Give hint when user forgets to return `Module` from `elaborate`. #33

cr1901 · 2019-01-29T14:14:20Z

Multiple times, I have forgotten to return a Module from elaborate, and I've found the resulting error to be unhelpful (even though I realize what it means now). The following traceback is the alu.py example with line 23 commented out:

$ python3 alu.py generate
Traceback (most recent call last):
  File "alu.py", line 28, in <module>
    main(alu, ports=[alu.sel, alu.a, alu.b, alu.o, alu.co])
  File "C:\msys64\home\william\src\nmigen\nmigen\cli.py", line 76, in main
    main_runner(parser, parser.parse_args(), *args, **kwargs)
  File "C:\msys64\home\william\src\nmigen\nmigen\cli.py", line 46, in main_runner
    fragment = Fragment.get(design, platform)
  File "C:\msys64\home\william\src\nmigen\nmigen\hdl\ir.py", line 23, in get
    return Fragment.get(obj.elaborate(platform), platform)
  File "C:\msys64\home\william\src\nmigen\nmigen\hdl\ir.py", line 22, in get
    return Fragment.get(obj.get_fragment(platform), platform)
AttributeError: 'NoneType' object has no attribute 'get_fragment'

With this PR, I have added code to give a hint to users what the problem is likely to be. The traceback is changed to the following:

$ python3 alu.py generate
Traceback (most recent call last):
  File "alu.py", line 28, in <module>
    main(alu, ports=[alu.sel, alu.a, alu.b, alu.o, alu.co])
  File "C:\msys64\home\william\src\nmigen\nmigen\cli.py", line 76, in main
    main_runner(parser, parser.parse_args(), *args, **kwargs)
  File "C:\msys64\home\william\src\nmigen\nmigen\cli.py", line 46, in main_runner
    fragment = Fragment.get(design, platform)
  File "C:\msys64\home\william\src\nmigen\nmigen\hdl\ir.py", line 27, in get
    return Fragment.get(obj.elaborate(platform), platform)
  File "C:\msys64\home\william\src\nmigen\nmigen\hdl\ir.py", line 25, in get
    .format(type(obj).__name__))
AttributeError: 'NoneType' object has no attribute 'elaborate' or 'get_fragment'. Did you remember to return a Module object from each user-defined 'elaborate' or 'get_fragment' method?

codecov · 2019-01-29T14:22:12Z

Codecov Report

Merging #33 into master will increase coverage by <.01%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
+ Coverage   85.51%   85.52%   +<.01%     
==========================================
  Files          27       27              
  Lines        3915     3917       +2     
  Branches      764      765       +1     
==========================================
+ Hits         3348     3350       +2     
  Misses        478      478              
  Partials       89       89

Impacted Files	Coverage Δ
nmigen/hdl/ir.py	`96.93% <50%> (+0.02%)`	⬆️

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whitequark · 2019-01-29T14:23:28Z

Tests should never be in different commits, in general.

whitequark · 2019-02-14T20:53:47Z

Implemented this in a slightly more idiomatic way in 8ee6bd8.

hdl.ir: Give hint on AttributeError within Fragment.get().

fd91e21

cr1901 force-pushed the elaborate-msg branch from 1b25c97 to fd91e21 Compare January 29, 2019 14:32

whitequark closed this Feb 14, 2019

nmigen-issue-migration mentioned this pull request Jan 27, 2020

Give hint when user forgets to return Module from elaborate. amaranth-lang/amaranth#39

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Give hint when user forgets to return `Module` from `elaborate`. #33

Give hint when user forgets to return `Module` from `elaborate`. #33

cr1901 commented Jan 29, 2019

codecov bot commented Jan 29, 2019 •

edited

whitequark commented Jan 29, 2019

whitequark commented Feb 14, 2019

Give hint when user forgets to return Module from elaborate. #33

Give hint when user forgets to return Module from elaborate. #33

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cr1901 commented Jan 29, 2019

codecov bot commented Jan 29, 2019 • edited

Codecov Report

whitequark commented Jan 29, 2019

whitequark commented Feb 14, 2019

Give hint when user forgets to return `Module` from `elaborate`. #33

Give hint when user forgets to return `Module` from `elaborate`. #33

codecov bot commented Jan 29, 2019 •

edited