On Mon, Dec 12, 2022 at 4:07 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Thomas Munro <thomas.mu...@gmail.com> writes: > > As visible on seawasp and locally (16/main branch nightly packages), > > they decided to start warning about these casts with a new strict > > variant of the warning. Their discussion: > > > https://reviews.llvm.org/D134831 > > > There are also a few other cases unrelated to this thread's original > > problem, for example casts involving pg_funcptr_t, HashCompareFunc. I > > guess our options would be to turn that warning off, or reconsider and > > try shoving the cast of "generic" arguments pointers down into the > > functions? > > I'm for "turn the warning off". Per previous discussion, adhering > strictly to that rule would make our code worse (less legible AND > less safe), not better.
Alright, this seems to do the trick here.
From b01690ca859b5f27ece386577b7b9d9d7572b8d2 Mon Sep 17 00:00:00 2001 From: Thomas Munro <thomas.mu...@gmail.com> Date: Mon, 12 Dec 2022 16:28:24 +1300 Subject: [PATCH] Disable clang 16's -Wcast-function-type-strict. Clang 16 is still in development, but seawasp reveals that it has started warning about many of our casts of function pointers. Disable the new warning for now, since otherwise buildfarm animal seawasp fails. May be back-patched with other Clang/LLVM 16 changes around release time. Discussion: https://postgr.es/m/CA%2BhUKGJvX%2BL3aMN84ksT-cGy08VHErRNip3nV-WmTx7f6Pqhyw%40mail.gmail.com --- configure | 44 ++++++++++++++++++++++++++++++++++++++++++++ configure.ac | 6 ++++++ meson.build | 3 +++ 3 files changed, 53 insertions(+) diff --git a/configure b/configure index 62f382c1d1..5025448a05 100755 --- a/configure +++ b/configure @@ -6611,6 +6611,50 @@ fi if test -n "$NOT_THE_CFLAGS"; then CFLAGS="$CFLAGS -Wno-stringop-truncation" fi + # Suppress clang 16's strict warnings about function casts + NOT_THE_CFLAGS="" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wcast-function-type-strict, for NOT_THE_CFLAGS" >&5 +$as_echo_n "checking whether ${CC} supports -Wcast-function-type-strict, for NOT_THE_CFLAGS... " >&6; } +if ${pgac_cv_prog_CC_cflags__Wcast_function_type_strict+:} false; then : + $as_echo_n "(cached) " >&6 +else + pgac_save_CFLAGS=$CFLAGS +pgac_save_CC=$CC +CC=${CC} +CFLAGS="${NOT_THE_CFLAGS} -Wcast-function-type-strict" +ac_save_c_werror_flag=$ac_c_werror_flag +ac_c_werror_flag=yes +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + +int +main () +{ + + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + pgac_cv_prog_CC_cflags__Wcast_function_type_strict=yes +else + pgac_cv_prog_CC_cflags__Wcast_function_type_strict=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +ac_c_werror_flag=$ac_save_c_werror_flag +CFLAGS="$pgac_save_CFLAGS" +CC="$pgac_save_CC" +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__Wcast_function_type_strict" >&5 +$as_echo "$pgac_cv_prog_CC_cflags__Wcast_function_type_strict" >&6; } +if test x"$pgac_cv_prog_CC_cflags__Wcast_function_type_strict" = x"yes"; then + NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -Wcast-function-type-strict" +fi + + + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-cast-function-type-strict" + fi elif test "$ICC" = yes; then # Intel's compiler has a bug/misoptimization in checking for # division by NAN (NaN == 0), -mp1 fixes it, so add it to the CFLAGS. diff --git a/configure.ac b/configure.ac index cfb10f59ce..4cd328fc83 100644 --- a/configure.ac +++ b/configure.ac @@ -573,6 +573,12 @@ if test "$GCC" = yes -a "$ICC" = no; then if test -n "$NOT_THE_CFLAGS"; then CFLAGS="$CFLAGS -Wno-stringop-truncation" fi + # Suppress clang 16's strict warnings about function casts + NOT_THE_CFLAGS="" + PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wcast-function-type-strict]) + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-cast-function-type-strict" + fi elif test "$ICC" = yes; then # Intel's compiler has a bug/misoptimization in checking for # division by NAN (NaN == 0), -mp1 fixes it, so add it to the CFLAGS. diff --git a/meson.build b/meson.build index a62d8171cc..9df8685dfd 100644 --- a/meson.build +++ b/meson.build @@ -1773,6 +1773,9 @@ negative_warning_flags = [ 'format-truncation', 'stringop-truncation', + # Suppress clang 16's strict warnings about function casts + 'cast-function-type-strict', + # To make warning_level=2 / -Wextra work, we'd need at least the following # 'clobbered', # 'missing-field-initializers', -- 2.35.1
