Hi Paul, > (1) add support for the draft C1X _Noreturn keyword, > (2) add support for the draft C1X <stdnoreturn.h> include, and > (3) have the rest of gnulib use (1) and (2)
In patches [06] to [13], you use _Noreturn. In patches [14] to [18], you use noreturn. Which seems inconsistent. Is it better to use the C identifier '_Noreturn' (1) or 'noreturn' (2)? 1) One one hand, it appears that the intent of the ISO C committee is that '_Noreturn' is (like '_Bool') the keyword that only C wizards know about, whereas 'noreturn' (like 'bool') is the identifier that everyone uses, 2) BUT! The ISO C++ draft <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf> does not specify _Noreturn but it specifies a different syntax: [[noreturn]] void f (void); 3) On the other hand, 'noreturn' is already used as a keyword by Microsoft C compilers. Cf. <http://msdn.microsoft.com/en-us/library/k6ktzx3s(v=vs.80).aspx> Here's a grep of the MSVC header files: $ grep noreturn * eh.h:_CRTIMP __declspec(noreturn) void __cdecl terminate(void); eh.h:_CRTIMP __declspec(noreturn) void __cdecl unexpected(void); process.h:_CRTIMP __declspec(noreturn) void __cdecl abort(void); process.h:_CRTIMP __declspec(noreturn) void __cdecl exit(int); process.h:_CRTIMP __declspec(noreturn) void __cdecl _exit(int); setjmp.h:_CRTIMP __declspec(noreturn) void __cdecl longjmp(jmp_buf, int); stdlib.h:_CRTIMP __declspec(noreturn) void __cdecl abort(void); stdlib.h:_CRTIMP __declspec(noreturn) void __cdecl exit(int); stdlib.h:_CRTIMP __declspec(noreturn) void __cdecl _exit(int); and of the mingw header files: $ grep noreturn * assert.h: __attribute__ ((noreturn)) stdlib.h:#define _ATTRIB_NORETURN __attribute__ ((noreturn)) windef.h:#define DECLSPEC_NORETURN __declspec(noreturn) In summary, it looks to me that the ISO C and ISO C++ committees need to do some more work to align the syntaxes. extern noreturn void _Exit (void); vs. extern [[noreturn]] void _Exit (void); And on the gnulib side, either we should wait until the ISO C and ISO C++ drafts have converged, or we should use _Noreturn everywhere and not use 'noreturn' (1. because of C++, 2. because of Microsoft's compiler). Bruno -- In memoriam Zahra Kazemi <http://en.wikipedia.org/wiki/Zahra_Kazemi>
