Stack Overflow error : Passing struct to function vc++ - pointers

Question

I am working with VC++ for some months now. I have never come across 'Stack Overflow' error until today when I try to pass a structure to function.
This is my code:
int bReadFileData(string sFile, struct FILE_DATA *File_Data);
const int MAX_CRASH_FILE_SIZE = 100000;
struct FILE_DATA
{
int SIZE;
int GOOD[MAX_CRASH_FILE_SIZE];
int BAD[MAX_CRASH_FILE_SIZE];
};
int bReadFileData(string sFile, struct FILE_DATA *File_Data)
{
File_Data->SIZE = 0;
if(PathFileExists(Convert.StringToCstring(sFile)) == 1)
{
string sLine = "";
int iLine = 0;
std::ifstream File(sFile);
while(getline(File, sLine))
{
if(sLine.find(":") != std::string::npos)
{
File_Data->CRASH_VALUES[iLine] = sLine.substr(0, sLine.find(":"));
File_Data->CRASH_VALUES[iLine] = sLine.substr(sLine.find(":") + 1, sLine.length());
}
else
{
File_Data->CRASH_VALUES[iLine] = (sLine);
}
iLine++;
}
File_Data->SIZE = iLine;
}
return 1;
}
`
From main function I am calling below method.
void ReadFiles()
{
FILE_DATA Files[3];
bReadFileData("C:\\Test1.txt", &Files[0]);
bReadFileData("C:\\Test2.txt", &Files[1]);
bReadFileData("C:\\Test3.txt", &Files[2]);
}
Is there any thing wrong in this code? Why stack overflow error is thrown(as soon as it enter ReadFiles()?

Answer 1

Why stack overflow error is thrown(as soon as it enter ReadFiles()?
That's because FILE_DATA[3] allocates too much bytes for stack memory. The size of stack memory is around 1Mb by default, while size of FILE_DATA[3] is around 2.4Mb (~ 800,000 x 3 bytes).
If you use the struct with large size, try to use heap memory as follows:
void ReadFiles()
{
FILE_DATA* Files = new FILE_DATA[3];
bReadFileData("C:\\Test1.txt", &Files[0]);
bReadFileData("C:\\Test2.txt", &Files[1]);
bReadFileData("C:\\Test3.txt", &Files[2]);
delete [] Files;
Files = nullptr;
}

Answer 2

This is not just bad, but terrible design. You should:
Use vector for GOOD and BAD
Use vector.push_back instead of File_Data->CRASH_VALUES[iLine] assignment.
Use dynamic allocation (if you don't use vector). If you must use dynamic allocation, I recommend using make_unique (C++11/14) instead of new, like this:
void ReadFiles()
{
auto Files = std::make_unique<FILE_DATA[]>(2);
bReadFileData("C:\\Test1.txt", &Files[0]);
bReadFileData("C:\\Test2.txt", &Files[1]);
bReadFileData("C:\\Test3.txt", &Files[2]);
// delete [] Files; - DONT NEED
// Files = nullptr;
}
If you can simply use vector, you can have this:
void ReadFiles()
{
FILE_DATA Files[3];
...