Mercurial > hg > octave-lyh > gnulib-hg
changeset 16508:72cfe53065d1
stdnoreturn: port to MSVC better
MSVC standard headers use __declspec(noreturn), so #define noreturn
to empty on that platform. Reported by Bruno Haible in
<http://lists.gnu.org/archive/html/bug-gnulib/2012-02/msg00152.html>.
* lib/stdnoreturn.in.h (noreturn): Define to empty on MSVC.
* doc/posix-headers/stdnoreturn.texi (stdnoreturn.h): Document this.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Wed, 29 Feb 2012 01:48:18 -0800 |
parents | a7ef52eff5fb |
children | d2a4b2dea076 |
files | ChangeLog doc/posix-headers/stdnoreturn.texi lib/stdnoreturn.in.h |
diffstat | 3 files changed, 30 insertions(+), 1 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2012-02-29 Paul Eggert <eggert@cs.ucla.edu> + + stdnoreturn: port to MSVC better + MSVC standard headers use __declspec(noreturn), so #define noreturn + to empty on that platform. Reported by Bruno Haible in + <http://lists.gnu.org/archive/html/bug-gnulib/2012-02/msg00152.html>. + * lib/stdnoreturn.in.h (noreturn): Define to empty on MSVC. + * doc/posix-headers/stdnoreturn.texi (stdnoreturn.h): Document this. + 2012-02-28 Bruno Haible <bruno@clisp.org> doc: Mention new glibc headers and functions.
--- a/doc/posix-headers/stdnoreturn.texi +++ b/doc/posix-headers/stdnoreturn.texi @@ -21,4 +21,12 @@ @item You cannot assume that @code{_Noreturn} is a reserved word; it might be a macro. +@item +On MSVC 9, @code{noreturn} expands to the empty token sequence, to avoid +problems with standard headers that use @code{__declspec (noreturn)} +directly. Although the resulting code operates correctly, the +compiler is not informed whether @code{noreturn} functions do not +return, so it may generate incorrect warnings at compile-time, or code +that is slightly less optimized. This problem does not occur with +@code{_Noreturn}. @end itemize
--- a/lib/stdnoreturn.in.h +++ b/lib/stdnoreturn.in.h @@ -28,7 +28,19 @@ /* The definition of _Noreturn is copied here. */ -#define noreturn _Noreturn +#if 1200 <= _MSC_VER +/* Standard include files on this platform contain declarations like + "__declspec (noreturn) void abort (void);". "#define noreturn + _Noreturn" would cause this declaration to be rewritten to the + invalid "__declspec (__declspec (noreturn)) void abort (void);". + Instead, define noreturn to empty, so that such declarations are + rewritten to "__declspec () void abort (void);", which is + equivalent to "void abort (void);"; this gives up on noreturn's + advice to the compiler but at least it is valid code. */ +# define noreturn /*empty*/ +#else +# define noreturn _Noreturn +#endif /* Did he ever return? No he never returned