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 (those
introduced by commit 1c27d16e, and some older ones).  Disable the new
warning for now, since otherwise buildfarm animal seawasp fails, and we
have no current plans to change our strategy for these callback function
types.

May be back-ed with other Clang/LLVM 16 changes around release
time.

Discussion: https://postgr.es/m/CA%2BhUKGJvX%2BL3aMN84ksT-cGy08VHErRNip3nV-WmTx7f6Pqhyw%40mail.gmail.com
(cherry picked from commit 101c37cd342a3ae134bb3e5e0abb14ae46692b56)

Author: Thomas Munro <[email protected]>
Author: Alexandra Wang <[email protected]>

diff --git a/configure b/configure
index 97053fb4e0ed77873cea15e1a79a1703dde1004c..2f10787c7dd289ba923b6c91873eafe263190143 100755 (executable)
--- a/configure
+++ b/configure
@@ -6411,6 +6411,50 @@ 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.in b/configure.in
index 385401a37d59b4508126a65ec6d76910fe231ed1..ce6a1f3e41aabee7f8ab2c4b68dd40890b9b3dca 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -553,6 +553,12 @@ 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
new file mode 100644 (file)index 0000000..e69de29