无法解释 LeetCode 上的错误日志 [关闭]答案

【问题标题】：Unable to interpret the error log on LeetCode [closed]无法解释 LeetCode 上的错误日志 [关闭]
【发布时间】：2022-06-15 12:27:47
【问题描述】：

问题 - 在在线编辑器中执行 C++ 程序的问题 - 可能的运行时错误。目标 - 想知道什么样的错误会导致这种错误？场景 - 我正在解决 LeetCode 平台的编辑器上的一个问题（他们在问题旁边提供的用于编写解决方案的编辑器）并且由于一些运行时错误，我收到了这条我无法解释的消息：-

the message that was displayed after the program was run

如果在图片中看不清楚，这里是日志消息的文本：-

=================================================================
==33==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000000a0 at pc 0x0000003479c9 bp 0x7ffd817004f0 sp 0x7ffd817004e8
WRITE of size 4 at 0x6020000000a0 thread T0
    #2 0x7f1c7bd650b2  (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
0x6020000000a0 is located 0 bytes to the right of 16-byte region [0x602000000090,0x6020000000a0)
allocated by thread T0 here:
    #6 0x7f1c7bd650b2  (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)
Shadow bytes around the buggy address:
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff8000: fa fa fd fa fa fa fd fa fa fa fd fa fa fa fd fa
=>0x0c047fff8010: fa fa 00 00[fa]fa fd fa fa fa fd fa fa fa fd fa
  0x0c047fff8020: fa fa 00 fa fa fa fd fa fa fa 00 fa fa fa fd fa
  0x0c047fff8030: fa fa 00 fa fa fa 00 00 fa fa 00 00 fa fa 00 00
  0x0c047fff8040: fa fa 00 00 fa fa fd fa fa fa fd fa fa fa 00 fa
  0x0c047fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8060: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==33==ABORTING

第一行“heap-buffer-overflow”让我知道程序使用了太多的堆内存，因此出现了运行时错误。但我很想知道——这里到底发生了什么？尤其是“Heap left redzone”、“Poisoned by User”、“Array cookie”、“ASan internal” >"、"阴影间隙" - 它们是什么意思？

【问题讨论】：

很可能，您的代码中有越界数组访问。
你想阅读 Asan 手册，试试这个github.com/google/sanitizers/wiki/AddressSanitizer#faq
另见AddressSanitizer, What do these terms mean?
您应该在 gdb 中本地运行代码并将 ASAN 配置为 break on failures，这将告诉您在数组边界之外访问代码中的哪个位置
这真的很有帮助。非常感谢

标签： c++ debugging logging runtime-error heap-memory