Don't instrument args reads at code line 0 (722). (#724)

It is code inserted by compiler to check notnull-ness and other invariants.

Author: lev-serebryakov-jetbrains

src/jvm/main/org/jetbrains/kotlinx/lincheck/transformation/LincheckClassVisitor.kt

@@ -83,6 +83,8 @@ internal class LincheckClassVisitor(
         fun MethodVisitor.newAdapter() = GeneratorAdapter(this, access, methodName, desc)
         fun MethodVisitor.newNonRemappingAdapter() = GeneratorAdapterWithoutLocals(this, access, methodName, desc)
 
+        val isStatic = access and ACC_STATIC != 0
+
         if (instrumentationMode == STRESS) {
             return if (methodName != "<clinit>" && methodName != "<init>") {
                 CoroutineCancellabilitySupportTransformer(mv, access, className, methodName, desc)
@@ -118,7 +120,7 @@ internal class LincheckClassVisitor(
                 analyzerAdapter
             }
             val locals: Map<Int, List<LocalVariableInfo>> = methods[methodName + desc]?.variables ?: emptyMap()
-            mv = LocalVariablesAccessTransformer(fileName, className, methodName, mv.newAdapter(), locals)
+            mv = LocalVariablesAccessTransformer(fileName, className, methodName, mv.newAdapter(), desc, isStatic, locals)
 
             // Inline method call transformer relies on the original variables' indices, so it should go before (in FIFO order)
             // all transformers which can create local variables.
@@ -263,7 +265,7 @@ internal class LincheckClassVisitor(
             aa
         }
         val locals: Map<Int, List<LocalVariableInfo>> = methods[methodName + desc]?.variables ?: emptyMap()
-        mv = LocalVariablesAccessTransformer(fileName, className, methodName, mv.newAdapter(), locals)
+        mv = LocalVariablesAccessTransformer(fileName, className, methodName, mv.newAdapter(), desc, isStatic, locals)
         // Inline method call transformer relies on the original variables' indices, so it should go before (in FIFO order)
         // all transformers which can create local variables.
         // We cannot use trick with
@@ -308,6 +310,8 @@ internal open class ManagedStrategyMethodVisitor(
         adapter.push(codeLocationId)
     }
 
+    protected fun isKnownLineNumber(): Boolean = lineNumber > 0
+
     override fun visitLineNumber(line: Int, start: Label) {
         lineNumber = line
         super.visitLineNumber(line, start)

src/jvm/main/org/jetbrains/kotlinx/lincheck/transformation/transformers/LocalVariablesAccessTransformer.kt

@@ -10,6 +10,7 @@
 
 package org.jetbrains.kotlinx.lincheck.transformation.transformers
 
+import org.jetbrains.kotlinx.lincheck.tracedata.Types.convertAsmMethodType
 import org.jetbrains.kotlinx.lincheck.tracedata.VariableDescriptor
 import org.jetbrains.kotlinx.lincheck.tracedata.variableCache
 import org.jetbrains.kotlinx.lincheck.transformation.*
@@ -23,10 +24,13 @@ internal class LocalVariablesAccessTransformer(
     className: String,
     methodName: String,
     adapter: GeneratorAdapter,
+    desc: String,
+    isStatic: Boolean,
     private val locals: Map<Int, List<LocalVariableInfo>>,
 ) : ManagedStrategyMethodVisitor(fileName, className, methodName, adapter) {
     private var turnoffTransform = false
     private val visitedLabels = HashSet<Label>()
+    private val numberOfLocals = convertAsmMethodType(desc).argumentTypes.size  + if (isStatic) 0 else 1
 
     override fun visitLabel(label: Label) = adapter.run {
         visitedLabels += label
@@ -94,6 +98,12 @@ internal class LocalVariablesAccessTransformer(
     }
 
     private fun visitReadVarInsn(localVariableInfo: LocalVariableInfo, opcode: Int, varIndex: Int) = adapter.run {
+        // Skip variable read if it is in an unknown line of code and variable is argument
+        // It can be code inserted by compiler to check Null invariant
+        if (!isKnownLineNumber() && varIndex < numberOfLocals) {
+            visitVarInsn(opcode, varIndex)
+            return
+        }
         invokeIfInAnalyzedCode(
             original = {
                 visitVarInsn(opcode, varIndex)