Warning : assignment makes pointer from integer without a cast yylval=atoi(yytext);

Question

I am trying to write a simple calculator application using reentrant lex and yacc. Here I wish to create two threads (parser) which should parse input provided in input file. Lines to be parsed in input file are divided among two threads..

My lex code for simple calculator is

%option reentrant bison-bridge
%option noyywrap
%{
#include<stdio.h>
void yyerror(char *);
#include "y.tab.h"
%}

%%

[0-9]+ {
        yylval=atoi(yytext);
        return INTEGER;
        }

[-+\n]  return *yytext;

[ \t]   ;/* Skip whitespaces*/

.       ;

%%

My yacc file for simple calculator(reentrant) is

%pure-parser
%lex-param {void * scanner}
%parse-param {void * scanner}
%{
        #include <pthread.h>
        #include <sys/types.h>
        #include <sys/stat.h>
        #include <fcntl.h>
        #include<stdio.h>
        #include <stdlib.h>
        int f[2];
        pthread_mutex_t lock;
        int cnt=0;
        void* scanfunc(void * );
%}

%token INTEGER

%%

program: program expr '\n'      {printf("%d\n", $2);}
        |
        ;

expr:   INTEGER                 {$$=$1;}
        |expr '+' expr          {$$=$1+$3;}
        |expr '-' expr          {$$=$1-$3;}
        ;

%%

void yyerror(char *s){
        fprintf(stderr,"%s\n",s);
}
int main(int argc, char *argv[]){
        pthread_t threads[2];
        int n=2,i;//Number of threads to be created
        //set_file_ptr();

        if(argc!=2){
                printf("Insufficient nos. of arguments\n");
                exit(0);
        }
        for(i=0;i<n;i++){
                f[i]=open(argv[1],O_RDONLY);
                lseek(f[i],i*30,SEEK_SET);
        }
        printf("File pointer set\n");

        pthread_mutex_init(&lock,NULL);
        for(i=0;i<n;i++){
                pthread_create(&threads[i], NULL, (void *)scanfunc, (void *)&i);
        }

        //join all threads
        for(i=0;i<n;i++){
                pthread_join(threads[i],NULL);
        }

        pthread_mutex_destroy(&lock);
        //yyparse();
        return 0;
}
void* scanfunc(void * i)
{
    void * scanner;
   // printf("Value of i is %d\n",*(int *)i);
    printf("Starting thread %d...\n", *(int *)i);
    yylex_init(&scanner);
    printf("Done scanner init\n");
    pthread_mutex_lock(&lock);
    printf("Thread with id %d obtained lock\n",cnt);
    yyset_in(f[cnt],scanner);
    cnt++;
    pthread_mutex_unlock(&lock);
    yyparse(scanner);
    yylex_destroy(scanner);
}

and my input file is

12+12
14-12
23-11
12-12
23-45
67+45
11+23
45-12
67-12
90-34
56-56
90-45

when I compile and run this program I get followign output

File pointer set
Starting thread 0...
Starting thread 0...
Done scanner init
Thread with id 0 obtained lock
Done scanner init
Thread with id 1 obtained lock
Segmentation fault (core dumped)

When I debug this program using gdb it says that Program received signal SIGSEGV, Segmentation fault at below line.

yyparse(scanner);

I am unable to find out how to debug this program. Help in t his regard is appreciated. Thank you

Answer 1

Solved the issue of Warning : assignment makes pointer from integer without a cast yylval=atoi(yytext);

Referred Making bison/flex parser reentrant with integral YYSTYPE post to get to know that I have to make following changes in code to get rid of the warning.

*yylval=atoi(yytex)

Thank you