This makes the Verilog backend handle the $connect and $input_port
cells. This represents the undirected $connect cell using the `tran`
primitive, so we also extend the frontend to support this.
Use Bison's typed midrule actions to construct AST_FCALL nodes
with std::unique_ptr, replacing manual 'new' and extra->ast_stack
management. This improves type safety, ensures proper ownership, and
eliminates potential memory leaks.
Ref: https://www.gnu.org/software/bison/manual/html_node/Typed-Midrule-Actions.html
Commit c8e0ac0 introduces a regression on handling case exprs that look
like sva labels. After some debugging, we shouldn't push the identifier
ast node to the ast_stack, otherwise, we will get the following
assertion failure:
```
➜ /tmp yosys -p 'read -sv a1.v'
/----------------------------------------------------------------------------\
| yosys -- Yosys Open SYnthesis Suite |
| Copyright (C) 2012 - 2025 Claire Xenia Wolf <claire@yosyshq.com> |
| Distributed under an ISC-like license, type "license" to see terms |
\----------------------------------------------------------------------------/
Yosys 0.57+1 (git sha1 baa61a146, clang++ 20.1.8 -fPIC -O3)
-- Running command `read -sv a1.v' --
1. Executing Verilog-2005 frontend: a1.v
Parsing SystemVerilog input from `a1.v' to AST representation.
ERROR: Assert `extra->ast_stack.size() == 1' failed in frontends/verilog/verilog_parser.y:709.
➜ /tmp cat a1.v
module test(input wire A);
localparam TEST = 1;
always_comb begin
case (A)
TEST: assert(1);
endcase
end
endmodule
```
We encountered this issue before but with a different error message[^1],
[^1]: https://github.com/YosysHQ/yosys/issues/862
We're currently on version 3.6 of bison at Google, and Yosys
still correctly builds with it. This should better reflect
the actual requirements rather than an overly restrictive
check. If features from 3.8 are required it seems like bumping
would be appropriate.
Signed-off-by: Ethan Mahintorabi <ethanmoon@google.com>
* verilog: fix string literal regular expression.
A backslash was improperly quoted, causing string literal matching
to fail when the final token before a closing quote was an escaped
backslash.
* verilog: add regression test for string literal regex bug.
Test for bug triggered by escaped backslash immediately before
closing quote (introduced in ca7d94af and fixed by 40aa7eaf).
Emil J. Tywoniak
Jannis Harder
Robert O'Callahan
Xing Guo
Michael Kupfer
Ethan Mahintorabi
Gary Wong
garytwong
Krystine Sherwin