Conflicting types for enum bool? - c

Question

I have a program that gives me the error [Error] conflicting types for 'empty' and [Error] conflicting types for 'full'. I have a hunch that it has something to do with the enum bool use (this is the first time I have tried using it). I've looked at other similar questions, that do not help me, were the issue is forgetting to declare a prototype in the program. I have made sure to write my functions before of main.
This is my code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct{
char** data; // array of strings represnting the stack
int top; // -1 if empty
int size;
}Stack;
typedef enum { FALSE, TRUE } bool;
Stack* create(){
Stack *s;
s = (Stack*)malloc(sizeof(Stack));
s->top = -1;
s->size = 10;
s->data = (char**)malloc(s->size*sizeof(char*));
return s;
}
void deleteStack(Stack* ps){
while(ps->top = 0){
free(ps->data[ps->top]);
ps->top--;
}
free(ps->data);
}
void push(Stack* ps, char* str, int* size){ //may need to call realloc bfr completing push
if(full(ps)){
char **temp = realloc(ps->data, ps->size*sizeof(char*));
ps->data == temp;
printf("Stack capacity has grown from %d to %d elements\n", ps->size**size, ps->size**(++size));
}
ps->data[++ps->top] = str;
}
char* pop(Stack* s, int* i){ //returns the string that was removed from the stack
if(empty(s))
return NULL;
printf("#of elements after popping: %d\tstring popped: %s\n", --i, s->data[s->top]);
return s->data[s->top--];
}
bool empty(Stack s){ // returns true if stack has no elements else false
if(s.top == -1)
return TRUE;
return FALSE;
}
bool full(Stack s){ //returns true if no more room else false
if(s.top == s.size-1)
return TRUE;
return FALSE;
}
int main(int argc, char *argv[]){
printf("Assignment 2 Problem 1 by Jasmine Ramirez\n");
FILE * input = fopen("data_a2.txt", "r");
if(input == NULL){
printf("File %s not found.\n", "data_a2.txt");
return -1;
}
Stack *s;
s = create();
char str[255];
int i = 0, size = 1;
while(fscanf(input, "%[^\n]", str) == 1){
i++;
if(strcmp(str, "pop") == 0){
i--;
pop(s, &i);
//printf("#of elements after popping: %d\tstring popped: %s", i, temp);
}
else{
push(s, str, &size);
}
}
deleteStack(s);
fclose(input);
return 0;
}
This is the input: (just in case)
to
sure
Be
pop
pop
pop
you
stop
won't
that
feeling
a
have
I
but
on
go
to
much
Not
right
Brilliant
happens
drink
pop
something
and
both
them
Ring
Story
ovaltine
your
pop
pop
Christmas
A
--
pop
pop
pop
pop
Ideas? Or am I just completely off?

Answer 1

In function push() you have:
void push(Stack* ps, char* str, int* size){
if(full(ps)){
…
This implicitly declares full as a function with indeterminate argument list returning an int. You later define it as returning a bool — these are different types, and hence you get the error.
Declare or define full before you use it. Similar comments apply to empty, but there's an additional problem in that code pointed out by Vlad from Moscow in his answer.
If you use GCC, use options such as -Wall -Wextra -Werror -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition -Wold-style-declaration (or as many of them as your version supports) to ensure that you don't run into this again.

Answer 2

The names empty and full are used before their declarations. For example
char* pop(Stack* s, int* i){ //returns the string that was removed from the stack
if(empty(s))
^^^^^^^^
return NULL;
printf("#of elements after popping: %d\tstring popped: %s\n", --i, s->data[s->top]);
return s->data[s->top--];
}
bool empty(Stack s){ // returns true if stack has no elements else false
if(s.top == -1)
return TRUE;
return FALSE;
}
You must to declare them before their usage.
And moreover for example the function empty has the parameter of the type Stack while is called with an argument of the type Stack *