Date: Thu, 7 Dec 1995 05:58:15 +1100 From: Bruce Evans <bde@zeta.org.au> To: bde@zeta.org.au, phk@critter.tfs.com Cc: current@freebsd.org, imb@scgt.oz.au, julian@ref.tfs.com, terry@lambert.org Subject: Re: changes in -current..TEST please Message-ID: <199512061858.FAA31752@godzilla.zeta.org.au>
next in thread | raw e-mail | index | archive | help
>> >If you used up to date source, you would know that the above macro now
>> >looks like this:
>>
>> > #define MAKE_SET(set, sym, type) \
>> > static void *const __set_##set##_sym_##sym = \
>> > (&__set_##set##_sym_##sym, &sym, 0); \
>> > asm(".stabs \"_" #set "\", " #type ", 0, 0, _" #sym)
>>
>> >and that it (according to the gcc manual) ensures that the compiler will
>> >not remove your static and "secretly" referenced Symbols.
>>
>> The macro only tells the compiler about `sym'. `type' is only referenced
>> in the stab.
>type isn't an endangered species I think...
Oops.
The manual only seems to say that the above stops the warning. gcc-2.7
has a better method:
static void dummy_cleanup(void) __attribute__((__unused__));
This stops the warning but doesn't stop dummy_cleanup() going away with
-O3 any better than MAKE_SET() (it goes away because it becomes static
inline. static inlines _should_ go away).
Why not initialize a pointer to the function? Then the function address
_is_ used provided the pointer doesn't go away. Why does the comma
expression end with an 0 anyway? The following seems to work right
(except it wastes a pointer):
static void (*const foo)(void) = dummy_cleanup;
Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199512061858.FAA31752>