add support of arm standard c library, support using armcc to compile lua

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2429 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/external/lua/README.TXT

@@ -2,7 +2,7 @@
 
 ## 简介
 RT-Thread中的Lua修改自[eLua](http://www.eluaproject.net/)的Lua-5.1.4版本。
-采用gcc工具链时，Lua依赖于newlib库，其它工具链暂时还不支持。
+采用gcc工具链时，Lua依赖于newlib库，采用keil时，Lua依赖于arm的标准c库。
 启动lua的RAM占用情况
     - 标准的lua        17.1904296875 KB
     - 优化的lua        5.01953125 KB
@@ -24,11 +24,12 @@ RT-Thread中的Lua修改自[eLua](http://www.eluaproject.net/)的Lua-5.1.4版本
     3.更多的配置项可以在luaconf.h中找到
 
 ## 开发相关
-    - 采用gcc工具链时，依赖于newlib，需在rtconfig.h中定义RT_USING_NEWLIB
+    - 采用gcc工具链时，依赖于newlib，需在rtconfig.h中定义RT_USING_NEWLIB  
+      采用keil工具链时，依赖于arm的标准c库，需在rtconfig.h中定义RT_USING_ARM_LIBC
     - 开启编译器对C99的支持，如MDK中，在C/C++选项的Misc Controls输入框中添加--c99
-    - 需要在链接脚本中定义_stext和_etext，.ordata*放在两者之间。
-      用于判断数据是read-only和writable。MDK中如何实现？？
-    - 添加新的模块，参见lexample.c
+    - 使用gcc时，需要在链接脚本中定义_stext和_etext，.ordata*放在两者之间。用于判断数据是read-only和writable  
+      使用keil时，需要在分散加载文件中把rodata放在ER_IROM1区
+    - 添加新的模块，参见exlibs/lexamplelib.c
     
 ## 目录说明
     - lua：从eLua获得Lua-5.1.4版本代码

components/external/lua/lua/compiler.h

@@ -0,0 +1,43 @@
+/**
+ * define start/end address of ro data.
+ * different compiler with different implementation.
+ */
+
+#ifndef __COMPILER_H__
+#define __COMPILER_H__
+
+#if defined(__CC_ARM)       // armcc
+
+#warning "Please check scatter file to ensure rodata is in ER_IROM1 region."
+
+/* symbols reference to the scatter file */
+extern char Image$$ER_IROM1$$Base;
+extern char Image$$ER_IROM1$$Limit;
+
+#define RODATA_START_ADDRESS        (&Image$$ER_IROM1$$Base)
+#define RODATA_END_ADDRESS          (&Image$$ER_IROM1$$Limit)
+
+#elif defined(__GNUC__)     // gcc
+
+#warning "Please check linker script to ensure rodata is between _stext and _etext."
+
+/* symbols defined in linker script */
+extern char _stext;
+extern char _etext;
+
+#define RODATA_START_ADDRESS        (&_stext)
+#define RODATA_END_ADDRESS          (&_etext)
+
+#else                       // other compilers
+
+/* Firstly, modify rodata's start/end address. Then, comment the line below */
+#error "Please modify RODATA_START_ADDRESS and RODATA_END_ADDRESS below */
+
+/* Perhaps you can use start/end address of flash */
+#define RODATA_START_ADDRESS        ((char*)0x08000000)
+#define RODATA_END_ADDRESS          ((char*)0x08080000)
+
+#endif
+
+#endif // __COMPILER_H__
+

components/external/lua/lua/lrotable.c

@@ -126,9 +126,10 @@ void luaR_getcstr(char *dest, const TString *src, size_t maxsize) {
 
 /* Return 1 if the given pointer is a rotable */
 #ifdef LUA_META_ROTABLES
-extern char _stext;
-extern char _etext;
+
+#include "compiler.h"
+
 int luaR_isrotable(void *p) {
-  return &_stext <= ( char* )p && ( char* )p <= &_etext;
+  return RODATA_START_ADDRESS <= (char*)p && (char*)p <= RODATA_END_ADDRESS;
 }
 #endif

components/external/lua/lua/lstring.c

@@ -100,14 +100,14 @@ static TString *luaS_newlstr_helper (lua_State *L, const char *str, size_t l, in
   return newlstr(L, str, l, h, readonly);  /* not found */
 }
 
-extern char _stext;
-extern char _etext;
-
 static int lua_is_ptr_in_ro_area(const char *p) {
 #ifdef LUA_CROSS_COMPILER
   return 0;
 #else
-  return p >= &_stext && p <= &_etext;
+
+#include "compiler.h"
+
+  return p >= RODATA_START_ADDRESS && p <= RODATA_END_ADDRESS;
 #endif
 }