Add $completion entry to suspend functions' LVT

#KT-28810 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/CoroutineTransformerMethodVisitor.kt

@@ -49,6 +49,8 @@ private const val COROUTINES_METADATA_METHOD_NAME_JVM_NAME = "m"
 private const val COROUTINES_METADATA_CLASS_NAME_JVM_NAME = "c"
 private const val COROUTINES_METADATA_VERSION_JVM_NAME = "v"
 
+const val SUSPEND_FUNCTION_CONTINUATION_PARAMETER = "\$completion"
+
 class CoroutineTransformerMethodVisitor(
     delegate: MethodVisitor,
     access: Int,
@@ -105,6 +107,8 @@ class CoroutineTransformerMethodVisitor(
         if (isForNamedFunction) {
             ReturnUnitMethodTransformer.transform(containingClassInternalName, methodNode)
 
+            addCompletionParameterToLVT(methodNode)
+
             if (allSuspensionPointsAreTailCalls(containingClassInternalName, methodNode, suspensionPoints)) {
                 dropSuspensionMarkers(methodNode, suspensionPoints)
                 return
@@ -197,6 +201,32 @@ class CoroutineTransformerMethodVisitor(
         }
     }
 
+    private fun addCompletionParameterToLVT(methodNode: MethodNode) {
+        val index =
+                /*  all args */ Type.getMethodType(methodNode.desc).argumentTypes.fold(0) { a, b -> a + b.size } +
+                /* this */ (if (isStatic(methodNode.access)) 0 else 1) -
+                /* only last */ 1
+        val startLabel = with(methodNode.instructions) {
+            if (first is LabelNode) first as LabelNode
+            else LabelNode().also { insertBefore(first, it) }
+        }
+
+        val endLabel = with(methodNode.instructions) {
+            if (last is LabelNode) last as LabelNode
+            else LabelNode().also { insert(last, it) }
+        }
+        methodNode.localVariables.add(
+            LocalVariableNode(
+                SUSPEND_FUNCTION_CONTINUATION_PARAMETER,
+                languageVersionSettings.continuationAsmType().descriptor,
+                null,
+                startLabel,
+                endLabel,
+                index
+            )
+        )
+    }
+
     private fun findSuspensionPointLineNumber(suspensionPoint: SuspensionPoint) =
         suspensionPoint.suspensionCallBegin.findPreviousOrNull { it is LineNumberNode } as LineNumberNode?
 
@@ -238,15 +268,11 @@ class CoroutineTransformerMethodVisitor(
     }
 
     private fun fixLvtForParameters(methodNode: MethodNode, startLabel: LabelNode, endLabel: LabelNode) {
-        // We need to skip continuation, since the inliner likes to remap variables there.
-        // But this is not a problem, since we have separate $continuation LVT entry
-
         val paramsNum =
-                /* this */ (if (internalNameForDispatchReceiver != null) 1 else 0) +
-                /* real params */ Type.getArgumentTypes(methodNode.desc).size -
-                /* no continuation */ if (isForNamedFunction) 1 else 0
+                /* this */ (if (isStatic(methodNode.access)) 0 else 1) +
+                /* real params */ Type.getArgumentTypes(methodNode.desc).fold(0) { a, b -> a + b.size }
 
-        for (i in 0..paramsNum) {
+        for (i in 0 until paramsNum) {
             fixRangeOfLvtRecord(methodNode, i, startLabel, endLabel)
         }
     }

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/common/variableLiveness.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.codegen.optimization.common
 
+import org.jetbrains.kotlin.codegen.coroutines.SUSPEND_FUNCTION_CONTINUATION_PARAMETER
 import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
 import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.org.objectweb.asm.Type
@@ -80,7 +81,7 @@ private fun useVar(
     val index = node.instructions.indexOf(insn)
     node.localVariables.filter {
         // Inliner fake variables, despite being present in LVT, are not read, thus are always dead
-        !it.name.startsWith(JvmAbi.LOCAL_VARIABLE_NAME_PREFIX_INLINE_ARGUMENT) && !it.name.startsWith(JvmAbi.LOCAL_VARIABLE_NAME_PREFIX_INLINE_FUNCTION) &&
+        !it.name.isInvisibleDebuggerVariable() &&
                 node.instructions.indexOf(it.start) < index && index < node.instructions.indexOf(it.end) &&
                 Type.getType(it.desc).sort == typeAnnotatedFrame?.getLocal(it.index)?.type?.sort
     }.forEach {
@@ -93,3 +94,8 @@ private fun useVar(
         frame.markAlive(insn.`var`)
     }
 }
+
+private fun String.isInvisibleDebuggerVariable(): Boolean =
+    startsWith(JvmAbi.LOCAL_VARIABLE_NAME_PREFIX_INLINE_ARGUMENT) ||
+            startsWith(JvmAbi.LOCAL_VARIABLE_NAME_PREFIX_INLINE_FUNCTION) ||
+            this == SUSPEND_FUNCTION_CONTINUATION_PARAMETER