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author | darylm503 <darylm503@Edk2> | 2014-11-07 20:18:01 +0000 |
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committer | darylm503 <darylm503@Edk2> | 2014-11-07 20:18:01 +0000 |
commit | 16a5fed65808adf648004b34f98718301d718fa2 (patch) | |
tree | 1fd24a832f20c1ce4e1e52e0020513d0d1ef5ae8 /AppPkg/Applications/Lua/src/lparser.c | |
parent | c058d59f40b4a95c218cd171ff976bee1ff487e2 (diff) | |
download | edk2-16a5fed65808adf648004b34f98718301d718fa2.tar.gz edk2-16a5fed65808adf648004b34f98718301d718fa2.tar.bz2 edk2-16a5fed65808adf648004b34f98718301d718fa2.zip |
AppPkg: Add the Lua interpreter and library.
StdLib: Add support and include files for Lua.
The sources for the Lua standalone interpreter, as well as its library, have been added to AppPkg/Applications/Lua. The Lua library, LuaLib, can be used to embed Lua into new applications.
The Lua header files, needed for both building and embedding, are located in StdLib/Include/Lua. The original versions of these header files, in the source directory, have been converted into stubs that reference the include files in StdLib. This allows us to keep the Lua sources as close to the distributed version as possible.
Documentation is contained in the Lua/doc directory. Further information is available at www.lua.org.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed Off by: Bruce Maynard <Bruce.Maynard@Emulex.Com>
Reviewed by: Daryl McDaniel <daryl.mcdaniel@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16313 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'AppPkg/Applications/Lua/src/lparser.c')
-rw-r--r-- | AppPkg/Applications/Lua/src/lparser.c | 1638 |
1 files changed, 1638 insertions, 0 deletions
diff --git a/AppPkg/Applications/Lua/src/lparser.c b/AppPkg/Applications/Lua/src/lparser.c new file mode 100644 index 0000000000..fa693824a1 --- /dev/null +++ b/AppPkg/Applications/Lua/src/lparser.c @@ -0,0 +1,1638 @@ +/* +** $Id: lparser.c,v 2.130.1.1 2013/04/12 18:48:47 roberto Exp $ +** Lua Parser +** See Copyright Notice in lua.h +*/ + + +#include <string.h> + +#define lparser_c +#define LUA_CORE + +#include "lua.h" + +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "llex.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" + + + +/* maximum number of local variables per function (must be smaller + than 250, due to the bytecode format) */ +#define MAXVARS 200 + + +#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) + + + +/* +** nodes for block list (list of active blocks) +*/ +typedef struct BlockCnt { + struct BlockCnt *previous; /* chain */ + short firstlabel; /* index of first label in this block */ + short firstgoto; /* index of first pending goto in this block */ + lu_byte nactvar; /* # active locals outside the block */ + lu_byte upval; /* true if some variable in the block is an upvalue */ + lu_byte isloop; /* true if `block' is a loop */ +} BlockCnt; + + + +/* +** prototypes for recursive non-terminal functions +*/ +static void statement (LexState *ls); +static void expr (LexState *ls, expdesc *v); + + +static void anchor_token (LexState *ls) { + /* last token from outer function must be EOS */ + lua_assert(ls->fs != NULL || ls->t.token == TK_EOS); + if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) { + TString *ts = ls->t.seminfo.ts; + luaX_newstring(ls, getstr(ts), ts->tsv.len); + } +} + + +/* semantic error */ +static l_noret semerror (LexState *ls, const char *msg) { + ls->t.token = 0; /* remove 'near to' from final message */ + luaX_syntaxerror(ls, msg); +} + + +static l_noret error_expected (LexState *ls, int token) { + luaX_syntaxerror(ls, + luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token))); +} + + +static l_noret errorlimit (FuncState *fs, int limit, const char *what) { + lua_State *L = fs->ls->L; + const char *msg; + int line = fs->f->linedefined; + const char *where = (line == 0) + ? "main function" + : luaO_pushfstring(L, "function at line %d", line); + msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s", + what, limit, where); + luaX_syntaxerror(fs->ls, msg); +} + + +static void checklimit (FuncState *fs, int v, int l, const char *what) { + if (v > l) errorlimit(fs, l, what); +} + + +static int testnext (LexState *ls, int c) { + if (ls->t.token == c) { + luaX_next(ls); + return 1; + } + else return 0; +} + + +static void check (LexState *ls, int c) { + if (ls->t.token != c) + error_expected(ls, c); +} + + +static void checknext (LexState *ls, int c) { + check(ls, c); + luaX_next(ls); +} + + +#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } + + + +static void check_match (LexState *ls, int what, int who, int where) { + if (!testnext(ls, what)) { + if (where == ls->linenumber) + error_expected(ls, what); + else { + luaX_syntaxerror(ls, luaO_pushfstring(ls->L, + "%s expected (to close %s at line %d)", + luaX_token2str(ls, what), luaX_token2str(ls, who), where)); + } + } +} + + +static TString *str_checkname (LexState *ls) { + TString *ts; + check(ls, TK_NAME); + ts = ls->t.seminfo.ts; + luaX_next(ls); + return ts; +} + + +static void init_exp (expdesc *e, expkind k, int i) { + e->f = e->t = NO_JUMP; + e->k = k; + e->u.info = i; +} + + +static void codestring (LexState *ls, expdesc *e, TString *s) { + init_exp(e, VK, luaK_stringK(ls->fs, s)); +} + + +static void checkname (LexState *ls, expdesc *e) { + codestring(ls, e, str_checkname(ls)); +} + + +static int registerlocalvar (LexState *ls, TString *varname) { + FuncState *fs = ls->fs; + Proto *f = fs->f; + int oldsize = f->sizelocvars; + luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, + LocVar, SHRT_MAX, "local variables"); + while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL; + f->locvars[fs->nlocvars].varname = varname; + luaC_objbarrier(ls->L, f, varname); + return fs->nlocvars++; +} + + +static void new_localvar (LexState *ls, TString *name) { + FuncState *fs = ls->fs; + Dyndata *dyd = ls->dyd; + int reg = registerlocalvar(ls, name); + checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, + MAXVARS, "local variables"); + luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1, + dyd->actvar.size, Vardesc, MAX_INT, "local variables"); + dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg); +} + + +static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) { + new_localvar(ls, luaX_newstring(ls, name, sz)); +} + +#define new_localvarliteral(ls,v) \ + new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1) + + +static LocVar *getlocvar (FuncState *fs, int i) { + int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx; + lua_assert(idx < fs->nlocvars); + return &fs->f->locvars[idx]; +} + + +static void adjustlocalvars (LexState *ls, int nvars) { + FuncState *fs = ls->fs; + fs->nactvar = cast_byte(fs->nactvar + nvars); + for (; nvars; nvars--) { + getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc; + } +} + + +static void removevars (FuncState *fs, int tolevel) { + fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel); + while (fs->nactvar > tolevel) + getlocvar(fs, --fs->nactvar)->endpc = fs->pc; +} + + +static int searchupvalue (FuncState *fs, TString *name) { + int i; + Upvaldesc *up = fs->f->upvalues; + for (i = 0; i < fs->nups; i++) { + if (luaS_eqstr(up[i].name, name)) return i; + } + return -1; /* not found */ +} + + +static int newupvalue (FuncState *fs, TString *name, expdesc *v) { + Proto *f = fs->f; + int oldsize = f->sizeupvalues; + checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues"); + luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues, + Upvaldesc, MAXUPVAL, "upvalues"); + while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL; + f->upvalues[fs->nups].instack = (v->k == VLOCAL); + f->upvalues[fs->nups].idx = cast_byte(v->u.info); + f->upvalues[fs->nups].name = name; + luaC_objbarrier(fs->ls->L, f, name); + return fs->nups++; +} + + +static int searchvar (FuncState *fs, TString *n) { + int i; + for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) { + if (luaS_eqstr(n, getlocvar(fs, i)->varname)) + return i; + } + return -1; /* not found */ +} + + +/* + Mark block where variable at given level was defined + (to emit close instructions later). +*/ +static void markupval (FuncState *fs, int level) { + BlockCnt *bl = fs->bl; + while (bl->nactvar > level) bl = bl->previous; + bl->upval = 1; +} + + +/* + Find variable with given name 'n'. If it is an upvalue, add this + upvalue into all intermediate functions. +*/ +static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { + if (fs == NULL) /* no more levels? */ + return VVOID; /* default is global */ + else { + int v = searchvar(fs, n); /* look up locals at current level */ + if (v >= 0) { /* found? */ + init_exp(var, VLOCAL, v); /* variable is local */ + if (!base) + markupval(fs, v); /* local will be used as an upval */ + return VLOCAL; + } + else { /* not found as local at current level; try upvalues */ + int idx = searchupvalue(fs, n); /* try existing upvalues */ + if (idx < 0) { /* not found? */ + if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */ + return VVOID; /* not found; is a global */ + /* else was LOCAL or UPVAL */ + idx = newupvalue(fs, n, var); /* will be a new upvalue */ + } + init_exp(var, VUPVAL, idx); + return VUPVAL; + } + } +} + + +static void singlevar (LexState *ls, expdesc *var) { + TString *varname = str_checkname(ls); + FuncState *fs = ls->fs; + if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */ + expdesc key; + singlevaraux(fs, ls->envn, var, 1); /* get environment variable */ + lua_assert(var->k == VLOCAL || var->k == VUPVAL); + codestring(ls, &key, varname); /* key is variable name */ + luaK_indexed(fs, var, &key); /* env[varname] */ + } +} + + +static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { + FuncState *fs = ls->fs; + int extra = nvars - nexps; + if (hasmultret(e->k)) { + extra++; /* includes call itself */ + if (extra < 0) extra = 0; + luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ + if (extra > 1) luaK_reserveregs(fs, extra-1); + } + else { + if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ + if (extra > 0) { + int reg = fs->freereg; + luaK_reserveregs(fs, extra); + luaK_nil(fs, reg, extra); + } + } +} + + +static void enterlevel (LexState *ls) { + lua_State *L = ls->L; + ++L->nCcalls; + checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels"); +} + + +#define leavelevel(ls) ((ls)->L->nCcalls--) + + +static void closegoto (LexState *ls, int g, Labeldesc *label) { + int i; + FuncState *fs = ls->fs; + Labellist *gl = &ls->dyd->gt; + Labeldesc *gt = &gl->arr[g]; + lua_assert(luaS_eqstr(gt->name, label->name)); + if (gt->nactvar < label->nactvar) { + TString *vname = getlocvar(fs, gt->nactvar)->varname; + const char *msg = luaO_pushfstring(ls->L, + "<goto %s> at line %d jumps into the scope of local " LUA_QS, + getstr(gt->name), gt->line, getstr(vname)); + semerror(ls, msg); + } + luaK_patchlist(fs, gt->pc, label->pc); + /* remove goto from pending list */ + for (i = g; i < gl->n - 1; i++) + gl->arr[i] = gl->arr[i + 1]; + gl->n--; +} + + +/* +** try to close a goto with existing labels; this solves backward jumps +*/ +static int findlabel (LexState *ls, int g) { + int i; + BlockCnt *bl = ls->fs->bl; + Dyndata *dyd = ls->dyd; + Labeldesc *gt = &dyd->gt.arr[g]; + /* check labels in current block for a match */ + for (i = bl->firstlabel; i < dyd->label.n; i++) { + Labeldesc *lb = &dyd->label.arr[i]; + if (luaS_eqstr(lb->name, gt->name)) { /* correct label? */ + if (gt->nactvar > lb->nactvar && + (bl->upval || dyd->label.n > bl->firstlabel)) + luaK_patchclose(ls->fs, gt->pc, lb->nactvar); + closegoto(ls, g, lb); /* close it */ + return 1; + } + } + return 0; /* label not found; cannot close goto */ +} + + +static int newlabelentry (LexState *ls, Labellist *l, TString *name, + int line, int pc) { + int n = l->n; + luaM_growvector(ls->L, l->arr, n, l->size, + Labeldesc, SHRT_MAX, "labels/gotos"); + l->arr[n].name = name; + l->arr[n].line = line; + l->arr[n].nactvar = ls->fs->nactvar; + l->arr[n].pc = pc; + l->n++; + return n; +} + + +/* +** check whether new label 'lb' matches any pending gotos in current +** block; solves forward jumps +*/ +static void findgotos (LexState *ls, Labeldesc *lb) { + Labellist *gl = &ls->dyd->gt; + int i = ls->fs->bl->firstgoto; + while (i < gl->n) { + if (luaS_eqstr(gl->arr[i].name, lb->name)) + closegoto(ls, i, lb); + else + i++; + } +} + + +/* +** "export" pending gotos to outer level, to check them against +** outer labels; if the block being exited has upvalues, and +** the goto exits the scope of any variable (which can be the +** upvalue), close those variables being exited. +*/ +static void movegotosout (FuncState *fs, BlockCnt *bl) { + int i = bl->firstgoto; + Labellist *gl = &fs->ls->dyd->gt; + /* correct pending gotos to current block and try to close it + with visible labels */ + while (i < gl->n) { + Labeldesc *gt = &gl->arr[i]; + if (gt->nactvar > bl->nactvar) { + if (bl->upval) + luaK_patchclose(fs, gt->pc, bl->nactvar); + gt->nactvar = bl->nactvar; + } + if (!findlabel(fs->ls, i)) + i++; /* move to next one */ + } +} + + +static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) { + bl->isloop = isloop; + bl->nactvar = fs->nactvar; + bl->firstlabel = (short)fs->ls->dyd->label.n; + bl->firstgoto = (short)fs->ls->dyd->gt.n; + bl->upval = 0; + bl->previous = fs->bl; + fs->bl = bl; + lua_assert(fs->freereg == fs->nactvar); +} + + +/* +** create a label named "break" to resolve break statements +*/ +static void breaklabel (LexState *ls) { + TString *n = luaS_new(ls->L, "break"); + int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc); + findgotos(ls, &ls->dyd->label.arr[l]); +} + +/* +** generates an error for an undefined 'goto'; choose appropriate +** message when label name is a reserved word (which can only be 'break') +*/ +static l_noret undefgoto (LexState *ls, Labeldesc *gt) { + const char *msg = isreserved(gt->name) + ? "<%s> at line %d not inside a loop" + : "no visible label " LUA_QS " for <goto> at line %d"; + msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line); + semerror(ls, msg); +} + + +static void leaveblock (FuncState *fs) { + BlockCnt *bl = fs->bl; + LexState *ls = fs->ls; + if (bl->previous && bl->upval) { + /* create a 'jump to here' to close upvalues */ + int j = luaK_jump(fs); + luaK_patchclose(fs, j, bl->nactvar); + luaK_patchtohere(fs, j); + } + if (bl->isloop) + breaklabel(ls); /* close pending breaks */ + fs->bl = bl->previous; + removevars(fs, bl->nactvar); + lua_assert(bl->nactvar == fs->nactvar); + fs->freereg = fs->nactvar; /* free registers */ + ls->dyd->label.n = bl->firstlabel; /* remove local labels */ + if (bl->previous) /* inner block? */ + movegotosout(fs, bl); /* update pending gotos to outer block */ + else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */ + undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */ +} + + +/* +** adds a new prototype into list of prototypes +*/ +static Proto *addprototype (LexState *ls) { + Proto *clp; + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; /* prototype of current function */ + if (fs->np >= f->sizep) { + int oldsize = f->sizep; + luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions"); + while (oldsize < f->sizep) f->p[oldsize++] = NULL; + } + f->p[fs->np++] = clp = luaF_newproto(L); + luaC_objbarrier(L, f, clp); + return clp; +} + + +/* +** codes instruction to create new closure in parent function. +** The OP_CLOSURE instruction must use the last available register, +** so that, if it invokes the GC, the GC knows which registers +** are in use at that time. +*/ +static void codeclosure (LexState *ls, expdesc *v) { + FuncState *fs = ls->fs->prev; + init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1)); + luaK_exp2nextreg(fs, v); /* fix it at the last register */ +} + + +static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { + lua_State *L = ls->L; + Proto *f; + fs->prev = ls->fs; /* linked list of funcstates */ + fs->ls = ls; + ls->fs = fs; + fs->pc = 0; + fs->lasttarget = 0; + fs->jpc = NO_JUMP; + fs->freereg = 0; + fs->nk = 0; + fs->np = 0; + fs->nups = 0; + fs->nlocvars = 0; + fs->nactvar = 0; + fs->firstlocal = ls->dyd->actvar.n; + fs->bl = NULL; + f = fs->f; + f->source = ls->source; + f->maxstacksize = 2; /* registers 0/1 are always valid */ + fs->h = luaH_new(L); + /* anchor table of constants (to avoid being collected) */ + sethvalue2s(L, L->top, fs->h); + incr_top(L); + enterblock(fs, bl, 0); +} + + +static void close_func (LexState *ls) { + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; + luaK_ret(fs, 0, 0); /* final return */ + leaveblock(fs); + luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); + f->sizecode = fs->pc; + luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); + f->sizelineinfo = fs->pc; + luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue); + f->sizek = fs->nk; + luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); + f->sizep = fs->np; + luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); + f->sizelocvars = fs->nlocvars; + luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); + f->sizeupvalues = fs->nups; + lua_assert(fs->bl == NULL); + ls->fs = fs->prev; + /* last token read was anchored in defunct function; must re-anchor it */ + anchor_token(ls); + L->top--; /* pop table of constants */ + luaC_checkGC(L); +} + + + +/*============================================================*/ +/* GRAMMAR RULES */ +/*============================================================*/ + + +/* +** check whether current token is in the follow set of a block. +** 'until' closes syntactical blocks, but do not close scope, +** so it handled in separate. +*/ +static int block_follow (LexState *ls, int withuntil) { + switch (ls->t.token) { + case TK_ELSE: case TK_ELSEIF: + case TK_END: case TK_EOS: + return 1; + case TK_UNTIL: return withuntil; + default: return 0; + } +} + + +static void statlist (LexState *ls) { + /* statlist -> { stat [`;'] } */ + while (!block_follow(ls, 1)) { + if (ls->t.token == TK_RETURN) { + statement(ls); + return; /* 'return' must be last statement */ + } + statement(ls); + } +} + + +static void fieldsel (LexState *ls, expdesc *v) { + /* fieldsel -> ['.' | ':'] NAME */ + FuncState *fs = ls->fs; + expdesc key; + luaK_exp2anyregup(fs, v); + luaX_next(ls); /* skip the dot or colon */ + checkname(ls, &key); + luaK_indexed(fs, v, &key); +} + + +static void yindex (LexState *ls, expdesc *v) { + /* index -> '[' expr ']' */ + luaX_next(ls); /* skip the '[' */ + expr(ls, v); + luaK_exp2val(ls->fs, v); + checknext(ls, ']'); +} + + +/* +** {====================================================================== +** Rules for Constructors +** ======================================================================= +*/ + + +struct ConsControl { + expdesc v; /* last list item read */ + expdesc *t; /* table descriptor */ + int nh; /* total number of `record' elements */ + int na; /* total number of array elements */ + int tostore; /* number of array elements pending to be stored */ +}; + + +static void recfield (LexState *ls, struct ConsControl *cc) { + /* recfield -> (NAME | `['exp1`]') = exp1 */ + FuncState *fs = ls->fs; + int reg = ls->fs->freereg; + expdesc key, val; + int rkkey; + if (ls->t.token == TK_NAME) { + checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); + checkname(ls, &key); + } + else /* ls->t.token == '[' */ + yindex(ls, &key); + cc->nh++; + checknext(ls, '='); + rkkey = luaK_exp2RK(fs, &key); + expr(ls, &val); + luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val)); + fs->freereg = (lu_byte)reg; /* free registers */ +} + + +static void closelistfield (FuncState *fs, struct ConsControl *cc) { + if (cc->v.k == VVOID) return; /* there is no list item */ + luaK_exp2nextreg(fs, &cc->v); + cc->v.k = VVOID; + if (cc->tostore == LFIELDS_PER_FLUSH) { + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ + cc->tostore = 0; /* no more items pending */ + } +} + + +static void lastlistfield (FuncState *fs, struct ConsControl *cc) { + if (cc->tostore == 0) return; + if (hasmultret(cc->v.k)) { + luaK_setmultret(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET); + cc->na--; /* do not count last expression (unknown number of elements) */ + } + else { + if (cc->v.k != VVOID) + luaK_exp2nextreg(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); + } +} + + +static void listfield (LexState *ls, struct ConsControl *cc) { + /* listfield -> exp */ + expr(ls, &cc->v); + checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); + cc->na++; + cc->tostore++; +} + + +static void field (LexState *ls, struct ConsControl *cc) { + /* field -> listfield | recfield */ + switch(ls->t.token) { + case TK_NAME: { /* may be 'listfield' or 'recfield' */ + if (luaX_lookahead(ls) != '=') /* expression? */ + listfield(ls, cc); + else + recfield(ls, cc); + break; + } + case '[': { + recfield(ls, cc); + break; + } + default: { + listfield(ls, cc); + break; + } + } +} + + +static void constructor (LexState *ls, expdesc *t) { + /* constructor -> '{' [ field { sep field } [sep] ] '}' + sep -> ',' | ';' */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); + struct ConsControl cc; + cc.na = cc.nh = cc.tostore = 0; + cc.t = t; + init_exp(t, VRELOCABLE, pc); + init_exp(&cc.v, VVOID, 0); /* no value (yet) */ + luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */ + checknext(ls, '{'); + do { + lua_assert(cc.v.k == VVOID || cc.tostore > 0); + if (ls->t.token == '}') break; + closelistfield(fs, &cc); + field(ls, &cc); + } while (testnext(ls, ',') || testnext(ls, ';')); + check_match(ls, '}', '{', line); + lastlistfield(fs, &cc); + SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ + SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */ +} + +/* }====================================================================== */ + + + +static void parlist (LexState *ls) { + /* parlist -> [ param { `,' param } ] */ + FuncState *fs = ls->fs; + Proto *f = fs->f; + int nparams = 0; + f->is_vararg = 0; + if (ls->t.token != ')') { /* is `parlist' not empty? */ + do { + switch (ls->t.token) { + case TK_NAME: { /* param -> NAME */ + new_localvar(ls, str_checkname(ls)); + nparams++; + break; + } + case TK_DOTS: { /* param -> `...' */ + luaX_next(ls); + f->is_vararg = 1; + break; + } + default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected"); + } + } while (!f->is_vararg && testnext(ls, ',')); + } + adjustlocalvars(ls, nparams); + f->numparams = cast_byte(fs->nactvar); + luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ +} + + +static void body (LexState *ls, expdesc *e, int ismethod, int line) { + /* body -> `(' parlist `)' block END */ + FuncState new_fs; + BlockCnt bl; + new_fs.f = addprototype(ls); + new_fs.f->linedefined = line; + open_func(ls, &new_fs, &bl); + checknext(ls, '('); + if (ismethod) { + new_localvarliteral(ls, "self"); /* create 'self' parameter */ + adjustlocalvars(ls, 1); + } + parlist(ls); + checknext(ls, ')'); + statlist(ls); + new_fs.f->lastlinedefined = ls->linenumber; + check_match(ls, TK_END, TK_FUNCTION, line); + codeclosure(ls, e); + close_func(ls); +} + + +static int explist (LexState *ls, expdesc *v) { + /* explist -> expr { `,' expr } */ + int n = 1; /* at least one expression */ + expr(ls, v); + while (testnext(ls, ',')) { + luaK_exp2nextreg(ls->fs, v); + expr(ls, v); + n++; + } + return n; +} + + +static void funcargs (LexState *ls, expdesc *f, int line) { + FuncState *fs = ls->fs; + expdesc args; + int base, nparams; + switch (ls->t.token) { + case '(': { /* funcargs -> `(' [ explist ] `)' */ + luaX_next(ls); + if (ls->t.token == ')') /* arg list is empty? */ + args.k = VVOID; + else { + explist(ls, &args); + luaK_setmultret(fs, &args); + } + check_match(ls, ')', '(', line); + break; + } + case '{': { /* funcargs -> constructor */ + constructor(ls, &args); + break; + } + case TK_STRING: { /* funcargs -> STRING */ + codestring(ls, &args, ls->t.seminfo.ts); + luaX_next(ls); /* must use `seminfo' before `next' */ + break; + } + default: { + luaX_syntaxerror(ls, "function arguments expected"); + } + } + lua_assert(f->k == VNONRELOC); + base = f->u.info; /* base register for call */ + if (hasmultret(args.k)) + nparams = LUA_MULTRET; /* open call */ + else { + if (args.k != VVOID) + luaK_exp2nextreg(fs, &args); /* close last argument */ + nparams = fs->freereg - (base+1); + } + init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); + luaK_fixline(fs, line); + fs->freereg = (lu_byte)base + 1; /* call remove function and arguments and leaves + (unless changed) one result */ +} + + + + +/* +** {====================================================================== +** Expression parsing +** ======================================================================= +*/ + + +static void primaryexp (LexState *ls, expdesc *v) { + /* primaryexp -> NAME | '(' expr ')' */ + switch (ls->t.token) { + case '(': { + int line = ls->linenumber; + luaX_next(ls); + expr(ls, v); + check_match(ls, ')', '(', line); + luaK_dischargevars(ls->fs, v); + return; + } + case TK_NAME: { + singlevar(ls, v); + return; + } + default: { + luaX_syntaxerror(ls, "unexpected symbol"); + } + } +} + + +static void suffixedexp (LexState *ls, expdesc *v) { + /* suffixedexp -> + primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + primaryexp(ls, v); + for (;;) { + switch (ls->t.token) { + case '.': { /* fieldsel */ + fieldsel(ls, v); + break; + } + case '[': { /* `[' exp1 `]' */ + expdesc key; + luaK_exp2anyregup(fs, v); + yindex(ls, &key); + luaK_indexed(fs, v, &key); + break; + } + case ':': { /* `:' NAME funcargs */ + expdesc key; + luaX_next(ls); + checkname(ls, &key); + luaK_self(fs, v, &key); + funcargs(ls, v, line); + break; + } + case '(': case TK_STRING: case '{': { /* funcargs */ + luaK_exp2nextreg(fs, v); + funcargs(ls, v, line); + break; + } + default: return; + } + } +} + + +static void simpleexp (LexState *ls, expdesc *v) { + /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... | + constructor | FUNCTION body | suffixedexp */ + switch (ls->t.token) { + case TK_NUMBER: { + init_exp(v, VKNUM, 0); + v->u.nval = ls->t.seminfo.r; + break; + } + case TK_STRING: { + codestring(ls, v, ls->t.seminfo.ts); + break; + } + case TK_NIL: { + init_exp(v, VNIL, 0); + break; + } + case TK_TRUE: { + init_exp(v, VTRUE, 0); + break; + } + case TK_FALSE: { + init_exp(v, VFALSE, 0); + break; + } + case TK_DOTS: { /* vararg */ + FuncState *fs = ls->fs; + check_condition(ls, fs->f->is_vararg, + "cannot use " LUA_QL("...") " outside a vararg function"); + init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0)); + break; + } + case '{': { /* constructor */ + constructor(ls, v); + return; + } + case TK_FUNCTION: { + luaX_next(ls); + body(ls, v, 0, ls->linenumber); + return; + } + default: { + suffixedexp(ls, v); + return; + } + } + luaX_next(ls); +} + + +static UnOpr getunopr (int op) { + switch (op) { + case TK_NOT: return OPR_NOT; + case '-': return OPR_MINUS; + case '#': return OPR_LEN; + default: return OPR_NOUNOPR; + } +} + + +static BinOpr getbinopr (int op) { + switch (op) { + case '+': return OPR_ADD; + case '-': return OPR_SUB; + case '*': return OPR_MUL; + case '/': return OPR_DIV; + case '%': return OPR_MOD; + case '^': return OPR_POW; + case TK_CONCAT: return OPR_CONCAT; + case TK_NE: return OPR_NE; + case TK_EQ: return OPR_EQ; + case '<': return OPR_LT; + case TK_LE: return OPR_LE; + case '>': return OPR_GT; + case TK_GE: return OPR_GE; + case TK_AND: return OPR_AND; + case TK_OR: return OPR_OR; + default: return OPR_NOBINOPR; + } +} + + +static const struct { + lu_byte left; /* left priority for each binary operator */ + lu_byte right; /* right priority */ +} priority[] = { /* ORDER OPR */ + {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `*' `/' `%' */ + {10, 9}, {5, 4}, /* ^, .. (right associative) */ + {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */ + {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */ + {2, 2}, {1, 1} /* and, or */ +}; + +#define UNARY_PRIORITY 8 /* priority for unary operators */ + + +/* +** subexpr -> (simpleexp | unop subexpr) { binop subexpr } +** where `binop' is any binary operator with a priority higher than `limit' +*/ +static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { + BinOpr op; + UnOpr uop; + enterlevel(ls); + uop = getunopr(ls->t.token); + if (uop != OPR_NOUNOPR) { + int line = ls->linenumber; + luaX_next(ls); + subexpr(ls, v, UNARY_PRIORITY); + luaK_prefix(ls->fs, uop, v, line); + } + else simpleexp(ls, v); + /* expand while operators have priorities higher than `limit' */ + op = getbinopr(ls->t.token); + while (op != OPR_NOBINOPR && priority[op].left > limit) { + expdesc v2; + BinOpr nextop; + int line = ls->linenumber; + luaX_next(ls); + luaK_infix(ls->fs, op, v); + /* read sub-expression with higher priority */ + nextop = subexpr(ls, &v2, priority[op].right); + luaK_posfix(ls->fs, op, v, &v2, line); + op = nextop; + } + leavelevel(ls); + return op; /* return first untreated operator */ +} + + +static void expr (LexState *ls, expdesc *v) { + subexpr(ls, v, 0); +} + +/* }==================================================================== */ + + + +/* +** {====================================================================== +** Rules for Statements +** ======================================================================= +*/ + + +static void block (LexState *ls) { + /* block -> statlist */ + FuncState *fs = ls->fs; + BlockCnt bl; + enterblock(fs, &bl, 0); + statlist(ls); + leaveblock(fs); +} + + +/* +** structure to chain all variables in the left-hand side of an +** assignment +*/ +struct LHS_assign { + struct LHS_assign *prev; + expdesc v; /* variable (global, local, upvalue, or indexed) */ +}; + + +/* +** check whether, in an assignment to an upvalue/local variable, the +** upvalue/local variable is begin used in a previous assignment to a +** table. If so, save original upvalue/local value in a safe place and +** use this safe copy in the previous assignment. +*/ +static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { + FuncState *fs = ls->fs; + int extra = fs->freereg; /* eventual position to save local variable */ + int conflict = 0; + for (; lh; lh = lh->prev) { /* check all previous assignments */ + if (lh->v.k == VINDEXED) { /* assigning to a table? */ + /* table is the upvalue/local being assigned now? */ + if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) { + conflict = 1; + lh->v.u.ind.vt = VLOCAL; + lh->v.u.ind.t = (lu_byte)extra; /* previous assignment will use safe copy */ + } + /* index is the local being assigned? (index cannot be upvalue) */ + if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) { + conflict = 1; + lh->v.u.ind.idx = (short)extra; /* previous assignment will use safe copy */ + } + } + } + if (conflict) { + /* copy upvalue/local value to a temporary (in position 'extra') */ + OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; + luaK_codeABC(fs, op, extra, v->u.info, 0); + luaK_reserveregs(fs, 1); + } +} + + +static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { + expdesc e; + check_condition(ls, vkisvar(lh->v.k), "syntax error"); + if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */ + struct LHS_assign nv; + nv.prev = lh; + suffixedexp(ls, &nv.v); + if (nv.v.k != VINDEXED) + check_conflict(ls, lh, &nv.v); + checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS, + "C levels"); + assignment(ls, &nv, nvars+1); + } + else { /* assignment -> `=' explist */ + int nexps; + checknext(ls, '='); + nexps = explist(ls, &e); + if (nexps != nvars) { + adjust_assign(ls, nvars, nexps, &e); + if (nexps > nvars) + ls->fs->freereg -= (lu_byte)(nexps - nvars); /* remove extra values */ + } + else { + luaK_setoneret(ls->fs, &e); /* close last expression */ + luaK_storevar(ls->fs, &lh->v, &e); + return; /* avoid default */ + } + } + init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ + luaK_storevar(ls->fs, &lh->v, &e); +} + + +static int cond (LexState *ls) { + /* cond -> exp */ + expdesc v; + expr(ls, &v); /* read condition */ + if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */ + luaK_goiftrue(ls->fs, &v); + return v.f; +} + + +static void gotostat (LexState *ls, int pc) { + int line = ls->linenumber; + TString *label; + int g; + if (testnext(ls, TK_GOTO)) + label = str_checkname(ls); + else { + luaX_next(ls); /* skip break */ + label = luaS_new(ls->L, "break"); + } + g = newlabelentry(ls, &ls->dyd->gt, label, line, pc); + findlabel(ls, g); /* close it if label already defined */ +} + + +/* check for repeated labels on the same block */ +static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) { + int i; + for (i = fs->bl->firstlabel; i < ll->n; i++) { + if (luaS_eqstr(label, ll->arr[i].name)) { + const char *msg = luaO_pushfstring(fs->ls->L, + "label " LUA_QS " already defined on line %d", + getstr(label), ll->arr[i].line); + semerror(fs->ls, msg); + } + } +} + + +/* skip no-op statements */ +static void skipnoopstat (LexState *ls) { + while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) + statement(ls); +} + + +static void labelstat (LexState *ls, TString *label, int line) { + /* label -> '::' NAME '::' */ + FuncState *fs = ls->fs; + Labellist *ll = &ls->dyd->label; + int l; /* index of new label being created */ + checkrepeated(fs, ll, label); /* check for repeated labels */ + checknext(ls, TK_DBCOLON); /* skip double colon */ + /* create new entry for this label */ + l = newlabelentry(ls, ll, label, line, fs->pc); + skipnoopstat(ls); /* skip other no-op statements */ + if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */ + /* assume that locals are already out of scope */ + ll->arr[l].nactvar = fs->bl->nactvar; + } + findgotos(ls, &ll->arr[l]); +} + + +static void whilestat (LexState *ls, int line) { + /* whilestat -> WHILE cond DO block END */ + FuncState *fs = ls->fs; + int whileinit; + int condexit; + BlockCnt bl; + luaX_next(ls); /* skip WHILE */ + whileinit = luaK_getlabel(fs); + condexit = cond(ls); + enterblock(fs, &bl, 1); + checknext(ls, TK_DO); + block(ls); + luaK_jumpto(fs, whileinit); + check_match(ls, TK_END, TK_WHILE, line); + leaveblock(fs); + luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ +} + + +static void repeatstat (LexState *ls, int line) { + /* repeatstat -> REPEAT block UNTIL cond */ + int condexit; + FuncState *fs = ls->fs; + int repeat_init = luaK_getlabel(fs); + BlockCnt bl1, bl2; + enterblock(fs, &bl1, 1); /* loop block */ + enterblock(fs, &bl2, 0); /* scope block */ + luaX_next(ls); /* skip REPEAT */ + statlist(ls); + check_match(ls, TK_UNTIL, TK_REPEAT, line); + condexit = cond(ls); /* read condition (inside scope block) */ + if (bl2.upval) /* upvalues? */ + luaK_patchclose(fs, condexit, bl2.nactvar); + leaveblock(fs); /* finish scope */ + luaK_patchlist(fs, condexit, repeat_init); /* close the loop */ + leaveblock(fs); /* finish loop */ +} + + +static int exp1 (LexState *ls) { + expdesc e; + int reg; + expr(ls, &e); + luaK_exp2nextreg(ls->fs, &e); + lua_assert(e.k == VNONRELOC); + reg = e.u.info; + return reg; +} + + +static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { + /* forbody -> DO block */ + BlockCnt bl; + FuncState *fs = ls->fs; + int prep, endfor; + adjustlocalvars(ls, 3); /* control variables */ + checknext(ls, TK_DO); + prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs); + enterblock(fs, &bl, 0); /* scope for declared variables */ + adjustlocalvars(ls, nvars); + luaK_reserveregs(fs, nvars); + block(ls); + leaveblock(fs); /* end of scope for declared variables */ + luaK_patchtohere(fs, prep); + if (isnum) /* numeric for? */ + endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP); + else { /* generic for */ + luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars); + luaK_fixline(fs, line); + endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP); + } + luaK_patchlist(fs, endfor, prep + 1); + luaK_fixline(fs, line); +} + + +static void fornum (LexState *ls, TString *varname, int line) { + /* fornum -> NAME = exp1,exp1[,exp1] forbody */ + FuncState *fs = ls->fs; + int base = fs->freereg; + new_localvarliteral(ls, "(for index)"); + new_localvarliteral(ls, "(for limit)"); + new_localvarliteral(ls, "(for step)"); + new_localvar(ls, varname); + checknext(ls, '='); + exp1(ls); /* initial value */ + checknext(ls, ','); + exp1(ls); /* limit */ + if (testnext(ls, ',')) + exp1(ls); /* optional step */ + else { /* default step = 1 */ + luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1)); + luaK_reserveregs(fs, 1); + } + forbody(ls, base, line, 1, 1); +} + + +static void forlist (LexState *ls, TString *indexname) { + /* forlist -> NAME {,NAME} IN explist forbody */ + FuncState *fs = ls->fs; + expdesc e; + int nvars = 4; /* gen, state, control, plus at least one declared var */ + int line; + int base = fs->freereg; + /* create control variables */ + new_localvarliteral(ls, "(for generator)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for control)"); + /* create declared variables */ + new_localvar(ls, indexname); + while (testnext(ls, ',')) { + new_localvar(ls, str_checkname(ls)); + nvars++; + } + checknext(ls, TK_IN); + line = ls->linenumber; + adjust_assign(ls, 3, explist(ls, &e), &e); + luaK_checkstack(fs, 3); /* extra space to call generator */ + forbody(ls, base, line, nvars - 3, 0); +} + + +static void forstat (LexState *ls, int line) { + /* forstat -> FOR (fornum | forlist) END */ + FuncState *fs = ls->fs; + TString *varname; + BlockCnt bl; + enterblock(fs, &bl, 1); /* scope for loop and control variables */ + luaX_next(ls); /* skip `for' */ + varname = str_checkname(ls); /* first variable name */ + switch (ls->t.token) { + case '=': fornum(ls, varname, line); break; + case ',': case TK_IN: forlist(ls, varname); break; + default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected"); + } + check_match(ls, TK_END, TK_FOR, line); + leaveblock(fs); /* loop scope (`break' jumps to this point) */ +} + + +static void test_then_block (LexState *ls, int *escapelist) { + /* test_then_block -> [IF | ELSEIF] cond THEN block */ + BlockCnt bl; + FuncState *fs = ls->fs; + expdesc v; + int jf; /* instruction to skip 'then' code (if condition is false) */ + luaX_next(ls); /* skip IF or ELSEIF */ + expr(ls, &v); /* read condition */ + checknext(ls, TK_THEN); + if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { + luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ + enterblock(fs, &bl, 0); /* must enter block before 'goto' */ + gotostat(ls, v.t); /* handle goto/break */ + skipnoopstat(ls); /* skip other no-op statements */ + if (block_follow(ls, 0)) { /* 'goto' is the entire block? */ + leaveblock(fs); + return; /* and that is it */ + } + else /* must skip over 'then' part if condition is false */ + jf = luaK_jump(fs); + } + else { /* regular case (not goto/break) */ + luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ + enterblock(fs, &bl, 0); + jf = v.f; + } + statlist(ls); /* `then' part */ + leaveblock(fs); + if (ls->t.token == TK_ELSE || + ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ + luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ + luaK_patchtohere(fs, jf); +} + + +static void ifstat (LexState *ls, int line) { + /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ + FuncState *fs = ls->fs; + int escapelist = NO_JUMP; /* exit list for finished parts */ + test_then_block(ls, &escapelist); /* IF cond THEN block */ + while (ls->t.token == TK_ELSEIF) + test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */ + if (testnext(ls, TK_ELSE)) + block(ls); /* `else' part */ + check_match(ls, TK_END, TK_IF, line); + luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ +} + + +static void localfunc (LexState *ls) { + expdesc b; + FuncState *fs = ls->fs; + new_localvar(ls, str_checkname(ls)); /* new local variable */ + adjustlocalvars(ls, 1); /* enter its scope */ + body(ls, &b, 0, ls->linenumber); /* function created in next register */ + /* debug information will only see the variable after this point! */ + getlocvar(fs, b.u.info)->startpc = fs->pc; +} + + +static void localstat (LexState *ls) { + /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */ + int nvars = 0; + int nexps; + expdesc e; + do { + new_localvar(ls, str_checkname(ls)); + nvars++; + } while (testnext(ls, ',')); + if (testnext(ls, '=')) + nexps = explist(ls, &e); + else { + e.k = VVOID; + nexps = 0; + } + adjust_assign(ls, nvars, nexps, &e); + adjustlocalvars(ls, nvars); +} + + +static int funcname (LexState *ls, expdesc *v) { + /* funcname -> NAME {fieldsel} [`:' NAME] */ + int ismethod = 0; + singlevar(ls, v); + while (ls->t.token == '.') + fieldsel(ls, v); + if (ls->t.token == ':') { + ismethod = 1; + fieldsel(ls, v); + } + return ismethod; +} + + +static void funcstat (LexState *ls, int line) { + /* funcstat -> FUNCTION funcname body */ + int ismethod; + expdesc v, b; + luaX_next(ls); /* skip FUNCTION */ + ismethod = funcname(ls, &v); + body(ls, &b, ismethod, line); + luaK_storevar(ls->fs, &v, &b); + luaK_fixline(ls->fs, line); /* definition `happens' in the first line */ +} + + +static void exprstat (LexState *ls) { + /* stat -> func | assignment */ + FuncState *fs = ls->fs; + struct LHS_assign v; + suffixedexp(ls, &v.v); + if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */ + v.prev = NULL; + assignment(ls, &v, 1); + } + else { /* stat -> func */ + check_condition(ls, v.v.k == VCALL, "syntax error"); + SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */ + } +} + + +static void retstat (LexState *ls) { + /* stat -> RETURN [explist] [';'] */ + FuncState *fs = ls->fs; + expdesc e; + int first, nret; /* registers with returned values */ + if (block_follow(ls, 1) || ls->t.token == ';') + first = nret = 0; /* return no values */ + else { + nret = explist(ls, &e); /* optional return values */ + if (hasmultret(e.k)) { + luaK_setmultret(fs, &e); + if (e.k == VCALL && nret == 1) { /* tail call? */ + SET_OPCODE(getcode(fs,&e), OP_TAILCALL); + lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); + } + first = fs->nactvar; + nret = LUA_MULTRET; /* return all values */ + } + else { + if (nret == 1) /* only one single value? */ + first = luaK_exp2anyreg(fs, &e); + else { + luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ + first = fs->nactvar; /* return all `active' values */ + lua_assert(nret == fs->freereg - first); + } + } + } + luaK_ret(fs, first, nret); + testnext(ls, ';'); /* skip optional semicolon */ +} + + +static void statement (LexState *ls) { + int line = ls->linenumber; /* may be needed for error messages */ + enterlevel(ls); + switch (ls->t.token) { + case ';': { /* stat -> ';' (empty statement) */ + luaX_next(ls); /* skip ';' */ + break; + } + case TK_IF: { /* stat -> ifstat */ + ifstat(ls, line); + break; + } + case TK_WHILE: { /* stat -> whilestat */ + whilestat(ls, line); + break; + } + case TK_DO: { /* stat -> DO block END */ + luaX_next(ls); /* skip DO */ + block(ls); + check_match(ls, TK_END, TK_DO, line); + break; + } + case TK_FOR: { /* stat -> forstat */ + forstat(ls, line); + break; + } + case TK_REPEAT: { /* stat -> repeatstat */ + repeatstat(ls, line); + break; + } + case TK_FUNCTION: { /* stat -> funcstat */ + funcstat(ls, line); + break; + } + case TK_LOCAL: { /* stat -> localstat */ + luaX_next(ls); /* skip LOCAL */ + if (testnext(ls, TK_FUNCTION)) /* local function? */ + localfunc(ls); + else + localstat(ls); + break; + } + case TK_DBCOLON: { /* stat -> label */ + luaX_next(ls); /* skip double colon */ + labelstat(ls, str_checkname(ls), line); + break; + } + case TK_RETURN: { /* stat -> retstat */ + luaX_next(ls); /* skip RETURN */ + retstat(ls); + break; + } + case TK_BREAK: /* stat -> breakstat */ + case TK_GOTO: { /* stat -> 'goto' NAME */ + gotostat(ls, luaK_jump(ls->fs)); + break; + } + default: { /* stat -> func | assignment */ + exprstat(ls); + break; + } + } + lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && + ls->fs->freereg >= ls->fs->nactvar); + ls->fs->freereg = ls->fs->nactvar; /* free registers */ + leavelevel(ls); +} + +/* }====================================================================== */ + + +/* +** compiles the main function, which is a regular vararg function with an +** upvalue named LUA_ENV +*/ +static void mainfunc (LexState *ls, FuncState *fs) { + BlockCnt bl; + expdesc v; + open_func(ls, fs, &bl); + fs->f->is_vararg = 1; /* main function is always vararg */ + init_exp(&v, VLOCAL, 0); /* create and... */ + newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */ + luaX_next(ls); /* read first token */ + statlist(ls); /* parse main body */ + check(ls, TK_EOS); + close_func(ls); +} + + +Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar) { + LexState lexstate; + FuncState funcstate; + Closure *cl = luaF_newLclosure(L, 1); /* create main closure */ + /* anchor closure (to avoid being collected) */ + setclLvalue(L, L->top, cl); + incr_top(L); + funcstate.f = cl->l.p = luaF_newproto(L); + funcstate.f->source = luaS_new(L, name); /* create and anchor TString */ + lexstate.buff = buff; + lexstate.dyd = dyd; + dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; + luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar); + mainfunc(&lexstate, &funcstate); + lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs); + /* all scopes should be correctly finished */ + lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0); + return cl; /* it's on the stack too */ +} + |