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+/*
+** $Id: lparser.h,v 1.76 2015/12/30 18:16:13 roberto Exp $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lparser_h
+#define lparser_h
+
+#include "llimits.h"
+#include "lobject.h"
+#include "lzio.h"
+
+
+/*
+** Expression and variable descriptor.
+** Code generation for variables and expressions can be delayed to allow
+** optimizations; An 'expdesc' structure describes a potentially-delayed
+** variable/expression. It has a description of its "main" value plus a
+** list of conditional jumps that can also produce its value (generated
+** by short-circuit operators 'and'/'or').
+*/
+
+/* kinds of variables/expressions */
+typedef enum {
+ VVOID, /* when 'expdesc' describes the last expression a list,
+ this kind means an empty list (so, no expression) */
+ VNIL, /* constant nil */
+ VTRUE, /* constant true */
+ VFALSE, /* constant false */
+ VK, /* constant in 'k'; info = index of constant in 'k' */
+ VKFLT, /* floating constant; nval = numerical float value */
+ VKINT, /* integer constant; nval = numerical integer value */
+ VNONRELOC, /* expression has its value in a fixed register;
+ info = result register */
+ VLOCAL, /* local variable; info = local register */
+ VUPVAL, /* upvalue variable; info = index of upvalue in 'upvalues' */
+ VINDEXED, /* indexed variable;
+ ind.vt = whether 't' is register or upvalue;
+ ind.t = table register or upvalue;
+ ind.idx = key's R/K index */
+ VJMP, /* expression is a test/comparison;
+ info = pc of corresponding jump instruction */
+ VRELOCABLE, /* expression can put result in any register;
+ info = instruction pc */
+ VCALL, /* expression is a function call; info = instruction pc */
+ VVARARG /* vararg expression; info = instruction pc */
+} expkind;
+
+
+#define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXED)
+#define vkisinreg(k) ((k) == VNONRELOC || (k) == VLOCAL)
+
+typedef struct expdesc {
+ expkind k;
+ union {
+ lua_Integer ival; /* for VKINT */
+ lua_Number nval; /* for VKFLT */
+ int info; /* for generic use */
+ struct { /* for indexed variables (VINDEXED) */
+ short idx; /* index (R/K) */
+ lu_byte t; /* table (register or upvalue) */
+ lu_byte vt; /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
+ } ind;
+ } u;
+ int t; /* patch list of 'exit when true' */
+ int f; /* patch list of 'exit when false' */
+} expdesc;
+
+
+/* description of active local variable */
+typedef struct Vardesc {
+ short idx; /* variable index in stack */
+} Vardesc;
+
+
+/* description of pending goto statements and label statements */
+typedef struct Labeldesc {
+ TString *name; /* label identifier */
+ int pc; /* position in code */
+ int line; /* line where it appeared */
+ lu_byte nactvar; /* local level where it appears in current block */
+} Labeldesc;
+
+
+/* list of labels or gotos */
+typedef struct Labellist {
+ Labeldesc *arr; /* array */
+ int n; /* number of entries in use */
+ int size; /* array size */
+} Labellist;
+
+
+/* dynamic structures used by the parser */
+typedef struct Dyndata {
+ struct { /* list of active local variables */
+ Vardesc *arr;
+ int n;
+ int size;
+ } actvar;
+ Labellist gt; /* list of pending gotos */
+ Labellist label; /* list of active labels */
+} Dyndata;
+
+
+/* control of blocks */
+struct BlockCnt; /* defined in lparser.c */
+
+
+/* state needed to generate code for a given function */
+typedef struct FuncState {
+ Proto *f; /* current function header */
+ struct FuncState *prev; /* enclosing function */
+ struct LexState *ls; /* lexical state */
+ struct BlockCnt *bl; /* chain of current blocks */
+ int pc; /* next position to code (equivalent to 'ncode') */
+ int lasttarget; /* 'label' of last 'jump label' */
+ int jpc; /* list of pending jumps to 'pc' */
+ int nk; /* number of elements in 'k' */
+ int np; /* number of elements in 'p' */
+ int firstlocal; /* index of first local var (in Dyndata array) */
+ short nlocvars; /* number of elements in 'f->locvars' */
+ lu_byte nactvar; /* number of active local variables */
+ lu_byte nups; /* number of upvalues */
+ lu_byte freereg; /* first free register */
+} FuncState;
+
+
+LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
+ Dyndata *dyd, const char *name, int firstchar);
+
+
+#endif