YACC PROBLEM - % type

[jenny__]

Good morning all!:KS

I would like your help on yacc program I have made!;)

%{

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* #include "parser.h" */

%}

%start program

%union {
char *string;
int integer;
}


%token <string> ID
%token <integer> NUMBER
%token <string> STRING
%token IF ELSE WHILE FOR
%token FUNCTION RETURN
%token TRUE FALSE NIL AND NOT OR

%left '='
%left "||"
%left "&&"
%nonassoc "==" "!="
%nonassoc '>' ">=" '<' "<="
%left '+' '-'
%left '*' '/' '%'
%right '!' "++" "--" UMINUS
%left '.'

%%

program: statements
;

statements: statements stmt
|
;

stmt:
';'
|expr ';'
|whilestmt
|forstmt
|returnstmt
|block
|funcdef
|ifstmt
;

expression:
assignexpr
|expr '+' expr { $$ = $1 + $3;} /* HERE IS THE PROBLEM *
/
|expr '-' expr
|expr '*' expr
|expr '/' expr /*{ if($3==0)
yyerror(.divide 0.);
else
$$ = $1 / $3;}
*/
|expr '%' expr
|expr '>' expr
|expr ">=" expr
|expr '<' expr
|expr "<=" expr
|expr "==" expr
|expr "!=" expr
|expr "&&" expr
|expr "||" expr
;


expr: expression
;
%%


int main() {

}



But it does not work!:confused:
In the example.y file we have the terminal symbols and non-terminal symbols.

The terminal symbols I use are NUMBER,ID,STRING.
I have defined a type for them
e.g. ID has a string value, NUMBER has an integer value etc
Well I'm :confused: as far as the % type is concerned.
We have to give a type to non terminals too.


If we do yacc example.y we take the output:


hello.y:58.36-37: $$ of `expression' has no declared type
hello.y:58.41-42: $1 of `expression' has no declared type
hello.y:58.46-47: $3 of `expression' has no declared type

This happens cause expression which is a non-terminal symbol has no type!

What type can this symbol take?shall i define a struct for this?

If i do : %type <integer> expression i take :

hello.y:61.18-30: warning: type clash on default action: <integer> != <>
hello.y:62.18-30: warning: type clash on default action: <integer> != <>
hello.y:63.18-30: warning: type clash on default action: <integer> != <>
hello.y:67.18-30: warning: type clash on default action: <integer> != <>
hello.y:68.18-30: warning: type clash on default action: <integer> != <>
hello.y:69.18-31: warning: type clash on default action: <integer> != <>
hello.y:70.18-30: warning: type clash on default action: <integer> != <>
hello.y:71.18-31: warning: type clash on default action: <integer> != <>
hello.y:72.18-31: warning: type clash on default action: <integer> != <>
hello.y:73.18-31: warning: type clash on default action: <integer> != <>
hello.y:74.18-31: warning: type clash on default action: <integer> != <>
hello.y:75.18-31: warning: type clash on default action: <integer> != <>


I would be really grateful if there is someone out there who can help me!

Thank you!

Have a nice day

Jenny

[bunker]

I'm not sure you can do this:



%token <string> ID
%token <integer> NUMBER
%token <string> STRING


When I made a compiler I used flex to get the tokens. In this way your grammar looks more like:



expr : expr TOKEN_PLUS expr { $$ = $1 + $3; }
| expr TOKEN_MINUS term { $$ = $1 - $3; }
;


Your syntax analyser will just repeatedly call the lexical analyser so you don't need any static definitions of tokens. Not positive if that's what you're aiming for - it might be overkill - but it's how I did it.

Another thing you might need is to define YYSTYPE in your declarations. This is the type of the $$ return. For me, I used a binary tree since I was just building up a complete parse tree of whatever the text was. I think it's integer by default.

(Also by the way you might want to use the code /code bbtags to put in big files like that - it's quite hard to see if there's just a simple error.)

[jenny__]

Well thanks for replying :)

I made a lexical analyser and i use in it the yyparse function :)

Well i do :

flex jenny.l
yacc jenny.y
gcc lex.yy.c y.tab.c -o jenny

and i take the output:

jenny.y: In function `yyparse':
jenny.y:84: error: invalid operands to binary +
jenny.y:85: warning: assignment makes pointer from integer without a cast
jenny.y:86: error: invalid operands to binary *
jenny.y:90: error: invalid operands to binary /
jenny.y:91: error: invalid operands to binary %
jenny.y:92: warning: assignment makes pointer from integer without a cast
jenny.y:93: warning: assignment makes pointer from integer without a cast
jenny.y:94: warning: assignment makes pointer from integer without a cast
jenny.y:95: warning: assignment makes pointer from integer without a cast
jenny.y:96: warning: assignment makes pointer from integer without a cast
jenny.y:97: warning: assignment makes pointer from integer without a cast
jenny.y:98: warning: assignment makes pointer from integer without a cast
jenny.y:99: warning: assignment makes pointer from integer without a cast

All these warnings and errors appear in the this part of the jenny.y program

/* line 82 */ expression:
assignexpr { $$ = $1;}
|expr '+' expr {$$ = $1 + $3;}
|expr '-' expr {$$ = $1 - $3;}
|expr '*' expr {$$ = $1 * $3;}
|expr '/' expr { if($3==0)
yyerror("divide 0");
else
$$ = $1 / $3;}
|expr '%' expr {$$ = $1 % $3;}
|expr '>' expr {$$ = ($1 > $3);}
|expr ">=" expr {$$ = $1 >= $3;}
|expr '<' expr {$$ = ($1) < ($3);}
|expr "<=" expr {$$ = $1 <= $3;}
|expr "==" expr {$$ = $1 == $3;}
|expr "!=" expr {$$ = $1 != $3;}
|expr "&&" expr {$$ = $1 && $3;}
|expr "||" expr {$$ = $1 || $3;}
|term {$$ = $1;}
;

The pink colour indicates error notice!

What shall i correct in these rules?

Thanks, in advance!!! :)

Be well!!!

[bunker]

Hm it still seems like a type error with YYSTYPE, but I'm really not positive how to fix it. This yacc tutorial (http://dinosaur.compilertools.net/yacc/index.html) seems a bit more relevant than my experience. (And also good in general: http://dinosaur.compilertools.net).

Sorry I couldn't help further. I have uploaded the stuff I did for the compiler in case that helps you. Here is the lex file (http://www.bananadine.co.uk/stuff/lex2.l) and yacc file (http://www.bananadine.co.uk/stuff/yacc3.y).

Edit: Fixed urls. It censors a*s (as in assignment) - that made chuckle :).

[jenny__]

Well i did what you told me with YYSTYPE and i placed in jenny.l

#define YYSTYPE Expr * ->> Expr is a struct which consists of

struct Expr
{
int intValue;
char *name;
double dval;
};

but again i take the same errors and warnings.

Well I have another question, in my system i have two versions of Yacc.

In the first version(older one) when i do : flex jenny.l everything is ok

In the second version (new one) when i do flex jenny.l i take

jenny.l:222: unrecognized rule
jenny.l:224: unrecognized rule
jenny.l:228: unrecognized rule
jenny.l:244: unrecognized rule

I think that these appear cause flex doen't recognise that way of writing these rules with pink

In jenny.l file i have written:

%x STRINGSTATE

%x COMMENTCONDITION1
%x COMMENTCONDITION2
%x COMMENTCONDITION3

{COMMENT1} {BEGIN(COMMENTCONDITION1);}

{COMMENT2} BEGIN(COMMENTCONDITION1);


<STRINGSTATE>{COMMENT3} BEGIN(COMMENTCONDITION2);

{COMMENT4} BEGIN(COMMENTCONDITION3);

The pink colour indicates where the problem is!

Do you have any idea on that?

Thanks for files you sent me! :) :KS

Jenny