On my Fedora 20 box with mingw cross-compiler, the build failed with: ../../src/rpc/virnetclient.c: In function 'virNetClientSetTLSSession': ../../src/rpc/virnetclient.c:745:14: error: unused variable 'oldmask' [-Werror=unused-variable] sigset_t oldmask, blockedsigs; ^ I traced it to the fact that mingw64-winpthreads installs a header that does #define pthread_sigmask(...) 0, which means any argument only ever passeed to pthread_sigmask is reported as unused. This patch works around the compilation failure, with behavior no worse than what mingw already gives us regarding the function being a no-op. * configure.ac (pthread_sigmask): Probe for broken mingw macro. * src/util/virutil.h (pthread_sigmask): Rewrite to something that avoids unused variables. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- It helps if I save my editor buffer _before_ creating the commit and sending the email :) configure.ac | 18 +++++++++++++++++- src/util/virutil.h | 21 ++++++++++++++++----- 2 files changed, 33 insertions(+), 6 deletions(-) diff --git a/configure.ac b/configure.ac index d02b9d2..f5dccf1 100644 --- a/configure.ac +++ b/configure.ac @@ -1,6 +1,6 @@ dnl Process this file with autoconf to produce a configure script. -dnl Copyright (C) 2005-2013 Red Hat, Inc. +dnl Copyright (C) 2005-2014 Red Hat, Inc. dnl dnl This library is free software; you can redistribute it and/or dnl modify it under the terms of the GNU Lesser General Public @@ -276,6 +276,22 @@ dnl LIB_PTHREAD and LIBMULTITHREAD were set during gl_INIT by gnulib. old_LIBS=$LIBS LIBS="$LIBS $LIB_PTHREAD $LIBMULTITHREAD" AC_CHECK_FUNCS([pthread_mutexattr_init]) +dnl At least mingw64-winpthreads #defines pthread_sigmask to 0, +dnl which in turn causes compilation to complain about unused variables. +dnl Expose this broken implementation, so we can work around it. +AC_CACHE_CHECK([whether pthread_sigmask does anything], + [lv_cv_pthread_sigmask_works], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ + #include <sys/types.h> + #include <signal.h> + ]], [[ + int (*foo)(int, const sigset_t *, sigset_t *) = &pthread_sigmask; + return !foo; + ]])], [lv_cv_pthread_sigmask_works=yes], [lv_cv_pthread_sigmask_works=no])]) +if test "x$lv_cv_pthread_sigmask_works" != xyes; then + AC_DEFINE([FUNC_PTHREAD_SIGMASK_BROKEN], [1], + [Define to 1 if pthread_sigmask is not a real function]) +fi LIBS=$old_libs dnl Availability of various common headers (non-fatal if missing). diff --git a/src/util/virutil.h b/src/util/virutil.h index 2229c73..7b2af75 100644 --- a/src/util/virutil.h +++ b/src/util/virutil.h @@ -1,7 +1,7 @@ /* * virutil.h: common, generic utility functions * - * Copyright (C) 2010-2013 Red Hat, Inc. + * Copyright (C) 2010-2014 Red Hat, Inc. * Copyright (C) 2006, 2007 Binary Karma * Copyright (C) 2006 Shuveb Hussain * @@ -96,20 +96,31 @@ const char *virEnumToString(const char *const*types, const char *name ## TypeToString(int type); \ int name ## TypeFromString(const char*type); +/* No-op workarounds for functionality missing in mingw. */ # ifndef HAVE_GETUID -static inline int getuid (void) { return 0; } +static inline int getuid(void) { return 0; } # endif # ifndef HAVE_GETEUID -static inline int geteuid (void) { return 0; } +static inline int geteuid(void) { return 0; } # endif # ifndef HAVE_GETGID -static inline int getgid (void) { return 0; } +static inline int getgid(void) { return 0; } # endif # ifndef HAVE_GETEGID -static inline int getegid (void) { return 0; } +static inline int getegid(void) { return 0; } +# endif + +# ifdef FUNC_PTHREAD_SIGMASK_BROKEN +# undef pthread_sigmask +static inline int pthread_sigmask(int how ATTRIBUTE_UNUSED, + const void *set ATTRIBUTE_UNUSED, + void *old ATTRIBUTE_UNUSED) +{ + return 0; +} # endif char *virGetHostname(void); -- 1.8.4.2