/*
* 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 com.google.javascript.jscomp.CheckLevel;
import com.google.javascript.jscomp.GlobalNamespace.Name;
import com.google.javascript.jscomp.GlobalNamespace.Ref;
import com.google.javascript.rhino.JSDocInfo;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
/**
* Checks references to undefined properties of global variables.
*
* @author nicksantos@google.com (Nick Santos)
*/
class CheckGlobalNames implements CompilerPass {
private final AbstractCompiler compiler;
private final CheckLevel level;
private GlobalNamespace namespace = null;
// Warnings
static final DiagnosticType UNDEFINED_NAME_WARNING = DiagnosticType.warning(
"JSC_UNDEFINED_NAME",
"{0} is never defined");
static final DiagnosticType NAME_DEFINED_LATE_WARNING =
DiagnosticType.warning(
"JSC_NAME_DEFINED_LATE",
"{0} defined before its owner. {1} is defined at {2}:{3}");
static final DiagnosticType STRICT_MODULE_DEP_QNAME =
DiagnosticType.disabled(
"JSC_STRICT_MODULE_DEP_QNAME",
"module {0} cannot reference {2}, defined in " +
"module {1}");
/**
* Creates a pass to check global name references at the given warning level.
*/
CheckGlobalNames(AbstractCompiler compiler, CheckLevel level) {
this.compiler = compiler;
this.level = level;
}
/**
* Injects a pre-computed global namespace, so that the same namespace
* can be re-used for multiple check passes. Returns this for easy chaining.
*/
CheckGlobalNames injectNamespace(GlobalNamespace namespace) {
this.namespace = namespace;
return this;
}
@Override
public void process(Node externs, Node root) {
// TODO(nicksantos): Let CollapseProperties and CheckGlobalNames
// share a namespace.
if (namespace == null) {
namespace = new GlobalNamespace(compiler, root);
}
for (Name name : namespace.getNameForest()) {
checkDescendantNames(name, name.globalSets + name.localSets > 0);
}
}
/**
* Checks to make sure all the descendants of a name are defined if they
* are referenced.
*
* @param name A global name.
* @param nameIsDefined If true, {@code name} is defined. Otherwise, it's
* undefined, and any references to descendant names should emit warnings.
*/
private void checkDescendantNames(Name name, boolean nameIsDefined) {
if (name.props != null) {
for (Name prop : name.props) {
// if the ancestor of a property is not defined, then we should emit
// warnings for all references to the property.
boolean propIsDefined = false;
if (nameIsDefined) {
// if the ancestor of a property is defined, then let's check that
// the property is also explicitly defined if it needs to be.
propIsDefined = (!propertyMustBeInitializedByFullName(prop) ||
prop.globalSets + prop.localSets > 0);
}
validateName(prop, propIsDefined);
checkDescendantNames(prop, propIsDefined);
}
}
}
private void validateName(Name name, boolean isDefined) {
// If the name is not defined, emit warnings for each reference. While
// we're looking through each reference, check all the module dependencies.
Ref declaration = name.getDeclaration();
Name parent = name.parent;
boolean singleGlobalParentDecl =
parent != null &&
parent.getDeclaration() != null &&
parent.localSets == 0;
JSModuleGraph moduleGraph = compiler.getModuleGraph();
for (Ref ref : name.getRefs()) {
if (!isDefined && !isTypedef(ref)) {
reportRefToUndefinedName(name, ref);
} else if (declaration != null &&
ref.getModule() != declaration.getModule() &&
!moduleGraph.dependsOn(
ref.getModule(), declaration.getModule())) {
reportBadModuleReference(name, ref);
} else if (ref.scope.isGlobal() &&
singleGlobalParentDecl &&
parent.getDeclaration().preOrderIndex > ref.preOrderIndex) {
compiler.report(
JSError.make(ref.source.getName(), ref.node,
NAME_DEFINED_LATE_WARNING,
name.getFullName(),
parent.getFullName(),
parent.getDeclaration().source.getName(),
String.valueOf(parent.getDeclaration().node.getLineno())));
}
}
}
private boolean isTypedef(Ref ref) {
// If this is an annotated EXPR-GET, don't do anything.
Node parent = ref.node.getParent();
if (parent.getType() == Token.EXPR_RESULT) {
JSDocInfo info = ref.node.getJSDocInfo();
if (info != null && info.hasTypedefType()) {
return true;
}
}
return false;
}
private void reportBadModuleReference(Name name, Ref ref) {
compiler.report(
JSError.make(ref.source.getName(), ref.node, STRICT_MODULE_DEP_QNAME,
ref.getModule().getName(),
name.getDeclaration().getModule().getName(),
name.getFullName()));
}
private void reportRefToUndefinedName(Name name, Ref ref) {
// grab the highest undefined ancestor to output in the warning message.
while (name.parent != null &&
name.parent.globalSets + name.parent.localSets == 0) {
name = name.parent;
}
compiler.report(
JSError.make(ref.getSourceName(), ref.node, level,
UNDEFINED_NAME_WARNING, name.getFullName()));
}
/**
* Checks whether the given name is a property, and whether that property
* must be initialized with its full qualified name.
*/
private static boolean propertyMustBeInitializedByFullName(Name name) {
// If an object literal in the global namespace is never aliased,
// then all of its properties must be defined using its full qualified
// name. This implies that its properties must all be in the global
// namespace as well.
//
// The same is not true for FUNCTION and OTHER types, because their
// implicit prototypes have properties that are not captured by the global
// namespace.
return name.parent != null && name.parent.aliasingGets == 0 &&
name.parent.type == Name.Type.OBJECTLIT;
}
}