Entity output ports may be used as l-values in a process within
the bound architecture. Detect that case during elaboration and
adjust the signal declaration so that it works in the Verilog pass.
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.
There has been added additional default attribute to
all 'dump' function calls which is in all cases equal
to 0. Now one can specify how much this debug dumping should
be intended. This should allow people to dump smoothly whole
designs (as it was now) as far as separate units.
This is now the parent who specifies the base indentation
for all components (children). For example, architecture
"decides" how much their signals should be indented.
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.
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.
Separate elaboration from code generation in the Entity, and add
to Architectures a code generator to handle some simple cases. At
this point we have the basic structure for the VHDL compiler.
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.
Stephen Williams
Pawel Szostek
Pawel Szostek
Larry Doolittle