Fix parent static field instrumentation

usvm-jvm-instrumentation/src/main/kotlin/org/usvm/instrumentation/instrumentation/JcInstructionTracer.kt

@@ -121,17 +121,24 @@ object JcInstructionTracer : Tracer<Trace> {
         accessType: StaticFieldAccessType,
         jcClasspath: JcClasspath
     ): Long {
-        val jcClass =
+        var jcClass =
             jcRawFieldRef.declaringClass.toJcClassOrInterface(jcClasspath) ?: error("Can't find class in classpath")
-        val encodedClass = encodedClasses.getOrPut(jcClass) { EncodedClass(currentClassIndex++) }
-        val indexedJcField =
-            jcClass.declaredFields.withIndex()
-                .find { it.value.isStatic && it.value.name == jcRawFieldRef.fieldName }
-                ?: error("Field not found")
-        val accessTypeId = accessType.ordinal.toLong()
-        val instId = encodeStaticFieldAccessId(encodedClass.id, indexedJcField.index.toLong(), accessTypeId)
-        encodedJcStaticFieldRef[instId] = indexedJcField.value to accessType
-        return instId
+        while (true) {
+            val encodedClass = encodedClasses.getOrPut(jcClass) { EncodedClass(currentClassIndex++) }
+            val indexedJcField =
+                jcClass.declaredFields.withIndex()
+                    .find { it.value.isStatic && it.value.name == jcRawFieldRef.fieldName }
+            if (indexedJcField == null) {
+                // static fields can be accessed via subclass of declaring class
+                jcClass = jcClass.superClass
+                    ?: error("Field `${jcRawFieldRef.declaringClass.typeName}.${jcRawFieldRef.fieldName}` not found")
+                continue
+            }
+            val accessTypeId = accessType.ordinal.toLong()
+            val instId = encodeStaticFieldAccessId(encodedClass.id, indexedJcField.index.toLong(), accessTypeId)
+            encodedJcStaticFieldRef[instId] = indexedJcField.value to accessType
+            return instId
+        }
     }
 
     private fun decode(jcInstructionId: Long): JcInst =

usvm-jvm-instrumentation/src/samples/java/example/ClassWithStaticField.java

@@ -0,0 +1,5 @@
+package example;
+
+public class ClassWithStaticField {
+    public static String STATIC_FIELD = "static field content";
+}

usvm-jvm-instrumentation/src/samples/java/example/ParentStaticFieldUser.java

@@ -0,0 +1,7 @@
+package example;
+
+public class ParentStaticFieldUser extends ClassWithStaticField {
+    public static String getParentStaticField() {
+        return ParentStaticFieldUser.STATIC_FIELD;
+    }
+}

usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/executor/ConcreteExecutorTests.kt

@@ -9,6 +9,7 @@ import org.usvm.instrumentation.testcase.api.UTestExecutionExceptionResult
 import org.usvm.instrumentation.testcase.api.UTestExecutionSuccessResult
 import org.usvm.instrumentation.testcase.descriptor.UTestConstantDescriptor
 import org.usvm.instrumentation.util.UTestCreator
+import kotlin.test.assertContains
 import kotlin.test.assertEquals
 import kotlin.test.assertIs
 import kotlin.test.assertNotNull
@@ -248,4 +249,16 @@ class ConcreteExecutorTests: UTestConcreteExecutorTest() {
         assertIs<UTestExecutionSuccessResult>(res)
     }
 
+    @Test
+    fun `get parent static field`() = executeTest {
+        val uTest = UTestCreator.ParentStaticFieldUser.getParentStaticField(jcClasspath)
+        val res = uTestConcreteExecutor.executeAsync(uTest)
+        assertIs<UTestExecutionSuccessResult>(res)
+        val result = res.result
+        assertNotNull(result)
+        assertIs<UTestConstantDescriptor.String>(result)
+        assertEquals("static field content", result.value)
+        assertContains(res.resultState.statics.keys.map { it.name }, "STATIC_FIELD")
+    }
+
 }

usvm-jvm-instrumentation/src/test/kotlin/org/usvm/instrumentation/util/UTestCreator.kt

@@ -498,4 +498,13 @@ object UTestCreator {
             return UTest(listOf(), methodCall)
         }
     }
+
+    object ParentStaticFieldUser {
+        fun getParentStaticField(jcClasspath: JcClasspath): UTest {
+            val jcClass = jcClasspath.findClass("example.ParentStaticFieldUser")
+            val jcMethod = jcClass.declaredMethods.find { it.name == "getParentStaticField" }!!
+
+            return UTest(listOf(), UTestStaticMethodCall(jcMethod, emptyList()))
+        }
+    }
 }