[Commonizer] Stats collector: support aggregated stats

2020-06-15 11:44:22 +07:00
parent f7ceacb15c
commit 205510863a
13 changed files with 438 additions and 202 deletions
@@ -5,6 +5,8 @@

 package org.jetbrains.kotlin.descriptors.commonizer

+import org.jetbrains.kotlin.descriptors.commonizer.stats.StatsCollector
+
 class Parameters(
    val statsCollector: StatsCollector? = null
 ) {
@@ -7,11 +7,11 @@ package org.jetbrains.kotlin.descriptors.commonizer.builder

 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.StatsCollector
 import org.jetbrains.kotlin.descriptors.commonizer.Target
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.CirRootNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.dimension
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.stats.StatsCollector
 import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.utils.createKotlinNativeForwardDeclarationsModule
@@ -10,18 +10,20 @@ internal class BooleanOptionType(
    description: String,
    mandatory: Boolean
 ) : OptionType<Boolean>(alias, description, mandatory) {
-    private val trueTokens = setOf("1", "on", "yes", "true")
-    private val falseTokens = setOf("0", "off", "no", "false")
-
    override fun parse(rawValue: String, onError: (reason: String) -> Nothing): Option<Boolean> {
        val value = rawValue.toLowerCase().let {
            when (it) {
-                in trueTokens -> true
-                in falseTokens -> false
+                in TRUE_TOKENS -> true
+                in FALSE_TOKENS -> false
                else -> onError("Invalid boolean value: $it")
            }
        }

        return Option(this, value)
    }
+
+    companion object {
+        private val TRUE_TOKENS = setOf("1", "on", "yes", "true")
+        private val FALSE_TOKENS = setOf("0", "off", "no", "false")
+    }
 }
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.cli
+
+import org.jetbrains.kotlin.descriptors.commonizer.konan.NativeDistributionCommonizer.StatsType
+
+internal object StatsTypeOptionType : OptionType<StatsType>("log-stats", DESCRIPTION, mandatory = false) {
+    override fun parse(rawValue: String, onError: (reason: String) -> Nothing): Option<StatsType> {
+        val value = StatsType.values().firstOrNull { it.name.equals(rawValue, ignoreCase = true) }
+            ?: onError("Invalid stats type: $rawValue")
+        return Option(this, value)
+    }
+}
+
+private val DESCRIPTION = buildString {
+    StatsType.values().joinTo(this) {
+        val item = "\"${it.name.toLowerCase()}\""
+        if (it == StatsType.NONE) "$item (default)" else item
+    }
+    append(";\nlog commonization stats")
+}
@@ -28,7 +28,7 @@ internal enum class TaskType(
                "Boolean (default false);\nwhether to copy Kotlin/Native endorsed libraries to the destination",
                mandatory = false
            ),
-            BooleanOptionType("log-stats", "Boolean (default false); Log commonization stats", mandatory = false)
+            StatsTypeOptionType
        ),
        ::NativeDistributionCommonize
    ),
@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.descriptors.commonizer.cli

 import org.jetbrains.kotlin.descriptors.commonizer.konan.NativeDistributionCommonizer
+import org.jetbrains.kotlin.descriptors.commonizer.konan.NativeDistributionCommonizer.StatsType
 import org.jetbrains.kotlin.konan.library.KONAN_DISTRIBUTION_KLIB_DIR
 import org.jetbrains.kotlin.konan.library.KONAN_DISTRIBUTION_PLATFORM_LIBS_DIR
 import org.jetbrains.kotlin.konan.target.KonanTarget
@@ -44,7 +45,7 @@ internal class NativeDistributionCommonize(options: Collection<Option<*>>) : Tas

        val copyStdlib = getOptional<Boolean, BooleanOptionType> { it == "copy-stdlib" } ?: false
        val copyEndorsedLibs = getOptional<Boolean, BooleanOptionType> { it == "copy-endorsed-libs" } ?: false
-        val withStats = getOptional<Boolean, BooleanOptionType> { it == "log-stats" } ?: false
+        val statsType = getOptional<StatsType, StatsTypeOptionType> { it == "log-stats" } ?: StatsType.NONE

        val descriptionSuffix = estimateLibrariesCount(distribution, targets)?.let { " ($it items)" } ?: ""
        val description = "${logPrefix}Preparing commonized Kotlin/Native libraries for targets $targets$descriptionSuffix"
@@ -57,7 +58,7 @@ internal class NativeDistributionCommonize(options: Collection<Option<*>>) : Tas
            destination = destination,
            copyStdlib = copyStdlib,
            copyEndorsedLibs = copyEndorsedLibs,
-            withStats = withStats,
+            statsType = statsType,
            logger = CliLoggerAdapter(2)
        ).run()

@@ -13,6 +13,10 @@ import org.jetbrains.kotlin.config.LanguageVersionSettingsImpl
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.descriptors.commonizer.*
 import org.jetbrains.kotlin.descriptors.commonizer.Target
+import org.jetbrains.kotlin.descriptors.commonizer.konan.NativeDistributionCommonizer.StatsType.*
+import org.jetbrains.kotlin.descriptors.commonizer.stats.AggregatedStatsCollector
+import org.jetbrains.kotlin.descriptors.commonizer.stats.FileStatsOutput
+import org.jetbrains.kotlin.descriptors.commonizer.stats.RawStatsCollector
 import org.jetbrains.kotlin.descriptors.commonizer.utils.ResettableClockMark
 import org.jetbrains.kotlin.descriptors.konan.NATIVE_STDLIB_MODULE_NAME
 import org.jetbrains.kotlin.konan.library.*
@@ -37,9 +41,13 @@ class NativeDistributionCommonizer(
    private val destination: File,
    private val copyStdlib: Boolean,
    private val copyEndorsedLibs: Boolean,
-    private val withStats: Boolean,
+    private val statsType: StatsType,
    private val logger: Logger
 ) {
+    enum class StatsType {
+        RAW, AGGREGATED, NONE
+    }
+
    fun run() {
        checkPreconditions()

@@ -123,7 +131,11 @@ class NativeDistributionCommonizer(
    }

    private fun commonize(librariesByTargets: Map<InputTarget, NativeDistributionLibraries>): Result {
-        val statsCollector = if (withStats) NativeStatsCollector(targets, destination) else null
+        val statsCollector = when (statsType) {
+            RAW -> RawStatsCollector(targets, FileStatsOutput(destination, "raw"))
+            AGGREGATED -> AggregatedStatsCollector(targets, FileStatsOutput(destination, "aggregated"))
+            NONE -> null
+        }
        statsCollector.use {
            val parameters = Parameters(statsCollector).apply {
                librariesByTargets.forEach { (target, libraries) ->
@@ -1,188 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.descriptors.commonizer.konan
-
-import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.ClassKind.ENUM_CLASS
-import org.jetbrains.kotlin.descriptors.ClassKind.ENUM_ENTRY
-import org.jetbrains.kotlin.descriptors.commonizer.StatsCollector
-import org.jetbrains.kotlin.descriptors.commonizer.utils.firstNonNull
-import org.jetbrains.kotlin.descriptors.commonizer.utils.fqNameWithTypeParameters
-import org.jetbrains.kotlin.konan.target.KonanTarget
-import org.jetbrains.kotlin.resolve.DescriptorUtils
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
-import java.io.File
-
-/**
- * Allows printing commonization statistics to the file system.
- *
- * File format: text, "|"-separated columns.
- *
- * Header row: "FQ Name|Extension Receiver|Parameter Names|Parameter Types|Declaration Type|common|<platform1>|<platform2>[|<platformN>...]"
- *
- * Possible values for "Declaration Type":
- * - MODULE
- * - CLASS
- * - INTERFACE
- * - OBJECT
- * - COMPANION_OBJECT
- * - ENUM_CLASS
- * - ENUM_ENTRY
- * - TYPE_ALIAS
- * - CLASS_CONSTRUCTOR
- * - FUN
- * - VAL
- *
- * Possible values for "common" column:
- * - L = declaration lifted up to common fragment
- * - E = successfully commonized, expect declaration generated
- * - "-" = no common declaration
- *
- * Possible values for each target platform column:
- * - A = successfully commonized, actual declaration generated
- * - O = not commonized, the declaration is as in the original library
- * - "-" = no such declaration in the original library (or declaration has been lifted up)
- *
- * Example of output:
-
-FQ Name|Extension Receiver|Parameter Names|Parameter Types|Declaration Type|common|macos_x64|ios_x64
-<SystemConfiguration>||||MODULE|E|A|A
-platform.SystemConfiguration.SCPreferencesContext||||CLASS|E|A|A
-platform.SystemConfiguration.SCPreferencesContext.Companion||||COMPANION_OBJECT|E|A|A
-platform.SystemConfiguration.SCNetworkConnectionContext||||CLASS|E|A|A
-platform.SystemConfiguration.SCNetworkConnectionContext.Companion||||COMPANION_OBJECT|E|A|A
-platform.SystemConfiguration.SCDynamicStoreRefVar||||TYPE_ALIAS|-|O|O
-platform.SystemConfiguration.SCVLANInterfaceRef||||TYPE_ALIAS|-|O|O
-
- */
-class NativeStatsCollector(
-    private val targets: List<KonanTarget>,
-    destination: File
-) : StatsCollector {
-
-    init {
-        destination.mkdirs()
-    }
-
-    private val writer = destination.resolve("plain_stats.csv").printWriter()
-    private var headerWritten = false
-
-    override fun logStats(output: List<DeclarationDescriptor?>) {
-        if (!headerWritten) {
-            headerWritten = true
-            writeHeader()
-        }
-
-        val firstNotNull = output.firstNonNull()
-        val lastIsNull = output.last() == null
-
-        val row = buildString {
-            appendName(firstNotNull)
-            append(SEPARATOR)
-            append(firstNotNull.declarationType) // readable declaration type
-            append(SEPARATOR)
-
-            var isLiftedUp = !lastIsNull
-            val platformItems = StringBuilder().apply {
-                for (index in 0 until output.size - 1) {
-                    append(SEPARATOR)
-                    append(
-                        when {
-                            output[index] == null -> '-' // absent
-                            lastIsNull -> 'O' // original (not commonized)
-                            else -> {
-                                isLiftedUp = false
-                                'A' // actual (commonized)
-                            }
-                        }
-                    )
-                }
-            }
-
-            append(
-                when {
-                    isLiftedUp -> 'L'
-                    lastIsNull -> '-'
-                    else -> 'E'
-                }
-            ) // common
-
-            append(platformItems)
-        }
-
-        writer.println(row)
-    }
-
-    override fun close() = writer.close()
-
-    private fun writeHeader() {
-        val row = buildString {
-            append("FQ Name")
-            append(SEPARATOR)
-            append("Extension Receiver")
-            append(SEPARATOR)
-            append("Parameter Names")
-            append(SEPARATOR)
-            append("Parameter Types")
-            append(SEPARATOR)
-            append("Declaration Type")
-            append(SEPARATOR)
-            append("common")
-
-            targets.forEach { target ->
-                append(SEPARATOR)
-                append(target.name)
-            }
-        }
-
-        writer.println(row)
-    }
-
-    companion object {
-        private const val SEPARATOR = '|'
-
-        @Suppress("NOTHING_TO_INLINE")
-        private inline fun StringBuilder.appendName(descriptor: DeclarationDescriptor) {
-            // name
-            append(if (descriptor is ModuleDescriptor) descriptor.name.asString() else descriptor.fqNameSafe.asString())
-            append(SEPARATOR)
-
-            // extension receiver
-            if (descriptor is PropertyDescriptor || descriptor is SimpleFunctionDescriptor) {
-                append((descriptor as CallableDescriptor).extensionReceiverParameter?.type?.fqNameWithTypeParameters.orEmpty())
-            }
-            append(SEPARATOR)
-
-            if (descriptor is ConstructorDescriptor || descriptor is SimpleFunctionDescriptor) {
-                // parameter names
-                (descriptor as FunctionDescriptor).valueParameters.joinTo(this) { it.name.asString() }
-                append(SEPARATOR)
-                // parameter types
-                descriptor.valueParameters.joinTo(this) { it.type.fqNameWithTypeParameters }
-            } else {
-                append(SEPARATOR)
-            }
-        }
-
-        private inline val DeclarationDescriptor.topLevelnessPrefix: String
-            get() = if (DescriptorUtils.isTopLevelDeclaration(this)) "TOP-LEVEL " else "NESTED "
-
-        private inline val DeclarationDescriptor.declarationType: String
-            get() = when (this) {
-                is ClassDescriptor -> when {
-                    isCompanionObject -> "COMPANION_OBJECT"
-                    kind == ENUM_CLASS || kind == ENUM_ENTRY -> kind.toString()
-                    else -> topLevelnessPrefix + kind.toString()
-                }
-                is TypeAliasDescriptor -> "TYPE_ALIAS"
-                is ClassConstructorDescriptor -> "CLASS_CONSTRUCTOR"
-                is FunctionDescriptor -> topLevelnessPrefix + "FUN"
-                is PropertyDescriptor -> topLevelnessPrefix + if (isConst) "CONST-VAL" else "VAL"
-                is ModuleDescriptor -> "MODULE"
-                else -> "UNKNOWN: ${this::class.java}"
-            }
-    }
-}
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.stats
+
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.commonizer.stats.AggregatedStatsCollector.AggregatedStatsRow
+import org.jetbrains.kotlin.descriptors.commonizer.stats.RawStatsCollector.CommonDeclarationStatus.*
+import org.jetbrains.kotlin.konan.target.KonanTarget
+
+class AggregatedStatsCollector(
+    targets: List<KonanTarget>,
+    private val output: StatsOutput
+) : StatsCollector {
+    private val aggregatingOutput = AggregatingOutput()
+    private val wrappedCollector = RawStatsCollector(targets, aggregatingOutput)
+
+    override fun logStats(result: List<DeclarationDescriptor?>) {
+        wrappedCollector.logStats(result)
+    }
+
+    override fun close() {
+        output.writeHeader(AggregatedStatsHeader)
+
+        aggregatingOutput.aggregatedStats.keys.sortedBy { it }.forEach { key ->
+            val row = aggregatingOutput.aggregatedStats.getValue(key)
+            output.writeRow(row)
+        }
+
+        output.close()
+        wrappedCollector.close()
+    }
+
+    object AggregatedStatsHeader : StatsOutput.StatsHeader {
+        private val headerItems = listOf(
+            "Declaration Type",
+            "Lifted Up",
+            "Lifted Up, %%",
+            "Commonized",
+            "Commonized, %%",
+            "Missed in s. targets",
+            "Missed in s. targets, %%",
+            "Failed: Other",
+            "Failed: Other, %%",
+            "Total"
+        )
+
+        override fun toList(): List<String> = headerItems
+    }
+
+    class AggregatedStatsRow(
+        private val declarationType: DeclarationType
+    ) : StatsOutput.StatsRow {
+        var liftedUp: Int = 0
+        var successfullyCommonized: Int = 0
+        var failedBecauseAbsent: Int = 0
+        var failedOther: Int = 0
+
+        override fun toList(): List<String> {
+            val total = liftedUp + successfullyCommonized + failedBecauseAbsent + failedOther
+
+            fun fraction(amount: Int): Double = if (total > 0) amount.toDouble() / total else 0.0
+
+            return listOf(
+                declarationType.alias,
+                liftedUp.toString(),
+                fraction(liftedUp).toString(),
+                successfullyCommonized.toString(),
+                fraction(successfullyCommonized).toString(),
+                failedBecauseAbsent.toString(),
+                fraction(failedBecauseAbsent).toString(),
+                failedOther.toString(),
+                fraction(failedOther).toString(),
+                total.toString()
+            )
+        }
+    }
+
+}
+
+@Suppress("MoveVariableDeclarationIntoWhen")
+private class AggregatingOutput : StatsOutput {
+    val aggregatedStats = HashMap<DeclarationType, AggregatedStatsRow>()
+
+    override fun writeHeader(header: StatsOutput.StatsHeader) {
+        check(header is RawStatsCollector.RawStatsHeader)
+        // do nothing
+    }
+
+    override fun writeRow(row: StatsOutput.StatsRow) {
+        check(row is RawStatsCollector.RawStatsRow)
+
+        val aggregatedStatsRow = aggregatedStats.computeIfAbsent(row.declarationType, ::AggregatedStatsRow)
+        when (row.common) {
+            LIFTED_UP -> aggregatedStatsRow.liftedUp++
+            EXPECT -> aggregatedStatsRow.successfullyCommonized++
+            ABSENT -> {
+                if (row.platform.any { it == RawStatsCollector.PlatformDeclarationStatus.ABSENT }) {
+                    aggregatedStatsRow.failedBecauseAbsent++
+                } else {
+                    aggregatedStatsRow.failedOther++
+                }
+            }
+        }
+    }
+
+    override fun close() = Unit
+}
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.stats
+
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+
+enum class DeclarationType(val alias: String) {
+    TOP_LEVEL_CONST_VAL("TOP-LEVEL CONST-VAL"),
+    TOP_LEVEL_VAL("TOP-LEVEL VAL"),
+    TOP_LEVEL_FUN("TOP-LEVEL FUN"),
+    TOP_LEVEL_CLASS("TOP-LEVEL CLASS"),
+    CLASS_CONSTRUCTOR("CLASS_CONSTRUCTOR"),
+    NESTED_VAL("NESTED VAL"),
+    NESTED_FUN("NESTED FUN"),
+    NESTED_CLASS("NESTED CLASS"),
+    NESTED_INTERFACE("NESTED INTERFACE"),
+    COMPANION_OBJECT("COMPANION_OBJECT"),
+    TOP_LEVEL_INTERFACE("TOP-LEVEL INTERFACE"),
+    TYPE_ALIAS("TYPE_ALIAS"),
+    ENUM_ENTRY("ENUM_ENTRY"),
+    ENUM_CLASS("ENUM_CLASS"),
+    MODULE("MODULE"),
+    UNKNOWN("UNKNOWN");
+
+    companion object {
+        val DeclarationDescriptor.declarationType: DeclarationType
+            get() = when (this) {
+                is ClassDescriptor -> {
+                    if (isCompanionObject) {
+                        COMPANION_OBJECT
+                    } else when (kind) {
+                        ClassKind.ENUM_CLASS -> ENUM_CLASS
+                        ClassKind.ENUM_ENTRY -> ENUM_ENTRY
+                        ClassKind.INTERFACE -> if (DescriptorUtils.isTopLevelDeclaration(this)) TOP_LEVEL_INTERFACE else NESTED_INTERFACE
+                        else -> if (DescriptorUtils.isTopLevelDeclaration(this)) TOP_LEVEL_CLASS else NESTED_CLASS
+                    }
+                }
+                is TypeAliasDescriptor -> TYPE_ALIAS
+                is ClassConstructorDescriptor -> CLASS_CONSTRUCTOR
+                is FunctionDescriptor -> if (DescriptorUtils.isTopLevelDeclaration(this)) TOP_LEVEL_FUN else NESTED_FUN
+                is PropertyDescriptor -> if (DescriptorUtils.isTopLevelDeclaration(this)) {
+                    if (isConst) TOP_LEVEL_CONST_VAL else TOP_LEVEL_VAL
+                } else NESTED_VAL
+                is ModuleDescriptor -> MODULE
+                else -> UNKNOWN
+            }
+    }
+}
@@ -0,0 +1,168 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.stats
+
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.commonizer.stats.DeclarationType.Companion.declarationType
+import org.jetbrains.kotlin.descriptors.commonizer.utils.firstNonNull
+import org.jetbrains.kotlin.descriptors.commonizer.utils.fqNameWithTypeParameters
+import org.jetbrains.kotlin.konan.target.KonanTarget
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+
+/**
+ * Allows printing commonization statistics to the file system.
+ *
+ * Output format is defined in [RawStatsCollector.output].
+ *
+ * Header row: "FQ Name, Extension Receiver, Parameter Names, Parameter Types, Declaration Type, common, <platform1>, <platform2> [<platformN>...]"
+ *
+ * Possible values for "Declaration Type":
+ * - MODULE
+ * - CLASS
+ * - INTERFACE
+ * - OBJECT
+ * - COMPANION_OBJECT
+ * - ENUM_CLASS
+ * - ENUM_ENTRY
+ * - TYPE_ALIAS
+ * - CLASS_CONSTRUCTOR
+ * - FUN
+ * - VAL
+ *
+ * Possible values for "common" column:
+ * - L = declaration lifted up to common fragment
+ * - E = successfully commonized, expect declaration generated
+ * - "-" = no common declaration
+ *
+ * Possible values for each target platform column:
+ * - A = successfully commonized, actual declaration generated
+ * - O = not commonized, the declaration is as in the original library
+ * - "-" = no such declaration in the original library (or declaration has been lifted up)
+ *
+ * Example of output:
+
+FQ Name|Extension Receiver|Parameter Names|Parameter Types|Declaration Type|common|macos_x64|ios_x64
+<SystemConfiguration>||||MODULE|E|A|A
+platform.SystemConfiguration.SCPreferencesContext||||CLASS|E|A|A
+platform.SystemConfiguration.SCPreferencesContext.Companion||||COMPANION_OBJECT|E|A|A
+platform.SystemConfiguration.SCNetworkConnectionContext||||CLASS|E|A|A
+platform.SystemConfiguration.SCNetworkConnectionContext.Companion||||COMPANION_OBJECT|E|A|A
+platform.SystemConfiguration.SCDynamicStoreRefVar||||TYPE_ALIAS|-|O|O
+platform.SystemConfiguration.SCVLANInterfaceRef||||TYPE_ALIAS|-|O|O
+
+ */
+class RawStatsCollector(
+    private val targets: List<KonanTarget>,
+    private val output: StatsOutput
+) : StatsCollector {
+    private var headerWritten = false
+
+    override fun logStats(result: List<DeclarationDescriptor?>) {
+        if (!headerWritten) {
+            writeHeader()
+            headerWritten = true
+        }
+
+        val firstNotNull = result.firstNonNull()
+        val lastIsNull = result.last() == null
+
+        val statsRow = RawStatsRow(
+            dimension = targets.size,
+            fqName = if (firstNotNull is ModuleDescriptor) firstNotNull.name.asString() else firstNotNull.fqNameSafe.asString(),
+            declarationType = firstNotNull.declarationType
+        )
+
+        // extension receiver
+        if (firstNotNull is PropertyDescriptor || firstNotNull is SimpleFunctionDescriptor) {
+            statsRow.extensionReceiver =
+                (firstNotNull as CallableDescriptor).extensionReceiverParameter?.type?.fqNameWithTypeParameters.orEmpty()
+        }
+
+        if (firstNotNull is ConstructorDescriptor || firstNotNull is SimpleFunctionDescriptor) {
+            val functionDescriptor = (firstNotNull as FunctionDescriptor)
+            // parameter names
+            statsRow.parameterNames = functionDescriptor.valueParameters.joinToString { it.name.asString() }
+            // parameter types
+            statsRow.parameterTypes = functionDescriptor.valueParameters.joinToString { it.type.fqNameWithTypeParameters }
+        }
+
+        var isLiftedUp = !lastIsNull
+        for (index in 0 until result.size - 1) {
+            statsRow.platform += when {
+                result[index] == null -> PlatformDeclarationStatus.ABSENT
+                lastIsNull -> PlatformDeclarationStatus.ORIGINAL
+                else -> {
+                    isLiftedUp = false
+                    PlatformDeclarationStatus.ACTUAL
+                }
+            }
+        }
+
+        statsRow.common = when {
+            isLiftedUp -> CommonDeclarationStatus.LIFTED_UP
+            lastIsNull -> CommonDeclarationStatus.ABSENT
+            else -> CommonDeclarationStatus.EXPECT
+        }
+
+        output.writeRow(statsRow)
+    }
+
+    override fun close() {
+        output.close()
+    }
+
+    private fun writeHeader() {
+        output.writeHeader(RawStatsHeader(targets.map { it.name }))
+    }
+
+    class RawStatsHeader(
+        private val targetNames: List<String>
+    ) : StatsOutput.StatsHeader {
+        override fun toList(): List<String> = mutableListOf<String>().apply {
+            this += "FQ Name"
+            this += "Extension Receiver"
+            this += "Parameter Names"
+            this += "Parameter Types"
+            this += "Declaration Type"
+            this += "common"
+            this += targetNames
+        }
+    }
+
+    class RawStatsRow(
+        dimension: Int,
+        val fqName: String,
+        val declarationType: DeclarationType
+    ) : StatsOutput.StatsRow {
+        var extensionReceiver: String = ""
+        var parameterNames: String = ""
+        var parameterTypes: String = ""
+        lateinit var common: CommonDeclarationStatus
+        val platform: MutableList<PlatformDeclarationStatus> = ArrayList(dimension)
+
+        override fun toList(): List<String> = mutableListOf<String>().apply {
+            this += fqName
+            this += extensionReceiver
+            this += parameterNames
+            this += parameterTypes
+            this += declarationType.alias
+            this += common.alias.toString()
+            platform.forEach { this += it.alias.toString() }
+        }
+    }
+
+    enum class CommonDeclarationStatus(val alias: Char) {
+        LIFTED_UP('L'),
+        EXPECT('E'),
+        ABSENT('-')
+    }
+
+    enum class PlatformDeclarationStatus(val alias: Char) {
+        ACTUAL('A'),
+        ORIGINAL('O'),
+        ABSENT('-')
+    }
+}
@@ -1,13 +1,13 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

-package org.jetbrains.kotlin.descriptors.commonizer
+package org.jetbrains.kotlin.descriptors.commonizer.stats

 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import java.io.Closeable

 interface StatsCollector : Closeable {
-    fun logStats(output: List<DeclarationDescriptor?>)
+    fun logStats(result: List<DeclarationDescriptor?>)
 }
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.stats
+
+import java.io.Closeable
+import java.io.File
+import java.io.PrintWriter
+
+interface StatsOutput : Closeable {
+    interface StatsHeader {
+        fun toList(): List<String>
+    }
+
+    interface StatsRow {
+        fun toList(): List<String>
+    }
+
+    fun writeHeader(header: StatsHeader)
+    fun writeRow(row: StatsRow)
+}
+
+class FileStatsOutput(directory: File, baseName: String) : StatsOutput {
+    init {
+        directory.mkdirs()
+    }
+
+    private val writer: PrintWriter = directory.resolve("${baseName}_stats.csv").printWriter()
+    private var width: Int = 0
+
+    override fun writeHeader(header: StatsOutput.StatsHeader) {
+        check(width == 0)
+        val headerItems = header.toList()
+        require(headerItems.isNotEmpty())
+
+        width = headerItems.size
+        headerItems.joinTo(writer, separator = "|", postfix = "\n")
+    }
+
+    override fun writeRow(row: StatsOutput.StatsRow) {
+        check(width > 0)
+        val rowItems = row.toList()
+        require(rowItems.size == width)
+
+        rowItems.joinTo(writer, separator = "|", postfix = "\n")
+    }
+
+    override fun close() {
+        writer.close()
+    }
+}