com.google.javascript.jscomp.J2clPass Maven / Gradle / Ivy
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/*
* Copyright 2015 The Closure Compiler Authors.
*
* 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 com.google.javascript.jscomp;
import com.google.common.base.Supplier;
import com.google.common.collect.ImmutableSet;
import com.google.javascript.jscomp.FunctionInjector.InliningMode;
import com.google.javascript.jscomp.FunctionInjector.Reference;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.rhino.Node;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/** A normalization pass to inline some J2CL calls to enable other optimizations. */
public class J2clPass implements CompilerPass {
private static final String ALL_CLASS_FILE_NAMES = "*";
private final AbstractCompiler compiler;
private final Supplier safeNameIdSupplier;
public J2clPass(AbstractCompiler compiler) {
this.compiler = compiler;
this.safeNameIdSupplier = compiler.getUniqueNameIdSupplier();
}
@Override
public void process(Node externs, Node root) {
if (!J2clSourceFileChecker.shouldRunJ2clPasses(compiler)) {
return;
}
/*
* Inlines Arrays.$create(), Arrays.$init(), Arrays.$instanceIsOfType(), Arrays.$castTo() and
* Casts.$to() so that all references to $isInstance() functions will be fully qualified to work
* with collapse properties.
*/
inlineFunctionsInFile(
root,
"Arrays.impl.java.js",
ImmutableSet.of("$create", "$init", "$instanceIsOfType", "$castTo", "$stampType"),
InliningMode.DIRECT);
inlineFunctionsInFile(root, "Casts.impl.java.js", ImmutableSet.of("$to"), InliningMode.DIRECT);
/*
* Inlines all Interface.$markImplementor(FooClass) metaclass calls so that FooClass and others
* like it are not unnecessarily retained and so that static analysis of interface instanceof
* calls becomes possible.
*
* Note that this pass should NOT be restricted to j2cl .java.js files because JavaScript code
* implementing Java interfaces (not recommended but widely used in xplat) needs calls to
* $markImplementor.
*/
inlineFunctionsInFile(
root, ALL_CLASS_FILE_NAMES, ImmutableSet.of("$markImplementor"), InliningMode.BLOCK);
/*
* Inlines class metadata calls so they become optimizable and avoids escaping of constructor.
*/
inlineFunctionsInFile(
root,
"Util.impl.java.js",
ImmutableSet.of(
"$setClassMetadata",
"$setClassMetadataForInterface",
"$setClassMetadataForEnum",
"$setClassMetadataForPrimitive"),
InliningMode.BLOCK);
}
private void inlineFunctionsInFile(
Node root, String classFileName, Set fnNamesToInline, InliningMode inliningMode) {
new ClassStaticFunctionsInliner(root, classFileName, fnNamesToInline, inliningMode).run();
}
/**
* Collects references to certain function definitions in a certain class and then inlines fully
* qualified static method calls to those functions anywhere in the program.
*
* Assumes that the set of provided short function names will not collide with any of the
* collected fully qualified function names once the module prefix has been added.
*/
private class ClassStaticFunctionsInliner {
private final String classFileName;
private final Set fnNamesToInline;
private final InliningMode inliningMode;
private final Map fnsToInlineByQualifiedName = new HashMap<>();
private final FunctionInjector injector;
private final Node root;
private ClassStaticFunctionsInliner(
Node root, String classFileName, Set fnNamesToInline, InliningMode inliningMode) {
this.root = root;
this.classFileName = classFileName;
this.fnNamesToInline = fnNamesToInline;
this.inliningMode = inliningMode;
this.injector =
new FunctionInjector.Builder(compiler)
.safeNameIdSupplier(safeNameIdSupplier)
.assumeStrictThis(true)
.assumeMinimumCapture(true)
.build();
this.injector.setKnownConstantFunctions(ImmutableSet.copyOf(fnNamesToInline));
}
private void run() {
NodeTraversal.traverse(compiler, root, new FunctionDefsCollector());
NodeTraversal.traverse(compiler, root, new StaticCallInliner());
}
private class FunctionDefsCollector implements NodeTraversal.Callback {
@Override
public boolean shouldTraverse(NodeTraversal nodeTraversal, Node n, Node parent) {
// Only look inside the referenced class file.
return !n.isScript()
|| n.getSourceFileName().endsWith(classFileName)
|| classFileName.equals(ALL_CLASS_FILE_NAMES);
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// If we arrive here then we're already inside the desired script.
// Only look at named function declarations that are fully qualified.
final String qualifiedFnName;
final String fnName;
switch (n.getToken()) {
case ASSIGN:
// TODO(b/69730966): Delete this branch when ES5 syntax support is no longer needed.
if (!n.getLastChild().isFunction()) {
return;
}
Node qualifiedNameNode = n.getFirstChild();
if (!qualifiedNameNode.isGetProp() || !qualifiedNameNode.isQualifiedName()) {
return;
}
qualifiedFnName = qualifiedNameNode.getQualifiedName();
fnName = qualifiedNameNode.getString();
break;
case MEMBER_FUNCTION_DEF:
qualifiedFnName = NodeUtil.getBestLValueName(n);
fnName = n.getString();
break;
default:
return;
}
if (fnNamesToInline.contains(fnName)) {
// Then store a reference to it.
fnsToInlineByQualifiedName.put(qualifiedFnName, n.getLastChild());
}
}
}
private class StaticCallInliner extends AbstractPostOrderCallback {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// Only look at method calls
if (!n.isCall()) {
return;
}
// ... that are fully qualified
Node qualifiedNameNode = n.getFirstChild();
if (!qualifiedNameNode.isGetProp() || !qualifiedNameNode.isQualifiedName()) {
return;
}
// ... and that reference a function definition we want to inline
String qualifiedFnName = qualifiedNameNode.getQualifiedName();
String fnName = qualifiedNameNode.getString();
Node fnImpl = fnsToInlineByQualifiedName.get(qualifiedFnName);
if (fnImpl == null) {
return;
}
// Ensure that the function only has a single return statement when direct inlining.
if (inliningMode == InliningMode.DIRECT
&& !NodeUtil.getFunctionBody(fnImpl).getFirstChild().isReturn()) {
throw new IllegalStateException(
"Attempted to direct inline function "
+ qualifiedFnName
+ ", but function is not a simple return.");
}
// Otherwise inline the call.
// Note: This pass has to run before normalization, so we must use the unsafeInline method.
// It is safe because these are strictly controlled trivial bootstrap methods that are
// written with inlining in mind (e.g. doesn't read/write local/global variables).
// TODO(goktug): Add a check that will ensure safety of this.
Node inlinedCall =
injector.unsafeInline(
new Reference(n, t.getScope(), t.getChunk(), inliningMode), fnName, fnImpl);
// Avoid overridding original source information with the helper classes source information.
// For example; we want a cast to point related Java statement instead of the Casts utility.
inlinedCall.srcrefTree(n);
t.getCompiler().reportChangeToEnclosingScope(inlinedCall);
}
}
}
}