Problem generating code from bison

[Manish Katiyar]

Hello friends,
  I downloaded the bison-2.1 and built it on an HPUX-Itanium machine.
Now whenever i try to compile the C file generated from bison I am
getting syntax errors. I am generating with the command "bison -d a.y"
and running it with "cc a.tab.c" ........Is there anything that we
need to specify on Itanium to work???

My .y file looks like this which I downloaded from a site. Please help

/* example.y */
%{
#define YYSTYPE int
%}
%token PLUS MINUS STAR LPAREN RPAREN NUMBER NEWLINE
%left PLUS MINUS
%left STAR

%%
line : /* empty */
    | line expr NEWLINE      { printf("%d\n", $2); }
expr : LPAREN expr RPAREN     { $$ = $2; }
    | expr PLUS expr         { $$ = $1 + $3; }
    | expr MINUS expr        { $$ = $1 - $3; }
    | expr STAR expr         { $$ = $1 * $3; }
    | NUMBER                 { $$ = $1; }
    ;

%%

int yyerror (char const *msg) {
   printf("Error: %s\n", msg);
}

int main() {
   printf("%d\n", yyparse());
   return 0;
}

The Flex lexer used by this parser looks like this:

/* example.lex */
%{
#include "example.parser.h"
%}
%option noyywrap

%%

[ \t]+    { /* ignore whitespace */ }
"("       { return LPAREN; }
")"       { return RPAREN; }
"+"       { return PLUS; }
"-"       { return MINUS; }
"*"       { return STAR; }
\n        { return NEWLINE; }
[0-9]+    { yylval = atoi(yytext); return NUMBER; }
.         { printf("Invalid character '%s'", yytext); }

%%



The errors which i am getting are

Warning 361: "a.y", line 21 # Value-returning function might end
without executing a return statement.
   int yyerror (char const *msg) {
       ^^^^^^^
Error 419: "a.y", line 30 # 'The' is used as a type, but has not been
defined as a type.
   The Flex lexer used by this parser looks like this:
   ^^^
Error 20: "a.y", line 30 # ';' expected before 'lexer'.
   The Flex lexer used by this parser looks like this:
            ^^^^^
Error 419: "a.y", line 30 # 'lexer' is used as a type, but has not
been defined as a type.
   The Flex lexer used by this parser looks like this:
            ^^^^^
Error 20: "a.y", line 30 # ';' expected before 'by'.
   The Flex lexer used by this parser looks like this:
                       ^^
Error 419: "a.y", line 30 # 'by' is used as a type, but has not been
defined as a type.
   The Flex lexer used by this parser looks like this:
                       ^^
Error 20: "a.y", line 30 # ';' expected before 'parser'.
   The Flex lexer used by this parser looks like this:
                               ^^^^^^
Error 419: "a.y", line 30 # 'parser' is used as a type, but has not
been defined as a type.
   The Flex lexer used by this parser looks like this:

--
Thanks & Regards,
********************************************
Manish Katiyar
Ozone 2, SP Infocity (Software Park),
New Survey #208 Manjari Stud Farms Ltd.,
Phursungi Village, Haveli Taluka, Saswad Road,
Hadapsar, Pune - 412308, India
***********************************************