Yosys-Slang Parsing Errors

[loglav03]

@petergrossmann21 I now have yosys-slang set up to be used as a frontend for yosys, and I'm experiencing some errors that I think you would expect from your experience with slang.

I ran ./run_reg_test.py vtr_reg_system_verilog -show_failures and I got the following error below:

This is the section of verilog from vtr_primitives.v (in module duel_port_ram) that I think is tripping up slang:

I believe slang doesn't like it whenever 'always@(posedge clk)' is used or similar rules.

I also noticed the benchmarks you provided that had error/warnings for parsing with slang also had these 'always@(posedge clk)' lines. Is this something that is fixable?

The error is coming from line 3604 in this file from yosys-slang: https://github.com/povik/yosys-slang/blob/master/src/slang_frontend.cc

[loglav03]

I ended up commenting out the UndrivenPass in the file where it was causing it to break, and changed the .tcl file like Amir demonstrated, and that seemed to fix the UndrivenPass failures. I'm going to see if I can comment out that pass on the fly in cmake before it builds since I brought yosys-slang in as a submodule. Thanks @amirarjmand93 and @alirezazd for help on this fix.

I also got it to choose between read_verilog or read_slang based on file extensions when yosys-slang is enabled as a parser.

I'm now testing whether yosys-slang works with multiple input files and it seems to be working in that regard. However, I'm getting some errors within some multi-input .sv files. I'm currently not sure if this is yosys-slang causing these errors or the syntax of the .sv files themselves, or maybe both.

I will probably need some 1-on-1 help with debugging this section @amirarjmand93 @alirezazd @petergrossmann21

[amirarjmand93]

Glad to hear that @loglav03
We have limited .sv files in the vtr repo, and there are some other tests in the slang repo, probably. Maybe this is an issue from the Slang repo. On the other hand, some conflict between the top module and submodels probably raises an error( consider sv tests from known repos). So, if a standalone version of yosys-slang( without VTR) cannot handle multiple files, I suggest opening a PR in the slang group repo and commenting there about the issue. Also, merging all input files into a single top-sub-modules file(.sv) can handle the problem temporarily.

[loglav03]

I found that yosys-slang has a -C command that allows read_slang to read a .txt file containing the names of the input files you want to read together, instead of reading them individually which was causing this issue.