Disable -Wdeprecated-non-prototype in the back branches.

There doesn't seem to be any good ABI-preserving way to silence
clang 15's -Wdeprecated-non-prototype warnings about our tree-walk
APIs.  While we've fixed it properly in HEAD, the only way to not
see hundreds of these in the back branches is to disable the
warnings.  We're not going to do anything about them, so we might
as well disable them.

I noticed that we also get some of these warnings about fmgr.c's
support for V0 function call convention, in branches before v10
where we removed that.  That's another area we aren't going to
change, so turning off the warning seems fine for that too.

Per project policy, this is a candidate for back-patching into
out-of-support branches: it suppresses annoying compiler warnings
but changes no behavior.  Hence, back-patch all the way to 9.2.

Discussion: https://postgr.es/m/CA+hUKGKpHPDTv67Y+s6yiC8KH5OXeDg6a-twWo_xznKTcG0kSA@mail.gmail.com

diff --git a/configure b/configure
index 453f1fb4380919f0aa0f34ee26161c8e9e64b731..c47cb62e608a7a2e85c764350e0ac0748343f17e 100755 (executable)
--- a/configure
+++ b/configure
@@ -6399,6 +6399,51 @@ fi
   if test -n "$NOT_THE_CFLAGS"; then
     CFLAGS="$CFLAGS -Wno-compound-token-split-by-macro"
   fi
+  # Similarly remove clang 15+'s deprecated-non-prototype, as it warns about
+  # tree-walking APIs that we can't reasonably change in the back branches.
+  NOT_THE_CFLAGS=""
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wdeprecated-non-prototype, for NOT_THE_CFLAGS" >&5
+$as_echo_n "checking whether ${CC} supports -Wdeprecated-non-prototype, for NOT_THE_CFLAGS... " >&6; }
+if ${pgac_cv_prog_CC_cflags__Wdeprecated_non_prototype+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CC}
+CFLAGS="${NOT_THE_CFLAGS} -Wdeprecated-non-prototype"
+ac_save_c_werror_flag=$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__Wdeprecated_non_prototype=yes
+else
+  pgac_cv_prog_CC_cflags__Wdeprecated_non_prototype=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: $pgac_cv_prog_CC_cflags__Wdeprecated_non_prototype" >&5
+$as_echo "$pgac_cv_prog_CC_cflags__Wdeprecated_non_prototype" >&6; }
+if test x"$pgac_cv_prog_CC_cflags__Wdeprecated_non_prototype" = x"yes"; then
+  NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -Wdeprecated-non-prototype"
+fi
+
+
+  if test -n "$NOT_THE_CFLAGS"; then
+    CFLAGS="$CFLAGS -Wno-deprecated-non-prototype"
+  fi
   # Similarly disable useless truncation warnings from gcc 8+
   NOT_THE_CFLAGS=""
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wformat-truncation, for NOT_THE_CFLAGS" >&5
@@ -7314,6 +7359,48 @@ fi
     BITCODE_CFLAGS="$BITCODE_CFLAGS -Wno-compound-token-split-by-macro"
   fi
   NOT_THE_CFLAGS=""
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CLANG} supports -Wdeprecated-non-prototype, for NOT_THE_CFLAGS" >&5
+$as_echo_n "checking whether ${CLANG} supports -Wdeprecated-non-prototype, for NOT_THE_CFLAGS... " >&6; }
+if ${pgac_cv_prog_CLANG_cflags__Wdeprecated_non_prototype+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+pgac_save_CC=$CC
+CC=${CLANG}
+CFLAGS="${NOT_THE_CFLAGS} -Wdeprecated-non-prototype"
+ac_save_c_werror_flag=$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_CLANG_cflags__Wdeprecated_non_prototype=yes
+else
+  pgac_cv_prog_CLANG_cflags__Wdeprecated_non_prototype=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: $pgac_cv_prog_CLANG_cflags__Wdeprecated_non_prototype" >&5
+$as_echo "$pgac_cv_prog_CLANG_cflags__Wdeprecated_non_prototype" >&6; }
+if test x"$pgac_cv_prog_CLANG_cflags__Wdeprecated_non_prototype" = x"yes"; then
+  NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -Wdeprecated-non-prototype"
+fi
+
+  if test -n "$NOT_THE_CFLAGS"; then
+    BITCODE_CFLAGS="$BITCODE_CFLAGS -Wno-deprecated-non-prototype"
+  fi
+  NOT_THE_CFLAGS=""
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CLANG} supports -Wformat-truncation, for NOT_THE_CFLAGS" >&5
 $as_echo_n "checking whether ${CLANG} supports -Wformat-truncation, for NOT_THE_CFLAGS... " >&6; }
 if ${pgac_cv_prog_CLANG_cflags__Wformat_truncation+:} false; then :

diff --git a/configure.ac b/configure.ac
index 58a862f269005ce9bff93ed0ebc179bf1060b6a2..99352d3e14d385bdcf0d6987abf9e9821fac2a98 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -545,6 +545,13 @@ if test "$GCC" = yes -a "$ICC" = no; then
   if test -n "$NOT_THE_CFLAGS"; then
     CFLAGS="$CFLAGS -Wno-compound-token-split-by-macro"
   fi
+  # Similarly remove clang 15+'s deprecated-non-prototype, as it warns about
+  # tree-walking APIs that we can't reasonably change in the back branches.
+  NOT_THE_CFLAGS=""
+  PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wdeprecated-non-prototype])
+  if test -n "$NOT_THE_CFLAGS"; then
+    CFLAGS="$CFLAGS -Wno-deprecated-non-prototype"
+  fi
   # Similarly disable useless truncation warnings from gcc 8+
   NOT_THE_CFLAGS=""
   PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wformat-truncation])
@@ -607,6 +614,11 @@ if test "$with_llvm" = yes ; then
     BITCODE_CFLAGS="$BITCODE_CFLAGS -Wno-compound-token-split-by-macro"
   fi
   NOT_THE_CFLAGS=""
+  PGAC_PROG_VARCC_VARFLAGS_OPT(CLANG, NOT_THE_CFLAGS, [-Wdeprecated-non-prototype])
+  if test -n "$NOT_THE_CFLAGS"; then
+    BITCODE_CFLAGS="$BITCODE_CFLAGS -Wno-deprecated-non-prototype"
+  fi
+  NOT_THE_CFLAGS=""
   PGAC_PROG_VARCC_VARFLAGS_OPT(CLANG, NOT_THE_CFLAGS, [-Wformat-truncation])
   if test -n "$NOT_THE_CFLAGS"; then
     BITCODE_CFLAGS="$BITCODE_CFLAGS -Wno-format-truncation"