We need to elaborate expressions so that function calls in
expressions (i.e. ranges) get bound to their proper scope.
This binding is in turn used to emit package scopes. This
is particularly interesting for ports of entities.
The package emit of types and constants needs to know which names are
from the current type and which are imported from libraries. Rework
the scope handling of those names so that the information is preserved.
This patch introduces in ScopeBase separate containers
for declarations coming from the current scope and from
the previous scopes.
Until now, in one scope, all objects were kept in an stl map.
When a scope was created inside other scopes, a shallow
copy of the map was made. This solution was nice for
name shadowing (in new scopes, when a name was
encountered, the old objects were overridden by a new
one), but didn't allow for distinguishing where the objects
were allocated. As a result, it is impossible to know who
the owner is and who should delete them.
In this commit ScopeBase gets two containers: for old
and new objects. If a ScopeBase is made from another
ScopeBase object, all objects from the copied object
go to an old_XXX container, where XXX depends on the
type of the copied objects. When a ScopeBase object
is deleted, the objects from new_XXX are deleted and
the ones from old_XXX are not touched.
This patch adds some complexity to the internals
of ScopeBase, but leaves its interface unchanged.
Entity output ports may be used as l-values in a process within
the bound architecture. Detect that case during elaboration and
adjust the signal declaration so that it works in the Verilog pass.
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.
Maciej Suminski
Cary R
Stephen Williams
Arun Persaud
Pawel Szostek