bpo-5755: Move -Wstrict-prototypes to CFLAGS_NODIST (GH-7395)

(cherry picked from commit e33648484775fa533fc8f1e5cc45f60061d29d54)

diff --git a/Misc/NEWS.d/next/Build/2018-06-04-21-34-34.bpo-5755.65GmCj.rst b/Misc/NEWS.d/next/Build/2018-06-04-21-34-34.bpo-5755.65GmCj.rst
new file mode 100644 (file)
index 0000000..8bcad44
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2018-06-04-21-34-34.bpo-5755.65GmCj.rst
@@ -0,0 +1,3 @@
+Move ``-Wstrict-prototypes`` option to ``CFLAGS_NODIST`` from ``OPT``. This
+option emitted annoying warnings when building extension modules written in
+C++.

diff --git a/configure b/configure
index f1f2daa3be999ca2bf876d6367a16fa5222622c2..7b7b6c82dfea13666a333cd9861afcbed5b08e5a 100755 (executable)
--- a/configure
+++ b/configure
@@ -6865,9 +6865,6 @@ if test "${OPT-unset}" = "unset"
 then
     case $GCC in
     yes)
-        if test "$CC" != 'g++' ; then
-           STRICT_PROTO="-Wstrict-prototypes"
-       fi
         # For gcc 4.x we need to use -fwrapv so lets check if its supported
         if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
            WRAP="-fwrapv"
@@ -6914,8 +6911,6 @@ then
            ;;
        esac
 
-       OPT="$OPT $STRICT_PROTO"
-
        case $ac_sys_system in
            SCO_SV*) OPT="$OPT -m486 -DSCO5"
            ;;
@@ -7324,6 +7319,47 @@ fi
     { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_enable_unreachable_code_warning" >&5
 $as_echo "$ac_cv_enable_unreachable_code_warning" >&6; }
 
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking if we can turn on $CC strict-prototypes warning" >&5
+$as_echo_n "checking if we can turn on $CC strict-prototypes warning... " >&6; }
+     ac_save_cc="$CC"
+     CC="$CC -Werror -Wstrict-prototypes"
+     if ${ac_cv_enable_enable_strict_prototypes_warning+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+       ac_cv_enable_strict_prototypes_warning=yes
+
+else
+
+       ac_cv_enable_strict_prototypes_warning=no
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+     CC="$ac_save_cc"
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_enable_strict_prototypes_warning" >&5
+$as_echo "$ac_cv_enable_strict_prototypes_warning" >&6; }
+
+    if test $ac_cv_enable_strict_prototypes_warning = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wstrict-prototypes"
+    fi
+
     # if using gcc on alpha, use -mieee to get (near) full IEEE 754
     # support.  Without this, treatment of subnormals doesn't follow
     # the standard.

diff --git a/configure.ac b/configure.ac
index 2e6d8500831affeebec7a2058c44a3b28b660e01..30d70cff2586e3dc7bb467e02eaef451f72987b1 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1464,9 +1464,6 @@ if test "${OPT-unset}" = "unset"
 then
     case $GCC in
     yes)
-        if test "$CC" != 'g++' ; then
-           STRICT_PROTO="-Wstrict-prototypes"
-       fi
         # For gcc 4.x we need to use -fwrapv so lets check if its supported
         if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then
            WRAP="-fwrapv"
@@ -1513,8 +1510,6 @@ then
            ;;
        esac
 
-       OPT="$OPT $STRICT_PROTO"
-
        case $ac_sys_system in
            SCO_SV*) OPT="$OPT -m486 -DSCO5"
            ;;
@@ -1741,6 +1736,26 @@ yes)
     fi
     AC_MSG_RESULT($ac_cv_enable_unreachable_code_warning)
 
+    AC_MSG_CHECKING(if we can turn on $CC strict-prototypes warning)
+     ac_save_cc="$CC"
+     CC="$CC -Werror -Wstrict-prototypes"
+     AC_CACHE_VAL(ac_cv_enable_enable_strict_prototypes_warning,
+       AC_COMPILE_IFELSE(
+         [
+       AC_LANG_PROGRAM([[]], [[]])
+     ],[
+       ac_cv_enable_strict_prototypes_warning=yes
+     ],[
+       ac_cv_enable_strict_prototypes_warning=no
+     ]))
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_enable_strict_prototypes_warning)
+
+    if test $ac_cv_enable_strict_prototypes_warning = yes
+    then
+      CFLAGS_NODIST="$CFLAGS_NODIST -Wstrict-prototypes"
+    fi
+
     # if using gcc on alpha, use -mieee to get (near) full IEEE 754
     # support.  Without this, treatment of subnormals doesn't follow
     # the standard.