YoWASP
All errors become WASM traps
Thanks for all the hard work making this package available.
I installed only one package with the command pip install yowasp-nextpnr-ice40-8k, on Windows 10 x64, Anaconda Python 3.7 (same result for 3.8). It installs yowasp_nextpnr_ice40_8k-0.0.post2625.dev9-py3-none-any.whl
I then run yowasp-nextpnr-ice40. It prints out the full list of command line options, then prints out the following error message:
File "<my home>\miniconda3\lib\runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "<my home>\miniconda3\lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "<my home>\Miniconda3\Scripts\yowasp-nextpnr-ice40.exe\__main__.py", line 7, in <module>
File "<my home>\miniconda3\lib\site-packages\yowasp_nextpnr_ice40\bin\__init__.py", line 61, in run_nextpnr_ice40
sys.exit(_run_wasm_app("nextpnr-ice40.wasm", argv))
File "<my home>\miniconda3\lib\site-packages\yowasp_nextpnr_ice40\bin\__init__.py", line 34, in _run_wasm_app
app.exports["_start"]()
File "<my home>\miniconda3\lib\site-packages\wasmtime\_func.py", line 115, in __call__
raise Trap.__from_ptr__(trap)
wasmtime._trap.Trap: wasm trap: unreachable
wasm backtrace:
0: 0x168303 - <unknown>!<wasm function 2901>
1: 0x161621 - <unknown>!<wasm function 2823>
2: 0x16164e - <unknown>!<wasm function 2824>
3: 0x15192 - <unknown>!<wasm function 243>
4: 0x14cb5 - <unknown>!<wasm function 234>
5: 0xa2b9e - <unknown>!<wasm function 945>
6: 0xd4aa6 - <unknown>!<wasm function 1051>
7: 0xbd4a - <unknown>!<wasm function 62>
8: 0xd5ce1 - <unknown>!<wasm function 1054>
9: 0x16871d - <unknown>!<wasm function 2908>
10: 0x1687a5 - <unknown>!<wasm function 2910>
11: 0x168308 - <unknown>!<wasm function 2902>
12: 0x1768 - <unknown>!<wasm function 21>
where <my home> represents my windows home folder.
If I run pip install yowasp-nextpnr-ice40-all, then the error no longer occurs.
Ah, sorry, I didn't your comment carefully. That's expected behavior at the moment. Until WASM has support for C++ exceptions, all errors will end up in WASM traps.
The original error is easily worked around, however it seems that yosys/nextpnr often generate C++ exceptions. For example, I ran nmigen's 01_blinky.py example (which required changing "led" to "user_led") and it failed when writing the blif file. Is this expected behaviour?
Yep. Until WASM gets first-class exceptions I'm afraid that's what's going to happen. I tried to get it a bit better where possible, but the amount of hacks I'm willing to add (and the upstream is willing to accept) is limited...
A note for anyone else finding that WASM traps are constantly generated.
In my previous comment, it seemed that C++ exceptions were generated very frequently, and I found that yowasp-nextpnr was unusable from nmigen. This was due to installing nmigen from pip (right now the pip version is ~5 months old).
Once I updated to the git version of nmigen, and now that YoWASP/yosys#1 is fixed, nmigen's blinky example now runs and uploads fine, rather than crashing during the writing of the blif file.
Ah, interesting! I indeed have not tested with nmigen 0.2. Nmigen 0.3 is going to be released soon, so that should not be a problem anymore after that.
This will be fixed when https://github.com/WebAssembly/wasi-sdk/pull/198 is merged and exception handling support lands in wasmtime.