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From: stripes@pix.com (Josh Osborne)
Subject: Re: Segmentation faults
Message-ID: <BzMFF4.Aut@pix.com>
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Organization: Pix Technologies -- The company with no adult supervision
References: <1gricmINNsl@ub.d.umn.edu> <1992Dec18.134225.20548@Logix.DE> <veit.724925472@du9ds3>
Date: Mon, 21 Dec 1992 18:01:51 GMT
Lines: 22
In article <veit.724925472@du9ds3> veit@du9ds3.fb9dv.uni-duisburg.de writes:
[...]
>This is a real problem where sizeof(int) != sizeof(char*), for instance with
>Turbo C or Microsoft C or similar 16bit junk. But if you compile this
>with a 32bit K&R compiler, and sizeof(int)==sizeof(char*) (=4), it won't see
>a difference, because it will just take 32bit from the parameter stack
>and push it as a 32bit argument to printf.
(which masks many bugs, which will show up on, say the Alpha)
>The compiler cannot find out the real expected type (it cannot do parsing
>of the format string in general!).
Not in general, but gcc CAN verify printf/scanf style args and parms as
long as the format string is a constant. See __attribute__ in the gcc
manual.
--
stripes@pix.com "Security for Unix is like
Josh_Osborne@Real_World,The Multitasking for MS-DOS"
"The dyslexic porgramer" - Kevin Lockwood
We all agree on the necessity of compromise. We just can't agree on
when it's necessary to compromise. - Larry Wall