Review

16

com/google/javascript/jscomp/InlineFunctions.java

checkNameUsage(NodeTraversal, Node, Node)

class InlineFunctions.FindCandidatesReferences {
    /**
     * Find functions that can be inlined.
     */
    private void checkNameUsage(NodeTraversal t, Node n, Node parent) {
      Preconditions.checkState(n.getType() == Token.NAME);

      if (parent.getType() == Token.VAR || parent.getType() == Token.FUNCTION) {
        // This is a declaration.  Duplicate declarations are handle during
        // function candidate gathering.
        return;
      }

      if (parent.getType() == Token.CALL && parent.getFirstChild() == n) {
        // This is a normal reference to the function.
        return;
      }

      // Check for a ".call" to the named function:
      //   CALL
      //     GETPROP/GETELEM
      //       NAME
      //       STRING == "call"
      //     This-Value
      //     Function-parameter-1
      //     ...
      if (NodeUtil.isGet(parent)
           && n == parent.getFirstChild()
           && n.getNext().getType() == Token.STRING
           && n.getNext().getString().equals("call")) {
        Node gramps = n.getAncestor(2);
        if (gramps.getType() == Token.CALL
            && gramps.getFirstChild() == parent) {
          // Yep, a ".call".
          return;
        }
      }

      // Other refs to a function name remove its candidacy for inlining
      String name = n.getString();
      FunctionState fs = fns.get(name);
      if (fs == null) {
        return;
      }

      // If the name is being assigned to it can not be inlined.
      if (parent.getType() == Token.ASSIGN && parent.getFirstChild() == n) {
        // e.g. bar = something; <== we can't inline "bar"
        // so mark the function as uninlinable.
        // TODO(johnlenz): Should we just remove it from fns here?
        fs.setInline(false);
      } else {
        // e.g. var fn = bar; <== we can't inline "bar"
        // As this reference can't be inlined mark the function as
        // unremovable.
        fs.setRemove(false);
      }
    }

}