[llvm-commits] [llvm] r172156 - /llvm/trunk/include/llvm/Support/Compiler.h

[Dmitri Gribenko]

On Fri, Jan 11, 2013 at 4:50 PM, Joerg Sonnenberger
<joerg at britannica.bec.de> wrote:
> On Fri, Jan 11, 2013 at 02:32:41PM +0200, Dmitri Gribenko wrote:
>> On Fri, Jan 11, 2013 at 4:59 AM, Joerg Sonnenberger
>> <joerg at britannica.bec.de> wrote:
>> > On Fri, Jan 11, 2013 at 04:37:34AM +0200, Dmitri Gribenko wrote:
>> >> On Fri, Jan 11, 2013 at 4:33 AM, Joerg Sonnenberger
>> >> <joerg at britannica.bec.de> wrote:
>> >> > On Fri, Jan 11, 2013 at 01:13:51AM -0000, Dmitri Gribenko wrote:
>> >> >> Author: gribozavr
>> >> >> Date: Thu Jan 10 19:13:51 2013
>> >> >> New Revision: 172156
>> >> >>
>> >> >> URL: http://llvm.org/viewvc/llvm-project?rev=172156&view=rev
>> >> >> Log:
>> >> >> Add a new portability macro LLVM_FUNCTION_NAME, that expands to __func__, if
>> >> >> supported.
>> >> >>
>> >> >> Modified:
>> >> >>     llvm/trunk/include/llvm/Support/Compiler.h
>> >> >
>> >> > Why don't you add
>> >> >
>> >> > #if defined(_MSC_VER)
>> >> > #define __func__ __FUNCTION__
>> >> > #endif
>> >> >
>> >> > to config.h?
>> >>
>> >> Because __func__ should be defined as:
>> >>
>> >> static const char __func__[] = "function-name";
>> >>
>> >> Replacements available in other compilers might behave in a different
>> >> way, thus we need a different name to avoid confusion.
>> >
>> > Eh, no. The main point is that you can't use __func__ in ways that
>> > expect string merging, so "foo" __func__ "bar" doesn't work unlike e.g.
>> > GCC's __FUNCTION__. __func__ can always be replaced by "" with minimal
>> > lose of functionality.
>>
>> I don't see how this contradicts what I said: available replacements
>> might have different behavior.
>>
>> Anyway, #define __func__ <anything> is UB since name __func__ is reserved.
>
> Now you are silly. Yes, __func__ is a reserved macro name in C99. Point
> is that Microsoft does not implement C99, so it is not reserved in their
> dialect either.

__func__ is still reserved because it contains two underscores -- all
identifiers that match the regex /.*__.*/ are reserved in C++
([global.names] p1).

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/