Debug new
Encyclopedia
Debug_new refers to a technique in C++
to overload and/or redefine operator new
and operator delete
in order to intercept the memory allocation and deallocation calls, and thus debug a program for memory usage. It often involves defining a macro named DEBUG_NEW, and makes new become something like new(__FILE__, __LINE__) to record the file/line information on allocation. Microsoft Visual C++
uses this technique in its Microsoft Foundation Classes. There are some ways to extend this method to avoid using macro redefinition while still able to display the file/line information on some platforms.
There are many inherent limitations to this method. It applies only to C++, and cannot catch memory leaks by C
functions like malloc
. However, it can be very simple to use and also very fast, when compared to some more complete memory debugger
solutions.
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
to overload and/or redefine operator new
Operator new
In the C++ programming language, as well as in many C++-based languages, new is a language construct that dynamically allocates memory on the heap and initialises the memory using the constructor. Except for a form called the "placement new", new attempts to allocate enough memory on the heap for...
and operator delete
Operator delete
In the C++ programming language, the delete operator calls the destructor of the given argument, and returns memory allocated by new back to the heap. A call to delete must be made for every call to new to avoid a memory leak. After calling delete the memory object pointed to is invalid and...
in order to intercept the memory allocation and deallocation calls, and thus debug a program for memory usage. It often involves defining a macro named DEBUG_NEW, and makes new become something like new(__FILE__, __LINE__) to record the file/line information on allocation. Microsoft Visual C++
Visual C++
Microsoft Visual C++ is a commercial , integrated development environment product from Microsoft for the C, C++, and C++/CLI programming languages...
uses this technique in its Microsoft Foundation Classes. There are some ways to extend this method to avoid using macro redefinition while still able to display the file/line information on some platforms.
There are many inherent limitations to this method. It applies only to C++, and cannot catch memory leaks by C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
functions like malloc
Malloc
C dynamic memory allocation refers to performing dynamic memory allocation in the C via a group of functions in the C standard library, namely malloc, realloc, calloc and free....
. However, it can be very simple to use and also very fast, when compared to some more complete memory debugger
Memory debugger
A memory debugger is a programming tool for finding memory leaks and buffer overflows. These are due to bugs related to the allocation and deallocation of dynamic memory. Programs written in languages that have garbage collection, such as managed code, might also need memory debuggers, e.g...
solutions.