defparam assignments found inside a generate block were being stored
in the enclosing module scope. They should be stored in the generate
block scope.
Also removed the genvar list from the PGenerate class, as this is
already declared in the base LexicalScope class.
When checking for name collisions, the compiler looks for genvar
declarations in the enclosing module rather than in the current
scope, which leads to false positives. The compiler also places
all genvar declarations in the enclosing module scope, even when
the declarations are inside a generate block which has its own
scope. This patch fixes both these faults. It also fixes some
typos and outdated information in comments.
Verilog generate schemes support a special case where conditional
generate schemes that contain only a nested conditional generate
scheme do not create a new scope. Instead, it relies on the nested
generate scheme to generate the scope.
Currently, parameters and localparams declared in tasks, functions,
generate blocks, and named blocks are placed in the parent module
scope. Event declarations in these scopes are not permitted (a
syntax error is reported). This patch corrects this behaviour, so
that all the above declarations are accepted and are placed in the
scope in which they are declared.
Note that the IEEE standard does not permit parameter declarations
in generate blocks. This patch causes the parser to reject such
declarations.
Within generate schemes it is possible to have nested scopes, even
more liberally then outside generate blocks. So see to it that the
scopes properly stack with the generate blocks, and that wires and
behaviors are put in the right scopes.
Generating task/function definitions involves getting the functions
to put themselves into the generate scheme instead of the module,
and getting elaboration to elaborate those definitions in the
generate scheme.
Named begin/end blocks burried within generate schemes need to be
elaborated. Handle this by remembering to elaborate_scope on the
statements within the generate scheme.
In the process, clean up/regularize some of the member names and
methods.
Move the storage of wires (signals) out of the Module class into
the PScope base class, and instead of putting the PWires all into
the Module object, distribute them into the various lexical scopes
(derived from PScope) so that the wire names do not need to carry
scope information.
This required some rewiring of elaboration of signals, and rewriting
of lexical scope handling.
Generate case is a complex generate scheme where the items are
sub-schemes of the case generate itself. The parser handles them
something like nested generate statements, but storing the case
guards as the test expression. Then the elaborator notes the
case scheme and reaches into the case item schemes inside to make
up tests, select the generate item, and elaborate.