GTKWave needs to have escaped identifiers properly escaped (preceded
with a back slash) in its VCD input. Without this the name may not
display correctly. Even though it is not required, to keep things
consistent LXT and LXT2 formats also prefix escaped identifiers with
a back slash.
This patch adds marks at simulation end if needed and enabled (on
and not over the limit) for vcd/lxt/lxt2 files. End of simulation
callbacks also now have the correct simulation time. The default
file names for lxt and lxt2 now match the vcd file except for the
extension. lx2 is also an alias for lxt2 and the default lxt2 file
extension is lx2. This matches what GTKWave expects. Any lxt2
diagnostic output print LXT2 instead of LXT to make it clear which
dumper you are using.
The attached patch add an implementation for $dumplimit(). It does
not do a hard limit to the file size, but for VCD files it completes
the current time step and puts a comment in the file. For lxt and
lxt2 files the functionality is in place, but because of buffering
the file can be slightly larger than expected.