Re: g++ problem with order of evaluation of arguments of delete.

[LIU Hao <lh_mouse@126.com>]

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在 2023/5/4 17:45, Georg-Johann Lay 写道:
> My question: Is this a GCC problem, or a problem with the code and sequence points?

I recommend you learn about smart pointers and stop managing object lifetime by hand.



lh_mouse@lhmouse-xps ~/Desktop $ g++-12 test.cc -fsanitize=address,undefined -g -O2
lh_mouse@lhmouse-xps ~/Desktop $ ./a.out
=================================================================
==75277==ERROR: AddressSanitizer: heap-use-after-free on address 0x602000000030 at pc 0x55629bb062b1 
bp 0x7ffe92a56000 sp 0x7ffe92a55ff0
READ of size 8 at 0x602000000030 thread T0
     #0 0x55629bb062b0 in main /home/lh_mouse/Desktop/test.cc:33
     #1 0x7f6d4aff8d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
     #2 0x7f6d4aff8e3f in __libc_start_main_impl ../csu/libc-start.c:392
     #3 0x55629bb06394 in _start (/home/lh_mouse/Desktop/a.out+0x2394)

0x602000000030 is located 0 bytes inside of 8-byte region [0x602000000030,0x602000000038)
freed by thread T0 here:
     #0 0x7f6d4bc20530 in operator delete(void*, unsigned long) 
../../../../src/libsanitizer/asan/asan_new_delete.cpp:164
     #1 0x55629bb0626d in Lexer::~Lexer() /home/lh_mouse/Desktop/test.cc:20
     #2 0x55629bb0626d in main /home/lh_mouse/Desktop/test.cc:33

previously allocated by thread T0 here:
     #0 0x7f6d4bc1f488 in operator new(unsigned long) 
../../../../src/libsanitizer/asan/asan_new_delete.cpp:95
     #1 0x55629bb061cc in main /home/lh_mouse/Desktop/test.cc:31






-- 
Best regards,
LIU Hao


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