On 6/5/18, Martin Sebor <mse...@gmail.com> wrote: > The attached patch adds basic support for handling strnlen > as a built-in function. It touches the strlen pass where > it folds constant results of the function, and builtins.c > to add simple support for expanding strnlen calls with known > results. It also changes calls.c to detect excessive bounds > to the function and unsafe calls with arguments declared > attribute nonstring. > > A side-effect of the strlen change I should call out is that > strlen() calls to all zero-length arrays that aren't considered > flexible array members (i.e., internal members or non-members) > are folded into zero. No warning is issued for such invalid > uses of zero-length arrays but based on the responses to my > question Re: aliasing between internal zero-length-arrays and > other members(*) it sounds like one would be appropriate. > I will see about adding one in a separate patch. > > Martin > > [*] https://gcc.gnu.org/ml/gcc/2018-06/msg00046.html >
I see stuff in the patch mentioning the library version of strnlen; have you tested on platforms both with and without strnlen in their libcs? The gnulib documentation lists these platforms as having missing or buggy strnlens: This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, AIX 4.3.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, mingw, Interix 3.5. This function is buggy on some platforms: AIX 4.3. https://www.gnu.org/software/gnulib/manual/html_node/strnlen.html
