KT-12928: decompose invocation like "a.foo(b)" to "$t = a; $s = $t.foo.bind($t); $s(b)" instead of "$t = a.foo; $t(b)", since in the latter case foo won't receive proper this. Add optimization that replaces "foo.bar.bind(baz)(args)" with "baz.bar(args)"

js/js.inliner/src/org/jetbrains/kotlin/js/inline/ExpressionDecomposer.kt

@@ -20,6 +20,7 @@ import com.google.dart.compiler.backend.js.ast.*
 import com.google.dart.compiler.backend.js.ast.metadata.*
 import com.intellij.util.SmartList
 import org.jetbrains.kotlin.js.inline.util.IdentitySet
+import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils.*
 import org.jetbrains.kotlin.js.translate.utils.jsAstUtils.*
 
@@ -240,6 +241,7 @@ internal class ExpressionDecomposer private constructor(
 
     private abstract class Callable(hasArguments: HasArguments) {
         abstract var qualifier: JsExpression
+        abstract val applyBindIfNecessary: Boolean
         val arguments = hasArguments.arguments
     }
 
@@ -247,12 +249,14 @@ internal class ExpressionDecomposer private constructor(
         override var qualifier: JsExpression
             get() = invocation.qualifier
             set(value) { invocation.qualifier = value }
+        override val applyBindIfNecessary = true
     }
 
     private class CallableNewAdapter(val jsnew: JsNew) : Callable(jsnew) {
         override var qualifier: JsExpression
             get() = jsnew.constructorExpression
             set(value) { jsnew.constructorExpression = value }
+        override val applyBindIfNecessary = false
     }
 
     private fun Callable.process() {
@@ -267,13 +271,17 @@ internal class ExpressionDecomposer private constructor(
             // Qualifier might be a reference to lambda property. See KT-7674
             // An exception here is `fn.call()`, which are marked as side effect free. Further recognition of such
             // case in inliner might be quite difficult, so never extract such call (and other calls marked this way).
-             if ((qualifier !in containsNodeWithSideEffect || (qualifier as? HasMetadata)?.sideEffects == SideEffectKind.PURE) &&
-                 (callee != null && receiver != null && receiver in containsNodeWithSideEffect)
-             ) {
+            if ((qualifier as? HasMetadata)?.sideEffects == SideEffectKind.PURE &&
+                callee != null && receiver != null && receiver in containsNodeWithSideEffect
+            ) {
                 val receiverTmp = receiver.extractToTemporary()
                 callee.qualifier = receiverTmp
             }
             else {
+                if (receiver != null && callee != null && applyBindIfNecessary) {
+                    val receiverTmp = receiver.extractToTemporary()
+                    qualifier = JsAstUtils.invokeBind(receiverTmp, pureFqn(callee.ident, receiverTmp))
+                }
                 qualifier = qualifier.extractToTemporary()
             }
         }

js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/FunctionPostProcessor.kt

@@ -23,6 +23,7 @@ class FunctionPostProcessor(root: JsFunction) {
         { TemporaryAssignmentElimination(root.body).apply() },
         { RedundantLabelRemoval(root.body).apply() },
         { TemporaryVariableElimination(root).apply() },
+        { RedundantBindElimination(root.body).apply() },
         { IfStatementReduction(root.body).apply() },
         { DeadCodeElimination(root.body).apply() },
         { RedundantVariableDeclarationElimination(root.body).apply() },

js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/RedundantBindElimination.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2010-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.js.inline.clean
+
+import com.google.dart.compiler.backend.js.ast.JsBlock
+import com.google.dart.compiler.backend.js.ast.JsInvocation
+import com.google.dart.compiler.backend.js.ast.JsNameRef
+import com.google.dart.compiler.backend.js.ast.RecursiveJsVisitor
+
+// TODO: this optimization is a little unfair. It tries to recognize pattern like this a.bind(b)(args) and
+// replace it with b.a(args). However, we can't be completely sure that `a` is a Function.
+// Using JS-independent AST should solve the issue (as well as many other issues).
+class RedundantBindElimination(private val root: JsBlock) {
+    private var changed = false
+
+    fun apply(): Boolean {
+        root.accept(object : RecursiveJsVisitor() {
+            override fun visitInvocation(invocation: JsInvocation) {
+                tryEliminate(invocation)
+                super.visitInvocation(invocation)
+            }
+
+            private fun tryEliminate(invocation: JsInvocation) {
+                val qualifier = invocation.qualifier
+                if (qualifier !is JsInvocation) return
+
+                val outerQualifier = qualifier.qualifier
+                if (outerQualifier !is JsNameRef) return
+                val name = outerQualifier.name?.ident ?: outerQualifier.ident
+                if (name != "bind") return
+
+                val qualifierReplacement = outerQualifier.qualifier ?: return
+                invocation.qualifier = qualifierReplacement
+                changed = true
+            }
+        })
+
+        return changed
+    }
+}

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/InlineEvaluationOrderTestGenerated.java

@@ -221,6 +221,12 @@ public class InlineEvaluationOrderTestGenerated extends AbstractInlineEvaluation
         doTest(fileName);
     }
 
+    @TestMetadata("methodDecomposedWithBind.kt")
+    public void testMethodDecomposedWithBind() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineEvaluationOrder/cases/methodDecomposedWithBind.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("methodInlineCallQualifierWithSideEffect.kt")
     public void testMethodInlineCallQualifierWithSideEffect() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineEvaluationOrder/cases/methodInlineCallQualifierWithSideEffect.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/InlineMultiModuleTestGenerated.java

@@ -59,6 +59,18 @@ public class InlineMultiModuleTestGenerated extends AbstractInlineMultiModuleTes
         doTest(fileName);
     }
 
+    @TestMetadata("externalInlineCallDecomposed")
+    public void testExternalInlineCallDecomposed() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineMultiModule/cases/externalInlineCallDecomposed/");
+        doTest(fileName);
+    }
+
+    @TestMetadata("externalInlineNewDecomposed")
+    public void testExternalInlineNewDecomposed() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineMultiModule/cases/externalInlineNewDecomposed/");
+        doTest(fileName);
+    }
+
     @TestMetadata("lambda")
     public void testLambda() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineMultiModule/cases/lambda/");

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/JsAstUtils.java

@@ -490,6 +490,11 @@ public final class JsAstUtils {
         return result;
     }
 
+    @NotNull
+    public static JsInvocation invokeBind(@NotNull JsExpression receiver, @NotNull JsExpression method) {
+        return invokeMethod(method, "bind", receiver);
+    }
+
     public static boolean isUndefinedExpression(JsExpression expression) {
         if (!(expression instanceof JsUnaryOperation)) return false;
 

js/js.translator/testData/inlineEvaluationOrder/cases/methodDecomposedWithBind.kt

@@ -0,0 +1,8 @@
+package foo
+
+fun box(): String {
+    val v = mapOf(1 to "1", 2 to "2").mapValues { it.value.map { it.toString() } }
+    assertEquals(2, v.size)
+
+    return "OK"
+}

js/js.translator/testData/inlineMultiModule/cases/externalInlineCallDecomposed/lib/lib.kt

@@ -0,0 +1,9 @@
+package lib
+
+var global = ""
+
+inline fun baz(x: () -> Int) = A(1).bar(x())
+
+class A(val y: Int) {
+    fun bar(x: Int) = x + y
+}

js/js.translator/testData/inlineMultiModule/cases/externalInlineCallDecomposed/main/main.kt

@@ -0,0 +1,20 @@
+package foo
+
+import lib.*
+
+fun qqq(): Int {
+    global += "qqq;"
+    return 23
+}
+
+fun box(): String {
+    assertEquals(24, baz {
+        global += "before;"
+        val result = qqq()
+        global += "after;"
+        result
+    })
+    assertEquals("before;qqq;after;", global)
+
+    return "OK"
+}

js/js.translator/testData/inlineMultiModule/cases/externalInlineNewDecomposed/lib/lib.kt

@@ -0,0 +1,11 @@
+package lib
+
+var global = ""
+
+inline fun baz(x: () -> Int) = ((A(1).B(x()) as Any) as A.B).bar()
+
+class A(val y: Int) {
+    inner class B(val x: Int) {
+        fun bar() = x + y
+    }
+}

js/js.translator/testData/inlineMultiModule/cases/externalInlineNewDecomposed/main/main.kt

@@ -0,0 +1,20 @@
+package foo
+
+import lib.*
+
+fun qqq(): Int {
+    global += "qqq;"
+    return 23
+}
+
+fun box(): String {
+    assertEquals(24, baz {
+        global += "before;"
+        val result = qqq()
+        global += "after;"
+        result
+    })
+    assertEquals("before;qqq;after;", global)
+
+    return "OK"
+}