[libc][time] 细微调整time.c

components/libc/compilers/newlib/SConscript

@@ -4,17 +4,18 @@ Import('rtconfig')
 src = []
 cwd = GetCurrentDir()
 group = []
-
+LIBS = []
+CPPDEFINES = []
 CPPPATH = [cwd]
 
 if rtconfig.PLATFORM == 'gcc':
     if GetDepend('RT_USING_LIBC'):
-        CPPDEFINES = ['RT_USING_NEWLIB']
+        CPPDEFINES += ['RT_USING_NEWLIB']
         # link with libc and libm:
         # libm is a frequently used lib. Newlib is compiled with -ffunction-sections in
         # recent GCC tool chains. The linker would just link in the functions that have
         # been referenced. So setting this won't result in bigger text size.
-        LIBS = ['c', 'm']
+        LIBS += ['c', 'm']
 
         src += Glob('*.c')
         SrcRemove(src, ['minilib.c'])
@@ -22,8 +23,6 @@ if rtconfig.PLATFORM == 'gcc':
             SrcRemove(src, ['libc_syms.c'])
     else:
         src += ['minilib.c']
-        CPPDEFINES = []
-        LIBS = []
 
     group = DefineGroup('libc', src, depend = [], CPPPATH = CPPPATH, CPPDEFINES = CPPDEFINES, LIBS = LIBS)