error: use of undeclared identifier '__noreturn__'

error: use of undeclared identifier '__noreturn__'

[Jeffrey Walton]

Hi Everyone,

An FYI since I saw some chatter about Noreturn recently...

I'm building GnuTLS 3.6.12 release tarball on OS X 10.9. GnuTLS has a
copy of gnulib. The compile is failing:

gcc -DHAVE_CONFIG_H -I. -I..  -I./gl -I./gl -I./../lib/includes
-I./../lib/includes -I./../libdane/includes -I./../extra/includes
-I../src/libopts -I./libopts  -I/usr/local/include -DNDEBUG
-fno-common -Wall   -g2 -O2 -march=native -fPIC -pthread -MT tests.o
-MD -MP -MF $depbase.Tpo -c -o tests.o tests.c &&\
mv -f $depbase.Tpo $depbase.Po
In file included from psk.c:50:
In file included from ./gl/unistd.h:40:
/usr/include/unistd.h:424:18: error: use of undeclared identifier '__noreturn__'
void     _exit(int) __dead2;
                    ^
/usr/include/sys/cdefs.h:135:33: note: expanded from macro '__dead2'
#define __dead2         __attribute__((noreturn))
                                       ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/include/stdnoreturn.h:27:18:
note:
      expanded from macro 'noreturn'
#define noreturn _Noreturn
                 ^
../config.h:1821:37: note: expanded from macro '_Noreturn'
#  define _Noreturn __attribute__ ((__noreturn__))

I can provide SSH access to the box if someone is interested in
testing this. Email me with your authorized_keys.

Jeff