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#include "stdio.h"
#include "stdlib.h"
#include "string.h"
void Test(int* value)
{
delete[] value;
value = NULL;
value = new int[10];
for(int i=0;i<10;i++)
value[i] = 10+i;
}
int main()
{
int* value = new int[5];
for(int i=0;i<5;i++)
{
value[i] = i;
printf("%d\t",value[i]);
}
Test(value);
printf("\n");
for(int i=0;i<10;i++)
printf("%d\t",value[i]);
if (value)
{
delete[] value;
value = NULL;
}
return 0;
}
#ifndef MEMCHECK_H
#define MEMCHECK_H
#include <cstddef> // for size_t
// Hijack the new operator (both scalar and array versions)
void* operator new(std::size_t, const char*, long);
void* operator new[](std::size_t, const char*, long);
#define new new (__FILE__, __LINE__)
extern bool traceFlag;
#define TRACE_ON() traceFlag = true
#define TRACE_OFF() traceFlag = false
extern bool activeFlag;
#define MEM_ON() activeFlag = true
#define MEM_OFF() activeFlag = false
#endif
MemCheck.cpp:
#include <cstdio>
#include <cstdlib>
#include <cassert>
using namespace std;
#undef new
// Global flags set by macros in MemCheck.h
bool traceFlag = true;
bool activeFlag = false;
namespace
{
// Memory map entry type
struct Info
{
void* ptr;
const char* file;
long line;
};
// Memory map data
const size_t MAXPTRS = 10000u;
Info memMap[MAXPTRS];
size_t nptrs = 0;
// Searches the map for an address
int findPtr(void* p)
{
for (int i = 0; i < nptrs; ++i)
{
if (memMap[i].ptr == p)
{
return i;
}
}
return -1;
}
void delPtr(void* p)
{
int pos = findPtr(p);
assert(p >= 0);
// Remove pointer from map
for (size_t i = pos; i < nptrs-1; ++i)
{
memMap[i] = memMap[i+1];
}
--nptrs;
}
// Dummy type for static destructor
struct Sentinel
{
~Sentinel()
{
if (nptrs > 0)
{
printf("Leaked memory at:\n");
for (size_t i = 0; i < nptrs; ++i)
{
printf("\t%p (file: %s, line %ld)\n",
memMap[i].ptr, memMap[i].file, memMap[i].line);
}
}
else
{
printf("No user memory leaks!\n");
}
}
};
// Static dummy object
Sentinel s;
} // End anonymous namespace
// Overload scalar new
void* operator new(size_t siz, const char* file,
long line)
{
void* p = malloc(siz);
if (activeFlag)
{
if (nptrs == MAXPTRS)
{
printf("memory map too small (increase MAXPTRS)\n");
exit(1);
}
memMap[nptrs].ptr = p;
memMap[nptrs].file = file;
memMap[nptrs].line = line;
++nptrs;
}
if (traceFlag)
{
printf("Allocated %u bytes at address %p ", siz, p);
printf("(file: %s, line: %ld)\n", file, line);
}
return p;
}
// Overload array new
void* operator new[](size_t siz, const char* file,
long line)
{
printf("new[]\n");
return operator new(siz, file, line);
}
// Override scalar delete
void operator delete(void* p)
{
if (findPtr(p) >= 0)
{
free(p);
assert(nptrs > 0);
delPtr(p);
if (traceFlag)
{
printf("Deleted memory at address %p\n", p);
}
}
else if (!p && activeFlag)
{
printf("Attempt to delete unknown pointer: %p\n", p);
}
}
// Override array delete
void operator delete[](void* p)
{
printf("delete[]\n");
operator delete(p);
}
console.cpp:
#include "stdio.h"
#include "stdlib.h"
#include "string"
#include "MemCheck.h" // Must appear last!
void Test(int* value)
{
delete[] value;
value = NULL;
value = new int[10];
for(int i=0;i<10;i++)
value[i] = 10+i;
}
void TestStr(char* name)
{
delete[] name;
name = NULL;
name = new char[10];
strcpy(name, "zengraoli");
}
int main()
{
TRACE_OFF();
MEM_ON();
int* value = new int[5];
for(int i=0;i<5;i++)
{
value[i] = i;
printf("%d\t",value[i]);
}
Test(value);
for(int i=0;i<10;i++)
printf("%d\t",value[i]);
if (value)
{
delete[] value;
value = NULL;
}
char* name = new char[5];
strcpy(name, "zeng");
printf("current str value is : %s\n", name);
TestStr(name);
printf("current str value is : %s\n", name);
if (name)
{
delete[] name;
name = NULL;
}
MEM_OFF();
return 0;
}
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
void Test(int** value)
{
delete[] (*value);
*value = NULL;
*value = new int[10];
for(int i=0;i<10;i++)
(*value)[i] = 10+i;
}
int main()
{
int* value = new int[5];
for(int i=0;i<5;i++)
{
value[i] = i;
printf("%d\t",value[i]);
}
Test(&value);
printf("\n");
for(int i=0;i<10;i++)
printf("%d\t",value[i]);
if (value)
{
delete[] value;
value = NULL;
}
return 0;
}
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