Silly: why I don't see effect of -fstack-size-section?

Hi All,
I have the following piece of code:

#include <stdio.h>

int abc(void) {
char a[4];
a[0] = 0;
printf("%c", a[0]);
return 0;
}

I do:
$ /usr/local/Cellar/llvm/10.0.0_3/bin/clang stack.c -c -fstack-size-section
$ ls -la stack.o
-rw-r–r-- 1 renat staff 760 Jul 17 15:31 stack.o

$ /usr/local/Cellar/llvm/10.0.0_3/bin/clang stack.c -c -fno-stack-size-section
$ ls -la stack.o
-rw-r–r-- 1 renat staff 760 Jul 17 15:32 stack.o

also if I try to find the section, I don’t see it (with -fstack-size-section)
$ objdump -s stack.o

stack.o: file format Mach-O 64-bit x86-64

Contents of section __text:
0000 554889e5 4883ec10 c645fc00 0fbe75fc UH…H…E…u.
0010 488d3d14 000000b0 00e80000 000031c9 H.=…1.
0020 8945f889 c84883c4 105dc3 .E…H…].
Contents of section __cstring:
002b 256300 %c.
Contents of section __compact_unwind:
0030 00000000 00000000 2b000000 00000001 …+…
0040 00000000 00000000 00000000 00000000 …
Contents of section __eh_frame:
0050 14000000 00000000 017a5200 01781001 …zR…x…
0060 100c0708 90010000 24000000 1c000000 …$…
0070 90ffffff ffffffff 2b000000 00000000 …+…
0080 00410e10 8602430d 06000000 00000000 .A…C…

What am I missing?

Thank you!

-fstack-size-sections is only available for ELF (not for COFF/Mach-O/wasm/etc).

There is interesting design issues related to dead stripping/COMDAT/cost
of metadata sections. This is currently fixed in ELF (due to the use of SHF_LINK_ORDER,
GNU as and ld from GNU binutils 2.35 onwards work). Similar
considerations need to be taken if someone wants to support other binary formats.