JVM IR: run FileClass & ExpectDeclarationsRemoving phases on whole module

Since we now generate file classes even for IR loaded from dependencies
(see 3a9b94235f) to simplify code in certain lowerings, it makes sense
to do that for all source files together before any meaningful
lowerings. The easiest way to do so is to make FileClassLowering a
module-wide phase.

ExpectDeclarationsRemoveLowering is now also a module-wide phase because
it needs to be run before FileClassLowering (to avoid producing empty
facades for files that only contain `expect` declarations)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendFacade.kt

@@ -73,20 +73,18 @@ object JvmBackendFacade {
             facadeClassGenerator = ::facadeClassGenerator
         ).generateUnboundSymbolsAsDependencies()
 
-        val lower = JvmLower(context)
-
         for (irFile in irModuleFragment.files) {
-            try {
-                for (extension in IrGenerationExtension.getInstances(context.state.project)) {
-                    extension.generate(irFile, context, context.state.bindingContext)
-                }
-
-                lower.lower(irFile)
-            } catch (e: Throwable) {
-                errorHandler.reportException(e, null) // TODO ktFile.virtualFile.url
+            for (extension in IrGenerationExtension.getInstances(context.state.project)) {
+                extension.generate(irFile, context, context.state.bindingContext)
             }
         }
 
+        try {
+            JvmLower(context).lower(irModuleFragment)
+        } catch (e: Throwable) {
+            errorHandler.reportException(e, null)
+        }
+
         for (irFile in irModuleFragment.files) {
             try {
                 for (loweredClass in irFile.declarations) {
@@ -98,7 +96,7 @@ object JvmBackendFacade {
                 }
                 state.afterIndependentPart()
             } catch (e: Throwable) {
-                errorHandler.reportException(e, null)
+                errorHandler.reportException(e, null) // TODO ktFile.virtualFile.url
             }
         }
     }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.backend.jvm.lower.*
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationWithName
 import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.util.PatchDeclarationParentsVisitor
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.load.java.JvmAbi
@@ -41,7 +42,7 @@ private val arrayConstructorPhase = makeIrFilePhase(
     description = "Transform `Array(size) { index -> value }` into a loop"
 )
 
-private val expectDeclarationsRemovingPhase = makeIrFilePhase(
+private val expectDeclarationsRemovingPhase = makeIrModulePhase(
     ::ExpectDeclarationsRemoveLowering,
     name = "ExpectDeclarationsRemoving",
     description = "Remove expect declaration from module fragment"
@@ -90,81 +91,84 @@ private val innerClassesPhase = makeIrFilePhase(
     prerequisite = setOf(localDeclarationsPhase)
 )
 
-val jvmPhases = namedIrFilePhase<JvmBackendContext>(
+private val jvmFilePhases = inventNamesForLocalClassesPhase then
+
+        kCallableNamePropertyPhase then
+        arrayConstructorPhase then
+
+        lateinitPhase then
+
+        moveOrCopyCompanionObjectFieldsPhase then
+        inlineCallableReferenceToLambdaPhase then
+        propertyReferencePhase then
+        constPhase then
+        propertiesToFieldsPhase then
+        propertiesPhase then
+        renameFieldsPhase then
+        annotationPhase then
+        tailrecPhase then
+
+        jvmInlineClassPhase then
+
+        sharedVariablesPhase then
+
+        makePatchParentsPhase(1) then
+
+        enumWhenPhase then
+        singletonReferencesPhase then
+        localDeclarationsPhase then
+        defaultArgumentStubPhase then
+
+        interfacePhase then
+        interfaceDelegationPhase then
+        interfaceSuperCallsPhase then
+
+        singleAbstractMethodPhase then
+        addContinuationPhase then
+        callableReferencePhase then
+        functionNVarargInvokePhase then
+
+        innerClassesPhase then
+        innerClassConstructorCallsPhase then
+        forLoopsPhase then
+
+        makePatchParentsPhase(2) then
+
+        enumClassPhase then
+        objectClassPhase then
+        makeInitializersPhase(JvmLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, true) then
+        syntheticAccessorPhase then
+        collectionStubMethodLowering then
+        bridgePhase then
+        jvmOverloadsAnnotationPhase then
+        jvmDefaultConstructorPhase then
+        jvmStaticAnnotationPhase then
+        staticDefaultFunctionPhase then
+
+        toArrayPhase then
+        flattenStringConcatenationPhase then
+        foldConstantLoweringPhase then
+        computeStringTrimPhase then
+        jvmBuiltinOptimizationLoweringPhase then
+        additionalClassAnnotationPhase then
+
+        recordNamesForKotlinTypeMapperPhase then
+
+        // should be last transformation
+        removeDeclarationsThatWouldBeInlined then
+        makePatchParentsPhase(3)
+
+val jvmPhases = namedIrModulePhase(
     name = "IrLowering",
     description = "IR lowering",
     lower = expectDeclarationsRemovingPhase then
             fileClassPhase then
-            inventNamesForLocalClassesPhase then
-            kCallableNamePropertyPhase then
-            arrayConstructorPhase then
-
-            lateinitPhase then
-
-            moveOrCopyCompanionObjectFieldsPhase then
-            inlineCallableReferenceToLambdaPhase then
-            propertyReferencePhase then
-            constPhase then
-            propertiesToFieldsPhase then
-            propertiesPhase then
-            renameFieldsPhase then
-            annotationPhase then
-            tailrecPhase then
-
-            jvmInlineClassPhase then
-
-            sharedVariablesPhase then
-
-            makePatchParentsPhase(1) then
-
-            enumWhenPhase then
-            singletonReferencesPhase then
-            localDeclarationsPhase then
-            defaultArgumentStubPhase then
-
-            interfacePhase then
-            interfaceDelegationPhase then
-            interfaceSuperCallsPhase then
-
-            singleAbstractMethodPhase then
-            addContinuationPhase then
-            callableReferencePhase then
-            functionNVarargInvokePhase then
-
-            innerClassesPhase then
-            innerClassConstructorCallsPhase then
-            forLoopsPhase then
-
-            makePatchParentsPhase(2) then
-
-            enumClassPhase then
-            objectClassPhase then
-            makeInitializersPhase(JvmLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, true) then
-            syntheticAccessorPhase then
-            collectionStubMethodLowering then
-            bridgePhase then
-            jvmOverloadsAnnotationPhase then
-            jvmDefaultConstructorPhase then
-            jvmStaticAnnotationPhase then
-            staticDefaultFunctionPhase then
-
-            toArrayPhase then
-            flattenStringConcatenationPhase then
-            foldConstantLoweringPhase then
-            computeStringTrimPhase then
-            jvmBuiltinOptimizationLoweringPhase then
-            additionalClassAnnotationPhase then
-
-            recordNamesForKotlinTypeMapperPhase then
-
-            // should be last transformation
-            removeDeclarationsThatWouldBeInlined then
-            makePatchParentsPhase(3)
+            performByIrFile(lower = jvmFilePhases)
 )
 
 class JvmLower(val context: JvmBackendContext) {
-    fun lower(irFile: IrFile) {
+    fun lower(irModuleFragment: IrModuleFragment) {
         // TODO run lowering passes as callbacks in bottom-up visitor
-        jvmPhases.invokeToplevel(context.phaseConfig, context, irFile)
+        jvmPhases.invokeToplevel(context.phaseConfig, context, irModuleFragment)
     }
 }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/FileClassLowering.kt

@@ -19,7 +19,7 @@ package org.jetbrains.kotlin.backend.jvm.lower
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.descriptors.WrappedClassDescriptor
 import org.jetbrains.kotlin.backend.common.ir.createImplicitParameterDeclarationWithWrappedDescriptor
-import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
+import org.jetbrains.kotlin.backend.common.phaser.makeIrModulePhase
 import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.codegen.AsmUtil
 import org.jetbrains.kotlin.descriptors.ClassKind
@@ -33,15 +33,17 @@ import org.jetbrains.kotlin.psi2ir.PsiSourceManager
 import org.jetbrains.kotlin.resolve.source.KotlinSourceElement
 import java.util.*
 
-internal val fileClassPhase = makeIrFilePhase(
+internal val fileClassPhase = makeIrModulePhase(
     ::FileClassLowering,
     name = "FileClass",
     description = "Put file level function and property declaration into a class",
     stickyPostconditions = setOf(::checkAllFileLevelDeclarationsAreClasses)
 )
 
-private fun checkAllFileLevelDeclarationsAreClasses(irFile: IrFile) {
-    assert(irFile.declarations.all { it is IrClass })
+private fun checkAllFileLevelDeclarationsAreClasses(irModuleFragment: IrModuleFragment) {
+    assert(irModuleFragment.files.all { irFile ->
+        irFile.declarations.all { it is IrClass }
+    })
 }
 
 private class FileClassLowering(val context: JvmBackendContext) : FileLoweringPass {