我在解释和调试刚从在线课程（nand2tetris）完成的C程序的valgrind输出时遇到问题，该课程现在可以正常运行。这是源代码的链接：https://github.com/salario/nand2tetris/blob/master/assembler.c
这是valgrind的输出，显示可能丢失的内存泄漏消息。我使用以下命令进行了编译：{{1}}
$ valgrind --leak-check=full ./assembler Pong.asm
==35574== Memcheck, a memory error detector
==35574== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==35574== Using Valgrind-3.16.0.GIT and LibVEX; rerun with -h for copyright info
==35574== Command: ./assembler Pong.asm
==35574==
==35574==
==35574== HEAP SUMMARY:
==35574== in use at exit: 13,932 bytes in 159 blocks
==35574== total heap usage: 1,096 allocs, 937 frees, 137,988 bytes allocated
==35574==
==35574== 24 bytes in 1 blocks are possibly lost in loss record 6 of 37
==35574== at 0x1002B5E51: malloc_zone_calloc (in /usr/local/Cellar/valgrind/HEAD-36f444c/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==35574== by 0x100877541: NXMapInsert (in /usr/lib/libobjc.A.dylib)
==35574== by 0x100877625: _NXMapRehash(_NXMapTable*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x10087757C: NXMapInsert (in /usr/lib/libobjc.A.dylib)
==35574== by 0x10087723D: _mapStrHash(_NXMapTable*, void const*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x100876FFC: _getObjc2ProtocolList(header_info const*, unsigned long*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x10087596E: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1008862D0: unmap_image (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1001AE5A5: dyld::notifyBatchPartial(dyld_image_states, bool, char const* (*)(dyld_image_states, unsigned int, dyld_image_info const*), bool, bool) (in /usr/lib/dyld)
==35574== by 0x1001AE746: dyld::registerObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) (in /usr/lib/dyld)
==35574== by 0x10044FAD0: _dyld_objc_notify_register (in /usr/lib/system/libdyld.dylib)
==35574== by 0x100874DAF: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574==
==35574== 264 bytes in 3 blocks are possibly lost in loss record 30 of 37
==35574== at 0x1002B5C90: calloc (in /usr/local/Cellar/valgrind/HEAD-36f444c/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==35574== by 0x100875049: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1008862D0: unmap_image (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1001AE5A5: dyld::notifyBatchPartial(dyld_image_states, bool, char const* (*)(dyld_image_states, unsigned int, dyld_image_info const*), bool, bool) (in /usr/lib/dyld)
==35574== by 0x1001AE746: dyld::registerObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) (in /usr/lib/dyld)
==35574== by 0x10044FAD0: _dyld_objc_notify_register (in /usr/lib/system/libdyld.dylib)
==35574== by 0x100874DAF: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1003D1F38: _os_object_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1003DE0E7: libdispatch_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1002C1790: libSystem_initializer (in /usr/lib/libSystem.B.dylib)
==35574== by 0x1001C41E2: ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) (in /usr/lib/dyld)
==35574== by 0x1001C45ED: ImageLoaderMachO::doInitialization(ImageLoader::LinkContext const&) (in /usr/lib/dyld)
==35574==
==35574== 2,064 bytes in 1 blocks are possibly lost in loss record 36 of 37
==35574== at 0x1002B58AA: malloc_zone_malloc (in /usr/local/Cellar/valgrind/HEAD-36f444c/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==35574== by 0x1008770B5: getProtocol(char const*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x10087596E: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1008862D0: unmap_image (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1001AE5A5: dyld::notifyBatchPartial(dyld_image_states, bool, char const* (*)(dyld_image_states, unsigned int, dyld_image_info const*), bool, bool) (in /usr/lib/dyld)
==35574== by 0x1001AE746: dyld::registerObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) (in /usr/lib/dyld)
==35574== by 0x10044FAD0: _dyld_objc_notify_register (in /usr/lib/system/libdyld.dylib)
==35574== by 0x100874DAF: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1003D1F38: _os_object_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1003DE0E7: libdispatch_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1002C1790: libSystem_initializer (in /usr/lib/libSystem.B.dylib)
==35574== by 0x1001C41E2: ImageLoaderMachO::doModInitFunctions(ImageLoader::LinkContext const&) (in /usr/lib/dyld)
==35574==
==35574== 2,064 bytes in 1 blocks are possibly lost in loss record 37 of 37
==35574== at 0x1002B58AA: malloc_zone_malloc (in /usr/local/Cellar/valgrind/HEAD-36f444c/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==35574== by 0x10087801E: NXMapRemove (in /usr/lib/libobjc.A.dylib)
==35574== by 0x100877EA5: search_method_list(method_list_t const*, objc_selector*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1008760DD: _getObjc2MessageRefs(header_info const*, unsigned long*) (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1008862D0: unmap_image (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1001AE5A5: dyld::notifyBatchPartial(dyld_image_states, bool, char const* (*)(dyld_image_states, unsigned int, dyld_image_info const*), bool, bool) (in /usr/lib/dyld)
==35574== by 0x1001AE746: dyld::registerObjCNotifiers(void (*)(unsigned int, char const* const*, mach_header const* const*), void (*)(char const*, mach_header const*), void (*)(char const*, mach_header const*)) (in /usr/lib/dyld)
==35574== by 0x10044FAD0: _dyld_objc_notify_register (in /usr/lib/system/libdyld.dylib)
==35574== by 0x100874DAF: map_images_nolock (in /usr/lib/libobjc.A.dylib)
==35574== by 0x1003D1F38: _os_object_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1003DE0E7: libdispatch_init (in /usr/lib/system/libdispatch.dylib)
==35574== by 0x1002C1790: libSystem_initializer (in /usr/lib/libSystem.B.dylib)
==35574==
==35574== LEAK SUMMARY:
==35574== definitely lost: 0 bytes in 0 blocks
==35574== indirectly lost: 0 bytes in 0 blocks
==35574== possibly lost: 4,416 bytes in 6 blocks
==35574== still reachable: 9,516 bytes in 153 blocks
==35574== suppressed: 0 bytes in 0 blocks
==35574== Reachable blocks (those to which a pointer was found) are not shown.
==35574== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==35574==
==35574== For lists of detected and suppressed errors, rerun with: -s
==35574== ERROR SUMMARY: 4 errors from 4 contexts (suppressed: 4 from 4)
我已经阅读了valgrind的文档，并且尝试对源代码进行许多不同的更改，但似乎无法解决这些问题。如果有人可以通过查看此错误和消息来源并让我知道您是否可以发现可能的问题，将我的方向指向正确，我将不胜感激。
此外，我尝试了其他推荐的valgrind标志，但无法弄清楚如何获取输出以显示源文件中的行号。另外，所有可能丢失的内存错误详细信息都没有引用我的任何函数或文件，因此调试尤其具有挑战性。
答案 0 :(得分：0)
这些内存泄漏来自运行时，例如/usr/lib/system/libdispatch.dylib，/usr/lib/libSystem.B.dylib，/usr/lib/dyld。
我在Linux（valgrind --leak-check=full ./a.out Pong.asm）上运行了您的程序：
==102140== Memcheck, a memory error detector
==102140== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==102140== Using Valgrind-3.16.1 and LibVEX; rerun with -h for copyright info
==102140== Command: ./a.out Pong.asm
==102140==
==102140==
==102140== HEAP SUMMARY:
==102140== in use at exit: 0 bytes in 0 blocks
==102140== total heap usage: 927 allocs, 927 frees, 121,200 bytes allocated
==102140==
==102140== All heap blocks were freed -- no leaks are possible
==102140==
==102140== For lists of detected and suppressed errors, rerun with: -s
==102140== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
程序中没有内存泄漏，只有加载程序/运行时泄漏内存。