Generate python3 parser file contains a syntax error?

[ldorigo]

I tried generating parsers/lexers using the files at https://github.com/ethereum/solidity/blob/develop/docs/grammar/SolidityLexer.g4 and https://github.com/ethereum/solidity/blob/develop/docs/grammar/SolidityParser.g4 using target=Python3.

The generated Python parser contains syntax errors (exclamation marks before variables and "true" instead of "True"?), e.g.:

                    elif la_ == 4:
                        self.state = 392
[SolidityParser.py.txt](https://github.com/antlr/antlr4/files/12861363/SolidityParser.py.txt)

                        if not !localctx.visibilitySet:
                            from antlr4.error.Errors import FailedPredicateException
                            raise FailedPredicateException(self, "!$visibilitySet")
                        self.state = 393
                        self.match(SolidityParser.Public)
                        localctx.visibilitySet =  true
                        pass

I attach the generated file for reference. This is with antlr 4.13.1.

[ldorigo]

SolidityParser.py.txt Forgot the attachement

[ldorigo]

For reference, the exact commands I used are:

antlr4 -Dlanguage=Python3 SolidityLexer.g4
antlr4 -Dlanguage=Python3 SolidityParser.g4

[kaby76]

That grammar, and in particular SolidityParser.g4, contains locals and actions, both of which are in a target specific language. While it is not declared with a language option, it is most likely Java. Python3 does not have type declarations, and True and False are the literals in the language, not true and false. You will need to make a port of the grammar for Python3. There is a target-independent grammar in grammars-v4, but it may be quite old.