Backward Compatibility

[Byungjun Yu]

Hi

Are there any references I can look up for translating ANTLR 3.X grammar to 4.X grammar?

I'm trying to modify an existing grammar, which was written by ANTLR 3.3, to comply with ANTLR 4.1.

And when I compile the grammar(ANTLR 3.3) with ANTLR 4.1, there are lots of errors and warning.

Thanks, BJ.

[Jim Idle]

Just start by taking out all the syntactic predicates. It should pretty much just work at that point. 

So:

(rule)=>rule      change to just rule

(TOKEN)=>TOKEN     change to token

See how many errors you have left after that.

Jim

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[Byungjun Yu]

Thank you for reply.

Though, after removing all the syntactic predicates, there are still some errors. 

Below are examples.

e.g. 

error message: 

action in lexer rule 'PP_EQUALITY_EXPRESSION' must be last element of single outermost alt.

related grammar:

fragment

PP_PRIMARY_EXPRESSION:

IDENTIFIER

{ 

Returns.Push(MacroDefines.ContainsKey($IDENTIFIER.Text));

}

| '('   PP_EXPRESSION   ')'

;

error message:

redefinition of 'members' action 

related grammar:

@lexer::members {

// Preprocessor Data Structures - see lexer section below and PreProcessor.cs

protected Dictionary<string,string> MacroDefines = new Dictionary<string,string>();

protected Stack<bool> Processing = new Stack<bool>();

// Uggh, lexer rules don't return values, so use a stack to return values.

protected Stack<bool> Returns = new Stack<bool>();

}

@members

{

protected bool is_class_modifier() 

{

return false;

}

}

Thank you. 

BJ

2013년 7월 5일 금요일 오후 12시 10분 7초 UTC+9, Jim Idle 님의 말: