first implementation of unrestricted static scoping

lparser.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.h,v 1.33 2001/08/10 20:53:03 roberto Exp roberto $
+** $Id: lparser.h,v 1.34 2001/08/27 15:16:28 roberto Exp $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -7,11 +7,24 @@
 #ifndef lparser_h
 #define lparser_h
 
+#include "llimits.h"
 #include "lobject.h"
 #include "ltable.h"
 #include "lzio.h"
 
 
+
+/* small implementation of bit arrays */
+
+#define BPW	(CHAR_BIT*sizeof(unsigned int))  /* bits per word */
+
+#define words2bits(b)	(((b)-1)/BPW + 1)
+
+#define setbit(a, b)	((a)[(b)/BPW] |= (1 << (b)%BPW))
+#define resetbit(a, b)	((a)[(b)/BPW] &= ~((1 << (b)%BPW)))
+#define testbit(a, b)	((a)[(b)/BPW] & (1 << (b)%BPW))
+
+
 /*
 ** Expression descriptor
 */
@@ -21,8 +34,9 @@ typedef enum {
   VNIL,
   VNUMBER,	/* n = value */
   VK,		/* info = index of constant in `k' */
-  VGLOBAL,	/* info = index of global name in `k' */
   VLOCAL,	/* info = local register */
+  VUPVAL,       /* info = index of upvalue in `upvalues' */
+  VGLOBAL,	/* info = index of global name in `k' */
   VINDEXED,	/* info = table register; aux = index register (or `k') */
   VRELOCABLE,	/* info = instruction pc */
   VNONRELOC,	/* info = result register */
@@ -63,6 +77,8 @@ typedef struct FuncState {
   struct Breaklabel *bl;  /* chain of breakable blocks */
   expdesc upvalues[MAXUPVALUES];  /* upvalues */
   int actloc[MAXLOCALS];  /* local-variable stack (indices to locvars) */
+  unsigned int wasup[words2bits(MAXLOCALS)];  /* bit array to mark whether a
+                             local variable was used as upvalue at some level */
 } FuncState;