--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/liblua/lparser.c Mon Feb 15 19:49:20 2010 +0000
@@ -0,0 +1,1339 @@
+/*
+** $Id: lparser.c,v 2.42.1.3 2007/12/28 15:32:23 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"
+
+
+
+#define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
+
+#define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]])
+
+#define luaY_checklimit(fs,v,l,m) if ((v)>(l)) errorlimit(fs,l,m)
+
+
+/*
+** nodes for block list (list of active blocks)
+*/
+typedef struct BlockCnt {
+ struct BlockCnt *previous; /* chain */
+ int breaklist; /* list of jumps out of this loop */
+ lu_byte nactvar; /* # active locals outside the breakable structure */
+ lu_byte upval; /* true if some variable in the block is an upvalue */
+ lu_byte isbreakable; /* true if `block' is a loop */
+} BlockCnt;
+
+
+
+/*
+** prototypes for recursive non-terminal functions
+*/
+static void chunk (LexState *ls);
+static void expr (LexState *ls, expdesc *v);
+
+
+static void anchor_token (LexState *ls) {
+ 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);
+ }
+}
+
+
+static void error_expected (LexState *ls, int token) {
+ luaX_syntaxerror(ls,
+ luaO_pushfstring(ls->L, LUA_QS " expected", luaX_token2str(ls, token)));
+}
+
+
+static void errorlimit (FuncState *fs, int limit, const char *what) {
+ const char *msg = (fs->f->linedefined == 0) ?
+ luaO_pushfstring(fs->L, "main function has more than %d %s", limit, what) :
+ luaO_pushfstring(fs->L, "function at line %d has more than %d %s",
+ fs->f->linedefined, limit, what);
+ luaX_lexerror(fs->ls, msg, 0);
+}
+
+
+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,
+ LUA_QS " expected (to close " LUA_QS " 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.s.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, "too many 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++;
+}
+
+
+#define new_localvarliteral(ls,v,n) \
+ new_localvar(ls, luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char))-1), n)
+
+
+static void new_localvar (LexState *ls, TString *name, int n) {
+ FuncState *fs = ls->fs;
+ luaY_checklimit(fs, fs->nactvar+n+1, LUAI_MAXVARS, "local variables");
+ fs->actvar[fs->nactvar+n] = cast(unsigned short, registerlocalvar(ls, name));
+}
+
+
+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 (LexState *ls, int tolevel) {
+ FuncState *fs = ls->fs;
+ while (fs->nactvar > tolevel)
+ getlocvar(fs, --fs->nactvar).endpc = fs->pc;
+}
+
+
+static int indexupvalue (FuncState *fs, TString *name, expdesc *v) {
+ int i;
+ Proto *f = fs->f;
+ int oldsize = f->sizeupvalues;
+ for (i=0; i<f->nups; i++) {
+ if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) {
+ lua_assert(f->upvalues[i] == name);
+ return i;
+ }
+ }
+ /* new one */
+ luaY_checklimit(fs, f->nups + 1, LUAI_MAXUPVALUES, "upvalues");
+ luaM_growvector(fs->L, f->upvalues, f->nups, f->sizeupvalues,
+ TString *, MAX_INT, "");
+ while (oldsize < f->sizeupvalues) f->upvalues[oldsize++] = NULL;
+ f->upvalues[f->nups] = name;
+ luaC_objbarrier(fs->L, f, name);
+ lua_assert(v->k == VLOCAL || v->k == VUPVAL);
+ fs->upvalues[f->nups].k = cast_byte(v->k);
+ fs->upvalues[f->nups].info = cast_byte(v->u.s.info);
+ return f->nups++;
+}
+
+
+static int searchvar (FuncState *fs, TString *n) {
+ int i;
+ for (i=fs->nactvar-1; i >= 0; i--) {
+ if (n == getlocvar(fs, i).varname)
+ return i;
+ }
+ return -1; /* not found */
+}
+
+
+static void markupval (FuncState *fs, int level) {
+ BlockCnt *bl = fs->bl;
+ while (bl && bl->nactvar > level) bl = bl->previous;
+ if (bl) bl->upval = 1;
+}
+
+
+static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
+ if (fs == NULL) { /* no more levels? */
+ init_exp(var, VGLOBAL, NO_REG); /* default is global variable */
+ return VGLOBAL;
+ }
+ else {
+ int v = searchvar(fs, n); /* look up at current level */
+ if (v >= 0) {
+ init_exp(var, VLOCAL, v);
+ if (!base)
+ markupval(fs, v); /* local will be used as an upval */
+ return VLOCAL;
+ }
+ else { /* not found at current level; try upper one */
+ if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL)
+ return VGLOBAL;
+ var->u.s.info = indexupvalue(fs, n, var); /* else was LOCAL or UPVAL */
+ var->k = VUPVAL; /* upvalue in this level */
+ return VUPVAL;
+ }
+ }
+}
+
+
+static void singlevar (LexState *ls, expdesc *var) {
+ TString *varname = str_checkname(ls);
+ FuncState *fs = ls->fs;
+ if (singlevaraux(fs, varname, var, 1) == VGLOBAL)
+ var->u.s.info = luaK_stringK(fs, varname); /* info points to global name */
+}
+
+
+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) {
+ if (++ls->L->nCcalls > LUAI_MAXCCALLS)
+ luaX_lexerror(ls, "chunk has too many syntax levels", 0);
+}
+
+
+#define leavelevel(ls) ((ls)->L->nCcalls--)
+
+
+static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) {
+ bl->breaklist = NO_JUMP;
+ bl->isbreakable = isbreakable;
+ bl->nactvar = fs->nactvar;
+ bl->upval = 0;
+ bl->previous = fs->bl;
+ fs->bl = bl;
+ lua_assert(fs->freereg == fs->nactvar);
+}
+
+
+static void leaveblock (FuncState *fs) {
+ BlockCnt *bl = fs->bl;
+ fs->bl = bl->previous;
+ removevars(fs->ls, bl->nactvar);
+ if (bl->upval)
+ luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
+ /* a block either controls scope or breaks (never both) */
+ lua_assert(!bl->isbreakable || !bl->upval);
+ lua_assert(bl->nactvar == fs->nactvar);
+ fs->freereg = fs->nactvar; /* free registers */
+ luaK_patchtohere(fs, bl->breaklist);
+}
+
+
+static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
+ FuncState *fs = ls->fs;
+ Proto *f = fs->f;
+ int oldsize = f->sizep;
+ int i;
+ luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
+ MAXARG_Bx, "constant table overflow");
+ while (oldsize < f->sizep) f->p[oldsize++] = NULL;
+ f->p[fs->np++] = func->f;
+ luaC_objbarrier(ls->L, f, func->f);
+ init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
+ for (i=0; i<func->f->nups; i++) {
+ OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
+ luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
+ }
+}
+
+
+static void open_func (LexState *ls, FuncState *fs) {
+ lua_State *L = ls->L;
+ Proto *f = luaF_newproto(L);
+ fs->f = f;
+ fs->prev = ls->fs; /* linked list of funcstates */
+ fs->ls = ls;
+ fs->L = L;
+ ls->fs = fs;
+ fs->pc = 0;
+ fs->lasttarget = -1;
+ fs->jpc = NO_JUMP;
+ fs->freereg = 0;
+ fs->nk = 0;
+ fs->np = 0;
+ fs->nlocvars = 0;
+ fs->nactvar = 0;
+ fs->bl = NULL;
+ f->source = ls->source;
+ f->maxstacksize = 2; /* registers 0/1 are always valid */
+ fs->h = luaH_new(L, 0, 0);
+ /* anchor table of constants and prototype (to avoid being collected) */
+ sethvalue2s(L, L->top, fs->h);
+ incr_top(L);
+ setptvalue2s(L, L->top, f);
+ incr_top(L);
+}
+
+
+static void close_func (LexState *ls) {
+ lua_State *L = ls->L;
+ FuncState *fs = ls->fs;
+ Proto *f = fs->f;
+ removevars(ls, 0);
+ luaK_ret(fs, 0, 0); /* final return */
+ 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, f->nups, TString *);
+ f->sizeupvalues = f->nups;
+ lua_assert(luaG_checkcode(f));
+ lua_assert(fs->bl == NULL);
+ ls->fs = fs->prev;
+ L->top -= 2; /* remove table and prototype from the stack */
+ /* last token read was anchored in defunct function; must reanchor it */
+ if (fs) anchor_token(ls);
+}
+
+
+Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, const char *name) {
+ struct LexState lexstate;
+ struct FuncState funcstate;
+ lexstate.buff = buff;
+ luaX_setinput(L, &lexstate, z, luaS_new(L, name));
+ open_func(&lexstate, &funcstate);
+ funcstate.f->is_vararg = VARARG_ISVARARG; /* main func. is always vararg */
+ luaX_next(&lexstate); /* read first token */
+ chunk(&lexstate);
+ check(&lexstate, TK_EOS);
+ close_func(&lexstate);
+ lua_assert(funcstate.prev == NULL);
+ lua_assert(funcstate.f->nups == 0);
+ lua_assert(lexstate.fs == NULL);
+ return funcstate.f;
+}
+
+
+
+/*============================================================*/
+/* GRAMMAR RULES */
+/*============================================================*/
+
+
+static void field (LexState *ls, expdesc *v) {
+ /* field -> ['.' | ':'] NAME */
+ FuncState *fs = ls->fs;
+ expdesc key;
+ luaK_exp2anyreg(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) {
+ luaY_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.s.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.s.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.s.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.s.info, cc->na, cc->tostore);
+ }
+}
+
+
+static void listfield (LexState *ls, struct ConsControl *cc) {
+ expr(ls, &cc->v);
+ luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
+ cc->na++;
+ cc->tostore++;
+}
+
+
+static void constructor (LexState *ls, expdesc *t) {
+ /* constructor -> ?? */
+ 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 (for gc) */
+ checknext(ls, '{');
+ do {
+ lua_assert(cc.v.k == VVOID || cc.tostore > 0);
+ if (ls->t.token == '}') break;
+ closelistfield(fs, &cc);
+ switch(ls->t.token) {
+ case TK_NAME: { /* may be listfields or recfields */
+ luaX_lookahead(ls);
+ if (ls->lookahead.token != '=') /* expression? */
+ listfield(ls, &cc);
+ else
+ recfield(ls, &cc);
+ break;
+ }
+ case '[': { /* constructor_item -> recfield */
+ recfield(ls, &cc);
+ break;
+ }
+ default: { /* constructor_part -> listfield */
+ listfield(ls, &cc);
+ break;
+ }
+ }
+ } 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);
+#if defined(LUA_COMPAT_VARARG)
+ /* use `arg' as default name */
+ new_localvarliteral(ls, "arg", nparams++);
+ f->is_vararg = VARARG_HASARG | VARARG_NEEDSARG;
+#endif
+ f->is_vararg |= VARARG_ISVARARG;
+ 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 - (f->is_vararg & VARARG_HASARG));
+ luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
+}
+
+
+static void body (LexState *ls, expdesc *e, int needself, int line) {
+ /* body -> `(' parlist `)' chunk END */
+ FuncState new_fs;
+ open_func(ls, &new_fs);
+ new_fs.f->linedefined = line;
+ checknext(ls, '(');
+ if (needself) {
+ new_localvarliteral(ls, "self", 0);
+ adjustlocalvars(ls, 1);
+ }
+ parlist(ls);
+ checknext(ls, ')');
+ chunk(ls);
+ new_fs.f->lastlinedefined = ls->linenumber;
+ check_match(ls, TK_END, TK_FUNCTION, line);
+ close_func(ls);
+ pushclosure(ls, &new_fs, e);
+}
+
+
+static int explist1 (LexState *ls, expdesc *v) {
+ /* explist1 -> 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) {
+ FuncState *fs = ls->fs;
+ expdesc args;
+ int base, nparams;
+ int line = ls->linenumber;
+ switch (ls->t.token) {
+ case '(': { /* funcargs -> `(' [ explist1 ] `)' */
+ if (line != ls->lastline)
+ luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)");
+ luaX_next(ls);
+ if (ls->t.token == ')') /* arg list is empty? */
+ args.k = VVOID;
+ else {
+ explist1(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");
+ return;
+ }
+ }
+ lua_assert(f->k == VNONRELOC);
+ base = f->u.s.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 prefixexp (LexState *ls, expdesc *v) {
+ /* prefixexp -> 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");
+ return;
+ }
+ }
+}
+
+
+static void primaryexp (LexState *ls, expdesc *v) {
+ /* primaryexp ->
+ prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
+ FuncState *fs = ls->fs;
+ prefixexp(ls, v);
+ for (;;) {
+ switch (ls->t.token) {
+ case '.': { /* field */
+ field(ls, v);
+ break;
+ }
+ case '[': { /* `[' exp1 `]' */
+ expdesc key;
+ luaK_exp2anyreg(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);
+ break;
+ }
+ case '(': case TK_STRING: case '{': { /* funcargs */
+ luaK_exp2nextreg(fs, v);
+ funcargs(ls, v);
+ break;
+ }
+ default: return;
+ }
+ }
+}
+
+
+static void simpleexp (LexState *ls, expdesc *v) {
+ /* simpleexp -> NUMBER | STRING | NIL | true | false | ... |
+ constructor | FUNCTION body | primaryexp */
+ 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");
+ fs->f->is_vararg &= ~VARARG_NEEDSARG; /* don't need 'arg' */
+ 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: {
+ primaryexp(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}, /* power and concat (right associative) */
+ {3, 3}, {3, 3}, /* equality and inequality */
+ {3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */
+ {2, 2}, {1, 1} /* logical (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, unsigned int limit) {
+ BinOpr op;
+ UnOpr uop;
+ enterlevel(ls);
+ uop = getunopr(ls->t.token);
+ if (uop != OPR_NOUNOPR) {
+ luaX_next(ls);
+ subexpr(ls, v, UNARY_PRIORITY);
+ luaK_prefix(ls->fs, uop, v);
+ }
+ 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;
+ 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);
+ 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 int block_follow (int token) {
+ switch (token) {
+ case TK_ELSE: case TK_ELSEIF: case TK_END:
+ case TK_UNTIL: case TK_EOS:
+ return 1;
+ default: return 0;
+ }
+}
+
+
+static void block (LexState *ls) {
+ /* block -> chunk */
+ FuncState *fs = ls->fs;
+ BlockCnt bl;
+ enterblock(fs, &bl, 0);
+ chunk(ls);
+ lua_assert(bl.breaklist == NO_JUMP);
+ 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 a local variable, the local variable
+** is needed in a previous assignment (to a table). If so, save original
+** 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) {
+ if (lh->v.k == VINDEXED) {
+ if (lh->v.u.s.info == v->u.s.info) { /* conflict? */
+ conflict = 1;
+ lh->v.u.s.info = extra; /* previous assignment will use safe copy */
+ }
+ if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */
+ conflict = 1;
+ lh->v.u.s.aux = extra; /* previous assignment will use safe copy */
+ }
+ }
+ }
+ if (conflict) {
+ luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.s.info, 0); /* make copy */
+ luaK_reserveregs(fs, 1);
+ }
+}
+
+
+static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
+ expdesc e;
+ check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
+ "syntax error");
+ if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
+ struct LHS_assign nv;
+ nv.prev = lh;
+ primaryexp(ls, &nv.v);
+ if (nv.v.k == VLOCAL)
+ check_conflict(ls, lh, &nv.v);
+ luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
+ "variables in assignment");
+ assignment(ls, &nv, nvars+1);
+ }
+ else { /* assignment -> `=' explist1 */
+ int nexps;
+ checknext(ls, '=');
+ nexps = explist1(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 breakstat (LexState *ls) {
+ FuncState *fs = ls->fs;
+ BlockCnt *bl = fs->bl;
+ int upval = 0;
+ while (bl && !bl->isbreakable) {
+ upval |= bl->upval;
+ bl = bl->previous;
+ }
+ if (!bl)
+ luaX_syntaxerror(ls, "no loop to break");
+ if (upval)
+ luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
+ luaK_concat(fs, &bl->breaklist, luaK_jump(fs));
+}
+
+
+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_patchlist(fs, luaK_jump(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 */
+ chunk(ls);
+ check_match(ls, TK_UNTIL, TK_REPEAT, line);
+ condexit = cond(ls); /* read condition (inside scope block) */
+ if (!bl2.upval) { /* no upvalues? */
+ leaveblock(fs); /* finish scope */
+ luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */
+ }
+ else { /* complete semantics when there are upvalues */
+ breakstat(ls); /* if condition then break */
+ luaK_patchtohere(ls->fs, condexit); /* else... */
+ leaveblock(fs); /* finish scope... */
+ luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */
+ }
+ leaveblock(fs); /* finish loop */
+}
+
+
+static int exp1 (LexState *ls) {
+ expdesc e;
+ int k;
+ expr(ls, &e);
+ k = e.k;
+ luaK_exp2nextreg(ls->fs, &e);
+ return k;
+}
+
+
+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);
+ endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
+ luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars);
+ luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
+ luaK_patchlist(fs, (isnum ? endfor : luaK_jump(fs)), prep + 1);
+}
+
+
+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)", 0);
+ new_localvarliteral(ls, "(for limit)", 1);
+ new_localvarliteral(ls, "(for step)", 2);
+ new_localvar(ls, varname, 3);
+ checknext(ls, '=');
+ exp1(ls); /* initial value */
+ checknext(ls, ',');
+ exp1(ls); /* limit */
+ if (testnext(ls, ','))
+ exp1(ls); /* optional step */
+ else { /* default step = 1 */
+ luaK_codeABx(fs, OP_LOADK, 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 explist1 forbody */
+ FuncState *fs = ls->fs;
+ expdesc e;
+ int nvars = 0;
+ int line;
+ int base = fs->freereg;
+ /* create control variables */
+ new_localvarliteral(ls, "(for generator)", nvars++);
+ new_localvarliteral(ls, "(for state)", nvars++);
+ new_localvarliteral(ls, "(for control)", nvars++);
+ /* create declared variables */
+ new_localvar(ls, indexname, nvars++);
+ while (testnext(ls, ','))
+ new_localvar(ls, str_checkname(ls), nvars++);
+ checknext(ls, TK_IN);
+ line = ls->linenumber;
+ adjust_assign(ls, 3, explist1(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 int test_then_block (LexState *ls) {
+ /* test_then_block -> [IF | ELSEIF] cond THEN block */
+ int condexit;
+ luaX_next(ls); /* skip IF or ELSEIF */
+ condexit = cond(ls);
+ checknext(ls, TK_THEN);
+ block(ls); /* `then' part */
+ return condexit;
+}
+
+
+static void ifstat (LexState *ls, int line) {
+ /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
+ FuncState *fs = ls->fs;
+ int flist;
+ int escapelist = NO_JUMP;
+ flist = test_then_block(ls); /* IF cond THEN block */
+ while (ls->t.token == TK_ELSEIF) {
+ luaK_concat(fs, &escapelist, luaK_jump(fs));
+ luaK_patchtohere(fs, flist);
+ flist = test_then_block(ls); /* ELSEIF cond THEN block */
+ }
+ if (ls->t.token == TK_ELSE) {
+ luaK_concat(fs, &escapelist, luaK_jump(fs));
+ luaK_patchtohere(fs, flist);
+ luaX_next(ls); /* skip ELSE (after patch, for correct line info) */
+ block(ls); /* `else' part */
+ }
+ else
+ luaK_concat(fs, &escapelist, flist);
+ luaK_patchtohere(fs, escapelist);
+ check_match(ls, TK_END, TK_IF, line);
+}
+
+
+static void localfunc (LexState *ls) {
+ expdesc v, b;
+ FuncState *fs = ls->fs;
+ new_localvar(ls, str_checkname(ls), 0);
+ init_exp(&v, VLOCAL, fs->freereg);
+ luaK_reserveregs(fs, 1);
+ adjustlocalvars(ls, 1);
+ body(ls, &b, 0, ls->linenumber);
+ luaK_storevar(fs, &v, &b);
+ /* debug information will only see the variable after this point! */
+ getlocvar(fs, fs->nactvar - 1).startpc = fs->pc;
+}
+
+
+static void localstat (LexState *ls) {
+ /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
+ int nvars = 0;
+ int nexps;
+ expdesc e;
+ do {
+ new_localvar(ls, str_checkname(ls), nvars++);
+ } while (testnext(ls, ','));
+ if (testnext(ls, '='))
+ nexps = explist1(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 {field} [`:' NAME] */
+ int needself = 0;
+ singlevar(ls, v);
+ while (ls->t.token == '.')
+ field(ls, v);
+ if (ls->t.token == ':') {
+ needself = 1;
+ field(ls, v);
+ }
+ return needself;
+}
+
+
+static void funcstat (LexState *ls, int line) {
+ /* funcstat -> FUNCTION funcname body */
+ int needself;
+ expdesc v, b;
+ luaX_next(ls); /* skip FUNCTION */
+ needself = funcname(ls, &v);
+ body(ls, &b, needself, 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;
+ primaryexp(ls, &v.v);
+ if (v.v.k == VCALL) /* stat -> func */
+ SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
+ else { /* stat -> assignment */
+ v.prev = NULL;
+ assignment(ls, &v, 1);
+ }
+}
+
+
+static void retstat (LexState *ls) {
+ /* stat -> RETURN explist */
+ FuncState *fs = ls->fs;
+ expdesc e;
+ int first, nret; /* registers with returned values */
+ luaX_next(ls); /* skip RETURN */
+ if (block_follow(ls->t.token) || ls->t.token == ';')
+ first = nret = 0; /* return no values */
+ else {
+ nret = explist1(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);
+}
+
+
+static int statement (LexState *ls) {
+ int line = ls->linenumber; /* may be needed for error messages */
+ switch (ls->t.token) {
+ case TK_IF: { /* stat -> ifstat */
+ ifstat(ls, line);
+ return 0;
+ }
+ case TK_WHILE: { /* stat -> whilestat */
+ whilestat(ls, line);
+ return 0;
+ }
+ case TK_DO: { /* stat -> DO block END */
+ luaX_next(ls); /* skip DO */
+ block(ls);
+ check_match(ls, TK_END, TK_DO, line);
+ return 0;
+ }
+ case TK_FOR: { /* stat -> forstat */
+ forstat(ls, line);
+ return 0;
+ }
+ case TK_REPEAT: { /* stat -> repeatstat */
+ repeatstat(ls, line);
+ return 0;
+ }
+ case TK_FUNCTION: {
+ funcstat(ls, line); /* stat -> funcstat */
+ return 0;
+ }
+ case TK_LOCAL: { /* stat -> localstat */
+ luaX_next(ls); /* skip LOCAL */
+ if (testnext(ls, TK_FUNCTION)) /* local function? */
+ localfunc(ls);
+ else
+ localstat(ls);
+ return 0;
+ }
+ case TK_RETURN: { /* stat -> retstat */
+ retstat(ls);
+ return 1; /* must be last statement */
+ }
+ case TK_BREAK: { /* stat -> breakstat */
+ luaX_next(ls); /* skip BREAK */
+ breakstat(ls);
+ return 1; /* must be last statement */
+ }
+ default: {
+ exprstat(ls);
+ return 0; /* to avoid warnings */
+ }
+ }
+}
+
+
+static void chunk (LexState *ls) {
+ /* chunk -> { stat [`;'] } */
+ int islast = 0;
+ enterlevel(ls);
+ while (!islast && !block_follow(ls->t.token)) {
+ islast = statement(ls);
+ testnext(ls, ';');
+ 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);
+}
+
+/* }====================================================================== */