On Mar 29, 2005, at 09:22, Daniel Jacobowitz wrote:
The thing GCC is most likely to do with this code is discard the NULL
check entirely and leave only the oops; the "if (!card)" can not be
reached without passing through "card->amplifier", and a pointer which
is dereferenced can not be NULL in a valid program.
Not true! It is perfectly legal on a large number of platforms to
explicitly mmap something at the address 0, at which point dereferencing
a null pointer is exactly like dereferencing any other pointer on the
heap. Doing so is not recommended except in a few special cases for
emulators and such, but it works to some extent.
Cheers,
Kyle Moffett
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PGP+++ t+(+++) 5 X R? tv-(--) b++++(++) DI+ D+ G e->++++$ h!*()>++$ r
!y?(-)
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