com.google.javascript.jscomp.SymbolTable Maven / Gradle / Ivy
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/*
* Copyright 2011 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.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicates;
import com.google.common.collect.HashBasedTable;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Ordering;
import com.google.common.collect.Table;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.jscomp.base.format.SimpleFormat;
import com.google.javascript.jscomp.modules.Module;
import com.google.javascript.jscomp.modules.ModuleMetadataMap.ModuleType;
import com.google.javascript.rhino.JSDocInfo;
import com.google.javascript.rhino.JSDocInfo.Marker;
import com.google.javascript.rhino.JSDocInfo.Visibility;
import com.google.javascript.rhino.JSTypeExpression;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.SourcePosition;
import com.google.javascript.rhino.StaticRef;
import com.google.javascript.rhino.StaticScope;
import com.google.javascript.rhino.StaticSlot;
import com.google.javascript.rhino.StaticSourceFile;
import com.google.javascript.rhino.StaticSymbolTable;
import com.google.javascript.rhino.jstype.EnumType;
import com.google.javascript.rhino.jstype.FunctionType;
import com.google.javascript.rhino.jstype.JSType;
import com.google.javascript.rhino.jstype.JSTypeNative;
import com.google.javascript.rhino.jstype.JSTypeRegistry;
import com.google.javascript.rhino.jstype.ObjectType;
import com.google.javascript.rhino.jstype.SimpleReference;
import com.google.javascript.rhino.jstype.SimpleSlot;
import com.google.javascript.rhino.jstype.StaticTypedScope;
import com.google.javascript.rhino.jstype.StaticTypedSlot;
import com.google.javascript.rhino.jstype.UnionType;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.TreeSet;
import java.util.function.Predicate;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jspecify.nullness.Nullable;
/**
* A symbol table for people that want to use Closure Compiler as an indexer.
*
* Contains an index of all the symbols in the code within a compilation job. The API is designed
* for people who want to visit all the symbols, rather than people who want to lookup a specific
* symbol by a certain key.
*
*
We can use this to combine different types of symbol tables. For example, one class might have
* a {@code StaticSymbolTable} of all variable references, and another class might have a {@code
* StaticSymbolTable} of all type names in JSDoc comments. This class allows you to combine them
* into a unified index.
*
*
Most passes build their own "partial" symbol table that implements the same interface
* (StaticSymbolTable, StaticSlot, and friends). Individual compiler passes usually need more or
* less metadata about the certainty of symbol information. Building a complete symbol table with
* all the necessary metadata for all passes would be too slow. However, as long as these "partial"
* symbol tables implement the proper interfaces, we should be able to add them to this symbol table
* to make it more complete.
*
*
If clients want fast lookup, they should build their own wrapper around this symbol table that
* indexes symbols or references by the desired lookup key.
*
*
By design, when this symbol table creates symbols for types, it tries to mimic the symbol
* table you would get in an OO language. For example, the "type Foo" and "the constructor that
* creates objects of type Foo" are the same symbol. The types of "Foo.prototype" and "new Foo()"
* also have the same symbol. Although JSCompiler internally treats these as distinct symbols, we
* assume that most clients will not care about the distinction.
*
* @see #addSymbolsFrom For more information on how to write plugins for this symbol table.
*/
public final class SymbolTable {
private static final Logger logger = Logger.getLogger(SymbolTable.class.getName());
/**
* The name we use for the JavaScript built-in Global object. It's anonymous in JavaScript, so we
* have to give it an invalid identifier to avoid conflicts with user-defined property names.
*/
public static final String GLOBAL_THIS = "*global*";
/**
* All symbols in the program, uniquely identified by the node where they're declared and their
* name.
*/
private final Table symbols = HashBasedTable.create();
/**
* All syntactic scopes in the program, uniquely identified by the node where they're declared.
*/
private final Map scopes = new LinkedHashMap<>();
/** All Nodes with JSDocInfo in the program. */
private final List docInfos = new ArrayList<>();
private @Nullable SymbolScope globalScope = null;
private final AbstractCompiler compiler;
private final JSTypeRegistry registry;
/** Clients should get a symbol table by asking the compiler at the end of a compilation job. */
SymbolTable(AbstractCompiler compiler, JSTypeRegistry registry) {
this.compiler = compiler;
this.registry = registry;
}
public Iterable getReferences(Symbol symbol) {
return Collections.unmodifiableCollection(symbol.references.values());
}
public ImmutableList getReferenceList(Symbol symbol) {
return ImmutableList.copyOf(symbol.references.values());
}
public ImmutableList getAllSymbols() {
return ImmutableList.copyOf(symbols.values());
}
/** Get the symbols in their natural ordering. Always returns a mutable list. */
public List getAllSymbolsSorted() {
return getNaturalSymbolOrdering().sortedCopy(symbols.values());
}
/**
* Gets the 'natural' ordering of symbols.
*
* Right now, we only guarantee that symbols in the global scope will come before symbols in
* local scopes. After that, the order is deterministic but undefined.
*/
public Ordering getNaturalSymbolOrdering() {
return symbolOrdering;
}
public SymbolScope getScope(Symbol slot) {
return slot.scope;
}
public Collection getAllJSDocInfoNodes() {
return Collections.unmodifiableList(docInfos);
}
/**
* Gets the scope that contains the given node. If {@code n} is a function name, we return the
* scope that contains the function, not the function itself.
*/
public @Nullable SymbolScope getEnclosingScope(Node n) {
Node current = n.getParent();
if (n.isName() && n.getParent().isFunction()) {
current = current.getParent();
}
for (; current != null; current = current.getParent()) {
if (scopes.containsKey(current)) {
return scopes.get(current);
}
}
return null;
}
/**
* Gets the scope that contains the given node. If {@code n} is a function name, we return the
* scope that contains the function, not the function itself. The returned scope is either
* function or global scope.
*/
public SymbolScope getEnclosingFunctionScope(Node n) {
Node current = n.getParent();
if (n.isName() && current != null && current.isFunction()) {
current = current.getParent();
}
for (; current != null; current = current.getParent()) {
SymbolScope scope = scopes.get(current);
if (scope != null && !scope.isBlockScope()) {
return scope;
}
}
return globalScope;
}
/**
* If {@code sym} is a function, try to find a Symbol for a parameter with the given name.
*
* Returns null if we couldn't find one.
*
*
Notice that this just makes a best effort, and may not be able to find parameters for
* non-conventional function definitions. For example, we would not be able to find "y" in this
* code:
* var x = x() ? function(y) {} : function(y) {};
*
*/
public @Nullable Symbol getParameterInFunction(Symbol sym, String paramName) {
SymbolScope scope = getScopeInFunction(sym);
if (scope != null) {
Symbol param = scope.getSlot(paramName);
if (param != null && param.scope == scope) {
return param;
}
}
return null;
}
private @Nullable SymbolScope getScopeInFunction(Symbol sym) {
FunctionType type = sym.getFunctionType();
if (type == null) {
return null;
}
Node functionNode = type.getSource();
if (functionNode == null) {
return null;
}
return scopes.get(functionNode);
}
/**
* All local scopes are associated with a function, and some functions are associated with a
* symbol. Returns the symbol associated with the given scope.
*/
public Symbol getSymbolForScope(SymbolScope scope) {
if (scope.getSymbolForScope() == null) {
scope.setSymbolForScope(findSymbolForScope(scope));
}
return scope.getSymbolForScope();
}
/**
* Find the symbol associated with the given scope. Notice that we won't always be able to figure
* out this association dynamically, so sometimes we'll just create the association when we create
* the scope.
*/
private @Nullable Symbol findSymbolForScope(SymbolScope scope) {
Node rootNode = scope.getRootNode();
if (rootNode.getParent() == null) {
return globalScope.getSlot(GLOBAL_THIS);
}
if (!rootNode.isFunction()) {
return null;
}
String name = NodeUtil.getBestLValueName(NodeUtil.getBestLValue(rootNode));
return name == null ? null : scope.getParentScope().getQualifiedSlot(name);
}
/**
* Get all symbols associated with the type of the given symbol.
*
*
For example, given a variable x declared as /* @type {Array|Date} / var x = f(); this will
* return the constructors for Array and Date.
*/
public Iterable getAllSymbolsForTypeOf(Symbol sym) {
return getAllSymbolsForType(getType(sym));
}
/** Returns the global scope. */
public SymbolScope getGlobalScope() {
return globalScope;
}
/** Gets the symbol for the given constructor or interface. */
public Symbol getSymbolDeclaredBy(FunctionType fn) {
checkState(fn.isConstructor() || fn.isInterface());
ObjectType instanceType = fn.getInstanceType();
return getSymbolForName(fn.getSource(), instanceType.getReferenceName());
}
/** Gets the symbol for the given enum. */
public Symbol getSymbolDeclaredBy(EnumType enumType) {
return getSymbolForName(enumType.getSource(), enumType.getElementsType().getReferenceName());
}
/** Gets the symbol for the prototype if this is the symbol for a constructor or interface. */
public @Nullable Symbol getSymbolForInstancesOf(Symbol sym) {
FunctionType fn = sym.getFunctionType();
if (fn != null && fn.isNominalConstructorOrInterface()) {
return getSymbolForInstancesOf(fn);
}
return null;
}
/** Gets the symbol for the prototype of the given constructor or interface. */
public Symbol getSymbolForInstancesOf(FunctionType fn) {
checkState(fn.isConstructor() || fn.isInterface());
ObjectType pType = fn.getPrototype();
return getSymbolForName(fn.getSource(), pType.getReferenceName());
}
private @Nullable Symbol getSymbolForName(@Nullable Node source, String name) {
if (name == null || globalScope == null) {
return null;
}
SymbolScope scope = source == null ? globalScope : getEnclosingScope(source);
if (scope == null) {
return null;
}
if (scope.isModuleScope()) {
// In the case of elements like
//
// goog.module('foo.bar');
// exports.Pinky = {};
//
// we might get fully-qualified name `foo.bar.Pinky` but when looking it up within the module
// - the symbol is just `Pinky`. So we need to remove module name to be able to find the
// symbol in module scope.
String moduleNameWithDot =
Iterables.getFirst(
compiler
.getModuleMetadataMap()
.getModulesByPath()
.get(scope.getRootNode().getSourceFileName())
.googNamespaces(),
null)
+ ".";
if (name.startsWith(moduleNameWithDot)) {
name = name.substring(moduleNameWithDot.length());
}
}
return scope.getQualifiedSlot(name);
}
/**
* Gets all symbols associated with the given type. For union types, this may be multiple symbols.
* For instance types, this will return the constructor of that instance.
*/
public List getAllSymbolsForType(JSType type) {
if (type == null) {
return ImmutableList.of();
}
UnionType unionType = type.toMaybeUnionType();
if (unionType != null) {
ImmutableList.Builder result = ImmutableList.builder();
for (JSType alt : unionType.getAlternates()) {
// Our type system never has nested unions.
Symbol altSym = getSymbolForTypeHelper(alt, true);
if (altSym != null) {
result.add(altSym);
}
}
return result.build();
}
Symbol result = getSymbolForTypeHelper(type, true);
return result == null ? ImmutableList.of() : ImmutableList.of(result);
}
/**
* Gets all symbols associated with the given type. If there is more that one symbol associated
* with the given type, return null.
*
* @param type The type.
* @param linkToCtor If true, we should link instance types back to their constructor function. If
* false, we should link instance types back to their prototype. See the comments at the top
* of this file for more information on how our internal type system is more granular than
* Symbols.
*/
private @Nullable Symbol getSymbolForTypeHelper(JSType type, boolean linkToCtor) {
if (type == null) {
return null;
}
if (type.isGlobalThisType()) {
return globalScope.getSlot(GLOBAL_THIS);
} else if (type.isNominalConstructorOrInterface()) {
return linkToCtor
? globalScope.getSlot("Function")
: getSymbolDeclaredBy(type.toMaybeFunctionType());
} else if (type.isFunctionPrototypeType()) {
FunctionType ownerFn = ((ObjectType) type).getOwnerFunction();
if (!ownerFn.isConstructor() && !ownerFn.isInterface()) {
return null;
}
return linkToCtor ? getSymbolDeclaredBy(ownerFn) : getSymbolForInstancesOf(ownerFn);
} else if (type.isInstanceType()) {
FunctionType ownerFn = ((ObjectType) type).getConstructor();
return linkToCtor ? getSymbolDeclaredBy(ownerFn) : getSymbolForInstancesOf(ownerFn);
} else if (type.isFunctionType()) {
return linkToCtor
? globalScope.getSlot("Function")
: globalScope.getQualifiedSlot("Function.prototype");
} else if (type.autoboxesTo() != null) {
return getSymbolForTypeHelper(type.autoboxesTo(), linkToCtor);
} else if (type.isEnumType()) {
return getSymbolDeclaredBy((EnumType) type);
} else {
return null;
}
}
/**
* Methods returns debug representation of the SymbolTable. It starts with the global scope and
* all its symbols recursively going to children scopes and printing their symbols.
*/
@SuppressWarnings("unused")
public String toDebugStringTree() {
// We are recursively going through scopes from global to nested and need to build parent =>
// children map as it doesn't exist at the moment.
ImmutableListMultimap.Builder childrenScopesBuilder =
ImmutableListMultimap.builder();
for (SymbolScope scope : getAllScopes()) {
if (scope.getParentScope() != null) {
childrenScopesBuilder.put(scope.getParentScope(), scope);
}
}
ImmutableListMultimap childrenScopes = childrenScopesBuilder.build();
StringBuilder builder = new StringBuilder();
// Go through all scopes that don't have parent. It's likely only Global scope.
for (SymbolScope scope : getAllScopes()) {
if (scope.getParentScope() == null) {
toDebugStringTree(builder, "", scope, childrenScopes);
}
}
// All objects/classes have property scopes. They usually don't have parents. These scopes
// confusingly are not included in "getAllScopes()" pass above.
HashSet visitedScopes = new HashSet<>(getAllScopes());
for (Symbol symbol : getAllSymbols()) {
if (symbol.propertyScope == null || visitedScopes.contains(symbol.propertyScope)) {
continue;
}
visitedScopes.add(symbol.getPropertyScope());
toDebugStringTree(builder, "", symbol.propertyScope, childrenScopes);
}
return builder.toString();
}
private void toDebugStringTree(
StringBuilder builder,
String prefix,
SymbolScope scope,
ImmutableListMultimap childrenScopes) {
builder.append(prefix).append(scope);
String childrenPrefix = prefix + " ";
boolean printedSomething = false;
if (!scope.ownSymbols.isEmpty()) {
printedSomething = true;
builder.append('\n').append(prefix).append(" Symbols:\n");
for (Symbol symbol : scope.ownSymbols.values()) {
toDebugString(builder, childrenPrefix, symbol, /* printScope= */ false);
}
}
if (childrenScopes.containsKey(scope)) {
printedSomething = true;
builder.append('\n').append(prefix).append(" Scopes:\n");
for (SymbolScope childScope : childrenScopes.get(scope)) {
toDebugStringTree(builder, childrenPrefix, childScope, childrenScopes);
}
}
if (!printedSomething) {
builder.append('\n');
}
builder.append('\n');
}
@SuppressWarnings("unused")
public String toDebugString() {
StringBuilder builder = new StringBuilder();
for (Symbol symbol : getAllSymbols()) {
toDebugString(builder, "", symbol, /* printScope= */ true);
}
return builder.toString();
}
private void toDebugString(
StringBuilder builder, String prefix, Symbol symbol, boolean printScope) {
builder.append(prefix).append("'").append(symbol.getName()).append("'");
if (printScope) {
builder.append(" in ").append(symbol.scope);
}
builder.append('\n');
int refCount = 0;
for (Reference ref : getReferences(symbol)) {
Node node = ref.getNode();
builder
.append(prefix)
.append(
SimpleFormat.format(
" Ref %d: %s line: %d col: %d len: %d %s\n",
refCount,
node.getSourceFileName(),
node.getLineno(),
node.getCharno(),
node.getLength(),
node.isIndexable() ? "" : "non indexable"));
refCount++;
}
}
/** Make sure all the given scopes in {@code otherSymbolTable} are in this symbol table. */
void addScopes(Collection scopes) {
for (S scope : scopes) {
createScopeFrom(scope);
}
}
/** Finds all the scopes and adds them to this symbol table. */
void findScopes(Node externs, Node root) {
NodeTraversal.traverseRoots(
compiler,
new NodeTraversal.AbstractScopedCallback() {
@Override
public void enterScope(NodeTraversal t) {
createScopeFrom(t.getScope());
}
@Override
public void visit(NodeTraversal t, Node n, Node p) {}
},
externs,
root);
}
/** Gets all the scopes in this symbol table. */
public Collection getAllScopes() {
return Collections.unmodifiableCollection(scopes.values());
}
/**
* Finds anonymous functions in local scopes, and gives them names and symbols. They will show up
* as local variables with names "function%0", "function%1", etc.
*/
public void addAnonymousFunctions() {
TreeSet scopes = new TreeSet<>(lexicalScopeOrdering);
for (SymbolScope scope : getAllScopes()) {
if (scope.isLexicalScope()) {
scopes.add(scope);
}
}
for (SymbolScope scope : scopes) {
addAnonymousFunctionsInScope(scope);
}
}
private void addAnonymousFunctionsInScope(SymbolScope scope) {
Symbol sym = getSymbolForScope(scope);
if (sym == null) {
// JSCompiler has no symbol for this scope. Check to see if it's a
// local function. If it is, give it a name.
Node rootNode = scope.getRootNode();
if (scope.isLexicalScope()
&& !scope.isGlobalScope()
&& rootNode != null
&& !rootNode.isFromExterns()
&& scope.getParentScope() != null
&& rootNode.isFunction()) {
SymbolScope parent = scope.getParentScope();
String innerName = "function%" + scope.getIndexInParent();
JSType type = rootNode.getJSType();
// Functions defined on anonymous objects are considered anonymous as well:
// doFoo({bar() {}});
// bar is not technically anonymous, but it's a method on an anonymous object literal so
// effectively it's anonymous/inaccessible. In this case, slightly correct rootNode to
// be a MEMBER_FUNCTION_DEF node instead of a FUNCTION node.
if (rootNode.getParent().isMemberFunctionDef()) {
rootNode = rootNode.getParent();
}
Symbol anonymousFunctionSymbol =
declareSymbol(
innerName, type, /* inferred= */ true, parent, rootNode, /* info= */ null);
scope.setSymbolForScope(anonymousFunctionSymbol);
}
}
}
/**
* Make sure all the symbols and references in {@code otherSymbolTable} are in this symbol table.
*
* Uniqueness of symbols and references is determined by the associated node.
*
*
If multiple symbol tables are mixed in, we do not check for consistency between symbol
* tables. The first symbol we see dictates the type information for that symbol.
*/
void addSymbolsFrom(
StaticSymbolTable otherSymbolTable) {
for (S otherSymbol : otherSymbolTable.getAllSymbols()) {
String name = otherSymbol.getName();
SymbolScope myScope = createScopeFrom(otherSymbolTable.getScope(otherSymbol));
StaticRef decl = findBestDeclToAdd(otherSymbolTable, otherSymbol);
Symbol mySymbol = null;
if (decl != null) {
Node declNode = decl.getNode();
// If we have a declaration node, we can ensure the symbol is declared.
mySymbol = isAnySymbolDeclared(name, declNode, myScope);
if (mySymbol == null) {
mySymbol = copySymbolTo(otherSymbol, declNode, myScope);
}
} else {
// If we don't have a declaration node, we won't be able to declare
// a symbol in this symbol table. But we may be able to salvage the
// references if we already have a symbol.
mySymbol = myScope.getOwnSlot(name);
}
if (mySymbol != null) {
for (R otherRef : otherSymbolTable.getReferences(otherSymbol)) {
if (isGoodRefToAdd(otherRef)) {
mySymbol.defineReferenceAt(otherRef.getNode());
}
}
}
}
}
/**
* Checks if any symbol is already declared at the given node and scope for the given name. If so,
* returns it.
*/
private Symbol isAnySymbolDeclared(String name, Node declNode, SymbolScope scope) {
Symbol sym = symbols.get(declNode, name);
if (sym == null) {
// Sometimes, our symbol tables will disagree on where the
// declaration node should be. In the rare case where this happens,
// trust the existing symbol.
// See SymbolTableTest#testDeclarationDisagreement.
return scope.ownSymbols.get(name);
}
return sym;
}
/** Helper for addSymbolsFrom, to determine the best declaration spot. */
private @Nullable StaticRef findBestDeclToAdd(
StaticSymbolTable otherSymbolTable, S slot) {
StaticRef decl = slot.getDeclaration();
if (isGoodRefToAdd(decl)) {
return decl;
}
for (R ref : otherSymbolTable.getReferences(slot)) {
if (isGoodRefToAdd(ref)) {
return ref;
}
}
return null;
}
/**
* Helper for addSymbolsFrom, to determine whether a reference is acceptable. A reference must be
* in the normal source tree.
*/
private boolean isGoodRefToAdd(@Nullable StaticRef ref) {
return ref != null
&& ref.getNode() != null
&& ref.getNode().getStaticSourceFile() != null
&& !NodeUtil.isInSyntheticScript(ref.getNode())
// Typechecking assigns implicitly goog.provided names a declaration node of the expr:
// For example, 'some' and 'some.name' in 'goog.provide('some.name.child');' have their
// declaration node set to the entire call node. Use the actual declaration instead.
&& !NodeUtil.isGoogProvideCall(ref.getNode());
}
private Symbol copySymbolTo(StaticSlot sym, SymbolScope scope) {
return copySymbolTo(sym, sym.getDeclaration().getNode(), scope);
}
private Symbol copySymbolTo(StaticSlot sym, Node declNode, SymbolScope scope) {
// All symbols must have declaration nodes.
checkNotNull(declNode);
return declareSymbol(
sym.getName(), getType(sym), isTypeInferred(sym), scope, declNode, sym.getJSDocInfo());
}
/**
* Replace all \ with \\ so there will be no \0 or \n in the string, then replace all '\0' (NULL)
* with \0 and all '\n' (newline) with \n.
*/
private static String sanitizeSpecialChars(String s) {
return s.replace("\\", "\\\\").replace("\0", "\\0").replace("\n", "\\n");
}
private Symbol addSymbol(
String name, JSType type, boolean inferred, SymbolScope scope, Node declNode) {
name = sanitizeSpecialChars(name);
Symbol symbol = new Symbol(name, type, inferred, scope);
Symbol replacedSymbol = symbols.put(declNode, name, symbol);
Preconditions.checkState(
replacedSymbol == null, "Found duplicate symbol %s in global index. Type %s", name, type);
replacedSymbol = scope.ownSymbols.put(name, symbol);
Preconditions.checkState(
replacedSymbol == null, "Found duplicate symbol %s in its scope. Type %s", name, type);
return symbol;
}
private Symbol declareSymbol(
String name,
@Nullable JSType type,
boolean inferred,
SymbolScope scope,
Node declNode,
@Nullable JSDocInfo info) {
Symbol symbol = addSymbol(name, type, inferred, scope, declNode);
symbol.setJSDocInfo(info);
symbol.setDeclaration(symbol.defineReferenceAt(declNode));
return symbol;
}
/**
* Merges 'from' symbol to 'to' symbol by moving all references to point to the 'to' symbol and
* removing 'from' symbol.
*/
private void mergeSymbol(Symbol from, Symbol to) {
for (Node nodeToMove : from.references.keySet()) {
if (!nodeToMove.equals(from.getDeclarationNode())) {
to.defineReferenceAt(nodeToMove);
}
}
removeSymbol(from);
}
private void removeSymbol(Symbol s) {
SymbolScope scope = getScope(s);
if (!s.equals(scope.ownSymbols.remove(s.getName()))) {
throw new IllegalStateException("Symbol not found in scope " + s);
}
if (!s.equals(symbols.remove(s.getDeclaration().getNode(), s.getName()))) {
throw new IllegalStateException("Symbol not found in table " + s);
}
// If s declares a property scope then all child symbols should be removed as well.
// For example:
// let foo = {a: 1, b: 2};
// foo declares property scope with a and b as its children. When removing foo we should also
// remove a and b.
if (s.propertyScope != null && s.equals(s.propertyScope.getSymbolForScope())) {
// Need to iterate over copy of values list because removeSymbol() will change the map
// and we'll get ConcurrentModificationException
for (Symbol childSymbol : ImmutableList.copyOf(s.propertyScope.ownSymbols.values())) {
removeSymbol(childSymbol);
}
scopes.remove(s.getDeclarationNode());
}
}
private void renameSymbol(SymbolScope scope, Symbol sym, String newName) {
Preconditions.checkState(
sym.propertyScope == null,
"Renaming supported for simple symbols that don't have property scopes.");
Symbol existingSym = scope.getSlot(newName);
if (existingSym == null) {
existingSym =
declareSymbol(
newName,
getType(sym),
isTypeInferred(sym),
scope,
sym.getDeclarationNode(),
sym.getJSDocInfo());
}
mergeSymbol(sym, existingSym);
}
/**
* Not all symbol tables record references to "namespace" objects. For example, if you have:
* goog.dom.DomHelper = function() {}; The symbol table may not record that as a reference to
* "goog.dom", because that would be redundant.
*/
void fillNamespaceReferences() {
for (Symbol symbol : getAllSymbols()) {
String qName = symbol.getName();
int rootIndex = qName.indexOf('.');
if (rootIndex == -1) {
continue;
}
Symbol root = symbol.scope.getQualifiedSlot(qName.substring(0, rootIndex));
if (root == null) {
// In theory, this should never happen, but we fail quietly anyway
// just to be safe.
continue;
}
for (Reference ref : getReferences(symbol)) {
Node currentNode = ref.getNode();
if (!currentNode.isQualifiedName()) {
continue;
}
while (currentNode.isGetProp()) {
currentNode = currentNode.getFirstChild();
String name = currentNode.getQualifiedName();
if (name == null) {
continue;
}
Symbol namespace = isAnySymbolDeclared(name, currentNode, root.scope);
if (namespace == null) {
namespace = root.scope.getQualifiedSlot(name);
}
if (namespace == null && root.scope.isGlobalScope()) {
// Originally UNKNOWN_TYPE has been always used for namespace symbols even though
// compiler does have type information attached to a node. Unclear why. Changing code to
// propery type mostly works. It only fails on Foo.prototype cases for some reason.
// It's pretty rare case when Foo.prototype defined in global scope though so for now
// just carve it out.
JSType nodeType = currentNode.getJSType();
JSType symbolType =
(nodeType != null && !nodeType.isFunctionPrototypeType())
? nodeType
: registry.getNativeType(JSTypeNative.UNKNOWN_TYPE);
namespace =
declareSymbol(
name, symbolType, true, root.scope, currentNode, null /* JsDoc info */);
}
if (namespace != null) {
namespace.defineReferenceAt(currentNode);
}
}
}
}
}
void fillPropertyScopes() {
// Collect all object symbols.
// All symbols that came from goog.module are collected separately because they will have to
// be processed first. See explanation below.
List types = new ArrayList<>();
List exports = new ArrayList<>();
// Create a property scope for each named type and each anonymous object,
// and populate it with that object's properties.
//
// We notably don't want to create a property scope for 'x' in
// var x = new Foo();
// where x is just an instance of another type.
for (Symbol sym : getAllSymbols()) {
if (needsPropertyScope(sym)) {
String name = sym.getName();
if (name.equals("exports")) {
exports.add(sym);
} else {
types.add(sym);
}
}
}
// The order of operations here is significant.
//
// When we add properties to Foo, we'll remove Foo.prototype from
// the symbol table and replace it with a fresh symbol in Foo's
// property scope. So the symbol for Foo.prototype in
// {@code instances} will be stale.
//
// If we order them in reverse lexicographical order symbols x.y and x will be processed before
// foo. This is wrong as foo is in fact property of x.y namespace. So we must process all
// module$exports$ symbols first. That's why we collected them in a separate list.
Collections.sort(types, getNaturalSymbolOrdering().reverse());
Iterable allTypes = Iterables.concat(types, exports);
// If you thought we are done with tricky case - you were wrong. There is another one!
// The problem with the same property scope appearing several times. For example when using
// aliases:
//
// const OBJ = {one: 1};
// function() {
// const alias = OBJ;
// console.log(alias.one);
// }
//
// In this case both 'OBJ' and 'alias' are considered property scopes and are candidates for
// processing even though they share the same "type" which is "{one: 1}". As they share the same
// type we need to process only one of them. To do that we build a "type => root symbol" map.
// In this case the map will be {one: 1} => OBJ. Using this map will skip 'alias' when creating
// property scopes.
//
// NOTE: we are using IdentityHashMap to compare types using == because we need to find symbols
// that point to the exact same type instance.
IdentityHashMap symbolThatDeclaresType = new IdentityHashMap<>();
for (Symbol s : allTypes) {
// Symbols are sorted in reverse order so that those with more outer scope will come later in
// the list, and therefore override those set by aliases in more inner scope. The sorting
// happens few lines above.
JSType type = s.getType();
Symbol symbolForType = getSymbolForTypeHelper(type, /* linkToCtor= */ false);
if ((type.isNominalConstructorOrInterface()
|| type.isFunctionPrototypeType()
|| type.isEnumType())
&& !s.equals(symbolForType)) {
// Some cases can't be handled by sorting. For example
//
// goog.module('some.Foo');
// class Foo {}
// exports = Foo;
//
// goog.module('some.bar');
// const Foo = goog.require('some.Foo');
//
// Both Foo symbols (declaration and alias) have the same type and equal candidates to
// become "symbol that declares Foo type". But in reality we should use the Foo in some.Foo
// module. So if symbolForType exists and not equal to current symbol - it means it's an
// alias.
continue;
}
symbolThatDeclaresType.put(s.getType(), s);
}
for (Symbol s : allTypes) {
// Create property scopes only based on "root" symbols for each type to handle aliases.
if (s.getType() == null || s.equals(symbolThatDeclaresType.get(s.getType()))) {
createPropertyScopeFor(s);
}
}
// Now we need to set the new property scope symbol to all aliases.
for (Symbol s : allTypes) {
if (s.getType() != null && symbolThatDeclaresType.get(s.getType()) != null) {
s.propertyScope = symbolThatDeclaresType.get(s.getType()).getPropertyScope();
}
}
pruneOrphanedNames();
}
private boolean needsPropertyScope(Symbol sym) {
ObjectType type = ObjectType.cast(getType(sym));
if (type == null) {
return false;
}
// Anonymous objects
if (type.getReferenceName() == null) {
return true;
}
// Constructors/prototypes
if (type.isNominalConstructorOrInterface() || type.isFunctionPrototypeType()) {
return true;
}
if (type.isEnumType()) {
return true;
}
return false;
}
/**
* Removes symbols where the namespace they're on has been removed.
*
* After filling property scopes, we may have two symbols represented in different ways. For
* example, "A.superClass_.foo" and B.prototype.foo".
*
*
This resolves that ambiguity by pruning the duplicates. If we have a lexical symbol with a
* constructor in its property chain, then we assume there's also a property path to this symbol.
* In other words, we can remove "A.superClass_.foo" because it's rooted at "A", and we built a
* property scope for "A" above.
*/
void pruneOrphanedNames() {
nextSymbol:
for (Symbol s : getAllSymbols()) {
String currentName = s.getName();
if (s.isProperty() || compiler.getModuleMap().getClosureModule(currentName) != null) {
continue;
}
int dot = -1;
while (-1 != (dot = currentName.lastIndexOf('.'))) {
currentName = currentName.substring(0, dot);
Symbol owner = s.scope.getQualifiedSlot(currentName);
if (owner != null
&& getType(owner) != null
&& (getType(owner).isNominalConstructorOrInterface()
|| getType(owner).isFunctionPrototypeType()
|| getType(owner).isEnumType())) {
removeSymbol(s);
continue nextSymbol;
}
}
}
}
/**
* Create symbols and references for all properties of types in this symbol table.
*
*
This gets a little bit tricky, because of the way this symbol table conflates "type Foo" and
* "the constructor of type Foo". So if you have:
* SymbolTable symbolTable = for("var x = new Foo();");
* Symbol x = symbolTable.getGlobalScope().getSlot("x");
* Symbol type = symbolTable.getAllSymbolsForType(getType(x)).get(0);
* Then type.getPropertyScope() will have the properties of the constructor "Foo". To get
* the properties of instances of "Foo", you will need to call:
* Symbol instance = symbolTable.getSymbolForInstancesOf(type);
* As described at the top of this file, notice that "new Foo()" and "Foo.prototype" are
* represented by the same symbol.
*/
void fillPropertySymbols(Node externs, Node root) {
new PropertyRefCollector().process(externs, root);
}
/** Index JSDocInfo. */
void fillJSDocInfo(Node externs, Node root) {
NodeTraversal.traverseRoots(
compiler, new JSDocInfoCollector(compiler.getTypeRegistry()), externs, root);
// Create references to parameters in the JSDoc.
for (Symbol sym : getAllSymbols()) {
JSDocInfo info = sym.getJSDocInfo();
if (info == null) {
continue;
}
for (Marker marker : info.getMarkers()) {
SourcePosition pos = marker.getNameNode();
if (pos == null) {
continue;
}
Node paramNode = pos.getItem();
String name = paramNode.getString();
Symbol param = getParameterInFunction(sym, name);
if (param == null) {
// There is no reference to this parameter in the actual JavaScript
// code, so we'll try to create a special JsDoc-only symbol in
// a JsDoc-only scope.
SourcePosition typePos = marker.getType();
JSType type = null;
if (typePos != null) {
type = typePos.getItem().getJSType();
}
if (sym.docScope == null) {
sym.docScope =
new SymbolScope(
null /* root */, null /* parent scope */, null /* type of this */, sym);
}
// Check to make sure there's no existing symbol. In theory, this
// should never happen, but we check anyway and fail silently
// if our assumptions are wrong. (We do not want to put the symbol
// table into an invalid state).
Symbol existingSymbol = isAnySymbolDeclared(name, paramNode, sym.docScope);
if (existingSymbol == null) {
declareSymbol(name, type, type == null, sym.docScope, paramNode, /* info= */ null);
}
} else {
param.defineReferenceAt(paramNode);
}
}
}
}
/** Records the visibility of each symbol. */
void fillSymbolVisibility(Node externs, Node root) {
CollectFileOverviewVisibility collectPass = new CollectFileOverviewVisibility(compiler);
collectPass.process(externs, root);
ImmutableMap visibilityMap =
collectPass.getFileOverviewVisibilityMap();
NodeTraversal.traverseRoots(compiler, new VisibilityCollector(visibilityMap), externs, root);
}
/**
* Build a property scope for the given symbol. Any properties of the symbol will be added to the
* property scope.
*
* It is important that property scopes are created in order from the leaves up to the root, so
* this should only be called from #fillPropertyScopes. If you try to create a property scope for
* a parent before its leaf, then the leaf will get cut and re-added to the parent property scope,
* and weird things will happen.
*/
// This function uses == to compare types to be exact same instances.
private void createPropertyScopeFor(Symbol s) {
// In order to build a property scope for s, we will need to build
// a property scope for all its implicit prototypes first. This means
// that sometimes we will already have built its property scope
// for a previous symbol.
if (s.propertyScope != null) {
return;
}
ObjectType type = getType(s) == null ? null : getType(s).toObjectType();
if (type == null) {
return;
}
// For cases like
// const foo = goog.require('some.foo');
// where createPropertyScopeFor() is called for 'foo' - instead of creating new PropertyScope we
// reuse ModuleScope corresponding to 'some.foo' module.
if (s.getName().equals("exports") && s.getDeclarationNode().isModuleBody()) {
s.propertyScope = scopes.get(s.getDeclarationNode());
return;
}
// Create an empty property scope for the given symbol, maybe with a parent scope if it has
// an implicit prototype.
SymbolScope parentPropertyScope = maybeGetParentPropertyScope(type);
s.setPropertyScope(new SymbolScope(null, parentPropertyScope, type, s));
// If this symbol represents some 'a.b.c.prototype', add any instance properties of a.b.c
// into the symbol scope.
ObjectType instanceType = type;
Iterable propNames = type.getOwnPropertyNames();
if (instanceType.isFunctionPrototypeType()) {
// Guard against modifying foo.prototype when foo is a regular (non-constructor) function.
if (instanceType.getOwnerFunction().hasInstanceType()) {
// Merge the properties of "Foo.prototype" and "new Foo()" together.
instanceType = instanceType.getOwnerFunction().getInstanceType();
propNames = Iterables.concat(propNames, instanceType.getOwnPropertyNames());
}
}
// Add all declared properties in propNames into the property scope
for (String propName : propNames) {
StaticSlot newProp = instanceType.getSlot(propName);
if (newProp.getDeclaration() == null) {
// Skip properties without declarations. We won't know how to index
// them, because we index things by node.
continue;
}
// We have symbol tables that do not do type analysis. They just try
// to build a complete index of all objects in the program. So we might
// already have symbols for things like "Foo.bar". If this happens,
// throw out the old symbol and use the type-based symbol.
Symbol oldProp =
symbols.get(newProp.getDeclaration().getNode(), s.getName() + "." + propName);
if (oldProp != null && compiler.getModuleMap().getClosureModule(oldProp.getName()) != null) {
// This handles cases like:
// goog.provide('a.b.c');
// goog.provide('a.b.c.Foo');
// Here were are creating scope for module 'a.b.c' and 'Foo' looks like a property of that
// module. But it's a module by itself - so we don't move it to the scope of 'a.b.c' and
// instead keeping 'a.b.c.Foo' in global namespace.
continue;
}
// If we've already have an entry in the table for this symbol,
// then skip it. This should only happen if we screwed up,
// and declared multiple distinct properties with the same name
// at the same node. We bail out here to be safe.
if (symbols.get(newProp.getDeclaration().getNode(), newProp.getName()) != null) {
if (logger.isLoggable(Level.FINE)) {
logger.fine("Found duplicate symbol " + newProp);
}
continue;
}
Symbol newSym = copySymbolTo(newProp, s.propertyScope);
if (oldProp != null) {
if (newSym.getJSDocInfo() == null) {
newSym.setJSDocInfo(oldProp.getJSDocInfo());
}
newSym.setPropertyScope(oldProp.propertyScope);
for (Reference ref : oldProp.references.values()) {
newSym.defineReferenceAt(ref.getNode());
}
// All references/scopes from oldProp were updated to use the newProp. Time to remove
// oldProp.
removeSymbol(oldProp);
}
}
}
/**
* If this type has an implicit prototype set, returns the SymbolScope corresponding to the
* properties of the implicit prototype. Otherwise returns null.
*
* Note that currently we only handle cases where the implicit prototype is a) a class or b) is
* an instance object.
*/
private @Nullable SymbolScope maybeGetParentPropertyScope(ObjectType symbolObjectType) {
ObjectType proto = symbolObjectType.getImplicitPrototype();
if (proto == null || proto == symbolObjectType) {
return null;
}
final Symbol parentSymbol;
if (isEs6ClassConstructor(proto)) {
// given `class Foo {} class Bar extends Foo {}`, `Foo` is the implicit prototype of `Bar`.
parentSymbol = getSymbolDeclaredBy(proto.toMaybeFunctionType());
} else if (proto.getConstructor() != null) {
// given
// /** @constructor */ function Foo() {}
// /** @constructor */ function Bar() {}
// goog.inherits(Bar, Foo);
// the implicit prototype of Bar.prototype is the instance of Foo.
parentSymbol = getSymbolForInstancesOf(proto.getConstructor());
} else {
return null;
}
if (parentSymbol == null) {
return null;
}
createPropertyScopeFor(parentSymbol);
return parentSymbol.getPropertyScope();
}
private boolean isEs6ClassConstructor(JSType type) {
return type.isFunctionType()
&& type.toMaybeFunctionType().getSource() != null
&& type.toMaybeFunctionType().getSource().isClass();
}
/** Fill in references to "this" variables. */
void fillThisReferences(Node externs, Node root) {
new ThisRefCollector().process(externs, root);
}
/** Fill in references to "super" variables. */
void fillSuperReferences(Node externs, Node root) {
NodeTraversal.Callback collectSuper =
new AbstractPostOrderCallback() {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// Process only 'super' nodes with types.
if (!n.isSuper() || n.getJSType() == null) {
return;
}
Symbol classSymbol = getSymbolForTypeHelper(n.getJSType(), /* linkToCtor= */ false);
if (classSymbol != null) {
classSymbol.defineReferenceAt(n);
}
}
};
NodeTraversal.traverseRoots(compiler, collectSuper, externs, root);
}
/**
* This function connects imported symbol back to its declaration. For example:
*
*
* goog.module('some.Foo');
* class Foo {}
* exports = Foo;
*
* goog.module('some.bar');
* const Foo = goog.require('some.Foo');
*
*
* This method will add a reference from the `Foo` symbol in `some.Bar` module pointing to the
* `class Foo` in `some.Foo` module.
*/
private void addRefsInGoogRequireStatement(Node n, Map googModuleScopes) {
if (compiler.getOptions().shouldRewriteModules()) {
// When modules are rewritten - there is no need to connect imported names back to definitions
// as that was done with the help of Preprocessor tables in ClosureRewriteModule pass.
return;
}
Node require = n.getLastChild();
String moduleName = require.getSecondChild().getString();
Module module = compiler.getModuleMap().getClosureModule(moduleName);
ModuleType moduleType = module == null ? null : module.metadata().moduleType();
SymbolScope moduleScope = googModuleScopes.get(moduleName);
if (n.isName()) {
// This is `const Foo = goog.require('some.Foo');` case.
// The type of Foo is either a class/interface in which case we can find its symbol that
// declared class/interface.
Symbol declaration = getSymbolForTypeHelper(n.getJSType(), false);
if (declaration != null) {
declaration.defineReferenceAt(n);
}
// This import might be for a constant like `const constant = goog.require('some.constant');`.
// Try to find it in the corresponding definition in module.
switch (moduleType) {
case GOOG_MODULE:
case LEGACY_GOOG_MODULE:
// For goog.module search for 'exports' node and use that it as declaration. It would be
// better to use right-handside of exports: `exports = constant;` but it's difficult to
// get symbol for the right-handside. So do a more limited approach.
declaration = moduleScope.getOwnSlot("exports");
break;
case GOOG_PROVIDE:
// For goog.provide `some.constant` should be defined in global namespace.
declaration = getSymbolForName(null, moduleName);
break;
default:
// skip
}
if (declaration != null) {
declaration.defineReferenceAt(n);
}
} else if (n.isDestructuringLhs()) {
// This is `const {one} = goog.require('some.foo')` case.
// For each imported symbol in destructuring we need to find corresponding declaration symbol
// in `some.foo` namespace and connect them.
checkState(n.getFirstChild().isObjectPattern());
// Iterate through all symbols in destructuring.
for (Node stringKey : n.getFirstChild().children()) {
checkState(stringKey.isStringKey());
String varName = stringKey.getString();
Symbol varDeclaration = null;
// AST of goog.module and goog.provide differs significantly so we need to lookup variables
// differently.
switch (moduleType) {
case GOOG_MODULE:
case LEGACY_GOOG_MODULE:
varDeclaration = moduleScope.getOwnSlot(varName);
break;
case GOOG_PROVIDE:
varDeclaration = getSymbolForName(null, moduleName + "." + varName);
break;
default:
// skip
}
if (varDeclaration != null) {
varDeclaration.defineReferenceAt(stringKey);
}
}
}
}
/**
* Connects goog.module/goog.provide calls with goog.require/goog.requireType. For each
* goog.module/goog.provide call creates a symbol and all goog.require/goog.requireType added as
* references.
*/
void fillGoogProvideModuleRequires(Node externs, Node root) {
// small optimization to keep symbols created within this function for fast access instead of
// going through SymbolTable.getSymbolForName() every time.
Map declaredNamespaces = new HashMap<>();
// Map containind goog.module names to Scope object representing them. For goog.provide
// namespaces there is no scope as elements of goog.provide are global.
Map moduleScopes = new HashMap<>();
Predicate looksLikeGoogCall =
(Node n) -> {
if (!n.isCall()) {
return false;
}
Node left = n.getFirstChild();
Node arg = n.getSecondChild();
// We want only nodes of type `goog.xyz('somestring')`.
if (!(left.isGetProp()
&& left.getFirstChild().isName()
&& left.getFirstChild().getString().equals("goog"))
|| arg == null
|| !arg.isStringLit()) {
return false;
}
return true;
};
NodeTraversal.Callback collectModuleScopes =
new AbstractPostOrderCallback() {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (!looksLikeGoogCall.test(n)) {
return;
}
Node arg = n.getSecondChild();
String namespaceName = "ns$" + arg.getString();
switch (n.getFirstChild().getString()) {
case "module":
case "provide":
Symbol ns =
declareSymbol(
namespaceName,
/* type= */ null,
/* inferred= */ false,
getGlobalScope(),
arg,
/* info= */ null);
declaredNamespaces.put(namespaceName, ns);
if (n.getGrandparent().isModuleBody()) {
moduleScopes.put(arg.getString(), scopes.get(n.getGrandparent()));
}
break;
default:
// do nothing. Some other goog.xyz call.
}
}
};
NodeTraversal.Callback processRequireStatements =
new AbstractPostOrderCallback() {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (!looksLikeGoogCall.test(n)) {
return;
}
Node arg = n.getSecondChild();
String namespaceName = "ns$" + arg.getString();
switch (n.getFirstChild().getString()) {
case "require":
case "requireType":
case "forwardDeclare":
addRefsInGoogRequireStatement(n.getParent(), moduleScopes);
Symbol symbol = declaredNamespaces.get(namespaceName);
// We expect that namespace was already processed by that point, but in some broken
// code it might be missing. In which case just skip it.
if (symbol != null) {
symbol.defineReferenceAt(arg);
}
break;
default:
// do nothing. Some other goog.xyz call.
}
}
};
NodeTraversal.traverseRoots(compiler, collectModuleScopes, externs, root);
NodeTraversal.traverseRoots(compiler, processRequireStatements, externs, root);
}
/**
* Flattens symbols within a module scope (goog.module). In goog.module we often have different
* variations of declaring Foo, exports.Foo, exports = {Foo}. In some cases there are both Foo and
* exports.Foo = Foo while in others there is only exports.Foo. Semantically they are the same to
* the user so we flatten them into Foo. All 'exports.Foo' symbols renamed or merged into 'Foo'
* (depending on whether it already exists). That way we get more predictable table which is
* required for better index data and integration with other languages, e.g. JS <=> TS indexing.
*
* This is not a correct operation in 100% of times. For example it will produce very incorrect
* result for:
*
*
* class Foo {}
* exports.Foo = NotFoo;
*
*
* But that should be very rare case and the code is misleading and should be avoided.
*/
void flattenGoogModuleExports() {
for (SymbolScope moduleScope : getAllScopes()) {
if (!moduleScope.isModuleScope()) {
continue;
}
for (Symbol sym : ImmutableList.copyOf(moduleScope.ownSymbols.values())) {
if (sym.getName().startsWith("exports.")) {
renameSymbol(moduleScope, sym, sym.getName().substring("exports.".length()));
}
}
}
}
/*
* Checks whether symbol is a quoted object literal key. In the following object:
*
* var foo = {'one': 1, two: 2};
*
* 'one' is quoted key. while two is not.
*/
private boolean isSymbolAQuotedObjectKey(Symbol symbol) {
Node node = symbol.getDeclarationNode();
return node != null && node.isStringKey() && node.isQuotedStringKey();
}
/**
* Heuristic method to check whether symbol was created by DeclaredGlobalExternsOnWindow.java
* pass.
*/
private boolean isSymbolDuplicatedExternOnWindow(Symbol symbol) {
Node node = symbol.getDeclarationNode();
// Check that node is of type "window.foo";
return !node.isIndexable()
&& node.isGetProp()
&& node.getFirstChild().isName()
&& node.getFirstChild().getString().equals("window");
}
/**
* DeclaredGLobalExternsOnWindow.java pass duplicates all global variables so that:
*
*
* var foo;
*
*
* becomes
*
*
* var foo;
* window.foo;
*
*
* This function finds all such cases and merges window.foo symbol back to foo. It changes
* window.foo references to point to foo symbol.
*/
private void mergeExternSymbolsDuplicatedOnWindow() {
// To find duplicated symbols we rely on the fact that duplicated symbol share the same
// source position as original symbol and going to use filename => sourcePosition => symbol
// table.
Table externSymbols = HashBasedTable.create();
for (Symbol symbol : ImmutableList.copyOf(symbols.values())) {
if (symbol.getDeclarationNode() == null
|| symbol.getDeclarationNode().getStaticSourceFile() == null
|| !symbol.getDeclarationNode().getStaticSourceFile().isExtern()) {
continue;
}
String sourceFile = symbol.getSourceFileName();
int position = symbol.getDeclarationNode().getSourcePosition();
if (!externSymbols.contains(sourceFile, position)) {
externSymbols.put(sourceFile, position, symbol);
continue;
}
Symbol existingSymbol = externSymbols.get(sourceFile, position);
// Consider 2 possibilies: either symbol or existingSymbol might be the generated symbol we
// are looking for.
if (isSymbolDuplicatedExternOnWindow(existingSymbol)) {
mergeSymbol(existingSymbol, symbol);
externSymbols.put(sourceFile, position, symbol);
} else if (isSymbolDuplicatedExternOnWindow(symbol)) {
mergeSymbol(symbol, existingSymbol);
}
}
}
/**
* Removes various generated symbols that are invisible to users and pollute or mess up index.
* Jscompiler does transpilations that might introduce extra nodes/symbols. Most of these symbols
* should not get into final SymbolTable because SymbolTable should contain only symbols that
* correspond to a symbol in original source code (before transpilation).
*/
void removeGeneratedSymbols() {
// Need to iterate over copy of values list because removeSymbol() will change the map
// and we'll get ConcurrentModificationException
for (Symbol symbol : ImmutableList.copyOf(symbols.values())) {
if (isSymbolAQuotedObjectKey(symbol)) {
// Quoted object keys are not considered symbols. Only unquoted keys and dot-access
// properties are considered symbols. Remove the quoted key.
boolean symbolAlreadyRemoved = !getScope(symbol).ownSymbols.containsKey(symbol.getName());
if (!symbolAlreadyRemoved) {
removeSymbol(symbol);
}
} else if (symbol.getDeclarationNode() != null
&& symbol.getDeclarationNode().isModuleBody()) {
// Symbols that represent whole module (goog.module) aren't needed for indexing. We already
// recorded imports/references of that module in fillGoogProvideModuleRequires() function.
// Individual exported functions/variables also have their own symbols.
removeSymbol(symbol);
}
}
mergeExternSymbolsDuplicatedOnWindow();
}
/**
* Given a scope from another symbol table, returns the {@code SymbolScope} rooted at the same
* node. Creates one if it doesn't exist yet.
*/
private SymbolScope createScopeFrom(StaticScope otherScope) {
Node otherScopeRoot = otherScope.getRootNode();
SymbolScope myScope = scopes.get(otherScopeRoot);
if (myScope == null) {
StaticScope otherScopeParent = otherScope.getParentScope();
// If otherScope is a global scope, and we already have a global scope,
// then something has gone seriously wrong.
//
// Not all symbol tables are rooted at the same global node, and
// we do not want to mix and match symbol tables that are rooted
// differently.
if (otherScopeParent == null) {
// The global scope must be created before any local scopes.
checkState(globalScope == null, "Global scopes found at different roots");
}
myScope =
new SymbolScope(
otherScopeRoot,
otherScopeParent == null ? null : createScopeFrom(otherScopeParent),
getTypeOfThis(otherScope),
null);
scopes.put(otherScopeRoot, myScope);
if (myScope.isGlobalScope()) {
globalScope = myScope;
}
}
return myScope;
}
/** A symbol-table entry */
public static final class Symbol extends SimpleSlot {
// Use a linked hash map, so that the results are deterministic
// (and so the declaration always comes first).
private final Map references = new LinkedHashMap<>();
private final SymbolScope scope;
private @Nullable SymbolScope propertyScope = null;
private @Nullable Reference declaration = null;
private @Nullable JSDocInfo docInfo = null;
/**
* Stored separately from {@link #docInfo}, because the visibility stored in JSDocInfo is not
*/
private @Nullable Visibility visibility = null;
// A scope for symbols that are only documented in JSDoc.
private @Nullable SymbolScope docScope = null;
Symbol(String name, JSType type, boolean inferred, SymbolScope scope) {
super(name, type, inferred);
this.scope = scope;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Symbol)) {
return false;
}
Symbol other = (Symbol) o;
return isTypeInferred() == other.isTypeInferred()
&& Objects.equals(getName(), other.getName())
&& Objects.equals(getType(), other.getType())
&& Objects.equals(scope, other.scope);
}
@Override
public int hashCode() {
return Objects.hash(Boolean.valueOf(isTypeInferred()), getName(), getType(), scope);
}
@Override
public Reference getDeclaration() {
return declaration;
}
public FunctionType getFunctionType() {
return JSType.toMaybeFunctionType(getType());
}
public Reference defineReferenceAt(Node n) {
return references.computeIfAbsent(n, (Node k) -> new Reference(this, k));
}
/** Sets the declaration node. May only be called once. */
void setDeclaration(Reference ref) {
checkState(this.declaration == null);
this.declaration = ref;
}
public @Nullable Node getDeclarationNode() {
return declaration == null ? null : declaration.getNode();
}
public @Nullable String getSourceFileName() {
Node n = getDeclarationNode();
return n == null ? null : n.getSourceFileName();
}
public SymbolScope getPropertyScope() {
return propertyScope;
}
void setPropertyScope(SymbolScope scope) {
this.propertyScope = scope;
if (scope != null) {
this.propertyScope.setSymbolForScope(this);
}
}
@Override
public JSDocInfo getJSDocInfo() {
return docInfo;
}
void setJSDocInfo(JSDocInfo info) {
this.docInfo = info;
}
public @Nullable Visibility getVisibility() {
return this.visibility;
}
void setVisibility(Visibility v) {
this.visibility = v;
}
/** Whether this is a property of another variable. */
public boolean isProperty() {
return scope.isPropertyScope();
}
/** Whether this is a variable in a lexical scope. */
public boolean isLexicalVariable() {
return scope.isLexicalScope();
}
/** Whether this is a variable that's only in JSDoc. */
public boolean isDocOnlyParameter() {
return scope.isDocScope();
}
@Override
public String toString() {
Node n = getDeclarationNode();
int lineNo = n == null ? -1 : n.getLineno();
return getName() + "@" + getSourceFileName() + ":" + lineNo;
}
}
/** Reference */
public static final class Reference extends SimpleReference {
Reference(Symbol symbol, Node node) {
super(symbol, node);
}
}
/** Scope of a symbol */
public static final class SymbolScope {
private final Node rootNode;
private final SymbolScope parent;
private final JSType typeOfThis;
private final Map ownSymbols = new LinkedHashMap<>();
private final int scopeDepth;
// Index of current scope in the parent scope. Used to generate unique names for variables
// having the same name but defined in different scopes.
private final int indexInParent;
private int numberOfChildScopes = 0;
// The symbol associated with a property scope or doc scope.
private Symbol mySymbol;
SymbolScope(
@Nullable Node rootNode,
@Nullable SymbolScope parent,
@Nullable JSType typeOfThis,
@Nullable Symbol mySymbol) {
this.rootNode = rootNode;
this.parent = parent;
this.typeOfThis = typeOfThis;
this.scopeDepth = parent == null ? 0 : (parent.getScopeDepth() + 1);
this.mySymbol = mySymbol;
if (parent == null) {
this.indexInParent = 0;
} else {
this.indexInParent = parent.numberOfChildScopes;
parent.numberOfChildScopes++;
}
}
Symbol getSymbolForScope() {
return mySymbol;
}
void setSymbolForScope(Symbol sym) {
this.mySymbol = sym;
}
/** Gets a unique index for the symbol in this scope. */
public int getIndexOfSymbol(Symbol sym) {
return Iterables.indexOf(ownSymbols.values(), Predicates.equalTo(sym));
}
Node getRootNode() {
return rootNode;
}
public SymbolScope getParentScope() {
return parent;
}
/**
* Get the slot for a fully-qualified name (e.g., "a.b.c") by trying to find property scopes at
* each part of the path.
*/
public @Nullable Symbol getQualifiedSlot(String name) {
Symbol fullyNamedSym = getSlot(name);
if (fullyNamedSym != null) {
return fullyNamedSym;
}
int dot = name.lastIndexOf('.');
if (dot != -1) {
Symbol owner = getQualifiedSlot(name.substring(0, dot));
if (owner != null && owner.getPropertyScope() != null) {
return owner.getPropertyScope().getSlot(name.substring(dot + 1));
}
}
return null;
}
public @Nullable Symbol getSlot(String name) {
Symbol own = getOwnSlot(name);
if (own != null) {
return own;
}
Symbol ancestor = parent == null ? null : parent.getSlot(name);
if (ancestor != null) {
return ancestor;
}
return null;
}
Symbol getOwnSlot(String name) {
return ownSymbols.get(name);
}
public JSType getTypeOfThis() {
return typeOfThis;
}
public boolean isGlobalScope() {
return getParentScope() == null && getRootNode() != null;
}
public boolean isModuleScope() {
return getRootNode() != null && getRootNode().isModuleBody();
}
/**
* Returns whether this is a doc scope. A doc scope is a table for symbols that are documented
* solely within a JSDoc comment.
*/
public boolean isDocScope() {
return getRootNode() == null && mySymbol != null && mySymbol.docScope == this;
}
public boolean isPropertyScope() {
return getRootNode() == null && !isDocScope();
}
public boolean isLexicalScope() {
return getRootNode() != null;
}
public boolean isBlockScope() {
return getRootNode() != null && NodeUtil.createsBlockScope(getRootNode());
}
public int getScopeDepth() {
return scopeDepth;
}
public int getIndexInParent() {
return indexInParent;
}
@Override
public String toString() {
Node n = getRootNode();
if (isGlobalScope()) {
return "GlobalScope";
} else if (n != null) {
String type = "Scope";
if (isModuleScope()) {
type = "ModuleScope";
} else if (isBlockScope()) {
type = "BlockScope";
} else if (isLexicalScope()) {
type = "LexicalScope";
}
return type + "@" + n.getSourceFileName() + ":" + n.getLineno();
} else {
return "PropertyScope@" + getSymbolForScope();
}
}
}
private class PropertyRefCollector extends AbstractPostOrderCallback implements CompilerPass {
@Override
public void process(Node externs, Node root) {
NodeTraversal.traverseRoots(compiler, this, externs, root);
}
private boolean maybeDefineReference(Node n, String propName, Symbol ownerSymbol) {
// getPropertyScope() will be null in some rare cases where there
// are no extern declarations for built-in types (like Function).
if (ownerSymbol != null && ownerSymbol.getPropertyScope() != null) {
Symbol prop = ownerSymbol.getPropertyScope().getSlot(propName);
if (prop != null) {
prop.defineReferenceAt(n);
return true;
}
}
return false;
}
// Try to find the symbol by its fully qualified name.
private boolean tryDefineLexicalQualifiedNameRef(String name, Node n) {
if (name != null) {
Symbol lexicalSym = getEnclosingScope(n).getQualifiedSlot(name);
if (lexicalSym != null) {
lexicalSym.defineReferenceAt(n);
return true;
}
}
return false;
}
// Try to remove a reference by its fully qualified name.
// If the symbol has no references left, remove it completely.
private void tryRemoveLexicalQualifiedNameRef(String name, Node n) {
if (name != null) {
Symbol lexicalSym = getEnclosingScope(n).getQualifiedSlot(name);
if (lexicalSym != null
&& lexicalSym.isLexicalVariable()
&& lexicalSym.getDeclaration().getNode() == n) {
removeSymbol(lexicalSym);
}
}
}
private boolean maybeDefineTypedReference(Node n, String propName, JSType owner) {
if (owner.isGlobalThisType()) {
Symbol sym = globalScope.getSlot(propName);
if (sym != null) {
sym.defineReferenceAt(n);
return true;
}
} else if (owner.isNominalConstructorOrInterface()) {
return maybeDefineReference(n, propName, getSymbolDeclaredBy(owner.toMaybeFunctionType()));
} else if (owner.isEnumType()) {
return maybeDefineReference(n, propName, getSymbolDeclaredBy(owner.toMaybeEnumType()));
} else {
boolean defined = false;
for (Symbol ctor : getAllSymbolsForType(owner)) {
if (maybeDefineReference(n, propName, getSymbolForInstancesOf(ctor))) {
defined = true;
}
}
if (defined) {
return true;
}
}
// Handle cases like accessing properties on a imported module.
// const foo = goog.require('some.module.foo');
// foo.doSomething();
// here n is foo, propName is doSomething and owner is module type.
if (owner.isObjectType() && owner.toMaybeObjectType() != null) {
Node propNodeDecl = owner.assertObjectType().getPropertyNode(propName);
if (propNodeDecl == null) {
return false;
}
// There is no handy way to find symbol object the given property node. So we do
// property node => namespace node => namespace symbol => property symbol.
if (propNodeDecl != null && propNodeDecl.isGetProp()) {
Node namespace = propNodeDecl.getFirstChild();
Symbol namespaceSym = getSymbolForName(namespace, namespace.getQualifiedName());
if (namespaceSym != null && namespaceSym.getPropertyScope() != null) {
Symbol propSym = namespaceSym.getPropertyScope().getSlot(propName);
if (propSym != null && propSym.getDeclarationNode() != n) {
propSym.defineReferenceAt(n);
return true;
}
}
}
// Here handle the case of goog.module exports that have shape of:
//
// goog.module('foo.bar');
// function doOne() { ... }
// exports = {doOne};
//
// propNodeDecl is `doOne` node on the last line with exports. From that node and propName
// `doOne` we need to get symbol for the `function doOne`. To achieve that we get scope of
// `doOne` node which should be whole module scope and look for symbol with corresponding
// name. This relies on the assumption that function name in module scope exported name. But
// if export is renamed: `exports = {doOneRenamed: doOne}`, then this approach will fail.
SymbolScope propNodeDeclScope = getEnclosingScope(propNodeDecl);
if (propNodeDeclScope == null || !propNodeDeclScope.isModuleScope()) {
return false;
}
Symbol symbol = getSymbolForName(propNodeDecl, propName);
if (symbol != null && symbol.getDeclarationNode() != n) {
symbol.defineReferenceAt(n);
return true;
}
}
return false;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// There are two ways to define a property reference:
// 1) As a fully qualified lexical symbol (e.g., x.y)
// 2) As a property of another object (e.g., x's y)
// Property definitions should take precedence over lexical
// definitions. e.g., for "a.b", it's more useful to record
// this as "property b of the type of a", than as "symbol a.b".
if (n.isGetProp()) {
JSType owner = n.getFirstChild().getJSType();
if (owner != null) {
boolean defined = maybeDefineTypedReference(n, n.getString(), owner);
if (defined) {
tryRemoveLexicalQualifiedNameRef(n.getQualifiedName(), n);
return;
}
}
tryDefineLexicalQualifiedNameRef(n.getQualifiedName(), n);
} else if (n.isStringKey()) {
JSType owner = parent.getJSType();
if (owner != null) {
boolean defined = maybeDefineTypedReference(n, n.getString(), owner);
if (defined) {
tryRemoveLexicalQualifiedNameRef(NodeUtil.getBestLValueName(n), n);
return;
}
}
tryDefineLexicalQualifiedNameRef(NodeUtil.getBestLValueName(n), n);
}
}
}
private class ThisRefCollector extends NodeTraversal.AbstractScopedCallback
implements CompilerPass {
// The 'this' symbols in the current scope chain.
//
// If we don't know how to declare 'this' in a scope chain,
// then null should be on the stack. But this should be a rare
// occurrence. We should strive to always be able to come up
// with some symbol for 'this'.
//
// This list only has entries for function scopes and the global scope, and doesn't store a
// separate `this` value for other block scopes.
private final List thisStack = new ArrayList<>();
@Override
public void process(Node externs, Node root) {
NodeTraversal.traverseRoots(compiler, this, externs, root);
}
@Override
public void enterScope(NodeTraversal t) {
Symbol symbol = null;
if (t.inGlobalScope()) {
// Declare the global this at the first input root.
// This is a bizarre place to put it, but we need some
// location with a real file path (because all symbols
// must have a path).
// Note that root.lastChild.firstChild is the first non-extern input.
Node firstInputRoot = t.getScopeRoot().getLastChild().getFirstChild();
if (firstInputRoot != null) {
symbol =
addSymbol(
GLOBAL_THIS,
registry.getNativeType(JSTypeNative.GLOBAL_THIS),
false /* declared */,
globalScope,
firstInputRoot);
symbol.setDeclaration(new Reference(symbol, firstInputRoot));
}
thisStack.add(symbol);
} else if (t.getScopeRoot().isFunction()) {
// Otherwise, declare a "this" property when possible.
Node scopeRoot = t.getScopeRoot();
SymbolScope scope = scopes.get(scopeRoot);
if (NodeUtil.getFunctionBody(scopeRoot).hasChildren()) {
Symbol scopeSymbol = getSymbolForScope(scope);
if (scopeSymbol != null) {
SymbolScope propScope = scopeSymbol.getPropertyScope();
if (propScope != null) {
// If a function is assigned multiple times, we only want
// one addressable "this" symbol.
symbol = propScope.getOwnSlot("this");
if (symbol == null) {
JSType rootType = t.getScopeRoot().getJSType();
FunctionType fnType = rootType == null ? null : rootType.toMaybeFunctionType();
JSType type = fnType == null ? null : fnType.getTypeOfThis();
symbol = addSymbol("this", type, /* inferred= */ false, scope, scopeRoot);
}
}
}
} else {
logger.fine("Skipping empty function: " + scopeRoot);
}
thisStack.add(symbol);
}
// Don't add to the `thisStack` for other block scopes.
}
@Override
public void exitScope(NodeTraversal t) {
if (t.inGlobalScope() || t.getScopeRoot().isFunction()) {
thisStack.remove(thisStack.size() - 1);
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (!n.isThis()) {
return;
}
Symbol symbol = Iterables.getLast(thisStack);
if (symbol != null) {
Reference ref = symbol.defineReferenceAt(n);
if (symbol.getDeclaration() == null) {
symbol.setDeclaration(ref);
}
}
}
}
/** Collects references to types in JSDocInfo. */
private class JSDocInfoCollector extends AbstractPostOrderCallback {
private final JSTypeRegistry typeRegistry;
private JSDocInfoCollector(JSTypeRegistry registry) {
this.typeRegistry = registry;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
JSDocInfo info = n.getJSDocInfo();
if (info == null) {
return;
}
docInfos.add(n);
for (Node typeAst : info.getTypeNodes()) {
SymbolScope scope = scopes.get(t.getScopeRoot());
visitTypeNode(info.getTemplateTypes(), scope == null ? globalScope : scope, typeAst);
}
}
private boolean isNativeSourcelessType(String name) {
switch (name) {
case "null":
case "undefined":
case "void":
return true;
default:
return false;
}
}
public void visitTypeNode(
ImmutableMap templateTypeNames, SymbolScope scope, Node n) {
if (n.isStringLit()
&& !isNativeSourcelessType(n.getString())
&& !templateTypeNames.containsKey(n.getString())) {
Symbol symbol = lookupPossiblyDottedName(scope, n.getString());
if (symbol != null) {
Node ref = n;
String typeString = n.getOriginalName() != null ? n.getOriginalName() : n.getString();
// Qualified names in JSDoc types are kept as a single string: "foo.bar.MyType". In order
// to have good indexing we need to make the SymbolTable reference include only "MyType"
// instead of "foo.bar.MyType". To do that we clone the type node and change the source
// info of the clone to include only the last part of the type ("MyType").
if (typeString.contains(".")) {
String lastPart = typeString.substring(typeString.lastIndexOf('.') + 1);
Node copy = n.cloneNode();
copy.setLinenoCharno(
copy.getLineno(), copy.getCharno() + copy.getLength() - lastPart.length());
copy.setLength(lastPart.length());
ref = copy;
}
symbol.defineReferenceAt(ref);
}
}
for (Node child = n.getFirstChild(); child != null; child = child.getNext()) {
visitTypeNode(templateTypeNames, scope, child);
}
}
// TODO(peterhal): @template types.
private Symbol lookupPossiblyDottedName(SymbolScope scope, String dottedName) {
// Try the dotted name to start.
Symbol result = scope.getQualifiedSlot(dottedName);
if (result != null) {
return result;
}
// If we can't find this type, it might be a reference to a
// primitive type (like {string}). Autobox it to check.
JSType type = typeRegistry.getGlobalType(dottedName);
JSType autobox = type == null ? null : type.autoboxesTo();
return autobox == null
? getSymbolForTypeHelper(type, true)
: getSymbolForTypeHelper(autobox, true);
}
}
/** Collects the visibility information for each name/property. */
private class VisibilityCollector extends AbstractPostOrderCallback {
private final ImmutableMap fileVisibilityMap;
private VisibilityCollector(ImmutableMap fileVisibilityMap) {
this.fileVisibilityMap = fileVisibilityMap;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isName()) {
visitName(t, n);
} else if (n.isGetProp()) {
visitProperty(n, parent);
}
}
private void visitName(NodeTraversal t, Node n) {
Symbol symbol = symbols.get(n, n.getString());
if (symbol == null) {
return;
}
// Visibility already set.
if (symbol.getVisibility() != null) {
return;
}
Var var = t.getScope().getVar(n.getString());
if (var == null) {
return;
}
Visibility v = AccessControlUtils.getEffectiveNameVisibility(n, var, fileVisibilityMap);
if (v == null) {
return;
}
symbol.setVisibility(v);
}
private void visitProperty(Node getprop, Node parent) {
String propertyName = getprop.getString();
Symbol symbol = symbols.get(getprop, propertyName);
if (symbol == null) {
return;
}
// Visibility already set.
if (symbol.getVisibility() != null) {
return;
}
JSType jsType = getprop.getFirstChild().getJSType();
if (jsType == null) {
return;
}
boolean isOverride =
parent.getJSDocInfo() != null && parent.isAssign() && parent.getFirstChild() == getprop;
if (isOverride) {
// Don't bother with AccessControlUtils for overridden properties.
// AccessControlUtils currently has complicated logic for detecting
// visibility mismatches for overridden properties that is still
// too tightly coupled to CheckAccessControls. TODO(brndn): simplify.
symbol.setVisibility(Visibility.INHERITED);
} else {
ObjectType referenceType = ObjectType.cast(jsType.dereference());
Visibility v =
AccessControlUtils.getEffectivePropertyVisibility(
getprop, referenceType, fileVisibilityMap);
if (v == null) {
return;
}
symbol.setVisibility(v);
}
}
}
// Comparators
private final Ordering sourceNameOrdering = Ordering.natural().nullsFirst();
private final Ordering nodeOrdering =
new Ordering() {
@Override
public int compare(Node a, Node b) {
int result = sourceNameOrdering.compare(a.getSourceFileName(), b.getSourceFileName());
if (result != 0) {
return result;
}
// Source position is a bit mask of line in the top 4 bits, so this
// is a quick way to compare order without computing absolute position.
return a.getSourcePosition() - b.getSourcePosition();
}
};
private final Ordering lexicalScopeOrdering =
new Ordering() {
@Override
public int compare(SymbolScope a, SymbolScope b) {
checkState(a.isLexicalScope() && b.isLexicalScope(), "We can only sort lexical scopes");
int result = nodeOrdering.compare(a.getRootNode(), b.getRootNode());
if (result != 0) {
return result;
}
// If result = 0 it means that rootNodes either the same or that one of them was added
// by compiler during transpilation and uses the same source info as original node.
// In that case compare scopes by depth because one of them (probably generated one) is
// a child of the other scope.
// TODO(b/62349230): remove this once transpilation is disabled. No two different scopes
// should have the same source info.
return a.getScopeDepth() - b.getScopeDepth();
}
};
private final Ordering symbolOrdering =
new Ordering() {
@Override
public int compare(Symbol a, Symbol b) {
SymbolScope scopeA = getScope(a);
SymbolScope scopeB = getScope(b);
// More deeply nested symbols should go later.
int result = getLexicalScopeDepth(scopeA) - getLexicalScopeDepth(scopeB);
if (result != 0) {
return result;
}
// After than, just use lexicographic ordering.
// This ensures "a.b" comes before "a.b.c".
return a.getName().compareTo(b.getName());
}
};
/**
* For a lexical scope, just returns the normal scope depth.
*
* For a property scope, returns the number of scopes we have to search to find the nearest
* lexical scope, plus that lexical scope's depth.
*
*
For a doc info scope, returns 0.
*/
private int getLexicalScopeDepth(SymbolScope scope) {
if (scope.isLexicalScope() || scope.isDocScope()) {
return scope.getScopeDepth();
} else {
checkState(scope.isPropertyScope());
Symbol sym = scope.getSymbolForScope();
checkNotNull(sym);
return getLexicalScopeDepth(getScope(sym)) + 1;
}
}
private @Nullable JSType getType(StaticSlot sym) {
if (sym instanceof StaticTypedSlot) {
return ((StaticTypedSlot) sym).getType();
}
return null;
}
private @Nullable JSType getTypeOfThis(StaticScope s) {
if (s instanceof StaticTypedScope) {
return ((StaticTypedScope) s).getTypeOfThis();
}
return null;
}
private boolean isTypeInferred(StaticSlot sym) {
if (sym instanceof StaticTypedSlot) {
return ((StaticTypedSlot) sym).isTypeInferred();
}
return true;
}
}