[sv-bc] Re: Special 1364 Meeting to resolve Issue 680 (Configs)

I still see a possible compromise that would allow configs in Verilog
source files while reducing the keyword conflicts caused by some of
the config keywords.

We have added the `begin_keywords directive that "turns off" certain
keywords to match older versions of the language.  We could add an
additional version string that selects the keyword set that is allowed
in Verilog-2001 source files but not in configs or library map files.
This set of keywords would allow compiling almost all Verilog-1995
source files, and all Verilog-2001 files that did not contain configs.
It would be the more backward compatible dialect of Verilog-2001.
There would be another version string that would reserve the same
keywords plus the config and library map file keywords.  A possible
set of version strings would be "1364-2001" and "1364-2001+configs"

The same could be done for Verilog-2005, since it also doesn't have
any problematic keywords except the ones in configs.  However, since
the only difference between 2001 and 2005 is the uwire keyword, we
could probably do without this.

The main goal of having these two keyword sets is not so much that
users will directly use the directives to get them.  After all, if they
are willing to put directives in all their files, they can set the
keywords appropriately for each file.  The goal is to define a dialect
that users can use to compile all their Verilog files (1995 or 2001)
without having to use any directives in them.  This dialect could be
the default of a tool or could be chosen by command line option.  The
`begin_keywords version string is just a way of defining this particular
keyword set in the standard, and ensuring that all implementations
support it.

Steven Sharp
sharp@cadence.com