| /* | |
| ** $Id: lparser.h $ | |
| ** Lua Parser | |
| ** See Copyright Notice in lua.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 of 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; ival = numerical integer value */ | |
| VKSTR, /* string constant; strval = TString address; | |
| (string is fixed by the lexer) */ | |
| VNONRELOC, /* expression has its value in a fixed register; | |
| info = result register */ | |
| VLOCAL, /* local variable; var.ridx = register index; | |
| var.vidx = relative index in 'actvar.arr' */ | |
| VUPVAL, /* upvalue variable; info = index of upvalue in 'upvalues' */ | |
| VCONST, /* compile-time <const> variable; | |
| info = absolute index in 'actvar.arr' */ | |
| VINDEXED, /* indexed variable; | |
| ind.t = table register; | |
| ind.idx = key's R index */ | |
| VINDEXUP, /* indexed upvalue; | |
| ind.t = table upvalue; | |
| ind.idx = key's K index */ | |
| VINDEXI, /* indexed variable with constant integer; | |
| ind.t = table register; | |
| ind.idx = key's value */ | |
| VINDEXSTR, /* indexed variable with literal string; | |
| ind.t = table register; | |
| ind.idx = key's K index */ | |
| VJMP, /* expression is a test/comparison; | |
| info = pc of corresponding jump instruction */ | |
| VRELOC, /* 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; | |
| typedef struct expdesc { | |
| expkind k; | |
| union { | |
| lua_Integer ival; /* for VKINT */ | |
| lua_Number nval; /* for VKFLT */ | |
| TString *strval; /* for VKSTR */ | |
| int info; /* for generic use */ | |
| struct { /* for indexed variables */ | |
| short idx; /* index (R or "long" K) */ | |
| lu_byte t; /* table (register or upvalue) */ | |
| } ind; | |
| struct { /* for local variables */ | |
| lu_byte ridx; /* register holding the variable */ | |
| unsigned short vidx; /* compiler index (in 'actvar.arr') */ | |
| } var; | |
| } u; | |
| int t; /* patch list of 'exit when true' */ | |
| int f; /* patch list of 'exit when false' */ | |
| } expdesc; | |
| /* kinds of variables */ | |
| /* description of an active local variable */ | |
| typedef union Vardesc { | |
| struct { | |
| TValuefields; /* constant value (if it is a compile-time constant) */ | |
| lu_byte kind; | |
| lu_byte ridx; /* register holding the variable */ | |
| short pidx; /* index of the variable in the Proto's 'locvars' array */ | |
| TString *name; /* variable name */ | |
| } vd; | |
| TValue k; /* constant value (if any) */ | |
| } 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; /* number of active variables in that position */ | |
| lu_byte close; /* goto that escapes upvalues */ | |
| } 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 all 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 previousline; /* last line that was saved in 'lineinfo' */ | |
| int nk; /* number of elements in 'k' */ | |
| int np; /* number of elements in 'p' */ | |
| int nabslineinfo; /* number of elements in 'abslineinfo' */ | |
| int firstlocal; /* index of first local var (in Dyndata array) */ | |
| int firstlabel; /* index of first label (in 'dyd->label->arr') */ | |
| short ndebugvars; /* 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 */ | |
| lu_byte iwthabs; /* instructions issued since last absolute line info */ | |
| lu_byte needclose; /* function needs to close upvalues when returning */ | |
| } FuncState; | |
| LUAI_FUNC int luaY_nvarstack (FuncState *fs); | |
| LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, | |
| Dyndata *dyd, const char *name, int firstchar); | |