com.google.javascript.jscomp.GenerateExports Maven / Gradle / Ivy
/*
* Copyright 2008 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 static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.javascript.rhino.IR;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.jstype.JSType;
import com.google.javascript.rhino.jstype.JSTypeNative;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* Generates goog.exportSymbol/goog.exportProperty for the @export annotation.
*/
class GenerateExports implements CompilerPass {
private static final String PROTOTYPE_PROPERTY = "prototype";
private final AbstractCompiler compiler;
private final String exportSymbolFunction;
private final String exportPropertyFunction;
private final boolean allowNonGlobalExports;
private final Set exportedVariables = new HashSet<>();
/**
* Creates a new generate exports compiler pass.
*
* @param compiler JS compiler.
* @param exportSymbolFunction function used for exporting symbols.
* @param exportPropertyFunction function used for exporting property names.
*/
GenerateExports(
AbstractCompiler compiler,
boolean allowNonGlobalExports,
String exportSymbolFunction,
String exportPropertyFunction) {
checkNotNull(compiler);
checkNotNull(exportSymbolFunction);
checkNotNull(exportPropertyFunction);
this.compiler = compiler;
this.allowNonGlobalExports = allowNonGlobalExports;
this.exportSymbolFunction = exportSymbolFunction;
this.exportPropertyFunction = exportPropertyFunction;
}
Set getExportedVariableNames() {
return exportedVariables;
}
@Override
public void process(Node externs, Node root) {
FindExportableNodes findExportableNodes = new FindExportableNodes(
compiler, allowNonGlobalExports);
NodeTraversal.traverse(compiler, root, findExportableNodes);
Map exports = findExportableNodes.getExports();
Map es6Exports = findExportableNodes.getEs6ClassExports();
Set localExports = findExportableNodes.getLocalExports();
for (Map.Entry entry : es6Exports.entrySet()) {
addExportForEs6Method(entry.getKey(), entry.getValue());
}
for (Map.Entry entry : exports.entrySet()) {
String export = entry.getKey();
Node context = entry.getValue();
addExportMethod(exports, export, context);
}
for (String export : localExports) {
addExtern(export);
}
}
private void addExtern(String export) {
Node objectPrototype = NodeUtil.newQName(compiler, "Object.prototype");
JSType objCtor = compiler.getTypeRegistry().getNativeType(JSTypeNative.OBJECT_FUNCTION_TYPE);
objectPrototype.getFirstChild().setJSType(objCtor);
Node propstmt = IR.exprResult(IR.getprop(objectPrototype, IR.string(export)));
propstmt.useSourceInfoFromForTree(getSynthesizedExternsRoot());
propstmt.setOriginalName(export);
getSynthesizedExternsRoot().addChildToBack(propstmt);
compiler.reportChangeToEnclosingScope(propstmt);
}
private void recordExportSymbol(String qname) {
int dot = qname.indexOf('.');
if (dot == -1) {
exportedVariables.add(qname);
} else {
exportedVariables.add(qname.substring(0, dot));
}
}
private void addExportForEs6Method(Node memberFunction, String ownerName) {
// We always export ES6 member methods as properties.
checkArgument(memberFunction.isMemberFunctionDef(), memberFunction);
checkArgument(!ownerName.isEmpty(), ownerName);
String fullExport = ownerName + "." + memberFunction.getString();
addExportPropertyCall(ownerName, memberFunction, fullExport, memberFunction.getString());
}
/**
* Emits a call to either goog.exportProperty or goog.exportSymbol.
*
* Attempts to optimize by creating a property export instead of a symbol export, because
* property exports are significantly simpler/faster.
*
* @param export The fully qualified name of the object we want to export
* @param context The node on which the @export annotation was found
*/
private void addExportMethod(Map exports, String export, Node context) {
// We can export as a property if any of the following conditions holds:
// a) ES6 class members, which the above `addExportForEs6Method` handles
// b) this is a property on a name which is also being exported
// c) this is a prototype property
String methodOwnerName = null; // the object this method is on, null for exported names.
boolean isEs5StylePrototypeAssignment = false; // If this is a prototype property
String propertyName = null;
if (context.getFirstChild().isGetProp()) { // e.g. `/** @export */ a.prototype.b = obj;`
Node node = context.getFirstChild(); // e.g. get `a.prototype.b`
Node ownerNode = node.getFirstChild(); // e.g. get `a.prototype`
methodOwnerName = ownerNode.getQualifiedName(); // e.g. get the string "a.prototype"
if (ownerNode.isGetProp()
&& ownerNode.getLastChild().getString().equals(PROTOTYPE_PROPERTY)) {
// e.g. true if ownerNode is `a.prototype`
// false if this export were `/** @export */ a.b = obj;` instead
isEs5StylePrototypeAssignment = true;
}
propertyName = node.getSecondChild().getString();
}
boolean useExportSymbol = true;
if (isEs5StylePrototypeAssignment) {
useExportSymbol = false;
} else if (methodOwnerName != null && exports.containsKey(methodOwnerName)) {
useExportSymbol = false;
}
if (useExportSymbol) {
addExportSymbolCall(export, context);
} else {
addExportPropertyCall(methodOwnerName, context, export, propertyName);
}
}
private void addExportPropertyCall(
String methodOwnerName, Node context, String export, String propertyName) {
// exportProperty(object, publicName, symbol);
checkNotNull(methodOwnerName);
Node call =
IR.call(
NodeUtil.newQName(
compiler, exportPropertyFunction,
context, exportPropertyFunction),
NodeUtil.newQName(
compiler, methodOwnerName,
context, exportPropertyFunction),
IR.string(propertyName),
NodeUtil.newQName(
compiler, export,
context, exportPropertyFunction));
Node expression = IR.exprResult(call).useSourceInfoIfMissingFromForTree(context);
annotate(expression);
addStatement(context, expression);
}
private void addExportSymbolCall(String export, Node context) {
// exportSymbol(publicPath, object);
recordExportSymbol(export);
Node call =
IR.call(
NodeUtil.newQName(
compiler, exportSymbolFunction,
context, export),
IR.string(export),
NodeUtil.newQName(
compiler, export,
context, export));
Node expression = IR.exprResult(call).useSourceInfoIfMissingFromForTree(context);
annotate(expression);
addStatement(context, expression);
}
private void addStatement(Node context, Node stmt) {
CodingConvention convention = compiler.getCodingConvention();
Node n = context;
Node exprRoot = n;
while (!NodeUtil.isStatementBlock(exprRoot.getParent())) {
exprRoot = exprRoot.getParent();
}
// It's important that any class-building calls (goog.inherits)
// come right after the class definition, so move the export after that.
while (true) {
Node next = exprRoot.getNext();
if (next != null
&& NodeUtil.isExprCall(next)
&& convention.getClassesDefinedByCall(next.getFirstChild()) != null) {
exprRoot = next;
} else {
break;
}
}
Node block = exprRoot.getParent();
block.addChildAfter(stmt, exprRoot);
compiler.reportChangeToEnclosingScope(stmt);
}
private void annotate(Node node) {
NodeTraversal.traverse(
compiler, node, new PrepareAst.PrepareAnnotations());
}
/** Lazily create a "new" externs root for undeclared variables. */
private Node getSynthesizedExternsRoot() {
return compiler.getSynthesizedExternsInput().getAstRoot(compiler);
}
}