Add Python dict support using VUnit dict_t

[ru551n]

Depends on: VUnit/vunit#1229

Motivation

Python code naturally exchanges configuration and results as dicts. VUnit's dict_t (string keys, mixed-type values) is the VHDL counterpart, but the bridge could not pass one in either direction.

API

• eval_dict / call_dict return a new dict_t (aliased as eval / call; no ambiguity with the existing eval/call overloads). The caller owns and deallocates it. Values: int -> integer, float -> real (bit exact), str -> string, bool -> boolean, list of int -> integer_vector_ptr_t ref, nested dict -> nested dict_t ref. None, out-of-range ints, non-str keys and other values are errors; after a reported failure an empty dict is returned. NVC, GHDL and Questa only (Riviera-PRO/Active-HDL report that they require them), like integer_array_t results.
• arg(dict_t) / kwarg(kw, dict_t) write a Python literal {"key": value, ...} using only the public dict_pkg API (num_keys, get_key, get_value_type, getters). Values: integer, real, string, boolean, std_ulogic, integer_vector, real_vector, integer_vector_ptr_t, nested dict. Other types fail like other unconvertible arguments. Text only, so it works on all simulators.

Python side: KIND_DICT and _dict_result in runtime.py serialise the dict into the existing byte-result path (no native changes). The generated python_pkg.vhd is regenerated from the template.

Tests

New cases in tests/tb_python_pkg_bridge.vhd: every value type and nested dicts, exact reals, error cases, arg/kwarg, a round trip VHDL dict -> Python -> VHDL, an unconvertible value, and a group & with a dict kwarg. Full suite: 113 of 113 pass on NVC and on GHDL, pytest tests/test_python_bridge.py 85 passed.

Notes: tests do not deallocate multi-key dicts because new_dict after deallocate of a grown dict fails in VUnit's dict_pkg (recycled pool arrays are longer than requested). Reals are sent as an exact mantissa/exponent because NVC's real'value misparses multi-digit exponents.

🤖 Generated with Claude Code

[ru551n]

Added a test that deallocates returned multi-key dicts. It needs the new_dict fix now included in VUnit/vunit#1229.