fix undefined behavior in memset due to missing sequence points

[musl] / configure

diff --git a/configure b/configure
index 81e90f7..02b736c 100755 (executable)
--- a/configure
+++ b/configure
@@ -31,7 +31,7 @@ Optional features:
   --enable-optimize=...   optimize listed components for speed over size [auto]
   --enable-debug          build with debugging information [disabled]
   --enable-warnings       build with recommended warnings flags [disabled]
-  --enable-visibility     use global visibility options to optimize PIC [auto]
+  --enable-visibility     use global visibility options to optimize PIC [no]
   --enable-wrapper=...    build given musl toolchain wrapper [auto]
   --disable-shared        inhibit building shared library [enabled]
   --disable-static        inhibit building static library [enabled]
@@ -135,7 +135,7 @@ target=
 optimize=auto
 debug=no
 warnings=no
-visibility=auto
+visibility=no
 shared=auto
 static=yes
 wrapper=auto
@@ -163,6 +163,7 @@ case "$arg" in
 --disable-debug|--enable-debug=no) debug=no ;;
 --enable-warnings|--enable-warnings=yes) warnings=yes ;;
 --disable-warnings|--enable-warnings=no) warnings=no ;;
+--enable-visibility=auto) visibility=auto ;;
 --enable-visibility|--enable-visibility=yes) visibility=yes ;;
 --disable-visibility|--enable-visibility=no) visibility=no ;;
 --enable-wrapper|--enable-wrapper=yes) wrapper=detect ;;
@@ -249,6 +250,7 @@ fi
 #
 tryflag   CFLAGS_TRY  -Werror=unknown-warning-option
 tryflag   CFLAGS_TRY  -Werror=unused-command-line-argument
+tryflag   CFLAGS_TRY  -Werror=ignored-optimization-argument
 tryldflag LDFLAGS_TRY -Werror=unknown-warning-option
 tryldflag LDFLAGS_TRY -Werror=unused-command-line-argument
 
@@ -504,6 +506,13 @@ tryflag CFLAGS_AUTO -Werror=implicit-int
 tryflag CFLAGS_AUTO -Werror=pointer-sign
 tryflag CFLAGS_AUTO -Werror=pointer-arith
 
+#
+# GCC ignores unused arguements by default, but Clang needs this extra
+# parameter to stop printing warnings about LDFLAGS passed during
+# compiling stage and CFLAGS passed during linking stage.
+#
+tryflag CFLAGS_AUTO -Qunused-arguments
+
 if test "x$warnings" = xyes ; then
 tryflag CFLAGS_AUTO -Wall
 tryflag CFLAGS_AUTO -Wno-parentheses
@@ -602,6 +611,10 @@ trycppif __ILP32__ "$t" && ARCH=x32
 fi
 
 if test "$ARCH" = "arm" ; then
+if trycppif __thumb2__ "$t" ; then
+tryflag CFLAGS_AUTO -Wa,-mimplicit-it=always
+tryflag CFLAGS_AUTO -Wa,-mthumb
+fi
 trycppif __ARMEB__ "$t" && SUBARCH=${SUBARCH}eb
 trycppif __ARM_PCS_VFP "$t" && SUBARCH=${SUBARCH}hf
 # Versions of clang up until at least 3.8 have the wrong constraint codes