Ping: https://gcc.gnu.org/ml/gcc-patches/2018-02/msg00076.html
On 02/01/2018 04:45 PM, Martin Sebor wrote:
The previous patch didn't resolve all the false positives in the Linux kernel. The attached is an update that fixes the remaining one having to do with multidimensional array members: struct S { char a[2][4]; }; void f (struct S *p, int i) { strcpy (p->a[0], "012"); strcpy (p->a[i] + 1, p->a[0]); // false positive here } In the process of fixing this I also made a couple of minor restructuring changes to the builtin_memref constructor to in order to make the code easier to follow: I broke it out into a couple of helper functions and called those. As with the first revision of the patch, this one is also meant to be applied on top of https://gcc.gnu.org/ml/gcc-patches/2018-01/msg01488.html Sorry about the late churn. Even though I tested the original implementation with the Linux kernel the bugs were only exposed non-default configurations that I didn't build. Jakub, you had concerns about the code in the constructor and about interpreting the offsets in the diagnostics. I tried to address those in the patch. Please review the changes and let me know if you have any further comments. Thanks Martin On 01/30/2018 04:19 PM, Martin Sebor wrote:Testing GCC 8 with recent Linux kernel sources has uncovered a bug in the handling of arrays of arrays by the -Wrestrict checker where it fails to take references to different array elements into consideration, issuing false positives. The attached patch corrects this mistake. In addition, to make warnings involving excessive offset bounds more meaningful (less confusing), I've made a cosmetic change to constrain them to the bounds of the accessed object. I've done this in response to multiple comments indicating that the warnings are hard to interpret. This change is meant to be applied on top of the patch for bug 83698 (submitted mainly to improve the readability of the offsets): https://gcc.gnu.org/ml/gcc-patches/2018-01/msg01488.html Martin
