diff options
Diffstat (limited to 'Build/source/libs/lua52/lua52-src/src/lparser.c')
| -rw-r--r-- | Build/source/libs/lua52/lua52-src/src/lparser.c | 1638 |
1 files changed, 0 insertions, 1638 deletions
diff --git a/Build/source/libs/lua52/lua52-src/src/lparser.c b/Build/source/libs/lua52/lua52-src/src/lparser.c deleted file mode 100644 index 9e1a9ca2cfe..00000000000 --- a/Build/source/libs/lua52/lua52-src/src/lparser.c +++ /dev/null @@ -1,1638 +0,0 @@ -/* -** $Id: lparser.c,v 2.130.1.1 2013/04/12 18:48:47 roberto Exp $ -** Lua Parser -** See Copyright Notice in lua.h -*/ - - -#include <string.h> - -#define lparser_c -#define LUA_CORE - -#include "lua.h" - -#include "lcode.h" -#include "ldebug.h" -#include "ldo.h" -#include "lfunc.h" -#include "llex.h" -#include "lmem.h" -#include "lobject.h" -#include "lopcodes.h" -#include "lparser.h" -#include "lstate.h" -#include "lstring.h" -#include "ltable.h" - - - -/* maximum number of local variables per function (must be smaller - than 250, due to the bytecode format) */ -#define MAXVARS 200 - - -#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) - - - -/* -** nodes for block list (list of active blocks) -*/ -typedef struct BlockCnt { - struct BlockCnt *previous; /* chain */ - short firstlabel; /* index of first label in this block */ - short firstgoto; /* index of first pending goto in this block */ - lu_byte nactvar; /* # active locals outside the block */ - lu_byte upval; /* true if some variable in the block is an upvalue */ - lu_byte isloop; /* true if `block' is a loop */ -} BlockCnt; - - - -/* -** prototypes for recursive non-terminal functions -*/ -static void statement (LexState *ls); -static void expr (LexState *ls, expdesc *v); - - -static void anchor_token (LexState *ls) { - /* last token from outer function must be EOS */ - lua_assert(ls->fs != NULL || ls->t.token == TK_EOS); - if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) { - TString *ts = ls->t.seminfo.ts; - luaX_newstring(ls, getstr(ts), ts->tsv.len); - } -} - - -/* semantic error */ -static l_noret semerror (LexState *ls, const char *msg) { - ls->t.token = 0; /* remove 'near to' from final message */ - luaX_syntaxerror(ls, msg); -} - - -static l_noret error_expected (LexState *ls, int token) { - luaX_syntaxerror(ls, - luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token))); -} - - -static l_noret errorlimit (FuncState *fs, int limit, const char *what) { - lua_State *L = fs->ls->L; - const char *msg; - int line = fs->f->linedefined; - const char *where = (line == 0) - ? "main function" - : luaO_pushfstring(L, "function at line %d", line); - msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s", - what, limit, where); - luaX_syntaxerror(fs->ls, msg); -} - - -static void checklimit (FuncState *fs, int v, int l, const char *what) { - if (v > l) errorlimit(fs, l, what); -} - - -static int testnext (LexState *ls, int c) { - if (ls->t.token == c) { - luaX_next(ls); - return 1; - } - else return 0; -} - - -static void check (LexState *ls, int c) { - if (ls->t.token != c) - error_expected(ls, c); -} - - -static void checknext (LexState *ls, int c) { - check(ls, c); - luaX_next(ls); -} - - -#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } - - - -static void check_match (LexState *ls, int what, int who, int where) { - if (!testnext(ls, what)) { - if (where == ls->linenumber) - error_expected(ls, what); - else { - luaX_syntaxerror(ls, luaO_pushfstring(ls->L, - "%s expected (to close %s at line %d)", - luaX_token2str(ls, what), luaX_token2str(ls, who), where)); - } - } -} - - -static TString *str_checkname (LexState *ls) { - TString *ts; - check(ls, TK_NAME); - ts = ls->t.seminfo.ts; - luaX_next(ls); - return ts; -} - - -static void init_exp (expdesc *e, expkind k, int i) { - e->f = e->t = NO_JUMP; - e->k = k; - e->u.info = i; -} - - -static void codestring (LexState *ls, expdesc *e, TString *s) { - init_exp(e, VK, luaK_stringK(ls->fs, s)); -} - - -static void checkname (LexState *ls, expdesc *e) { - codestring(ls, e, str_checkname(ls)); -} - - -static int registerlocalvar (LexState *ls, TString *varname) { - FuncState *fs = ls->fs; - Proto *f = fs->f; - int oldsize = f->sizelocvars; - luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, - LocVar, SHRT_MAX, "local variables"); - while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL; - f->locvars[fs->nlocvars].varname = varname; - luaC_objbarrier(ls->L, f, varname); - return fs->nlocvars++; -} - - -static void new_localvar (LexState *ls, TString *name) { - FuncState *fs = ls->fs; - Dyndata *dyd = ls->dyd; - int reg = registerlocalvar(ls, name); - checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, - MAXVARS, "local variables"); - luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1, - dyd->actvar.size, Vardesc, MAX_INT, "local variables"); - dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg); -} - - -static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) { - new_localvar(ls, luaX_newstring(ls, name, sz)); -} - -#define new_localvarliteral(ls,v) \ - new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1) - - -static LocVar *getlocvar (FuncState *fs, int i) { - int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx; - lua_assert(idx < fs->nlocvars); - return &fs->f->locvars[idx]; -} - - -static void adjustlocalvars (LexState *ls, int nvars) { - FuncState *fs = ls->fs; - fs->nactvar = cast_byte(fs->nactvar + nvars); - for (; nvars; nvars--) { - getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc; - } -} - - -static void removevars (FuncState *fs, int tolevel) { - fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel); - while (fs->nactvar > tolevel) - getlocvar(fs, --fs->nactvar)->endpc = fs->pc; -} - - -static int searchupvalue (FuncState *fs, TString *name) { - int i; - Upvaldesc *up = fs->f->upvalues; - for (i = 0; i < fs->nups; i++) { - if (luaS_eqstr(up[i].name, name)) return i; - } - return -1; /* not found */ -} - - -static int newupvalue (FuncState *fs, TString *name, expdesc *v) { - Proto *f = fs->f; - int oldsize = f->sizeupvalues; - checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues"); - luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues, - Upvaldesc, MAXUPVAL, "upvalues"); - while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL; - f->upvalues[fs->nups].instack = (v->k == VLOCAL); - f->upvalues[fs->nups].idx = cast_byte(v->u.info); - f->upvalues[fs->nups].name = name; - luaC_objbarrier(fs->ls->L, f, name); - return fs->nups++; -} - - -static int searchvar (FuncState *fs, TString *n) { - int i; - for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) { - if (luaS_eqstr(n, getlocvar(fs, i)->varname)) - return i; - } - return -1; /* not found */ -} - - -/* - Mark block where variable at given level was defined - (to emit close instructions later). -*/ -static void markupval (FuncState *fs, int level) { - BlockCnt *bl = fs->bl; - while (bl->nactvar > level) bl = bl->previous; - bl->upval = 1; -} - - -/* - Find variable with given name 'n'. If it is an upvalue, add this - upvalue into all intermediate functions. -*/ -static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { - if (fs == NULL) /* no more levels? */ - return VVOID; /* default is global */ - else { - int v = searchvar(fs, n); /* look up locals at current level */ - if (v >= 0) { /* found? */ - init_exp(var, VLOCAL, v); /* variable is local */ - if (!base) - markupval(fs, v); /* local will be used as an upval */ - return VLOCAL; - } - else { /* not found as local at current level; try upvalues */ - int idx = searchupvalue(fs, n); /* try existing upvalues */ - if (idx < 0) { /* not found? */ - if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */ - return VVOID; /* not found; is a global */ - /* else was LOCAL or UPVAL */ - idx = newupvalue(fs, n, var); /* will be a new upvalue */ - } - init_exp(var, VUPVAL, idx); - return VUPVAL; - } - } -} - - -static void singlevar (LexState *ls, expdesc *var) { - TString *varname = str_checkname(ls); - FuncState *fs = ls->fs; - if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */ - expdesc key; - singlevaraux(fs, ls->envn, var, 1); /* get environment variable */ - lua_assert(var->k == VLOCAL || var->k == VUPVAL); - codestring(ls, &key, varname); /* key is variable name */ - luaK_indexed(fs, var, &key); /* env[varname] */ - } -} - - -static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { - FuncState *fs = ls->fs; - int extra = nvars - nexps; - if (hasmultret(e->k)) { - extra++; /* includes call itself */ - if (extra < 0) extra = 0; - luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ - if (extra > 1) luaK_reserveregs(fs, extra-1); - } - else { - if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ - if (extra > 0) { - int reg = fs->freereg; - luaK_reserveregs(fs, extra); - luaK_nil(fs, reg, extra); - } - } -} - - -static void enterlevel (LexState *ls) { - lua_State *L = ls->L; - ++L->nCcalls; - checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels"); -} - - -#define leavelevel(ls) ((ls)->L->nCcalls--) - - -static void closegoto (LexState *ls, int g, Labeldesc *label) { - int i; - FuncState *fs = ls->fs; - Labellist *gl = &ls->dyd->gt; - Labeldesc *gt = &gl->arr[g]; - lua_assert(luaS_eqstr(gt->name, label->name)); - if (gt->nactvar < label->nactvar) { - TString *vname = getlocvar(fs, gt->nactvar)->varname; - const char *msg = luaO_pushfstring(ls->L, - "<goto %s> at line %d jumps into the scope of local " LUA_QS, - getstr(gt->name), gt->line, getstr(vname)); - semerror(ls, msg); - } - luaK_patchlist(fs, gt->pc, label->pc); - /* remove goto from pending list */ - for (i = g; i < gl->n - 1; i++) - gl->arr[i] = gl->arr[i + 1]; - gl->n--; -} - - -/* -** try to close a goto with existing labels; this solves backward jumps -*/ -static int findlabel (LexState *ls, int g) { - int i; - BlockCnt *bl = ls->fs->bl; - Dyndata *dyd = ls->dyd; - Labeldesc *gt = &dyd->gt.arr[g]; - /* check labels in current block for a match */ - for (i = bl->firstlabel; i < dyd->label.n; i++) { - Labeldesc *lb = &dyd->label.arr[i]; - if (luaS_eqstr(lb->name, gt->name)) { /* correct label? */ - if (gt->nactvar > lb->nactvar && - (bl->upval || dyd->label.n > bl->firstlabel)) - luaK_patchclose(ls->fs, gt->pc, lb->nactvar); - closegoto(ls, g, lb); /* close it */ - return 1; - } - } - return 0; /* label not found; cannot close goto */ -} - - -static int newlabelentry (LexState *ls, Labellist *l, TString *name, - int line, int pc) { - int n = l->n; - luaM_growvector(ls->L, l->arr, n, l->size, - Labeldesc, SHRT_MAX, "labels/gotos"); - l->arr[n].name = name; - l->arr[n].line = line; - l->arr[n].nactvar = ls->fs->nactvar; - l->arr[n].pc = pc; - l->n++; - return n; -} - - -/* -** check whether new label 'lb' matches any pending gotos in current -** block; solves forward jumps -*/ -static void findgotos (LexState *ls, Labeldesc *lb) { - Labellist *gl = &ls->dyd->gt; - int i = ls->fs->bl->firstgoto; - while (i < gl->n) { - if (luaS_eqstr(gl->arr[i].name, lb->name)) - closegoto(ls, i, lb); - else - i++; - } -} - - -/* -** "export" pending gotos to outer level, to check them against -** outer labels; if the block being exited has upvalues, and -** the goto exits the scope of any variable (which can be the -** upvalue), close those variables being exited. -*/ -static void movegotosout (FuncState *fs, BlockCnt *bl) { - int i = bl->firstgoto; - Labellist *gl = &fs->ls->dyd->gt; - /* correct pending gotos to current block and try to close it - with visible labels */ - while (i < gl->n) { - Labeldesc *gt = &gl->arr[i]; - if (gt->nactvar > bl->nactvar) { - if (bl->upval) - luaK_patchclose(fs, gt->pc, bl->nactvar); - gt->nactvar = bl->nactvar; - } - if (!findlabel(fs->ls, i)) - i++; /* move to next one */ - } -} - - -static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) { - bl->isloop = isloop; - bl->nactvar = fs->nactvar; - bl->firstlabel = fs->ls->dyd->label.n; - bl->firstgoto = fs->ls->dyd->gt.n; - bl->upval = 0; - bl->previous = fs->bl; - fs->bl = bl; - lua_assert(fs->freereg == fs->nactvar); -} - - -/* -** create a label named "break" to resolve break statements -*/ -static void breaklabel (LexState *ls) { - TString *n = luaS_new(ls->L, "break"); - int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc); - findgotos(ls, &ls->dyd->label.arr[l]); -} - -/* -** generates an error for an undefined 'goto'; choose appropriate -** message when label name is a reserved word (which can only be 'break') -*/ -static l_noret undefgoto (LexState *ls, Labeldesc *gt) { - const char *msg = isreserved(gt->name) - ? "<%s> at line %d not inside a loop" - : "no visible label " LUA_QS " for <goto> at line %d"; - msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line); - semerror(ls, msg); -} - - -static void leaveblock (FuncState *fs) { - BlockCnt *bl = fs->bl; - LexState *ls = fs->ls; - if (bl->previous && bl->upval) { - /* create a 'jump to here' to close upvalues */ - int j = luaK_jump(fs); - luaK_patchclose(fs, j, bl->nactvar); - luaK_patchtohere(fs, j); - } - if (bl->isloop) - breaklabel(ls); /* close pending breaks */ - fs->bl = bl->previous; - removevars(fs, bl->nactvar); - lua_assert(bl->nactvar == fs->nactvar); - fs->freereg = fs->nactvar; /* free registers */ - ls->dyd->label.n = bl->firstlabel; /* remove local labels */ - if (bl->previous) /* inner block? */ - movegotosout(fs, bl); /* update pending gotos to outer block */ - else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */ - undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */ -} - - -/* -** adds a new prototype into list of prototypes -*/ -static Proto *addprototype (LexState *ls) { - Proto *clp; - lua_State *L = ls->L; - FuncState *fs = ls->fs; - Proto *f = fs->f; /* prototype of current function */ - if (fs->np >= f->sizep) { - int oldsize = f->sizep; - luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions"); - while (oldsize < f->sizep) f->p[oldsize++] = NULL; - } - f->p[fs->np++] = clp = luaF_newproto(L); - luaC_objbarrier(L, f, clp); - return clp; -} - - -/* -** codes instruction to create new closure in parent function. -** The OP_CLOSURE instruction must use the last available register, -** so that, if it invokes the GC, the GC knows which registers -** are in use at that time. -*/ -static void codeclosure (LexState *ls, expdesc *v) { - FuncState *fs = ls->fs->prev; - init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1)); - luaK_exp2nextreg(fs, v); /* fix it at the last register */ -} - - -static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { - lua_State *L = ls->L; - Proto *f; - fs->prev = ls->fs; /* linked list of funcstates */ - fs->ls = ls; - ls->fs = fs; - fs->pc = 0; - fs->lasttarget = 0; - fs->jpc = NO_JUMP; - fs->freereg = 0; - fs->nk = 0; - fs->np = 0; - fs->nups = 0; - fs->nlocvars = 0; - fs->nactvar = 0; - fs->firstlocal = ls->dyd->actvar.n; - fs->bl = NULL; - f = fs->f; - f->source = ls->source; - f->maxstacksize = 2; /* registers 0/1 are always valid */ - fs->h = luaH_new(L); - /* anchor table of constants (to avoid being collected) */ - sethvalue2s(L, L->top, fs->h); - incr_top(L); - enterblock(fs, bl, 0); -} - - -static void close_func (LexState *ls) { - lua_State *L = ls->L; - FuncState *fs = ls->fs; - Proto *f = fs->f; - luaK_ret(fs, 0, 0); /* final return */ - leaveblock(fs); - luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); - f->sizecode = fs->pc; - luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); - f->sizelineinfo = fs->pc; - luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue); - f->sizek = fs->nk; - luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); - f->sizep = fs->np; - luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); - f->sizelocvars = fs->nlocvars; - luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); - f->sizeupvalues = fs->nups; - lua_assert(fs->bl == NULL); - ls->fs = fs->prev; - /* last token read was anchored in defunct function; must re-anchor it */ - anchor_token(ls); - L->top--; /* pop table of constants */ - luaC_checkGC(L); -} - - - -/*============================================================*/ -/* GRAMMAR RULES */ -/*============================================================*/ - - -/* -** check whether current token is in the follow set of a block. -** 'until' closes syntactical blocks, but do not close scope, -** so it handled in separate. -*/ -static int block_follow (LexState *ls, int withuntil) { - switch (ls->t.token) { - case TK_ELSE: case TK_ELSEIF: - case TK_END: case TK_EOS: - return 1; - case TK_UNTIL: return withuntil; - default: return 0; - } -} - - -static void statlist (LexState *ls) { - /* statlist -> { stat [`;'] } */ - while (!block_follow(ls, 1)) { - if (ls->t.token == TK_RETURN) { - statement(ls); - return; /* 'return' must be last statement */ - } - statement(ls); - } -} - - -static void fieldsel (LexState *ls, expdesc *v) { - /* fieldsel -> ['.' | ':'] NAME */ - FuncState *fs = ls->fs; - expdesc key; - luaK_exp2anyregup(fs, v); - luaX_next(ls); /* skip the dot or colon */ - checkname(ls, &key); - luaK_indexed(fs, v, &key); -} - - -static void yindex (LexState *ls, expdesc *v) { - /* index -> '[' expr ']' */ - luaX_next(ls); /* skip the '[' */ - expr(ls, v); - luaK_exp2val(ls->fs, v); - checknext(ls, ']'); -} - - -/* -** {====================================================================== -** Rules for Constructors -** ======================================================================= -*/ - - -struct ConsControl { - expdesc v; /* last list item read */ - expdesc *t; /* table descriptor */ - int nh; /* total number of `record' elements */ - int na; /* total number of array elements */ - int tostore; /* number of array elements pending to be stored */ -}; - - -static void recfield (LexState *ls, struct ConsControl *cc) { - /* recfield -> (NAME | `['exp1`]') = exp1 */ - FuncState *fs = ls->fs; - int reg = ls->fs->freereg; - expdesc key, val; - int rkkey; - if (ls->t.token == TK_NAME) { - checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); - checkname(ls, &key); - } - else /* ls->t.token == '[' */ - yindex(ls, &key); - cc->nh++; - checknext(ls, '='); - rkkey = luaK_exp2RK(fs, &key); - expr(ls, &val); - luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val)); - fs->freereg = reg; /* free registers */ -} - - -static void closelistfield (FuncState *fs, struct ConsControl *cc) { - if (cc->v.k == VVOID) return; /* there is no list item */ - luaK_exp2nextreg(fs, &cc->v); - cc->v.k = VVOID; - if (cc->tostore == LFIELDS_PER_FLUSH) { - luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ - cc->tostore = 0; /* no more items pending */ - } -} - - -static void lastlistfield (FuncState *fs, struct ConsControl *cc) { - if (cc->tostore == 0) return; - if (hasmultret(cc->v.k)) { - luaK_setmultret(fs, &cc->v); - luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET); - cc->na--; /* do not count last expression (unknown number of elements) */ - } - else { - if (cc->v.k != VVOID) - luaK_exp2nextreg(fs, &cc->v); - luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); - } -} - - -static void listfield (LexState *ls, struct ConsControl *cc) { - /* listfield -> exp */ - expr(ls, &cc->v); - checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); - cc->na++; - cc->tostore++; -} - - -static void field (LexState *ls, struct ConsControl *cc) { - /* field -> listfield | recfield */ - switch(ls->t.token) { - case TK_NAME: { /* may be 'listfield' or 'recfield' */ - if (luaX_lookahead(ls) != '=') /* expression? */ - listfield(ls, cc); - else - recfield(ls, cc); - break; - } - case '[': { - recfield(ls, cc); - break; - } - default: { - listfield(ls, cc); - break; - } - } -} - - -static void constructor (LexState *ls, expdesc *t) { - /* constructor -> '{' [ field { sep field } [sep] ] '}' - sep -> ',' | ';' */ - FuncState *fs = ls->fs; - int line = ls->linenumber; - int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); - struct ConsControl cc; - cc.na = cc.nh = cc.tostore = 0; - cc.t = t; - init_exp(t, VRELOCABLE, pc); - init_exp(&cc.v, VVOID, 0); /* no value (yet) */ - luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */ - checknext(ls, '{'); - do { - lua_assert(cc.v.k == VVOID || cc.tostore > 0); - if (ls->t.token == '}') break; - closelistfield(fs, &cc); - field(ls, &cc); - } while (testnext(ls, ',') || testnext(ls, ';')); - check_match(ls, '}', '{', line); - lastlistfield(fs, &cc); - SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ - SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */ -} - -/* }====================================================================== */ - - - -static void parlist (LexState *ls) { - /* parlist -> [ param { `,' param } ] */ - FuncState *fs = ls->fs; - Proto *f = fs->f; - int nparams = 0; - f->is_vararg = 0; - if (ls->t.token != ')') { /* is `parlist' not empty? */ - do { - switch (ls->t.token) { - case TK_NAME: { /* param -> NAME */ - new_localvar(ls, str_checkname(ls)); - nparams++; - break; - } - case TK_DOTS: { /* param -> `...' */ - luaX_next(ls); - f->is_vararg = 1; - break; - } - default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected"); - } - } while (!f->is_vararg && testnext(ls, ',')); - } - adjustlocalvars(ls, nparams); - f->numparams = cast_byte(fs->nactvar); - luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ -} - - -static void body (LexState *ls, expdesc *e, int ismethod, int line) { - /* body -> `(' parlist `)' block END */ - FuncState new_fs; - BlockCnt bl; - new_fs.f = addprototype(ls); - new_fs.f->linedefined = line; - open_func(ls, &new_fs, &bl); - checknext(ls, '('); - if (ismethod) { - new_localvarliteral(ls, "self"); /* create 'self' parameter */ - adjustlocalvars(ls, 1); - } - parlist(ls); - checknext(ls, ')'); - statlist(ls); - new_fs.f->lastlinedefined = ls->linenumber; - check_match(ls, TK_END, TK_FUNCTION, line); - codeclosure(ls, e); - close_func(ls); -} - - -static int explist (LexState *ls, expdesc *v) { - /* explist -> expr { `,' expr } */ - int n = 1; /* at least one expression */ - expr(ls, v); - while (testnext(ls, ',')) { - luaK_exp2nextreg(ls->fs, v); - expr(ls, v); - n++; - } - return n; -} - - -static void funcargs (LexState *ls, expdesc *f, int line) { - FuncState *fs = ls->fs; - expdesc args; - int base, nparams; - switch (ls->t.token) { - case '(': { /* funcargs -> `(' [ explist ] `)' */ - luaX_next(ls); - if (ls->t.token == ')') /* arg list is empty? */ - args.k = VVOID; - else { - explist(ls, &args); - luaK_setmultret(fs, &args); - } - check_match(ls, ')', '(', line); - break; - } - case '{': { /* funcargs -> constructor */ - constructor(ls, &args); - break; - } - case TK_STRING: { /* funcargs -> STRING */ - codestring(ls, &args, ls->t.seminfo.ts); - luaX_next(ls); /* must use `seminfo' before `next' */ - break; - } - default: { - luaX_syntaxerror(ls, "function arguments expected"); - } - } - lua_assert(f->k == VNONRELOC); - base = f->u.info; /* base register for call */ - if (hasmultret(args.k)) - nparams = LUA_MULTRET; /* open call */ - else { - if (args.k != VVOID) - luaK_exp2nextreg(fs, &args); /* close last argument */ - nparams = fs->freereg - (base+1); - } - init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); - luaK_fixline(fs, line); - fs->freereg = base+1; /* call remove function and arguments and leaves - (unless changed) one result */ -} - - - - -/* -** {====================================================================== -** Expression parsing -** ======================================================================= -*/ - - -static void primaryexp (LexState *ls, expdesc *v) { - /* primaryexp -> NAME | '(' expr ')' */ - switch (ls->t.token) { - case '(': { - int line = ls->linenumber; - luaX_next(ls); - expr(ls, v); - check_match(ls, ')', '(', line); - luaK_dischargevars(ls->fs, v); - return; - } - case TK_NAME: { - singlevar(ls, v); - return; - } - default: { - luaX_syntaxerror(ls, "unexpected symbol"); - } - } -} - - -static void suffixedexp (LexState *ls, expdesc *v) { - /* suffixedexp -> - primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */ - FuncState *fs = ls->fs; - int line = ls->linenumber; - primaryexp(ls, v); - for (;;) { - switch (ls->t.token) { - case '.': { /* fieldsel */ - fieldsel(ls, v); - break; - } - case '[': { /* `[' exp1 `]' */ - expdesc key; - luaK_exp2anyregup(fs, v); - yindex(ls, &key); - luaK_indexed(fs, v, &key); - break; - } - case ':': { /* `:' NAME funcargs */ - expdesc key; - luaX_next(ls); - checkname(ls, &key); - luaK_self(fs, v, &key); - funcargs(ls, v, line); - break; - } - case '(': case TK_STRING: case '{': { /* funcargs */ - luaK_exp2nextreg(fs, v); - funcargs(ls, v, line); - break; - } - default: return; - } - } -} - - -static void simpleexp (LexState *ls, expdesc *v) { - /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... | - constructor | FUNCTION body | suffixedexp */ - switch (ls->t.token) { - case TK_NUMBER: { - init_exp(v, VKNUM, 0); - v->u.nval = ls->t.seminfo.r; - break; - } - case TK_STRING: { - codestring(ls, v, ls->t.seminfo.ts); - break; - } - case TK_NIL: { - init_exp(v, VNIL, 0); - break; - } - case TK_TRUE: { - init_exp(v, VTRUE, 0); - break; - } - case TK_FALSE: { - init_exp(v, VFALSE, 0); - break; - } - case TK_DOTS: { /* vararg */ - FuncState *fs = ls->fs; - check_condition(ls, fs->f->is_vararg, - "cannot use " LUA_QL("...") " outside a vararg function"); - init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0)); - break; - } - case '{': { /* constructor */ - constructor(ls, v); - return; - } - case TK_FUNCTION: { - luaX_next(ls); - body(ls, v, 0, ls->linenumber); - return; - } - default: { - suffixedexp(ls, v); - return; - } - } - luaX_next(ls); -} - - -static UnOpr getunopr (int op) { - switch (op) { - case TK_NOT: return OPR_NOT; - case '-': return OPR_MINUS; - case '#': return OPR_LEN; - default: return OPR_NOUNOPR; - } -} - - -static BinOpr getbinopr (int op) { - switch (op) { - case '+': return OPR_ADD; - case '-': return OPR_SUB; - case '*': return OPR_MUL; - case '/': return OPR_DIV; - case '%': return OPR_MOD; - case '^': return OPR_POW; - case TK_CONCAT: return OPR_CONCAT; - case TK_NE: return OPR_NE; - case TK_EQ: return OPR_EQ; - case '<': return OPR_LT; - case TK_LE: return OPR_LE; - case '>': return OPR_GT; - case TK_GE: return OPR_GE; - case TK_AND: return OPR_AND; - case TK_OR: return OPR_OR; - default: return OPR_NOBINOPR; - } -} - - -static const struct { - lu_byte left; /* left priority for each binary operator */ - lu_byte right; /* right priority */ -} priority[] = { /* ORDER OPR */ - {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `*' `/' `%' */ - {10, 9}, {5, 4}, /* ^, .. (right associative) */ - {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */ - {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */ - {2, 2}, {1, 1} /* and, or */ -}; - -#define UNARY_PRIORITY 8 /* priority for unary operators */ - - -/* -** subexpr -> (simpleexp | unop subexpr) { binop subexpr } -** where `binop' is any binary operator with a priority higher than `limit' -*/ -static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { - BinOpr op; - UnOpr uop; - enterlevel(ls); - uop = getunopr(ls->t.token); - if (uop != OPR_NOUNOPR) { - int line = ls->linenumber; - luaX_next(ls); - subexpr(ls, v, UNARY_PRIORITY); - luaK_prefix(ls->fs, uop, v, line); - } - else simpleexp(ls, v); - /* expand while operators have priorities higher than `limit' */ - op = getbinopr(ls->t.token); - while (op != OPR_NOBINOPR && priority[op].left > limit) { - expdesc v2; - BinOpr nextop; - int line = ls->linenumber; - luaX_next(ls); - luaK_infix(ls->fs, op, v); - /* read sub-expression with higher priority */ - nextop = subexpr(ls, &v2, priority[op].right); - luaK_posfix(ls->fs, op, v, &v2, line); - op = nextop; - } - leavelevel(ls); - return op; /* return first untreated operator */ -} - - -static void expr (LexState *ls, expdesc *v) { - subexpr(ls, v, 0); -} - -/* }==================================================================== */ - - - -/* -** {====================================================================== -** Rules for Statements -** ======================================================================= -*/ - - -static void block (LexState *ls) { - /* block -> statlist */ - FuncState *fs = ls->fs; - BlockCnt bl; - enterblock(fs, &bl, 0); - statlist(ls); - leaveblock(fs); -} - - -/* -** structure to chain all variables in the left-hand side of an -** assignment -*/ -struct LHS_assign { - struct LHS_assign *prev; - expdesc v; /* variable (global, local, upvalue, or indexed) */ -}; - - -/* -** check whether, in an assignment to an upvalue/local variable, the -** upvalue/local variable is begin used in a previous assignment to a -** table. If so, save original upvalue/local value in a safe place and -** use this safe copy in the previous assignment. -*/ -static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { - FuncState *fs = ls->fs; - int extra = fs->freereg; /* eventual position to save local variable */ - int conflict = 0; - for (; lh; lh = lh->prev) { /* check all previous assignments */ - if (lh->v.k == VINDEXED) { /* assigning to a table? */ - /* table is the upvalue/local being assigned now? */ - if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) { - conflict = 1; - lh->v.u.ind.vt = VLOCAL; - lh->v.u.ind.t = extra; /* previous assignment will use safe copy */ - } - /* index is the local being assigned? (index cannot be upvalue) */ - if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) { - conflict = 1; - lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */ - } - } - } - if (conflict) { - /* copy upvalue/local value to a temporary (in position 'extra') */ - OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; - luaK_codeABC(fs, op, extra, v->u.info, 0); - luaK_reserveregs(fs, 1); - } -} - - -static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { - expdesc e; - check_condition(ls, vkisvar(lh->v.k), "syntax error"); - if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */ - struct LHS_assign nv; - nv.prev = lh; - suffixedexp(ls, &nv.v); - if (nv.v.k != VINDEXED) - check_conflict(ls, lh, &nv.v); - checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS, - "C levels"); - assignment(ls, &nv, nvars+1); - } - else { /* assignment -> `=' explist */ - int nexps; - checknext(ls, '='); - nexps = explist(ls, &e); - if (nexps != nvars) { - adjust_assign(ls, nvars, nexps, &e); - if (nexps > nvars) - ls->fs->freereg -= nexps - nvars; /* remove extra values */ - } - else { - luaK_setoneret(ls->fs, &e); /* close last expression */ - luaK_storevar(ls->fs, &lh->v, &e); - return; /* avoid default */ - } - } - init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ - luaK_storevar(ls->fs, &lh->v, &e); -} - - -static int cond (LexState *ls) { - /* cond -> exp */ - expdesc v; - expr(ls, &v); /* read condition */ - if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */ - luaK_goiftrue(ls->fs, &v); - return v.f; -} - - -static void gotostat (LexState *ls, int pc) { - int line = ls->linenumber; - TString *label; - int g; - if (testnext(ls, TK_GOTO)) - label = str_checkname(ls); - else { - luaX_next(ls); /* skip break */ - label = luaS_new(ls->L, "break"); - } - g = newlabelentry(ls, &ls->dyd->gt, label, line, pc); - findlabel(ls, g); /* close it if label already defined */ -} - - -/* check for repeated labels on the same block */ -static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) { - int i; - for (i = fs->bl->firstlabel; i < ll->n; i++) { - if (luaS_eqstr(label, ll->arr[i].name)) { - const char *msg = luaO_pushfstring(fs->ls->L, - "label " LUA_QS " already defined on line %d", - getstr(label), ll->arr[i].line); - semerror(fs->ls, msg); - } - } -} - - -/* skip no-op statements */ -static void skipnoopstat (LexState *ls) { - while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) - statement(ls); -} - - -static void labelstat (LexState *ls, TString *label, int line) { - /* label -> '::' NAME '::' */ - FuncState *fs = ls->fs; - Labellist *ll = &ls->dyd->label; - int l; /* index of new label being created */ - checkrepeated(fs, ll, label); /* check for repeated labels */ - checknext(ls, TK_DBCOLON); /* skip double colon */ - /* create new entry for this label */ - l = newlabelentry(ls, ll, label, line, fs->pc); - skipnoopstat(ls); /* skip other no-op statements */ - if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */ - /* assume that locals are already out of scope */ - ll->arr[l].nactvar = fs->bl->nactvar; - } - findgotos(ls, &ll->arr[l]); -} - - -static void whilestat (LexState *ls, int line) { - /* whilestat -> WHILE cond DO block END */ - FuncState *fs = ls->fs; - int whileinit; - int condexit; - BlockCnt bl; - luaX_next(ls); /* skip WHILE */ - whileinit = luaK_getlabel(fs); - condexit = cond(ls); - enterblock(fs, &bl, 1); - checknext(ls, TK_DO); - block(ls); - luaK_jumpto(fs, whileinit); - check_match(ls, TK_END, TK_WHILE, line); - leaveblock(fs); - luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ -} - - -static void repeatstat (LexState *ls, int line) { - /* repeatstat -> REPEAT block UNTIL cond */ - int condexit; - FuncState *fs = ls->fs; - int repeat_init = luaK_getlabel(fs); - BlockCnt bl1, bl2; - enterblock(fs, &bl1, 1); /* loop block */ - enterblock(fs, &bl2, 0); /* scope block */ - luaX_next(ls); /* skip REPEAT */ - statlist(ls); - check_match(ls, TK_UNTIL, TK_REPEAT, line); - condexit = cond(ls); /* read condition (inside scope block) */ - if (bl2.upval) /* upvalues? */ - luaK_patchclose(fs, condexit, bl2.nactvar); - leaveblock(fs); /* finish scope */ - luaK_patchlist(fs, condexit, repeat_init); /* close the loop */ - leaveblock(fs); /* finish loop */ -} - - -static int exp1 (LexState *ls) { - expdesc e; - int reg; - expr(ls, &e); - luaK_exp2nextreg(ls->fs, &e); - lua_assert(e.k == VNONRELOC); - reg = e.u.info; - return reg; -} - - -static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { - /* forbody -> DO block */ - BlockCnt bl; - FuncState *fs = ls->fs; - int prep, endfor; - adjustlocalvars(ls, 3); /* control variables */ - checknext(ls, TK_DO); - prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs); - enterblock(fs, &bl, 0); /* scope for declared variables */ - adjustlocalvars(ls, nvars); - luaK_reserveregs(fs, nvars); - block(ls); - leaveblock(fs); /* end of scope for declared variables */ - luaK_patchtohere(fs, prep); - if (isnum) /* numeric for? */ - endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP); - else { /* generic for */ - luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars); - luaK_fixline(fs, line); - endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP); - } - luaK_patchlist(fs, endfor, prep + 1); - luaK_fixline(fs, line); -} - - -static void fornum (LexState *ls, TString *varname, int line) { - /* fornum -> NAME = exp1,exp1[,exp1] forbody */ - FuncState *fs = ls->fs; - int base = fs->freereg; - new_localvarliteral(ls, "(for index)"); - new_localvarliteral(ls, "(for limit)"); - new_localvarliteral(ls, "(for step)"); - new_localvar(ls, varname); - checknext(ls, '='); - exp1(ls); /* initial value */ - checknext(ls, ','); - exp1(ls); /* limit */ - if (testnext(ls, ',')) - exp1(ls); /* optional step */ - else { /* default step = 1 */ - luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1)); - luaK_reserveregs(fs, 1); - } - forbody(ls, base, line, 1, 1); -} - - -static void forlist (LexState *ls, TString *indexname) { - /* forlist -> NAME {,NAME} IN explist forbody */ - FuncState *fs = ls->fs; - expdesc e; - int nvars = 4; /* gen, state, control, plus at least one declared var */ - int line; - int base = fs->freereg; - /* create control variables */ - new_localvarliteral(ls, "(for generator)"); - new_localvarliteral(ls, "(for state)"); - new_localvarliteral(ls, "(for control)"); - /* create declared variables */ - new_localvar(ls, indexname); - while (testnext(ls, ',')) { - new_localvar(ls, str_checkname(ls)); - nvars++; - } - checknext(ls, TK_IN); - line = ls->linenumber; - adjust_assign(ls, 3, explist(ls, &e), &e); - luaK_checkstack(fs, 3); /* extra space to call generator */ - forbody(ls, base, line, nvars - 3, 0); -} - - -static void forstat (LexState *ls, int line) { - /* forstat -> FOR (fornum | forlist) END */ - FuncState *fs = ls->fs; - TString *varname; - BlockCnt bl; - enterblock(fs, &bl, 1); /* scope for loop and control variables */ - luaX_next(ls); /* skip `for' */ - varname = str_checkname(ls); /* first variable name */ - switch (ls->t.token) { - case '=': fornum(ls, varname, line); break; - case ',': case TK_IN: forlist(ls, varname); break; - default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected"); - } - check_match(ls, TK_END, TK_FOR, line); - leaveblock(fs); /* loop scope (`break' jumps to this point) */ -} - - -static void test_then_block (LexState *ls, int *escapelist) { - /* test_then_block -> [IF | ELSEIF] cond THEN block */ - BlockCnt bl; - FuncState *fs = ls->fs; - expdesc v; - int jf; /* instruction to skip 'then' code (if condition is false) */ - luaX_next(ls); /* skip IF or ELSEIF */ - expr(ls, &v); /* read condition */ - checknext(ls, TK_THEN); - if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { - luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ - enterblock(fs, &bl, 0); /* must enter block before 'goto' */ - gotostat(ls, v.t); /* handle goto/break */ - skipnoopstat(ls); /* skip other no-op statements */ - if (block_follow(ls, 0)) { /* 'goto' is the entire block? */ - leaveblock(fs); - return; /* and that is it */ - } - else /* must skip over 'then' part if condition is false */ - jf = luaK_jump(fs); - } - else { /* regular case (not goto/break) */ - luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ - enterblock(fs, &bl, 0); - jf = v.f; - } - statlist(ls); /* `then' part */ - leaveblock(fs); - if (ls->t.token == TK_ELSE || - ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ - luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ - luaK_patchtohere(fs, jf); -} - - -static void ifstat (LexState *ls, int line) { - /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ - FuncState *fs = ls->fs; - int escapelist = NO_JUMP; /* exit list for finished parts */ - test_then_block(ls, &escapelist); /* IF cond THEN block */ - while (ls->t.token == TK_ELSEIF) - test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */ - if (testnext(ls, TK_ELSE)) - block(ls); /* `else' part */ - check_match(ls, TK_END, TK_IF, line); - luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ -} - - -static void localfunc (LexState *ls) { - expdesc b; - FuncState *fs = ls->fs; - new_localvar(ls, str_checkname(ls)); /* new local variable */ - adjustlocalvars(ls, 1); /* enter its scope */ - body(ls, &b, 0, ls->linenumber); /* function created in next register */ - /* debug information will only see the variable after this point! */ - getlocvar(fs, b.u.info)->startpc = fs->pc; -} - - -static void localstat (LexState *ls) { - /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */ - int nvars = 0; - int nexps; - expdesc e; - do { - new_localvar(ls, str_checkname(ls)); - nvars++; - } while (testnext(ls, ',')); - if (testnext(ls, '=')) - nexps = explist(ls, &e); - else { - e.k = VVOID; - nexps = 0; - } - adjust_assign(ls, nvars, nexps, &e); - adjustlocalvars(ls, nvars); -} - - -static int funcname (LexState *ls, expdesc *v) { - /* funcname -> NAME {fieldsel} [`:' NAME] */ - int ismethod = 0; - singlevar(ls, v); - while (ls->t.token == '.') - fieldsel(ls, v); - if (ls->t.token == ':') { - ismethod = 1; - fieldsel(ls, v); - } - return ismethod; -} - - -static void funcstat (LexState *ls, int line) { - /* funcstat -> FUNCTION funcname body */ - int ismethod; - expdesc v, b; - luaX_next(ls); /* skip FUNCTION */ - ismethod = funcname(ls, &v); - body(ls, &b, ismethod, line); - luaK_storevar(ls->fs, &v, &b); - luaK_fixline(ls->fs, line); /* definition `happens' in the first line */ -} - - -static void exprstat (LexState *ls) { - /* stat -> func | assignment */ - FuncState *fs = ls->fs; - struct LHS_assign v; - suffixedexp(ls, &v.v); - if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */ - v.prev = NULL; - assignment(ls, &v, 1); - } - else { /* stat -> func */ - check_condition(ls, v.v.k == VCALL, "syntax error"); - SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */ - } -} - - -static void retstat (LexState *ls) { - /* stat -> RETURN [explist] [';'] */ - FuncState *fs = ls->fs; - expdesc e; - int first, nret; /* registers with returned values */ - if (block_follow(ls, 1) || ls->t.token == ';') - first = nret = 0; /* return no values */ - else { - nret = explist(ls, &e); /* optional return values */ - if (hasmultret(e.k)) { - luaK_setmultret(fs, &e); - if (e.k == VCALL && nret == 1) { /* tail call? */ - SET_OPCODE(getcode(fs,&e), OP_TAILCALL); - lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); - } - first = fs->nactvar; - nret = LUA_MULTRET; /* return all values */ - } - else { - if (nret == 1) /* only one single value? */ - first = luaK_exp2anyreg(fs, &e); - else { - luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ - first = fs->nactvar; /* return all `active' values */ - lua_assert(nret == fs->freereg - first); - } - } - } - luaK_ret(fs, first, nret); - testnext(ls, ';'); /* skip optional semicolon */ -} - - -static void statement (LexState *ls) { - int line = ls->linenumber; /* may be needed for error messages */ - enterlevel(ls); - switch (ls->t.token) { - case ';': { /* stat -> ';' (empty statement) */ - luaX_next(ls); /* skip ';' */ - break; - } - case TK_IF: { /* stat -> ifstat */ - ifstat(ls, line); - break; - } - case TK_WHILE: { /* stat -> whilestat */ - whilestat(ls, line); - break; - } - case TK_DO: { /* stat -> DO block END */ - luaX_next(ls); /* skip DO */ - block(ls); - check_match(ls, TK_END, TK_DO, line); - break; - } - case TK_FOR: { /* stat -> forstat */ - forstat(ls, line); - break; - } - case TK_REPEAT: { /* stat -> repeatstat */ - repeatstat(ls, line); - break; - } - case TK_FUNCTION: { /* stat -> funcstat */ - funcstat(ls, line); - break; - } - case TK_LOCAL: { /* stat -> localstat */ - luaX_next(ls); /* skip LOCAL */ - if (testnext(ls, TK_FUNCTION)) /* local function? */ - localfunc(ls); - else - localstat(ls); - break; - } - case TK_DBCOLON: { /* stat -> label */ - luaX_next(ls); /* skip double colon */ - labelstat(ls, str_checkname(ls), line); - break; - } - case TK_RETURN: { /* stat -> retstat */ - luaX_next(ls); /* skip RETURN */ - retstat(ls); - break; - } - case TK_BREAK: /* stat -> breakstat */ - case TK_GOTO: { /* stat -> 'goto' NAME */ - gotostat(ls, luaK_jump(ls->fs)); - break; - } - default: { /* stat -> func | assignment */ - exprstat(ls); - break; - } - } - lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && - ls->fs->freereg >= ls->fs->nactvar); - ls->fs->freereg = ls->fs->nactvar; /* free registers */ - leavelevel(ls); -} - -/* }====================================================================== */ - - -/* -** compiles the main function, which is a regular vararg function with an -** upvalue named LUA_ENV -*/ -static void mainfunc (LexState *ls, FuncState *fs) { - BlockCnt bl; - expdesc v; - open_func(ls, fs, &bl); - fs->f->is_vararg = 1; /* main function is always vararg */ - init_exp(&v, VLOCAL, 0); /* create and... */ - newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */ - luaX_next(ls); /* read first token */ - statlist(ls); /* parse main body */ - check(ls, TK_EOS); - close_func(ls); -} - - -Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, - Dyndata *dyd, const char *name, int firstchar) { - LexState lexstate; - FuncState funcstate; - Closure *cl = luaF_newLclosure(L, 1); /* create main closure */ - /* anchor closure (to avoid being collected) */ - setclLvalue(L, L->top, cl); - incr_top(L); - funcstate.f = cl->l.p = luaF_newproto(L); - funcstate.f->source = luaS_new(L, name); /* create and anchor TString */ - lexstate.buff = buff; - lexstate.dyd = dyd; - dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; - luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar); - mainfunc(&lexstate, &funcstate); - lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs); - /* all scopes should be correctly finished */ - lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0); - return cl; /* it's on the stack too */ -} - |