/**
* Declares global variables to serve as aliases for the values in an object literal, optionally
* removing all of the object literal's keys and values.
*
* @param alias The object literal's flattened name (e.g. "a$b$c")
* @param objlit The OBJLIT node
* @param varNode The VAR node to which new global variables should be added as children
* @param nameToAddAfter The child of {@code varNode} after which new variables should be added
* (may be null)
* @param varParent {@code varNode}'s parent
* @return The number of variables added
*/
private int declareVarsForObjLitValues(
Name objlitName,
String alias,
Node objlit,
Node varNode,
Node nameToAddAfter,
Node varParent) {
int numVars = 0;
int arbitraryNameCounter = 0;
boolean discardKeys = !objlitName.shouldKeepKeys();
for (Node key = objlit.getFirstChild(), nextKey; key != null; key = nextKey) {
Node value = key.getFirstChild();
nextKey = key.getNext();
// A get or a set can not be rewritten as a VAR.
if (key.isGetterDef() || key.isSetterDef()) {
continue;
}
// We generate arbitrary names for keys that aren't valid JavaScript
// identifiers, since those keys are never referenced. (If they were,
// this object literal's child names wouldn't be collapsible.) The only
// reason that we don't eliminate them entirely is the off chance that
// their values are expressions that have side effects.
boolean isJsIdentifier = !key.isNumber() && TokenStream.isJSIdentifier(key.getString());
String propName = isJsIdentifier ? key.getString() : String.valueOf(++arbitraryNameCounter);
// If the name cannot be collapsed, skip it.
String qName = objlitName.getFullName() + '.' + propName;
Name p = nameMap.get(qName);
if (p != null && !p.canCollapse()) {
continue;
}
String propAlias = appendPropForAlias(alias, propName);
Node refNode = null;
if (discardKeys) {
objlit.removeChild(key);
value.detachFromParent();
} else {
// Substitute a reference for the value.
refNode = IR.name(propAlias);
if (key.getBooleanProp(Node.IS_CONSTANT_NAME)) {
refNode.putBooleanProp(Node.IS_CONSTANT_NAME, true);
}
key.replaceChild(value, refNode);
}
// Declare the collapsed name as a variable with the original value.
Node nameNode = IR.name(propAlias);
nameNode.addChildToFront(value);
if (key.getBooleanProp(Node.IS_CONSTANT_NAME)) {
nameNode.putBooleanProp(Node.IS_CONSTANT_NAME, true);
}
Node newVar = IR.var(nameNode).useSourceInfoIfMissingFromForTree(key);
if (nameToAddAfter != null) {
varParent.addChildAfter(newVar, nameToAddAfter);
} else {
varParent.addChildBefore(newVar, varNode);
}
compiler.reportCodeChange();
nameToAddAfter = newVar;
// Update the global name's node ancestry if it hasn't already been
// done. (Duplicate keys in an object literal can bring us here twice
// for the same global name.)
if (isJsIdentifier && p != null) {
if (!discardKeys) {
Ref newAlias = p.getDeclaration().cloneAndReclassify(Ref.Type.ALIASING_GET);
newAlias.node = refNode;
p.addRef(newAlias);
}
p.getDeclaration().node = nameNode;
if (value.isFunction()) {
checkForHosedThisReferences(value, key.getJSDocInfo(), p);
}
}
numVars++;
}
return numVars;
}
