[K/N] More clear separation of CAdapterGenerator

Separated CAdapterBindingsBuilder into
CAdapterCodegen and CAdapterApiExporter. It makes C export much more
comprehensible and allows to split it into more clear phases.

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt

@@ -108,8 +108,7 @@ internal val buildCExportsPhase = konanUnitPhase(
         op = {
             val prefix = config.fullExportedNamePrefix.replace("-|\\.".toRegex(), "_")
             val cAdapterTypeTranslator = CAdapterTypeTranslator(prefix, this.builtIns)
-            this.cAdapterExportedElements = CAdapterGenerator(this, this.moduleDescriptor, cAdapterTypeTranslator)
+            this.cAdapterExportedElements = CAdapterGenerator(this, cAdapterTypeTranslator).buildExports(this.moduleDescriptor)
-                    .buildExports(this.symbolTable!!)
         },
         name = "BuildCExports",
         description = "Build C exports",

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cexport/CAdapterApiExporter.kt

@@ -5,44 +5,31 @@
 
 package org.jetbrains.kotlin.backend.konan.cexport
 
-import kotlinx.cinterop.cValuesOf
+import org.jetbrains.kotlin.backend.konan.NativeGenerationState
-import llvm.*
-import org.jetbrains.kotlin.backend.common.pop
-import org.jetbrains.kotlin.backend.konan.llvm.*
-import org.jetbrains.kotlin.backend.konan.llvm.CodeGenerator
-import org.jetbrains.kotlin.backend.konan.llvm.ContextUtils
-import org.jetbrains.kotlin.backend.konan.llvm.ExceptionHandler
-import org.jetbrains.kotlin.backend.konan.llvm.Lifetime
-import org.jetbrains.kotlin.backend.konan.llvm.addLlvmFunctionWithDefaultAttributes
-import org.jetbrains.kotlin.backend.konan.llvm.generateFunction
-import org.jetbrains.kotlin.backend.konan.lower.getObjectClassInstanceFunction
 import org.jetbrains.kotlin.builtins.UnsignedType
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.findClassAcrossModuleDependencies
-import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrEnumEntry
-import org.jetbrains.kotlin.ir.declarations.IrFunction
-import org.jetbrains.kotlin.ir.util.isOverridable
 import org.jetbrains.kotlin.konan.target.Family
-import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.typeUtil.isNothing
 import org.jetbrains.kotlin.types.typeUtil.isUnit
 import org.jetbrains.kotlin.types.typeUtil.makeNullable
 import java.io.PrintWriter
 
-internal class CAdapterBindingsBuilder(
+/**
-        val codegen: CodeGenerator,
+ * Third phase of C export:
-        val elements: CAdapterExportedElements,
+ *  1. Create a C++ file with runtime bindings
-) : ContextUtils {
+ *  2. Create a header file with API
-    override val generationState = codegen.generationState
+ *  3. (MinGW only) create EXPORTS def file.
-
+ */
+internal class CAdapterApiExporter(
+        private val generationState: NativeGenerationState,
+        private val elements: CAdapterExportedElements,
+) {
     private val typeTranslator = elements.typeTranslator
     private val builtIns = elements.typeTranslator.builtIns
-    private val scopes = elements.scopes
 
-    internal val prefix = context.config.fullExportedNamePrefix.replace("-|\\.".toRegex(), "_")
+    private val prefix = elements.typeTranslator.prefix
     private lateinit var outputStreamWriter: PrintWriter
 
     // Primitive built-ins and unsigned types
@@ -57,92 +44,6 @@ internal class CAdapterBindingsBuilder(
         builtIns.builtInsModule.findClassAcrossModuleDependencies(it.classId)!!.defaultType
     }
 
-    fun build() {
-        val top = scopes.pop()
-        assert(scopes.isEmpty() && top.kind == ScopeKind.TOP)
-
-        // Now, let's generate C world adapters for all functions.
-        top.generateCAdapters(::buildCAdapter)
-
-        // Then generate data structure, describing generated adapters.
-        makeGlobalStruct(top)
-    }
-
-    private fun buildCAdapter(exportedElement: ExportedElement): Unit = with(exportedElement) {
-        when {
-            isFunction -> {
-                val function = declaration as FunctionDescriptor
-                val irFunction = irSymbol.owner as IrFunction
-                cname = "_konan_function_${owner.nextFunctionIndex()}"
-                val llvmCallable = codegen.llvmFunction(irFunction)
-                // If function is virtual, we need to resolve receiver properly.
-                val bridge = generateFunction(codegen, llvmCallable.functionType, cname) {
-                    val callee = if (!DescriptorUtils.isTopLevelDeclaration(function) &&
-                            irFunction.isOverridable
-                    ) {
-                        val receiver = param(0)
-                        lookupVirtualImpl(receiver, irFunction)
-                    } else {
-                        // KT-45468: Alias insertion may not be handled by LLVM properly, in case callee is in the cache.
-                        // Hence, insert not an alias but a wrapper, hoping it will be optimized out later.
-                        llvmCallable
-                    }
-
-                    val numParams = LLVMCountParams(llvmCallable.llvmValue)
-                    val args = (0 until numParams).map { index -> param(index) }
-                    callee.attributeProvider.addFunctionAttributes(this.function)
-                    val result = call(callee, args, exceptionHandler = ExceptionHandler.Caller, verbatim = true)
-                    ret(result)
-                }
-                LLVMSetLinkage(bridge, LLVMLinkage.LLVMExternalLinkage)
-            }
-            isClass -> {
-                val irClass = irSymbol.owner as IrClass
-                cname = "_konan_function_${owner.nextFunctionIndex()}"
-                // Produce type getter.
-                val getTypeFunction = addLlvmFunctionWithDefaultAttributes(
-                        context,
-                        llvm.module,
-                        "${cname}_type",
-                        kGetTypeFuncType
-                )
-                val builder = LLVMCreateBuilderInContext(llvm.llvmContext)!!
-                val bb = LLVMAppendBasicBlockInContext(llvm.llvmContext, getTypeFunction, "")!!
-                LLVMPositionBuilderAtEnd(builder, bb)
-                LLVMBuildRet(builder, irClass.typeInfoPtr.llvm)
-                LLVMDisposeBuilder(builder)
-                // Produce instance getter if needed.
-                if (isSingletonObject) {
-                    generateFunction(codegen, kGetObjectFuncType, "${cname}_instance") {
-                        val value = call(
-                                codegen.llvmFunction(context.getObjectClassInstanceFunction(irClass)),
-                                emptyList(),
-                                Lifetime.GLOBAL,
-                                ExceptionHandler.Caller,
-                                false,
-                                returnSlot
-                        )
-                        ret(value)
-                    }
-                }
-            }
-            isEnumEntry -> {
-                // Produce entry getter.
-                cname = "_konan_function_${owner.nextFunctionIndex()}"
-                generateFunction(codegen, kGetObjectFuncType, cname) {
-                    val irEnumEntry = irSymbol.owner as IrEnumEntry
-                    val value = getEnumEntry(irEnumEntry, ExceptionHandler.Caller)
-                    ret(value)
-                }
-            }
-        }
-    }
-
-    private val kGetTypeFuncType = LLVMFunctionType(codegen.kTypeInfoPtr, null, 0, 0)!!
-
-    // Abstraction leak for slot :(.
-    private val kGetObjectFuncType = LLVMFunctionType(codegen.kObjHeaderPtr, cValuesOf(codegen.kObjHeaderPtrPtr), 1, 0)!!
-
     private fun output(string: String, indent: Int = 0) {
         if (indent != 0) outputStreamWriter.print("  " * indent)
         outputStreamWriter.println(string)
@@ -249,9 +150,11 @@ internal class CAdapterBindingsBuilder(
                 }
     }
 
-    val exportedSymbols = mutableListOf<String>()
+    private val exportedSymbols = mutableListOf<String>()
 
-    private fun makeGlobalStruct(top: ExportedElementScope) {
+    // TODO: Pass temp and output files explicitly and untie from `NativeGenerationState`.
+    fun makeGlobalStruct() {
+        val top = elements.scopes.first()
         val headerFile = generationState.outputFiles.cAdapterHeader
         outputStreamWriter = headerFile.printWriter()
 
@@ -285,7 +188,7 @@ internal class CAdapterBindingsBuilder(
         output("typedef double             ${prefix}_KDouble;")
 
         val typedef_KVector128 = "typedef float __attribute__ ((__vector_size__ (16))) ${prefix}_KVector128;"
-        if (context.config.target.family == Family.MINGW) {
+        if (generationState.config.target.family == Family.MINGW) {
             // Separate `output` for each line to ensure Windows EOL (LFCR), otherwise generated file will have inconsistent line ending.
             output("#ifndef _MSC_VER")
             output(typedef_KVector128)
@@ -476,7 +379,7 @@ internal class CAdapterBindingsBuilder(
         output("RUNTIME_USED ${prefix}_ExportedSymbols* $exportedSymbol(void) { return &__konan_symbols;}")
         outputStreamWriter.close()
 
-        if (context.config.target.family == Family.MINGW) {
+        if (generationState.config.target.family == Family.MINGW) {
             outputStreamWriter = generationState.outputFiles
                     .cAdapterDef
                     .printWriter()

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cexport/CAdapterCodegen.kt

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2010-2022 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.backend.konan.cexport
+
+import kotlinx.cinterop.cValuesOf
+import llvm.*
+import org.jetbrains.kotlin.backend.konan.NativeGenerationState
+import org.jetbrains.kotlin.backend.konan.llvm.*
+import org.jetbrains.kotlin.backend.konan.llvm.CodeGenerator
+import org.jetbrains.kotlin.backend.konan.llvm.ContextUtils
+import org.jetbrains.kotlin.backend.konan.llvm.ExceptionHandler
+import org.jetbrains.kotlin.backend.konan.llvm.Lifetime
+import org.jetbrains.kotlin.backend.konan.llvm.addLlvmFunctionWithDefaultAttributes
+import org.jetbrains.kotlin.backend.konan.llvm.generateFunction
+import org.jetbrains.kotlin.backend.konan.lower.getObjectClassInstanceFunction
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrEnumEntry
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.util.isOverridable
+import org.jetbrains.kotlin.resolve.DescriptorUtils
+
+/**
+ * Second phase of C Export: build bitcode bridges from C wrappers to Kotlin functions.
+ */
+internal class CAdapterCodegen(
+    private val codegen: CodeGenerator,
+    override val generationState: NativeGenerationState,
+) : ContextUtils {
+
+    fun buildAllAdaptersRecursively(elements: CAdapterExportedElements) {
+        val top = elements.scopes.single()
+        assert(top.kind == ScopeKind.TOP)
+        top.generateCAdapters(this::buildCAdapter)
+    }
+
+    private fun ExportedElementScope.generateCAdapters(builder: (ExportedElement) -> Unit) {
+        this.elements.forEach { builder(it) }
+        this.scopes.forEach { it.generateCAdapters(builder) }
+    }
+
+    private fun buildCAdapter(exportedElement: ExportedElement): Unit = with(exportedElement) {
+        when {
+            isFunction -> {
+                val function = declaration as FunctionDescriptor
+                val irFunction = irSymbol.owner as IrFunction
+                cname = "_konan_function_${owner.nextFunctionIndex()}"
+                val llvmCallable = codegen.llvmFunction(irFunction)
+                // If function is virtual, we need to resolve receiver properly.
+                val bridge = generateFunction(codegen, llvmCallable.functionType, cname) {
+                    val callee = if (!DescriptorUtils.isTopLevelDeclaration(function) &&
+                        irFunction.isOverridable
+                    ) {
+                        val receiver = param(0)
+                        lookupVirtualImpl(receiver, irFunction)
+                    } else {
+                        // KT-45468: Alias insertion may not be handled by LLVM properly, in case callee is in the cache.
+                        // Hence, insert not an alias but a wrapper, hoping it will be optimized out later.
+                        llvmCallable
+                    }
+
+                    val numParams = LLVMCountParams(llvmCallable.llvmValue)
+                    val args = (0 until numParams).map { index -> param(index) }
+                    callee.attributeProvider.addFunctionAttributes(this.function)
+                    val result = call(callee, args, exceptionHandler = ExceptionHandler.Caller, verbatim = true)
+                    ret(result)
+                }
+                LLVMSetLinkage(bridge, LLVMLinkage.LLVMExternalLinkage)
+            }
+            isClass -> {
+                val irClass = irSymbol.owner as IrClass
+                cname = "_konan_function_${owner.nextFunctionIndex()}"
+                // Produce type getter.
+                val getTypeFunction = addLlvmFunctionWithDefaultAttributes(
+                    context,
+                    llvm.module,
+                    "${cname}_type",
+                    kGetTypeFuncType
+                )
+                val builder = LLVMCreateBuilderInContext(llvm.llvmContext)!!
+                val bb = LLVMAppendBasicBlockInContext(llvm.llvmContext, getTypeFunction, "")!!
+                LLVMPositionBuilderAtEnd(builder, bb)
+                LLVMBuildRet(builder, irClass.typeInfoPtr.llvm)
+                LLVMDisposeBuilder(builder)
+                // Produce instance getter if needed.
+                if (isSingletonObject) {
+                    generateFunction(codegen, kGetObjectFuncType, "${cname}_instance") {
+                        val value = call(
+                            codegen.llvmFunction(context.getObjectClassInstanceFunction(irClass)),
+                            emptyList(),
+                            Lifetime.GLOBAL,
+                            ExceptionHandler.Caller,
+                            false,
+                            returnSlot
+                        )
+                        ret(value)
+                    }
+                }
+            }
+            isEnumEntry -> {
+                // Produce entry getter.
+                cname = "_konan_function_${owner.nextFunctionIndex()}"
+                generateFunction(codegen, kGetObjectFuncType, cname) {
+                    val irEnumEntry = irSymbol.owner as IrEnumEntry
+                    val value = getEnumEntry(irEnumEntry, ExceptionHandler.Caller)
+                    ret(value)
+                }
+            }
+        }
+    }
+
+    private val kGetTypeFuncType = LLVMFunctionType(codegen.kTypeInfoPtr, null, 0, 0)!!
+
+    // Abstraction leak for slot :(.
+    private val kGetObjectFuncType = LLVMFunctionType(codegen.kObjHeaderPtr, cValuesOf(codegen.kObjHeaderPtrPtr), 1, 0)!!
+}

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cexport/CAdapterCompile.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.konan.exec.*
 import org.jetbrains.kotlin.konan.target.*
 import org.jetbrains.kotlin.konan.file.*
 
+// Fourth phase of C export: compile runtime bindings to bitcode.
 fun produceCAdapterBitcode(clang: ClangArgs, cppFileName: String, bitcodeFileName: String) {
     val clangCommand = clang.clangCXX("-std=c++17", cppFileName, "-emit-llvm", "-c", "-o", bitcodeFileName)
     Command(clangCommand).execute()

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/cexport/CAdapterGenerator.kt

@@ -5,26 +5,24 @@
 
 package org.jetbrains.kotlin.backend.konan.cexport
 
-import llvm.*
 import org.jetbrains.kotlin.backend.common.descriptors.allParameters
 import org.jetbrains.kotlin.backend.common.pop
 import org.jetbrains.kotlin.backend.common.push
 import org.jetbrains.kotlin.backend.konan.*
 import org.jetbrains.kotlin.backend.konan.driver.phases.PsiToIrContext
-import org.jetbrains.kotlin.backend.konan.llvm.*
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
-import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.referenceFunction
-import org.jetbrains.kotlin.konan.target.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.isChildOf
 import org.jetbrains.kotlin.resolve.DescriptorUtils
-import org.jetbrains.kotlin.resolve.annotations.*
+import org.jetbrains.kotlin.resolve.annotations.argumentValue
-import org.jetbrains.kotlin.resolve.descriptorUtil.*
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.resolve.descriptorUtil.isEffectivelyPublicApi
+import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.typeUtil.*
+import org.jetbrains.kotlin.types.typeUtil.isUnit
 
 internal enum class ScopeKind {
     TOP,
@@ -96,11 +94,6 @@ internal class ExportedElementScope(val kind: ScopeKind, val name: String) {
         return "$kind: $name ${elements.joinToString(", ")} ${scopes.joinToString("\n")}"
     }
 
-    fun generateCAdapters(builder: (ExportedElement) -> Unit) {
-        elements.forEach { builder(it) }
-        scopes.forEach { it.generateCAdapters(builder) }
-    }
-
     // collects names of inner scopes to make sure function<->scope name clashes would be detected, and functions would be mangled with "_" suffix
     fun collectInnerScopeName(innerScope: ExportedElementScope) {
         scopeNames += innerScope.name
@@ -396,17 +389,18 @@ private fun ModuleDescriptor.getPackageFragments(): List<PackageFragmentDescript
             getPackage(it).fragments.filter { it.module == this }
         }
 
+/**
+ * First phase of C export: walk given declaration descriptors and create [CAdapterExportedElements] from them.
+ */
 internal class CAdapterGenerator(
         private val context: PsiToIrContext,
-        private val moduleDescriptor: ModuleDescriptor,
         private val typeTranslator: CAdapterTypeTranslator,
 ) : DeclarationDescriptorVisitor<Boolean, Void?> {
     private val scopes = mutableListOf<ExportedElementScope>()
     internal val prefix = typeTranslator.prefix
     private val paramNamesRecorded = mutableMapOf<String, Int>()
 
-    private var symbolTableOrNull: SymbolTable? = null
+    internal val symbolTable get() = context.symbolTable!!
-    internal val symbolTable get() = symbolTableOrNull!!
 
     internal fun paramsToUniqueNames(params: List<ParameterDescriptor>): Map<ParameterDescriptor, String> {
         paramNamesRecorded.clear()
@@ -536,17 +530,7 @@ internal class CAdapterGenerator(
 
     private val moduleDescriptors = mutableSetOf<ModuleDescriptor>()
 
-    fun buildExports(symbolTable: SymbolTable): CAdapterExportedElements {
+    fun buildExports(moduleDescriptor: ModuleDescriptor): CAdapterExportedElements {
-        this.symbolTableOrNull = symbolTable
-        try {
-            buildExports()
-            return CAdapterExportedElements(typeTranslator, scopes)
-        } finally {
-            this.symbolTableOrNull = null
-        }
-    }
-
-    private fun buildExports() {
         scopes.push(ExportedElementScope(ScopeKind.TOP, "kotlin"))
         moduleDescriptors += moduleDescriptor
         moduleDescriptors += moduleDescriptor.getExportedDependencies(context.config)
@@ -557,6 +541,7 @@ internal class CAdapterGenerator(
                 })
 
         moduleDescriptor.getPackage(FqName.ROOT).accept(this, null)
+        return CAdapterExportedElements(typeTranslator, scopes)
     }
 
     private val simpleNameMapping = mapOf(

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/driver/phases/CExport.kt

@@ -15,5 +15,5 @@ internal val BuildCExports = createSimpleNamedCompilerPhase<PsiToIrContext, Fron
 ) { context, input ->
     val prefix = context.config.fullExportedNamePrefix.replace("-|\\.".toRegex(), "_")
     val typeTranslator = CAdapterTypeTranslator(prefix, context.builtIns)
-    CAdapterGenerator(context, input.moduleDescriptor, typeTranslator).buildExports(context.symbolTable!!)
+    CAdapterGenerator(context, typeTranslator).buildExports(input.moduleDescriptor)
 }

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -10,7 +10,8 @@ import llvm.*
 import org.jetbrains.kotlin.backend.common.lower.coroutines.getOrCreateFunctionWithContinuationStub
 import org.jetbrains.kotlin.backend.common.lower.inline.InlinerExpressionLocationHint
 import org.jetbrains.kotlin.backend.konan.*
-import org.jetbrains.kotlin.backend.konan.cexport.CAdapterBindingsBuilder
+import org.jetbrains.kotlin.backend.konan.cexport.CAdapterApiExporter
+import org.jetbrains.kotlin.backend.konan.cexport.CAdapterCodegen
 import org.jetbrains.kotlin.backend.konan.cgen.CBridgeOrigin
 import org.jetbrains.kotlin.backend.konan.descriptors.*
 import org.jetbrains.kotlin.backend.konan.ir.*
@@ -327,7 +328,10 @@ internal class CodeGeneratorVisitor(val generationState: NativeGenerationState,
         }
     }
     private fun appendCAdapters() {
-        CAdapterBindingsBuilder(codegen, context.cAdapterExportedElements).build()
+        val elements = context.cAdapterExportedElements
+        CAdapterCodegen(codegen, generationState).buildAllAdaptersRecursively(elements)
+        // TODO: It is not a part of IrToBitcode. Maybe move it somewhere?
+        CAdapterApiExporter(generationState, elements).makeGlobalStruct()
     }
 
     private fun FunctionGenerationContext.initThreadLocalField(irField: IrField) {