Static properties are like variables in a named scope.
Detect these variables during elaboration so that the
code generator just sees them as variables.
This implementation works by detecting assignments
to constant properties in elaboration. Allow initializer
assignments to assign to the constant, error all other
assignments, and otherwise treat the constant like any
other property.
Class types that have both implicit construction and
an explicit constructor can blend the implicit and
explicit construction into the "new" function defined
by the user. This doesn't change the behavior any, but
removes a function call and related scope.
The actual signal code is trivial, but the emit expression code needed
to be enhanced to pass a flag that says if one of the arguments in a
binary (except the shifts) or ternary (excluding the condition) context
is unsigned. This information is used to prevent emitting an explicit
$unsigned() for a signal that is used in this context since it will be
implicitly cast to unsigned.
This patch adds support for finding and adding $signed() and $unsigned()
to procedural expressions for the binary, unary and concatenation
operators. Selects have partial support. The select implementation
uncovered limitations in the compiler that need to be fixed before they
will work 100%. Most of the limitations currently generate a message
about the issue.
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.
If constant functions are exited by a return/disable, fix
the leaked "disable" flag that causes blocks in the next
try at the function to not work.
There are also a lot of debug messages added to help find
this and similar problems.
The VHDL to_unsigned function with to arguments is best handled
in the ivl elaborator, so have it generate an $ivlh_to_unsigned
function call in the vhdlpp code, and implement it in the ivl
core.
Also, implement the 'length attribute as a $bits() call for
similar reasons.
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.
Cary R
Stephen Williams
Martin Whitaker