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/*
* 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.common.annotations.VisibleForTesting;
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;
import org.jspecify.nullness.Nullable;
/** Generates goog.exportSymbol/goog.exportProperty for the @export annotation. */
public class GenerateExports implements CompilerPass {
private static final String PROTOTYPE_PROPERTY = "prototype";
private final AbstractCompiler compiler;
private final @Nullable String exportSymbolFunction;
private final @Nullable String exportPropertyFunction;
private final boolean allowNonGlobalExports;
private final Set exportedVariables = new HashSet<>();
static final DiagnosticType MISSING_EXPORT_CONVENTION =
DiagnosticType.error(
"JSC_MISSING_EXPORT_CONVENTION",
"@export cannot be used without defining a exportProperty and exportSymbol function in"
+ " the coding convention");
@VisibleForTesting
public static final DiagnosticType MISSING_GOOG_FOR_EXPORT =
DiagnosticType.error(
"JSC_MISSING_EXPORT_SYMBOL_DEFINITION",
"@export cannot be used without including closure/base.js or other definition of"
+ " {0} and {1}");
/**
* Creates a new generate exports compiler pass.
*
* The {@code exportSymbolFunction} and {@code exportPropertyFunction} are optional, but the
* compiler will report an error if they are not passed and this pass finds @export
* annotations. They are allowed to be optional if no code uses the @export annotation.
*
* @param compiler JS compiler.
* @param exportSymbolFunction function used for exporting symbols.
* @param exportPropertyFunction function used for exporting property names.
*/
GenerateExports(
AbstractCompiler compiler,
boolean allowNonGlobalExports,
@Nullable String exportSymbolFunction,
@Nullable String exportPropertyFunction) {
checkNotNull(compiler);
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 (String export : localExports) {
addExtern(export);
}
if (!exports.isEmpty() || !es6Exports.isEmpty()) {
if (!validateExportMethodsIncluded(exports, es6Exports, root)) {
return;
}
}
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);
}
}
/**
* Validate that a) the user has configured methods to call to export symbols and b) those methods
* are included in this binary
*
* @return whether to continue trying to export methods
*/
private boolean validateExportMethodsIncluded(
Map exports, Map es6Exports, Node root) {
// Pick an arbitrary @export to report the warning on.
final Node errorLocation;
if (!exports.isEmpty()) {
errorLocation = exports.values().stream().findFirst().get();
} else {
errorLocation = es6Exports.keySet().stream().findFirst().get();
}
if (this.exportSymbolFunction == null || this.exportPropertyFunction == null) {
compiler.report(JSError.make(errorLocation, MISSING_EXPORT_CONVENTION));
// don't try to rewrite @export since there's nothing we can rewrite them to.
return false;
}
if (!includesExportMethods(root.getParent())) {
compiler.report(
JSError.make(
errorLocation,
MISSING_GOOG_FOR_EXPORT,
this.exportSymbolFunction,
this.exportPropertyFunction));
declareExportMethodsInExterns(errorLocation);
return true;
}
return true;
}
/**
* In order to use @export, the user must have included the defintiion of the property and symbol
* export methods in their binary.
*
* In real code these methods are typically goog.exportProperty and goog.exportSymbol.
*/
private boolean includesExportMethods(Node root) {
Scope globalScope = new SyntacticScopeCreator(compiler).createScope(root, /* parent= */ null);
String exportPropertyRoot = NodeUtil.getRootOfQualifiedName(exportPropertyFunction);
String exportSymbolRoot = NodeUtil.getRootOfQualifiedName(exportSymbolFunction);
return globalScope.hasSlot(exportPropertyRoot) && globalScope.hasSlot(exportSymbolRoot);
}
/** Add a synthesized externs declaration to prevent crashes later on in VarCheck. */
private void declareExportMethodsInExterns(Node srcref) {
String exportPropertyRoot = NodeUtil.getRootOfQualifiedName(exportPropertyFunction);
String exportSymbolRoot = NodeUtil.getRootOfQualifiedName(exportSymbolFunction);
if (exportPropertyRoot.equals(exportSymbolRoot)) {
declareSyntheticExternsVar(exportPropertyRoot, srcref);
} else {
declareSyntheticExternsVar(exportPropertyRoot, srcref);
declareSyntheticExternsVar(exportSymbolRoot, srcref);
}
}
private void declareSyntheticExternsVar(String name, Node srcref) {
CompilerInput syntheticInput = compiler.getSynthesizedExternsInput();
Node syntheticVarRoot = syntheticInput.getAstRoot(compiler);
Node varDeclaration = IR.var(IR.name(name)).srcrefTree(srcref);
varDeclaration.setStaticSourceFile(compiler.getSynthesizedExternsInput().getSourceFile());
syntheticVarRoot.addChildToBack(varDeclaration);
compiler.reportChangeToEnclosingScope(varDeclaration);
}
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, export));
propstmt.srcrefTree(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.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.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).srcrefTreeIfMissing(context);
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).srcrefTreeIfMissing(context);
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;
}
}
stmt.insertAfter(exprRoot);
compiler.reportChangeToEnclosingScope(stmt);
}
/** Lazily create a "new" externs root for undeclared variables. */
private Node getSynthesizedExternsRoot() {
return compiler.getSynthesizedExternsInput().getAstRoot(compiler);
}
}