[LIBC] Use RT_USING_LIBC instead of libs option for each compiler

components/libc/SConscript

 # for libc component
 import os
-Import('RTT_ROOT')
+Import('rtconfig')
+
+from building import *
 
 objs = []
-list = os.listdir(os.path.join(RTT_ROOT, 'components', 'libc'))
 
-for d in list:
-    path = os.path.join(RTT_ROOT, 'components', 'libc', d)
-    if os.path.isfile(os.path.join(path, 'SConscript')):
-        objs = objs + SConscript(os.path.join(d, 'SConscript'))
+if GetDepend('RT_USING_LIBC'):
+    if rtconfig.PLATFORM == 'gcc':
+        objs = objs + SConscript('newlib/SConscript')
+    elif rtconfig.PLATFORM == 'armcc':
+        objs = objs + SConscript('armlibc/SConscript')
+else:
+    if rtconfig.PLATFORM == 'gcc':
+        objs = objs + SConscript('minilibc/SConscript')
 
 Return('objs')

components/libc/armlibc/SConscript

-Import('rtconfig')
 from building import *
 
-if GetDepend('RT_USING_ARM_LIBC') and rtconfig.CROSS_TOOL != 'keil':
-    print '================ERROR=============================='
-    print 'Please use ARM CC compiler if using ARM C library'
-    print '==================================================='
-    exit(0)
-
-cwd = GetCurrentDir()
 src	= Glob('*.c')
+cwd = GetCurrentDir()
+
 CPPPATH = [cwd]
+CPPDEFINES = ['RT_USING_ARM_LIBC']
 
-group = DefineGroup('libc', src, depend = ['RT_USING_ARM_LIBC'], CPPPATH = CPPPATH)
+group = DefineGroup('libc', src, depend = ['RT_USING_LIBC'], 
+	CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
 
 Return('group')

components/libc/minilibc/SConscript

@@ -2,12 +2,12 @@ Import('RTT_ROOT')
 from building import *
 
 src	= Glob('*.c')
-CPPPATH = [RTT_ROOT + '/components/libc/minilibc']
+cwd = GetCurrentDir()
+
+CPPPATH = [cwd]
 CPPDEFINES = ['RT_USING_MINILIBC']
-group = DefineGroup('minilibc', src, 
-	depend = ['RT_USING_MINILIBC'], 
-	CPPPATH = CPPPATH,
-	CPPDEFINES = CPPDEFINES
-	)
+
+group = DefineGroup('libc', src, depend = ['RT_USING_MINILIBC'],
+	CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES)
 
 Return('group')

components/libc/newlib/SConscript

-Import('rtconfig')
 from building import *
 
-if GetDepend('RT_USING_NEWLIB') and rtconfig.CROSS_TOOL != 'gcc':
-    print '================ERROR============================'
-    print 'Please use GNU GCC compiler if using newlib'
-    print '================================================='
-    exit(0)
-
+src	= Glob('*.c')
 cwd = GetCurrentDir()
-src = Glob('*.c')
+
 CPPPATH = [cwd]
+CPPDEFINES = ['RT_USING_NEWLIB']
 
 # link with libc and libm:
 # libm is a frequently used lib. Newlib is compiled with -ffunction-sections in
@@ -17,7 +12,7 @@ CPPPATH = [cwd]
 # been referenced. So setting this won't result in bigger text size.
 LIBS = ['c', 'm']
 
-group = DefineGroup('newlib', src, depend = ['RT_USING_NEWLIB'],
-                    CPPPATH = CPPPATH, LIBS = LIBS)
+group = DefineGroup('newlib', src, depend = ['RT_USING_LIBC'], 
+	CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES, LIBS = LIBS)
 
 Return('group')