SystemVerilog allows to use the `super` keyword to access properties and
methods of a base class. This is useful if there is for example an
identifier with the same name in the current class as in the base class and
the code wants to access the base class identifier.
To support this a bit of refactoring is required. Currently properties are
internally referenced by name, this does not work if there are multiple
properties of the same. Instead reference properties always by index.
In addition when looking up an identifier that resolves to an object return
both the type and the object itself. This is necessary since both `this`
and `super` resolve to the same object, but each with a different type.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The PEIdent elaborate_expr() and elaborate_lval() are sort of open-coding
the path traversal implemented by the new symbol_search() using the old
symbol_search().
Switch them over to use the new symbol search as it is better at handling
the corner cases and is also less code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Assigning a value to a static class property in a class task or function
will currently not write to the static signal, but instead to an otherwise
invisible per instance property. E.g. the example below will print 0 when
the task `t` is called.
```
class C;
static int i;
task t;
i = 10;
$display(i);
end
endclass
```
Since static class properties are implemented as normal signals just
fallback to the default signal handling when an assignment to a static
class property is detected.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
(replacing assertions)
The IEEE standard either requires out-of-bounds bits to be ignored on
write, returned as 1'bx on read, or requires a compile-time error message.
The latter is easier to implement.
When doing continuous assignment of packed structs, support the case
where the value being assigned is a member of a member, etc. Procedural
assignments already support this.
See issue#307
This.new is not allowed.
super.new beyond the first statement is not allowed.
And while I'm at it, clean up the use of "@" and "#" in
the code as tokens for this and super.
An out-of-range constant bit select on the LHS of an assignment was being
treated as an error, whereas an out-of range constant part select would
only result in a warning. In any other context, either case would result
in a warning, so convert the error to a warning.
In addition, all warnings for out-of-range or undefined constant bit/part
selects should be controlled by -Wselect-range.
A compressed assignment statement should give exactly the same
result as the equivalent uncompressed statement. This means
that the type (signed/unsigned) of the LHS affects the type of
the RHS expression (unlike in normal assignments). We need to
take care that bit/part selects and concatenations are correctly
identified as unsigned values, even in the cases where they
reduce to a single whole signal.
If the l-value is an unresolved wire, then elaboration can allow
the assignment as long as it is to bits that are not otherwise
driven. Handle this in some simple cases.
This gets nested l-values to (but just short of) the ivl_target API.
Now the elaborator can process nested l-values, but I haven't figured
out how to present that at the ivl_target.h API.
Static properties are like variables in a named scope.
Detect these variables during elaboration so that the
code generator just sees them as variables.
This implementation works by detecting assignments
to constant properties in elaboration. Allow initializer
assignments to assign to the constant, error all other
assignments, and otherwise treat the constant like any
other property.
Lars-Peter Clausen
Martin Whitaker
Cary R
Stephen Williams
Larry Doolittle