Re: C23 thoughts and opinions

On Fri, 31 May 2024 19:03:10 +0100
bart <bc@freeuk.com> wrote:

 
OK, thanks. But I forget to ask what results you got from running the
program. Because if I try your code, using hello.c and hello.exe as
test binary/source data, I get this output:
 
_binary_test_bi_start                    00007ff6497620e0
140695771160800 _binary_test_bi_end
00007ff649762ae0 140695771163360 _binary_test_bi_size
    00007ff509750a00 140690402380288 _binary_bin_to_list_c_start
        00007ff649762ae0 140695771163360 _binary_bin_to_list_c_end
            00007ff649762b26 140695771163430
_binary_bin_to_list_c_size               00007ff509750046
140690402377798
 
The sizes should have been 2560 and 70 respectively; those values are
bit bigger than that.
 

That's strange.  I got expected results:
_binary_test_bi_start                    000000013FDD30C0 5366427840
_binary_test_bi_end                      000000013FDD67AC 5366441900
_binary_test_bi_size                     00000000000036EC 14060
_binary_bin_to_list_c_start              000000013FDD67AC 5366441900
_binary_bin_to_list_c_end                000000013FDD711F 5366444319
_binary_bin_to_list_c_size               0000000000000973 2419

However I see that you also have start and end addresses, which
sounds a much better way of determining the size. (In that case, what
are those *size symbols for?).
>

I'd guess, *_size is here for the benefit of less smart compilers that
can not figure out that *_end - *_start is a connst expression
and can not compile code like:

static ptrdiff_t bar = _binary_test_bi_end - _binary_test_bi_start;


But that is just a guess. For better answer you can ask authors of
objcopy.