gcc-14-1-0: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]

[Josef Wolf <jw@xxxxxxxxxxxxx>]

Hallo,

just upgraded my crossgcc-toolchain to gcc-1-14-0.

Given this code snippet:

  #define MG 32
  static unsigned char a[MG] = {0};

  void init_login (void)
  {
      int i;

      for (i=0; i<MG; i++) {
         a[i] = 1;
      }
  }

IMHO, this code should not access index 32 of the array, because
the for loop should terminate.

Thus, following warning is completely unexpected to me:

  m68k-unknown-elf-gcc -ansi -pedantic -Wall -Wcast-align -Wstrict-prototypes -Wmissing-prototypes -std=c99 -Wnull-dereference -g  -O3 -fno-toplevel-reorder  -mcpu32 -ffreestanding -c -o login.o login.c
  login.c: In function 'init_login':
  login.c:2909:22: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
   2909 |                 a[i] = 1;
        |                 ~~~~~^~~
  login.c:2899:22: note: at offset 32 into destination object 'a' of size 32
   2899 | static unsigned char a[MG] = {0};
        |                      ^

Opinions?

-- 
Josef Wolf
jw@xxxxxxxxxxxxx