Possible stack corruption in C - c

While trying to pass an argument to a function; the function receives the wrong value thus creating a segmentation fault while trying to use that value
argc and argv in the main function are corrupted before the program even starts
main.c file:
#include <stdio.h>
#include <stdlib.h>
#include "util/BasicTypes.h"
#include "util/IncludeOpengl.h"
#include "util/Vec2.h"
#include "util/Vec3.h"
#include "util/Vec4.h"
#include "util/Vector.h"
#if !(defined(__linux__) || defined(_WIN64))
STATIC_ASSERT(false, unsupported_system)
#endif
i32 main(i32 argc, ch8** argv) {
//u32 a[] = {1, 2, 3, 4};
//u32* b = a;
u32 i;
Vector v;
init_Vector(&v, sizeof(u32));
for (i = 0; i < 4; i++) {
printf("%i\n", i);
Vector_append(&v, &i);
}
for (i = 0; i < Vector_getSize(&v); i++) {
printf("%i\n", Vector_get(&v, i));
}
destruct_Vector(&v);
return 0;
}
vector.c file where i define the vector functions:
#ifndef VECTOR_C
#define VECTOR_C
#include "../util/Vector.h"
#include "../util/BasicTypes.h"
#include "../util/Assert.h"
void init_Vector(Vector* self, u32 elementSize) {
self->elementSize = elementSize;
self->elements = NULL;
self->elementCount = 0;
}
void destruct_Vector(Vector* self) {
if (self->elements) {
heapFree(self->elements);
}
}
void Vector_append(Vector* self, void* element) {
if (self->elements) {
self->elements = heapRealloc(self->elements, self->elementCount + 1);
memcpy(((byte*)self->elements) + (self->elementCount) * self->elementSize, element, self->elementSize);
self->elementCount += 1;
return;
}
else {
self->elements = heapAlloc((usize)self->elementSize);
memcpy(self->elements, element, self->elementSize);
self->elementCount += 1;
return;
}
}
void Vector_remove(Vector* self, u32 id) {
if (id < self->elementCount) {
void* temp = self->elements;
self->elements = heapAlloc((self->elementCount - 1) * self->elementSize);
memcpy(self->elements, temp, id * self->elementSize);
memcpy(((byte*)self->elements) + id * self->elementSize, ((byte*)temp) + (id + 1) * self->elementSize, (self->elementCount - id - 1) * self->elementSize);
self->elementCount -= 1;
}
else {
ASSERT(false, "(Vector_remove) id is not in the list");
}
}
void Vector_insert(Vector* self, void* element, u32 id) {
if (!self->elements && !id) {
self->elements = heapAlloc(self->elementSize);
self->elementCount = 1;
}
else {
if (id < self->elementCount + 1) {
void* temp = self->elements;
self->elements = heapAlloc((self->elementCount - 1) * self->elementSize);
memcpy(self->elements, temp, id * self->elementSize);
memcpy(((byte*)self->elements) + (id + 1) * self->elementSize, ((byte*)temp) + (id) * self->elementSize, (self->elementCount - id - 1) * self->elementSize);
memcpy(((byte*)self->elements), ((byte*)temp), self->elementSize);
self->elementCount += 1;
}
else {
ASSERT(false, "(Vector_insert) id is too far");
}
}
}
void* Vector_get(Vector* self, u32 id) {
return ((byte*)self->elements) + id * self->elementSize;
}
u32 Vector_getSize(Vector* self) {
return self->elementCount;
}
#endif // VECTOR_C
vector.h file the header file for vector.c:
#ifndef VECTOR_H
#define VECTOR_H
#include "../util/BasicTypes.h"
typedef struct Vector {
void* elements;
u32 elementSize;
u32 elementCount;
} Vector;
void init_Vector(Vector* self, u32 elementSize);
void destruct_Vector(Vector* self);
void Vector_append(Vector* self, void* element);
void Vector_remove(Vector* self, u32 id);
void Vector_insert(Vector* self, void* element, u32 id);
void* Vector_get(Vector* self, u32 id);
u32 Vector_getSize(Vector* self);
#endif // VECTOR_H
basictypes.h file where i define some aliases:
#ifndef BASIC_TYPES_H
#define BASIC_TYPES_H
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
typedef int8_t i8;
typedef int16_t i16;
typedef int32_t i32;
typedef int64_t i64;
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;
typedef i8 ch8;
typedef i16 ch16;
typedef i32 ch32;
typedef i64 ch64;
typedef u8 uch8;
typedef u16 uch16;
typedef u32 uch32;
typedef u64 uch64;
typedef float f32;
typedef double f64;
typedef long double f128;
typedef u8 byte;
typedef size_t usize;
#endif // BASIC_TYPES_H

typedef i8 ch8; is wrong, since int8_t might likely expand to signed char, which in turn is not directly compatible with char unless you explicitly covert between the two types.
The format of main is not for the programmer to decide, but the compiler. gcc under strict compliance settings (-pedantic-errors) tells you this much:
error: second argument of 'main' should be 'char **' [-Wmain]
Besides, nobody wants to read code based on your own special type system. We have standards for a reason, so use standard C instead:
#include <stdint.h>
....
int main (int argc, char* argv[])
{
uint32_t i;

Related

invalid use of incomplete typedef in C

I'm implementing a data structure in C and I get this error in my test file. Without adding code because then that would be a huge post with a ton of code to go through, but here's what my code looks like:
header.h file:
typedef struct array Arr;
functions.c file:
#include "header.h"
struct array{
int number;
int size;
char *names;
}
main.c file:
#include "header.h"
bool function(const Arr *const variable)
{
for (int i = 0; i < variable->size; i++)
{
variable->number[i] = i;
}
}
and so I get the error mentioned in the title referring to Arr*->number and Arr->*size. What I suspect to be the issue is that Arr is only typedefed but not defined. If that's the case, how can I resolve it?
Here's the main code:
main.c
#include <stdio.h>
#include "header.h"
int main(){
set *setA = set_empty();
set_insert(69,setA );
set_insert(15, setA);
set *setB = set_empty();
set_insert(12,setB );
set_insert(15, setB);
set *setDiff = set_difference(setA, setB);
printf("\n");
print_set(setDiff);
bool diff = verify_difference(setDiff, setA, setB);
}
bool verify_difference(const set *const setDiff, const set *const setA, const struct set *const setB)
{
bool answer = true;
for (int x = 0; x < setDiff->size; x++)
{
if (set_member_of(setDiff->array[x], setA) && set_member_of(setDiff->array[x], setB))
{
answer = false;
break;
}
}
return answer;
}
header.h
#ifndef HEADER_H
#define HEADER_H
#include <stdbool.h>
typedef struct set set;
set *set_empty();
void set_insert(const int value, set *s);
bool set_member_of(const int value, const set *const s);
functions.c
#include <stdio.h>
#include "header.h"
struct set {
int capacity;
int size;
char *array;
};
set *set_empty()
{
struct set *ptr = malloc(sizeof(struct set));
ptr->size = 0;
ptr->array = malloc(sizeof(char));
ptr->capacity = 1;
return ptr;
}
void set_insert(const int value, set *s)
{
if (!set_member_of(value, s)) {
int bit_in_array = value; // To make the code easier to read
// Increase the capacity if necessary
if (bit_in_array >= s->capacity) {
int no_of_bytes = bit_in_array / 8 + 1;
s->array = realloc(s->array, no_of_bytes);
for (int i = s->capacity / 8 ; i < no_of_bytes ; i++) {
s->array[i] = 0;
}
s->capacity = no_of_bytes * 8;
}
// Set the bit
int byte_no = bit_in_array / 8;
int bit = 7 - bit_in_array % 8;
s->array[byte_no] = s->array[byte_no] | 1 << bit;
s->size++;
}
}
set *set_difference(const set *const s1, const set *const s2)
{
struct set *s = set_empty();
for (int i = 0; i < s1->size; i++)
{
if (!set_member_of(s1->array[i], s2))
{
set_insert(s1->array[i], s);
}
}
for (int i = 0; i < s2->size; i++)
{
if (!set_member_of(s2->array[i], s1))
{
set_insert(s2->array[i], s);
}
}
return s;
}
bool set_member_of(const int value, const set *const s)
{
int bit_in_array = value;
if (bit_in_array >= s->capacity) {
return false;
}
int byte_no = bit_in_array / 8;
int bit = 7 - bit_in_array % 8;
char the_byte = s->array[byte_no];
return the_byte & 1 << bit;
}
The definition of the structure shall be available in main. Otherwise the compiler does not know whether there is the data member number in the structure referred in this statement
Arr->number[i] = i;
Moreover in any case this statement is incorrect because Arr is a type specifier and according to the structure definition the data member number is not an array
It seems you mean
variable[i].number = i;
But as the function parameter
bool function(const Arr *const variable)
is declared as a pointer to a constant object then you may not change pointed to data members of the structure.
So either move the definition of the function function from main.c in functions.c or place the structure definition in the header file.
And there is a typo
Typedef struct array Arr;
^^T
you need to use lower case letter
typedef struct array Arr;
I can only hazard a guess. Your code snippet could be wrong.
Move the structure definition to header.h & check.
//header.h file:
typedef struct array Arr;
struct array{
int number;
int size;
char *names;
};

arraylist implementation stop working after appending 32754 elements

My arraylist implementation stop working after appending 32754 elements. I think it is very weird that this problem only occurs after appending so many elements and 32000 is still not too high to reach I know I am not checking for NULL pointer and that my test program is a infinite loop. I am using a old version to reduce the code complexity.
output:
32752
32753
32754
zsh: segmentation fault ./acl
array.c:
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
union arraylist_meta {
double dummy_double;
long double dummy_long_double;
long long dummy_long_long;
void *dummy_ptr;
void (*dummy_func_ptr)(void);
struct {
size_t len;
size_t cap;
size_t sizeof_one_element;
};
};
void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element) {
union arraylist_meta *arraylist_new = malloc(array_size * sizeof_one_element + sizeof*arraylist_new);
arraylist_new->len = array_size;
arraylist_new->cap = array_size;
arraylist_new->sizeof_one_element = sizeof_one_element;
return arraylist_new+1;
}
void* acl_arraylist_append(void *arraylist_void, void *element) {
union arraylist_meta *arraylist = arraylist_void;
--arraylist;
if(arraylist->len == arraylist->cap) {
arraylist->cap = arraylist->len + 10;
arraylist = realloc(arraylist, arraylist->cap * arraylist->sizeof_one_element + sizeof *arraylist);
}
memcpy((char*)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len, element, arraylist->sizeof_one_element);
++arraylist->len;
return arraylist+1;
}
array.h:
#ifndef array_h
#define array_h
#include <stddef.h>
void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element);
void* acl_arraylist_append(void *arraylist_void, void *element_void);
#endif
a simple test programm:
#include <acl/array.h>
#include <stdio.h>
#include <stdlib.h>
int main() {
int *num = acl_arraylist_create(0, sizeof *num);
for(int i = 0;;++i) {
num = acl_arraylist_append(num, &i);
printf("%d\n", i);
}
}
Edit:
I changed the of the executable a while ago. By reverting a few commits back my build script was using the old name again, but executed the executable with name. This means that the problem I describe above does not with code above. It only occurs when using the code below:
array.c:
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <acl/array.h>
size_t acl_arraylist_len(void *arraylist);
void acl_arraylist_free(void *arraylist);
static inline void* acl_arraylist_resize(union acl_arraylist_meta *arraylist, int64_t relativLen) {
size_t cap = arraylist->cap + relativLen;
arraylist = realloc(arraylist, cap * arraylist->sizeof_one_element + sizeof *arraylist);
if(arraylist != NULL) {
arraylist->cap = cap;
}
return arraylist;
}
void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element) {
union acl_arraylist_meta *arraylist_new = malloc(array_size * sizeof_one_element + sizeof*arraylist_new);
if(arraylist_new == NULL) return NULL;
arraylist_new->len = array_size;
arraylist_new->cap = array_size;
arraylist_new->sizeof_one_element = sizeof_one_element;
return arraylist_new+1;
}
void* acl_arraylist_append(void *arraylist_void, void *element) {
void *element_append;
union acl_arraylist_meta *arraylist = acl_arraylist_append_ptr(arraylist_void, &element_append);
if(arraylist == NULL) return NULL;
--arraylist;
memcpy(element_append, element, arraylist->sizeof_one_element);
return arraylist + 1;
}
void* acl_arraylist_append_ptr(void *arraylist_void, void **append_element) {
union acl_arraylist_meta *arraylist = arraylist_void;
--arraylist;
if(arraylist->len == arraylist->cap) {
acl_arraylist_resize(arraylist, 10);
if(arraylist == NULL) return NULL;
}
*append_element = (char*)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len;
++arraylist->len;
return arraylist + 1;
}
void* acl_arraylist_remove(void *arraylist_void, size_t index) {
union acl_arraylist_meta *arraylist = (union acl_arraylist_meta*)arraylist_void - 1;
char *arraylist_char = arraylist_void;
if(index != arraylist->len - 1) {
memcpy(arraylist_char + arraylist->sizeof_one_element * index, arraylist_char + arraylist->sizeof_one_element * (arraylist->len - 1), arraylist->sizeof_one_element);
}
--arraylist->len;
if(arraylist->len < arraylist->cap - 20) {
void* arraylistTmp = acl_arraylist_resize(arraylist, -10);
if(arraylistTmp != NULL) arraylist = arraylistTmp;
}
return arraylist + 1;
}
array.h:
#ifndef _acl_array_h
#define _acl_array_h
#include <stddef.h>
#include <stdlib.h>
union acl_arraylist_meta {
double dummy_double;
long double dummy_long_double;
long long dummy_long_long;
void *dummy_ptr;
void (*dummy_func_ptr)(void);
struct {
size_t len;
size_t cap;
size_t sizeof_one_element;
};
};
inline size_t acl_arraylist_len(void *arraylist) {
return ((union acl_arraylist_meta*)arraylist - 1)->len;
}
inline void acl_arraylist_free(void *arraylist) {
free((union acl_arraylist_meta*)arraylist-1);
}
void* acl_arraylist_remove(void *arraylist_void, size_t index);
void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element);
void* acl_arraylist_append(void *arraylist_void, void *element);
void* acl_arraylist_append_ptr(void *arraylist_void, void **append_element);
#endif
a simple test programm:
#include <acl/array.h>
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
void *num = acl_arraylist_create(100, sizeof(int));
for (int i = 0; i < 65536; ++i)
{
num = acl_arraylist_append(num, &i);
printf("%d\n", i);
}
}
It's worrying that your array.c source file does not include the header (acl/array.h) that declares the services that the source file defines. It means there is no cross-checking. The headers provide the glue that holds C programs together, providing cross-checking to ensure that the code using the services provided agrees with the code providing those services.
Also: Your sample program doesn't create a list — your code should not compile because num is not defined.
When resequenced a bit, the code does compile cleanly. When I added a call:
void *num = acl_arraylist_create(100, sizeof(int));
before the loop in main() and ran the code (source code acl23.c, program acl23), I got to iteration 150 before the Mac OS library said:
acl23(54767,0x10d41b5c0) malloc: *** error for object 0x7f8c40c02bb0: pointer being realloc'd was not allocated
acl23(54767,0x10d41b5c0) malloc: *** set a breakpoint in malloc_error_break to debug.
If you've got Valgrind available to you, use it.
I think your code is playing with fire (and you're getting burnt) because you're trying to combine the union arraylist_meta structure and the array data.
However, the primary problem is that when the memory is reallocated, you are not using the new value returned by acl_arraylist_append(). Change the line in the loop to:
new = acl_arraylist_append(num, &i);
and the code runs up to 65535 for me. I set the loop to stop then, rather than imposing no limit.
for (int i = 0; i < 65536; ++i).
It isn't clear how the user of your array list is going to access elements of the array. Presumably, you plan to have them convert the void * (num in the example) to an appropriate typed pointer (int *array = num;) and they can then index into the array. It's also not clear how they determine the size of the array — what the maximum index is. You've also not provided a function to free the array. The user can't do that — the pointer they have is not the one returned by one of the allocation functions (malloc(), realloc(), etc). None of these are immediately critical; we can safely assume that they were omitted from the
MCVE (Minimal, Complete, Verifiable Example — or MRE or whatever name SO now uses) you provided.
Here's my working code derived from yours — all in a single file. The changes are actually quite minor.
/*array.h:*/
#ifndef array_h
#define array_h
#include <stddef.h>
void *acl_arraylist_create(size_t array_size, size_t sizeof_one_element);
void *acl_arraylist_append(void *arraylist_void, void *element_void);
#endif
/*array.c:*/
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
/*#include <acl/array.h>*/
union arraylist_meta
{
double dummy_double;
long double dummy_long_double;
long long dummy_long_long;
void *dummy_ptr;
void (*dummy_func_ptr)(void);
struct
{
size_t len;
size_t cap;
size_t sizeof_one_element;
};
};
void *acl_arraylist_create(size_t array_size, size_t sizeof_one_element)
{
union arraylist_meta *arraylist_new = malloc(array_size * sizeof_one_element + sizeof *arraylist_new);
arraylist_new->len = array_size;
arraylist_new->cap = array_size;
arraylist_new->sizeof_one_element = sizeof_one_element;
return arraylist_new + 1;
}
void *acl_arraylist_append(void *arraylist_void, void *element)
{
union arraylist_meta *arraylist = arraylist_void;
--arraylist;
if (arraylist->len == arraylist->cap)
{
arraylist->cap = arraylist->len + 10;
arraylist = realloc(arraylist, arraylist->cap * arraylist->sizeof_one_element + sizeof *arraylist);
}
memcpy((char *)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len, element, arraylist->sizeof_one_element);
++arraylist->len;
return arraylist + 1;
}
/*a simple test programm:*/
/*#include <acl/array.h>*/
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
void *num = acl_arraylist_create(100, sizeof(int));
for (int i = 0; i < 65536; ++i)
{
num = acl_arraylist_append(num, &i);
printf("%d\n", i);
}
}
I'm not going to show the output; the numbers from 1 to 65535 are not exciting.
I distrust void * as the handle type for your array. The user could provide any pointer of their choosing as a handle and there's no way to know that it's the wrong type of pointer. Provide an opaque type instead; in the header, define:
typedef struct acl_arraylist acl_arraylist;
Then have the functions take and return an acl_arraylist *. The client code doesn't need to know what's in it. Your code in array.c might wrap the union arraylist_meta value into a structure:
struct acl_arraylist
{
union arraylist_meta array;
};
You can then play in much the same way you did before. But the user has to work to pass an arbitrary pointer to the functions — sufficiently hard that they won't get it wrong.
The new pointer returned from acl_arraylist_resize is ignored in acl_arraylist_append_ptr.
modified code:
void* acl_arraylist_append_ptr(void *arraylist_void, void **append_element) {
union acl_arraylist_meta *arraylist = arraylist_void;
--arraylist;
if(arraylist->len == arraylist->cap) {
arraylist = acl_arraylist_resize(arraylist, 10);// this line was modified
if(arraylist == NULL) return NULL;
}
*append_element = (char*)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len;
++arraylist->len;
return arraylist + 1;
}

Why do i get invalid use of void expression?

I want to recreate vectors in c, and i get an invalid use of void expression error. I have tried it like this.
typedef struct {
void *data;
int size;
int capacity;
} vec;
#define vec_new(name, type) vec name; (name).size = 0; (name).capacity = 8; {\
void *vec_temp; vec_temp = calloc(8, sizeof(type));\
while (vec_temp == NULL) { vec_temp = calloc(8, sizeof(type)); }\
(name).data = vec_temp;\
}
#define vec_set(vec, index, value, type) *( (type*) (vec).data[(index)] ) = value;
#define vec_get(vec, index, type) *( (type*) (vec).data[(index)] )`
I get the error in the set and get macros
You are indexing a void* type with the way things are. You are typecasting (vec).data[(index)] to type*, you should be casting ((vec).data) to type*
Try this instead:
#define vec_set(vec, index, value, type) ((type*) (vec).data)[(index)] = value;
#define vec_get(vec, index, type) (((type*) (vec).data)[(index)])
You are getting invalid use of void expression cos we cant do void* arithmatics and dereference ! you need to cast the data struct member and you did it wrong.
#include <stdio.h>
#include <stdlib.h>
typedef struct {
void *data;
int size;
int capacity;
} vec;
#define vec_new(name, type) vec name; (name).size = 0; (name).capacity = 8; {\
void *vec_temp; vec_temp = calloc(8, sizeof(type));\
while (vec_temp == NULL) { vec_temp = calloc(8, sizeof(type)); }\
(name).data = vec_temp;\
}
#define vec_set(vec, index, value, type) (*( ( (type*) (vec).data ) + (index) ) ) = value;
#define vec_get(vec, index, type) (*( ( (type*) (vec).data ) + (index) ) )
int main()
{
vec_new(p, int);
vec_set(p,0,5,int);
int g = vec_get(p, 0, int);
printf("%d",g);
return 0;
}

microECC - dereferencing pointer to incomplete type

When I try to compile this project I receive an error like this:
dereferencing pointer to incomplete type ‘const struct uECC_Curve_t’ uECC_generate_random_int(r, curves[0]->n, BITS_TO_WORDS(curves[0]->num_n_bits));
I searched several times on Stackoverflow a method to solve this error without success. May I ask you what is wrong in this operation? Why cannot I recover the EC curve parameter n in this manner curves[0]->n?
#include "uECC.h"
#include <stdio.h>
#include <string.h>
void vli_print(char *str, uint8_t *vli, unsigned int size)
{
printf("%s ", str);
for (unsigned i = 0; i < size; ++i)
{
printf("%02X ", (unsigned)vli[i]);
}
printf("\n");
}
int main()
{
uint8_t private[32] = {0};
uint8_t public[64] = {0};
unsigned int r[21];
const struct uECC_Curve_t *curves[1];
int num_curves = 0;
#if uECC_SUPPORTS_secp160r1
curves[num_curves++] = uECC_secp160r1();
#endif
uECC_generate_random_int(r, curves[0]->n, BITS_TO_WORDS(curves[0]->num_n_bits));
memset(public, 0, sizeof(public));
if (!uECC_make_key(public, private, curves[0]))
{
printf("uECC_make_key() failed\n");
}
vli_print("Provided public key = ", public, sizeof(public));
vli_print("Private key = ", private, sizeof(private));
return 0;
}
uECC.h
struct uECC_Curve_t;
typedef const struct uECC_Curve_t * uECC_Curve;
uECC.c (I call it during the compilation with gcc, e.g. gcc -o test test.c uECC.c)
struct uECC_Curve_t {
wordcount_t num_words;
wordcount_t num_bytes;
bitcount_t num_n_bits;
uECC_word_t p[uECC_MAX_WORDS];
uECC_word_t n[uECC_MAX_WORDS];
uECC_word_t G[uECC_MAX_WORDS * 2];
uECC_word_t b[uECC_MAX_WORDS];
void (*double_jacobian)(uECC_word_t * X1,
uECC_word_t * Y1,
uECC_word_t * Z1,
uECC_Curve curve);
#if uECC_SUPPORT_COMPRESSED_POINT
void (*mod_sqrt)(uECC_word_t *a, uECC_Curve curve);
#endif
void (*x_side)(uECC_word_t *result, const uECC_word_t *x, uECC_Curve curve);
#if (uECC_OPTIMIZATION_LEVEL > 0)
void (*mmod_fast)(uECC_word_t *result, uECC_word_t *product);
#endif
};

Why do I keep getting "error: variable has incomplete type 'struct intVec'?

I'm doing an assignment for my data structures class and I have very little experience with C structures and C in general.
This is the .h file that I was given to do the assignment:
#ifndef C101IntVec
#define C101IntVec
typedef struct IntVecNode* IntVec;
static const int intInitCap = 4;
int intTop(IntVec myVec);
int intData(IntVec myVec, int i);
int intSize(IntVec myVec);
int intCapacity(IntVec myVec);
IntVec intMakeEmptyVec(void);
void intVecPush(IntVec myVec, int newE);
void intVecPop(IntVec myVec);
#endif
This is the .c implementation that I've made:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "intVec.h"
typedef struct IntVecNode {
int* data;
int sz; // Number of elements that contain data
int capacity; // How much is allocated to the array
} IntVecNode;
typedef struct IntVecNode* IntVec;
//static const int intInitCap = 4;
int intTop(IntVec myVec) {
return *myVec->data;
}
int intData(IntVec myVec, int i) {
return *(myVec->data + i);
}
int intSize(IntVec myVec) {
return myVec->sz;
}
int intCapacity(IntVec myVec) {
return myVec->capacity;
}
IntVec intMakeEmptyVec(void) {
IntVec newVec = malloc(sizeof(struct IntVecNode));
newVec->data = malloc(intInitCap * sizeof(int));
newVec->sz = 0;
newVec->capacity = intInitCap;
return newVec;
}
void intVecPush(IntVec myVec, int newE) {
if (myVec->sz >= myVec->capacity) {
int newCap = myVec->capacity * 2;
myVec->data = realloc(myVec->data, newCap * sizeof(int));
} else {
for (int i = 0; i < myVec->capacity; i++) {
*(myVec->data + i) = *(myVec->data + i + 1);
}
myVec->data = &newE;
}
myVec->sz++;
}
void intVecPop(IntVec myVec) {
for (int i = 0; i < myVec->capacity; i++) {
*(myVec->data - i) = *(myVec->data - i + 1);
}
myVec->sz--;
}
This is the test file:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "intVec.c"
int main() {
struct IntVec v;
v.intVecPush(v,0);
return 0;
}
Every time I run the test file, I get the error:
test.c:7:16: error: variable has incomplete type 'struct IntVec'
struct IntVec v;
^
test.c:7:9: note: forward declaration of 'struct IntVec'
struct IntVec v;
^
1 error generated.
I've tried changing the #include "intVec.c" to "intVec.h" in the test file, however that produces the same error. What would I need to change in order to not get this error?
There is no structure definition struct IntVec.
So the compiler is unable to define the object v
struct IntVec v;
I think you mean
IntVec v;
And this call
v.intVecPush(v,0);
is invalid and does not make sense. I think there should be something like
IntVec v = intMakeEmptyVec();
intVecPush(v,0);
instead of
struct IntVec v;
v.intVecPush(v,0);
Also it is a bad idea to include the whole module in another module. You should place the structure definition in the header and include this header in the compilation unit with main.
That is move these definitions
typedef struct IntVecNode {
int* data;
int sz; // Number of elements that contain data
int capacity; // How much is allocated to the array
} IntVecNode;
typedef struct IntVecNode* IntVec;
in the header.

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