[libc] Change libc stubs to compiler folder.

components/libc/compilers/minilibc/stdlib.c

@@ -0,0 +1,79 @@
+/*
+ * File      : stdlib.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2008, RT-Thread Development Team
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rt-thread.org/license/LICENSE
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2008-08-14     Bernard      the first version
+ */
+
+#include <rtthread.h>
+
+#if !defined (RT_USING_NEWLIB) && defined (RT_USING_MINILIBC)
+#include "stdlib.h"
+
+int atoi(const char* s)
+{
+	long int v=0;
+	int sign=1;
+	while ( *s == ' '  ||  (unsigned int)(*s - 9) < 5u) s++;
+	switch (*s)
+	{
+	case '-':
+		sign=-1;
+	case '+':
+		++s;
+	}
+	while ((unsigned int) (*s - '0') < 10u)
+	{
+		v=v*10+*s-'0';
+		++s;
+	}
+	return sign==-1?-v:v;
+}
+
+long int atol(const char* s) 
+{
+	long int v=0;
+	int sign=0;
+	while ( *s == ' '  ||  (unsigned int)(*s - 9) < 5u) ++s;
+	switch (*s) 
+	{
+		case '-': sign=-1;
+		case '+': ++s;
+	}
+	while ((unsigned int) (*s - '0') < 10u) 
+	{
+		v=v*10+*s-'0'; ++s;
+	}
+	return sign?-v:v;
+}
+
+#ifdef RT_USING_HEAP
+void *malloc(size_t size)
+{
+	return rt_malloc(size);
+}
+
+void free(void *ptr)
+{
+	rt_free(ptr);
+}
+
+void *realloc(void *ptr, size_t size)
+{
+	return rt_realloc(ptr, size);
+}
+
+void *calloc(size_t nelem, size_t elsize)
+{
+	return rt_calloc(nelem, elsize);
+}
+#endif
+
+#endif