PyHDI/Pyverilog

Unsized numbers without base not supported

Louis-DR opened this issue · 2 comments

Hello,

I noticed that unsized literal number constants with the base specified ('d0) are supported but if the base is not specified ('d) it raises a ParseError exception :

module top (
  output [7:0] q
);

assign q = '0;

endmodule
>>> python3 examples/example_parser.py top.v
Generating LALR tables
WARNING: 183 shift/reduce conflicts
Traceback (most recent call last):
  File "/Users/louis/Workspace/Pyverilog/examples/example_parser.py", line 55, in <module>
    main()
  File "/Users/louis/Workspace/Pyverilog/examples/example_parser.py", line 45, in main
    ast, directives = parse(filelist,
                      ^^^^^^^^^^^^^^^
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/parser.py", line 2371, in parse
    ast = codeparser.parse()
          ^^^^^^^^^^^^^^^^^^
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/parser.py", line 2349, in parse
    ast = self.parser.parse(text, debug=debug)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/parser.py", line 77, in parse
    return self.parser.parse(text, lexer=self.lexer, debug=debug)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/ply/yacc.py", line 333, in parse
    return self.parseopt_notrack(input, lexer, debug, tracking, tokenfunc)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/ply/yacc.py", line 1063, in parseopt_notrack
    lookahead = get_token()     # Get the next token
                ^^^^^^^^^^^
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/lexer.py", line 51, in token
    return self.lexer.token()
           ^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/ply/lex.py", line 386, in token
    newtok = self.lexerrorf(tok)
             ^^^^^^^^^^^^^^^^^^^
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/lexer.py", line 259, in t_error
    self._error(msg, t)
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/lexer.py", line 263, in _error
    self.error_func(msg, location[0], location[1])
  File "/Users/louis/Workspace/Pyverilog/pyverilog/vparser/parser.py", line 67, in _lexer_error_func
    raise ParseError('%s: %s' % (coord, msg))
pyverilog.vparser.parser.ParseError:  line:5 column:13: Illegal character "'"

Note that some tools appear to treat '0 and 'd0 differently : ModelSim

I have never worked with lex or yacc but I might dig into it to try implementing this.

YSJL commented

Hey Louis were you able to fix this implementation?

YSJL commented

For whoever is going through this issue, you can edit lexer.py, parser.py, ast.py using already existing structures.

For lexer,py:

  • Add at line 89 within tokens = keywords + operators + ()
    'UNSIZEDNUMBER',
  • line 184
    unsized_number = '\'[0-1xXzZ?]'
  • line 218
    @TOKEN(unsized_number)
    def t_UNSIZEDNUMBER(self, t):
    return t

For parser.py:

  • line 1266
    def p_const_expression_unsizednum(self, p):
    'const_expression : unsizednumber'
    p[0] = UnsizedConst(p[1], lineno=p.lineno(1))
    p.set_lineno(0, p.lineno(1))
  • line 1281
    def p_unsizednumber(self, p):
    'unsizednumber : UNSIZEDNUMBER'
    p[0] = p[1]
    p.set_lineno(0, p.lineno(1))
  • line 1498
    def p_delays_unsizednumber(self, p):
    'delays : DELAY unsizednumber'
    p[0] = DelayStatement(UnsizedConst(
    p[2], lineno=p.lineno(1)), lineno=p.lineno(1))
    p.set_lineno(0, p.lineno(1))

For ast.py:

  • line 267
    class UnsizedConst(Constant):
    pass