Messages in this thread | | | Subject | Re: [PATCH] treewide: Replace zero-length arrays with flexible-array member | From | "Gustavo A. R. Silva" <> | Date | Tue, 11 Feb 2020 14:16:19 -0600 |
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On 2/11/20 13:35, Kees Cook wrote: > On Tue, Feb 11, 2020 at 11:41:26AM -0600, Gustavo A. R. Silva wrote: >> The current codebase makes use of the zero-length array language >> extension to the C90 standard, but the preferred mechanism to declare >> variable-length types such as these ones is a flexible array member[1][2], >> introduced in C99: >> >> struct foo { >> int stuff; >> struct boo array[]; >> }; >> >> By making use of the mechanism above, we will get a compiler warning >> in case the flexible array does not occur last in the structure, which >> will help us prevent some kind of undefined behavior bugs from being >> unadvertenly introduced[3] to the codebase from now on. > > Is there a compiler warning we can enable to avoid new 0-byte arrays > from entering the kernel source tree? I can only find "-pedantic" which > enables way too many other checks. >
Months ago, I only found -pedantic, too. And we definitely don't want to use it for this. :/
-- Gustavo
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