Recalculate max stack on method emitting: optimizations could change it

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

@@ -16,10 +16,12 @@
 
 package org.jetbrains.kotlin.codegen.optimization.common
 
+import org.jetbrains.kotlin.codegen.inline.MaxStackFrameSizeAndLocalsCalculator
 import org.jetbrains.kotlin.codegen.inline.insnText
 import org.jetbrains.kotlin.codegen.optimization.removeNodeGetNext
 import org.jetbrains.kotlin.codegen.pseudoInsns.PseudoInsn
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+import org.jetbrains.org.objectweb.asm.MethodVisitor
 import org.jetbrains.org.objectweb.asm.Opcodes
 import org.jetbrains.org.objectweb.asm.Opcodes.*
 import org.jetbrains.org.objectweb.asm.Type
@@ -71,6 +73,14 @@ fun MethodNode.prepareForEmitting() {
 
         current = prev
     }
+    maxStack = -1
+    accept(MaxStackFrameSizeAndLocalsCalculator(
+            Opcodes.ASM5, access, desc,
+            object : MethodVisitor(Opcodes.ASM5) {
+                override fun visitMaxs(maxStack: Int, maxLocals: Int) {
+                    this@prepareForEmitting.maxStack = maxStack
+                }
+            }))
 }
 
 fun MethodNode.stripOptimizationMarkers() {

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt

@@ -46,14 +46,13 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
         private var changes = false
 
         fun run(): Boolean {
-            val stackOnThrowExceptions = hashMapOf<AbstractInsnNode, Int>()
+            val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode()
-            val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode(stackOnThrowExceptions)
+            eliminateRedundantChecks(checkedReferenceTypes)
-            eliminateRedundantChecks(checkedReferenceTypes, stackOnThrowExceptions)
 
             return changes
         }
 
-        private fun analyzeTypesAndRemoveDeadCode(stackOnThrowExceptionsHolder: MutableMap<AbstractInsnNode, Int>): Map<AbstractInsnNode, Type> {
+        private fun analyzeTypesAndRemoveDeadCode(): Map<AbstractInsnNode, Type> {
             val insns = methodNode.instructions.toArray()
             val frames = analyze(internalClassName, methodNode, OptimizationBasicInterpreter())
 
@@ -67,8 +66,6 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
                     insn.isCheckParameterIsNotNull() ||
                     insn.isCheckExpressionValueIsNotNull() ->
                         relevantReferenceTypes[insn] = frame.peek(1)?.type ?: continue@insnLoop
-                    insn.isThrowIntrinsicWithoutArguments() ->
-                        stackOnThrowExceptionsHolder[insn] = frame.maxStackSize
                     insn.isPseudo(PseudoInsn.STORE_NOT_NULL) -> {
                         val previous = insn.previous ?: continue@insnLoop
                         if (previous.opcode != Opcodes.ASTORE) continue@insnLoop
@@ -87,10 +84,9 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
         }
 
         private fun eliminateRedundantChecks(
-                checkedReferenceTypes: Map<AbstractInsnNode, Type>,
+                checkedReferenceTypes: Map<AbstractInsnNode, Type>
-                stackOnThrowExceptions: MutableMap<AbstractInsnNode, Int>
         ) {
-            val nullabilityAssumptions = injectNullabilityAssumptions(checkedReferenceTypes, stackOnThrowExceptions)
+            val nullabilityAssumptions = injectNullabilityAssumptions(checkedReferenceTypes)
 
             val nullabilityMap = analyzeNullabilities()
 
@@ -100,9 +96,8 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
         }
 
         private fun injectNullabilityAssumptions(
-                checkedReferenceTypes: Map<AbstractInsnNode, Type>,
+                checkedReferenceTypes: Map<AbstractInsnNode, Type>
-                stackOnThrowExceptions: MutableMap<AbstractInsnNode, Int>
+        ) = NullabilityAssumptionsBuilder(checkedReferenceTypes).injectNullabilityAssumptions()
-        ) = NullabilityAssumptionsBuilder(checkedReferenceTypes, stackOnThrowExceptions).injectNullabilityAssumptions()
 
         private fun analyzeNullabilities(): Map<AbstractInsnNode, StrictBasicValue> {
             val frames = analyze(internalClassName, methodNode, NullabilityInterpreter())
@@ -186,8 +181,7 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
         }
 
         private inner class NullabilityAssumptionsBuilder(
-                val relatedReferenceTypes: Map<AbstractInsnNode, Type>,
+                val relatedReferenceTypes: Map<AbstractInsnNode, Type>
-                val stackOnThrowExceptions: MutableMap<AbstractInsnNode, Int>
         ) {
 
             private val checksDependingOnVariable = HashMap<Int, MutableList<AbstractInsnNode>>()
@@ -387,7 +381,7 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
                     })
                 }
 
-                methodNode.maxStack = Math.max(methodNode.maxStack, (stackOnThrowExceptions[insn] ?: -1) + 1)
+                methodNode.maxStack = methodNode.maxStack + 1 //will be recalculated in prepareForEmitting
             }
 
             private fun NullabilityAssumptions.injectCodeForStoreNotNull(insn: AbstractInsnNode, varType: Type) {

compiler/testData/codegen/bytecodeText/maxStackAfterOptimizations.kt

@@ -0,0 +1,5 @@
+fun test() {
+    1
+}
+
+// 1 MAXSTACK = 0

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -300,6 +300,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
         doTest(fileName);
     }
 
+    @TestMetadata("maxStackAfterOptimizations.kt")
+    public void testMaxStackAfterOptimizations() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/maxStackAfterOptimizations.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("noFlagAnnotations.kt")
     public void testNoFlagAnnotations() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/noFlagAnnotations.kt");