C - redefinition error in Xcode

Question

My c header file has the following error message in Xcode

Redefinition of 'entry'

But it works perfectly when I compile it using gcc in command line. Could any of you give an explanation of why?

This is snapshot.h:

#ifndef SNAPSHOT_H
#define SNAPSHOT_H

#define MAX_KEY_LENGTH 16
#define MAX_LINE_LENGTH 1024

typedef struct value value;
typedef struct entry entry;
typedef struct snapshot snapshot;

struct value {
    value* prev;
    value* next;
    int value;
};

// the line below is where the redefinition error appears
struct entry {
    entry* prev;
    entry* next;
    value* values;
    char key[MAX_KEY_LENGTH];
};

struct snapshot {
    snapshot* prev;
    snapshot* next;
    entry* entries;
    int id;
};

#endif

This is snapshot.c:

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include "snapshot.h"

int
main(int argc, char *argv[]){
    int x = 7;
    printf("x= %d\n" , x);
    printf("value = %d\n", 1);
    return 0;
}

Is that the *complete* error? Please edit your question to include the compete and unedited error output. — Some programmer dude, Apr 29 '15 at 06:38
Yes. That was the complete error. @Benjy's answer has well solved that. Thanks for Paul's comment too. — hexinpeter, Apr 29 '15 at 12:46

score 6 · Accepted Answer · edited May 23 '17 at 12:16

6

entry was originally reserved as a keyword and then later declared obsolete. So older compilers don't allow it (see this question). Change the name of the struct and everything should be fine.

edited May 23 '17 at 12:16

Community

1
1

answered Apr 29 '15 at 06:38

Benjy Kessler

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Alternatively compiling with e.g. `-std=c99` may fix this. – Paul R Apr 29 '15 at 06:40

C - redefinition error in Xcode

1 Answers1