diff options
Diffstat (limited to 'lua/lparser.c')
| -rw-r--r-- | lua/lparser.c | 963 |
1 files changed, 622 insertions, 341 deletions
diff --git a/lua/lparser.c b/lua/lparser.c index 1e2a9a8..4d68936 100644 --- a/lua/lparser.c +++ b/lua/lparser.c @@ -1,5 +1,5 @@ /* -** $Id: lparser.c,v 2.42.1.3 2007/12/28 15:32:23 roberto Exp $ +** $Id: lparser.c,v 2.124 2011/12/02 13:23:56 roberto Exp $ ** Lua Parser ** See Copyright Notice in lua.h */ @@ -27,11 +27,13 @@ -#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) +/* maximum number of local variables per function (must be smaller + than 250, due to the bytecode format) */ +#define MAXVARS 200 + -#define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]]) +#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) -#define luaY_checklimit(fs,v,l,m) if ((v)>(l)) errorlimit(fs,l,m) /* @@ -39,10 +41,11 @@ */ 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 */ + 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 isbreakable; /* true if `block' is a loop */ + lu_byte isloop; /* true if `block' is a loop */ } BlockCnt; @@ -50,11 +53,13 @@ typedef struct BlockCnt { /* ** prototypes for recursive non-terminal functions */ -static void chunk (LexState *ls); +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); @@ -62,18 +67,34 @@ static void anchor_token (LexState *ls) { } -static void error_expected (LexState *ls, int token) { +/* 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, LUA_QS " expected", luaX_token2str(ls, token))); + luaO_pushfstring(ls->L, "%s 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 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); } @@ -91,6 +112,7 @@ static void check (LexState *ls, int c) { error_expected(ls, c); } + static void checknext (LexState *ls, int c) { check(ls, c); luaX_next(ls); @@ -107,7 +129,7 @@ static void check_match (LexState *ls, int what, int who, int where) { error_expected(ls, what); else { luaX_syntaxerror(ls, luaO_pushfstring(ls->L, - LUA_QS " expected (to close " LUA_QS " at line %d)", + "%s expected (to close %s at line %d)", luaX_token2str(ls, what), luaX_token2str(ls, who), where)); } } @@ -126,7 +148,7 @@ static TString *str_checkname (LexState *ls) { static void init_exp (expdesc *e, expkind k, int i) { e->f = e->t = NO_JUMP; e->k = k; - e->u.s.info = i; + e->u.info = i; } @@ -135,7 +157,7 @@ static void codestring (LexState *ls, expdesc *e, TString *s) { } -static void checkname(LexState *ls, expdesc *e) { +static void checkname (LexState *ls, expdesc *e) { codestring(ls, e, str_checkname(ls)); } @@ -145,7 +167,7 @@ static int registerlocalvar (LexState *ls, TString *varname) { 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"); + 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); @@ -153,14 +175,30 @@ static int registerlocalvar (LexState *ls, TString *varname) { } -#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) { + 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_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 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]; } @@ -168,77 +206,88 @@ 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; + getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc; } } -static void removevars (LexState *ls, int tolevel) { - FuncState *fs = ls->fs; +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; + getlocvar(fs, --fs->nactvar)->endpc = fs->pc; } -static int indexupvalue (FuncState *fs, TString *name, expdesc *v) { +static int searchupvalue (FuncState *fs, TString *name) { int i; + Upvaldesc *up = fs->f->upvalues; + for (i = 0; i < fs->nups; i++) { + if (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; - 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++; + 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=fs->nactvar-1; i >= 0; i--) { - if (n == getlocvar(fs, i).varname) + if (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 && bl->nactvar > level) bl = bl->previous; - if (bl) bl->upval = 1; + 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? */ - init_exp(var, VGLOBAL, NO_REG); /* default is global variable */ - return VGLOBAL; - } + if (fs == NULL) /* no more levels? */ + return VVOID; /* default is global */ else { - int v = searchvar(fs, n); /* look up at current level */ - if (v >= 0) { - init_exp(var, VLOCAL, v); + 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 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 */ + 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; } } @@ -248,8 +297,13 @@ static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { 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 */ + 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] */ + } } @@ -274,18 +328,118 @@ static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { static void enterlevel (LexState *ls) { - if (++ls->L->nCcalls > LUAI_MAXCCALLS) - luaX_lexerror(ls, "chunk has too many syntax levels", 0); + lua_State *L = ls->L; + ++L->nCcalls; + checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels"); } #define leavelevel(ls) ((ls)->L->nCcalls--) -static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) { - bl->breaklist = NO_JUMP; - bl->isbreakable = isbreakable; +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(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 (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 (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; @@ -293,63 +447,100 @@ static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) { } +/* +** 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 = (gt->name->tsv.reserved > 0) + ? "<%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->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); + removevars(fs, bl->nactvar); lua_assert(bl->nactvar == fs->nactvar); fs->freereg = fs->nactvar; /* free registers */ - luaK_patchtohere(fs, bl->breaklist); + 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 */ } -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); +/* +** adds prototype being created into its parent list of prototypes +** and codes instruction to create new closure +*/ +static void codeclosure (LexState *ls, Proto *clp, expdesc *v) { + FuncState *fs = ls->fs->prev; + Proto *f = fs->f; /* prototype of function creating new closure */ + if (fs->np >= f->sizep) { + int oldsize = f->sizep; + luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *, + MAXARG_Bx, "functions"); + while (oldsize < f->sizep) f->p[oldsize++] = NULL; } + f->p[fs->np++] = clp; + luaC_objbarrier(ls->L, f, clp); + init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1)); + luaK_exp2nextreg(fs, v); /* fix it at stack top (for GC) */ } -static void open_func (LexState *ls, FuncState *fs) { +static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { lua_State *L = ls->L; - Proto *f = luaF_newproto(L); - fs->f = f; + Proto *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->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 = luaF_newproto(L); + fs->f = f; 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); + /* anchor prototype (to avoid being collected) */ setptvalue2s(L, L->top, f); incr_top(L); + 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); } @@ -357,8 +548,8 @@ 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 */ + 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); @@ -369,32 +560,28 @@ static void close_func (LexState *ls) { 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)); + luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); + f->sizeupvalues = fs->nups; 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); + /* last token read was anchored in defunct function; must re-anchor it */ + anchor_token(ls); + L->top--; /* pop table of constants */ + luaC_checkGC(L); + L->top--; /* pop prototype (after possible collection) */ } -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; +/* +** opens the main function, which is a regular vararg function with an +** upvalue named LUA_ENV +*/ +static void open_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); + newupvalue(fs, ls->envn, &v); /* create environment upvalue */ } @@ -404,11 +591,39 @@ Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, const char *name) { /*============================================================*/ -static void field (LexState *ls, expdesc *v) { - /* field -> ['.' | ':'] NAME */ +/* +** 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_exp2anyreg(fs, v); + luaK_exp2anyregup(fs, v); luaX_next(ls); /* skip the dot or colon */ checkname(ls, &key); luaK_indexed(fs, v, &key); @@ -447,7 +662,7 @@ static void recfield (LexState *ls, struct ConsControl *cc) { expdesc key, val; int rkkey; if (ls->t.token == TK_NAME) { - luaY_checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); + checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); checkname(ls, &key); } else /* ls->t.token == '[' */ @@ -456,7 +671,7 @@ static void recfield (LexState *ls, struct ConsControl *cc) { 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)); + luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val)); fs->freereg = reg; /* free registers */ } @@ -466,7 +681,7 @@ static void closelistfield (FuncState *fs, struct ConsControl *cc) { 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 */ + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ cc->tostore = 0; /* no more items pending */ } } @@ -476,27 +691,51 @@ 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); + 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.s.info, cc->na, cc->tostore); + 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); - luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); + 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 -> ?? */ + /* constructor -> '{' [ field { sep field } [sep] ] '}' + sep -> ',' | ';' */ FuncState *fs = ls->fs; int line = ls->linenumber; int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); @@ -505,30 +744,13 @@ static void constructor (LexState *ls, expdesc *t) { 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) */ + 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); - 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; - } - } + field(ls, &cc); } while (testnext(ls, ',') || testnext(ls, ';')); check_match(ls, '}', '{', line); lastlistfield(fs, &cc); @@ -550,17 +772,13 @@ static void parlist (LexState *ls) { do { switch (ls->t.token) { case TK_NAME: { /* param -> NAME */ - new_localvar(ls, str_checkname(ls), nparams++); + 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; + f->is_vararg = 1; break; } default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected"); @@ -568,33 +786,34 @@ static void parlist (LexState *ls) { } while (!f->is_vararg && testnext(ls, ',')); } adjustlocalvars(ls, nparams); - f->numparams = cast_byte(fs->nactvar - (f->is_vararg & VARARG_HASARG)); + f->numparams = cast_byte(fs->nactvar); luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ } -static void body (LexState *ls, expdesc *e, int needself, int line) { - /* body -> `(' parlist `)' chunk END */ +static void body (LexState *ls, expdesc *e, int ismethod, int line) { + /* body -> `(' parlist `)' block END */ FuncState new_fs; - open_func(ls, &new_fs); + BlockCnt bl; + open_func(ls, &new_fs, &bl); new_fs.f->linedefined = line; checknext(ls, '('); - if (needself) { - new_localvarliteral(ls, "self", 0); + if (ismethod) { + new_localvarliteral(ls, "self"); /* create 'self' parameter */ adjustlocalvars(ls, 1); } parlist(ls); checknext(ls, ')'); - chunk(ls); + statlist(ls); new_fs.f->lastlinedefined = ls->linenumber; check_match(ls, TK_END, TK_FUNCTION, line); + codeclosure(ls, new_fs.f, e); close_func(ls); - pushclosure(ls, &new_fs, e); } -static int explist1 (LexState *ls, expdesc *v) { - /* explist1 -> expr { `,' expr } */ +static int explist (LexState *ls, expdesc *v) { + /* explist -> expr { `,' expr } */ int n = 1; /* at least one expression */ expr(ls, v); while (testnext(ls, ',')) { @@ -606,20 +825,17 @@ static int explist1 (LexState *ls, expdesc *v) { } -static void funcargs (LexState *ls, expdesc *f) { +static void funcargs (LexState *ls, expdesc *f, int line) { 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)"); + case '(': { /* funcargs -> `(' [ explist ] `)' */ luaX_next(ls); if (ls->t.token == ')') /* arg list is empty? */ args.k = VVOID; else { - explist1(ls, &args); + explist(ls, &args); luaK_setmultret(fs, &args); } check_match(ls, ')', '(', line); @@ -636,11 +852,10 @@ static void funcargs (LexState *ls, expdesc *f) { } default: { luaX_syntaxerror(ls, "function arguments expected"); - return; } } lua_assert(f->k == VNONRELOC); - base = f->u.s.info; /* base register for call */ + base = f->u.info; /* base register for call */ if (hasmultret(args.k)) nparams = LUA_MULTRET; /* open call */ else { @@ -681,7 +896,6 @@ static void prefixexp (LexState *ls, expdesc *v) { } default: { luaX_syntaxerror(ls, "unexpected symbol"); - return; } } } @@ -691,16 +905,17 @@ static void primaryexp (LexState *ls, expdesc *v) { /* primaryexp -> prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */ FuncState *fs = ls->fs; + int line = ls->linenumber; prefixexp(ls, v); for (;;) { switch (ls->t.token) { - case '.': { /* field */ - field(ls, v); + case '.': { /* fieldsel */ + fieldsel(ls, v); break; } case '[': { /* `[' exp1 `]' */ expdesc key; - luaK_exp2anyreg(fs, v); + luaK_exp2anyregup(fs, v); yindex(ls, &key); luaK_indexed(fs, v, &key); break; @@ -710,12 +925,12 @@ static void primaryexp (LexState *ls, expdesc *v) { luaX_next(ls); checkname(ls, &key); luaK_self(fs, v, &key); - funcargs(ls, v); + funcargs(ls, v, line); break; } case '(': case TK_STRING: case '{': { /* funcargs */ luaK_exp2nextreg(fs, v); - funcargs(ls, v); + funcargs(ls, v, line); break; } default: return; @@ -725,7 +940,7 @@ static void primaryexp (LexState *ls, expdesc *v) { static void simpleexp (LexState *ls, expdesc *v) { - /* simpleexp -> NUMBER | STRING | NIL | true | false | ... | + /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... | constructor | FUNCTION body | primaryexp */ switch (ls->t.token) { case TK_NUMBER: { @@ -753,7 +968,6 @@ static void simpleexp (LexState *ls, expdesc *v) { 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; } @@ -811,11 +1025,11 @@ 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) */ + {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 */ @@ -825,15 +1039,16 @@ static const struct { ** 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) { +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); + luaK_prefix(ls->fs, uop, v, line); } else simpleexp(ls, v); /* expand while operators have priorities higher than `limit' */ @@ -841,11 +1056,12 @@ static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) { 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); + luaK_posfix(ls->fs, op, v, &v2, line); op = nextop; } leavelevel(ls); @@ -868,23 +1084,12 @@ static void expr (LexState *ls, expdesc *v) { */ -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 */ + /* block -> statlist */ FuncState *fs = ls->fs; BlockCnt bl; enterblock(fs, &bl, 0); - chunk(ls); - lua_assert(bl.breaklist == NO_JUMP); + statlist(ls); leaveblock(fs); } @@ -900,29 +1105,34 @@ struct LHS_assign { /* -** 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. +** 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) { - if (lh->v.k == VINDEXED) { - if (lh->v.u.s.info == v->u.s.info) { /* conflict? */ + 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.s.info = extra; /* previous assignment will use safe copy */ + lh->v.u.ind.vt = VLOCAL; + lh->v.u.ind.t = extra; /* previous assignment will use safe copy */ } - if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */ + /* 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.s.aux = extra; /* previous assignment will use safe copy */ + lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */ } } } if (conflict) { - luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.s.info, 0); /* make copy */ + /* 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); } } @@ -930,22 +1140,21 @@ static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { 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"); + check_condition(ls, vkisvar(lh->v.k), "syntax error"); if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */ struct LHS_assign nv; nv.prev = lh; primaryexp(ls, &nv.v); - if (nv.v.k == VLOCAL) + if (nv.v.k != VINDEXED) check_conflict(ls, lh, &nv.v); - luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls, - "variables in assignment"); + checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS, + "C levels"); assignment(ls, &nv, nvars+1); } - else { /* assignment -> `=' explist1 */ + else { /* assignment -> `=' explist */ int nexps; checknext(ls, '='); - nexps = explist1(ls, &e); + nexps = explist(ls, &e); if (nexps != nvars) { adjust_assign(ls, nvars, nexps, &e); if (nexps > nvars) @@ -972,19 +1181,52 @@ static int cond (LexState *ls) { } -static void breakstat (LexState *ls) { +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 (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); + } + } +} + + +static void labelstat (LexState *ls, TString *label, int line) { + /* label -> '::' NAME '::' */ FuncState *fs = ls->fs; - BlockCnt *bl = fs->bl; - int upval = 0; - while (bl && !bl->isbreakable) { - upval |= bl->upval; - bl = bl->previous; + 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); + /* skip other no-op statements */ + while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) + statement(ls); + 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; } - 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)); + findgotos(ls, &ll->arr[l]); } @@ -1000,7 +1242,7 @@ static void whilestat (LexState *ls, int line) { enterblock(fs, &bl, 1); checknext(ls, TK_DO); block(ls); - luaK_patchlist(fs, luaK_jump(fs), whileinit); + luaK_jumpto(fs, whileinit); check_match(ls, TK_END, TK_WHILE, line); leaveblock(fs); luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ @@ -1016,30 +1258,25 @@ static void repeatstat (LexState *ls, int line) { enterblock(fs, &bl1, 1); /* loop block */ enterblock(fs, &bl2, 0); /* scope block */ luaX_next(ls); /* skip REPEAT */ - chunk(ls); + statlist(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 */ - } + 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 k; + int reg; expr(ls, &e); - k = e.k; luaK_exp2nextreg(ls->fs, &e); - return k; + lua_assert(e.k == VNONRELOC); + reg = e.u.info; + return reg; } @@ -1057,10 +1294,15 @@ static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { 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); + 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); } @@ -1068,10 +1310,10 @@ 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); + 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, ','); @@ -1079,7 +1321,7 @@ static void fornum (LexState *ls, TString *varname, int line) { if (testnext(ls, ',')) exp1(ls); /* optional step */ else { /* default step = 1 */ - luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1)); + luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1)); luaK_reserveregs(fs, 1); } forbody(ls, base, line, 1, 1); @@ -1087,23 +1329,25 @@ static void fornum (LexState *ls, TString *varname, int line) { static void forlist (LexState *ls, TString *indexname) { - /* forlist -> NAME {,NAME} IN explist1 forbody */ + /* forlist -> NAME {,NAME} IN explist forbody */ FuncState *fs = ls->fs; expdesc e; - int nvars = 0; + 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)", nvars++); - new_localvarliteral(ls, "(for state)", nvars++); - new_localvarliteral(ls, "(for control)", nvars++); + new_localvarliteral(ls, "(for generator)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for control)"); /* create declared variables */ - new_localvar(ls, indexname, nvars++); - while (testnext(ls, ',')) - new_localvar(ls, str_checkname(ls), nvars++); + 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, explist1(ls, &e), &e); + adjust_assign(ls, 3, explist(ls, &e), &e); luaK_checkstack(fs, 3); /* extra space to call generator */ forbody(ls, base, line, nvars - 3, 0); } @@ -1127,65 +1371,76 @@ static void forstat (LexState *ls, int line) { } -static int test_then_block (LexState *ls) { +static void test_then_block (LexState *ls, int *escapelist) { /* test_then_block -> [IF | ELSEIF] cond THEN block */ - int condexit; + 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 */ - condexit = cond(ls); + expr(ls, &v); /* read condition */ checknext(ls, TK_THEN); - block(ls); /* `then' part */ - return condexit; + 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 */ + 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 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) */ + 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 */ - } - else - luaK_concat(fs, &escapelist, flist); - luaK_patchtohere(fs, escapelist); check_match(ls, TK_END, TK_IF, line); + luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ } static void localfunc (LexState *ls) { - expdesc v, b; + expdesc 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); + 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, fs->nactvar - 1).startpc = fs->pc; + getlocvar(fs, b.u.info)->startpc = fs->pc; } static void localstat (LexState *ls) { - /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */ + /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */ int nvars = 0; int nexps; expdesc e; do { - new_localvar(ls, str_checkname(ls), nvars++); + new_localvar(ls, str_checkname(ls)); + nvars++; } while (testnext(ls, ',')); if (testnext(ls, '=')) - nexps = explist1(ls, &e); + nexps = explist(ls, &e); else { e.k = VVOID; nexps = 0; @@ -1196,26 +1451,26 @@ static void localstat (LexState *ls) { static int funcname (LexState *ls, expdesc *v) { - /* funcname -> NAME {field} [`:' NAME] */ - int needself = 0; + /* funcname -> NAME {fieldsel} [`:' NAME] */ + int ismethod = 0; singlevar(ls, v); while (ls->t.token == '.') - field(ls, v); + fieldsel(ls, v); if (ls->t.token == ':') { - needself = 1; - field(ls, v); + ismethod = 1; + fieldsel(ls, v); } - return needself; + return ismethod; } static void funcstat (LexState *ls, int line) { /* funcstat -> FUNCTION funcname body */ - int needself; + int ismethod; expdesc v, b; luaX_next(ls); /* skip FUNCTION */ - needself = funcname(ls, &v); - body(ls, &b, needself, line); + 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 */ } @@ -1236,15 +1491,14 @@ static void exprstat (LexState *ls) { static void retstat (LexState *ls) { - /* stat -> RETURN explist */ + /* 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 == ';') + if (block_follow(ls, 1) || ls->t.token == ';') first = nret = 0; /* return no values */ else { - nret = explist1(ls, &e); /* optional return values */ + nret = explist(ls, &e); /* optional return values */ if (hasmultret(e.k)) { luaK_setmultret(fs, &e); if (e.k == VCALL && nret == 1) { /* tail call? */ @@ -1265,37 +1519,43 @@ static void retstat (LexState *ls) { } } luaK_ret(fs, first, nret); + testnext(ls, ';'); /* skip optional semicolon */ } -static int statement (LexState *ls) { +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); - return 0; + break; } case TK_WHILE: { /* stat -> whilestat */ whilestat(ls, line); - return 0; + break; } case TK_DO: { /* stat -> DO block END */ luaX_next(ls); /* skip DO */ block(ls); check_match(ls, TK_END, TK_DO, line); - return 0; + break; } case TK_FOR: { /* stat -> forstat */ forstat(ls, line); - return 0; + break; } case TK_REPEAT: { /* stat -> repeatstat */ repeatstat(ls, line); - return 0; + break; } - case TK_FUNCTION: { - funcstat(ls, line); /* stat -> funcstat */ - return 0; + case TK_FUNCTION: { /* stat -> funcstat */ + funcstat(ls, line); + break; } case TK_LOCAL: { /* stat -> localstat */ luaX_next(ls); /* skip LOCAL */ @@ -1303,37 +1563,58 @@ static int statement (LexState *ls) { localfunc(ls); else localstat(ls); - return 0; + 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); - return 1; /* must be last statement */ + break; } - case TK_BREAK: { /* stat -> breakstat */ - luaX_next(ls); /* skip BREAK */ - breakstat(ls); - return 1; /* must be last statement */ + case TK_BREAK: /* stat -> breakstat */ + case TK_GOTO: { /* stat -> 'goto' NAME */ + gotostat(ls, luaK_jump(ls->fs)); + break; } - default: { + default: { /* stat -> func | assignment */ exprstat(ls); - return 0; /* to avoid warnings */ + 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); } +/* }====================================================================== */ -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); + +Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar) { + LexState lexstate; + FuncState funcstate; + BlockCnt bl; + TString *tname = luaS_new(L, name); + setsvalue2s(L, L->top, tname); /* push name to protect it */ + incr_top(L); + lexstate.buff = buff; + lexstate.dyd = dyd; + dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; + luaX_setinput(L, &lexstate, z, tname, firstchar); + open_mainfunc(&lexstate, &funcstate, &bl); + luaX_next(&lexstate); /* read first token */ + statlist(&lexstate); /* main body */ + check(&lexstate, TK_EOS); + close_func(&lexstate); + L->top--; /* pop name */ + 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 funcstate.f; } -/* }====================================================================== */ |