We need -Werror when testing whether -f or -m flags work.

Thank you, clang, for treating unknown -f flags as warnings, only
failing with them if run with -Werror, and spewing out warning messages
whenever they're used.

diff --git a/aclocal.m4 b/aclocal.m4
index 6b04a4c4ac914bf609880f3ab93ea158429c4640..ca78a02c98e8b247898ffbdc1cf63942fb31476f 100644 (file)
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -257,7 +257,18 @@ AC_DEFUN(AC_LBL_CHECK_COMPILER_OPT,
     [
        AC_MSG_CHECKING([whether the compiler supports the $2 option])
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error $2"
+       if expr "x$2" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error $2"
+       elif expr "x$2" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror $2"
+       elif expr "x$2" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror $2"
+       else
+           CFLAGS="$CFLAGS $2"
+       fi
        AC_TRY_COMPILE(
            [],
            [return 0],

diff --git a/configure b/configure
index f134ad4610bd57cb419da4443d81910ce7f16e7b..6566eda27f4601fcccfb19577bf03c57b3660610 100755 (executable)
--- a/configure
+++ b/configure
@@ -3349,7 +3349,18 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -ffloat-store option" >&5
 $as_echo_n "checking whether the compiler supports the -ffloat-store option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -ffloat-store"
+       if expr "x-ffloat-store" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -ffloat-store"
+       elif expr "x-ffloat-store" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -ffloat-store"
+       elif expr "x-ffloat-store" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -ffloat-store"
+       else
+           CFLAGS="$CFLAGS -ffloat-store"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7189,7 +7200,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wall option" >&5
 $as_echo_n "checking whether the compiler supports the -Wall option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wall"
+       if expr "x-Wall" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wall"
+       elif expr "x-Wall" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wall"
+       elif expr "x-Wall" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wall"
+       else
+           CFLAGS="$CFLAGS -Wall"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7221,7 +7243,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wmissing-prototypes option" >&5
 $as_echo_n "checking whether the compiler supports the -Wmissing-prototypes option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wmissing-prototypes"
+       if expr "x-Wmissing-prototypes" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wmissing-prototypes"
+       elif expr "x-Wmissing-prototypes" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wmissing-prototypes"
+       elif expr "x-Wmissing-prototypes" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wmissing-prototypes"
+       else
+           CFLAGS="$CFLAGS -Wmissing-prototypes"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7253,7 +7286,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wstrict-prototypes option" >&5
 $as_echo_n "checking whether the compiler supports the -Wstrict-prototypes option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wstrict-prototypes"
+       if expr "x-Wstrict-prototypes" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wstrict-prototypes"
+       elif expr "x-Wstrict-prototypes" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wstrict-prototypes"
+       elif expr "x-Wstrict-prototypes" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wstrict-prototypes"
+       else
+           CFLAGS="$CFLAGS -Wstrict-prototypes"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7285,7 +7329,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wwrite-strings option" >&5
 $as_echo_n "checking whether the compiler supports the -Wwrite-strings option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wwrite-strings"
+       if expr "x-Wwrite-strings" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wwrite-strings"
+       elif expr "x-Wwrite-strings" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wwrite-strings"
+       elif expr "x-Wwrite-strings" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wwrite-strings"
+       else
+           CFLAGS="$CFLAGS -Wwrite-strings"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7317,7 +7372,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wpointer-arith option" >&5
 $as_echo_n "checking whether the compiler supports the -Wpointer-arith option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wpointer-arith"
+       if expr "x-Wpointer-arith" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wpointer-arith"
+       elif expr "x-Wpointer-arith" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wpointer-arith"
+       elif expr "x-Wpointer-arith" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wpointer-arith"
+       else
+           CFLAGS="$CFLAGS -Wpointer-arith"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7349,7 +7415,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wcast-qual option" >&5
 $as_echo_n "checking whether the compiler supports the -Wcast-qual option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wcast-qual"
+       if expr "x-Wcast-qual" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wcast-qual"
+       elif expr "x-Wcast-qual" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wcast-qual"
+       elif expr "x-Wcast-qual" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wcast-qual"
+       else
+           CFLAGS="$CFLAGS -Wcast-qual"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7381,7 +7458,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wshadow option" >&5
 $as_echo_n "checking whether the compiler supports the -Wshadow option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wshadow"
+       if expr "x-Wshadow" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wshadow"
+       elif expr "x-Wshadow" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wshadow"
+       elif expr "x-Wshadow" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wshadow"
+       else
+           CFLAGS="$CFLAGS -Wshadow"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7413,7 +7501,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wdeclaration-after-statement option" >&5
 $as_echo_n "checking whether the compiler supports the -Wdeclaration-after-statement option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wdeclaration-after-statement"
+       if expr "x-Wdeclaration-after-statement" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wdeclaration-after-statement"
+       elif expr "x-Wdeclaration-after-statement" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wdeclaration-after-statement"
+       elif expr "x-Wdeclaration-after-statement" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wdeclaration-after-statement"
+       else
+           CFLAGS="$CFLAGS -Wdeclaration-after-statement"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7445,7 +7544,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -pedantic option" >&5
 $as_echo_n "checking whether the compiler supports the -pedantic option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -pedantic"
+       if expr "x-pedantic" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -pedantic"
+       elif expr "x-pedantic" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -pedantic"
+       elif expr "x-pedantic" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -pedantic"
+       else
+           CFLAGS="$CFLAGS -pedantic"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7477,7 +7587,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -Wold-style-definition option" >&5
 $as_echo_n "checking whether the compiler supports the -Wold-style-definition option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wold-style-definition"
+       if expr "x-Wold-style-definition" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -Wold-style-definition"
+       elif expr "x-Wold-style-definition" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wold-style-definition"
+       elif expr "x-Wold-style-definition" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -Wold-style-definition"
+       else
+           CFLAGS="$CFLAGS -Wold-style-definition"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
@@ -7509,7 +7630,18 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
        { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the compiler supports the -W option" >&5
 $as_echo_n "checking whether the compiler supports the -W option... " >&6; }
        save_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -W"
+       if expr "x-W" : "x-W.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS $ac_lbl_unknown_warning_option_error -W"
+       elif expr "x-W" : "x-f.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -W"
+       elif expr "x-W" : "x-m.*" >/dev/null
+       then
+           CFLAGS="$CFLAGS -Werror -W"
+       else
+           CFLAGS="$CFLAGS -W"
+       fi
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */