/**
* Collapses definitions of the collapsible properties of a global name. Recurs on subnames that
* also represent JavaScript objects with collapsible properties.
*
* @param n A node representing a global name
* @param alias The flattened name for {@code n}
*/
private void collapseDeclarationOfNameAndDescendants(Name n, String alias) {
boolean canCollapseChildNames = n.canCollapseUnannotatedChildNames();
// Handle this name first so that nested object literals get unrolled.
if (n.canCollapse()) {
updateObjLitOrFunctionDeclaration(n, alias, canCollapseChildNames);
}
if (n.props == null) {
return;
}
for (Name p : n.props) {
// Recur first so that saved node ancestries are intact when needed.
collapseDeclarationOfNameAndDescendants(p, appendPropForAlias(alias, p.getBaseName()));
if (!p.inExterns
&& canCollapseChildNames
&& p.getDeclaration() != null
&& p.canCollapse()
&& p.getDeclaration().node != null
&& p.getDeclaration().node.getParent() != null
&& p.getDeclaration().node.getParent().isAssign()) {
updateSimpleDeclaration(appendPropForAlias(alias, p.getBaseName()), p, p.getDeclaration());
}
}
}
/**
* Adds global variable "stubs" for any properties of a global name that are only set in a local
* scope or read but never set.
*
* @param n An object representing a global name (e.g. "a", "a.b.c")
* @param alias The flattened name of the object whose properties we are adding stubs for (e.g.
* "a$b$c")
* @param parent The node to which new global variables should be added as children
* @param addAfter The child of after which new variables should be added
* @return The number of variables added
*/
private int addStubsForUndeclaredProperties(Name n, String alias, Node parent, Node addAfter) {
Preconditions.checkState(n.canCollapseUnannotatedChildNames());
Preconditions.checkArgument(NodeUtil.isStatementBlock(parent));
Preconditions.checkNotNull(addAfter);
if (n.props == null) {
return 0;
}
int numStubs = 0;
for (Name p : n.props) {
if (p.needsToBeStubbed()) {
String propAlias = appendPropForAlias(alias, p.getBaseName());
Node nameNode = IR.name(propAlias);
Node newVar = IR.var(nameNode).useSourceInfoIfMissingFromForTree(addAfter);
parent.addChildAfter(newVar, addAfter);
addAfter = newVar;
numStubs++;
compiler.reportCodeChange();
// Determine if this is a constant var by checking the first
// reference to it. Don't check the declaration, as it might be null.
if (p.getRefs().get(0).node.getLastChild().getBooleanProp(Node.IS_CONSTANT_NAME)) {
nameNode.putBooleanProp(Node.IS_CONSTANT_NAME, true);
}
}
}
return numStubs;
}
@Override
public void process(Node externs, Node root) {
GlobalNamespace namespace;
namespace = new GlobalNamespace(compiler, root);
if (inlineAliases) {
inlineAliases(namespace);
}
nameMap = namespace.getNameIndex();
globalNames = namespace.getNameForest();
checkNamespaces();
for (Name name : globalNames) {
flattenReferencesToCollapsibleDescendantNames(name, name.getBaseName());
}
// We collapse property definitions after collapsing property references
// because this step can alter the parse tree above property references,
// invalidating the node ancestry stored with each reference.
for (Name name : globalNames) {
collapseDeclarationOfNameAndDescendants(name, name.getBaseName());
}
}
/**
* Flattens all references to collapsible properties of a global name except their initial
* definitions. Recurs on subnames.
*
* @param n An object representing a global name
* @param alias The flattened name for {@code n}
*/
private void flattenReferencesToCollapsibleDescendantNames(Name n, String alias) {
if (n.props == null || n.isCollapsingExplicitlyDenied()) {
return;
}
for (Name p : n.props) {
String propAlias = appendPropForAlias(alias, p.getBaseName());
if (p.canCollapse()) {
flattenReferencesTo(p, propAlias);
} else if (p.isSimpleStubDeclaration() && !p.isCollapsingExplicitlyDenied()) {
flattenSimpleStubDeclaration(p, propAlias);
}
flattenReferencesToCollapsibleDescendantNames(p, propAlias);
}
}