Hashability of non-primitive types used as a user-defined-property value.

[eblankenberg-trt]

Attempting to create a user-defined property that references a non-primitive (hashable) value causes the tool to fail. For example, a reference to another field. The current workaround is to describe the reference via a string that is a path which is not ideal. See the example below:

property view_pointer {
    type = field;
    component = field; // TODO field is not hashable so breaks peakrdl-python but for now we do relative directories
};

addrmap test {
    reg {
        field {
            hw = rw;
            sw = rw;
        } value [32-1:0];
    } view;

    reg {
        field {
            hw = rw;
            sw = rw;
        } value [32-1:0];
    } pointer;

    view.value->view_pointer = pointer.value;
};

Calling python -m peakrdl python test.rdl --udp view_pointer -o out yields:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl\__main__.py", line 3, in <module>
    main()
    ~~~~^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl\main.py", line 146, in main
    options.subcommand.main(importers, options)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl\subcommand.py", line 158, in main
    self.do_export(root.top, options)
    ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\__peakrdl__.py", line 179, in do_export    
    peakrdl_exporter.export(
    ~~~~~~~~~~~~~~~~~~~~~~~^
        node=top_node,
        ^^^^^^^^^^^^^^
    ...<19 lines>...
        hashing_method=NodeHashingMethod[options.hashing_mode]
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\exporter.py", line 1094, in export
    self.__export_reg_model(
    ~~~~~~~~~~~~~~~~~~~~~~~^
        top_block=top_block, package=package, asyncoutput=asyncoutput,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<11 lines>...
        hashing_method=hashing_method
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\exporter.py", line 222, in __export_reg_model
    RDLWalker(unroll=True).walk(top_block.parent, unique_component_walker,
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                skip_top=False)
                                ^^^^^^^^^^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\systemrdl\walker.py", line 218, in walk
    self._walk(child, listeners)
    ~~~~~~~~~~^^^^^^^^^^^^^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\systemrdl\walker.py", line 227, in _walk
    self.current_action = self.do_enter(node, listener)
                          ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\systemrdl\walker.py", line 271, in do_enter
    new_action = listener.enter_Addrmap(node) or WalkerAction.Continue
                 ~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\unique_component_iterator.py", line 466, in enter_Addrmap
    return self.__enter_non_field_node(node)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\unique_component_iterator.py", line 430, in __enter_non_field_node
    potential_unique_node = self.__build_peak_rdl_unique_component(node)
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\unique_component_iterator.py", line 378, in __build_peak_rdl_unique_component
    nodal_hash_result = self.calculate_or_lookup_hash(node)
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\unique_component_iterator.py", line 508, in calculate_or_lookup_hash
    nodal_hash_result = node_hash(node=node, udp_include_func=self.udp_include_func,
                                  hide_node_callback=self.hide_node_callback,
                                  include_name_and_desc=self.include_name_and_desc,
                                  method=self.hashing_method)
  File "C:\BLANew\quick_gain\release_test\trt-gain-fpga\.pixi\envs\default\Lib\site-packages\peakrdl_python\systemrdl_node_hashes.py", line 549, in node_hash
    return hash(tuple(hash_content))
TypeError: unhashable type: 'FieldNode'

I think it may be ok for many use-cases if references to objects that don't exist in the Python HAL (ex. signals) exist just as reference objects with the SystemRDL metadata (inst name, properties, etc.).

See #291 for a use case (view register with underlying pointer) for when this may be helpful.

[eblankenberg-trt]

Just like #291 this is a fairly big request. I have a workaround in place, I am moreso raising this issue to gauge if you would be willing to have this in the library. I can create a PR at a later time to implement it.

[krcb197]

@eblankenberg-trt

Thank you for raising this bug. I was unaware that a User Defined Property (UDP) could reference other nodes.

I am concerned that attempting to fix this fully could be a lot of effort for something that might be a rarely used corner case. Therefore, I am considering a two stage approach:

1. An initial fix to remove the bug where the UDP will simply hold the path to the references object, stored as a string (which can be hashed). Anyone who wants to use that string to walk the structure could get to the node needed using the existing get_child_by_system_rdl_name method to tranverse the structure.
2. A full fix where the referenced node is properly cross-linked. This can be put on the issue list for someone who wants to take up the challenge.

Does that approach seem reasonable

[eblankenberg-trt]

That seems fine, I can implement the fix myself at a later date but I am expecting my current deliverables to keep me fully occupied for at least the next two to three weeks (including weekends). Don't feel rushed to work on this, I could even implement the intermediate fix you described if you are otherwise occupied.

[krcb197]

@eblankenberg-trt I have taken a look at this today.
I have implemented a prototype of the string version and also include the code to reverse the tree using the get_child_by_system_rdl_name within the base class so that it resolves the references at runtime. Take a look at the 3.1.0rc2 prerelease and let me know if this works. It needs a bit more work to build at the test case to cover all the permutations before making a full release. In particular, I am not sure the dereferencing works with all types of array at the moment.

[eblankenberg-trt]

Thank you for implementing this so quickly, I will follow up as soon as possible, probably later this week or early next week.

[krcb197]

@eblankenberg-trt

I have done some more testing and introduced a fix to cross-referencing array nodes. See the 3.1.0rc3 pre-release.