forked from KolibriOS/kolibrios
1621 lines
44 KiB
C
1621 lines
44 KiB
C
/*
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** $Id: lparser.c,v 2.124 2011/12/02 13:23:56 roberto Exp $
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** Lua Parser
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** See Copyright Notice in lua.h
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*/
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#include <string.h>
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#define lparser_c
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#define LUA_CORE
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#include "lua.h"
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#include "lcode.h"
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#include "ldebug.h"
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#include "ldo.h"
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#include "lfunc.h"
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#include "llex.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lopcodes.h"
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#include "lparser.h"
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#include "lstate.h"
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#include "lstring.h"
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#include "ltable.h"
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/* maximum number of local variables per function (must be smaller
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than 250, due to the bytecode format) */
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#define MAXVARS 200
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#define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
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/*
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** nodes for block list (list of active blocks)
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*/
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typedef struct BlockCnt {
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struct BlockCnt *previous; /* chain */
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short firstlabel; /* index of first label in this block */
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short firstgoto; /* index of first pending goto in this block */
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lu_byte nactvar; /* # active locals outside the block */
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lu_byte upval; /* true if some variable in the block is an upvalue */
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lu_byte isloop; /* true if `block' is a loop */
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} BlockCnt;
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/*
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** prototypes for recursive non-terminal functions
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*/
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static void statement (LexState *ls);
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static void expr (LexState *ls, expdesc *v);
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static void anchor_token (LexState *ls) {
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/* last token from outer function must be EOS */
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lua_assert(ls->fs != NULL || ls->t.token == TK_EOS);
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if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) {
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TString *ts = ls->t.seminfo.ts;
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luaX_newstring(ls, getstr(ts), ts->tsv.len);
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}
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}
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/* semantic error */
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static l_noret semerror (LexState *ls, const char *msg) {
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ls->t.token = 0; /* remove 'near to' from final message */
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luaX_syntaxerror(ls, msg);
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}
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static l_noret error_expected (LexState *ls, int token) {
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luaX_syntaxerror(ls,
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luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token)));
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}
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static l_noret errorlimit (FuncState *fs, int limit, const char *what) {
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lua_State *L = fs->ls->L;
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const char *msg;
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int line = fs->f->linedefined;
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const char *where = (line == 0)
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? "main function"
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: luaO_pushfstring(L, "function at line %d", line);
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msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s",
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what, limit, where);
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luaX_syntaxerror(fs->ls, msg);
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}
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static void checklimit (FuncState *fs, int v, int l, const char *what) {
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if (v > l) errorlimit(fs, l, what);
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}
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static int testnext (LexState *ls, int c) {
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if (ls->t.token == c) {
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luaX_next(ls);
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return 1;
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}
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else return 0;
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}
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static void check (LexState *ls, int c) {
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if (ls->t.token != c)
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error_expected(ls, c);
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}
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static void checknext (LexState *ls, int c) {
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check(ls, c);
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luaX_next(ls);
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}
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#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); }
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static void check_match (LexState *ls, int what, int who, int where) {
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if (!testnext(ls, what)) {
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if (where == ls->linenumber)
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error_expected(ls, what);
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else {
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luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
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"%s expected (to close %s at line %d)",
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luaX_token2str(ls, what), luaX_token2str(ls, who), where));
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}
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}
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}
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static TString *str_checkname (LexState *ls) {
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TString *ts;
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check(ls, TK_NAME);
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ts = ls->t.seminfo.ts;
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luaX_next(ls);
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return ts;
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}
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static void init_exp (expdesc *e, expkind k, int i) {
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e->f = e->t = NO_JUMP;
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e->k = k;
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e->u.info = i;
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}
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static void codestring (LexState *ls, expdesc *e, TString *s) {
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init_exp(e, VK, luaK_stringK(ls->fs, s));
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}
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static void checkname (LexState *ls, expdesc *e) {
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codestring(ls, e, str_checkname(ls));
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}
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static int registerlocalvar (LexState *ls, TString *varname) {
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FuncState *fs = ls->fs;
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Proto *f = fs->f;
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int oldsize = f->sizelocvars;
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luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
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LocVar, SHRT_MAX, "local variables");
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while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
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f->locvars[fs->nlocvars].varname = varname;
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luaC_objbarrier(ls->L, f, varname);
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return fs->nlocvars++;
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}
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static void new_localvar (LexState *ls, TString *name) {
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FuncState *fs = ls->fs;
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Dyndata *dyd = ls->dyd;
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int reg = registerlocalvar(ls, name);
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checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
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MAXVARS, "local variables");
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luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1,
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dyd->actvar.size, Vardesc, MAX_INT, "local variables");
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dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg);
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}
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static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) {
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new_localvar(ls, luaX_newstring(ls, name, sz));
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}
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#define new_localvarliteral(ls,v) \
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new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1)
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static LocVar *getlocvar (FuncState *fs, int i) {
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int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx;
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lua_assert(idx < fs->nlocvars);
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return &fs->f->locvars[idx];
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}
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static void adjustlocalvars (LexState *ls, int nvars) {
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FuncState *fs = ls->fs;
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fs->nactvar = cast_byte(fs->nactvar + nvars);
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for (; nvars; nvars--) {
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getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc;
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}
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}
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static void removevars (FuncState *fs, int tolevel) {
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fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel);
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while (fs->nactvar > tolevel)
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getlocvar(fs, --fs->nactvar)->endpc = fs->pc;
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}
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static int searchupvalue (FuncState *fs, TString *name) {
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int i;
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Upvaldesc *up = fs->f->upvalues;
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for (i = 0; i < fs->nups; i++) {
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if (eqstr(up[i].name, name)) return i;
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}
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return -1; /* not found */
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}
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static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
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Proto *f = fs->f;
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int oldsize = f->sizeupvalues;
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checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
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luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues,
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Upvaldesc, MAXUPVAL, "upvalues");
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while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL;
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f->upvalues[fs->nups].instack = (v->k == VLOCAL);
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f->upvalues[fs->nups].idx = cast_byte(v->u.info);
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f->upvalues[fs->nups].name = name;
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luaC_objbarrier(fs->ls->L, f, name);
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return fs->nups++;
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}
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static int searchvar (FuncState *fs, TString *n) {
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int i;
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for (i=fs->nactvar-1; i >= 0; i--) {
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if (eqstr(n, getlocvar(fs, i)->varname))
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return i;
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}
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return -1; /* not found */
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}
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/*
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Mark block where variable at given level was defined
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(to emit close instructions later).
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*/
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static void markupval (FuncState *fs, int level) {
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BlockCnt *bl = fs->bl;
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while (bl->nactvar > level) bl = bl->previous;
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bl->upval = 1;
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}
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/*
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Find variable with given name 'n'. If it is an upvalue, add this
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upvalue into all intermediate functions.
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*/
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static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
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if (fs == NULL) /* no more levels? */
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return VVOID; /* default is global */
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else {
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int v = searchvar(fs, n); /* look up locals at current level */
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if (v >= 0) { /* found? */
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init_exp(var, VLOCAL, v); /* variable is local */
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if (!base)
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markupval(fs, v); /* local will be used as an upval */
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return VLOCAL;
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}
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else { /* not found as local at current level; try upvalues */
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int idx = searchupvalue(fs, n); /* try existing upvalues */
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if (idx < 0) { /* not found? */
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if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */
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return VVOID; /* not found; is a global */
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/* else was LOCAL or UPVAL */
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idx = newupvalue(fs, n, var); /* will be a new upvalue */
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}
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init_exp(var, VUPVAL, idx);
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return VUPVAL;
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}
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}
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}
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static void singlevar (LexState *ls, expdesc *var) {
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TString *varname = str_checkname(ls);
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FuncState *fs = ls->fs;
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if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */
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expdesc key;
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singlevaraux(fs, ls->envn, var, 1); /* get environment variable */
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lua_assert(var->k == VLOCAL || var->k == VUPVAL);
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codestring(ls, &key, varname); /* key is variable name */
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luaK_indexed(fs, var, &key); /* env[varname] */
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}
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}
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static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
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FuncState *fs = ls->fs;
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int extra = nvars - nexps;
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if (hasmultret(e->k)) {
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extra++; /* includes call itself */
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if (extra < 0) extra = 0;
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luaK_setreturns(fs, e, extra); /* last exp. provides the difference */
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if (extra > 1) luaK_reserveregs(fs, extra-1);
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}
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else {
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if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */
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if (extra > 0) {
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int reg = fs->freereg;
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luaK_reserveregs(fs, extra);
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luaK_nil(fs, reg, extra);
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}
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}
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}
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static void enterlevel (LexState *ls) {
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lua_State *L = ls->L;
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++L->nCcalls;
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checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
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}
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#define leavelevel(ls) ((ls)->L->nCcalls--)
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static void closegoto (LexState *ls, int g, Labeldesc *label) {
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int i;
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FuncState *fs = ls->fs;
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Labellist *gl = &ls->dyd->gt;
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Labeldesc *gt = &gl->arr[g];
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lua_assert(eqstr(gt->name, label->name));
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if (gt->nactvar < label->nactvar) {
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TString *vname = getlocvar(fs, gt->nactvar)->varname;
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const char *msg = luaO_pushfstring(ls->L,
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"<goto %s> at line %d jumps into the scope of local " LUA_QS,
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getstr(gt->name), gt->line, getstr(vname));
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semerror(ls, msg);
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}
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luaK_patchlist(fs, gt->pc, label->pc);
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/* remove goto from pending list */
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for (i = g; i < gl->n - 1; i++)
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gl->arr[i] = gl->arr[i + 1];
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gl->n--;
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}
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/*
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** try to close a goto with existing labels; this solves backward jumps
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*/
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static int findlabel (LexState *ls, int g) {
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int i;
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BlockCnt *bl = ls->fs->bl;
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Dyndata *dyd = ls->dyd;
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Labeldesc *gt = &dyd->gt.arr[g];
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/* check labels in current block for a match */
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for (i = bl->firstlabel; i < dyd->label.n; i++) {
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Labeldesc *lb = &dyd->label.arr[i];
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if (eqstr(lb->name, gt->name)) { /* correct label? */
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if (gt->nactvar > lb->nactvar &&
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(bl->upval || dyd->label.n > bl->firstlabel))
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luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
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closegoto(ls, g, lb); /* close it */
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return 1;
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}
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}
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return 0; /* label not found; cannot close goto */
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}
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static int newlabelentry (LexState *ls, Labellist *l, TString *name,
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int line, int pc) {
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int n = l->n;
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luaM_growvector(ls->L, l->arr, n, l->size,
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Labeldesc, SHRT_MAX, "labels/gotos");
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l->arr[n].name = name;
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l->arr[n].line = line;
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l->arr[n].nactvar = ls->fs->nactvar;
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l->arr[n].pc = pc;
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l->n++;
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return n;
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}
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/*
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** check whether new label 'lb' matches any pending gotos in current
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** block; solves forward jumps
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*/
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static void findgotos (LexState *ls, Labeldesc *lb) {
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Labellist *gl = &ls->dyd->gt;
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int i = ls->fs->bl->firstgoto;
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while (i < gl->n) {
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if (eqstr(gl->arr[i].name, lb->name))
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closegoto(ls, i, lb);
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else
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i++;
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}
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}
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/*
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** "export" pending gotos to outer level, to check them against
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** outer labels; if the block being exited has upvalues, and
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** the goto exits the scope of any variable (which can be the
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** upvalue), close those variables being exited.
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*/
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static void movegotosout (FuncState *fs, BlockCnt *bl) {
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int i = bl->firstgoto;
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Labellist *gl = &fs->ls->dyd->gt;
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/* correct pending gotos to current block and try to close it
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with visible labels */
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while (i < gl->n) {
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Labeldesc *gt = &gl->arr[i];
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if (gt->nactvar > bl->nactvar) {
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if (bl->upval)
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luaK_patchclose(fs, gt->pc, bl->nactvar);
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gt->nactvar = bl->nactvar;
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}
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if (!findlabel(fs->ls, i))
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i++; /* move to next one */
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}
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}
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static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) {
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bl->isloop = isloop;
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bl->nactvar = fs->nactvar;
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bl->firstlabel = fs->ls->dyd->label.n;
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bl->firstgoto = fs->ls->dyd->gt.n;
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bl->upval = 0;
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bl->previous = fs->bl;
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fs->bl = bl;
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lua_assert(fs->freereg == fs->nactvar);
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}
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/*
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** create a label named "break" to resolve break statements
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*/
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static void breaklabel (LexState *ls) {
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TString *n = luaS_new(ls->L, "break");
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int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc);
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findgotos(ls, &ls->dyd->label.arr[l]);
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}
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/*
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** generates an error for an undefined 'goto'; choose appropriate
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** message when label name is a reserved word (which can only be 'break')
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*/
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static l_noret undefgoto (LexState *ls, Labeldesc *gt) {
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const char *msg = (gt->name->tsv.reserved > 0)
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? "<%s> at line %d not inside a loop"
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: "no visible label " LUA_QS " for <goto> at line %d";
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msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
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semerror(ls, msg);
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}
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static void leaveblock (FuncState *fs) {
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BlockCnt *bl = fs->bl;
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LexState *ls = fs->ls;
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if (bl->previous && bl->upval) {
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/* create a 'jump to here' to close upvalues */
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int j = luaK_jump(fs);
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luaK_patchclose(fs, j, bl->nactvar);
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luaK_patchtohere(fs, j);
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}
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if (bl->isloop)
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breaklabel(ls); /* close pending breaks */
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fs->bl = bl->previous;
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removevars(fs, bl->nactvar);
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lua_assert(bl->nactvar == fs->nactvar);
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fs->freereg = fs->nactvar; /* free registers */
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ls->dyd->label.n = bl->firstlabel; /* remove local labels */
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if (bl->previous) /* inner block? */
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movegotosout(fs, bl); /* update pending gotos to outer block */
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else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
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undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */
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}
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/*
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** adds prototype being created into its parent list of prototypes
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|
** and codes instruction to create new closure
|
|
*/
|
|
static void codeclosure (LexState *ls, Proto *clp, expdesc *v) {
|
|
FuncState *fs = ls->fs->prev;
|
|
Proto *f = fs->f; /* prototype of function creating new closure */
|
|
if (fs->np >= f->sizep) {
|
|
int oldsize = f->sizep;
|
|
luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
|
|
MAXARG_Bx, "functions");
|
|
while (oldsize < f->sizep) f->p[oldsize++] = NULL;
|
|
}
|
|
f->p[fs->np++] = clp;
|
|
luaC_objbarrier(ls->L, f, clp);
|
|
init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
|
|
luaK_exp2nextreg(fs, v); /* fix it at stack top (for GC) */
|
|
}
|
|
|
|
|
|
static void open_func (LexState *ls, FuncState *fs, 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 = luaF_newproto(L);
|
|
fs->f = f;
|
|
f->source = ls->source;
|
|
f->maxstacksize = 2; /* registers 0/1 are always valid */
|
|
/* anchor prototype (to avoid being collected) */
|
|
setptvalue2s(L, L->top, f);
|
|
incr_top(L);
|
|
fs->h = luaH_new(L);
|
|
/* anchor table of constants (to avoid being collected) */
|
|
sethvalue2s(L, L->top, fs->h);
|
|
incr_top(L);
|
|
enterblock(fs, bl, 0);
|
|
}
|
|
|
|
|
|
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);
|
|
L->top--; /* pop prototype (after possible collection) */
|
|
}
|
|
|
|
|
|
/*
|
|
** opens the main function, which is a regular vararg function with an
|
|
** upvalue named LUA_ENV
|
|
*/
|
|
static void open_mainfunc (LexState *ls, FuncState *fs, BlockCnt *bl) {
|
|
expdesc v;
|
|
open_func(ls, fs, bl);
|
|
fs->f->is_vararg = 1; /* main function is always vararg */
|
|
init_exp(&v, VLOCAL, 0);
|
|
newupvalue(fs, ls->envn, &v); /* create environment upvalue */
|
|
}
|
|
|
|
|
|
|
|
/*============================================================*/
|
|
/* 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 = 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;
|
|
open_func(ls, &new_fs, &bl);
|
|
new_fs.f->linedefined = line;
|
|
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, new_fs.f, 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 = 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");
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static void primaryexp (LexState *ls, expdesc *v) {
|
|
/* primaryexp ->
|
|
prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
|
|
FuncState *fs = ls->fs;
|
|
int line = ls->linenumber;
|
|
prefixexp(ls, v);
|
|
for (;;) {
|
|
switch (ls->t.token) {
|
|
case '.': { /* 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 | 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");
|
|
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}, /* ^, .. (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 = 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 = 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 -> `,' primaryexp assignment */
|
|
struct LHS_assign nv;
|
|
nv.prev = lh;
|
|
primaryexp(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 -= 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 (eqstr(label, ll->arr[i].name)) {
|
|
const char *msg = luaO_pushfstring(fs->ls->L,
|
|
"label " LUA_QS " already defined on line %d",
|
|
getstr(label), ll->arr[i].line);
|
|
semerror(fs->ls, msg);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static void labelstat (LexState *ls, TString *label, int line) {
|
|
/* label -> '::' NAME '::' */
|
|
FuncState *fs = ls->fs;
|
|
Labellist *ll = &ls->dyd->label;
|
|
int l; /* index of new label being created */
|
|
checkrepeated(fs, ll, label); /* check for repeated labels */
|
|
checknext(ls, TK_DBCOLON); /* skip double colon */
|
|
/* create new entry for this label */
|
|
l = newlabelentry(ls, ll, label, line, fs->pc);
|
|
/* skip other no-op statements */
|
|
while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
|
|
statement(ls);
|
|
if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */
|
|
/* assume that locals are already out of scope */
|
|
ll->arr[l].nactvar = fs->bl->nactvar;
|
|
}
|
|
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 */
|
|
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;
|
|
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 */
|
|
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);
|
|
}
|
|
|
|
/* }====================================================================== */
|
|
|
|
|
|
Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
|
|
Dyndata *dyd, const char *name, int firstchar) {
|
|
LexState lexstate;
|
|
FuncState funcstate;
|
|
BlockCnt bl;
|
|
TString *tname = luaS_new(L, name);
|
|
setsvalue2s(L, L->top, tname); /* push name to protect it */
|
|
incr_top(L);
|
|
lexstate.buff = buff;
|
|
lexstate.dyd = dyd;
|
|
dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
|
|
luaX_setinput(L, &lexstate, z, tname, firstchar);
|
|
open_mainfunc(&lexstate, &funcstate, &bl);
|
|
luaX_next(&lexstate); /* read first token */
|
|
statlist(&lexstate); /* main body */
|
|
check(&lexstate, TK_EOS);
|
|
close_func(&lexstate);
|
|
L->top--; /* pop name */
|
|
lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
|
|
/* all scopes should be correctly finished */
|
|
lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
|
|
return funcstate.f;
|
|
}
|
|
|