#include<stdio.h>
#include<stdlib.h>
#define GREY 1
#define BLACK 0
#define WHITE 2
typedef struct node * graph;
typedef struct stack * snode;
extern int stack_counter;
graph cnode(int data); //cnode is to create a node for graph
void cgraph(void);
struct node {
int data, color;
struct node *LEFT, *RIGHT, *TOP, *DOWN;
};//this structure defines a node of the graph
struct stack {
struct stack *priv;
struct cgraph *graph_node;
};// this is to define a structure which should hold node of a structure
extern snode sroot;I defined a header file (declaration.h) as above and following is a c program(stack.c)
#include<declarations.h>
void cstack (graph temp);
void stackpush(snode stemp);
stack_counter = 0;
sroot=NULL;
void cstack (graph gtemp) //cstack is to create stack
{
snode spriv,some;
if (stack_counter==0)
{
sroot=cstacknode(gtemp);
spriv=sroot;
stack_counter++;
}
else{
some=cstacknode(gtemp);
some->priv=spriv;
spriv=some;
}
}
//struct stack is representing a stack
//struct node is representing a node in graph
snode cstacknode (graph gtemp)
//this function should create a node of the stack which should be storing the graph node as a pointer
{
snode an;
an=(snode)malloc(sizeof(snode));
an->graph_node=gtemp;
an->priv=NULL;
return an;
}
void stackpush(snode stemp)
{
}I am making which would be used in the library I am developing
both the above files are in same directory.
I compiled the above file stack.c as
cc -I ./ stack.cand got following warnings
stack.c:4: warning: data definition has no type or storage class
stack.c:6: warning: data definition has no type or storage class
stack.c:6: error: conflicting types for ‘sroot’
./declarations.h:21: note: previous declaration of ‘sroot’ was here
stack.c:6: warning: initialization makes integer from pointer without a cast
stack.c: In function ‘cstack’:
stack.c:13: warning: assignment makes pointer from integer without a cast
stack.c:17: warning: assignment makes pointer from integer without a cast
stack.c: At top level:
stack.c:27: error: conflicting types for ‘cstacknode’
stack.c:12: note: previous implicit declaration of ‘cstacknode’ was here
stack.c: In function ‘cstacknode’:
stack.c:32: warning: assignment from incompatible pointer typefrom this set of warnings I want to understand following warnings
stack.c:4: warning: data definition has no type or storage class
stack.c:6: warning: data definition has no type or storage classThe above warning is coming from file stack.c
and line 4 and 6 in stack.c have
stack_counter = 0;
sroot=NULL;and both the above variables I have defined in declarations.h so why do I get the above warning ?
