[JS IR DCE] Add CLI option to print reachability info

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSCompilerArguments.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2015 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.
+ * Copyright 2010-2020 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.cli.common.arguments
@@ -133,6 +122,9 @@ class K2JSCompilerArguments : CommonCompilerArguments() {
     @Argument(value = "-Xir-dce-driven", description = "Perform a more experimental faster dead code elimination")
     var irDceDriven: Boolean by FreezableVar(false)
 
+    @Argument(value = "-Xir-dce-print-reachability-info", description = "Print declarations' reachability info to stdout during performing DCE")
+    var irDcePrintReachabilityInfo: Boolean by FreezableVar(false)
+
     @Argument(value = "-Xir-only", description = "Disables pre-IR backend")
     var irOnly: Boolean by FreezableVar(false)
 

compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/K2JsIrCompiler.kt

@@ -1,6 +1,6 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
- * that can be found in the license/LICENSE.txt file.
+ * Copyright 2010-2020 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.cli.js
@@ -317,6 +317,8 @@ class K2JsIrCompiler : CLICompiler<K2JSCompilerArguments>() {
         if (!arguments.sourceMap && sourceMapEmbedContentString != null) {
             messageCollector.report(WARNING, "source-map-embed-sources argument has no effect without source map", null)
         }
+
+        configuration.put(JSConfigurationKeys.PRINT_REACHABILITY_INFO, arguments.irDcePrintReachabilityInfo)
     }
 
     override fun executableScriptFileName(): String {

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/Dce.kt

@@ -19,10 +19,9 @@ import org.jetbrains.kotlin.ir.util.*
 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.js.config.JSConfigurationKeys
 import java.util.*
 
-private val PRINT_REACHABILITY_INFO = java.lang.Boolean.getBoolean("kotlin.js.ir.dce.print.reachability.info")
-
 fun eliminateDeadDeclarations(
     module: IrModuleFragment,
     context: JsIrBackendContext,
@@ -99,7 +98,10 @@ private fun removeUselessDeclarations(module: IrModuleFragment, usefulDeclaratio
 }
 
 fun usefulDeclarations(roots: Iterable<IrDeclaration>, context: JsIrBackendContext): Set<IrDeclaration> {
-    val reachabilityInfo: MutableSet<String> = if (PRINT_REACHABILITY_INFO) linkedSetOf() else Collections.emptySet()
+    val printReachabilityInfo =
+        context.configuration.getBoolean(JSConfigurationKeys.PRINT_REACHABILITY_INFO) ||
+                java.lang.Boolean.getBoolean("kotlin.js.ir.dce.print.reachability.info")
+    val reachabilityInfo: MutableSet<String> = if (printReachabilityInfo) linkedSetOf() else Collections.emptySet()
 
     val queue = ArrayDeque<IrDeclaration>()
     val result = hashSetOf<IrDeclaration>()
@@ -116,7 +118,7 @@ fun usefulDeclarations(roots: Iterable<IrDeclaration>, context: JsIrBackendConte
             return
         }
 
-        if (PRINT_REACHABILITY_INFO) {
+        if (printReachabilityInfo) {
             val fromFqn = (from as? IrDeclarationWithName)?.fqNameWhenAvailable?.asString() ?: altFromFqn ?: "<unknown>"
 
             val toFqn = (this as? IrDeclarationWithName)?.fqNameWhenAvailable?.asString() ?: "<unknown>"
@@ -342,7 +344,7 @@ fun usefulDeclarations(roots: Iterable<IrDeclaration>, context: JsIrBackendConte
         }
     }
 
-    if (PRINT_REACHABILITY_INFO) {
+    if (printReachabilityInfo) {
         reachabilityInfo.forEach(::println)
     }
 

compiler/testData/cli/js/jsExtraHelp.out

@@ -7,6 +7,8 @@ where advanced options include:
   -Xinclude=<path>           A path to an intermediate library that should be processed in the same manner as source files.
   -Xir-dce                   Perform experimental dead code elimination
   -Xir-dce-driven            Perform a more experimental faster dead code elimination
+  -Xir-dce-print-reachability-info
+                             Print declarations' reachability info to stdout during performing DCE
   -Xir-only                  Disables pre-IR backend
   -Xir-produce-js            Generates JS file using IR backend. Also disables pre-IR backend
   -Xir-produce-klib-dir      Generate unpacked KLIB into parent directory of output JS file.

js/js.frontend/src/org/jetbrains/kotlin/js/config/JSConfigurationKeys.java

@@ -1,17 +1,6 @@
 /*
- * 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.
+ * Copyright 2010-2020 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.js.config;
@@ -91,4 +80,7 @@ public class JSConfigurationKeys {
     public static final CompilerConfigurationKey<Map<String, String>> FILE_PATHS_PREFIX_MAP =
             CompilerConfigurationKey.create("this map used to shorten/replace prefix of paths in comments with file paths, " +
                                             "including region comments");
+
+    public static final CompilerConfigurationKey<Boolean> PRINT_REACHABILITY_INFO =
+            CompilerConfigurationKey.create("print declarations' reachability info during performing DCE");
 }