> First, a renewed 'raise' module. Then, a wrapper around signal() in the 'sigprocmask' module. Most programs use sigaction() by now, which is provided by gnulib on MSVC, therefore there is no big urgency in adding a module for the signal() function.
2011-09-23 Bruno Haible <[email protected]> sigprocmask: Avoid crashes through signal() on MSVC 9. * lib/sigprocmask.c: Include msvc-inval.h. (signal_nothrow): New function. (signal): Redefine it. * m4/signalblocking.m4 (gl_PREREQ_SIGPROCMASK): Require AC_C_INLINE. * modules/sigprocmask (Depends-on): Add msvc-inval. * doc/posix-functions/signal.texi: Mention the problem on MSVC. --- doc/posix-functions/signal.texi.orig Sat Sep 24 01:04:40 2011 +++ doc/posix-functions/signal.texi Sat Sep 24 00:55:29 2011 @@ -13,6 +13,9 @@ Portability problems not fixed by Gnulib: @itemize @item +This function crashes when invoked with invalid arguments on some platforms: +MSVC 9. +@item On System V platforms, when the signal is triggered, the kernel uninstalls the handler (i.e.@: resets the signal's action to SIG_DFL) before invoking the handler. This opens the door to race conditions: undesired things happen --- lib/sigprocmask.c.orig Sat Sep 24 01:04:40 2011 +++ lib/sigprocmask.c Sat Sep 24 01:04:22 2011 @@ -24,6 +24,8 @@ #include <stdint.h> #include <stdlib.h> +#include "msvc-inval.h" + /* We assume that a platform without POSIX signal blocking functions also does not have the POSIX sigaction() function, only the signal() function. We also assume signal() has SysV semantics, @@ -58,6 +60,28 @@ typedef void (*handler_t) (int); +#if HAVE_MSVC_INVALID_PARAMETER_HANDLER +static inline handler_t +signal_nothrow (int sig, handler_t handler) +{ + handler_t result; + + TRY_MSVC_INVAL + { + result = signal (sig, handler); + } + CATCH_MSVC_INVAL + { + result = SIG_ERR; + errno = EINVAL; + } + DONE_MSVC_INVAL; + + return result; +} +# define signal signal_nothrow +#endif + /* Handling of gnulib defined signals. */ #if GNULIB_defined_SIGPIPE @@ -80,6 +104,7 @@ return signal (sig, handler); } } +# undef signal # define signal ext_signal #endif --- m4/signalblocking.m4.orig Sat Sep 24 01:04:40 2011 +++ m4/signalblocking.m4 Fri Sep 23 23:39:20 2011 @@ -1,4 +1,4 @@ -# signalblocking.m4 serial 12 +# signalblocking.m4 serial 13 dnl Copyright (C) 2001-2002, 2006-2011 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -22,4 +22,6 @@ ]) # Prerequisites of lib/sigprocmask.c. -AC_DEFUN([gl_PREREQ_SIGPROCMASK], [:]) +AC_DEFUN([gl_PREREQ_SIGPROCMASK], [ + AC_REQUIRE([AC_C_INLINE]) +]) --- modules/sigprocmask.orig Sat Sep 24 01:04:40 2011 +++ modules/sigprocmask Fri Sep 23 23:38:44 2011 @@ -9,6 +9,7 @@ signal stdint [test $HAVE_POSIX_SIGNALBLOCKING = 0] raise [test $HAVE_POSIX_SIGNALBLOCKING = 0] +msvc-inval [test $HAVE_POSIX_SIGNALBLOCKING = 0] configure.ac: gl_SIGNALBLOCKING -- In memoriam Ghazala Khan <http://en.wikipedia.org/wiki/Ghazala_Khan>
