From 4f5ba63c7c94b37515c2b3f3c4ae423585795d0c Mon Sep 17 00:00:00 2001
From: Meco Man <920369182@qq.com>
Date: Wed, 14 Jun 2023 00:03:38 -0400
Subject: [PATCH] [cpp] attach CXXFLAGS to reduce the resource consumptions

---
 bsp/k210/drivers/SConscript                   | 2 +-
 components/libc/cplusplus/Kconfig             | 4 ++++
 components/libc/cplusplus/SConscript          | 7 ++++++-
 components/libc/cplusplus/cpp11/gcc/__utils.h | 4 +---
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/bsp/k210/drivers/SConscript b/bsp/k210/drivers/SConscript
index 9d10702655..a118be7270 100644
--- a/bsp/k210/drivers/SConscript
+++ b/bsp/k210/drivers/SConscript
@@ -38,7 +38,7 @@ if GetDepend('RT_USING_PWM'):
 if GetDepend('RT_USING_WDT'):
     src += ['drv_wdt.c']
 
-group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH)
+group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH, CPPDEFINES=['NNCASE_NO_EXCEPTIONS'])
 
 objs = [group]
 
diff --git a/components/libc/cplusplus/Kconfig b/components/libc/cplusplus/Kconfig
index e049f65629..1dcc6f389c 100644
--- a/components/libc/cplusplus/Kconfig
+++ b/components/libc/cplusplus/Kconfig
@@ -16,4 +16,8 @@ if RT_USING_CPLUSPLUS
         bool "Enable RT-Thread APIs C++ wrapper"
         default n
 
+    config RT_USING_CPP_EXCEPTIONS
+        bool "Enable C++ exceptions (will increase overhead)"
+        default n
+
 endif
diff --git a/components/libc/cplusplus/SConscript b/components/libc/cplusplus/SConscript
index a7829cea6d..2f280892f4 100644
--- a/components/libc/cplusplus/SConscript
+++ b/components/libc/cplusplus/SConscript
@@ -5,8 +5,13 @@ Import('rtconfig')
 cwd     = GetCurrentDir()
 src     = ['cxx_crt_init.c', 'cxx_crt.cpp']
 CPPPATH = [cwd]
+CXXFLAGS = ''
 
-group = DefineGroup('CPP', src, depend=['RT_USING_CPLUSPLUS'], CPPPATH=CPPPATH)
+
+if rtconfig.PLATFORM in ['gcc', 'armclang', 'llvm-arm'] and not GetDepend('RT_USING_CPP_EXCEPTIONS'):
+    CXXFLAGS += ' -fno-exceptions -fno-rtti -ffunction-sections -fdata-sections -Wl,--gc-sections' # reduce resource consumptions
+
+group = DefineGroup('CPP', src, depend=['RT_USING_CPLUSPLUS'], CPPPATH=CPPPATH, CXXFLAGS=CXXFLAGS)
 
 list = os.listdir(cwd)
 for d in list:
diff --git a/components/libc/cplusplus/cpp11/gcc/__utils.h b/components/libc/cplusplus/cpp11/gcc/__utils.h
index f9a3c93796..304d789ab5 100644
--- a/components/libc/cplusplus/cpp11/gcc/__utils.h
+++ b/components/libc/cplusplus/cpp11/gcc/__utils.h
@@ -17,11 +17,9 @@
 
 #include <rtthread.h>
 
-#define RT_USING_CPP_EXCEPTION
-
 inline void throw_system_error(int err, const char *what_msg)
 {
-#ifdef RT_USING_CPP_EXCEPTION
+#ifdef RT_USING_CPP_EXCEPTIONS
     throw std::system_error(std::error_code(err, std::system_category()), what_msg);
 #else
     (void)err;