scripts: Allow stripping target toolchain libraries

This commit adds an option to strip the target toolchain libraries
(e.g. libc, libstdc++) of any unneeded or debugging information.

Stripping is enabled by default as it is often desirable to reduce the
overall toolchain size when producing a release.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

config/global/paths.in

@@ -137,3 +137,11 @@ config STRIP_TARGET_TOOLCHAIN_EXECUTABLES
       An install-strip make target is provided that installs stripped
       executables, and may install libraries with unneeded or debugging
       sections stripped. 
+
+config STRIP_TARGET_TOOLCHAIN_LIBRARIES
+    bool
+    prompt "Strip target toolchain libraries"
+    default y
+    help
+      Ensures that the target toolchain libraries are stripped of any unneeded
+      or debugging information.

scripts/build/internals.sh

@@ -92,6 +92,19 @@ do_finish() {
         CT_Popd
     fi
 
+    # Strip target toolchain libraries
+    if [ "${CT_STRIP_TARGET_TOOLCHAIN_LIBRARIES}" = "y" ]; then
+        CT_DoLog INFO "Stripping all target toolchain libraries"
+        CT_Pushd "${CT_PREFIX_DIR}"
+
+        strip_target_lib "${CT_PREFIX_DIR}/${CT_TARGET}/lib" "*.a"
+        strip_target_lib "${CT_PREFIX_DIR}/${CT_TARGET}/lib" "*.o"
+        strip_target_lib "${CT_PREFIX_DIR}/lib/gcc/${CT_TARGET}/${gcc_version}" "*.a"
+        strip_target_lib "${CT_PREFIX_DIR}/lib/gcc/${CT_TARGET}/${gcc_version}" "*.o"
+
+        CT_Popd
+    fi
+
     if [ "${CT_BARE_METAL}" != "y" ]; then
         CT_DoLog EXTRA "Installing the populate helper"
         sed -r -e 's|@@CT_TARGET@@|'"${CT_TARGET}"'|g;' \
@@ -140,3 +153,17 @@ do_finish() {
 
     CT_EndStep
 }
+
+strip_target_lib()
+{
+    local strip_args
+
+    strip_args="-R .comment -R .note -R .debug_info -R .debug_aranges
+    -R .debug_pubnames -R .debug_pubtypes -R .debug_abbrev -R .debug_line
+    -R .debug_str -R .debug_ranges -R .debug_loc
+        "
+
+    find "$1" -name "$2" | while read target_lib; do
+        CT_DoExecLog ALL ${CT_TARGET}-objcopy ${strip_args} "${target_lib}"
+    done
+}