GCC build failure seen on F42 and F43

Ask Fedora
1

I have a program that I have trimmed down that fails to build with GCC on F42 and F43. It used to build and does build with clang. The error generated makes no sense to me:

cc -O3 -Wall -Werror -Wextra -Wmissing-prototypes -Wstrict-prototypes -Wcast-align -Wcast-qual -Wformat=2 -Wundef -MD -MF obj/gccbug.o.d -c -o obj/gccbug.o gccbug.c

In function ‘setAll’,

inlined from ‘**do_work**’ at **gccbug.c:39:2**,

inlined from ‘**main**’ at **gccbug.c:48:2**:

gccbug.c:28:34: error: ‘__builtin_memset’ writing 632 bytes into a region of size 628 [-Werror=stringop-overflow=]

28 | *(ba->p + intSS) = ~0;

  |                 **\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~^\~\~\~**

In function ‘createBitArray’,

inlined from ‘**do_work**’ at **gccbug.c:38:7**,

inlined from ‘**main**’ at **gccbug.c:48:2**:

gccbug.c:19:17: note: destination object of size 628 allocated by ‘malloc’

19 | ba->p = malloc(ba->intsInArray * sizeof(BIT_WORD_TYPE));

  |                 **^\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~**

cc1: all warnings being treated as errors

I have seen the error both on X86_64 and riscv64. I would upload the source but I don’t see a way to do that here. Tell me how to do that and I will.

2

Sorry. I think I figured it out. There is no problem with GCC. Sorry for the noise.