[JS IR BE] Support bridges for special methods

Mostly reused from JVM IR lowering. Shared logic moved to common backend module.
2019-05-05 23:42:51 +03:00
parent ec6904afd1
commit 17178628fb
4 changed files with 125 additions and 63 deletions
@@ -0,0 +1,88 @@
+/*
+ * 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.backend.common.lower
+
+import org.jetbrains.kotlin.backend.common.CommonBackendContext
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
+import org.jetbrains.kotlin.ir.expressions.IrConstKind
+import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
+import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
+import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+
+class SpecialBridgeMethods(val context: CommonBackendContext) {
+    private data class SpecialMethodDescription(val kotlinFqClassName: FqName?, val name: Name, val arity: Int)
+
+    private fun makeDescription(classFqName: String, funName: String, arity: Int) =
+        SpecialMethodDescription(
+            FqName(classFqName),
+            Name.identifier(funName),
+            arity
+        )
+
+    private fun IrSimpleFunction.toDescription() = SpecialMethodDescription(
+        parentAsClass.fqNameWhenAvailable,
+        name,
+        valueParameters.size
+    )
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun constFalse(bridge: IrSimpleFunction) =
+        IrConstImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, context.irBuiltIns.booleanType, IrConstKind.Boolean, false)
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun constNull(bridge: IrSimpleFunction) =
+        IrConstImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, context.irBuiltIns.anyNType, IrConstKind.Null, null)
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun constMinusOne(bridge: IrSimpleFunction) =
+        IrConstImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, context.irBuiltIns.intType, IrConstKind.Int, -1)
+
+    private fun getSecondArg(bridge: IrSimpleFunction) =
+        IrGetValueImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, bridge.valueParameters[1].symbol)
+
+    private val SPECIAL_METHODS_WITH_DEFAULTS_MAP = mapOf<SpecialMethodDescription, (IrSimpleFunction) -> IrExpression>(
+        makeDescription("kotlin.collections.Collection", "contains", 1) to ::constFalse,
+        makeDescription("kotlin.collections.MutableCollection", "remove", 1) to ::constFalse,
+        makeDescription("kotlin.collections.Map", "containsKey", 1) to ::constFalse,
+        makeDescription("kotlin.collections.Map", "containsValue", 1) to ::constFalse,
+        makeDescription("kotlin.collections.MutableMap", "remove", 2) to ::constFalse,
+        makeDescription("kotlin.collections.Map", "getOrDefault", 1) to ::getSecondArg,
+        makeDescription("kotlin.collections.Map", "get", 1) to ::constNull,
+        makeDescription("kotlin.collections.MutableMap", "remove", 1) to ::constNull,
+        makeDescription("kotlin.collections.List", "indexOf", 1) to ::constMinusOne,
+        makeDescription("kotlin.collections.List", "lastIndexOf", 1) to ::constMinusOne
+    )
+
+    fun findSpecialWithOverride(irFunction: IrSimpleFunction): Pair<IrSimpleFunction, (IrSimpleFunction) -> IrExpression>? {
+        irFunction.allOverridden().forEach { overridden ->
+            val description = overridden.toDescription()
+            SPECIAL_METHODS_WITH_DEFAULTS_MAP[description]?.let {
+                return Pair(overridden, it)
+            }
+        }
+        return null
+    }
+}
+
+fun IrSimpleFunction.allOverridden(): Sequence<IrSimpleFunction> {
+    val visited = mutableSetOf<IrSimpleFunction>()
+
+    fun IrSimpleFunction.search(): Sequence<IrSimpleFunction> {
+        if (this in visited) return emptySequence()
+        return sequence {
+            yield(this@search)
+            visited.add(this@search)
+            overriddenSymbols.forEach { yieldAll(it.owner.search()) }
+        }
+    }
+
+    return search().drop(1) // First element is `this`
+}