod.getNumberOfParams).map(resolvedMethod.getParam)
// Substitute generic typeParam with the expected type if it can be found; leave unchanged otherwise.
resolvedParameters.map(param => Try(param.getType)).map {
case Success(resolvedType: ResolvedTypeVariable) =>
val typ = expectedTypeParamTypes.getValue(resolvedType.asTypeParameter)
typeInfoCalc.fullName(typ)
case Success(resolvedType) => typeInfoCalc.fullName(resolvedType)
case Failure(_) => None
}
case None =>
// Unless types are explicitly specified in the lambda definition,
// this will yield the erased types which is why the actual lambda
// expression parameters are only used as a fallback.
lambdaParameters
.flatMap(param => tryWithSafeStackOverflow(typeInfoCalc.fullName(param.getType)).toOption)
}
if (paramTypesList.sizeIs != lambdaParameters.size) {
logger.error(s"Found different number lambda params and param types for $expr. Some parameters will be missing.")
}
val parameterNodes = lambdaParameters
.zip(paramTypesList)
.zipWithIndex
.map { case ((param, maybeType), idx) =>
val name = param.getNameAsString
val typeFullName = maybeType.getOrElse(TypeConstants.Any)
val code = s"$typeFullName $name"
val evalStrat =
if (tryWithSafeStackOverflow(param.getType).toOption.exists(_.isPrimitiveType)) EvaluationStrategies.BY_VALUE
else EvaluationStrategies.BY_SHARING
val paramNode = NewMethodParameterIn()
.name(name)
.index(idx + 1)
.order(idx + 1)
.code(code)
.evaluationStrategy(evalStrat)
.typeFullName(typeFullName)
.lineNumber(line(expr))
.columnNumber(column(expr))
typeInfoCalc.registerType(typeFullName)
paramNode
}
parameterNodes.foreach { paramNode =>
scope.enclosingMethod.get.addParameter(paramNode)
}
parameterNodes.map(Ast(_))
}
private def getLambdaReturnType(
maybeResolvedLambdaType: Option[ResolvedType],
maybeBoundMethod: Option[ResolvedMethodDeclaration],
expectedTypeParamTypes: ResolvedTypeParametersMap
): Option[String] = {
val maybeBoundMethodReturnType = maybeBoundMethod.flatMap { boundMethod =>
Try(boundMethod.getReturnType).collect {
case returnType: ResolvedTypeVariable => expectedTypeParamTypes.getValue(returnType.asTypeParameter)
case other => other
}.toOption
}
val returnType = maybeBoundMethodReturnType.orElse(maybeResolvedLambdaType)
returnType.flatMap(typeInfoCalc.fullName)
}
}
