Added additional newlib specific target flags with new option

LIBC_NEWLIB_TARGET_CFLAGS.

Signed-off-by: Jasmin Jessich <jasmin@anw.at>

config/libc/newlib.in

@@ -144,6 +144,20 @@ config LIBC_VERSION
       Enter the tag you want to use.
       Leave empty to use the 'head' of the repository.
 
+config LIBC_NEWLIB_TARGET_CFLAGS
+    string
+    prompt "Target CFLAGS for newlib"
+    default ""
+    help
+      Used to add specific options when compiling the target libraries
+      (eg. -ffunction-sections -fdata-sections), which can't be defined
+      in global TARGET_CFLAGS, because they shall be not used for the
+      gcc target libraries.
+      Note:  Both TARGET_CFLAGS and LIBC_NEWLIB_TARGET_CFLAGS are used
+             to compile the libraries.
+ 
+      Leave blank if you don't know better.
+
 comment "Architecture specific options"
 
 config ATMEL_AVR32_HEADERS

scripts/build/libc/newlib.sh

@@ -72,6 +72,7 @@ do_libc_start_files() {
 
 do_libc() {
     local -a newlib_opts
+    local cflags_for_target
 
     CT_DoStep INFO "Installing C library"
 
@@ -109,6 +110,8 @@ do_libc() {
 
     [ "${CT_LIBC_NEWLIB_ENABLE_TARGET_OPTSPACE}" = "y" ] && newlib_opts+=("--enable-target-optspace")
 
+    cflags_for_target="${CT_TARGET_CFLAGS} ${CT_LIBC_NEWLIB_TARGET_CFLAGS}"
+
     # Note: newlib handles the build/host/target a little bit differently
     # than one would expect:
     #   build  : not used
@@ -116,7 +119,7 @@ do_libc() {
     #   target : the machine newlib runs on
     CT_DoExecLog CFG                                    \
     CC_FOR_BUILD="${CT_BUILD}-gcc"                      \
-    CFLAGS_FOR_TARGET="${CT_TARGET_CFLAGS}"             \
+    CFLAGS_FOR_TARGET="${cflags_for_target}"            \
     AR=${CT_TARGET}-ar                                  \
     RANLIB=${CT_TARGET}-ranlib                          \
     "${CT_SRC_DIR}/newlib-${CT_LIBC_VERSION}/configure" \