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133 lines
4.3 KiB
133 lines
4.3 KiB
/* |
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** $Id: lparser.h,v 1.76.1.1 2017/04/19 17:20:42 roberto Exp $ |
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** Lua Parser |
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** See Copyright Notice in lua.h |
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*/ |
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#ifndef lparser_h |
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#define lparser_h |
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#include "llimits.h" |
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#include "lobject.h" |
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#include "lzio.h" |
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/* |
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** Expression and variable descriptor. |
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** Code generation for variables and expressions can be delayed to allow |
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** optimizations; An 'expdesc' structure describes a potentially-delayed |
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** variable/expression. It has a description of its "main" value plus a |
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** list of conditional jumps that can also produce its value (generated |
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** by short-circuit operators 'and'/'or'). |
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*/ |
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/* kinds of variables/expressions */ |
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typedef enum { |
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VVOID, /* when 'expdesc' describes the last expression a list, |
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this kind means an empty list (so, no expression) */ |
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VNIL, /* constant nil */ |
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VTRUE, /* constant true */ |
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VFALSE, /* constant false */ |
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VK, /* constant in 'k'; info = index of constant in 'k' */ |
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VKFLT, /* floating constant; nval = numerical float value */ |
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VKINT, /* integer constant; nval = numerical integer value */ |
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VNONRELOC, /* expression has its value in a fixed register; |
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info = result register */ |
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VLOCAL, /* local variable; info = local register */ |
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VUPVAL, /* upvalue variable; info = index of upvalue in 'upvalues' */ |
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VINDEXED, /* indexed variable; |
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ind.vt = whether 't' is register or upvalue; |
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ind.t = table register or upvalue; |
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ind.idx = key's R/K index */ |
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VJMP, /* expression is a test/comparison; |
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info = pc of corresponding jump instruction */ |
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VRELOCABLE, /* expression can put result in any register; |
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info = instruction pc */ |
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VCALL, /* expression is a function call; info = instruction pc */ |
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VVARARG /* vararg expression; info = instruction pc */ |
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} expkind; |
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#define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXED) |
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#define vkisinreg(k) ((k) == VNONRELOC || (k) == VLOCAL) |
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typedef struct expdesc { |
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expkind k; |
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union { |
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lua_Integer ival; /* for VKINT */ |
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lua_Number nval; /* for VKFLT */ |
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int info; /* for generic use */ |
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struct { /* for indexed variables (VINDEXED) */ |
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short idx; /* index (R/K) */ |
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lu_byte t; /* table (register or upvalue) */ |
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lu_byte vt; /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */ |
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} ind; |
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} u; |
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int t; /* patch list of 'exit when true' */ |
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int f; /* patch list of 'exit when false' */ |
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} expdesc; |
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/* description of active local variable */ |
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typedef struct Vardesc { |
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short idx; /* variable index in stack */ |
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} Vardesc; |
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/* description of pending goto statements and label statements */ |
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typedef struct Labeldesc { |
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TString *name; /* label identifier */ |
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int pc; /* position in code */ |
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int line; /* line where it appeared */ |
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lu_byte nactvar; /* local level where it appears in current block */ |
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} Labeldesc; |
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/* list of labels or gotos */ |
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typedef struct Labellist { |
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Labeldesc *arr; /* array */ |
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int n; /* number of entries in use */ |
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int size; /* array size */ |
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} Labellist; |
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/* dynamic structures used by the parser */ |
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typedef struct Dyndata { |
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struct { /* list of active local variables */ |
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Vardesc *arr; |
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int n; |
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int size; |
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} actvar; |
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Labellist gt; /* list of pending gotos */ |
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Labellist label; /* list of active labels */ |
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} Dyndata; |
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/* control of blocks */ |
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struct BlockCnt; /* defined in lparser.c */ |
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/* state needed to generate code for a given function */ |
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typedef struct FuncState { |
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Proto *f; /* current function header */ |
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struct FuncState *prev; /* enclosing function */ |
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struct LexState *ls; /* lexical state */ |
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struct BlockCnt *bl; /* chain of current blocks */ |
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int pc; /* next position to code (equivalent to 'ncode') */ |
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int lasttarget; /* 'label' of last 'jump label' */ |
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int jpc; /* list of pending jumps to 'pc' */ |
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int nk; /* number of elements in 'k' */ |
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int np; /* number of elements in 'p' */ |
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int firstlocal; /* index of first local var (in Dyndata array) */ |
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short nlocvars; /* number of elements in 'f->locvars' */ |
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lu_byte nactvar; /* number of active local variables */ |
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lu_byte nups; /* number of upvalues */ |
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lu_byte freereg; /* first free register */ |
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} FuncState; |
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LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, |
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Dyndata *dyd, const char *name, int firstchar); |
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#endif
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