JVM_IR: extract boolean-valued DFS on IR elements into a helper

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

@@ -42,6 +42,7 @@ import org.jetbrains.kotlin.ir.types.impl.IrStarProjectionImpl
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.load.java.JavaDescriptorVisibilities
 import org.jetbrains.kotlin.load.java.JvmAbi
@@ -404,3 +405,15 @@ fun IrFile.getKtFile(): KtFile? =
 
 fun IrType.isInlineClassType(): Boolean =
     erasedUpperBound.isInline
+
+inline fun IrElement.hasChild(crossinline block: (IrElement) -> Boolean): Boolean {
+    var result = false
+    acceptChildren(object : IrElementVisitorVoid {
+        override fun visitElement(element: IrElement) = when {
+            result -> Unit
+            block(element) -> result = true
+            else -> element.acceptChildren(this, null)
+        }
+    }, null)
+    return result
+}

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

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
 import org.jetbrains.kotlin.backend.jvm.codegen.parentClassId
 import org.jetbrains.kotlin.backend.jvm.ir.createJvmIrBuilder
+import org.jetbrains.kotlin.backend.jvm.ir.hasChild
 import org.jetbrains.kotlin.backend.jvm.ir.irArrayOf
 import org.jetbrains.kotlin.backend.jvm.ir.needsAccessor
 import org.jetbrains.kotlin.backend.jvm.lower.FunctionReferenceLowering.Companion.calculateOwner
@@ -28,7 +29,6 @@ import org.jetbrains.kotlin.codegen.inline.loadCompiledInlineFunction
 import org.jetbrains.kotlin.codegen.optimization.nullCheck.usesLocalExceptParameterNullCheck
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.builders.*
@@ -47,7 +47,6 @@ import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
 import org.jetbrains.kotlin.ir.types.typeWith
 import org.jetbrains.kotlin.ir.util.*
-import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.load.java.JavaDescriptorVisibilities
 import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.kotlin.name.Name
@@ -274,17 +273,7 @@ private class PropertyReferenceLowering(val context: JvmBackendContext) : IrElem
             return loadCompiledInlineFunction(containerId, signature.asmMethod, isSuspend, hasMangledReturnType, context.state)
                 .node.usesLocalExceptParameterNullCheck(localIndex)
         }
-
+        return hasChild { it is IrGetValue && it.symbol == valueParameters[index].symbol }
-        var result = false
-        accept(object : IrElementVisitorVoid {
-            override fun visitElement(element: IrElement) =
-                if (result) Unit else element.acceptChildren(this, null)
-
-            override fun visitGetValue(expression: IrGetValue) {
-                if (expression.symbol == valueParameters[index].symbol) result = true
-            }
-        }, null)
-        return result
     }
 
     // Assuming that the only functions that take PROPERTY_REFERENCE_FOR_DELEGATE-kind references are getValue,
@@ -292,18 +281,14 @@ private class PropertyReferenceLowering(val context: JvmBackendContext) : IrElem
     private val usesPropertyParameterCache = ConcurrentHashMap<IrSymbol, Boolean>()
 
     override fun visitCall(expression: IrCall): IrExpression {
-        if (!expression.symbol.owner.isInline) {
+        // Don't generate entries in `$$delegatedProperties` if they won't be used for anything. This is only possible
-            // Can't optimize if the function can start using the reference later.
+        // for inline functions, since for non-inline ones we need to provide some non-null value, and if they're not
-            // TODO: optimize if callee is in the same file? this requires removing the null check from it,
+        // in the same file, they can start using it without forcing a recompilation of this file.
-            //       or at least providing *some* non-null fake property value.
+        if (!expression.symbol.owner.isInline) return super.visitCall(expression)
-            return super.visitCall(expression)
-        }
-
         for (index in expression.symbol.owner.valueParameters.indices) {
             val value = expression.getValueArgument(index)
             if (value is IrCallableReference<*> && value.origin == IrStatementOrigin.PROPERTY_REFERENCE_FOR_DELEGATE) {
                 if (!usesPropertyParameterCache.getOrPut(expression.symbol) { expression.symbol.owner.usesParameter(index) }) {
-                    // Don't generate an entry in `$$delegatedProperties`, it won't be used anyway.
                     expression.putValueArgument(index, IrConstImpl.constNull(value.startOffset, value.endOffset, value.type))
                 }
             }

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

@@ -10,11 +10,13 @@ import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
 import org.jetbrains.kotlin.backend.common.ir.*
 import org.jetbrains.kotlin.backend.common.lower.LocalDeclarationsLowering
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
+import org.jetbrains.kotlin.backend.common.lower.parents
 import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
 import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
 import org.jetbrains.kotlin.backend.jvm.codegen.isReadOfCrossinline
 import org.jetbrains.kotlin.backend.jvm.ir.IrInlineReferenceLocator
+import org.jetbrains.kotlin.backend.jvm.ir.hasChild
 import org.jetbrains.kotlin.codegen.coroutines.COROUTINE_LABEL_FIELD_NAME
 import org.jetbrains.kotlin.codegen.coroutines.INVOKE_SUSPEND_METHOD_NAME
 import org.jetbrains.kotlin.codegen.coroutines.SUSPEND_FUNCTION_COMPLETION_PARAMETER_NAME
@@ -47,25 +49,8 @@ internal val suspendLambdaPhase = makeIrFilePhase(
 )
 
 private fun IrFunction.capturesCrossinline(): Boolean {
-    var result = false
+    val parents = parents.toSet()
-    accept(object : IrElementVisitorVoid {
+    return hasChild { it is IrGetValue && it.isReadOfCrossinline() && it.symbol.owner.parent in parents }
-        override fun visitElement(element: IrElement) {
-            if (!result) element.acceptChildren(this, null)
-        }
-
-        override fun visitFunction(declaration: IrFunction) {
-            functions.add(declaration)
-            super.visitFunction(declaration)
-            functions.remove(declaration)
-        }
-
-        override fun visitGetValue(expression: IrGetValue) {
-            result = result || (expression.isReadOfCrossinline() && expression.symbol.owner.parent !in functions)
-        }
-
-        private val functions = mutableSetOf<IrFunction>()
-    }, null)
-    return result
 }
 
 internal abstract class SuspendLoweringUtils(protected val context: JvmBackendContext) {