[libc] remove strdup from rtthread.h (#6026)

add __STDC_LIMIT_MACROS macro in Keil
add RT_USING_LIBC in simulator
add _DLIB_ADD_EXTRA_SYMBOLS=0 in IAR

bsp/simulator/drivers/SConscript

@@ -8,7 +8,7 @@ src = ['board.c', 'uart_console.c']
 LIBS = []
 LIBPATH = []
 CPPPATH = [cwd]
-CPPDEFINES = []
+CPPDEFINES = ['RT_USING_LIBC']
 
 if rtconfig.CROSS_TOOL == 'msvc':
     CPPDEFINES += \

components/libc/compilers/armlibc/SConscript

@@ -4,7 +4,7 @@ Import('rtconfig')
 src   = Glob('*.c')
 group = []
 
-CPPDEFINES = ['RT_USING_ARM_LIBC', 'RT_USING_LIBC']
+CPPDEFINES = ['RT_USING_ARM_LIBC', 'RT_USING_LIBC', '__STDC_LIMIT_MACROS']
 
 if rtconfig.PLATFORM in ['armcc', 'armclang']:
     group = DefineGroup('Compiler', src, depend = [''], CPPDEFINES = CPPDEFINES)

components/libc/compilers/dlib/SConscript

@@ -4,7 +4,7 @@ Import('rtconfig')
 src   = Glob('*.c')
 group = []
 
-CPPDEFINES = ['RT_USING_DLIBC', 'RT_USING_LIBC']
+CPPDEFINES = ['RT_USING_DLIBC', 'RT_USING_LIBC', '_DLIB_ADD_EXTRA_SYMBOLS=0']
 
 if rtconfig.PLATFORM == 'iar':
     if GetDepend('DFS_USING_POSIX'):

include/rtthread.h

@@ -605,7 +605,8 @@ void *rt_memcpy(void *dest, const void *src, rt_ubase_t n);
 void *rt_memmove(void *dest, const void *src, rt_size_t n);
 rt_int32_t rt_memcmp(const void *cs, const void *ct, rt_size_t count);
 #endif /* RT_KSERVICE_USING_STDLIB_MEMORY */
-
+char *rt_strdup(const char *s);
+rt_size_t rt_strnlen(const char *s, rt_ubase_t maxlen);
 #ifndef RT_KSERVICE_USING_STDLIB
 char *rt_strstr(const char *str1, const char *str2);
 rt_int32_t rt_strcasecmp(const char *a, const char *b);
@@ -631,19 +632,6 @@ rt_size_t rt_strlen(const char *src);
 #define rt_strlen(src)              strlen(src)
 #endif /*RT_KSERVICE_USING_STDLIB*/
 
-char *rt_strdup(const char *s);
-
-#if !defined(RT_KSERVICE_USING_STDLIB) || defined(__ARMCC_VERSION)
-rt_size_t rt_strnlen(const char *s, rt_ubase_t maxlen);
-#else
-#define rt_strnlen(s, maxlen)       strnlen(s, maxlen)
-#endif /* !defined(RT_KSERVICE_USING_STDLIB) || defined(__ARMCC_VERSION) */
-
-#ifdef __ARMCC_VERSION
-/* MDK doesn't have these APIs */
-rt_size_t strnlen(const char *s, rt_size_t maxlen);
-#endif /* __ARMCC_VERSION */
-
 void rt_show_version(void);
 
 #ifdef RT_DEBUG