Disable clang 16's -Wcast-function-type-strict.

macdice · adunstan · commit b4363fc66e64 · 2024-11-08T09:44:01.000+10:30
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 1c27d16, 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-patched 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 101c37c) Author: Thomas Munro <tmunro@postgresql.org> Author: Alexandra Wang <alexandra.wang.oss@gmail.com>
diff --git 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
@@ -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
