diff options
Diffstat (limited to 'lib/lua/src/lparser.c')
| -rw-r--r-- | lib/lua/src/lparser.c | 1338 |
1 files changed, 0 insertions, 1338 deletions
diff --git a/lib/lua/src/lparser.c b/lib/lua/src/lparser.c deleted file mode 100644 index 688e6bc..0000000 --- a/lib/lua/src/lparser.c +++ /dev/null @@ -1,1338 +0,0 @@ -/* -** Lua Parser -** See Copyright Notice in lua.h -*/ - - -#include <string.h> - -#define lparser_c -#define LUA_CORE - -#include "lua.h" - -#include "lcode.h" -#include "ldebug.h" -#include "ldo.h" -#include "lfunc.h" -#include "llex.h" -#include "lmem.h" -#include "lobject.h" -#include "lopcodes.h" -#include "lparser.h" -#include "lstate.h" -#include "lstring.h" -#include "ltable.h" - - - -#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) - -#define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]]) - -#define luaY_checklimit(fs,v,l,m) if ((v)>(l)) errorlimit(fs,l,m) - - -/* -** nodes for block list (list of active blocks) -*/ -typedef struct BlockCnt { - struct BlockCnt *previous; /* chain */ - int breaklist; /* list of jumps out of this loop */ - lu_byte nactvar; /* # active locals outside the breakable structure */ - lu_byte upval; /* true if some variable in the block is an upvalue */ - lu_byte isbreakable; /* true if `block' is a loop */ -} BlockCnt; - - - -/* -** prototypes for recursive non-terminal functions -*/ -static void chunk (LexState *ls); -static void expr (LexState *ls, expdesc *v); - - -static void anchor_token (LexState *ls) { - if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) { - TString *ts = ls->t.seminfo.ts; - luaX_newstring(ls, getstr(ts), ts->tsv.len); - } -} - - -static void error_expected (LexState *ls, int token) { - luaX_syntaxerror(ls, - luaO_pushfstring(ls->L, LUA_QS " expected", luaX_token2str(ls, token))); -} - - -static void errorlimit (FuncState *fs, int limit, const char *what) { - const char *msg = (fs->f->linedefined == 0) ? - luaO_pushfstring(fs->L, "main function has more than %d %s", limit, what) : - luaO_pushfstring(fs->L, "function at line %d has more than %d %s", - fs->f->linedefined, limit, what); - luaX_lexerror(fs->ls, msg, 0); -} - - -static int testnext (LexState *ls, int c) { - if (ls->t.token == c) { - luaX_next(ls); - return 1; - } - else return 0; -} - - -static void check (LexState *ls, int c) { - if (ls->t.token != c) - error_expected(ls, c); -} - -static void checknext (LexState *ls, int c) { - check(ls, c); - luaX_next(ls); -} - - -#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } - - - -static void check_match (LexState *ls, int what, int who, int where) { - if (!testnext(ls, what)) { - if (where == ls->linenumber) - error_expected(ls, what); - else { - luaX_syntaxerror(ls, luaO_pushfstring(ls->L, - LUA_QS " expected (to close " LUA_QS " at line %d)", - luaX_token2str(ls, what), luaX_token2str(ls, who), where)); - } - } -} - - -static TString *str_checkname (LexState *ls) { - TString *ts; - check(ls, TK_NAME); - ts = ls->t.seminfo.ts; - luaX_next(ls); - return ts; -} - - -static void init_exp (expdesc *e, expkind k, int i) { - e->f = e->t = NO_JUMP; - e->k = k; - e->u.s.info = i; -} - - -static void codestring (LexState *ls, expdesc *e, TString *s) { - init_exp(e, VK, luaK_stringK(ls->fs, s)); -} - - -static void checkname(LexState *ls, expdesc *e) { - codestring(ls, e, str_checkname(ls)); -} - - -static int registerlocalvar (LexState *ls, TString *varname) { - FuncState *fs = ls->fs; - Proto *f = fs->f; - int oldsize = f->sizelocvars; - luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, - LocVar, SHRT_MAX, "too many local variables"); - while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL; - f->locvars[fs->nlocvars].varname = varname; - luaC_objbarrier(ls->L, f, varname); - return fs->nlocvars++; -} - - -#define new_localvarliteral(ls,v,n) \ - new_localvar(ls, luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char))-1), n) - - -static void new_localvar (LexState *ls, TString *name, int n) { - FuncState *fs = ls->fs; - luaY_checklimit(fs, fs->nactvar+n+1, LUAI_MAXVARS, "local variables"); - fs->actvar[fs->nactvar+n] = cast(unsigned short, registerlocalvar(ls, name)); -} - - -static void adjustlocalvars (LexState *ls, int nvars) { - FuncState *fs = ls->fs; - fs->nactvar = cast_byte(fs->nactvar + nvars); - for (; nvars; nvars--) { - getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc; - } -} - - -static void removevars (LexState *ls, int tolevel) { - FuncState *fs = ls->fs; - while (fs->nactvar > tolevel) - getlocvar(fs, --fs->nactvar).endpc = fs->pc; -} - - -static int indexupvalue (FuncState *fs, TString *name, expdesc *v) { - int i; - Proto *f = fs->f; - int oldsize = f->sizeupvalues; - for (i=0; i<f->nups; i++) { - if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) { - lua_assert(f->upvalues[i] == name); - return i; - } - } - /* new one */ - luaY_checklimit(fs, f->nups + 1, LUAI_MAXUPVALUES, "upvalues"); - luaM_growvector(fs->L, f->upvalues, f->nups, f->sizeupvalues, - TString *, MAX_INT, ""); - while (oldsize < f->sizeupvalues) f->upvalues[oldsize++] = NULL; - f->upvalues[f->nups] = name; - luaC_objbarrier(fs->L, f, name); - lua_assert(v->k == VLOCAL || v->k == VUPVAL); - fs->upvalues[f->nups].k = cast_byte(v->k); - fs->upvalues[f->nups].info = cast_byte(v->u.s.info); - return f->nups++; -} - - -static int searchvar (FuncState *fs, TString *n) { - int i; - for (i=fs->nactvar-1; i >= 0; i--) { - if (n == getlocvar(fs, i).varname) - return i; - } - return -1; /* not found */ -} - - -static void markupval (FuncState *fs, int level) { - BlockCnt *bl = fs->bl; - while (bl && bl->nactvar > level) bl = bl->previous; - if (bl) bl->upval = 1; -} - - -static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { - if (fs == NULL) { /* no more levels? */ - init_exp(var, VGLOBAL, NO_REG); /* default is global variable */ - return VGLOBAL; - } - else { - int v = searchvar(fs, n); /* look up at current level */ - if (v >= 0) { - init_exp(var, VLOCAL, v); - if (!base) - markupval(fs, v); /* local will be used as an upval */ - return VLOCAL; - } - else { /* not found at current level; try upper one */ - if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL) - return VGLOBAL; - var->u.s.info = indexupvalue(fs, n, var); /* else was LOCAL or UPVAL */ - var->k = VUPVAL; /* upvalue in this level */ - return VUPVAL; - } - } -} - - -static void singlevar (LexState *ls, expdesc *var) { - TString *varname = str_checkname(ls); - FuncState *fs = ls->fs; - if (singlevaraux(fs, varname, var, 1) == VGLOBAL) - var->u.s.info = luaK_stringK(fs, varname); /* info points to global name */ -} - - -static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { - FuncState *fs = ls->fs; - int extra = nvars - nexps; - if (hasmultret(e->k)) { - extra++; /* includes call itself */ - if (extra < 0) extra = 0; - luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ - if (extra > 1) luaK_reserveregs(fs, extra-1); - } - else { - if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ - if (extra > 0) { - int reg = fs->freereg; - luaK_reserveregs(fs, extra); - luaK_nil(fs, reg, extra); - } - } -} - - -static void enterlevel (LexState *ls) { - if (++ls->L->nCcalls > LUAI_MAXCCALLS) - luaX_lexerror(ls, "chunk has too many syntax levels", 0); -} - - -#define leavelevel(ls) ((ls)->L->nCcalls--) - - -static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) { - bl->breaklist = NO_JUMP; - bl->isbreakable = isbreakable; - bl->nactvar = fs->nactvar; - bl->upval = 0; - bl->previous = fs->bl; - fs->bl = bl; - lua_assert(fs->freereg == fs->nactvar); -} - - -static void leaveblock (FuncState *fs) { - BlockCnt *bl = fs->bl; - fs->bl = bl->previous; - removevars(fs->ls, bl->nactvar); - if (bl->upval) - luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); - /* a block either controls scope or breaks (never both) */ - lua_assert(!bl->isbreakable || !bl->upval); - lua_assert(bl->nactvar == fs->nactvar); - fs->freereg = fs->nactvar; /* free registers */ - luaK_patchtohere(fs, bl->breaklist); -} - - -static void pushclosure (LexState *ls, FuncState *func, expdesc *v) { - FuncState *fs = ls->fs; - Proto *f = fs->f; - int oldsize = f->sizep; - int i; - luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *, - MAXARG_Bx, "constant table overflow"); - while (oldsize < f->sizep) f->p[oldsize++] = NULL; - f->p[fs->np++] = func->f; - luaC_objbarrier(ls->L, f, func->f); - init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1)); - for (i=0; i<func->f->nups; i++) { - OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; - luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0); - } -} - - -static void open_func (LexState *ls, FuncState *fs) { - lua_State *L = ls->L; - Proto *f = luaF_newproto(L); - fs->f = f; - fs->prev = ls->fs; /* linked list of funcstates */ - fs->ls = ls; - fs->L = L; - ls->fs = fs; - fs->pc = 0; - fs->lasttarget = -1; - fs->jpc = NO_JUMP; - fs->freereg = 0; - fs->nk = 0; - fs->np = 0; - fs->nlocvars = 0; - fs->nactvar = 0; - fs->bl = NULL; - f->source = ls->source; - f->maxstacksize = 2; /* registers 0/1 are always valid */ - fs->h = luaH_new(L, 0, 0); - /* anchor table of constants and prototype (to avoid being collected) */ - sethvalue2s(L, L->top, fs->h); - incr_top(L); - setptvalue2s(L, L->top, f); - incr_top(L); -} - - -static void close_func (LexState *ls) { - lua_State *L = ls->L; - FuncState *fs = ls->fs; - Proto *f = fs->f; - removevars(ls, 0); - luaK_ret(fs, 0, 0); /* final return */ - luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); - f->sizecode = fs->pc; - luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); - f->sizelineinfo = fs->pc; - luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue); - f->sizek = fs->nk; - luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); - f->sizep = fs->np; - luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); - f->sizelocvars = fs->nlocvars; - luaM_reallocvector(L, f->upvalues, f->sizeupvalues, f->nups, TString *); - f->sizeupvalues = f->nups; - lua_assert(luaG_checkcode(f)); - lua_assert(fs->bl == NULL); - ls->fs = fs->prev; - L->top -= 2; /* remove table and prototype from the stack */ - /* last token read was anchored in defunct function; must reanchor it */ - if (fs) anchor_token(ls); -} - - -Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, const char *name) { - struct LexState lexstate; - struct FuncState funcstate; - lexstate.buff = buff; - luaX_setinput(L, &lexstate, z, luaS_new(L, name)); - open_func(&lexstate, &funcstate); - funcstate.f->is_vararg = VARARG_ISVARARG; /* main func. is always vararg */ - luaX_next(&lexstate); /* read first token */ - chunk(&lexstate); - check(&lexstate, TK_EOS); - close_func(&lexstate); - lua_assert(funcstate.prev == NULL); - lua_assert(funcstate.f->nups == 0); - lua_assert(lexstate.fs == NULL); - return funcstate.f; -} - - - -/*============================================================*/ -/* GRAMMAR RULES */ -/*============================================================*/ - - -static void field (LexState *ls, expdesc *v) { - /* field -> ['.' | ':'] NAME */ - FuncState *fs = ls->fs; - expdesc key; - luaK_exp2anyreg(fs, v); - luaX_next(ls); /* skip the dot or colon */ - checkname(ls, &key); - luaK_indexed(fs, v, &key); -} - - -static void yindex (LexState *ls, expdesc *v) { - /* index -> '[' expr ']' */ - luaX_next(ls); /* skip the '[' */ - expr(ls, v); - luaK_exp2val(ls->fs, v); - checknext(ls, ']'); -} - - -/* -** {====================================================================== -** Rules for Constructors -** ======================================================================= -*/ - - -struct ConsControl { - expdesc v; /* last list item read */ - expdesc *t; /* table descriptor */ - int nh; /* total number of `record' elements */ - int na; /* total number of array elements */ - int tostore; /* number of array elements pending to be stored */ -}; - - -static void recfield (LexState *ls, struct ConsControl *cc) { - /* recfield -> (NAME | `['exp1`]') = exp1 */ - FuncState *fs = ls->fs; - int reg = ls->fs->freereg; - expdesc key, val; - int rkkey; - if (ls->t.token == TK_NAME) { - luaY_checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); - checkname(ls, &key); - } - else /* ls->t.token == '[' */ - yindex(ls, &key); - cc->nh++; - checknext(ls, '='); - rkkey = luaK_exp2RK(fs, &key); - expr(ls, &val); - luaK_codeABC(fs, OP_SETTABLE, cc->t->u.s.info, rkkey, luaK_exp2RK(fs, &val)); - fs->freereg = reg; /* free registers */ -} - - -static void closelistfield (FuncState *fs, struct ConsControl *cc) { - if (cc->v.k == VVOID) return; /* there is no list item */ - luaK_exp2nextreg(fs, &cc->v); - cc->v.k = VVOID; - if (cc->tostore == LFIELDS_PER_FLUSH) { - luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore); /* flush */ - cc->tostore = 0; /* no more items pending */ - } -} - - -static void lastlistfield (FuncState *fs, struct ConsControl *cc) { - if (cc->tostore == 0) return; - if (hasmultret(cc->v.k)) { - luaK_setmultret(fs, &cc->v); - luaK_setlist(fs, cc->t->u.s.info, cc->na, LUA_MULTRET); - cc->na--; /* do not count last expression (unknown number of elements) */ - } - else { - if (cc->v.k != VVOID) - luaK_exp2nextreg(fs, &cc->v); - luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore); - } -} - - -static void listfield (LexState *ls, struct ConsControl *cc) { - expr(ls, &cc->v); - luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); - cc->na++; - cc->tostore++; -} - - -static void constructor (LexState *ls, expdesc *t) { - /* constructor -> ?? */ - FuncState *fs = ls->fs; - int line = ls->linenumber; - int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); - struct ConsControl cc; - cc.na = cc.nh = cc.tostore = 0; - cc.t = t; - init_exp(t, VRELOCABLE, pc); - init_exp(&cc.v, VVOID, 0); /* no value (yet) */ - luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */ - checknext(ls, '{'); - do { - lua_assert(cc.v.k == VVOID || cc.tostore > 0); - if (ls->t.token == '}') break; - closelistfield(fs, &cc); - switch(ls->t.token) { - case TK_NAME: { /* may be listfields or recfields */ - luaX_lookahead(ls); - if (ls->lookahead.token != '=') /* expression? */ - listfield(ls, &cc); - else - recfield(ls, &cc); - break; - } - case '[': { /* constructor_item -> recfield */ - recfield(ls, &cc); - break; - } - default: { /* constructor_part -> listfield */ - listfield(ls, &cc); - break; - } - } - } while (testnext(ls, ',') || testnext(ls, ';')); - check_match(ls, '}', '{', line); - lastlistfield(fs, &cc); - SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ - SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */ -} - -/* }====================================================================== */ - - - -static void parlist (LexState *ls) { - /* parlist -> [ param { `,' param } ] */ - FuncState *fs = ls->fs; - Proto *f = fs->f; - int nparams = 0; - f->is_vararg = 0; - if (ls->t.token != ')') { /* is `parlist' not empty? */ - do { - switch (ls->t.token) { - case TK_NAME: { /* param -> NAME */ - new_localvar(ls, str_checkname(ls), nparams++); - break; - } - case TK_DOTS: { /* param -> `...' */ - luaX_next(ls); -#if defined(LUA_COMPAT_VARARG) - /* use `arg' as default name */ - new_localvarliteral(ls, "arg", nparams++); - f->is_vararg = VARARG_HASARG | VARARG_NEEDSARG; -#endif - f->is_vararg |= VARARG_ISVARARG; - break; - } - default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected"); - } - } while (!f->is_vararg && testnext(ls, ',')); - } - adjustlocalvars(ls, nparams); - f->numparams = cast_byte(fs->nactvar - (f->is_vararg & VARARG_HASARG)); - luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ -} - - -static void body (LexState *ls, expdesc *e, int needself, int line) { - /* body -> `(' parlist `)' chunk END */ - FuncState new_fs; - open_func(ls, &new_fs); - new_fs.f->linedefined = line; - checknext(ls, '('); - if (needself) { - new_localvarliteral(ls, "self", 0); - adjustlocalvars(ls, 1); - } - parlist(ls); - checknext(ls, ')'); - chunk(ls); - new_fs.f->lastlinedefined = ls->linenumber; - check_match(ls, TK_END, TK_FUNCTION, line); - close_func(ls); - pushclosure(ls, &new_fs, e); -} - - -static int explist1 (LexState *ls, expdesc *v) { - /* explist1 -> expr { `,' expr } */ - int n = 1; /* at least one expression */ - expr(ls, v); - while (testnext(ls, ',')) { - luaK_exp2nextreg(ls->fs, v); - expr(ls, v); - n++; - } - return n; -} - - -static void funcargs (LexState *ls, expdesc *f) { - FuncState *fs = ls->fs; - expdesc args; - int base, nparams; - int line = ls->linenumber; - switch (ls->t.token) { - case '(': { /* funcargs -> `(' [ explist1 ] `)' */ - if (line != ls->lastline) - luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)"); - luaX_next(ls); - if (ls->t.token == ')') /* arg list is empty? */ - args.k = VVOID; - else { - explist1(ls, &args); - luaK_setmultret(fs, &args); - } - check_match(ls, ')', '(', line); - break; - } - case '{': { /* funcargs -> constructor */ - constructor(ls, &args); - break; - } - case TK_STRING: { /* funcargs -> STRING */ - codestring(ls, &args, ls->t.seminfo.ts); - luaX_next(ls); /* must use `seminfo' before `next' */ - break; - } - default: { - luaX_syntaxerror(ls, "function arguments expected"); - return; - } - } - lua_assert(f->k == VNONRELOC); - base = f->u.s.info; /* base register for call */ - if (hasmultret(args.k)) - nparams = LUA_MULTRET; /* open call */ - else { - if (args.k != VVOID) - luaK_exp2nextreg(fs, &args); /* close last argument */ - nparams = fs->freereg - (base+1); - } - init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); - luaK_fixline(fs, line); - fs->freereg = base+1; /* call remove function and arguments and leaves - (unless changed) one result */ -} - - - - -/* -** {====================================================================== -** Expression parsing -** ======================================================================= -*/ - - -static void prefixexp (LexState *ls, expdesc *v) { - /* prefixexp -> NAME | '(' expr ')' */ - switch (ls->t.token) { - case '(': { - int line = ls->linenumber; - luaX_next(ls); - expr(ls, v); - check_match(ls, ')', '(', line); - luaK_dischargevars(ls->fs, v); - return; - } - case TK_NAME: { - singlevar(ls, v); - return; - } - default: { - luaX_syntaxerror(ls, "unexpected symbol"); - return; - } - } -} - - -static void primaryexp (LexState *ls, expdesc *v) { - /* primaryexp -> - prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */ - FuncState *fs = ls->fs; - prefixexp(ls, v); - for (;;) { - switch (ls->t.token) { - case '.': { /* field */ - field(ls, v); - break; - } - case '[': { /* `[' exp1 `]' */ - expdesc key; - luaK_exp2anyreg(fs, v); - yindex(ls, &key); - luaK_indexed(fs, v, &key); - break; - } - case ':': { /* `:' NAME funcargs */ - expdesc key; - luaX_next(ls); - checkname(ls, &key); - luaK_self(fs, v, &key); - funcargs(ls, v); - break; - } - case '(': case TK_STRING: case '{': { /* funcargs */ - luaK_exp2nextreg(fs, v); - funcargs(ls, v); - break; - } - default: return; - } - } -} - - -static void simpleexp (LexState *ls, expdesc *v) { - /* simpleexp -> NUMBER | STRING | NIL | true | false | ... | - constructor | FUNCTION body | primaryexp */ - switch (ls->t.token) { - case TK_NUMBER: { - init_exp(v, VKNUM, 0); - v->u.nval = ls->t.seminfo.r; - break; - } - case TK_STRING: { - codestring(ls, v, ls->t.seminfo.ts); - break; - } - case TK_NIL: { - init_exp(v, VNIL, 0); - break; - } - case TK_TRUE: { - init_exp(v, VTRUE, 0); - break; - } - case TK_FALSE: { - init_exp(v, VFALSE, 0); - break; - } - case TK_DOTS: { /* vararg */ - FuncState *fs = ls->fs; - check_condition(ls, fs->f->is_vararg, - "cannot use " LUA_QL("...") " outside a vararg function"); - fs->f->is_vararg &= ~VARARG_NEEDSARG; /* don't need 'arg' */ - init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0)); - break; - } - case '{': { /* constructor */ - constructor(ls, v); - return; - } - case TK_FUNCTION: { - luaX_next(ls); - body(ls, v, 0, ls->linenumber); - return; - } - default: { - primaryexp(ls, v); - return; - } - } - luaX_next(ls); -} - - -static UnOpr getunopr (int op) { - switch (op) { - case TK_NOT: return OPR_NOT; - case '-': return OPR_MINUS; - case '#': return OPR_LEN; - default: return OPR_NOUNOPR; - } -} - - -static BinOpr getbinopr (int op) { - switch (op) { - case '+': return OPR_ADD; - case '-': return OPR_SUB; - case '*': return OPR_MUL; - case '/': return OPR_DIV; - case '%': return OPR_MOD; - case '^': return OPR_POW; - case TK_CONCAT: return OPR_CONCAT; - case TK_NE: return OPR_NE; - case TK_EQ: return OPR_EQ; - case '<': return OPR_LT; - case TK_LE: return OPR_LE; - case '>': return OPR_GT; - case TK_GE: return OPR_GE; - case TK_AND: return OPR_AND; - case TK_OR: return OPR_OR; - default: return OPR_NOBINOPR; - } -} - - -static const struct { - lu_byte left; /* left priority for each binary operator */ - lu_byte right; /* right priority */ -} priority[] = { /* ORDER OPR */ - {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `/' `%' */ - {10, 9}, {5, 4}, /* power and concat (right associative) */ - {3, 3}, {3, 3}, /* equality and inequality */ - {3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */ - {2, 2}, {1, 1} /* logical (and/or) */ -}; - -#define UNARY_PRIORITY 8 /* priority for unary operators */ - - -/* -** subexpr -> (simpleexp | unop subexpr) { binop subexpr } -** where `binop' is any binary operator with a priority higher than `limit' -*/ -static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) { - BinOpr op; - UnOpr uop; - enterlevel(ls); - uop = getunopr(ls->t.token); - if (uop != OPR_NOUNOPR) { - luaX_next(ls); - subexpr(ls, v, UNARY_PRIORITY); - luaK_prefix(ls->fs, uop, v); - } - else simpleexp(ls, v); - /* expand while operators have priorities higher than `limit' */ - op = getbinopr(ls->t.token); - while (op != OPR_NOBINOPR && priority[op].left > limit) { - expdesc v2; - BinOpr nextop; - luaX_next(ls); - luaK_infix(ls->fs, op, v); - /* read sub-expression with higher priority */ - nextop = subexpr(ls, &v2, priority[op].right); - luaK_posfix(ls->fs, op, v, &v2); - op = nextop; - } - leavelevel(ls); - return op; /* return first untreated operator */ -} - - -static void expr (LexState *ls, expdesc *v) { - subexpr(ls, v, 0); -} - -/* }==================================================================== */ - - - -/* -** {====================================================================== -** Rules for Statements -** ======================================================================= -*/ - - -static int block_follow (int token) { - switch (token) { - case TK_ELSE: case TK_ELSEIF: case TK_END: - case TK_UNTIL: case TK_EOS: - return 1; - default: return 0; - } -} - - -static void block (LexState *ls) { - /* block -> chunk */ - FuncState *fs = ls->fs; - BlockCnt bl; - enterblock(fs, &bl, 0); - chunk(ls); - lua_assert(bl.breaklist == NO_JUMP); - leaveblock(fs); -} - - -/* -** structure to chain all variables in the left-hand side of an -** assignment -*/ -struct LHS_assign { - struct LHS_assign *prev; - expdesc v; /* variable (global, local, upvalue, or indexed) */ -}; - - -/* -** check whether, in an assignment to a local variable, the local variable -** is needed in a previous assignment (to a table). If so, save original -** local value in a safe place and use this safe copy in the previous -** assignment. -*/ -static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { - FuncState *fs = ls->fs; - int extra = fs->freereg; /* eventual position to save local variable */ - int conflict = 0; - for (; lh; lh = lh->prev) { - if (lh->v.k == VINDEXED) { - if (lh->v.u.s.info == v->u.s.info) { /* conflict? */ - conflict = 1; - lh->v.u.s.info = extra; /* previous assignment will use safe copy */ - } - if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */ - conflict = 1; - lh->v.u.s.aux = extra; /* previous assignment will use safe copy */ - } - } - } - if (conflict) { - luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.s.info, 0); /* make copy */ - luaK_reserveregs(fs, 1); - } -} - - -static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { - expdesc e; - check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED, - "syntax error"); - if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */ - struct LHS_assign nv; - nv.prev = lh; - primaryexp(ls, &nv.v); - if (nv.v.k == VLOCAL) - check_conflict(ls, lh, &nv.v); - luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls, - "variables in assignment"); - assignment(ls, &nv, nvars+1); - } - else { /* assignment -> `=' explist1 */ - int nexps; - checknext(ls, '='); - nexps = explist1(ls, &e); - if (nexps != nvars) { - adjust_assign(ls, nvars, nexps, &e); - if (nexps > nvars) - ls->fs->freereg -= nexps - nvars; /* remove extra values */ - } - else { - luaK_setoneret(ls->fs, &e); /* close last expression */ - luaK_storevar(ls->fs, &lh->v, &e); - return; /* avoid default */ - } - } - init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ - luaK_storevar(ls->fs, &lh->v, &e); -} - - -static int cond (LexState *ls) { - /* cond -> exp */ - expdesc v; - expr(ls, &v); /* read condition */ - if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */ - luaK_goiftrue(ls->fs, &v); - return v.f; -} - - -static void breakstat (LexState *ls) { - FuncState *fs = ls->fs; - BlockCnt *bl = fs->bl; - int upval = 0; - while (bl && !bl->isbreakable) { - upval |= bl->upval; - bl = bl->previous; - } - if (!bl) - luaX_syntaxerror(ls, "no loop to break"); - if (upval) - luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); - luaK_concat(fs, &bl->breaklist, luaK_jump(fs)); -} - - -static void whilestat (LexState *ls, int line) { - /* whilestat -> WHILE cond DO block END */ - FuncState *fs = ls->fs; - int whileinit; - int condexit; - BlockCnt bl; - luaX_next(ls); /* skip WHILE */ - whileinit = luaK_getlabel(fs); - condexit = cond(ls); - enterblock(fs, &bl, 1); - checknext(ls, TK_DO); - block(ls); - luaK_patchlist(fs, luaK_jump(fs), whileinit); - check_match(ls, TK_END, TK_WHILE, line); - leaveblock(fs); - luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ -} - - -static void repeatstat (LexState *ls, int line) { - /* repeatstat -> REPEAT block UNTIL cond */ - int condexit; - FuncState *fs = ls->fs; - int repeat_init = luaK_getlabel(fs); - BlockCnt bl1, bl2; - enterblock(fs, &bl1, 1); /* loop block */ - enterblock(fs, &bl2, 0); /* scope block */ - luaX_next(ls); /* skip REPEAT */ - chunk(ls); - check_match(ls, TK_UNTIL, TK_REPEAT, line); - condexit = cond(ls); /* read condition (inside scope block) */ - if (!bl2.upval) { /* no upvalues? */ - leaveblock(fs); /* finish scope */ - luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */ - } - else { /* complete semantics when there are upvalues */ - breakstat(ls); /* if condition then break */ - luaK_patchtohere(ls->fs, condexit); /* else... */ - leaveblock(fs); /* finish scope... */ - luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */ - } - leaveblock(fs); /* finish loop */ -} - - -static int exp1 (LexState *ls) { - expdesc e; - int k; - expr(ls, &e); - k = e.k; - luaK_exp2nextreg(ls->fs, &e); - return k; -} - - -static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { - /* forbody -> DO block */ - BlockCnt bl; - FuncState *fs = ls->fs; - int prep, endfor; - adjustlocalvars(ls, 3); /* control variables */ - checknext(ls, TK_DO); - prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs); - enterblock(fs, &bl, 0); /* scope for declared variables */ - adjustlocalvars(ls, nvars); - luaK_reserveregs(fs, nvars); - block(ls); - leaveblock(fs); /* end of scope for declared variables */ - luaK_patchtohere(fs, prep); - endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) : - luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars); - luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */ - luaK_patchlist(fs, (isnum ? endfor : luaK_jump(fs)), prep + 1); -} - - -static void fornum (LexState *ls, TString *varname, int line) { - /* fornum -> NAME = exp1,exp1[,exp1] forbody */ - FuncState *fs = ls->fs; - int base = fs->freereg; - new_localvarliteral(ls, "(for index)", 0); - new_localvarliteral(ls, "(for limit)", 1); - new_localvarliteral(ls, "(for step)", 2); - new_localvar(ls, varname, 3); - checknext(ls, '='); - exp1(ls); /* initial value */ - checknext(ls, ','); - exp1(ls); /* limit */ - if (testnext(ls, ',')) - exp1(ls); /* optional step */ - else { /* default step = 1 */ - luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1)); - luaK_reserveregs(fs, 1); - } - forbody(ls, base, line, 1, 1); -} - - -static void forlist (LexState *ls, TString *indexname) { - /* forlist -> NAME {,NAME} IN explist1 forbody */ - FuncState *fs = ls->fs; - expdesc e; - int nvars = 0; - int line; - int base = fs->freereg; - /* create control variables */ - new_localvarliteral(ls, "(for generator)", nvars++); - new_localvarliteral(ls, "(for state)", nvars++); - new_localvarliteral(ls, "(for control)", nvars++); - /* create declared variables */ - new_localvar(ls, indexname, nvars++); - while (testnext(ls, ',')) - new_localvar(ls, str_checkname(ls), nvars++); - checknext(ls, TK_IN); - line = ls->linenumber; - adjust_assign(ls, 3, explist1(ls, &e), &e); - luaK_checkstack(fs, 3); /* extra space to call generator */ - forbody(ls, base, line, nvars - 3, 0); -} - - -static void forstat (LexState *ls, int line) { - /* forstat -> FOR (fornum | forlist) END */ - FuncState *fs = ls->fs; - TString *varname; - BlockCnt bl; - enterblock(fs, &bl, 1); /* scope for loop and control variables */ - luaX_next(ls); /* skip `for' */ - varname = str_checkname(ls); /* first variable name */ - switch (ls->t.token) { - case '=': fornum(ls, varname, line); break; - case ',': case TK_IN: forlist(ls, varname); break; - default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected"); - } - check_match(ls, TK_END, TK_FOR, line); - leaveblock(fs); /* loop scope (`break' jumps to this point) */ -} - - -static int test_then_block (LexState *ls) { - /* test_then_block -> [IF | ELSEIF] cond THEN block */ - int condexit; - luaX_next(ls); /* skip IF or ELSEIF */ - condexit = cond(ls); - checknext(ls, TK_THEN); - block(ls); /* `then' part */ - return condexit; -} - - -static void ifstat (LexState *ls, int line) { - /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ - FuncState *fs = ls->fs; - int flist; - int escapelist = NO_JUMP; - flist = test_then_block(ls); /* IF cond THEN block */ - while (ls->t.token == TK_ELSEIF) { - luaK_concat(fs, &escapelist, luaK_jump(fs)); - luaK_patchtohere(fs, flist); - flist = test_then_block(ls); /* ELSEIF cond THEN block */ - } - if (ls->t.token == TK_ELSE) { - luaK_concat(fs, &escapelist, luaK_jump(fs)); - luaK_patchtohere(fs, flist); - luaX_next(ls); /* skip ELSE (after patch, for correct line info) */ - block(ls); /* `else' part */ - } - else - luaK_concat(fs, &escapelist, flist); - luaK_patchtohere(fs, escapelist); - check_match(ls, TK_END, TK_IF, line); -} - - -static void localfunc (LexState *ls) { - expdesc v, b; - FuncState *fs = ls->fs; - new_localvar(ls, str_checkname(ls), 0); - init_exp(&v, VLOCAL, fs->freereg); - luaK_reserveregs(fs, 1); - adjustlocalvars(ls, 1); - body(ls, &b, 0, ls->linenumber); - luaK_storevar(fs, &v, &b); - /* debug information will only see the variable after this point! */ - getlocvar(fs, fs->nactvar - 1).startpc = fs->pc; -} - - -static void localstat (LexState *ls) { - /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */ - int nvars = 0; - int nexps; - expdesc e; - do { - new_localvar(ls, str_checkname(ls), nvars++); - } while (testnext(ls, ',')); - if (testnext(ls, '=')) - nexps = explist1(ls, &e); - else { - e.k = VVOID; - nexps = 0; - } - adjust_assign(ls, nvars, nexps, &e); - adjustlocalvars(ls, nvars); -} - - -static int funcname (LexState *ls, expdesc *v) { - /* funcname -> NAME {field} [`:' NAME] */ - int needself = 0; - singlevar(ls, v); - while (ls->t.token == '.') - field(ls, v); - if (ls->t.token == ':') { - needself = 1; - field(ls, v); - } - return needself; -} - - -static void funcstat (LexState *ls, int line) { - /* funcstat -> FUNCTION funcname body */ - int needself; - expdesc v, b; - luaX_next(ls); /* skip FUNCTION */ - needself = funcname(ls, &v); - body(ls, &b, needself, line); - luaK_storevar(ls->fs, &v, &b); - luaK_fixline(ls->fs, line); /* definition `happens' in the first line */ -} - - -static void exprstat (LexState *ls) { - /* stat -> func | assignment */ - FuncState *fs = ls->fs; - struct LHS_assign v; - primaryexp(ls, &v.v); - if (v.v.k == VCALL) /* stat -> func */ - SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */ - else { /* stat -> assignment */ - v.prev = NULL; - assignment(ls, &v, 1); - } -} - - -static void retstat (LexState *ls) { - /* stat -> RETURN explist */ - FuncState *fs = ls->fs; - expdesc e; - int first, nret; /* registers with returned values */ - luaX_next(ls); /* skip RETURN */ - if (block_follow(ls->t.token) || ls->t.token == ';') - first = nret = 0; /* return no values */ - else { - nret = explist1(ls, &e); /* optional return values */ - if (hasmultret(e.k)) { - luaK_setmultret(fs, &e); - if (e.k == VCALL && nret == 1) { /* tail call? */ - SET_OPCODE(getcode(fs,&e), OP_TAILCALL); - lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); - } - first = fs->nactvar; - nret = LUA_MULTRET; /* return all values */ - } - else { - if (nret == 1) /* only one single value? */ - first = luaK_exp2anyreg(fs, &e); - else { - luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ - first = fs->nactvar; /* return all `active' values */ - lua_assert(nret == fs->freereg - first); - } - } - } - luaK_ret(fs, first, nret); -} - - -static int statement (LexState *ls) { - int line = ls->linenumber; /* may be needed for error messages */ - switch (ls->t.token) { - case TK_IF: { /* stat -> ifstat */ - ifstat(ls, line); - return 0; - } - case TK_WHILE: { /* stat -> whilestat */ - whilestat(ls, line); - return 0; - } - case TK_DO: { /* stat -> DO block END */ - luaX_next(ls); /* skip DO */ - block(ls); - check_match(ls, TK_END, TK_DO, line); - return 0; - } - case TK_FOR: { /* stat -> forstat */ - forstat(ls, line); - return 0; - } - case TK_REPEAT: { /* stat -> repeatstat */ - repeatstat(ls, line); - return 0; - } - case TK_FUNCTION: { - funcstat(ls, line); /* stat -> funcstat */ - return 0; - } - case TK_LOCAL: { /* stat -> localstat */ - luaX_next(ls); /* skip LOCAL */ - if (testnext(ls, TK_FUNCTION)) /* local function? */ - localfunc(ls); - else - localstat(ls); - return 0; - } - case TK_RETURN: { /* stat -> retstat */ - retstat(ls); - return 1; /* must be last statement */ - } - case TK_BREAK: { /* stat -> breakstat */ - luaX_next(ls); /* skip BREAK */ - breakstat(ls); - return 1; /* must be last statement */ - } - default: { - exprstat(ls); - return 0; /* to avoid warnings */ - } - } -} - - -static void chunk (LexState *ls) { - /* chunk -> { stat [`;'] } */ - int islast = 0; - enterlevel(ls); - while (!islast && !block_follow(ls->t.token)) { - islast = statement(ls); - testnext(ls, ';'); - lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && - ls->fs->freereg >= ls->fs->nactvar); - ls->fs->freereg = ls->fs->nactvar; /* free registers */ - } - leavelevel(ls); -} - -/* }====================================================================== */ |