In order to support unsized constants being used as parameters, the `const` struct needs to know if it is unsized (so that the parameter can be used to set the size).
Add unsized flag to param value serialization and rtlil back-/front-end.
Add cell params to `tests/rtlil/everything.v`.
`Const::size()` returns int, so change iterators that use it to `auto` instead of `size_t`.
For cases where size is being explicitly cast to `int`, use the wrapper that we already have instead: `Yosys::GetSize()`.
Instead of passing around in_lvalue/in_param flags to simplify, we make
the flags into properties of the AST nodes themselves. After the tree
is first parsed, we once do
ast->fixup_hierarchy_flags(true)
to walk the full hierarchy and set the flags to their initial correct
values. Then as long as one is using ->clone(), ->cloneInto() and the
AstNode constructor (with children passed to it) to modify the tree, the
flags will be kept in sync automatically. On the other hand if we are
modifying the children list of an existing node, we may need to call
node->fixup_hierarchy_flags()
to do a localized fixup. That fixup will update the flags on the node's
children, and will propagate the change down the tree if necessary.
clone() doesn't always retain the flags of the subtree being cloned. It
will produce a tree with a consistent setting of the flags, but the
root doesn't have in_param/in_lvalue set unless it's intrinsic to the
type of node being cloned (e.g. AST_PARAMETER). cloneInto() will make
sure the cloned subtree has the flags consistent with the new placement
in a hierarchy.
Add asserts to make sure the old and new way of determining the flags
agree.
It's a repeating pattern to print an error message tied to an AST
node. Start using an 'input_error' helper for that. Among other
things this is beneficial in shortening the print lines, which tend
to be long.
When the verilog frontend perfomed constant evaluation of unbased
unsized constants in a context-determined expression it did not properly
extend them by repeating the bit value. This only affected constant
evaluation and not constants that made it through unchanged to RTLIL.
The latter case was already covered by tests and working before.
This fixes the const-eval issue by checking the `is_unsized` flag in
bitsAsConst and extending the value accordingly.
The newly added test also tests the already working non-const-eval case
to highlight that both cases should behave the same.
- Attempt to lookup a derived module if it potentially contains a port
connection with elaboration ambiguities
- Mark the cell if module has not yet been derived
- This can be extended to implement automatic hierarchical port
connections in a future change
