C array being overwritten/deleted? very confused - c

Question

I am working on a project in C and it is working great except for one function which seems to be overwriting my array and writing weird numbers such as 1970802352 which keeps count of word occurrences in a file
this is my header file:
#ifndef LIST_H
#define LIST_H
struct Node_{
char* word;
//array holding names of files word occurs in
char **filesIn;
int numFilesIn;
//array holding count of how many times word occured in file
int* occursIn;
struct Node_ *next;
int isHead;
};
typedef struct Node_ Node;
int insert(char *wordToAdd, char *File);
int addOccur(Node *addedTo, char *File);
Node *createNode(char *wordToAdd, char *File);
void destroyNodes();
#endif
and this is the function that keeps overwriting the array:
Node *head;
int insert(char *wordToAdd, char *File){
if(head == NULL){
Node *new;
new = createNode(wordToAdd, File);
new->isHead = 1;
head = new;
return 0;
}
else{
Node *trace;
trace = head;
char *traceWord;
int wordSize;
wordSize = strlen(trace->word);
traceWord = (char*) malloc(wordSize + 1);
strcpy(traceWord, trace->word);
int a =strcmp(wordToAdd, traceWord);
free(traceWord);
if(a == 0){
int b = addOccur(trace, File);
//printf("addOccur returned %d\n", b);
return 0;
}
if(a < 0){
Node *Insert = createNode(wordToAdd, File);
trace->isHead = 0;
Insert->isHead = 1;
Insert->next = trace;
head = Insert;
return 0;
}
else{
Node *backTrace;
backTrace = head;
while(trace->next != NULL){
trace = trace->next;
traceWord = trace->word;
a = strcmp(wordToAdd, traceWord);
if(a < 0){
Node* Insert = createNode(wordToAdd, File);
Insert->next = trace;
backTrace->next = Insert;
return 0;
}
if(a == 0){
addOccur(trace, File);
//free(wordToAdd);
return 0;
}
if(a > 0){
backTrace = trace;
continue;
}
}
Node *Insert = createNode(wordToAdd, File);
trace->next = Insert;
return 0;
}
}
return 1;
}
and the other functions are:
Node* createNode(char *wordToAdd, char *File){
Node *new;
new = (Node*)malloc(sizeof(Node));
memset(new, 0, sizeof(Node));
new->word = wordToAdd;
char **newArray;
newArray = (char**)malloc(sizeof(char*));
newArray[0] = File;
new->filesIn = newArray;
int a[1];
a[0] = 1;
new->occursIn = a;
//new->occursIn[0] = 1;
new->numFilesIn = 1;
return new;
}
int addOccur(Node *addedTo, char *File){
char **fileList = addedTo->filesIn;
char *fileCheck;
int i = 0;
int fileNums = addedTo->numFilesIn;
for(i = 0; i < fileNums; i++){
fileCheck = fileList[i];
if(strcmp(fileCheck, File) == 0){
int *add1;
add1 = addedTo->occursIn;
int j = add1[i];
j++;
add1[i] = j;
return 0;
}
}
int numberOfFilesIn;
numberOfFilesIn = addedTo->numFilesIn;
char **newList = (char**)malloc(sizeof(char*) * numberOfFilesIn + sizeof(char*));
i = 0;
char *dest;
char *src;
for(i = 0; i < numberOfFilesIn; i++){
src = fileList[i];
int len;
len = strlen(src);
dest = (char*)malloc(sizeof(char) * (len + 1));
strcpy(dest, src);
newList[i] = dest;
}
int len2;
len2 = strlen(File);
newList[i] = File;
free(fileList);
int r = addedTo->numFilesIn;
r++;
addedTo->numFilesIn = r;
addedTo->filesIn = newList;
i = 0;
int *g;
g = addedTo->occursIn;
int count2;
count2 = addedTo->numFilesIn;
count2++;
int a[count2];
for(i = 0; i < count2 -1; i++){
a[i] = g[i];
}
a[count2 - 1] = 1;
return 0;
}
When going to gdb i notice that the value of
head->occursIn[0]
changes after the line
wordSize = strlen(trace->word);
and I have no clue why.

Answer 1

In your CreateNode() function, you are not allocating storage for the occursIn array. You are simply declaring a local array within the function and then assigning the occursIn pointer:
int a[1];
a[0] = 1;
new->occursIn = a;
The array a[1] goes away when the createNode function returns, so at that point your occursIn pointer is pointing to a value that is subject to being overwritten.
And even if the storage was allocated correctly in createNode, you've set a fixed size for the array but your whole strategy depends on that array having an element for each file; and in addOccurs you don't do anything to allocate a new larger array for a new file.
You may want to re-evaluate your strategy and switch to using lists instead of arrays.