v2act: namespace support for celllib

[olerichter]

current state:

the v2act -l <celllib.act> <verilog.v> assumes the cell lib to live inside namespace sync or async.

if the cells are in a different namespace they are reported as missing modules.

celllib.act :

namespace sync {
  export defcell INVX1 (bool? A; bool! Y)
  {
    prs {
      A => Y-
    }
  }
}

verilog.v

module blk1(in,out);
  output [1:0] out;
  input [1:0] in;
  
  INVX1 cell1(.A (in[0]), .Y (out[0]));
  INVX1 cell2(.A (in[1]), .Y (out[1]));
endmodule

output:

defproc blk1 (bool? in[2], bool! out[2])
{
   /*--- types ---*/
   INVX1 cell1;
   INVX1 cell2;
  /*--- connections ---*/
   cell1(.A=in[0], .Y=out[0]);
   cell1(.A=in[1], .Y=out[1]);
}

proposed behavior:

v2act -l <celllib.act> [-n namespace::subnamespace] with default to sync/async namespace

namespace::subnamespace can be any namespace hierarchy

namespace <namespace> {
namespace <subnamespace> {
  export defcell INVX1 (bool? A; bool! Y)
  {
    prs {
      A => Y-
    }
  }
}
}

verlig.v same as above

output:

defproc blk1 (bool? in[2], bool! out[2])
{
   /*--- types ---*/
   namespace::subnamespace::INVX1 cell1;
   namespace::subnamespace::INVX1 cell2;
  /*--- connections ---*/
   cell1(.A=in[0], .Y=out[0]);
   cell1(.A=in[1], .Y=out[1]);
}

purely optional (current use case does not need it):

have the ability to define multiple namespaces in which cells sit in.

[rmanohar]

Added -n command line option to v2act in core ACT library to recognize cells in a different namespace. However, at present, the namespace is not appended to the cell types and is assumed to be in the namespace search path.