On Thu, May 31, 2012 at 1:02 PM, Howard Hinnant <[email protected]> wrote: > On May 31, 2012, at 3:58 PM, Chandler Carruth wrote: > >> On Thu, May 31, 2012 at 12:31 PM, Howard Hinnant <[email protected]> wrote: >> Author: hhinnant >> Date: Thu May 31 14:31:14 2012 >> New Revision: 157764 >> >> URL: http://llvm.org/viewvc/llvm-project?rev=157764&view=rev >> Log: >> Protect use of alignas against older versions of clang >> >> Modified: >> libcxx/trunk/include/__config >> libcxx/trunk/src/iostream.cpp >> >> Modified: libcxx/trunk/include/__config >> URL: >> http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__config?rev=157764&r1=157763&r2=157764&view=diff >> ============================================================================== >> --- libcxx/trunk/include/__config (original) >> +++ libcxx/trunk/include/__config Thu May 31 14:31:14 2012 >> @@ -145,8 +145,10 @@ >> #if defined(__clang__) >> >> #if __has_feature(cxx_alignas) >> +# define _ALIGNAS_TYPE(x) alignas(x) >> # define _ALIGNAS(x) alignas(x) >> #else >> +# define _ALIGNAS_TYPE(x) __attribute__((__aligned__)) >> >> Should this be __aligned__(x) as it is here: >> >> # define _ALIGNAS(x) __attribute__((__aligned__(x))) >> >> Or are you intentionally shooting for the 'maximally aligned' thing? If the >> latter, maybe comment that this is intentional and not a typo? > > It's intentional. My first try was using _ALIGNAS, and the compiler really > didn't like it: > > ../src/iostream.cpp:16:21: error: expected ')' > _ALIGNAS (__stdinbuf<char> ) static char __cin [sizeof(__stdinbuf <char>)]; > ^ > ../include/__config:149:50: note: expanded from macro '_ALIGNAS' > # define _ALIGNAS(x) __attribute__((__aligned__(x))) > ^ > > And so I punted by introducing _ALIGNAS_TYPE. > > I can add a comment, but I'd really like to hold trunk stable for just a > couple more hours.
The correct definition for _ALIGNAS_TYPE is something like the following: #define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))) -Eli _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
