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| author | Li Jin <dragon-fly@qq.com> | 2020-06-22 16:50:40 +0800 |
|---|---|---|
| committer | Li Jin <dragon-fly@qq.com> | 2020-06-22 16:50:40 +0800 |
| commit | cd2b60b101a398cb9356d746364e70eaed1860f1 (patch) | |
| tree | a1fe71b76faabc4883f16905a94164ce5c23e692 /src/lua-5.3/lparser.c | |
| parent | 88c1052e700f38cf3d8ad82d469da4c487760b7e (diff) | |
| download | yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.tar.gz yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.tar.bz2 yuescript-cd2b60b101a398cb9356d746364e70eaed1860f1.zip | |
add support for local variable declared with attribute 'close' and 'const' for Lua 5.4.
Diffstat (limited to 'src/lua-5.3/lparser.c')
| -rw-r--r-- | src/lua-5.3/lparser.c | 1650 |
1 files changed, 0 insertions, 1650 deletions
diff --git a/src/lua-5.3/lparser.c b/src/lua-5.3/lparser.c deleted file mode 100644 index cc54de4..0000000 --- a/src/lua-5.3/lparser.c +++ /dev/null | |||
| @@ -1,1650 +0,0 @@ | |||
| 1 | /* | ||
| 2 | ** $Id: lparser.c,v 2.155.1.2 2017/04/29 18:11:40 roberto Exp $ | ||
| 3 | ** Lua Parser | ||
| 4 | ** See Copyright Notice in lua.h | ||
| 5 | */ | ||
| 6 | |||
| 7 | #define lparser_c | ||
| 8 | #define LUA_CORE | ||
| 9 | |||
| 10 | #include "lprefix.h" | ||
| 11 | |||
| 12 | |||
| 13 | #include <string.h> | ||
| 14 | |||
| 15 | #include "lua.h" | ||
| 16 | |||
| 17 | #include "lcode.h" | ||
| 18 | #include "ldebug.h" | ||
| 19 | #include "ldo.h" | ||
| 20 | #include "lfunc.h" | ||
| 21 | #include "llex.h" | ||
| 22 | #include "lmem.h" | ||
| 23 | #include "lobject.h" | ||
| 24 | #include "lopcodes.h" | ||
| 25 | #include "lparser.h" | ||
| 26 | #include "lstate.h" | ||
| 27 | #include "lstring.h" | ||
| 28 | #include "ltable.h" | ||
| 29 | |||
| 30 | |||
| 31 | |||
| 32 | /* maximum number of local variables per function (must be smaller | ||
| 33 | than 250, due to the bytecode format) */ | ||
| 34 | #define MAXVARS 200 | ||
| 35 | |||
| 36 | |||
| 37 | #define hasmultret(k) ((k) == VCALL || (k) == VVARARG) | ||
| 38 | |||
| 39 | |||
| 40 | /* because all strings are unified by the scanner, the parser | ||
| 41 | can use pointer equality for string equality */ | ||
| 42 | #define eqstr(a,b) ((a) == (b)) | ||
| 43 | |||
| 44 | |||
| 45 | /* | ||
| 46 | ** nodes for block list (list of active blocks) | ||
| 47 | */ | ||
| 48 | typedef struct BlockCnt { | ||
| 49 | struct BlockCnt *previous; /* chain */ | ||
| 50 | int firstlabel; /* index of first label in this block */ | ||
| 51 | int firstgoto; /* index of first pending goto in this block */ | ||
| 52 | lu_byte nactvar; /* # active locals outside the block */ | ||
| 53 | lu_byte upval; /* true if some variable in the block is an upvalue */ | ||
| 54 | lu_byte isloop; /* true if 'block' is a loop */ | ||
| 55 | } BlockCnt; | ||
| 56 | |||
| 57 | |||
| 58 | |||
| 59 | /* | ||
| 60 | ** prototypes for recursive non-terminal functions | ||
| 61 | */ | ||
| 62 | static void statement (LexState *ls); | ||
| 63 | static void expr (LexState *ls, expdesc *v); | ||
| 64 | |||
| 65 | |||
| 66 | /* semantic error */ | ||
| 67 | static l_noret semerror (LexState *ls, const char *msg) { | ||
| 68 | ls->t.token = 0; /* remove "near <token>" from final message */ | ||
| 69 | luaX_syntaxerror(ls, msg); | ||
| 70 | } | ||
| 71 | |||
| 72 | |||
| 73 | static l_noret error_expected (LexState *ls, int token) { | ||
| 74 | luaX_syntaxerror(ls, | ||
| 75 | luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token))); | ||
| 76 | } | ||
| 77 | |||
| 78 | |||
| 79 | static l_noret errorlimit (FuncState *fs, int limit, const char *what) { | ||
| 80 | lua_State *L = fs->ls->L; | ||
| 81 | const char *msg; | ||
| 82 | int line = fs->f->linedefined; | ||
| 83 | const char *where = (line == 0) | ||
| 84 | ? "main function" | ||
| 85 | : luaO_pushfstring(L, "function at line %d", line); | ||
| 86 | msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s", | ||
| 87 | what, limit, where); | ||
| 88 | luaX_syntaxerror(fs->ls, msg); | ||
| 89 | } | ||
| 90 | |||
| 91 | |||
| 92 | static void checklimit (FuncState *fs, int v, int l, const char *what) { | ||
| 93 | if (v > l) errorlimit(fs, l, what); | ||
| 94 | } | ||
| 95 | |||
| 96 | |||
| 97 | static int testnext (LexState *ls, int c) { | ||
| 98 | if (ls->t.token == c) { | ||
| 99 | luaX_next(ls); | ||
| 100 | return 1; | ||
| 101 | } | ||
| 102 | else return 0; | ||
| 103 | } | ||
| 104 | |||
| 105 | |||
| 106 | static void check (LexState *ls, int c) { | ||
| 107 | if (ls->t.token != c) | ||
| 108 | error_expected(ls, c); | ||
| 109 | } | ||
| 110 | |||
| 111 | |||
| 112 | static void checknext (LexState *ls, int c) { | ||
| 113 | check(ls, c); | ||
| 114 | luaX_next(ls); | ||
| 115 | } | ||
| 116 | |||
| 117 | |||
| 118 | #define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } | ||
| 119 | |||
| 120 | |||
| 121 | |||
| 122 | static void check_match (LexState *ls, int what, int who, int where) { | ||
| 123 | if (!testnext(ls, what)) { | ||
| 124 | if (where == ls->linenumber) | ||
| 125 | error_expected(ls, what); | ||
| 126 | else { | ||
| 127 | luaX_syntaxerror(ls, luaO_pushfstring(ls->L, | ||
| 128 | "%s expected (to close %s at line %d)", | ||
| 129 | luaX_token2str(ls, what), luaX_token2str(ls, who), where)); | ||
| 130 | } | ||
| 131 | } | ||
| 132 | } | ||
| 133 | |||
| 134 | |||
| 135 | static TString *str_checkname (LexState *ls) { | ||
| 136 | TString *ts; | ||
| 137 | check(ls, TK_NAME); | ||
| 138 | ts = ls->t.seminfo.ts; | ||
| 139 | luaX_next(ls); | ||
| 140 | return ts; | ||
| 141 | } | ||
| 142 | |||
| 143 | |||
| 144 | static void init_exp (expdesc *e, expkind k, int i) { | ||
| 145 | e->f = e->t = NO_JUMP; | ||
| 146 | e->k = k; | ||
| 147 | e->u.info = i; | ||
| 148 | } | ||
| 149 | |||
| 150 | |||
| 151 | static void codestring (LexState *ls, expdesc *e, TString *s) { | ||
| 152 | init_exp(e, VK, luaK_stringK(ls->fs, s)); | ||
| 153 | } | ||
| 154 | |||
| 155 | |||
| 156 | static void checkname (LexState *ls, expdesc *e) { | ||
| 157 | codestring(ls, e, str_checkname(ls)); | ||
| 158 | } | ||
| 159 | |||
| 160 | |||
| 161 | static int registerlocalvar (LexState *ls, TString *varname) { | ||
| 162 | FuncState *fs = ls->fs; | ||
| 163 | Proto *f = fs->f; | ||
| 164 | int oldsize = f->sizelocvars; | ||
| 165 | luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, | ||
| 166 | LocVar, SHRT_MAX, "local variables"); | ||
| 167 | while (oldsize < f->sizelocvars) | ||
| 168 | f->locvars[oldsize++].varname = NULL; | ||
| 169 | f->locvars[fs->nlocvars].varname = varname; | ||
| 170 | luaC_objbarrier(ls->L, f, varname); | ||
| 171 | return fs->nlocvars++; | ||
| 172 | } | ||
| 173 | |||
| 174 | |||
| 175 | static void new_localvar (LexState *ls, TString *name) { | ||
| 176 | FuncState *fs = ls->fs; | ||
| 177 | Dyndata *dyd = ls->dyd; | ||
| 178 | int reg = registerlocalvar(ls, name); | ||
| 179 | checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, | ||
| 180 | MAXVARS, "local variables"); | ||
| 181 | luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1, | ||
| 182 | dyd->actvar.size, Vardesc, MAX_INT, "local variables"); | ||
| 183 | dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg); | ||
| 184 | } | ||
| 185 | |||
| 186 | |||
| 187 | static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) { | ||
| 188 | new_localvar(ls, luaX_newstring(ls, name, sz)); | ||
| 189 | } | ||
| 190 | |||
| 191 | #define new_localvarliteral(ls,v) \ | ||
| 192 | new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1) | ||
| 193 | |||
| 194 | |||
| 195 | static LocVar *getlocvar (FuncState *fs, int i) { | ||
| 196 | int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx; | ||
| 197 | lua_assert(idx < fs->nlocvars); | ||
| 198 | return &fs->f->locvars[idx]; | ||
| 199 | } | ||
| 200 | |||
| 201 | |||
| 202 | static void adjustlocalvars (LexState *ls, int nvars) { | ||
| 203 | FuncState *fs = ls->fs; | ||
| 204 | fs->nactvar = cast_byte(fs->nactvar + nvars); | ||
| 205 | for (; nvars; nvars--) { | ||
| 206 | getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc; | ||
| 207 | } | ||
| 208 | } | ||
| 209 | |||
| 210 | |||
| 211 | static void removevars (FuncState *fs, int tolevel) { | ||
| 212 | fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel); | ||
| 213 | while (fs->nactvar > tolevel) | ||
| 214 | getlocvar(fs, --fs->nactvar)->endpc = fs->pc; | ||
| 215 | } | ||
| 216 | |||
| 217 | |||
| 218 | static int searchupvalue (FuncState *fs, TString *name) { | ||
| 219 | int i; | ||
| 220 | Upvaldesc *up = fs->f->upvalues; | ||
| 221 | for (i = 0; i < fs->nups; i++) { | ||
| 222 | if (eqstr(up[i].name, name)) return i; | ||
| 223 | } | ||
| 224 | return -1; /* not found */ | ||
| 225 | } | ||
| 226 | |||
| 227 | |||
| 228 | static int newupvalue (FuncState *fs, TString *name, expdesc *v) { | ||
| 229 | Proto *f = fs->f; | ||
| 230 | int oldsize = f->sizeupvalues; | ||
| 231 | checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues"); | ||
| 232 | luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues, | ||
| 233 | Upvaldesc, MAXUPVAL, "upvalues"); | ||
| 234 | while (oldsize < f->sizeupvalues) | ||
| 235 | f->upvalues[oldsize++].name = NULL; | ||
| 236 | f->upvalues[fs->nups].instack = (v->k == VLOCAL); | ||
| 237 | f->upvalues[fs->nups].idx = cast_byte(v->u.info); | ||
| 238 | f->upvalues[fs->nups].name = name; | ||
| 239 | luaC_objbarrier(fs->ls->L, f, name); | ||
| 240 | return fs->nups++; | ||
| 241 | } | ||
| 242 | |||
| 243 | |||
| 244 | static int searchvar (FuncState *fs, TString *n) { | ||
| 245 | int i; | ||
| 246 | for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) { | ||
| 247 | if (eqstr(n, getlocvar(fs, i)->varname)) | ||
| 248 | return i; | ||
| 249 | } | ||
| 250 | return -1; /* not found */ | ||
| 251 | } | ||
| 252 | |||
| 253 | |||
| 254 | /* | ||
| 255 | Mark block where variable at given level was defined | ||
| 256 | (to emit close instructions later). | ||
| 257 | */ | ||
| 258 | static void markupval (FuncState *fs, int level) { | ||
| 259 | BlockCnt *bl = fs->bl; | ||
| 260 | while (bl->nactvar > level) | ||
| 261 | bl = bl->previous; | ||
| 262 | bl->upval = 1; | ||
| 263 | } | ||
| 264 | |||
| 265 | |||
| 266 | /* | ||
| 267 | Find variable with given name 'n'. If it is an upvalue, add this | ||
| 268 | upvalue into all intermediate functions. | ||
| 269 | */ | ||
| 270 | static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { | ||
| 271 | if (fs == NULL) /* no more levels? */ | ||
| 272 | init_exp(var, VVOID, 0); /* default is global */ | ||
| 273 | else { | ||
| 274 | int v = searchvar(fs, n); /* look up locals at current level */ | ||
| 275 | if (v >= 0) { /* found? */ | ||
| 276 | init_exp(var, VLOCAL, v); /* variable is local */ | ||
| 277 | if (!base) | ||
| 278 | markupval(fs, v); /* local will be used as an upval */ | ||
| 279 | } | ||
| 280 | else { /* not found as local at current level; try upvalues */ | ||
| 281 | int idx = searchupvalue(fs, n); /* try existing upvalues */ | ||
| 282 | if (idx < 0) { /* not found? */ | ||
| 283 | singlevaraux(fs->prev, n, var, 0); /* try upper levels */ | ||
| 284 | if (var->k == VVOID) /* not found? */ | ||
| 285 | return; /* it is a global */ | ||
| 286 | /* else was LOCAL or UPVAL */ | ||
| 287 | idx = newupvalue(fs, n, var); /* will be a new upvalue */ | ||
| 288 | } | ||
| 289 | init_exp(var, VUPVAL, idx); /* new or old upvalue */ | ||
| 290 | } | ||
| 291 | } | ||
| 292 | } | ||
| 293 | |||
| 294 | |||
| 295 | static void singlevar (LexState *ls, expdesc *var) { | ||
| 296 | TString *varname = str_checkname(ls); | ||
| 297 | FuncState *fs = ls->fs; | ||
| 298 | singlevaraux(fs, varname, var, 1); | ||
| 299 | if (var->k == VVOID) { /* global name? */ | ||
| 300 | expdesc key; | ||
| 301 | singlevaraux(fs, ls->envn, var, 1); /* get environment variable */ | ||
| 302 | lua_assert(var->k != VVOID); /* this one must exist */ | ||
| 303 | codestring(ls, &key, varname); /* key is variable name */ | ||
| 304 | luaK_indexed(fs, var, &key); /* env[varname] */ | ||
| 305 | } | ||
| 306 | } | ||
| 307 | |||
| 308 | |||
| 309 | static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { | ||
| 310 | FuncState *fs = ls->fs; | ||
| 311 | int extra = nvars - nexps; | ||
| 312 | if (hasmultret(e->k)) { | ||
| 313 | extra++; /* includes call itself */ | ||
| 314 | if (extra < 0) extra = 0; | ||
| 315 | luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ | ||
| 316 | if (extra > 1) luaK_reserveregs(fs, extra-1); | ||
| 317 | } | ||
| 318 | else { | ||
| 319 | if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ | ||
| 320 | if (extra > 0) { | ||
| 321 | int reg = fs->freereg; | ||
| 322 | luaK_reserveregs(fs, extra); | ||
| 323 | luaK_nil(fs, reg, extra); | ||
| 324 | } | ||
| 325 | } | ||
| 326 | if (nexps > nvars) | ||
| 327 | ls->fs->freereg -= nexps - nvars; /* remove extra values */ | ||
| 328 | } | ||
| 329 | |||
| 330 | |||
| 331 | static void enterlevel (LexState *ls) { | ||
| 332 | lua_State *L = ls->L; | ||
| 333 | ++L->nCcalls; | ||
| 334 | checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels"); | ||
| 335 | } | ||
| 336 | |||
| 337 | |||
| 338 | #define leavelevel(ls) ((ls)->L->nCcalls--) | ||
| 339 | |||
| 340 | |||
| 341 | static void closegoto (LexState *ls, int g, Labeldesc *label) { | ||
| 342 | int i; | ||
| 343 | FuncState *fs = ls->fs; | ||
| 344 | Labellist *gl = &ls->dyd->gt; | ||
| 345 | Labeldesc *gt = &gl->arr[g]; | ||
| 346 | lua_assert(eqstr(gt->name, label->name)); | ||
| 347 | if (gt->nactvar < label->nactvar) { | ||
| 348 | TString *vname = getlocvar(fs, gt->nactvar)->varname; | ||
| 349 | const char *msg = luaO_pushfstring(ls->L, | ||
| 350 | "<goto %s> at line %d jumps into the scope of local '%s'", | ||
| 351 | getstr(gt->name), gt->line, getstr(vname)); | ||
| 352 | semerror(ls, msg); | ||
| 353 | } | ||
| 354 | luaK_patchlist(fs, gt->pc, label->pc); | ||
| 355 | /* remove goto from pending list */ | ||
| 356 | for (i = g; i < gl->n - 1; i++) | ||
| 357 | gl->arr[i] = gl->arr[i + 1]; | ||
| 358 | gl->n--; | ||
| 359 | } | ||
| 360 | |||
| 361 | |||
| 362 | /* | ||
| 363 | ** try to close a goto with existing labels; this solves backward jumps | ||
| 364 | */ | ||
| 365 | static int findlabel (LexState *ls, int g) { | ||
| 366 | int i; | ||
| 367 | BlockCnt *bl = ls->fs->bl; | ||
| 368 | Dyndata *dyd = ls->dyd; | ||
| 369 | Labeldesc *gt = &dyd->gt.arr[g]; | ||
| 370 | /* check labels in current block for a match */ | ||
| 371 | for (i = bl->firstlabel; i < dyd->label.n; i++) { | ||
| 372 | Labeldesc *lb = &dyd->label.arr[i]; | ||
| 373 | if (eqstr(lb->name, gt->name)) { /* correct label? */ | ||
| 374 | if (gt->nactvar > lb->nactvar && | ||
| 375 | (bl->upval || dyd->label.n > bl->firstlabel)) | ||
| 376 | luaK_patchclose(ls->fs, gt->pc, lb->nactvar); | ||
| 377 | closegoto(ls, g, lb); /* close it */ | ||
| 378 | return 1; | ||
| 379 | } | ||
| 380 | } | ||
| 381 | return 0; /* label not found; cannot close goto */ | ||
| 382 | } | ||
| 383 | |||
| 384 | |||
| 385 | static int newlabelentry (LexState *ls, Labellist *l, TString *name, | ||
| 386 | int line, int pc) { | ||
| 387 | int n = l->n; | ||
| 388 | luaM_growvector(ls->L, l->arr, n, l->size, | ||
| 389 | Labeldesc, SHRT_MAX, "labels/gotos"); | ||
| 390 | l->arr[n].name = name; | ||
| 391 | l->arr[n].line = line; | ||
| 392 | l->arr[n].nactvar = ls->fs->nactvar; | ||
| 393 | l->arr[n].pc = pc; | ||
| 394 | l->n = n + 1; | ||
| 395 | return n; | ||
| 396 | } | ||
| 397 | |||
| 398 | |||
| 399 | /* | ||
| 400 | ** check whether new label 'lb' matches any pending gotos in current | ||
| 401 | ** block; solves forward jumps | ||
| 402 | */ | ||
| 403 | static void findgotos (LexState *ls, Labeldesc *lb) { | ||
| 404 | Labellist *gl = &ls->dyd->gt; | ||
| 405 | int i = ls->fs->bl->firstgoto; | ||
| 406 | while (i < gl->n) { | ||
| 407 | if (eqstr(gl->arr[i].name, lb->name)) | ||
| 408 | closegoto(ls, i, lb); | ||
| 409 | else | ||
| 410 | i++; | ||
| 411 | } | ||
| 412 | } | ||
| 413 | |||
| 414 | |||
| 415 | /* | ||
| 416 | ** export pending gotos to outer level, to check them against | ||
| 417 | ** outer labels; if the block being exited has upvalues, and | ||
| 418 | ** the goto exits the scope of any variable (which can be the | ||
| 419 | ** upvalue), close those variables being exited. | ||
| 420 | */ | ||
| 421 | static void movegotosout (FuncState *fs, BlockCnt *bl) { | ||
| 422 | int i = bl->firstgoto; | ||
| 423 | Labellist *gl = &fs->ls->dyd->gt; | ||
| 424 | /* correct pending gotos to current block and try to close it | ||
| 425 | with visible labels */ | ||
| 426 | while (i < gl->n) { | ||
| 427 | Labeldesc *gt = &gl->arr[i]; | ||
| 428 | if (gt->nactvar > bl->nactvar) { | ||
| 429 | if (bl->upval) | ||
| 430 | luaK_patchclose(fs, gt->pc, bl->nactvar); | ||
| 431 | gt->nactvar = bl->nactvar; | ||
| 432 | } | ||
| 433 | if (!findlabel(fs->ls, i)) | ||
| 434 | i++; /* move to next one */ | ||
| 435 | } | ||
| 436 | } | ||
| 437 | |||
| 438 | |||
| 439 | static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) { | ||
| 440 | bl->isloop = isloop; | ||
| 441 | bl->nactvar = fs->nactvar; | ||
| 442 | bl->firstlabel = fs->ls->dyd->label.n; | ||
| 443 | bl->firstgoto = fs->ls->dyd->gt.n; | ||
| 444 | bl->upval = 0; | ||
| 445 | bl->previous = fs->bl; | ||
| 446 | fs->bl = bl; | ||
| 447 | lua_assert(fs->freereg == fs->nactvar); | ||
| 448 | } | ||
| 449 | |||
| 450 | |||
| 451 | /* | ||
| 452 | ** create a label named 'break' to resolve break statements | ||
| 453 | */ | ||
| 454 | static void breaklabel (LexState *ls) { | ||
| 455 | TString *n = luaS_new(ls->L, "break"); | ||
| 456 | int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc); | ||
| 457 | findgotos(ls, &ls->dyd->label.arr[l]); | ||
| 458 | } | ||
| 459 | |||
| 460 | /* | ||
| 461 | ** generates an error for an undefined 'goto'; choose appropriate | ||
| 462 | ** message when label name is a reserved word (which can only be 'break') | ||
| 463 | */ | ||
| 464 | static l_noret undefgoto (LexState *ls, Labeldesc *gt) { | ||
| 465 | const char *msg = isreserved(gt->name) | ||
| 466 | ? "<%s> at line %d not inside a loop" | ||
| 467 | : "no visible label '%s' for <goto> at line %d"; | ||
| 468 | msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line); | ||
| 469 | semerror(ls, msg); | ||
| 470 | } | ||
| 471 | |||
| 472 | |||
| 473 | static void leaveblock (FuncState *fs) { | ||
| 474 | BlockCnt *bl = fs->bl; | ||
| 475 | LexState *ls = fs->ls; | ||
| 476 | if (bl->previous && bl->upval) { | ||
| 477 | /* create a 'jump to here' to close upvalues */ | ||
| 478 | int j = luaK_jump(fs); | ||
| 479 | luaK_patchclose(fs, j, bl->nactvar); | ||
| 480 | luaK_patchtohere(fs, j); | ||
| 481 | } | ||
| 482 | if (bl->isloop) | ||
| 483 | breaklabel(ls); /* close pending breaks */ | ||
| 484 | fs->bl = bl->previous; | ||
| 485 | removevars(fs, bl->nactvar); | ||
| 486 | lua_assert(bl->nactvar == fs->nactvar); | ||
| 487 | fs->freereg = fs->nactvar; /* free registers */ | ||
| 488 | ls->dyd->label.n = bl->firstlabel; /* remove local labels */ | ||
| 489 | if (bl->previous) /* inner block? */ | ||
| 490 | movegotosout(fs, bl); /* update pending gotos to outer block */ | ||
| 491 | else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */ | ||
| 492 | undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */ | ||
| 493 | } | ||
| 494 | |||
| 495 | |||
| 496 | /* | ||
| 497 | ** adds a new prototype into list of prototypes | ||
| 498 | */ | ||
| 499 | static Proto *addprototype (LexState *ls) { | ||
| 500 | Proto *clp; | ||
| 501 | lua_State *L = ls->L; | ||
| 502 | FuncState *fs = ls->fs; | ||
| 503 | Proto *f = fs->f; /* prototype of current function */ | ||
| 504 | if (fs->np >= f->sizep) { | ||
| 505 | int oldsize = f->sizep; | ||
| 506 | luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions"); | ||
| 507 | while (oldsize < f->sizep) | ||
| 508 | f->p[oldsize++] = NULL; | ||
| 509 | } | ||
| 510 | f->p[fs->np++] = clp = luaF_newproto(L); | ||
| 511 | luaC_objbarrier(L, f, clp); | ||
| 512 | return clp; | ||
| 513 | } | ||
| 514 | |||
| 515 | |||
| 516 | /* | ||
| 517 | ** codes instruction to create new closure in parent function. | ||
| 518 | ** The OP_CLOSURE instruction must use the last available register, | ||
| 519 | ** so that, if it invokes the GC, the GC knows which registers | ||
| 520 | ** are in use at that time. | ||
| 521 | */ | ||
| 522 | static void codeclosure (LexState *ls, expdesc *v) { | ||
| 523 | FuncState *fs = ls->fs->prev; | ||
| 524 | init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1)); | ||
| 525 | luaK_exp2nextreg(fs, v); /* fix it at the last register */ | ||
| 526 | } | ||
| 527 | |||
| 528 | |||
| 529 | static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { | ||
| 530 | Proto *f; | ||
| 531 | fs->prev = ls->fs; /* linked list of funcstates */ | ||
| 532 | fs->ls = ls; | ||
| 533 | ls->fs = fs; | ||
| 534 | fs->pc = 0; | ||
| 535 | fs->lasttarget = 0; | ||
| 536 | fs->jpc = NO_JUMP; | ||
| 537 | fs->freereg = 0; | ||
| 538 | fs->nk = 0; | ||
| 539 | fs->np = 0; | ||
| 540 | fs->nups = 0; | ||
| 541 | fs->nlocvars = 0; | ||
| 542 | fs->nactvar = 0; | ||
| 543 | fs->firstlocal = ls->dyd->actvar.n; | ||
| 544 | fs->bl = NULL; | ||
| 545 | f = fs->f; | ||
| 546 | f->source = ls->source; | ||
| 547 | f->maxstacksize = 2; /* registers 0/1 are always valid */ | ||
| 548 | enterblock(fs, bl, 0); | ||
| 549 | } | ||
| 550 | |||
| 551 | |||
| 552 | static void close_func (LexState *ls) { | ||
| 553 | lua_State *L = ls->L; | ||
| 554 | FuncState *fs = ls->fs; | ||
| 555 | Proto *f = fs->f; | ||
| 556 | luaK_ret(fs, 0, 0); /* final return */ | ||
| 557 | leaveblock(fs); | ||
| 558 | luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); | ||
| 559 | f->sizecode = fs->pc; | ||
| 560 | luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); | ||
| 561 | f->sizelineinfo = fs->pc; | ||
| 562 | luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue); | ||
| 563 | f->sizek = fs->nk; | ||
| 564 | luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); | ||
| 565 | f->sizep = fs->np; | ||
| 566 | luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); | ||
| 567 | f->sizelocvars = fs->nlocvars; | ||
| 568 | luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); | ||
| 569 | f->sizeupvalues = fs->nups; | ||
| 570 | lua_assert(fs->bl == NULL); | ||
| 571 | ls->fs = fs->prev; | ||
| 572 | luaC_checkGC(L); | ||
| 573 | } | ||
| 574 | |||
| 575 | |||
| 576 | |||
| 577 | /*============================================================*/ | ||
| 578 | /* GRAMMAR RULES */ | ||
| 579 | /*============================================================*/ | ||
| 580 | |||
| 581 | |||
| 582 | /* | ||
| 583 | ** check whether current token is in the follow set of a block. | ||
| 584 | ** 'until' closes syntactical blocks, but do not close scope, | ||
| 585 | ** so it is handled in separate. | ||
| 586 | */ | ||
| 587 | static int block_follow (LexState *ls, int withuntil) { | ||
| 588 | switch (ls->t.token) { | ||
| 589 | case TK_ELSE: case TK_ELSEIF: | ||
| 590 | case TK_END: case TK_EOS: | ||
| 591 | return 1; | ||
| 592 | case TK_UNTIL: return withuntil; | ||
| 593 | default: return 0; | ||
| 594 | } | ||
| 595 | } | ||
| 596 | |||
| 597 | |||
| 598 | static void statlist (LexState *ls) { | ||
| 599 | /* statlist -> { stat [';'] } */ | ||
| 600 | while (!block_follow(ls, 1)) { | ||
| 601 | if (ls->t.token == TK_RETURN) { | ||
| 602 | statement(ls); | ||
| 603 | return; /* 'return' must be last statement */ | ||
| 604 | } | ||
| 605 | statement(ls); | ||
| 606 | } | ||
| 607 | } | ||
| 608 | |||
| 609 | |||
| 610 | static void fieldsel (LexState *ls, expdesc *v) { | ||
| 611 | /* fieldsel -> ['.' | ':'] NAME */ | ||
| 612 | FuncState *fs = ls->fs; | ||
| 613 | expdesc key; | ||
| 614 | luaK_exp2anyregup(fs, v); | ||
| 615 | luaX_next(ls); /* skip the dot or colon */ | ||
| 616 | checkname(ls, &key); | ||
| 617 | luaK_indexed(fs, v, &key); | ||
| 618 | } | ||
| 619 | |||
| 620 | |||
| 621 | static void yindex (LexState *ls, expdesc *v) { | ||
| 622 | /* index -> '[' expr ']' */ | ||
| 623 | luaX_next(ls); /* skip the '[' */ | ||
| 624 | expr(ls, v); | ||
| 625 | luaK_exp2val(ls->fs, v); | ||
| 626 | checknext(ls, ']'); | ||
| 627 | } | ||
| 628 | |||
| 629 | |||
| 630 | /* | ||
| 631 | ** {====================================================================== | ||
| 632 | ** Rules for Constructors | ||
| 633 | ** ======================================================================= | ||
| 634 | */ | ||
| 635 | |||
| 636 | |||
| 637 | struct ConsControl { | ||
| 638 | expdesc v; /* last list item read */ | ||
| 639 | expdesc *t; /* table descriptor */ | ||
| 640 | int nh; /* total number of 'record' elements */ | ||
| 641 | int na; /* total number of array elements */ | ||
| 642 | int tostore; /* number of array elements pending to be stored */ | ||
| 643 | }; | ||
| 644 | |||
| 645 | |||
| 646 | static void recfield (LexState *ls, struct ConsControl *cc) { | ||
| 647 | /* recfield -> (NAME | '['exp1']') = exp1 */ | ||
| 648 | FuncState *fs = ls->fs; | ||
| 649 | int reg = ls->fs->freereg; | ||
| 650 | expdesc key, val; | ||
| 651 | int rkkey; | ||
| 652 | if (ls->t.token == TK_NAME) { | ||
| 653 | checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); | ||
| 654 | checkname(ls, &key); | ||
| 655 | } | ||
| 656 | else /* ls->t.token == '[' */ | ||
| 657 | yindex(ls, &key); | ||
| 658 | cc->nh++; | ||
| 659 | checknext(ls, '='); | ||
| 660 | rkkey = luaK_exp2RK(fs, &key); | ||
| 661 | expr(ls, &val); | ||
| 662 | luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val)); | ||
| 663 | fs->freereg = reg; /* free registers */ | ||
| 664 | } | ||
| 665 | |||
| 666 | |||
| 667 | static void closelistfield (FuncState *fs, struct ConsControl *cc) { | ||
| 668 | if (cc->v.k == VVOID) return; /* there is no list item */ | ||
| 669 | luaK_exp2nextreg(fs, &cc->v); | ||
| 670 | cc->v.k = VVOID; | ||
| 671 | if (cc->tostore == LFIELDS_PER_FLUSH) { | ||
| 672 | luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ | ||
| 673 | cc->tostore = 0; /* no more items pending */ | ||
| 674 | } | ||
| 675 | } | ||
| 676 | |||
| 677 | |||
| 678 | static void lastlistfield (FuncState *fs, struct ConsControl *cc) { | ||
| 679 | if (cc->tostore == 0) return; | ||
| 680 | if (hasmultret(cc->v.k)) { | ||
| 681 | luaK_setmultret(fs, &cc->v); | ||
| 682 | luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET); | ||
| 683 | cc->na--; /* do not count last expression (unknown number of elements) */ | ||
| 684 | } | ||
| 685 | else { | ||
| 686 | if (cc->v.k != VVOID) | ||
| 687 | luaK_exp2nextreg(fs, &cc->v); | ||
| 688 | luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); | ||
| 689 | } | ||
| 690 | } | ||
| 691 | |||
| 692 | |||
| 693 | static void listfield (LexState *ls, struct ConsControl *cc) { | ||
| 694 | /* listfield -> exp */ | ||
| 695 | expr(ls, &cc->v); | ||
| 696 | checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); | ||
| 697 | cc->na++; | ||
| 698 | cc->tostore++; | ||
| 699 | } | ||
| 700 | |||
| 701 | |||
| 702 | static void field (LexState *ls, struct ConsControl *cc) { | ||
| 703 | /* field -> listfield | recfield */ | ||
| 704 | switch(ls->t.token) { | ||
| 705 | case TK_NAME: { /* may be 'listfield' or 'recfield' */ | ||
| 706 | if (luaX_lookahead(ls) != '=') /* expression? */ | ||
| 707 | listfield(ls, cc); | ||
| 708 | else | ||
| 709 | recfield(ls, cc); | ||
| 710 | break; | ||
| 711 | } | ||
| 712 | case '[': { | ||
| 713 | recfield(ls, cc); | ||
| 714 | break; | ||
| 715 | } | ||
| 716 | default: { | ||
| 717 | listfield(ls, cc); | ||
| 718 | break; | ||
| 719 | } | ||
| 720 | } | ||
| 721 | } | ||
| 722 | |||
| 723 | |||
| 724 | static void constructor (LexState *ls, expdesc *t) { | ||
| 725 | /* constructor -> '{' [ field { sep field } [sep] ] '}' | ||
| 726 | sep -> ',' | ';' */ | ||
| 727 | FuncState *fs = ls->fs; | ||
| 728 | int line = ls->linenumber; | ||
| 729 | int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); | ||
| 730 | struct ConsControl cc; | ||
| 731 | cc.na = cc.nh = cc.tostore = 0; | ||
| 732 | cc.t = t; | ||
| 733 | init_exp(t, VRELOCABLE, pc); | ||
| 734 | init_exp(&cc.v, VVOID, 0); /* no value (yet) */ | ||
| 735 | luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */ | ||
| 736 | checknext(ls, '{'); | ||
| 737 | do { | ||
| 738 | lua_assert(cc.v.k == VVOID || cc.tostore > 0); | ||
| 739 | if (ls->t.token == '}') break; | ||
| 740 | closelistfield(fs, &cc); | ||
| 741 | field(ls, &cc); | ||
| 742 | } while (testnext(ls, ',') || testnext(ls, ';')); | ||
| 743 | check_match(ls, '}', '{', line); | ||
| 744 | lastlistfield(fs, &cc); | ||
| 745 | SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ | ||
| 746 | SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */ | ||
| 747 | } | ||
| 748 | |||
| 749 | /* }====================================================================== */ | ||
| 750 | |||
| 751 | |||
| 752 | |||
| 753 | static void parlist (LexState *ls) { | ||
| 754 | /* parlist -> [ param { ',' param } ] */ | ||
| 755 | FuncState *fs = ls->fs; | ||
| 756 | Proto *f = fs->f; | ||
| 757 | int nparams = 0; | ||
| 758 | f->is_vararg = 0; | ||
| 759 | if (ls->t.token != ')') { /* is 'parlist' not empty? */ | ||
| 760 | do { | ||
| 761 | switch (ls->t.token) { | ||
| 762 | case TK_NAME: { /* param -> NAME */ | ||
| 763 | new_localvar(ls, str_checkname(ls)); | ||
| 764 | nparams++; | ||
| 765 | break; | ||
| 766 | } | ||
| 767 | case TK_DOTS: { /* param -> '...' */ | ||
| 768 | luaX_next(ls); | ||
| 769 | f->is_vararg = 1; /* declared vararg */ | ||
| 770 | break; | ||
| 771 | } | ||
| 772 | default: luaX_syntaxerror(ls, "<name> or '...' expected"); | ||
| 773 | } | ||
| 774 | } while (!f->is_vararg && testnext(ls, ',')); | ||
| 775 | } | ||
| 776 | adjustlocalvars(ls, nparams); | ||
| 777 | f->numparams = cast_byte(fs->nactvar); | ||
| 778 | luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ | ||
| 779 | } | ||
| 780 | |||
| 781 | |||
| 782 | static void body (LexState *ls, expdesc *e, int ismethod, int line) { | ||
| 783 | /* body -> '(' parlist ')' block END */ | ||
| 784 | FuncState new_fs; | ||
| 785 | BlockCnt bl; | ||
| 786 | new_fs.f = addprototype(ls); | ||
| 787 | new_fs.f->linedefined = line; | ||
| 788 | open_func(ls, &new_fs, &bl); | ||
| 789 | checknext(ls, '('); | ||
| 790 | if (ismethod) { | ||
| 791 | new_localvarliteral(ls, "self"); /* create 'self' parameter */ | ||
| 792 | adjustlocalvars(ls, 1); | ||
| 793 | } | ||
| 794 | parlist(ls); | ||
| 795 | checknext(ls, ')'); | ||
| 796 | statlist(ls); | ||
| 797 | new_fs.f->lastlinedefined = ls->linenumber; | ||
| 798 | check_match(ls, TK_END, TK_FUNCTION, line); | ||
| 799 | codeclosure(ls, e); | ||
| 800 | close_func(ls); | ||
| 801 | } | ||
| 802 | |||
| 803 | |||
| 804 | static int explist (LexState *ls, expdesc *v) { | ||
| 805 | /* explist -> expr { ',' expr } */ | ||
| 806 | int n = 1; /* at least one expression */ | ||
| 807 | expr(ls, v); | ||
| 808 | while (testnext(ls, ',')) { | ||
| 809 | luaK_exp2nextreg(ls->fs, v); | ||
| 810 | expr(ls, v); | ||
| 811 | n++; | ||
| 812 | } | ||
| 813 | return n; | ||
| 814 | } | ||
| 815 | |||
| 816 | |||
| 817 | static void funcargs (LexState *ls, expdesc *f, int line) { | ||
| 818 | FuncState *fs = ls->fs; | ||
| 819 | expdesc args; | ||
| 820 | int base, nparams; | ||
| 821 | switch (ls->t.token) { | ||
| 822 | case '(': { /* funcargs -> '(' [ explist ] ')' */ | ||
| 823 | luaX_next(ls); | ||
| 824 | if (ls->t.token == ')') /* arg list is empty? */ | ||
| 825 | args.k = VVOID; | ||
| 826 | else { | ||
| 827 | explist(ls, &args); | ||
| 828 | luaK_setmultret(fs, &args); | ||
| 829 | } | ||
| 830 | check_match(ls, ')', '(', line); | ||
| 831 | break; | ||
| 832 | } | ||
| 833 | case '{': { /* funcargs -> constructor */ | ||
| 834 | constructor(ls, &args); | ||
| 835 | break; | ||
| 836 | } | ||
| 837 | case TK_STRING: { /* funcargs -> STRING */ | ||
| 838 | codestring(ls, &args, ls->t.seminfo.ts); | ||
| 839 | luaX_next(ls); /* must use 'seminfo' before 'next' */ | ||
| 840 | break; | ||
| 841 | } | ||
| 842 | default: { | ||
| 843 | luaX_syntaxerror(ls, "function arguments expected"); | ||
| 844 | } | ||
| 845 | } | ||
| 846 | lua_assert(f->k == VNONRELOC); | ||
| 847 | base = f->u.info; /* base register for call */ | ||
| 848 | if (hasmultret(args.k)) | ||
| 849 | nparams = LUA_MULTRET; /* open call */ | ||
| 850 | else { | ||
| 851 | if (args.k != VVOID) | ||
| 852 | luaK_exp2nextreg(fs, &args); /* close last argument */ | ||
| 853 | nparams = fs->freereg - (base+1); | ||
| 854 | } | ||
| 855 | init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); | ||
| 856 | luaK_fixline(fs, line); | ||
| 857 | fs->freereg = base+1; /* call remove function and arguments and leaves | ||
| 858 | (unless changed) one result */ | ||
| 859 | } | ||
| 860 | |||
| 861 | |||
| 862 | |||
| 863 | |||
| 864 | /* | ||
| 865 | ** {====================================================================== | ||
| 866 | ** Expression parsing | ||
| 867 | ** ======================================================================= | ||
| 868 | */ | ||
| 869 | |||
| 870 | |||
| 871 | static void primaryexp (LexState *ls, expdesc *v) { | ||
| 872 | /* primaryexp -> NAME | '(' expr ')' */ | ||
| 873 | switch (ls->t.token) { | ||
| 874 | case '(': { | ||
| 875 | int line = ls->linenumber; | ||
| 876 | luaX_next(ls); | ||
| 877 | expr(ls, v); | ||
| 878 | check_match(ls, ')', '(', line); | ||
| 879 | luaK_dischargevars(ls->fs, v); | ||
| 880 | return; | ||
| 881 | } | ||
| 882 | case TK_NAME: { | ||
| 883 | singlevar(ls, v); | ||
| 884 | return; | ||
| 885 | } | ||
| 886 | default: { | ||
| 887 | luaX_syntaxerror(ls, "unexpected symbol"); | ||
| 888 | } | ||
| 889 | } | ||
| 890 | } | ||
| 891 | |||
| 892 | |||
| 893 | static void suffixedexp (LexState *ls, expdesc *v) { | ||
| 894 | /* suffixedexp -> | ||
| 895 | primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */ | ||
| 896 | FuncState *fs = ls->fs; | ||
| 897 | int line = ls->linenumber; | ||
| 898 | primaryexp(ls, v); | ||
| 899 | for (;;) { | ||
| 900 | switch (ls->t.token) { | ||
| 901 | case '.': { /* fieldsel */ | ||
| 902 | fieldsel(ls, v); | ||
| 903 | break; | ||
| 904 | } | ||
| 905 | case '[': { /* '[' exp1 ']' */ | ||
| 906 | expdesc key; | ||
| 907 | luaK_exp2anyregup(fs, v); | ||
| 908 | yindex(ls, &key); | ||
| 909 | luaK_indexed(fs, v, &key); | ||
| 910 | break; | ||
| 911 | } | ||
| 912 | case ':': { /* ':' NAME funcargs */ | ||
| 913 | expdesc key; | ||
| 914 | luaX_next(ls); | ||
| 915 | checkname(ls, &key); | ||
| 916 | luaK_self(fs, v, &key); | ||
| 917 | funcargs(ls, v, line); | ||
| 918 | break; | ||
| 919 | } | ||
| 920 | case '(': case TK_STRING: case '{': { /* funcargs */ | ||
| 921 | luaK_exp2nextreg(fs, v); | ||
| 922 | funcargs(ls, v, line); | ||
| 923 | break; | ||
| 924 | } | ||
| 925 | default: return; | ||
| 926 | } | ||
| 927 | } | ||
| 928 | } | ||
| 929 | |||
| 930 | |||
| 931 | static void simpleexp (LexState *ls, expdesc *v) { | ||
| 932 | /* simpleexp -> FLT | INT | STRING | NIL | TRUE | FALSE | ... | | ||
| 933 | constructor | FUNCTION body | suffixedexp */ | ||
| 934 | switch (ls->t.token) { | ||
| 935 | case TK_FLT: { | ||
| 936 | init_exp(v, VKFLT, 0); | ||
| 937 | v->u.nval = ls->t.seminfo.r; | ||
| 938 | break; | ||
| 939 | } | ||
| 940 | case TK_INT: { | ||
| 941 | init_exp(v, VKINT, 0); | ||
| 942 | v->u.ival = ls->t.seminfo.i; | ||
| 943 | break; | ||
| 944 | } | ||
| 945 | case TK_STRING: { | ||
| 946 | codestring(ls, v, ls->t.seminfo.ts); | ||
| 947 | break; | ||
| 948 | } | ||
| 949 | case TK_NIL: { | ||
| 950 | init_exp(v, VNIL, 0); | ||
| 951 | break; | ||
| 952 | } | ||
| 953 | case TK_TRUE: { | ||
| 954 | init_exp(v, VTRUE, 0); | ||
| 955 | break; | ||
| 956 | } | ||
| 957 | case TK_FALSE: { | ||
| 958 | init_exp(v, VFALSE, 0); | ||
| 959 | break; | ||
| 960 | } | ||
| 961 | case TK_DOTS: { /* vararg */ | ||
| 962 | FuncState *fs = ls->fs; | ||
| 963 | check_condition(ls, fs->f->is_vararg, | ||
| 964 | "cannot use '...' outside a vararg function"); | ||
| 965 | init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0)); | ||
| 966 | break; | ||
| 967 | } | ||
| 968 | case '{': { /* constructor */ | ||
| 969 | constructor(ls, v); | ||
| 970 | return; | ||
| 971 | } | ||
| 972 | case TK_FUNCTION: { | ||
| 973 | luaX_next(ls); | ||
| 974 | body(ls, v, 0, ls->linenumber); | ||
| 975 | return; | ||
| 976 | } | ||
| 977 | default: { | ||
| 978 | suffixedexp(ls, v); | ||
| 979 | return; | ||
| 980 | } | ||
| 981 | } | ||
| 982 | luaX_next(ls); | ||
| 983 | } | ||
| 984 | |||
| 985 | |||
| 986 | static UnOpr getunopr (int op) { | ||
| 987 | switch (op) { | ||
| 988 | case TK_NOT: return OPR_NOT; | ||
| 989 | case '-': return OPR_MINUS; | ||
| 990 | case '~': return OPR_BNOT; | ||
| 991 | case '#': return OPR_LEN; | ||
| 992 | default: return OPR_NOUNOPR; | ||
| 993 | } | ||
| 994 | } | ||
| 995 | |||
| 996 | |||
| 997 | static BinOpr getbinopr (int op) { | ||
| 998 | switch (op) { | ||
| 999 | case '+': return OPR_ADD; | ||
| 1000 | case '-': return OPR_SUB; | ||
| 1001 | case '*': return OPR_MUL; | ||
| 1002 | case '%': return OPR_MOD; | ||
| 1003 | case '^': return OPR_POW; | ||
| 1004 | case '/': return OPR_DIV; | ||
| 1005 | case TK_IDIV: return OPR_IDIV; | ||
| 1006 | case '&': return OPR_BAND; | ||
| 1007 | case '|': return OPR_BOR; | ||
| 1008 | case '~': return OPR_BXOR; | ||
| 1009 | case TK_SHL: return OPR_SHL; | ||
| 1010 | case TK_SHR: return OPR_SHR; | ||
| 1011 | case TK_CONCAT: return OPR_CONCAT; | ||
| 1012 | case TK_NE: return OPR_NE; | ||
| 1013 | case TK_EQ: return OPR_EQ; | ||
| 1014 | case '<': return OPR_LT; | ||
| 1015 | case TK_LE: return OPR_LE; | ||
| 1016 | case '>': return OPR_GT; | ||
| 1017 | case TK_GE: return OPR_GE; | ||
| 1018 | case TK_AND: return OPR_AND; | ||
| 1019 | case TK_OR: return OPR_OR; | ||
| 1020 | default: return OPR_NOBINOPR; | ||
| 1021 | } | ||
| 1022 | } | ||
| 1023 | |||
| 1024 | |||
| 1025 | static const struct { | ||
| 1026 | lu_byte left; /* left priority for each binary operator */ | ||
| 1027 | lu_byte right; /* right priority */ | ||
| 1028 | } priority[] = { /* ORDER OPR */ | ||
| 1029 | {10, 10}, {10, 10}, /* '+' '-' */ | ||
| 1030 | {11, 11}, {11, 11}, /* '*' '%' */ | ||
| 1031 | {14, 13}, /* '^' (right associative) */ | ||
| 1032 | {11, 11}, {11, 11}, /* '/' '//' */ | ||
| 1033 | {6, 6}, {4, 4}, {5, 5}, /* '&' '|' '~' */ | ||
| 1034 | {7, 7}, {7, 7}, /* '<<' '>>' */ | ||
| 1035 | {9, 8}, /* '..' (right associative) */ | ||
| 1036 | {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */ | ||
| 1037 | {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */ | ||
| 1038 | {2, 2}, {1, 1} /* and, or */ | ||
| 1039 | }; | ||
| 1040 | |||
| 1041 | #define UNARY_PRIORITY 12 /* priority for unary operators */ | ||
| 1042 | |||
| 1043 | |||
| 1044 | /* | ||
| 1045 | ** subexpr -> (simpleexp | unop subexpr) { binop subexpr } | ||
| 1046 | ** where 'binop' is any binary operator with a priority higher than 'limit' | ||
| 1047 | */ | ||
| 1048 | static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { | ||
| 1049 | BinOpr op; | ||
| 1050 | UnOpr uop; | ||
| 1051 | enterlevel(ls); | ||
| 1052 | uop = getunopr(ls->t.token); | ||
| 1053 | if (uop != OPR_NOUNOPR) { | ||
| 1054 | int line = ls->linenumber; | ||
| 1055 | luaX_next(ls); | ||
| 1056 | subexpr(ls, v, UNARY_PRIORITY); | ||
| 1057 | luaK_prefix(ls->fs, uop, v, line); | ||
| 1058 | } | ||
| 1059 | else simpleexp(ls, v); | ||
| 1060 | /* expand while operators have priorities higher than 'limit' */ | ||
| 1061 | op = getbinopr(ls->t.token); | ||
| 1062 | while (op != OPR_NOBINOPR && priority[op].left > limit) { | ||
| 1063 | expdesc v2; | ||
| 1064 | BinOpr nextop; | ||
| 1065 | int line = ls->linenumber; | ||
| 1066 | luaX_next(ls); | ||
| 1067 | luaK_infix(ls->fs, op, v); | ||
| 1068 | /* read sub-expression with higher priority */ | ||
| 1069 | nextop = subexpr(ls, &v2, priority[op].right); | ||
| 1070 | luaK_posfix(ls->fs, op, v, &v2, line); | ||
| 1071 | op = nextop; | ||
| 1072 | } | ||
| 1073 | leavelevel(ls); | ||
| 1074 | return op; /* return first untreated operator */ | ||
| 1075 | } | ||
| 1076 | |||
| 1077 | |||
| 1078 | static void expr (LexState *ls, expdesc *v) { | ||
| 1079 | subexpr(ls, v, 0); | ||
| 1080 | } | ||
| 1081 | |||
| 1082 | /* }==================================================================== */ | ||
| 1083 | |||
| 1084 | |||
| 1085 | |||
| 1086 | /* | ||
| 1087 | ** {====================================================================== | ||
| 1088 | ** Rules for Statements | ||
| 1089 | ** ======================================================================= | ||
| 1090 | */ | ||
| 1091 | |||
| 1092 | |||
| 1093 | static void block (LexState *ls) { | ||
| 1094 | /* block -> statlist */ | ||
| 1095 | FuncState *fs = ls->fs; | ||
| 1096 | BlockCnt bl; | ||
| 1097 | enterblock(fs, &bl, 0); | ||
| 1098 | statlist(ls); | ||
| 1099 | leaveblock(fs); | ||
| 1100 | } | ||
| 1101 | |||
| 1102 | |||
| 1103 | /* | ||
| 1104 | ** structure to chain all variables in the left-hand side of an | ||
| 1105 | ** assignment | ||
| 1106 | */ | ||
| 1107 | struct LHS_assign { | ||
| 1108 | struct LHS_assign *prev; | ||
| 1109 | expdesc v; /* variable (global, local, upvalue, or indexed) */ | ||
| 1110 | }; | ||
| 1111 | |||
| 1112 | |||
| 1113 | /* | ||
| 1114 | ** check whether, in an assignment to an upvalue/local variable, the | ||
| 1115 | ** upvalue/local variable is begin used in a previous assignment to a | ||
| 1116 | ** table. If so, save original upvalue/local value in a safe place and | ||
| 1117 | ** use this safe copy in the previous assignment. | ||
| 1118 | */ | ||
| 1119 | static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { | ||
| 1120 | FuncState *fs = ls->fs; | ||
| 1121 | int extra = fs->freereg; /* eventual position to save local variable */ | ||
| 1122 | int conflict = 0; | ||
| 1123 | for (; lh; lh = lh->prev) { /* check all previous assignments */ | ||
| 1124 | if (lh->v.k == VINDEXED) { /* assigning to a table? */ | ||
| 1125 | /* table is the upvalue/local being assigned now? */ | ||
| 1126 | if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) { | ||
| 1127 | conflict = 1; | ||
| 1128 | lh->v.u.ind.vt = VLOCAL; | ||
| 1129 | lh->v.u.ind.t = extra; /* previous assignment will use safe copy */ | ||
| 1130 | } | ||
| 1131 | /* index is the local being assigned? (index cannot be upvalue) */ | ||
| 1132 | if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) { | ||
| 1133 | conflict = 1; | ||
| 1134 | lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */ | ||
| 1135 | } | ||
| 1136 | } | ||
| 1137 | } | ||
| 1138 | if (conflict) { | ||
| 1139 | /* copy upvalue/local value to a temporary (in position 'extra') */ | ||
| 1140 | OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; | ||
| 1141 | luaK_codeABC(fs, op, extra, v->u.info, 0); | ||
| 1142 | luaK_reserveregs(fs, 1); | ||
| 1143 | } | ||
| 1144 | } | ||
| 1145 | |||
| 1146 | |||
| 1147 | static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { | ||
| 1148 | expdesc e; | ||
| 1149 | check_condition(ls, vkisvar(lh->v.k), "syntax error"); | ||
| 1150 | if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */ | ||
| 1151 | struct LHS_assign nv; | ||
| 1152 | nv.prev = lh; | ||
| 1153 | suffixedexp(ls, &nv.v); | ||
| 1154 | if (nv.v.k != VINDEXED) | ||
| 1155 | check_conflict(ls, lh, &nv.v); | ||
| 1156 | checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS, | ||
| 1157 | "C levels"); | ||
| 1158 | assignment(ls, &nv, nvars+1); | ||
| 1159 | } | ||
| 1160 | else { /* assignment -> '=' explist */ | ||
| 1161 | int nexps; | ||
| 1162 | checknext(ls, '='); | ||
| 1163 | nexps = explist(ls, &e); | ||
| 1164 | if (nexps != nvars) | ||
| 1165 | adjust_assign(ls, nvars, nexps, &e); | ||
| 1166 | else { | ||
| 1167 | luaK_setoneret(ls->fs, &e); /* close last expression */ | ||
| 1168 | luaK_storevar(ls->fs, &lh->v, &e); | ||
| 1169 | return; /* avoid default */ | ||
| 1170 | } | ||
| 1171 | } | ||
| 1172 | init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ | ||
| 1173 | luaK_storevar(ls->fs, &lh->v, &e); | ||
| 1174 | } | ||
| 1175 | |||
| 1176 | |||
| 1177 | static int cond (LexState *ls) { | ||
| 1178 | /* cond -> exp */ | ||
| 1179 | expdesc v; | ||
| 1180 | expr(ls, &v); /* read condition */ | ||
| 1181 | if (v.k == VNIL) v.k = VFALSE; /* 'falses' are all equal here */ | ||
| 1182 | luaK_goiftrue(ls->fs, &v); | ||
| 1183 | return v.f; | ||
| 1184 | } | ||
| 1185 | |||
| 1186 | |||
| 1187 | static void gotostat (LexState *ls, int pc) { | ||
| 1188 | int line = ls->linenumber; | ||
| 1189 | TString *label; | ||
| 1190 | int g; | ||
| 1191 | if (testnext(ls, TK_GOTO)) | ||
| 1192 | label = str_checkname(ls); | ||
| 1193 | else { | ||
| 1194 | luaX_next(ls); /* skip break */ | ||
| 1195 | label = luaS_new(ls->L, "break"); | ||
| 1196 | } | ||
| 1197 | g = newlabelentry(ls, &ls->dyd->gt, label, line, pc); | ||
| 1198 | findlabel(ls, g); /* close it if label already defined */ | ||
| 1199 | } | ||
| 1200 | |||
| 1201 | |||
| 1202 | /* check for repeated labels on the same block */ | ||
| 1203 | static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) { | ||
| 1204 | int i; | ||
| 1205 | for (i = fs->bl->firstlabel; i < ll->n; i++) { | ||
| 1206 | if (eqstr(label, ll->arr[i].name)) { | ||
| 1207 | const char *msg = luaO_pushfstring(fs->ls->L, | ||
| 1208 | "label '%s' already defined on line %d", | ||
| 1209 | getstr(label), ll->arr[i].line); | ||
| 1210 | semerror(fs->ls, msg); | ||
| 1211 | } | ||
| 1212 | } | ||
| 1213 | } | ||
| 1214 | |||
| 1215 | |||
| 1216 | /* skip no-op statements */ | ||
| 1217 | static void skipnoopstat (LexState *ls) { | ||
| 1218 | while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) | ||
| 1219 | statement(ls); | ||
| 1220 | } | ||
| 1221 | |||
| 1222 | |||
| 1223 | static void labelstat (LexState *ls, TString *label, int line) { | ||
| 1224 | /* label -> '::' NAME '::' */ | ||
| 1225 | FuncState *fs = ls->fs; | ||
| 1226 | Labellist *ll = &ls->dyd->label; | ||
| 1227 | int l; /* index of new label being created */ | ||
| 1228 | checkrepeated(fs, ll, label); /* check for repeated labels */ | ||
| 1229 | checknext(ls, TK_DBCOLON); /* skip double colon */ | ||
| 1230 | /* create new entry for this label */ | ||
| 1231 | l = newlabelentry(ls, ll, label, line, luaK_getlabel(fs)); | ||
| 1232 | skipnoopstat(ls); /* skip other no-op statements */ | ||
| 1233 | if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */ | ||
| 1234 | /* assume that locals are already out of scope */ | ||
| 1235 | ll->arr[l].nactvar = fs->bl->nactvar; | ||
| 1236 | } | ||
| 1237 | findgotos(ls, &ll->arr[l]); | ||
| 1238 | } | ||
| 1239 | |||
| 1240 | |||
| 1241 | static void whilestat (LexState *ls, int line) { | ||
| 1242 | /* whilestat -> WHILE cond DO block END */ | ||
| 1243 | FuncState *fs = ls->fs; | ||
| 1244 | int whileinit; | ||
| 1245 | int condexit; | ||
| 1246 | BlockCnt bl; | ||
| 1247 | luaX_next(ls); /* skip WHILE */ | ||
| 1248 | whileinit = luaK_getlabel(fs); | ||
| 1249 | condexit = cond(ls); | ||
| 1250 | enterblock(fs, &bl, 1); | ||
| 1251 | checknext(ls, TK_DO); | ||
| 1252 | block(ls); | ||
| 1253 | luaK_jumpto(fs, whileinit); | ||
| 1254 | check_match(ls, TK_END, TK_WHILE, line); | ||
| 1255 | leaveblock(fs); | ||
| 1256 | luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ | ||
| 1257 | } | ||
| 1258 | |||
| 1259 | |||
| 1260 | static void repeatstat (LexState *ls, int line) { | ||
| 1261 | /* repeatstat -> REPEAT block UNTIL cond */ | ||
| 1262 | int condexit; | ||
| 1263 | FuncState *fs = ls->fs; | ||
| 1264 | int repeat_init = luaK_getlabel(fs); | ||
| 1265 | BlockCnt bl1, bl2; | ||
| 1266 | enterblock(fs, &bl1, 1); /* loop block */ | ||
| 1267 | enterblock(fs, &bl2, 0); /* scope block */ | ||
| 1268 | luaX_next(ls); /* skip REPEAT */ | ||
| 1269 | statlist(ls); | ||
| 1270 | check_match(ls, TK_UNTIL, TK_REPEAT, line); | ||
| 1271 | condexit = cond(ls); /* read condition (inside scope block) */ | ||
| 1272 | if (bl2.upval) /* upvalues? */ | ||
| 1273 | luaK_patchclose(fs, condexit, bl2.nactvar); | ||
| 1274 | leaveblock(fs); /* finish scope */ | ||
| 1275 | luaK_patchlist(fs, condexit, repeat_init); /* close the loop */ | ||
| 1276 | leaveblock(fs); /* finish loop */ | ||
| 1277 | } | ||
| 1278 | |||
| 1279 | |||
| 1280 | static int exp1 (LexState *ls) { | ||
| 1281 | expdesc e; | ||
| 1282 | int reg; | ||
| 1283 | expr(ls, &e); | ||
| 1284 | luaK_exp2nextreg(ls->fs, &e); | ||
| 1285 | lua_assert(e.k == VNONRELOC); | ||
| 1286 | reg = e.u.info; | ||
| 1287 | return reg; | ||
| 1288 | } | ||
| 1289 | |||
| 1290 | |||
| 1291 | static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { | ||
| 1292 | /* forbody -> DO block */ | ||
| 1293 | BlockCnt bl; | ||
| 1294 | FuncState *fs = ls->fs; | ||
| 1295 | int prep, endfor; | ||
| 1296 | adjustlocalvars(ls, 3); /* control variables */ | ||
| 1297 | checknext(ls, TK_DO); | ||
| 1298 | prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs); | ||
| 1299 | enterblock(fs, &bl, 0); /* scope for declared variables */ | ||
| 1300 | adjustlocalvars(ls, nvars); | ||
| 1301 | luaK_reserveregs(fs, nvars); | ||
| 1302 | block(ls); | ||
| 1303 | leaveblock(fs); /* end of scope for declared variables */ | ||
| 1304 | luaK_patchtohere(fs, prep); | ||
| 1305 | if (isnum) /* numeric for? */ | ||
| 1306 | endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP); | ||
| 1307 | else { /* generic for */ | ||
| 1308 | luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars); | ||
| 1309 | luaK_fixline(fs, line); | ||
| 1310 | endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP); | ||
| 1311 | } | ||
| 1312 | luaK_patchlist(fs, endfor, prep + 1); | ||
| 1313 | luaK_fixline(fs, line); | ||
| 1314 | } | ||
| 1315 | |||
| 1316 | |||
| 1317 | static void fornum (LexState *ls, TString *varname, int line) { | ||
| 1318 | /* fornum -> NAME = exp1,exp1[,exp1] forbody */ | ||
| 1319 | FuncState *fs = ls->fs; | ||
| 1320 | int base = fs->freereg; | ||
| 1321 | new_localvarliteral(ls, "(for index)"); | ||
| 1322 | new_localvarliteral(ls, "(for limit)"); | ||
| 1323 | new_localvarliteral(ls, "(for step)"); | ||
| 1324 | new_localvar(ls, varname); | ||
| 1325 | checknext(ls, '='); | ||
| 1326 | exp1(ls); /* initial value */ | ||
| 1327 | checknext(ls, ','); | ||
| 1328 | exp1(ls); /* limit */ | ||
| 1329 | if (testnext(ls, ',')) | ||
| 1330 | exp1(ls); /* optional step */ | ||
| 1331 | else { /* default step = 1 */ | ||
| 1332 | luaK_codek(fs, fs->freereg, luaK_intK(fs, 1)); | ||
| 1333 | luaK_reserveregs(fs, 1); | ||
| 1334 | } | ||
| 1335 | forbody(ls, base, line, 1, 1); | ||
| 1336 | } | ||
| 1337 | |||
| 1338 | |||
| 1339 | static void forlist (LexState *ls, TString *indexname) { | ||
| 1340 | /* forlist -> NAME {,NAME} IN explist forbody */ | ||
| 1341 | FuncState *fs = ls->fs; | ||
| 1342 | expdesc e; | ||
| 1343 | int nvars = 4; /* gen, state, control, plus at least one declared var */ | ||
| 1344 | int line; | ||
| 1345 | int base = fs->freereg; | ||
| 1346 | /* create control variables */ | ||
| 1347 | new_localvarliteral(ls, "(for generator)"); | ||
| 1348 | new_localvarliteral(ls, "(for state)"); | ||
| 1349 | new_localvarliteral(ls, "(for control)"); | ||
| 1350 | /* create declared variables */ | ||
| 1351 | new_localvar(ls, indexname); | ||
| 1352 | while (testnext(ls, ',')) { | ||
| 1353 | new_localvar(ls, str_checkname(ls)); | ||
| 1354 | nvars++; | ||
| 1355 | } | ||
| 1356 | checknext(ls, TK_IN); | ||
| 1357 | line = ls->linenumber; | ||
| 1358 | adjust_assign(ls, 3, explist(ls, &e), &e); | ||
| 1359 | luaK_checkstack(fs, 3); /* extra space to call generator */ | ||
| 1360 | forbody(ls, base, line, nvars - 3, 0); | ||
| 1361 | } | ||
| 1362 | |||
| 1363 | |||
| 1364 | static void forstat (LexState *ls, int line) { | ||
| 1365 | /* forstat -> FOR (fornum | forlist) END */ | ||
| 1366 | FuncState *fs = ls->fs; | ||
| 1367 | TString *varname; | ||
| 1368 | BlockCnt bl; | ||
| 1369 | enterblock(fs, &bl, 1); /* scope for loop and control variables */ | ||
| 1370 | luaX_next(ls); /* skip 'for' */ | ||
| 1371 | varname = str_checkname(ls); /* first variable name */ | ||
| 1372 | switch (ls->t.token) { | ||
| 1373 | case '=': fornum(ls, varname, line); break; | ||
| 1374 | case ',': case TK_IN: forlist(ls, varname); break; | ||
| 1375 | default: luaX_syntaxerror(ls, "'=' or 'in' expected"); | ||
| 1376 | } | ||
| 1377 | check_match(ls, TK_END, TK_FOR, line); | ||
| 1378 | leaveblock(fs); /* loop scope ('break' jumps to this point) */ | ||
| 1379 | } | ||
| 1380 | |||
| 1381 | |||
| 1382 | static void test_then_block (LexState *ls, int *escapelist) { | ||
| 1383 | /* test_then_block -> [IF | ELSEIF] cond THEN block */ | ||
| 1384 | BlockCnt bl; | ||
| 1385 | FuncState *fs = ls->fs; | ||
| 1386 | expdesc v; | ||
| 1387 | int jf; /* instruction to skip 'then' code (if condition is false) */ | ||
| 1388 | luaX_next(ls); /* skip IF or ELSEIF */ | ||
| 1389 | expr(ls, &v); /* read condition */ | ||
| 1390 | checknext(ls, TK_THEN); | ||
| 1391 | if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { | ||
| 1392 | luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ | ||
| 1393 | enterblock(fs, &bl, 0); /* must enter block before 'goto' */ | ||
| 1394 | gotostat(ls, v.t); /* handle goto/break */ | ||
| 1395 | while (testnext(ls, ';')) {} /* skip colons */ | ||
| 1396 | if (block_follow(ls, 0)) { /* 'goto' is the entire block? */ | ||
| 1397 | leaveblock(fs); | ||
| 1398 | return; /* and that is it */ | ||
| 1399 | } | ||
| 1400 | else /* must skip over 'then' part if condition is false */ | ||
| 1401 | jf = luaK_jump(fs); | ||
| 1402 | } | ||
| 1403 | else { /* regular case (not goto/break) */ | ||
| 1404 | luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ | ||
| 1405 | enterblock(fs, &bl, 0); | ||
| 1406 | jf = v.f; | ||
| 1407 | } | ||
| 1408 | statlist(ls); /* 'then' part */ | ||
| 1409 | leaveblock(fs); | ||
| 1410 | if (ls->t.token == TK_ELSE || | ||
| 1411 | ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ | ||
| 1412 | luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ | ||
| 1413 | luaK_patchtohere(fs, jf); | ||
| 1414 | } | ||
| 1415 | |||
| 1416 | |||
| 1417 | static void ifstat (LexState *ls, int line) { | ||
| 1418 | /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ | ||
| 1419 | FuncState *fs = ls->fs; | ||
| 1420 | int escapelist = NO_JUMP; /* exit list for finished parts */ | ||
| 1421 | test_then_block(ls, &escapelist); /* IF cond THEN block */ | ||
| 1422 | while (ls->t.token == TK_ELSEIF) | ||
| 1423 | test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */ | ||
| 1424 | if (testnext(ls, TK_ELSE)) | ||
| 1425 | block(ls); /* 'else' part */ | ||
| 1426 | check_match(ls, TK_END, TK_IF, line); | ||
| 1427 | luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ | ||
| 1428 | } | ||
| 1429 | |||
| 1430 | |||
| 1431 | static void localfunc (LexState *ls) { | ||
| 1432 | expdesc b; | ||
| 1433 | FuncState *fs = ls->fs; | ||
| 1434 | new_localvar(ls, str_checkname(ls)); /* new local variable */ | ||
| 1435 | adjustlocalvars(ls, 1); /* enter its scope */ | ||
| 1436 | body(ls, &b, 0, ls->linenumber); /* function created in next register */ | ||
| 1437 | /* debug information will only see the variable after this point! */ | ||
| 1438 | getlocvar(fs, b.u.info)->startpc = fs->pc; | ||
| 1439 | } | ||
| 1440 | |||
| 1441 | |||
| 1442 | static void localstat (LexState *ls) { | ||
| 1443 | /* stat -> LOCAL NAME {',' NAME} ['=' explist] */ | ||
| 1444 | int nvars = 0; | ||
| 1445 | int nexps; | ||
| 1446 | expdesc e; | ||
| 1447 | do { | ||
| 1448 | new_localvar(ls, str_checkname(ls)); | ||
| 1449 | nvars++; | ||
| 1450 | } while (testnext(ls, ',')); | ||
| 1451 | if (testnext(ls, '=')) | ||
| 1452 | nexps = explist(ls, &e); | ||
| 1453 | else { | ||
| 1454 | e.k = VVOID; | ||
| 1455 | nexps = 0; | ||
| 1456 | } | ||
| 1457 | adjust_assign(ls, nvars, nexps, &e); | ||
| 1458 | adjustlocalvars(ls, nvars); | ||
| 1459 | } | ||
| 1460 | |||
| 1461 | |||
| 1462 | static int funcname (LexState *ls, expdesc *v) { | ||
| 1463 | /* funcname -> NAME {fieldsel} [':' NAME] */ | ||
| 1464 | int ismethod = 0; | ||
| 1465 | singlevar(ls, v); | ||
| 1466 | while (ls->t.token == '.') | ||
| 1467 | fieldsel(ls, v); | ||
| 1468 | if (ls->t.token == ':') { | ||
| 1469 | ismethod = 1; | ||
| 1470 | fieldsel(ls, v); | ||
| 1471 | } | ||
| 1472 | return ismethod; | ||
| 1473 | } | ||
| 1474 | |||
| 1475 | |||
| 1476 | static void funcstat (LexState *ls, int line) { | ||
| 1477 | /* funcstat -> FUNCTION funcname body */ | ||
| 1478 | int ismethod; | ||
| 1479 | expdesc v, b; | ||
| 1480 | luaX_next(ls); /* skip FUNCTION */ | ||
| 1481 | ismethod = funcname(ls, &v); | ||
| 1482 | body(ls, &b, ismethod, line); | ||
| 1483 | luaK_storevar(ls->fs, &v, &b); | ||
| 1484 | luaK_fixline(ls->fs, line); /* definition "happens" in the first line */ | ||
| 1485 | } | ||
| 1486 | |||
| 1487 | |||
| 1488 | static void exprstat (LexState *ls) { | ||
| 1489 | /* stat -> func | assignment */ | ||
| 1490 | FuncState *fs = ls->fs; | ||
| 1491 | struct LHS_assign v; | ||
| 1492 | suffixedexp(ls, &v.v); | ||
| 1493 | if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */ | ||
| 1494 | v.prev = NULL; | ||
| 1495 | assignment(ls, &v, 1); | ||
| 1496 | } | ||
| 1497 | else { /* stat -> func */ | ||
| 1498 | check_condition(ls, v.v.k == VCALL, "syntax error"); | ||
| 1499 | SETARG_C(getinstruction(fs, &v.v), 1); /* call statement uses no results */ | ||
| 1500 | } | ||
| 1501 | } | ||
| 1502 | |||
| 1503 | |||
| 1504 | static void retstat (LexState *ls) { | ||
| 1505 | /* stat -> RETURN [explist] [';'] */ | ||
| 1506 | FuncState *fs = ls->fs; | ||
| 1507 | expdesc e; | ||
| 1508 | int first, nret; /* registers with returned values */ | ||
| 1509 | if (block_follow(ls, 1) || ls->t.token == ';') | ||
| 1510 | first = nret = 0; /* return no values */ | ||
| 1511 | else { | ||
| 1512 | nret = explist(ls, &e); /* optional return values */ | ||
| 1513 | if (hasmultret(e.k)) { | ||
| 1514 | luaK_setmultret(fs, &e); | ||
| 1515 | if (e.k == VCALL && nret == 1) { /* tail call? */ | ||
| 1516 | SET_OPCODE(getinstruction(fs,&e), OP_TAILCALL); | ||
| 1517 | lua_assert(GETARG_A(getinstruction(fs,&e)) == fs->nactvar); | ||
| 1518 | } | ||
| 1519 | first = fs->nactvar; | ||
| 1520 | nret = LUA_MULTRET; /* return all values */ | ||
| 1521 | } | ||
| 1522 | else { | ||
| 1523 | if (nret == 1) /* only one single value? */ | ||
| 1524 | first = luaK_exp2anyreg(fs, &e); | ||
| 1525 | else { | ||
| 1526 | luaK_exp2nextreg(fs, &e); /* values must go to the stack */ | ||
| 1527 | first = fs->nactvar; /* return all active values */ | ||
| 1528 | lua_assert(nret == fs->freereg - first); | ||
| 1529 | } | ||
| 1530 | } | ||
| 1531 | } | ||
| 1532 | luaK_ret(fs, first, nret); | ||
| 1533 | testnext(ls, ';'); /* skip optional semicolon */ | ||
| 1534 | } | ||
| 1535 | |||
| 1536 | |||
| 1537 | static void statement (LexState *ls) { | ||
| 1538 | int line = ls->linenumber; /* may be needed for error messages */ | ||
| 1539 | enterlevel(ls); | ||
| 1540 | switch (ls->t.token) { | ||
| 1541 | case ';': { /* stat -> ';' (empty statement) */ | ||
| 1542 | luaX_next(ls); /* skip ';' */ | ||
| 1543 | break; | ||
| 1544 | } | ||
| 1545 | case TK_IF: { /* stat -> ifstat */ | ||
| 1546 | ifstat(ls, line); | ||
| 1547 | break; | ||
| 1548 | } | ||
| 1549 | case TK_WHILE: { /* stat -> whilestat */ | ||
| 1550 | whilestat(ls, line); | ||
| 1551 | break; | ||
| 1552 | } | ||
| 1553 | case TK_DO: { /* stat -> DO block END */ | ||
| 1554 | luaX_next(ls); /* skip DO */ | ||
| 1555 | block(ls); | ||
| 1556 | check_match(ls, TK_END, TK_DO, line); | ||
| 1557 | break; | ||
| 1558 | } | ||
| 1559 | case TK_FOR: { /* stat -> forstat */ | ||
| 1560 | forstat(ls, line); | ||
| 1561 | break; | ||
| 1562 | } | ||
| 1563 | case TK_REPEAT: { /* stat -> repeatstat */ | ||
| 1564 | repeatstat(ls, line); | ||
| 1565 | break; | ||
| 1566 | } | ||
| 1567 | case TK_FUNCTION: { /* stat -> funcstat */ | ||
| 1568 | funcstat(ls, line); | ||
| 1569 | break; | ||
| 1570 | } | ||
| 1571 | case TK_LOCAL: { /* stat -> localstat */ | ||
| 1572 | luaX_next(ls); /* skip LOCAL */ | ||
| 1573 | if (testnext(ls, TK_FUNCTION)) /* local function? */ | ||
| 1574 | localfunc(ls); | ||
| 1575 | else | ||
| 1576 | localstat(ls); | ||
| 1577 | break; | ||
| 1578 | } | ||
| 1579 | case TK_DBCOLON: { /* stat -> label */ | ||
| 1580 | luaX_next(ls); /* skip double colon */ | ||
| 1581 | labelstat(ls, str_checkname(ls), line); | ||
| 1582 | break; | ||
| 1583 | } | ||
| 1584 | case TK_RETURN: { /* stat -> retstat */ | ||
| 1585 | luaX_next(ls); /* skip RETURN */ | ||
| 1586 | retstat(ls); | ||
| 1587 | break; | ||
| 1588 | } | ||
| 1589 | case TK_BREAK: /* stat -> breakstat */ | ||
| 1590 | case TK_GOTO: { /* stat -> 'goto' NAME */ | ||
| 1591 | gotostat(ls, luaK_jump(ls->fs)); | ||
| 1592 | break; | ||
| 1593 | } | ||
| 1594 | default: { /* stat -> func | assignment */ | ||
| 1595 | exprstat(ls); | ||
| 1596 | break; | ||
| 1597 | } | ||
| 1598 | } | ||
| 1599 | lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && | ||
| 1600 | ls->fs->freereg >= ls->fs->nactvar); | ||
| 1601 | ls->fs->freereg = ls->fs->nactvar; /* free registers */ | ||
| 1602 | leavelevel(ls); | ||
| 1603 | } | ||
| 1604 | |||
| 1605 | /* }====================================================================== */ | ||
| 1606 | |||
| 1607 | |||
| 1608 | /* | ||
| 1609 | ** compiles the main function, which is a regular vararg function with an | ||
| 1610 | ** upvalue named LUA_ENV | ||
| 1611 | */ | ||
| 1612 | static void mainfunc (LexState *ls, FuncState *fs) { | ||
| 1613 | BlockCnt bl; | ||
| 1614 | expdesc v; | ||
| 1615 | open_func(ls, fs, &bl); | ||
| 1616 | fs->f->is_vararg = 1; /* main function is always declared vararg */ | ||
| 1617 | init_exp(&v, VLOCAL, 0); /* create and... */ | ||
| 1618 | newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */ | ||
| 1619 | luaX_next(ls); /* read first token */ | ||
| 1620 | statlist(ls); /* parse main body */ | ||
| 1621 | check(ls, TK_EOS); | ||
| 1622 | close_func(ls); | ||
| 1623 | } | ||
| 1624 | |||
| 1625 | |||
| 1626 | LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, | ||
| 1627 | Dyndata *dyd, const char *name, int firstchar) { | ||
| 1628 | LexState lexstate; | ||
| 1629 | FuncState funcstate; | ||
| 1630 | LClosure *cl = luaF_newLclosure(L, 1); /* create main closure */ | ||
| 1631 | setclLvalue(L, L->top, cl); /* anchor it (to avoid being collected) */ | ||
| 1632 | luaD_inctop(L); | ||
| 1633 | lexstate.h = luaH_new(L); /* create table for scanner */ | ||
| 1634 | sethvalue(L, L->top, lexstate.h); /* anchor it */ | ||
| 1635 | luaD_inctop(L); | ||
| 1636 | funcstate.f = cl->p = luaF_newproto(L); | ||
| 1637 | funcstate.f->source = luaS_new(L, name); /* create and anchor TString */ | ||
| 1638 | lua_assert(iswhite(funcstate.f)); /* do not need barrier here */ | ||
| 1639 | lexstate.buff = buff; | ||
| 1640 | lexstate.dyd = dyd; | ||
| 1641 | dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; | ||
| 1642 | luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar); | ||
| 1643 | mainfunc(&lexstate, &funcstate); | ||
| 1644 | lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs); | ||
| 1645 | /* all scopes should be correctly finished */ | ||
| 1646 | lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0); | ||
| 1647 | L->top--; /* remove scanner's table */ | ||
| 1648 | return cl; /* closure is on the stack, too */ | ||
| 1649 | } | ||
| 1650 | |||
