remembered you came across a LTO issue when using 4.8 some days ealier.
--
Best Regards,
xunxun
be released?
--
Best Regards,
xunxun
于 2011/10/22 13:13, xunxun 写道:
Hi, all
It seems that gcc's auto-omit-frame-pointer has other problems.
The example is from mingw bug tracker:
http://sourceforge.net/tracker/?func=detail&aid=3426555&group_id=2435&atid=102435
g++ -O3 main.cpp running will c
running no crash.
g++ -O3 -fno-omit-frame-pointerrunning no crash.
I don't know in the end which optimize option defaultly contains
this switch "-fomit-frame-pointer" on i686-pc-mingw32 or x86_64-w64-mingw32?
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Best Regards,
xunxun
#include
typedef void (*Func)
ase candidate on
> x86_64-linux and i686-linux. Please test it and report any issues to
> bugzilla.
>
> If all goes well, I'd like to release 4.6.2 in the middle of the next week.
>
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Best Regards,
xunxun
ide test-code with, or without zero-ing ebp.
>
>
> We probably have a difference in build or run environment. I've
> double-checked with another machine and can get the same crash in
> longjmp when running the test executable on both WinXP and Win2k, but
> not on Win7. So it looks like Microsoft may have changed this "feature"
> somewhere between WinXP and Win7.
>
> The msvcrt implementation of longjmp (or at least the one I'm looking
> at) does a ebp based access using the saved value of ebp. Here's the
> relevant disassembly of longjmp:
>
> 0x7801e6f3 in longjmpex () from C:\WINNT\system32\msvcrt.dll
> (gdb) disas
> Dump of assembler code for function longjmpex:
> 0x7801e6ef <+0>: mov 0x4(%esp),%ebx
> => 0x7801e6f3 <+4>: mov (%ebx),%ebp
> ...
> 0x7801e73d <+78>: call 0x7800bd5e
> ...
> 0x7800bd5e <+56>: push %ebx
> 0x7800bd5f <+57>: push %ecx
> 0x7800bd60 <+58>: mov $0x7803dc64,%ebx
> => 0x7800bd65 <+63>: mov 0x8(%ebp),%ecx
>
> It crashes on the access of 0x8(%ebp). Those are the only 2 places
> where this version of longjmp touches ebp. Is it possible to force a
> stackframe by just adding a suitable attribute to either the setjmp
> function prototype, or the function which calls setjmp?
>
> Bob
>
--
Best Regards,
xunxun
