Significant rework of scope management to unify the handling of
types in the ieee library and types/constants/components in packages.
This involved adjusting the parser rules to manage a stack of scopes
and rewriting the IEEE library support to not use global maps for
the loaded types.
This creates the Package class to represent packages, and the
Scope class to represent scopes in general. The library functions
are worked up to support scanning scopes for declarations that are
imported by "use" clauses.
Make sure in a conponent instantiation that the instantiated
component is really declared, and that the ports of the binding
really do match the ports of the declared component. This requires
that we create and save component declarations, and that components
have methods for mapping the ports.
This gets us as far as emiting a component instantiation. Very little
error checking/elaboration is done, so there is room for improvement,
but this is a working stub.
These signals are declared in the architecture and are local to
the module. The Architecture already parsed and stored these signal
declarations, but this patch adds the ability to actually emit these
signals in the generated code.
In the process of doing this, I had to regularize the elaboration
and emit of VTypes, so that it can be used in multiple places, not
just in entity headers (for ports).
I also added support for bit selects of signals. This effected a couple
places in the parser, and expressions in general.
These go into the architecture/block of their scope and will be
used by component instantiations to make sure the bindings are
correct and complete.
Also handle signal declarations. The elaborator will use these
to generate module local variables that are used by the architecture.
Elaboration will need a parse tree for expressions. Create one for
the expression types that are currently supported. Also add rules
and the keywords for all the remaining binary logical operators.
Stephen Williams