wasm gc: preprocess JS runtime with closure compiler

core/build.gradle.kts

@@ -21,7 +21,13 @@ plugins {
 
 description = "Compiler, backends and runtime"
 
+configurations {
+    register("closureCompiler")
+}
+
 dependencies {
+    "closureCompiler"(libs.google.closure.compiler)
+
     api(project(":interop:core"))
     api(project(":metaprogramming:api"))
 
@@ -35,6 +41,38 @@ dependencies {
     testImplementation(libs.junit)
 }
 
+val jsGenerateDir = layout.buildDirectory.dir("generated/js/raw")
+val jsOutputDir = layout.buildDirectory.dir("generated/js/optimized")
+val jsInputDir = layout.projectDirectory.dir("src/main/js/wasm-gc-runtime")
+val jsInput = jsInputDir.file("runtime.js")
+
+val simpleRuntime = tasks.register("generateSimpleRuntime") {
+    val outputFile = jsGenerateDir.map { it.file("wasm-gc-runtime.js") }
+    val wrapperFile = jsInputDir.file("simple-wrapper.js")
+    inputs.file(wrapperFile)
+    outputs.file(outputFile)
+    doFirst {
+        val wrapper = wrapperFile.asFile.readText()
+        val runtime = jsInput.asFile.readText()
+        outputFile.get().asFile.writeText(wrapper.replace("include();", runtime))
+    }
+}
+
+tasks.register<JavaExec>("optimizeSimpleRuntime") {
+    val inputFiles = simpleRuntime.map { it.outputs.files }
+    classpath(configurations["closureCompiler"])
+    inputs.file(inputFiles)
+    mainClass = "com.google.javascript.jscomp.CommandLineRunner"
+
+    args(Iterable {
+        listOf(
+            "--compilation_level=SIMPLE_OPTIMIZATIONS",
+            "--js_output_file=" + jsOutputDir.get().asFile.absolutePath + "/wasm-gc-runtime.js",
+            inputFiles.get().singleFile.absolutePath
+        ).iterator()
+    })
+}
+
 teavmPublish {
     artifactId = "teavm-core"
 }

core/src/main/js/wasm-gc-runtime/module-wrapper.js

@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  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.
+ */
+
+include();
+export { load, defaults };