first version of code optimizer

1 files changed, 73 insertions, 1 deletions

diff --git a/lparser.h b/lparser.h
index df25c6fa..aa47d0fd 100644
--- a/lparser.h
+++ b/lparser.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.h,v 1.4 1999/08/16 20:52:00 roberto Exp roberto $
+** $Id: lparser.h,v 1.5 1999/11/22 13:12:07 roberto Exp roberto $
 ** LL(1) Parser and code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -8,9 +8,81 @@
 #define lparser_h
 
 #include "lobject.h"
+#include "lopcodes.h"
 #include "lzio.h"
 
 
+/* maximum number of local variables */
+#ifndef MAXLOCALS
+#define MAXLOCALS 200  /* arbitrary limit (<=MAXARG_B) */
+#endif
+
+
+/* maximum number of upvalues */
+#ifndef MAXUPVALUES
+#define MAXUPVALUES 32  /* arbitrary limit (<=MAXARG_B) */
+#endif
+
+
+/* maximum number of variables in the left side of an assignment */
+#ifndef MAXVARSLH
+#define MAXVARSLH	100  /* arbitrary limit (<=MAXARG_B) */
+#endif
+
+
+/* maximum number of parameters in a function */
+#ifndef MAXPARAMS
+#define MAXPARAMS	100  /* arbitrary limit (<=MAXLOCALS) */
+#endif
+
+
+/* maximum stack size in a function */
+#ifndef MAXSTACK
+#define MAXSTACK	256  /* arbitrary limit (<=MAXARG_A) */
+#endif
+
+
+#if MAXLOCALS>MAXARG_U || MAXUPVALUES>MAXARG_B || MAXVARSLH>MAXARG_B || \
+    MAXPARAMS>MAXLOCALS || MAXSTACK>MAXARG_A || LFIELDS_PER_FLUSH>MAXARG_B
+#error invalid limits
+#endif
+
+
+
+/*
+** Variable descriptor:
+** must include an `exp' option because LL(1) cannot distinguish
+** between variables, upvalues and function calls on first sight.
+*/
+typedef enum {
+  VGLOBAL,  /* info is constant index of global name */
+  VLOCAL,   /* info is stack index */
+  VINDEXED, /* no info (table and index are on the stack) */
+  VEXP      /* info is pc index of a call (or 0 if exp is closed) */
+} varkind;
+
+typedef struct vardesc {
+  varkind k;
+  int info;
+} vardesc;
+
+
+/* state needed to generate code for a given function */
+typedef struct FuncState {
+  TProtoFunc *f;  /* current function header */
+  struct FuncState *prev;  /* enclosing function */
+  int pc;  /* next position to code */
+  int last_pc;  /* last instruction coded (for optimizations) */
+  int stacksize;  /* number of values on activation register */
+  int nlocalvar;  /* number of active local variables */
+  int nupvalues;  /* number of upvalues */
+  int nvars;  /* number of entries in f->locvars (-1 if no debug information) */
+  int lastsetline;  /* line where last SETLINE was issued */
+  vardesc upvalues[MAXUPVALUES];  /* upvalues */
+  TaggedString *localvar[MAXLOCALS];  /* store local variable names */
+} FuncState;
+
+
 TProtoFunc *luaY_parser (lua_State *L, ZIO *z);