From 7144b5f275f380941bffca9509ecb97542c8e5ea Mon Sep 17 00:00:00 2001
From: Stephanos Ioannidis <root@stephanos.io>
Date: Mon, 7 Jun 2021 15:13:19 +0900
Subject: newlib: Add libstdc++ nano-specific CXXFLAGS

This commit adds a new config that can be used to specify the target
CXXFLAGS specific to the libstdc++ newlib-nano variant.

By default, this config is set to specify the `-fno-exceptions` option,
which disables C++ exception handling support and greatly reduces the
compiled binary size.

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

diff --git a/config/comp_libs/newlib-nano.in b/config/comp_libs/newlib-nano.in
index 0d80c89..5a81fde 100644
--- a/config/comp_libs/newlib-nano.in
+++ b/config/comp_libs/newlib-nano.in
@@ -18,6 +18,14 @@ config NEWLIB_NANO_GCC_LIBSTDCXX
       This option compiles an additional target libstdc++ for use with
       newlib-nano.
 
+config NEWLIB_NANO_GCC_LIBSTDCXX_TARGET_CXXFLAGS
+    string
+    prompt "Target CXXFLAGS for libstdc++ newlib-nano variant"
+    default "-fno-exceptions"
+    help
+      Used to add extra CXXFLAGS when compiling the target libstdc++
+      newlib-nano library (e.g. -fno-exceptions).
+
 config NEWLIB_NANO_INSTALL_IN_TARGET
     bool
     prompt "Additionally install newlib-nano libs into TARGET dir"
diff --git a/scripts/build/companion_libs/350-newlib_nano.sh b/scripts/build/companion_libs/350-newlib_nano.sh
index d109070..2d9de1b 100644
--- a/scripts/build/companion_libs/350-newlib_nano.sh
+++ b/scripts/build/companion_libs/350-newlib_nano.sh
@@ -67,6 +67,9 @@ do_cc_libstdcxx_newlib_nano()
 	if [ "${CT_LIBC_NEWLIB_NANO_ENABLE_TARGET_OPTSPACE}" = "y" ]; then
 	    final_opts+=( "enable_optspace=yes" )
 	fi
+        if [ -n "${CT_NEWLIB_NANO_GCC_LIBSTDCXX_TARGET_CXXFLAGS}" ]; then
+            final_opts+=( "extra_cxxflags_for_target=${CT_NEWLIB_NANO_GCC_LIBSTDCXX_TARGET_CXXFLAGS}" )
+        fi
 
         if [ "${CT_BARE_METAL}" = "y" ]; then
             final_opts+=( "mode=baremetal" )
-- 
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