add porting codes of rt-thread (#494)

core/iwasm/libraries/lib-pthread/SConscript

@@ -0,0 +1,20 @@
+#
+# Copyright (c) 2021, RT-Thread Development Team
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+from building import *
+
+cwd     = GetCurrentDir()
+
+src = Split('''
+libc_pthread_wrapper.c
+''')
+
+CPPPATH = [cwd]
+
+
+group = DefineGroup('iwasm_libc_pthread', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')

core/iwasm/libraries/libc-builtin/SConscript

@@ -0,0 +1,24 @@
+#
+# Copyright (c) 2021, RT-Thread Development Team
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+from building import *
+
+cwd     = GetCurrentDir()
+
+#src = Split('''
+#libc_builtin_wrapper.c
+#''')
+
+src = Glob('*.c')
+
+CPPDEFINES = ['WASM_ENABLE_LIBC_BUILTIN=1']
+
+CPPPATH = [cwd]
+
+
+group = DefineGroup('iwasm_libc_builtin', src, depend = [''], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
+
+Return('group')

core/iwasm/libraries/libc-emcc/SConscript

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2021, RT-Thread Development Team
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+from building import *
+
+cwd     = GetCurrentDir()
+
+src = Split('''
+libc_emcc_wrapper.c
+''')
+
+CPPPATH = [cwd]
+
+group = DefineGroup('iwasm_libc_emcc', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')

core/iwasm/libraries/libc-wasi/SConscript

@@ -0,0 +1,34 @@
+#
+# Copyright (c) 2021, RT-Thread Development Team
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+from building import *
+import os
+
+cwd     = GetCurrentDir()
+
+src = Split('''
+''')
+
+CPPPATH = [cwd,
+        cwd+'/sandboxed-system-primitives/include',
+        cwd+'/sandboxed-system-primitives/src']
+
+def addSrcFiles(arr, path):
+    for f in os.listdir(path):
+        fpath = os.path.join(path, f);
+        if os.path.isfile(fpath):
+            ext = os.path.splitext(fpath)[-1]
+            if ext == '.c' or ext == '.cpp':
+                arr += [fpath]
+        elif os.path.isdir(fpath):
+            addSrcFiles(arr, fpath)
+
+
+addSrcFiles(src, cwd)
+
+group = DefineGroup('iwasm_libc_wasi', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')

core/iwasm/libraries/thread-mgr/SConscript

@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2021, RT-Thread Development Team
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+from building import *
+
+cwd     = GetCurrentDir()
+
+src = Split('''
+thread_manager.c
+''')
+
+CPPPATH = [cwd]
+
+group = DefineGroup('iwasm_lib_thread_mgr', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')