'NoneType' object has no attribute 'address' maybe when symbol_link is missing

[hsl38]

Hi

I am using the XCPsim.a2l file that comes with CANape of Vector. I tried the "getting started with pyA2L" code with the file. I had 'NoneType' object has no attribute 'address' error. In the hope of locating the cause, I change the code a bit.

for m in measurements:
    try:
        print(f'{'':8} {m.name:48} {m.datatype:12} {m.ecu_address.address:08x} {m.symbol_link_id:4}')
    except Exception as e:
        # print(f'{m.name:48} {m.datatype:12} {m.symbol_link_id:12}', end=' ')
        print(f'{'ERROR':8} {m.name:48} {m.datatype:12} {'':16}Exception: {e}')

The output is as following. It seems to me that the errors occur when symbol_link is missing.

         BitSlice                                         UWORD        001be05c    1
         BitSlice0                                        UWORD        001be05c    2
         BitSlice1                                        UWORD        001be05c    3
         BitSlice2                                        UWORD        001be05d    4
         Counter_B4                                       UBYTE        001bdcb3    6
         Counter_B5                                       UBYTE        001bdcb3    7
         Counter_B6                                       UBYTE        001bdcb3    8
         Counter_B7                                       UBYTE        001bdcb3    9
ERROR    DtChannel1                                       FLOAT32_IEEE                 Exception: 'NoneType' object has no attribute 'address'
         FW1                                              UBYTE        001c00ab   13
         KL1Output                                        UBYTE        001bddd2   23
ERROR    MaxChannel1                                      FLOAT32_IEEE                 Exception: 'NoneType' object has no attribute 'address'
ERROR    MinChannel1                                      FLOAT32_IEEE                 Exception: 'NoneType' object has no attribute 'address'
         PWM                                              UBYTE        001bdddf   31
         PWMFiltered                                      UBYTE        001bdde2   32
         PWM_Level                                        SBYTE        001c00a2   33

--- deleted ---

         byteCounter                                      UBYTE        001bdcb3 1072
         bytePWMFilter                                    UBYTE        001c00a3 1073
         channel1                                         FLOAT32_IEEE 001bd004 1075
         channel2                                         FLOAT32_IEEE 001bd008 1076
         channel3                                         FLOAT32_IEEE 001bd00c 1077
         channel_d                                        FLOAT64_IEEE 001bd028 1078
         counter1000msSignal                              FLOAT64_IEEE 001bd0c8 1079
         counter100msSignal                               FLOAT64_IEEE 001bd0c0 1080
         counter10msSignal                                FLOAT64_IEEE 001bd0b8 1081
         doubleTestParam01                                FLOAT64_IEEE 001bd0d0 1082
         doubleTestParam01_mea                            FLOAT64_IEEE 001bd0d0 1083

I am not sure if it is ok to attach the XCPsim.a2l here. I will try to explain what I found instead.

Searching the a2l file for "DtChannel1" (the 1st error) gave me 4 matches. Two found in MEASUREMENT definition, one in COMPU_METHOD definition, one in GROUP Virtual definition. There was no SYMBOL_LINK property in any of the definitions.

I wish I could fix it myself. Can somebody fix it, please?

My environment

Python: 3.12.5
pyA2L: latest version from pip
OS: Windows 11

Make your day

[christoph2]

@hsl38
The paramters from name to upperLimit are mandatory according the ASAM MCD-2MC specification, the remaining ones - including SYMBOL_LINK - are optional.

Measurement(name = 'ASAM.M.SCALAR.SWORD.IDENTICAL', longIdentifier = 'Scalar measurement', datatype = 'SWORD', conversion = 'CM.IDENTICAL',
    resolution = 0, accuracy = 0.0, lowerLimit = -32268.0, upperLimit = 32267.0, rid = 14,
            
    bit_mask_id = None, byte_order_id = None, discrete = False, display_identifier_id = None,
    ecu_address_extension_id = None, format_id = 6, function_list_id = None, matrix_dim_id = None,
    max_refresh_id = None, phys_unit_id = None, ref_memory_segment_id = None, symbol_link_id = None
)

i.e.: in any case there is a check against None required.
Now we can refer to the element in question(symbol_link) in the pya2ldb model, giving us the two parameters symbolName and offset.

The complete code fragment then looks like this:

for m in measurements:
    if m.symbol_link:
        symlink_name = m.symbol_link.symbolName
        symlink_offset = m.symbol_link.offset
    else:
        symlink_name = ""
        symlink_offset = 0
    print(f'{'':8} {m.name:48} {m.datatype:12} {m.ecu_address.address:08x} symlink_name: {symlink_name:35} symlink_offset: {symlink_offset}')

I short test gives me:

         RTTarget.ModelCalcTime                           A_INT64      00024e40 symlink_name: gCalcTime                           symlink_offset: 0
         RTTarget.ModelExecutionCounter                   ULONG        000aa12c symlink_name: _gRTTarget_ModelExecutionCounter    symlink_offset: 0
         RTTarget.ModelStepTime                           ULONG        000aa128 symlink_name: _gRTTarget_ModelStepExecutionTime   symlink_offset: 0
         TimerTicks                                       A_UINT64     000aa208 symlink_name: gTimerTicks                         symlink_offset: 0

I hope it helps.