Type cast expressions and some function calls are syntactically
identical to array element select, so we can only tell the difference
by looking up the name of the identifier being selected. If it is a
type name, then create an ExpCast instead of an ExpName object.
Also, parse and emit vector part selects.
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.
This is rather a cosmetic change. The patch changes
the container used for stack of scopes from std::list
to std::stack. It suits this particular application
a bit better.
Thanks to valgrind analysis it turned out that
there were objects in the parser that were not being
deleted in a proper way. This patch fixes them all.
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.
Infrastructure for debug and emit of sequential statements in processes.
This does not properly handle the actual semantics of the behavioral
code, but it provides an infrastructure where we can handle all the
tricky elaboration to come.
Get to the point where our sample program parses completely, and
the sequential statements generate SequentialStmt objects and a
process object in the architecture.
Also add a few missing expression types.
Significant rework of scope management to unify the handling of
types in the ieee library and types/constants/components in packages.
This involved adjusting the parser rules to manage a stack of scopes
and rewriting the IEEE library support to not use global maps for
the loaded types.
This creates the Package class to represent packages, and the
Scope class to represent scopes in general. The library functions
are worked up to support scanning scopes for declarations that are
imported by "use" clauses.
Make sure in a conponent instantiation that the instantiated
component is really declared, and that the ports of the binding
really do match the ports of the declared component. This requires
that we create and save component declarations, and that components
have methods for mapping the ports.
This gets us as far as emiting a component instantiation. Very little
error checking/elaboration is done, so there is room for improvement,
but this is a working stub.
Up till now only "global" use clauses were parsed
and as a result libraries were loaded.
Since use clauses can appear not only in global context,
parsing of non-global clauses has been introduced and
selected names are now handled (like name1.name2.name3).
These signals are declared in the architecture and are local to
the module. The Architecture already parsed and stored these signal
declarations, but this patch adds the ability to actually emit these
signals in the generated code.
In the process of doing this, I had to regularize the elaboration
and emit of VTypes, so that it can be used in multiple places, not
just in entity headers (for ports).
I also added support for bit selects of signals. This effected a couple
places in the parser, and expressions in general.
The bison grammar has been extended in order
to parse configuration statements. Parsing
remains very primitive but principal constructs
can be now recognized.
These go into the architecture/block of their scope and will be
used by component instantiations to make sure the bindings are
correct and complete.
Also handle signal declarations. The elaborator will use these
to generate module local variables that are used by the architecture.
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.
Implement the parser infrastructure for handling library use clauses,
and use that to handle specific packages of the ieee library. Make
the numeric types come from the numeric_* packages instead of being
built in.
There are internal types that are unbounded arrays. Allow subtype
syntax that creates bounded versions of these arrays, and elaborate
them as vectors at port boundaries. This makes some interesting types
work out.
Also start replacing vhdlint and vhdlreal with int64_t and double,
which are reasonable values for universal_integer and universal_real
from the VHDL standard. I need these cleaned up because the ints in
particular are used for the literal expressions in array index constraints.
Elaboration will need a parse tree for expressions. Create one for
the expression types that are currently supported. Also add rules
and the keywords for all the remaining binary logical operators.
Include the compiler infrastructure to vhdlpp for collecting the
file and line information and attaching it to entities and ports.
Make the parser store the file name during parse.
Create a libmisc library where I can put source files that are
used by multiple programs within the source tree.
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.
Stephen Williams
Cary R
Pawel Szostek
Pawel Szostek