On 8/30/16, Marek Polacek <pola...@redhat.com> wrote:
> On Mon, Aug 29, 2016 at 09:32:04AM -0400, Eric Gallager wrote:
>> I tried v6 on my binutils-gdb fork, and it printed A LOT of
>> warnings...
>
> BTW, why is that so? Does binutils-gdb not use various FALLTHRU comments?
>
> Marek
>
There are a lot of comments mentioning fallthroughs, but they mostly
need to be rewritten to be recognized properly. There's just so many
different ways of writing them. For example, one I've seen a lot
writes it as "Drop through" instead of "Fall through" or something.
Other examples of comments mentioning fallthroughs:
/* else fall through */
/* else fallthrough to: */
/* FALL THRU into number case. */
/* ObjC NSString constant: fall through and parse like STRING. */
/* Fall through, pretend it is global. */
/* Fall through into normal member function. */
/* fall in for static symbols that do NOT start with '.' */
/* >>> !! else fall through !! <<< */
/* ... fall through for unsigned ints ... */
/* fall thru to manual case */
Also, at second glance, it's actually not quite as many warnings as I
thought it was at first, it mostly just looked that way since each
-Wimplicit-fallthrough warning takes up 12 lines due to the
double-fixits. FWIW, Aldy's -Walloca-larger-than patch actually was
noisier in the GDB portion at least. (The Binutils portion was already
clean on its alloca usage since it already used the -Wstack-usage
warning.)
Oh, and one other thing I discovered:
__attribute__((fallthrough)) triggers -Wdeclaration-after-statement:
In file included from ./defs.h:124:0,
from ./cli/cli-setshow.c:20:
./cli/cli-setshow.c: In function ‘do_setshow_command’:
./../include/ansidecl.h:505:33: warning: ISO C90 forbids mixed
declarations and code [-Wdeclaration-after-statement]
# define ATTRIBUTE_FALLTHROUGH __attribute__((fallthrough))
^
./cli/cli-setshow.c:359:4: note: in expansion of macro ‘ATTRIBUTE_FALLTHROUGH’
ATTRIBUTE_FALLTHROUGH;
^~~~~~~~~~~~~~~~~~~~~
Which doesn't really make sense to me.
