The English introduction is placed below the Chinese version.
memleak.h是一个轻量级的内存泄漏检测库，通过在内部实现一个内存池，实现自己的malloc、calloc、realloc、free、new和delete函数并重载标准库的函数，实现了内存泄漏检测功能，支持c和c++调用。
只需要在开头导入memleak.h，并调用setup_mem和set_leak_detect函数，就能启用退出程序时输出内存泄漏信息。
setup_mem函数还能设置内存大小，模拟小内存环境，测试程序能否处理内存不足的情况。
此外，库还提供了show_mem_info()和dump_mem_to_file()，用于调试内存。
和Valgrind、Dr.Memory等复杂工具不同，memleak.h库只需要简单地嵌入C/C++代码中，使用便捷。
memleak.h支持单头文件(在single_header_version目录)、静态链接和动态链接3种方式的导入。
直接复制single_header_version目录中的memleak.h到自己项目的目录下，即可。仅支持C++项目。
静态链接同时支持C和C++项目。
首先编译memleak库的源代码memleak.cpp:
g++ -c memleak.cpp -o bin/memleak_static.o -O2 -Wall -Iinclude然后编译C文件生成目标文件(也可以用C++):
gcc -c memleak_ctest.c -o bin/memleak_ctest.o -O2 -Wall -Iinclude最后链接。由于gcc不支持c++编译的memleak_static.o的格式，这一步需要用g++而不是gcc。
g++ bin/memleak_ctest.o bin/memleak_static.o -o bin/memleak_ctest_static -s -Wall -Iinclude动态链接也同时支持C和C++项目。
首先编译出DLL文件(linux下用.so):
g++ memleak.cpp -o bin/memleak.dll -s -O2 -Wall -DMEMLEAK_DLL_EXPORT -shared -Wl,--out-implib,lib\libmemleak.a -Iinclude然后链接这个DLL:
gcc memleak_ctest.c -o bin/memleak_ctest -s -Wall -Iinclude -Llib -lmemleak完整的编译和链接这个库的示例，详见项目中的文件build.bat。
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void setup_mem(size_t size,size_t mcb_count,unsigned char initVal):
size: 总内存大小。
mcb_count: 能分配的最多内存块数量，为0则表示用默认值(8192)。
initVal: 内存初始化的字节，一般为0，但如果要调试使用未初始化变量，建议用0xcd等特殊值。 -
void setup_mem_noinit(size_t size,size_t mcb_count):
这个版本不初始化内存，参数用法和setup_mem相同。 -
void set_leak_detect(bool enabled):
设置程序退出时是否显示内存泄漏信息，如果为true，则显示。
在C中使用时需要导入stdbool.h。 -
void shutdown():
释放调用setup_mem()时分配的内存，关闭自定义的内存分配器，以及泄漏检测。 -
void show_mem_info():
在标准输出显示当前内存信息，如分配的内存块数量，以及大小等。格式示例：
Total: 1048576B Used: 140B Free: 1048436B
Start - Size
0. 0 - 12
1. 12 - 40
2. 52 - 4
3. 56 - 80
4. 136 - 4
5 memory blocks.
void dump_mem_to_file(const char *filename)导出全部内存到二进制文件filename，文件大小为调用setup_mem()时申请的内存大小。
完整的使用示例参见memleak_ctest.c和memleak_test.cpp。对于memleak.h库的内部实现，如MemMgr内存池类的使用示例，参见memmgr_test.cpp。
对于C++，memleak.h会重载默认的operator new、operator delete和new[]、delete[]，以便于使整个STL，如vector、map都使用自定义的new,delete分配内存。
对于C，memleak.h会用宏定义重载malloc,calloc,realloc,free,以及底层调用了malloc的strdup,wcsdup函数。
未启用(未调用setup_mem())时，重载的内存分配函数会直接调用标准库的函数，如malloc调用std::malloc，不影响正常的内存分配。
启用(调用setup_mem())之后，重载的函数会调用自定义的内存分配器。调用shutdown()即可恢复为用标准库的函数。
可以用宏DISABLE_OVERWRITING_STD避免重载标准库。
如果定义了MEMLEAK_MACRO_WITH_ARG，则会定义带参数的宏，如#define malloc(size) _override_std_malloc((size))，否则用默认的#define malloc _override_std_malloc。
如果定义了MEMLEAK_DLL_EXPORT，则会导出函数到动态库。
此外，如果要利用memleak.h的内部实现，如MemMgr类等，需要定义宏MEMLEAK_NO_EXTERNAL，也就是不用外部的函数。memleak.h的内部实现存放在memleak命名空间中，可以在C++代码中导入。
自定义的malloc,calloc,realloc,free等函数作为标准库函数的重载，与标准库函数的行为一致。
自定义的malloc,calloc,realloc函数在内存不足时返回nullptr。
如果realloc和free传入了错误的内存地址，则会抛出ReallocError异常，对于free则是抛出DoubleFreeError。在C++中可以捕获这两个异常，在C中则会直接终止程序。
malloc和calloc传入的总大小如果是0，则会返回nullptr。realloc如果传入的大小是0，则会释放传入的内存指针。
free支持传入nullptr作为参数。
memleak.h is a lightweight memory leak detection library. By implementing an internal memory pool and overriding standard library functions such as malloc, calloc, realloc, free, new, and delete, it provides memory leak detection functionality and supports both C and C++ calls.
Simply import memleak.h at the beginning of your code and call the setup_mem and set_leak_detect functions to enable the output of memory leak information upon program exit.
The setup_mem function can also set the memory size to simulate a low-memory environment, testing whether the program can handle insufficient memory situations.
Additionally, the library provides show_mem_info() and dump_mem_to_file() for debugging memory.
Unlike complex tools such as Valgrind and Dr. Memory, the memleak.h library can be easily embedded into C/C++ code, making it convenient to use.
memleak.h supports three import methods: single-header file (in the single_header_version directory), static linking, and dynamic linking.
Simply copy the memleak.h file from the single_header_version directory to your project directory. This method only supports C++ projects.
Static linking supports both C and C++ projects.
First, compile the source code of the memleak library, memleak.cpp:
g++ -c memleak.cpp -o bin/memleak_static.o -O2 -Wall -IincludeThen, compile the C file to generate the object file (C++ can also be used):
gcc -c memleak_ctest.c -o bin/memleak_ctest.o -O2 -Wall -IincludeFinally, link the files. Since gcc does not support the format of memleak_static.o compiled with C++, this step requires g++ instead of gcc.
g++ bin/memleak_ctest.o bin/memleak_static.o -o bin/memleak_ctest_static -s -Wall -IincludeDynamic linking also supports both C and C++ projects.
First, compile the DLL file (use .so on Linux):
g++ memleak.cpp -o bin/memleak.dll -s -O2 -Wall -DMEMLEAK_DLL_EXPORT -shared -Wl,--out-implib,lib\libmemleak.a -IincludeThen, link this DLL:
gcc memleak_ctest.c -o bin/memleak_ctest -s -Wall -Iinclude -Llib -lmemleakFor a complete example of compiling and linking this library, refer to the build.bat file in the project.
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void setup_mem(size_t size, size_t mcb_count, unsigned char initVal):
size: Total memory size.
mcb_count: Maximum number of memory blocks that can be allocated. If set to 0, the default value (8192) is used.
initVal: Byte used to initialize memory. Typically 0, but if debugging uninitialized variables, it is recommended to use a special value like0xcd. -
void setup_mem_noinit(size_t size, size_t mcb_count):
This version does not initialize memory. The parameters are the same assetup_mem. -
void set_leak_detect(bool enabled):
Sets whether to display memory leak information upon program exit. Iftrue, it will display.
In C,stdbool.hneeds to be imported. -
void shutdown():
Releases the memory allocated bysetup_mem(), closes the custom memory allocator, and disables leak detection. -
void show_mem_info():
Displays current memory information on standard output, such as the number of allocated memory blocks and their sizes. Example format:
Total: 1048576B Used: 140B Free: 1048436B
Start - Size
0. 0 - 12
1. 12 - 40
2. 52 - 4
3. 56 - 80
4. 136 - 4
5 memory blocks.
void dump_mem_to_file(const char *filename):
Exports all memory to a binary file namedfilename, with the file size equal to the memory size requested when callingsetup_mem().
For complete usage examples, refer to memleak_ctest.c and memleak_test.cpp. For internal implementation details of the memleak.h library, such as examples of using the MemMgr memory pool class, see memmgr_test.cpp.
For C++, memleak.h overloads the default operator new, operator delete, and new[], delete[] to ensure that the entire STL, such as vector and map, uses the custom new and delete for memory allocation.
For C, memleak.h uses macro definitions to overload malloc, calloc, realloc, free, as well as the strdup and wcsdup functions that internally call malloc.
When not enabled (i.e., setup_mem() not called), the overloaded memory allocation functions will directly call the standard library functions, such as malloc calling std::malloc, without affecting normal memory allocation.
Once enabled (after calling setup_mem()), the overloaded functions will call the custom memory allocator. Calling shutdown() will revert to using the standard library functions.
You can use the macro DISABLE_OVERWRITING_STD to avoid overloading the standard library.
If MEMLEAK_MACRO_WITH_ARG is defined, it will define macros with parameters, such as #define malloc(size) _override_std_malloc((size)); otherwise, it will use the default #define malloc _override_std_malloc.
If MEMLEAK_DLL_EXPORT is defined, it will export functions to the dynamic library.
Additionally, if you want to utilize the internal implementation of memleak.h, such as the MemMgr class, you need to define the macro MEMLEAK_NO_EXTERNAL, meaning no external functions will be used. The internal implementation of memleak.h is stored in the memleak namespace, which can be imported in C++ code.
The custom malloc, calloc, realloc, free, and other functions behave consistently with the standard library functions.
The custom malloc, calloc, and realloc functions return nullptr when memory is insufficient.
If realloc and free are passed incorrect memory addresses, a ReallocError exception will be thrown, and for free, a DoubleFreeError will be thrown. In C++, these two exceptions can be caught, while in C, the program will terminate directly.
If the total size passed to malloc and calloc is 0, they will return nullptr. If realloc is passed a size of 0, it will free the passed memory pointer.
free supports passing nullptr as a parameter.