[Bug c/108310] Some warnings that -Wtraditional-conversion causes to be emitted aren't actually controlled by it

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108310

--- Comment #3 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Eric Gallager from comment #0)
> So, I'm having trouble crafting a testcase that properly reproduces this
> issue, but...

...for reference, this is what I've got so far:

$ cat Wtraditional_conversion_darwin.c
#include <architecture/byte_order.h>
#include <sys/types.h>
#include <inttypes.h>

uint32_t foo(float x)
{
        return OSSwapHostToLittleInt32(x);
}

int32_t bar(double x)
{
        return OSSwapHostToBigInt32(x);
}
$

Unfortunately, the only warning that it produces so far *is* actually
controlled by -Wtraditional-conversion properly, so it's not an example of this
bug (yet):

$ /usr/local/bin/gcc -c -Wall -Wextra -pedantic -Wtraditional-conversion
Wtraditional_conversion_darwin.c
In file included from
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/libkern/OSByteOrder.h:33,
                 from
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/architecture/byte_order.h:38,
                 from Wtraditional_conversion_darwin.c:1:
Wtraditional_conversion_darwin.c: In function 'bar':
Wtraditional_conversion_darwin.c:12:37: warning: passing argument 1 of
'_OSSwapInt32' as integer rather than floating due to prototype
[-Wtraditional-conversion]
   12 |         return OSSwapHostToBigInt32(x);
      |                                     ^
$

ref:
https://github.com/cooljeanius/gcc_bugs/blob/master/Wtraditional_conversion_darwin.c