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Diffstat (limited to 'src/lib/lua/lparser.h')
-rw-r--r-- | src/lib/lua/lparser.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/lib/lua/lparser.h b/src/lib/lua/lparser.h new file mode 100644 index 0000000..02e9b03 --- /dev/null +++ b/src/lib/lua/lparser.h @@ -0,0 +1,133 @@ +/* +** $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 |