remove the "getInitialRange" method for values and instead mark decla…

…rations as operations with effect
Fraunhofer-AISEC · Oct 14, 2024 · f984a2c · f984a2c
1 parent beb4d38
commit f984a2c
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Showing 5 changed files with 34 additions and 35 deletions.
diff --git a/...alysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/AbstractEvaluator.kt b/...alysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/AbstractEvaluator.kt
@@ -60,11 +60,12 @@ class AbstractEvaluator {
         targetName = node.name.toString()
         targetType = getType(node)
         val initializer = getInitializerOf(node, targetType)!!
-        val initialRange = getInitialRange(initializer, targetType)
 
         // evaluate effect of each operation on the list until we reach "node"
         val startState = IntervalState()
-        startState.push(initializer, IntervalLattice(initialRange))
+        startState.push(initializer, IntervalLattice(LatticeInterval.BOTTOM))
+        // TODO: terminates too early since it already knows the state of the first node
+        //  -> mark declarations as node with effect in Integer and start with BOTTOM node!
         val finalState = iterateEOG(initializer, startState, ::handleNode, goalNode)
         // TODO: null-safety
         return finalState!![node]!!.elements
@@ -84,6 +85,8 @@ class AbstractEvaluator {
         state: State<Node, LatticeInterval>,
         worklist: Worklist<Node, Node, LatticeInterval>
     ): State<Node, LatticeInterval> {
+        // TODO: we must not override the current state before they are checked by the worklist!
+        //  otherwise it will seem as if nothing changed
         // If the current node is already done
         // (prevents infinite loop and unnecessary double-checking)
         if (worklist.isDone(currentNode)) {

diff --git a/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Array.kt b/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Array.kt
@@ -27,6 +27,7 @@ package de.fraunhofer.aisec.cpg.analysis.abstracteval.value
 
 import de.fraunhofer.aisec.cpg.analysis.abstracteval.LatticeInterval
 import de.fraunhofer.aisec.cpg.graph.Node
+import de.fraunhofer.aisec.cpg.graph.declarations.VariableDeclaration
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.InitializerListExpression
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.Literal
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.NewArrayExpression
@@ -37,15 +38,13 @@ import org.apache.commons.lang3.NotImplementedException
 class Array<T> : Value {
     override fun applyEffect(current: LatticeInterval, node: Node, name: String): LatticeInterval {
         // There are no functions that change the size of a Java array without destroying it
+        if (node is VariableDeclaration && node.initializer != null) {
+            val initValue = getSize(node.initializer!!)
+            return LatticeInterval.Bounded(initValue, initValue)
+        }
         return current
     }
 
-    override fun getInitialRange(initializer: Node): LatticeInterval {
-        // Consider multi-dimensional arrays (matrices)
-        val size = getSize(initializer)
-        return LatticeInterval.Bounded(size, size)
-    }
-
     private fun getSize(node: Node): Int {
         return when (node) {
             // TODO: could be more performant if you detect that all initializers are Literals

diff --git a/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Integer.kt b/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Integer.kt
@@ -27,14 +27,22 @@ package de.fraunhofer.aisec.cpg.analysis.abstracteval.value
 
 import de.fraunhofer.aisec.cpg.analysis.abstracteval.LatticeInterval
 import de.fraunhofer.aisec.cpg.graph.Node
+import de.fraunhofer.aisec.cpg.graph.declarations.VariableDeclaration
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.AssignExpression
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.Literal
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.UnaryOperator
 import org.apache.commons.lang3.NotImplementedException
 
 class Integer : Value {
     override fun applyEffect(current: LatticeInterval, node: Node, name: String): LatticeInterval {
-        // TODO: recursively evaluate right-hand-side to narrow down results
+        if (node is VariableDeclaration && node.initializer != null) {
+            val initValue =
+                when (val init = node.initializer) {
+                    is Literal<*> -> init.value as? Int ?: throw NotImplementedException()
+                    else -> throw NotImplementedException()
+                }
+            return LatticeInterval.Bounded(initValue, initValue)
+        }
         if (node is UnaryOperator) {
             if (node.input.code == name) {
                 return when (node.operatorCode) {
@@ -83,13 +91,4 @@ class Integer : Value {
         }
         return current
     }
-
-    override fun getInitialRange(initializer: Node): LatticeInterval {
-        val value =
-            when (initializer) {
-                is Literal<*> -> initializer.value as? Int ?: throw NotImplementedException()
-                else -> throw NotImplementedException()
-            }
-        return LatticeInterval.Bounded(value, value)
-    }
 }
diff --git a/...alysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/MutableList.kt b/...alysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/MutableList.kt
@@ -27,6 +27,7 @@ package de.fraunhofer.aisec.cpg.analysis.abstracteval.value
 
 import de.fraunhofer.aisec.cpg.analysis.abstracteval.LatticeInterval
 import de.fraunhofer.aisec.cpg.graph.Node
+import de.fraunhofer.aisec.cpg.graph.declarations.VariableDeclaration
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.MemberCallExpression
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.MemberExpression
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.NewExpression
@@ -35,6 +36,19 @@ import org.apache.commons.lang3.NotImplementedException
 
 class MutableList : Value {
     override fun applyEffect(current: LatticeInterval, node: Node, name: String): LatticeInterval {
+        if (node is VariableDeclaration && node.initializer != null) {
+            when (val init = node.initializer) {
+                is MemberCallExpression -> {
+                    val size = init.arguments.size
+                    return LatticeInterval.Bounded(size, size)
+                }
+                is NewExpression -> {
+                    // TODO: could have a collection as argument!
+                    return LatticeInterval.Bounded(0, 0)
+                }
+                else -> throw NotImplementedException()
+            }
+        }
         // TODO: state can also be estimated by conditions! (if (l.size < 3) ...)
         // TODO: assignment -> new size
         // State can only be directly changed via MemberCalls (add, clear, ...)
@@ -81,18 +95,4 @@ class MutableList : Value {
             else -> current
         }
     }
-
-    override fun getInitialRange(initializer: Node): LatticeInterval {
-        when (initializer) {
-            is MemberCallExpression -> {
-                val size = initializer.arguments.size
-                return LatticeInterval.Bounded(size, size)
-            }
-            is NewExpression -> {
-                // TODO: could have a collection as argument!
-                return LatticeInterval.Bounded(0, 0)
-            }
-            else -> throw NotImplementedException()
-        }
-    }
 }
diff --git a/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Value.kt b/cpg-analysis/src/main/kotlin/de/fraunhofer/aisec/cpg/analysis/abstracteval/value/Value.kt
@@ -38,10 +38,8 @@ interface Value {
         return when (node) {
             null -> null!!
             is Reference -> getInitializer(node.refersTo)
-            is VariableDeclaration -> node.initializer!!
+            is VariableDeclaration -> node
             else -> getInitializer(node.prevDFG.firstOrNull())
         }
     }
-
-    fun getInitialRange(initializer: Node): LatticeInterval
 }