Named libraries are similar to the work library, but they are not
written to implicitly, or imported implicitly. They are only brought
in by a "library" clause, the the packages within the library are
brought in by a "use" clause.
When a "use" clause tries to pull a package from the work library,
put together a file name and try to find that package in the
work library directory. If found, parse the package file and
try again to find the package.
Bison and Flex generate different interfaces for reentrant
parsers, so handle that different API. We need this change
because library support is going to reuse the parser to
read in library packages.
Also include support for "sorry" messages so that we have a place
to hang unsupported but properly parsed constructs.
In the process of doing this, I also encountered and add parser support
for indexed names. And matching "sorry" messages.
Add enough rules to parse a simple VHDL program:
Parse library and use clauses,
Parse entity declarations, and
Parse architecture bodies.
Add some parser infrastructure:
Handle syntax errors with useful error messages,
Include file name and line numbers in parse errors,
Add some parser debug aids.
Larry Doolittle
Stephen Williams