First working version of function Summaries

Fraunhofer-AISEC · Dec 10, 2024 · c521a21 · c521a21
1 parent 1948ca3
commit c521a21
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Showing 2 changed files with 51 additions and 3 deletions.
diff --git a/cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/PointsToPass.kt b/cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/PointsToPass.kt
@@ -244,7 +244,7 @@ class PointsToPass(ctx: TranslationContext) : EOGStarterPass(ctx, orderDependenc
             // doubleState.
 
             // First, collect all writes to all parameters
-            var changedParams = mutableMapOf<Node, MutableSet<Pair<Node, Boolean>>>()
+            val changedParams = mutableMapOf<Node, MutableSet<Pair<Node, Boolean>>>()
             currentNode.invokes.forEach { fd ->
                 val tmp = ctx.config.functionSummaries.getLastWrites(fd)
                 for ((k, v) in tmp) {
@@ -281,7 +281,26 @@ class PointsToPass(ctx: TranslationContext) : EOGStarterPass(ctx, orderDependenc
                                 } else {
                                     sources.add(currentNode.arguments[value.argumentIndex])
                                 }
-                        //                            else -> null
+                            is ParameterMemoryValue -> {
+                                // In case the FunctionSummary says that we have to use the
+                                // dereferenced value here, we look up the argument, dereference it,
+                                // and then add it to the sources
+                                if (value.name.localName == "derefvalue") {
+                                    val p =
+                                        currentNode.invokes
+                                            .flatMap { it.parameters }
+                                            .filter { it.name == value.name.parent }
+                                    p.forEach {
+                                        val arg = currentNode.arguments[it.argumentIndex]
+                                        sources.addAll(
+                                            doubleState.getValues(arg).flatMap {
+                                                doubleState.getValues(it)
+                                            }
+                                        )
+                                    }
+                                }
+                            }
+                            else -> sources.add(value)
                         }
                     }
                     if (destinations != null && sources.isNotEmpty()) {

diff --git a/cpg-language-cxx/src/test/kotlin/de/fraunhofer/aisec/cpg/passes/PointsToPassTest.kt b/cpg-language-cxx/src/test/kotlin/de/fraunhofer/aisec/cpg/passes/PointsToPassTest.kt
@@ -1112,6 +1112,20 @@ class PointsToPassTest {
                 .firstOrNull()
         assertNotNull(iRefLine234)
 
+        val iRefLine237 =
+            tu.allChildren<Reference> {
+                    it.location?.region?.startLine == 237 && it.name.localName == "i"
+                }
+                .firstOrNull()
+        assertNotNull(iRefLine237)
+
+        val iRefLine240 =
+            tu.allChildren<Reference> {
+                    it.location?.region?.startLine == 240 && it.name.localName == "i"
+                }
+                .firstOrNull()
+        assertNotNull(iRefLine240)
+
         // Dereferences
         val pDerefLine231 =
             tu.allChildren<PointerDereference> {
@@ -1134,6 +1148,13 @@ class PointsToPassTest {
                 .firstOrNull()
         assertNotNull(pDerefLine237)
 
+        val pDerefLine240 =
+            tu.allChildren<PointerDereference> {
+                    it.location?.region?.startLine == 240 && it.name.localName == "p"
+                }
+                .firstOrNull()
+        assertNotNull(pDerefLine240)
+
         // BinaryOperators
         val binOpLine207 =
             tu.allChildren<BinaryOperator> { it.location?.region?.startLine == 207 }.firstOrNull()
@@ -1162,8 +1183,16 @@ class PointsToPassTest {
 
         // Line 237
         assertEquals(1, pDerefLine237.memoryAddress.size)
-        assertEquals(jDecl.memoryAddress, pDerefLine237.memoryAddress.firstOrNull())
+        assertEquals(iDecl.memoryAddress, pDerefLine237.memoryAddress.firstOrNull())
         assertEquals(1, pDerefLine237.prevDFG.size)
         assertEquals(jDecl.prevDFG.firstOrNull(), pDerefLine237.prevDFG.firstOrNull())
+
+        // Line 240
+        assertEquals(1, pDerefLine240.memoryAddress.size)
+        assertEquals(iDecl.memoryAddress, pDerefLine240.memoryAddress.firstOrNull())
+        assertEquals(1, pDerefLine240.prevDFG.size)
+        assertEquals(binOpLine212, pDerefLine240.prevDFG.firstOrNull())
+        assertEquals(1, iRefLine240.prevDFG.size)
+        assertEquals(binOpLine212, iRefLine240.prevDFG.firstOrNull())
     }
 }