/*
* When naming an anonymous function, the process works loosely by walking
* up the AST and then translating that to a string. The stringification
* happens from some far-up assignment and then going back down the parse
* tree to the function definition point.
*
* This function will walk up the parse tree, gathering relevant nodes used
* for naming, and return the assignment node if there is one. The provided
* array and size will be filled in, and the returned node could be NULL if
* no assignment is found. The first element of the array will be the
* innermost node relevant to naming, and the last element will be the
* outermost node.
*/
ParseNode *gatherNameable(ParseNode **nameable, size_t *size) {
*size = 0;
for (int pos = nparents - 1; pos >= 0; pos--) {
ParseNode *cur = parents[pos];
if (cur->isAssignment())
return cur;
switch (cur->getKind()) {
case PNK_NAME: return cur; /* found the initialized declaration */
case PNK_FUNCTION: return NULL; /* won't find an assignment or declaration */
case PNK_RETURN:
/*
* Normally the relevant parent of a node is its direct parent, but
* sometimes with code like:
*
* var foo = (function() { return function() {}; })();
*
* the outer function is just a helper to create a scope for the
* returned function. Hence the name of the returned function should
* actually be 'foo'. This loop sees if the current node is a
* PNK_RETURN, and if there is a direct function call we skip to
* that.
*/
for (int tmp = pos - 1; tmp > 0; tmp--) {
if (isDirectCall(tmp, cur)) {
pos = tmp;
break;
} else if (call(cur)) {
/* Don't skip too high in the tree */
break;
}
cur = parents[tmp];
}
break;
case PNK_COLON:
/*
* If this is a PNK_COLON, but our parent is not a PNK_OBJECT,
* then this is a label and we're done naming. Otherwise we
* record the PNK_COLON but skip the PNK_OBJECT so we're not
* flagged as a contributor.
*/
if (pos == 0 || !parents[pos - 1]->isKind(PNK_OBJECT))
return NULL;
pos--;
/* fallthrough */
/* Save any other nodes we encounter on the way up. */
default:
JS_ASSERT(*size < MaxParents);
nameable[(*size)++] = cur;
break;
}
}
return NULL;
}
/*
* Resolve the name of a function. If the function already has a name
* listed, then it is skipped. Otherwise an intelligent name is guessed to
* assign to the function's displayAtom field
*/
JSAtom *resolveFun(ParseNode *pn, HandleAtom prefix) {
JS_ASSERT(pn != NULL && pn->isKind(PNK_FUNCTION));
RootedFunction fun(cx, pn->pn_funbox->function());
StringBuffer buf(cx);
this->buf = &buf;
/* If the function already has a name, use that */
if (fun->displayAtom() != NULL) {
if (prefix == NULL)
return fun->displayAtom();
if (!buf.append(prefix) ||
!buf.append("/") ||
!buf.append(fun->displayAtom()))
return NULL;
return buf.finishAtom();
}
/* If a prefix is specified, then it is a form of namespace */
if (prefix != NULL && (!buf.append(prefix) || !buf.append("/")))
return NULL;
/* Gather all nodes relevant to naming */
ParseNode *toName[MaxParents];
size_t size;
ParseNode *assignment = gatherNameable(toName, &size);
/* If the function is assigned to something, then that is very relevant */
if (assignment) {
if (assignment->isAssignment())
assignment = assignment->pn_left;
if (!nameExpression(assignment))
return NULL;
}
/*
* Other than the actual assignment, other relevant nodes to naming are
* those in object initializers and then particular nodes marking a
* contribution.
*/
for (int pos = size - 1; pos >= 0; pos--) {
ParseNode *node = toName[pos];
if (node->isKind(PNK_COLON)) {
ParseNode *left = node->pn_left;
if (left->isKind(PNK_NAME) || left->isKind(PNK_STRING)) {
if (!appendPropertyReference(left->pn_atom))
return NULL;
} else if (left->isKind(PNK_NUMBER)) {
if (!appendNumericPropertyReference(left->pn_dval))
return NULL;
}
} else {
/*
* Don't have consecutive '<' characters, and also don't start
* with a '<' character.
*/
if (!buf.empty() && *(buf.end() - 1) != '<' && !buf.append("<"))
return NULL;
}
}
/*
* functions which are "genuinely anonymous" but are contained in some
* other namespace are rather considered as "contributing" to the outer
* function, so give them a contribution symbol here.
*/
if (!buf.empty() && *(buf.end() - 1) == '/' && !buf.append("<"))
return NULL;
if (buf.empty())
return NULL;
JSAtom *atom = buf.finishAtom();
if (!atom)
return NULL;
fun->setGuessedAtom(atom);
return atom;
}
