add errno implementation in RT-Thread.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1682 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/net/lwip/src/lwipopts.h

@@ -3,9 +3,7 @@
 
 #include <rtconfig.h>
 
-#if defined(RT_USING_NEWLIB) || defined(RT_USING_MINILIBC)
 #define ERRNO						1
-#endif
 
 #define NO_SYS                      0
 #define LWIP_SOCKET                 1

include/rtthread.h

@@ -365,6 +365,12 @@ void rt_kprintf(const char *fmt, ...);
 
 rt_err_t rt_get_errno(void);
 void rt_set_errno(rt_err_t no);
+int *_rt_errno(void);
+#ifndef RT_USING_NEWLIB
+#ifndef errno
+#define errno	*_rt_errno()
+#endif
+#endif
 
 void* rt_memset(void *src, int c, rt_ubase_t n);
 void* rt_memcpy(void *dest, const void *src, rt_ubase_t n);

src/kservice.c

@@ -27,7 +27,7 @@
 
 #ifndef RT_USING_NEWLIB
 /* global errno in RT-Thread*/
-volatile int errno;
+static volatile int _errno;
 #else
 #include <errno.h>
 #endif
@@ -47,11 +47,11 @@ rt_err_t rt_get_errno(void)
 	if(rt_interrupt_get_nest() != 0)
 	{
 		/* it's in interrupt context */
-		return errno;
+		return _errno;
 	}
 
 	tid = rt_thread_self();
-	if (tid == RT_NULL) return errno;
+	if (tid == RT_NULL) return _errno;
 
 	return tid->error;
 }
@@ -68,16 +68,33 @@ void rt_set_errno(rt_err_t error)
 	if(rt_interrupt_get_nest() != 0)
 	{
 		/* it's in interrupt context */
-		errno = error;
+		_errno = error;
 		return;
 	}
 
 	tid = rt_thread_self();
-	if (tid == RT_NULL) { errno = error; return; }
+	if (tid == RT_NULL) { _errno = error; return; }
 
 	tid->error = error;
 }
 
+/**
+ * This function returns errno.
+ *
+ * @return the errno in the system
+ */
+int *_rt_errno(void)
+{
+	rt_thread_t tid;
+	
+	if (rt_interrupt_get_nest() != 0) return (int *)&_errno;
+
+	tid = rt_thread_self();
+	if (tid != RT_NULL) return (int *)&(tid->error);
+
+	return (int *)&_errno;
+}
+
 /**
  * This function will set the content of memory to specified value
  *