Fix warning in FASM

[vaughnbetz]

Recent CI shows this warning in fasm:

/home/runner/work/vtr-verilog-to-routing/vtr-verilog-to-routing/utils/fasm/src/fasm.cpp:572:24: warning: loop variable ‘param’ creates a copy from type ‘const std::__cxx11::basic_string’ [-Wrange-loop-construct]
572 | for(const auto param : vtr::split(fasm_params_str, "\n")) {
| ^~~~~
/home/runner/work/vtr-verilog-to-routing/vtr-verilog-to-routing/utils/fasm/src/fasm.cpp:572:24: note: use reference type to prevent copying
572 | for(const auto param : vtr::split(fasm_params_str, "\n")) {
| ^~~~~
| &

@duck2 : can you fix this? I think it just needs a ref (&).

[hzeller]

In general, not only using string references, but also using more std::string_view would help avoid a lot of allocating new strings. I see that there are a lot of functions that take a std::string as value parameter and return std::vector<std::string> (e.g. split_fasm_entry()).

(And for fast fasm parsing, I'd like to plug this thing I did a while back https://github.com/hzeller/simple-fasm - feel free to just copy into the project).

[vaughnbetz]

@hzeller: if that new fasm works better I'm happy to see it integrated, but I think you'd have to drive it since I don't have any fasm experts on my team.

[AlexandreSinger]

This warning has been resolved in PR #2535

@vaughnbetz should we close this issue?

[vaughnbetz]

Thanks!