/* ** $Id: lparser.h,v 1.76.1.1 2017/04/19 17:20:42 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