When generate schems and instance arrays are nested, it takes
multiple iterations of elaborate scope, defparams and evaluate
parameters before everything is worked out. Rework the work item
processing so that the loop elaborates scopes and runs defparams
in phases. The phases are needed so that we can tell when the
remaining defparams are orphaned.
Modules mentioned within generate schemes are not candidates for
defaults guesses at root modules. They are, obviously, used within
the generate schem.
We must run generate schemes after running defparams because the
defparams may define the results of the generate schemes. So put
the generate schemes for a module scope into elaborator work items.
The l-value of a defparam assignment is a hierarchical name that may
include array selects to select scopes from module arrays. Therefore
it makes no sense to store parsed defparams in a map. Instead, they
should go into an ordered list. This also maked more sense because later
defparams *may* have the same name as a previous defparam, and will
override the previous defparam. So replace the map of parsed defparams
with a list of parsed defparams.
Also, as soon as the defparam expression is elaborated, the list entry
is no longer needed, so delete it. Save memory.
It is possible for defparams to not find their target the first time
around, because the elaboration of the target scope is not yet done.
So retry the defparams once for each scope by putting it on a work
item in the elaborator_work_items list.
The file and line number information needs to be copied when
doing a macro expansion. This prevents a macro that expands to
an `ifdef of other construct that needs to push the stack
from core dumping.
When we detect that a module instance is an array of instances, delay
the elaboration of the array until after the first defparam processing
is complete. This allows for defparam statements to control the
instantiation of module instance arrays.
Putting scope elaboration into work queue items allows for handling
more complex processing order. The elaboration_work_list queue drives
the processing of elaborate_scope and parameter evaluation.
Nick Gasson
Stephen Williams
Cary R
Larry Doolittle