nsIXPCScriptable flags handling in xpc_map_end.h is a bit of a mess.
- Half the flags relate to whether various functions are defined (PreCreate,
GetProperty, etc). These are set using the XPC_MAP_WANT_* macros;
for each one xpc_map_end.h inserts the corresponding flag using the
preprocessor (see XPC_MAP_CLASSNAME::GetScriptableFlags()).
- The other half of the flags relate to other things (IS_GLOBAL_OBJECT,
DONT_REFLECT_INTERFACE_NAMES, etc). These are set using the XPC_MAP_FLAGS
macro.
Having two similar but different mechanisms to set the flags for a class is
confusing. (Indeed, until recently we had some classes where a single flag was
redundantly specified via both mechanisms.) Note also that the classes done in
dom/base/nsIDOMClassInfo.h also specify all the flags in a single value,
similar to how XPC_MAP_FLAGS works.
This patch removes the XPC_MAP_WANT_* macros. All flags are now set
via XPC_MAP_FLAGS. This is a significant simplification to xpc_map_end.h and
all the places that use it.
The downside of this change is that I had to change the flag constants from
class constants (i.e. nsIXPCScriptable::FOO) to macros (i.e.
NSIXPCSCRIPTABLE_FOO) because they need to be used in #if statements like this
in xpc_map_end.h:
#if !((XPC_MAP_FLAGS) & NSIXPCSCRIPTABLE_WANT_PRECREATE)
and you can't use a '::'-qualified name inside a #if. I think this downside is
outweighed by the simplification described above.
Overall the patch removes 80 lines of code.
