From: Tom Lane Date: Sun, 18 May 2025 16:45:55 +0000 (-0400) Subject: Make our usage of memset_s() conform strictly to the C11 standard. X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=a1e0e7076585323270681dc9a4f9e1272f24db68;p=postgresql.git Make our usage of memset_s() conform strictly to the C11 standard. Per the letter of the C11 standard, one must #define __STDC_WANT_LIB_EXT1__ as 1 before including in order to have access to memset_s(). It appears that many platforms are lenient about this, because we weren't doing it and yet the code appeared to work anyway. But we now find that with -std=c11, macOS is strict and doesn't declare memset_s, leading to compile failures since we try to use it anyway. (Given the lack of prior reports, perhaps this is new behavior in the latest SDK? No matter, we're clearly in the wrong.) In addition to the immediate problem, which could be fixed merely by adding the needed #define to explicit_bzero.c, it seems possible that our configure-time probe for memset_s() could fail in case a platform implements the function in some odd way due to this spec requirement. This concern can be fixed in largely the same way that we dealt with strchrnul() in 6da2ba1d8: switch to using a declaration-based configure probe instead of a does-it-link probe. Back-patch to v13 where we started using memset_s(). Reported-by: Lakshmi Narayana Velayudam Author: Tom Lane Discussion: https://postgr.es/m/CAA4pTnLcKGG78xeOjiBr5yS7ZeE-Rh=FaFQQGOO=nPzA1L8yEA@mail.gmail.com Backpatch-through: 13 --- diff --git a/configure b/configure index 7b8880a610d..2eba98c2888 100755 --- a/configure +++ b/configure @@ -16037,7 +16037,7 @@ fi LIBS_including_readline="$LIBS" LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'` -for ac_func in backtrace_symbols clock_gettime copyfile fdatasync getifaddrs getpeerucred getrlimit kqueue mbstowcs_l memset_s poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink readv setproctitle setproctitle_fast setsid shm_open strsignal symlink syncfs sync_file_range uselocale wcstombs_l writev +for ac_func in backtrace_symbols clock_gettime copyfile fdatasync getifaddrs getpeerucred getrlimit kqueue mbstowcs_l poll posix_fallocate ppoll pstat pthread_is_threaded_np readlink readv setproctitle setproctitle_fast setsid shm_open strsignal symlink syncfs sync_file_range uselocale wcstombs_l writev do : as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh` ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var" @@ -16613,6 +16613,19 @@ cat >>confdefs.h <<_ACEOF #define HAVE_DECL_STRCHRNUL $ac_have_decl _ACEOF +ac_fn_c_check_decl "$LINENO" "memset_s" "ac_cv_have_decl_memset_s" "#define __STDC_WANT_LIB_EXT1__ 1 +#include +" +if test "x$ac_cv_have_decl_memset_s" = xyes; then : + ac_have_decl=1 +else + ac_have_decl=0 +fi + +cat >>confdefs.h <<_ACEOF +#define HAVE_DECL_MEMSET_S $ac_have_decl +_ACEOF + # This is probably only present on macOS, but may as well check always ac_fn_c_check_decl "$LINENO" "F_FULLFSYNC" "ac_cv_have_decl_F_FULLFSYNC" "#include diff --git a/configure.ac b/configure.ac index 6dcfb4b5c87..a5d385e39aa 100644 --- a/configure.ac +++ b/configure.ac @@ -1795,7 +1795,6 @@ AC_CHECK_FUNCS(m4_normalize([ getrlimit kqueue mbstowcs_l - memset_s poll posix_fallocate ppoll @@ -1849,6 +1848,8 @@ AC_CHECK_DECLS([strlcat, strlcpy, strnlen]) AC_CHECK_DECLS([preadv], [], [AC_LIBOBJ(preadv)], [#include ]) AC_CHECK_DECLS([pwritev], [], [AC_LIBOBJ(pwritev)], [#include ]) AC_CHECK_DECLS([strchrnul], [], [], [#include ]) +AC_CHECK_DECLS([memset_s], [], [], [#define __STDC_WANT_LIB_EXT1__ 1 +#include ]) # This is probably only present on macOS, but may as well check always AC_CHECK_DECLS(F_FULLFSYNC, [], [], [#include ]) diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 605c830a1b2..906c7893553 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -135,6 +135,10 @@ to 0 if you don't. */ #undef HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN +/* Define to 1 if you have the declaration of `memset_s', and to 0 if you + don't. */ +#undef HAVE_DECL_MEMSET_S + /* Define to 1 if you have the declaration of `posix_fadvise', and to 0 if you don't. */ #undef HAVE_DECL_POSIX_FADVISE @@ -385,9 +389,6 @@ /* Define to 1 if you have the header file. */ #undef HAVE_MEMORY_H -/* Define to 1 if you have the `memset_s' function. */ -#undef HAVE_MEMSET_S - /* Define to 1 if the system has the type `MINIDUMP_TYPE'. */ #undef HAVE_MINIDUMP_TYPE diff --git a/src/port/explicit_bzero.c b/src/port/explicit_bzero.c index e39e20b8a56..3fece47c8cf 100644 --- a/src/port/explicit_bzero.c +++ b/src/port/explicit_bzero.c @@ -12,9 +12,11 @@ *------------------------------------------------------------------------- */ +#define __STDC_WANT_LIB_EXT1__ 1 /* needed to access memset_s() */ + #include "c.h" -#if defined(HAVE_MEMSET_S) +#if HAVE_DECL_MEMSET_S void explicit_bzero(void *buf, size_t len) diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm index 040e9d98b1f..4ec8769ecfc 100644 --- a/src/tools/msvc/Solution.pm +++ b/src/tools/msvc/Solution.pm @@ -243,6 +243,7 @@ sub GenerateFiles HAVE_DECL_LLVMGETHOSTCPUNAME => 0, HAVE_DECL_LLVMGETHOSTCPUFEATURES => 0, HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN => 0, + HAVE_DECL_MEMSET_S => 0, HAVE_DECL_POSIX_FADVISE => 0, HAVE_DECL_PREADV => 0, HAVE_DECL_PWRITEV => 0, @@ -322,7 +323,6 @@ sub GenerateFiles HAVE_MBARRIER_H => undef, HAVE_MBSTOWCS_L => 1, HAVE_MEMORY_H => 1, - HAVE_MEMSET_S => undef, HAVE_MINIDUMP_TYPE => 1, HAVE_MKDTEMP => undef, HAVE_NETINET_TCP_H => undef,