JS inline: common reference utilities for cleaning up after inline

js/js.inliner/src/org/jetbrains/k2js/inline/clean/GenericRemover.kt

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+/*
+ * Copyright 2010-2014 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.k2js.inline.clean
+
+import com.google.dart.compiler.backend.js.ast.*
+
+private class GenericRemover<T : JsNode>(removable: Collection<T> = listOf()) : NodeRemovingVisitor<T>(removable) {
+
+    override fun <T : JsNode?> doTraverse(node: T?, ctx: JsContext?) {
+        if (node == null) return
+
+        if (shouldRemove(node)) {
+            ctx?.removeMe()
+        } else {
+            super.doTraverse(node, ctx)
+        }
+    }
+}

js/js.inliner/src/org/jetbrains/k2js/inline/clean/NodeRemovingVisitor.kt

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+/*
+ * Copyright 2010-2014 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.k2js.inline.clean
+
+import com.google.dart.compiler.backend.js.ast.*
+import org.jetbrains.k2js.inline.util.IdentitySet
+
+import java.util.IdentityHashMap
+import org.jetbrains.k2js.inline.util.toIdentitySet
+
+private abstract class NodeRemovingVisitor<T : JsNode>(removable: Collection<T>) : JsVisitorWithContextImpl() {
+    private val removeSet: Set<T> = removable.toIdentitySet()
+
+    protected fun <R : JsNode?> shouldRemove(node: R): Boolean {
+        return removeSet.contains(node)
+    }
+}

js/js.inliner/src/org/jetbrains/k2js/inline/clean/ReferenceTracker.kt

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+/*
+ * Copyright 2010-2014 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.k2js.inline.clean
+
+import com.google.dart.compiler.backend.js.ast.*
+import org.jetbrains.k2js.inline.util.IdentitySet
+
+import java.util.IdentityHashMap
+import java.util.ArrayList
+
+private class ReferenceTracker<Reference, RemoveCandidate : JsNode> {
+    private val reachable = IdentityHashMap<Reference, Boolean>()
+    private val removableCandidates = IdentityHashMap<Reference, RemoveCandidate>()
+    private val refereceFromTo = IdentityHashMap<Reference, MutableList<Reference>>()
+    private val visited = IdentitySet<Reference>()
+
+    public val removable: List<RemoveCandidate>
+        get() {
+            return reachable
+                        .filter { !it.value }
+                        .map { removableCandidates.get(it.key)!! }
+        }
+
+    public fun addCandidateForRemoval(reference: Reference, candidate: RemoveCandidate) {
+        assert(!isKnown(reference)) { "Candidate for removal cannot be reassigned: $candidate" }
+
+        removableCandidates.put(reference, candidate)
+        reachable.put(reference, false)
+    }
+
+    public fun addRemovableReference(referer: Reference, referenced: Reference) {
+        if (!isKnown(referenced)) return
+
+        getReferencedBy(referer).add(referenced)
+
+        if (isReachable(referer)) {
+            markReachable(referenced)
+        }
+    }
+
+    public fun markReachable(reference: Reference) {
+        if (!isKnown(reference)) return
+
+        visited.add(reference)
+        getReferencedBy(reference)
+                .filterNot { it in visited }
+                .filter { isKnown(it) && !isReachable(it) }
+                .forEach { markReachable(it) }
+
+        visited.remove(reference)
+        reachable[reference] = true
+    }
+
+    private fun getReferencedBy(referer: Reference): MutableList<Reference> {
+        return refereceFromTo.getOrPut(referer, { ArrayList<Reference>() })
+    }
+
+    private fun isKnown(ref: Reference): Boolean {
+        return removableCandidates.containsKey(ref)
+    }
+
+    private fun isReachable(ref: Reference): Boolean {
+        return reachable[ref] ?: false
+    }
+}

js/js.inliner/src/org/jetbrains/k2js/inline/clean/referenceCollectionUtils.kt

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+/*
+ * Copyright 2010-2014 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.k2js.inline.clean
+
+import com.google.dart.compiler.backend.js.ast.*
+import org.jetbrains.k2js.inline.util.IdentitySet
+
+import java.util.ArrayList
+
+private fun collectFunctionReferencesInside(scope: JsNode): List<JsName> {
+    return with(ReferenceNameCollector()) {
+        accept(scope)
+        references.filter { it.getStaticRef() is JsFunction }
+    }
+}
+
+private fun collectReferencesInside(scope: JsNode): List<JsName> {
+    return with(ReferenceNameCollector()) {
+        accept(scope)
+        references
+    }
+}
+
+private class ReferenceNameCollector : JsVisitorWithContextImpl() {
+    private val referenceSet = IdentitySet<JsName>()
+
+    public val references: List<JsName>
+        get() = referenceSet.toList()
+
+    override fun endVisit(x: JsNameRef?, ctx: JsContext?) {
+        val name = x?.getName()
+        if (name != null) {
+            referenceSet.add(name)
+        }
+    }
+}