Go Target, creates uncompilable xxx_parser.go

[hu1buerger]

• [x] I am not submitting a question on how to use ANTLR; instead, go to [antlr4-discussion google group]
• [x] I have done a search of the existing issues to make sure I'm not sending in a duplicate

What happens

When creating a parser/lexer -Dlanguage=Go the resulting code is not compilable. See the excerpt from smali_parser.go .

type SmaliParser struct {
	*antlr.BaseParser
}

// NewSmaliParser produces a new parser instance for the optional input antlr.TokenStream.
//
// The *SmaliParser instance produced may be reused by calling the SetInputStream method.
// The initial parser configuration is expensive to construct, and the object is not thread-safe;
// however, if used within a Golang sync.Pool, the construction cost amortizes well and the
// objects can be used in a thread-safe manner.
func NewSmaliParser(input antlr.TokenStream) *SmaliParser {
	this := new(SmaliParser)
	deserializer := antlr.NewATNDeserializer(nil)
	deserializedATN := deserializer.DeserializeFromUInt16(parserATN)
	decisionToDFA := make([]*antlr.DFA, len(deserializedATN.DecisionToState))
	for index, ds := range deserializedATN.DecisionToState {
		decisionToDFA[index] = antlr.NewDFA(ds, index)
	}
	this.BaseParser = antlr.NewBaseParser(input)

	this.Interpreter = antlr.NewParserATNSimulator(this, deserializedATN, decisionToDFA, antlr.NewPredictionContextCache())
	this.RuleNames = ruleNames
	this.LiteralNames = literalNames
	this.SymbolicNames = symbolicNames
	this.GrammarFileName = "SmaliParser.g4"

	return this
}

Similar issue in the lever

type SmaliLexer struct {
	*antlr.BaseLexer
	channelNames []string
	modeNames    []string
	// TODO: EOF string
}

// NewSmaliLexer produces a new lexer instance for the optional input antlr.CharStream.
//
// The *SmaliLexer instance produced may be reused by calling the SetInputStream method.
// The initial lexer configuration is expensive to construct, and the object is not thread-safe;
// however, if used within a Golang sync.Pool, the construction cost amortizes well and the
// objects can be used in a thread-safe manner.
func NewSmaliLexer(input antlr.CharStream) *SmaliLexer {
	l := new(SmaliLexer)
	lexerDeserializer := antlr.NewATNDeserializer(nil)
	lexerAtn := lexerDeserializer.DeserializeFromUInt16(serializedLexerAtn)
	lexerDecisionToDFA := make([]*antlr.DFA, len(lexerAtn.DecisionToState))
	for index, ds := range lexerAtn.DecisionToState {
		lexerDecisionToDFA[index] = antlr.NewDFA(ds, index)
	}
	l.BaseLexer = antlr.NewBaseLexer(input)
	l.Interpreter = antlr.NewLexerATNSimulator(l, lexerAtn, lexerDecisionToDFA, antlr.NewPredictionContextCache())

	l.channelNames = lexerChannelNames
	l.modeNames = lexerModeNames
	l.RuleNames = lexerRuleNames
	l.LiteralNames = lexerLiteralNames
	l.SymbolicNames = lexerSymbolicNames
	l.GrammarFileName = "SmaliLexer.g4"
	// TODO: l.EOF = antlr.TokenEOF

	return l
}

In this case the fields l.Interpreter, l.RuleNames , l.SymbolicNames, l.GrammarFileName are undefined.

What is supposed to happen

The resulting code should be compilable

How to reproduce

#!/bin/bash 
### In reference to this issue https://github.com/AlexeySoshin/smali2java/issues/11

rm -r antlr
mkdir antlr 

cd antlr 
antlr_file="antlr-4.9.2-complete.jar"
antlr_url="https://www.antlr.org/download/$antlr_file"
antlr_grammar_url="https://raw.githubusercontent.com/psygate/smali-antlr4-grammar/acff6f3afcfa9f6c49cc40aa55360447d88c58ca"

# filenames 
smaliLexer="SmaliLexer.g4"
smaliParser="SmaliParser.g4"

curl_cmd="curl --silent"
$curl_cmd --output $antlr_file $antlr_url
$curl_cmd --output $smaliLexer $antlr_grammar_url/$smaliLexer
$curl_cmd --output $smaliParser $antlr_grammar_url/$smaliParser

java -cp $antlr_file org.antlr.v4.Tool -Dlanguage=Go -visitor -o gen $smaliLexer
java -cp $antlr_file org.antlr.v4.Tool -Dlanguage=Go -visitor -o gen $smaliParser

[kaby76]

Compiles without any errors for me, Msys2/Win10. What is your Go version?

$ make
java -jar c:/users/kenne/downloads/antlr-4.9.2-complete.jar -encoding utf-8 -Dlanguage=Go -o parser -lib parser  parser/SmaliLexer.g4
java -jar c:/users/kenne/downloads/antlr-4.9.2-complete.jar -encoding utf-8 -Dlanguage=Go -o parser -lib parser  parser/SmaliParser.g4
export GO111MODULE=auto; go build Program.go
export GO111MODULE=auto; go get github.com/antlr/antlr4/runtime/Go/antlr
$ go version
go version go1.16 windows/amd64

o.tar.gz

That said, I have problems with the implementation of superClass with Go. And, it is known to be slow.

[sheik]

This is because you are using the visitor pattern which is not fully implemented. I have opened a PR to hopefully fix this.

https://github.com/antlr/antlr4/pull/3299

[hu1buerger]

Any updates?