Expect/actual support in klibs under -Xklib-mpp

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/Psi2IrTranslator.kt

@@ -17,16 +17,15 @@
 package org.jetbrains.kotlin.psi2ir
 
 import org.jetbrains.kotlin.config.LanguageVersionSettings
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.psi.KtFile
-import org.jetbrains.kotlin.psi2ir.generators.AnnotationGenerator
-import org.jetbrains.kotlin.psi2ir.generators.GeneratorContext
-import org.jetbrains.kotlin.psi2ir.generators.GeneratorExtensions
-import org.jetbrains.kotlin.psi2ir.generators.ModuleGenerator
+import org.jetbrains.kotlin.psi2ir.generators.*
 import org.jetbrains.kotlin.psi2ir.transformations.insertImplicitCasts
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.utils.SmartList
@@ -68,11 +67,13 @@ class Psi2IrTranslator(
     fun generateModuleFragment(
         context: GeneratorContext,
         ktFiles: Collection<KtFile>,
-        irProviders: List<IrProvider>
+        irProviders: List<IrProvider>,
+        expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>? = null
     ): IrModuleFragment {
         val moduleGenerator = ModuleGenerator(context)
         val irModule = moduleGenerator.generateModuleFragmentWithoutDependencies(ktFiles)
 
+        expectDescriptorToSymbol ?. let { referenceExpectsForUsedActuals(it, context.symbolTable, irModule) }
         irModule.patchDeclarationParents()
         postprocess(context, irModule)
         // do not generate unbound symbols before postprocessing,
@@ -81,6 +82,7 @@ class Psi2IrTranslator(
         irModule.computeUniqIdForDeclarations(context.symbolTable)
 
         moduleGenerator.generateUnboundSymbolsAsDependencies(irProviders)
+
         return irModule
     }
 

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ExpectDependencyGenerator.kt

@@ -0,0 +1,86 @@
+package org.jetbrains.kotlin.psi2ir.generators
+
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
+import org.jetbrains.kotlin.ir.types.classOrNull
+import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+import org.jetbrains.kotlin.ir.visitors.acceptVoid
+import org.jetbrains.kotlin.resolve.multiplatform.findExpects
+
+// Need to create unbound symbols for expects corresponding to actuals of the currently compiled module.
+// This is neccessary because there is no explicit links between expects and actuals
+// neither in descriptors nor in IR.
+fun referenceExpectsForUsedActuals(expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>, symbolTable: SymbolTable, irModule: IrModuleFragment) {
+    irModule.acceptVoid(object : IrElementVisitorVoid {
+
+        private fun <T> T.forEachExpect(body: (DeclarationDescriptor) -> Unit) where T: IrDeclaration {
+            this.descriptor.findExpects().forEach {
+                body(it)
+            }
+        }
+
+        override fun visitElement(element: IrElement) {
+            element.acceptChildrenVoid(this)
+        }
+        override fun visitClass(declaration: IrClass) {
+            declaration.forEachExpect {
+                val symbol = symbolTable.referenceClass(it as ClassDescriptor)
+                expectDescriptorToSymbol.put(it, symbol);
+                it.constructors.forEach {
+                    expectDescriptorToSymbol.put(it, symbolTable.referenceConstructor(it as ClassConstructorDescriptor))
+                }
+            }
+            super.visitDeclaration(declaration)
+        }
+        override fun visitSimpleFunction(declaration: IrSimpleFunction) {
+            declaration.forEachExpect {
+                val symbol = symbolTable.referenceSimpleFunction(it as FunctionDescriptor);
+                expectDescriptorToSymbol.put(it, symbol);
+            }
+            super.visitDeclaration(declaration)
+        }
+        override fun visitConstructor(declaration: IrConstructor) {
+            declaration.forEachExpect {
+                val symbol = symbolTable.referenceConstructor(it as ClassConstructorDescriptor)
+                expectDescriptorToSymbol.put(it, symbol);
+            
+            }
+            super.visitDeclaration(declaration)
+        }
+        override fun visitProperty(declaration: IrProperty) {
+            declaration.forEachExpect {
+                val symbol = symbolTable.referenceProperty(it as PropertyDescriptor)
+                expectDescriptorToSymbol.put(it, symbol);
+            }
+            super.visitDeclaration(declaration)
+        }
+        override fun visitEnumEntry(declaration: IrEnumEntry) {
+            declaration.forEachExpect {
+                val symbol = symbolTable.referenceEnumEntry(it as ClassDescriptor)
+                expectDescriptorToSymbol.put(it, symbol);
+
+            }
+            super.visitDeclaration(declaration)
+        }
+        override fun visitTypeAlias(declaration: IrTypeAlias) {
+            // Force actual type alias right hand side deserialization.
+            if (declaration.isActual) {
+                declaration.expandedType.classOrNull?.descriptor?.let { symbolTable.referenceClass(it) }
+            }
+
+            declaration.forEachExpect {
+                val symbol = when (it) {
+                    is ClassDescriptor -> symbolTable.referenceClass(it)
+                    else -> error("Unexpected expect for actual type alias: $it")
+                }
+                expectDescriptorToSymbol.put(it, symbol);
+
+            }
+            super.visitDeclaration(declaration)
+        }
+    })
+}

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt

@@ -22,11 +22,7 @@ import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.declarations.MetadataSource
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
-import org.jetbrains.kotlin.ir.util.ExternalDependenciesGenerator
-import org.jetbrains.kotlin.ir.util.IrDeserializer
-import org.jetbrains.kotlin.ir.util.IrProvider
-import org.jetbrains.kotlin.ir.util.StubGeneratorExtensions
-import org.jetbrains.kotlin.ir.util.generateTypicalIrProviderList
+import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.lazy.descriptors.findPackageFragmentForFile