Greetings Travis An advantage to the design proposed in the initial patch is that the same set of purify flags will be used across invocations. This could be useful to prevent regeneration of the instrumented libraries and other such items, along with possibly providing the ability to add a rule for cleaning up said items. A disadvantage is that it's harder to modify the flags if changes are needed.
One enhancement to the proposed alternate design is to auto-detect the existence of the PURIFYOPTIONS and/or PUREOPTIONS environmental variables, and from the existence deduct that the user wish to perform a purify enabled build (unless specified otherwise, such as with the WITHOUT_PURIFY switch). --Andrew Black
