JavaScript:SpiderMonkey:C++ Coding Style
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Basics
The C Coding Style Guidelines apply unless overridden here. If this becomes awkward we should fork and diverge instead of referencing.
The rest of this page is a strawman proposal. Feel free to add, amend, or even correct if something is obviously wrong. Raise issues in the newsgroup.
C++ is powerful, with many degrees of freedom and some attractive nuisances. We should aspire to use it in a lean, close-to-the-metal fashion, and avoid style over substance bikeshedding.
Namespaces
- Instead of JS/js and JS_ prefixing for public function and type names, respectively, use
namespace JS { ... }
- Instead of js_ prefixing for library-private and "friend" functions,
namespace js { ... }
- Other namespaces? Are these names too short and likely to collide?
Classical OOP
- Most structs can become classes, with associated functions becoming methods. This already started for the upvar2 bug.
- Style detailing: mrbkap suggests left brace before class body on its own line in column 1 to match function style and facilitate vim navigation. People do this already when inheriting, since the left brace can get lost in the superclass(es).
class JSObject
{
...
}
- An easy starter bug to steal and patch.
- Most macros become inline helpers. With LiveConnect gone on mozilla-central, we can make the helpers methods of relevant structs or classes finally, instead of static inline functions.
- Based on 20+ years of bad experiences, we are going to go slow and resist virtual methods and bases, MI, and the like. Function pointer tables for now, as before -- see JSObjectOps needs a make-over.
- Templates are good, Mozilla has positive experience and the portability is there for the kind of RAII helpers we need.
- No exceptions, so std is hard to use. Sayrer suggests using v8's vector type to get started.
- We would benefit from better hashtable API. Implementation, in targeted ways (delegate free and removed sentinel representation so that the double hashtable entry can be a word; improve bit-mixing into multiplicative hash if the cycle costs can be supported), but measurement is required and we should understand down to the bits what is going on.