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 df200bee311a2ecb9a84e7662a05f78f1e384f63..57ec071cf9bd7abf451023e752aedf95820b7749 100755 (executable)
--- a/configure
+++ b/configure
@@ -6384,6 +6384,51 @@ 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 ${CC} supports -Wformat-truncation, for NOT_THE_CFLAGS" >&5
@@ -7299,6 +7344,48 @@ fi
     BITCODE_CFLAGS="$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 0ca14d90a90dd64a9b4ed15e5c14fa4b0dade2c6..227bc896b69cc9d60a534f54eec532343283c26c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -542,6 +542,13 @@ 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])
@@ -604,6 +611,11 @@ 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"