ERROR: Assert `n.id != 0' failed - seems related to unassigned variables

Hello,

I am hitting this assertion failure in recent builds of ghdl plugin for yosys.

Line 204 in 45da327

log_assert(n.id != 0);

ERROR: Assert `n.id != 0' failed in frontends/ghdl/ghdl.cc:204.

I am testing using last night's OSS CAD Suite release for linux x64

GHDL 2.0.0-dev (1.0.0.r816.gcd3a3210.dirty) [Dunoon edition]
 Compiled with GNAT Version: 9.3.0
 llvm code generator
Written by Tristan Gingold.

Copyright (C) 2003 - 2021 Tristan Gingold.
GHDL is free software, covered by the GNU General Public License.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Yosys 0.10+14 (git sha1 772b9a108, clang 10.0.0-4ubuntu1 -fPIC -Os)

Steps to replicate:

Unarchive attached zip. cd ghdl_assert_fail into the newly created dir.
Run GHDL+Yosys build

cd verilator; # The build dir inside ghdl_assert_fail 
ghdl -i --std=08 `cat ../vhdl_files.txt`
ghdl -m --std=08 top 
yosys -g -p "ghdl --std=08 top; proc; opt; fsm; opt; memory; opt; write_verilog ../top/top.v"

WRONG FILE PATHS WHOOPS:ghdl_assert_fail.zip

Correct: ghdl_assert_fail_correct_file_paths.zip

I will follow up with the working build I also have to compare to...

The same VHDL code compiles just fine - no assertion failure. With these versions

GHDL 2.0.0-dev (1.0.0.r778.g140ec481) [Dunoon edition]
 Compiled with GNAT Version: 9.3.0
 mcode code generator
Written by Tristan Gingold.

Copyright (C) 2003 - 2021 Tristan Gingold.
GHDL is free software, covered by the GNU General Public License.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Yosys 0.9+4303 (git sha1 e6766b95, clang 10.0.0-4ubuntu1 -fPIC -Os)

This may be related to this issue:
#158

Similar things about adding/removing extra variable assignments seem to change behavior

Whoops didnt fix absolute file paths on my system in the first .zip file - new one coming

ghdl_assert_fail_correct_file_paths.zip

now fixed. Thank you for the issue.

Excellent - finally got around to testing this via the nightly oss cad suite build.

Working great!

Thanks again for your time!

Great to know it works for you.