From 5865e064abfbbe11ebfc09881be009c0f69b4dc2 Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Thu, 15 Jul 2021 12:23:47 +1200 Subject: [PATCH] Portability fixes for sigwait. Build farm animals running ancient HPUX and Solaris have a non-standard sigwait() from draft versions of POSIX, so they didn't like commit 7c09d279. To avoid the problem in general, only try to use sigwait() if it's declared by and matches the expected declaration. To select the modern declaration on Solaris (even in non-threaded programs), move -D_POSIX_PTHREAD_SEMANTICS into the right place to affect all translation units. Also fix the error checking. Modern sigwait() doesn't set errno. Thanks to Tom Lane for help with this. Discussion: https://postgr.es/m/3187588.1626136248%40sss.pgh.pa.us --- config/thread_test.c | 4 -- configure | 75 +++++++++++++++++++++++++++++++++++--- configure.ac | 38 +++++++++++++++++-- src/bin/psql/command.c | 13 ++++--- src/bin/psql/startup.c | 4 +- src/include/pg_config.h.in | 7 ++++ src/tools/msvc/Solution.pm | 2 + 7 files changed, 122 insertions(+), 21 deletions(-) diff --git a/config/thread_test.c b/config/thread_test.c index 784f4fe8ce..e2a9e62f49 100644 --- a/config/thread_test.c +++ b/config/thread_test.c @@ -43,10 +43,6 @@ #include #endif -/* Test for POSIX.1c 2-arg sigwait() and fail on single-arg version */ -#include -int sigwait(const sigset_t *set, int *sig); - #define TEMP_FILENAME_1 "thread_test.1" #define TEMP_FILENAME_2 "thread_test.2" diff --git a/configure b/configure index 1ea28a0d67..c85eb1bf55 100755 --- a/configure +++ b/configure @@ -7194,6 +7194,12 @@ $as_echo "#define PROFILE_PID_DIR 1" >>confdefs.h fi fi +# On Solaris, we need this #define to get POSIX-conforming versions +# of many interfaces (sigwait, getpwuid_r, ...). +if test "$PORTNAME" = "solaris"; then + CPPFLAGS="$CPPFLAGS -D_POSIX_PTHREAD_SEMANTICS" +fi + # We already have this in Makefile.win32, but configure needs it too if test "$PORTNAME" = "win32"; then CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32" @@ -11296,9 +11302,8 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu # set thread flags # Some platforms use these, so just define them. They can't hurt if they -# are not supported. For example, on Solaris -D_POSIX_PTHREAD_SEMANTICS -# enables 5-arg getpwuid_r, among other things. -PTHREAD_CFLAGS="$PTHREAD_CFLAGS -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS" +# are not supported. +PTHREAD_CFLAGS="$PTHREAD_CFLAGS -D_REENTRANT -D_THREAD_SAFE" # Check for *_r functions _CFLAGS="$CFLAGS" @@ -15861,9 +15866,11 @@ $as_echo "#define HAVE_FSEEKO 1" >>confdefs.h fi -# posix_fadvise() is a no-op on Solaris, so don't incur function overhead -# by calling it, 2009-04-02 -# http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/posix_fadvise.c +# Make sure there's a declaration for sigwait(), then make sure +# that it conforms to the POSIX standard (there seem to still be +# some platforms out there with pre-POSIX sigwait()). On Solaris, +# _POSIX_PTHREAD_SEMANTICS affects the result, but we already +# added that to CPPFLAGS. # The Clang compiler raises a warning for an undeclared identifier that matches # a compiler builtin function. All extant Clang versions are affected, as of # Clang 3.6.0. Test a builtin known to every version. This problem affects the @@ -15952,6 +15959,62 @@ case $ac_cv_c_decl_report in *) ac_c_decl_warn_flag= ;; esac +ac_fn_c_check_decl "$LINENO" "sigwait" "ac_cv_have_decl_sigwait" "#include +" +if test "x$ac_cv_have_decl_sigwait" = xyes; then : + ac_have_decl=1 +else + ac_have_decl=0 +fi + +cat >>confdefs.h <<_ACEOF +#define HAVE_DECL_SIGWAIT $ac_have_decl +_ACEOF + +if test "x$ac_cv_have_decl_sigwait" = xyes; then + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for POSIX-conforming sigwait declaration" >&5 +$as_echo_n "checking for POSIX-conforming sigwait declaration... " >&6; } +if ${pgac_cv_have_posix_decl_sigwait+:} false; then : + $as_echo_n "(cached) " >&6 +else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + #include + int sigwait(const sigset_t *set, int *sig); + +int +main () +{ + + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + pgac_cv_have_posix_decl_sigwait=yes +else + pgac_cv_have_posix_decl_sigwait=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_have_posix_decl_sigwait" >&5 +$as_echo "$pgac_cv_have_posix_decl_sigwait" >&6; } +fi +if test "x$pgac_cv_have_posix_decl_sigwait" = xyes; then + +$as_echo "#define HAVE_POSIX_DECL_SIGWAIT 1" >>confdefs.h + +else + # On non-Windows, libpq requires POSIX sigwait() for thread safety. + if test "$enable_thread_safety" = yes -a "$PORTNAME" != "win32"; then + as_fn_error $? "POSIX-conforming sigwait is required to enable thread safety." "$LINENO" 5 + fi +fi + +# posix_fadvise() is a no-op on Solaris, so don't incur function overhead +# by calling it, 2009-04-02 +# http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/posix_fadvise.c if test "$PORTNAME" != "solaris"; then : for ac_func in posix_fadvise diff --git a/configure.ac b/configure.ac index 57336e1fb6..099c4a5a45 100644 --- a/configure.ac +++ b/configure.ac @@ -610,6 +610,12 @@ if test "$enable_profiling" = yes && test "$ac_cv_prog_cc_g" = yes; then fi fi +# On Solaris, we need this #define to get POSIX-conforming versions +# of many interfaces (sigwait, getpwuid_r, ...). +if test "$PORTNAME" = "solaris"; then + CPPFLAGS="$CPPFLAGS -D_POSIX_PTHREAD_SEMANTICS" +fi + # We already have this in Makefile.win32, but configure needs it too if test "$PORTNAME" = "win32"; then CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32" @@ -1122,9 +1128,8 @@ AS_IF([test "$enable_thread_safety" = yes -a "$PORTNAME" != "win32"], AX_PTHREAD # set thread flags # Some platforms use these, so just define them. They can't hurt if they -# are not supported. For example, on Solaris -D_POSIX_PTHREAD_SEMANTICS -# enables 5-arg getpwuid_r, among other things. -PTHREAD_CFLAGS="$PTHREAD_CFLAGS -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS" +# are not supported. +PTHREAD_CFLAGS="$PTHREAD_CFLAGS -D_REENTRANT -D_THREAD_SAFE" # Check for *_r functions _CFLAGS="$CFLAGS" @@ -1741,6 +1746,33 @@ PGAC_CHECK_BUILTIN_FUNC([__builtin_popcount], [unsigned int x]) # in case it finds that _LARGEFILE_SOURCE has to be #define'd for that. AC_FUNC_FSEEKO +# Make sure there's a declaration for sigwait(), then make sure +# that it conforms to the POSIX standard (there seem to still be +# some platforms out there with pre-POSIX sigwait()). On Solaris, +# _POSIX_PTHREAD_SEMANTICS affects the result, but we already +# added that to CPPFLAGS. +AC_CHECK_DECLS(sigwait, [], [], [#include ]) +if test "x$ac_cv_have_decl_sigwait" = xyes; then + AC_CACHE_CHECK([for POSIX-conforming sigwait declaration], + [pgac_cv_have_posix_decl_sigwait], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([ + #include + int sigwait(const sigset_t *set, int *sig); + ], + [])], + [pgac_cv_have_posix_decl_sigwait=yes], + [pgac_cv_have_posix_decl_sigwait=no])]) +fi +if test "x$pgac_cv_have_posix_decl_sigwait" = xyes; then + AC_DEFINE(HAVE_POSIX_DECL_SIGWAIT, 1, + [Define to 1 if you have a POSIX-conforming sigwait declaration.]) +else + # On non-Windows, libpq requires POSIX sigwait() for thread safety. + if test "$enable_thread_safety" = yes -a "$PORTNAME" != "win32"; then + AC_MSG_ERROR([POSIX-conforming sigwait is required to enable thread safety.]) + fi +fi + # posix_fadvise() is a no-op on Solaris, so don't incur function overhead # by calling it, 2009-04-02 # http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/posix_fadvise.c diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index d704c4220c..49d4c0e3ce 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -4899,7 +4899,7 @@ do_watch(PQExpBuffer query_buf, double sleep) FILE *pagerpipe = NULL; int title_len; int res = 0; -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT sigset_t sigalrm_sigchld_sigint; sigset_t sigalrm_sigchld; sigset_t sigint; @@ -4913,7 +4913,7 @@ do_watch(PQExpBuffer query_buf, double sleep) return false; } -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT sigemptyset(&sigalrm_sigchld_sigint); sigaddset(&sigalrm_sigchld_sigint, SIGCHLD); sigaddset(&sigalrm_sigchld_sigint, SIGALRM); @@ -4952,7 +4952,7 @@ do_watch(PQExpBuffer query_buf, double sleep) * PAGER environment variables, because traditional pagers probably won't * be very useful for showing a stream of results. */ -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT pagerprog = getenv("PSQL_WATCH_PAGER"); #endif if (pagerprog && myopt.topt.pager) @@ -5023,7 +5023,7 @@ do_watch(PQExpBuffer query_buf, double sleep) if (pagerpipe && ferror(pagerpipe)) break; -#ifdef WIN32 +#ifndef HAVE_POSIX_DECL_SIGWAIT /* * Set up cancellation of 'watch' via SIGINT. We redo this each time @@ -5059,7 +5059,8 @@ do_watch(PQExpBuffer query_buf, double sleep) { int signal_received; - if (sigwait(&sigalrm_sigchld_sigint, &signal_received) < 0) + errno = sigwait(&sigalrm_sigchld_sigint, &signal_received); + if (errno != 0) { /* Some other signal arrived? */ if (errno == EINTR) @@ -5091,7 +5092,7 @@ do_watch(PQExpBuffer query_buf, double sleep) restore_sigpipe_trap(); } -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT /* Disable the interval timer. */ memset(&interval, 0, sizeof(interval)); setitimer(ITIMER_REAL, &interval, NULL); diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c index 5f36f0d1c6..2931530f33 100644 --- a/src/bin/psql/startup.c +++ b/src/bin/psql/startup.c @@ -110,7 +110,7 @@ log_locus_callback(const char **filename, uint64 *lineno) } } -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT static void empty_signal_handler(SIGNAL_ARGS) { @@ -309,7 +309,7 @@ main(int argc, char *argv[]) psql_setup_cancel_handler(); -#ifndef WIN32 +#ifdef HAVE_POSIX_DECL_SIGWAIT /* * do_watch() needs signal handlers installed (otherwise sigwait() will diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index d69d461ff2..15ffdd895a 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -158,6 +158,10 @@ don't. */ #undef HAVE_DECL_RTLD_NOW +/* Define to 1 if you have the declaration of `sigwait', and to 0 if you + don't. */ +#undef HAVE_DECL_SIGWAIT + /* Define to 1 if you have the declaration of `strlcat', and to 0 if you don't. */ #undef HAVE_DECL_STRLCAT @@ -414,6 +418,9 @@ /* Define to 1 if you have the header file. */ #undef HAVE_POLL_H +/* Define to 1 if you have a POSIX-conforming sigwait declaration. */ +#undef HAVE_POSIX_DECL_SIGWAIT + /* Define to 1 if you have the `posix_fadvise' function. */ #undef HAVE_POSIX_FADVISE diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index 294b968dcd..c967743467 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -249,6 +249,7 @@ sub GenerateFiles HAVE_DECL_PWRITEV => 0, HAVE_DECL_RTLD_GLOBAL => 0, HAVE_DECL_RTLD_NOW => 0, + HAVE_DECL_SIGWAIT => 0, HAVE_DECL_STRLCAT => undef, HAVE_DECL_STRLCPY => undef, HAVE_DECL_STRNLEN => 1, @@ -332,6 +333,7 @@ sub GenerateFiles HAVE_PAM_PAM_APPL_H => undef, HAVE_POLL => undef, HAVE_POLL_H => undef, + HAVE_POSIX_DECL_SIGWAIT => undef, HAVE_POSIX_FADVISE => undef, HAVE_POSIX_FALLOCATE => undef, HAVE_PPC_LWARX_MUTEX_HINT => undef,