From a5f6fdc780d55f2bf2a1624815879e15c51082b5 Mon Sep 17 00:00:00 2001
From: guozhanxin <guozhanxin@rt-thread.com>
Date: Wed, 22 Dec 2021 00:39:08 +0800
Subject: [PATCH] add clang-arm support.

---
 .../stm32l496-ali-developer/board/SConscript  |  2 +-
 bsp/stm32/stm32l496-ali-developer/rtconfig.py | 35 +++++++++++++++++++
 components/drivers/spi/SConscript             |  2 +-
 .../libc/compilers/common/nogcc/SConscript    |  2 +-
 .../libc/compilers/gcc/newlib/SConscript      |  2 +-
 libcpu/arm/cortex-m4/SConscript               |  2 +-
 tools/building.py                             |  2 +-
 7 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/bsp/stm32/stm32l496-ali-developer/board/SConscript b/bsp/stm32/stm32l496-ali-developer/board/SConscript
index 4c26186b46..9298652b29 100644
--- a/bsp/stm32/stm32l496-ali-developer/board/SConscript
+++ b/bsp/stm32/stm32l496-ali-developer/board/SConscript
@@ -24,7 +24,7 @@ path += [cwd + '/ports']
 
 startup_path_prefix = SDK_LIB
 
-if rtconfig.CROSS_TOOL == 'gcc':
+if rtconfig.CROSS_TOOL == 'gcc' or rtconfig.CROSS_TOOL == 'clang':
     src += [startup_path_prefix + '/STM32L4xx_HAL/CMSIS/Device/ST/STM32L4xx/Source/Templates/gcc/startup_stm32l496xx.s']
 elif rtconfig.CROSS_TOOL == 'keil':
     src += [startup_path_prefix + '/STM32L4xx_HAL/CMSIS/Device/ST/STM32L4xx/Source/Templates/arm/startup_stm32l496xx.s']
diff --git a/bsp/stm32/stm32l496-ali-developer/rtconfig.py b/bsp/stm32/stm32l496-ali-developer/rtconfig.py
index b6c0783af5..439b79a3c3 100644
--- a/bsp/stm32/stm32l496-ali-developer/rtconfig.py
+++ b/bsp/stm32/stm32l496-ali-developer/rtconfig.py
@@ -24,6 +24,9 @@ elif CROSS_TOOL == 'keil':
 elif CROSS_TOOL == 'iar':
     PLATFORM    = 'iar'
     EXEC_PATH   = r'C:/Program Files (x86)/IAR Systems/Embedded Workbench 8.0'
+elif CROSS_TOOL == 'clang':
+    PLATFORM    = 'clang'
+    EXEC_PATH   = r'D:\envs\LLVMEmbeddedToolchainForArm-13.0.0\bin'
 
 if os.getenv('RTT_EXEC_PATH'):
     EXEC_PATH = os.getenv('RTT_EXEC_PATH')
@@ -176,6 +179,38 @@ elif PLATFORM == 'iar':
     EXEC_PATH = EXEC_PATH + '/arm/bin/'
     POST_ACTION = 'ielftool --bin $TARGET rtthread.bin'
 
+elif PLATFORM == 'clang':
+    # toolchains
+    PREFIX = 'llvm-'
+    CC = 'clang'
+    AS = 'clang'
+    AR = PREFIX + 'ar'
+    CXX = 'clang++'
+    LINK = 'clang'
+    TARGET_EXT = 'elf'
+    SIZE = PREFIX + 'size'
+    OBJDUMP = PREFIX + 'objdump'
+    OBJCPY = PREFIX + 'objcopy'
+
+    DEVICE = ' --config armv7em_hard_fpv4_sp_d16_nosys'
+    CFLAGS = DEVICE
+    AFLAGS = ' -c' + DEVICE + ' -Wa,-mimplicit-it=thumb ' ## -x assembler-with-cpp
+    LFLAGS = DEVICE + ' -Wl,--gc-sections,-Map=rt-thread.map,-u,Reset_Handler -T board/linker_scripts/link.lds'
+
+    CPATH = ''
+    LPATH = ''
+
+    if BUILD == 'debug':
+        CFLAGS += ' -O0 -gdwarf-2 -g'
+        AFLAGS += ' -gdwarf-2'
+    else:
+        CFLAGS += ' -O2'
+
+    CXXFLAGS = CFLAGS 
+
+    POST_ACTION = OBJCPY + ' -O binary $TARGET rtthread.bin\n' + SIZE + ' $TARGET \n'
+
+
 def dist_handle(BSP_ROOT, dist_dir):
     import sys
     cwd_path = os.getcwd()
diff --git a/components/drivers/spi/SConscript b/components/drivers/spi/SConscript
index d6cb93f7f1..da14ed5fef 100644
--- a/components/drivers/spi/SConscript
+++ b/components/drivers/spi/SConscript
@@ -25,7 +25,7 @@ if GetDepend('RT_USING_SFUD'):
     CPPPATH += [cwd + '/sfud/inc']
     if GetDepend('RT_SFUD_USING_SFDP'):
         src_device += ['sfud/src/sfud_sfdp.c']
-    if rtconfig.CROSS_TOOL == 'gcc':
+    if rtconfig.CROSS_TOOL == 'gcc' or rtconfig.CROSS_TOOL == 'clang':
         LOCAL_CCFLAGS += ' -std=c99'
     elif rtconfig.CROSS_TOOL == 'keil':
         if rtconfig.PLATFORM == 'armcc':
diff --git a/components/libc/compilers/common/nogcc/SConscript b/components/libc/compilers/common/nogcc/SConscript
index c766c8f82d..b144f1b3b4 100644
--- a/components/libc/compilers/common/nogcc/SConscript
+++ b/components/libc/compilers/common/nogcc/SConscript
@@ -10,6 +10,6 @@ group = []
 if GetDepend('RT_USING_LIBC'):
     src += Glob('*.c')
 
-if rtconfig.PLATFORM != 'gcc' or rtconfig.ARCH == 'sim':
+if (rtconfig.PLATFORM != 'gcc' and rtconfig.PLATFORM != 'clang') or rtconfig.ARCH == 'sim':
     group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH)
 Return('group')
diff --git a/components/libc/compilers/gcc/newlib/SConscript b/components/libc/compilers/gcc/newlib/SConscript
index 58672a0255..7ab0dd046b 100644
--- a/components/libc/compilers/gcc/newlib/SConscript
+++ b/components/libc/compilers/gcc/newlib/SConscript
@@ -7,7 +7,7 @@ group = []
 LIBS = ['m'] # link libm
 CPPPATH = [cwd]
 
-if rtconfig.PLATFORM == 'gcc':
+if rtconfig.PLATFORM == 'gcc' or rtconfig.PLATFORM == 'clang':
     if GetDepend('RT_USING_LIBC'):
         LIBS += ['c'] # link libc
         src += Glob('*.c')
diff --git a/libcpu/arm/cortex-m4/SConscript b/libcpu/arm/cortex-m4/SConscript
index 75f0d9a7cc..fd80cd2a68 100644
--- a/libcpu/arm/cortex-m4/SConscript
+++ b/libcpu/arm/cortex-m4/SConscript
@@ -14,7 +14,7 @@ if rtconfig.PLATFORM == 'armcc' or rtconfig.PLATFORM == 'armclang':
 if rtconfig.PLATFORM == 'armclang':
     src += Glob('*_rvds.S')
 
-if rtconfig.PLATFORM == 'gcc':
+if rtconfig.PLATFORM == 'gcc' or rtconfig.PLATFORM == 'clang':
     src += Glob('*_init.S')
     src += Glob('*_gcc.S')
 
diff --git a/tools/building.py b/tools/building.py
index 10641c11a9..52212bac9a 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -121,7 +121,7 @@ class Win32Spawn:
 def GenCconfigFile(env, BuildOptions):
     import rtconfig
 
-    if rtconfig.PLATFORM == 'gcc':
+    if rtconfig.PLATFORM == 'gcc' or rtconfig.PLATFORM == 'clang':
         contents = ''
         if not os.path.isfile('cconfig.h'):
             import gcc