From 37cf7316bc49d6e0568f3f5c0153a5113a8d90d7 Mon Sep 17 00:00:00 2001
From: Alexander Udalov <alexander.udalov@jetbrains.com>
Date: Wed, 6 May 2020 13:05:35 +0200
Subject: [PATCH] Do not calculate maxStack size manually when generating
 typeOf

---
 .../codegen/inline/ReifiedTypeInliner.kt      | 13 +++++++++----
 .../jetbrains/kotlin/codegen/inline/typeOf.kt | 19 +++++--------------
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/ReifiedTypeInliner.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/ReifiedTypeInliner.kt
index 10e2f8cb4ee..397f3273493 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/ReifiedTypeInliner.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/ReifiedTypeInliner.kt
@@ -258,13 +258,18 @@ class ReifiedTypeInliner<KT : KotlinTypeMarker>(
         instructions: InsnList,
         type: KT
     ) = rewriteNextTypeInsn(insn, Opcodes.ACONST_NULL) { stubConstNull: AbstractInsnNode ->
-        val newMethodNode = MethodNode(Opcodes.API_VERSION)
-        val stackSize = typeSystem.generateTypeOf(InstructionAdapter(newMethodNode), type, intrinsicsSupport)
+        val newMethodNode = MethodNode(Opcodes.API_VERSION, "fake", "()V", null, null)
+        val mv = wrapWithMaxLocalCalc(newMethodNode)
+        typeSystem.generateTypeOf(InstructionAdapter(mv), type, intrinsicsSupport)
 
-        instructions.insert(insn, newMethodNode.instructions)
+        // Adding a fake return (and removing it below) to trigger maxStack calculation
+        mv.visitInsn(Opcodes.RETURN)
+        mv.visitMaxs(-1, -1)
+
+        instructions.insert(insn, newMethodNode.instructions.apply { remove(last) })
         instructions.remove(stubConstNull)
 
-        maxStackSize = max(maxStackSize, stackSize)
+        maxStackSize = max(maxStackSize, newMethodNode.maxStack)
         return true
     }
 
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/typeOf.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/typeOf.kt
index 47e093f7ca1..7260232e336 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/typeOf.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/inline/typeOf.kt
@@ -36,10 +36,9 @@ private fun TypeSystemCommonBackendContext.putTypeOfReifiedTypeParameter(
     v.aconst(null)
 }
 
-// Returns some upper bound on maximum stack size
 internal fun <KT : KotlinTypeMarker> TypeSystemCommonBackendContext.generateTypeOf(
     v: InstructionAdapter, type: KT, intrinsicsSupport: ReifiedTypeInliner.IntrinsicsSupport<KT>
-): Int {
+) {
     intrinsicsSupport.putClassInstance(v, type)
 
     val argumentsSize = type.argumentsCount()
@@ -50,16 +49,13 @@ internal fun <KT : KotlinTypeMarker> TypeSystemCommonBackendContext.generateType
         v.newarray(K_TYPE_PROJECTION)
     }
 
-    var maxStackSize = 3
-
     for (i in 0 until argumentsSize) {
         if (useArray) {
             v.dup()
             v.iconst(i)
         }
 
-        val stackSize = doGenerateTypeProjection(v, type.getArgument(i), intrinsicsSupport)
-        maxStackSize = maxOf(maxStackSize, stackSize + i + 5)
+        doGenerateTypeProjection(v, type.getArgument(i), intrinsicsSupport)
 
         if (useArray) {
             v.astore(K_TYPE_PROJECTION)
@@ -77,30 +73,27 @@ internal fun <KT : KotlinTypeMarker> TypeSystemCommonBackendContext.generateType
     val signature = Type.getMethodDescriptor(K_TYPE, JAVA_CLASS_TYPE, *projections)
 
     v.invokestatic(REFLECTION, methodName, signature, false)
-
-    return maxStackSize
 }
 
 private fun <KT : KotlinTypeMarker> TypeSystemCommonBackendContext.doGenerateTypeProjection(
     v: InstructionAdapter,
     projection: TypeArgumentMarker,
     intrinsicsSupport: ReifiedTypeInliner.IntrinsicsSupport<KT>
-): Int {
+) {
     // KTypeProjection members could be static, see KT-30083 and KT-30084
     v.getstatic(K_TYPE_PROJECTION.internalName, "Companion", K_TYPE_PROJECTION_COMPANION.descriptor)
 
     if (projection.isStarProjection()) {
         v.invokevirtual(K_TYPE_PROJECTION_COMPANION.internalName, "getSTAR", Type.getMethodDescriptor(K_TYPE_PROJECTION), false)
-        return 1
+        return
     }
 
     @Suppress("UNCHECKED_CAST")
     val type = projection.getType() as KT
     val typeParameterClassifier = type.typeConstructor().getTypeParameterClassifier()
-    val stackSize = if (typeParameterClassifier != null) {
+    if (typeParameterClassifier != null) {
         if (typeParameterClassifier.isReified()) {
             putTypeOfReifiedTypeParameter(v, typeParameterClassifier, type.isMarkedNullable())
-            2
         } else {
             // TODO: support non-reified type parameters in typeOf
             @Suppress("UNCHECKED_CAST")
@@ -116,6 +109,4 @@ private fun <KT : KotlinTypeMarker> TypeSystemCommonBackendContext.doGenerateTyp
         TypeVariance.OUT -> "covariant"
     }
     v.invokevirtual(K_TYPE_PROJECTION_COMPANION.internalName, methodName, Type.getMethodDescriptor(K_TYPE_PROJECTION, K_TYPE), false)
-
-    return stackSize + 1
 }