summaryrefslogtreecommitdiff
path: root/src/lparser.c
diff options
context:
space:
mode:
authorLua Team <team@lua.org>1998-07-11 12:00:00 +0000
committerrepogen <>1998-07-11 12:00:00 +0000
commit377347776f1f3d820f92151f70bec667f96d5e6b (patch)
treecdb3ba26158df33547dfe765547177afcee119d1 /src/lparser.c
parent4f8c5d0f284e1f4da717aea5008915f185cd2e05 (diff)
downloadlua-github-377347776f1f3d820f92151f70bec667f96d5e6b.tar.gz
Lua 3.13.1
Diffstat (limited to 'src/lparser.c')
-rw-r--r--src/lparser.c1333
1 files changed, 1333 insertions, 0 deletions
diff --git a/src/lparser.c b/src/lparser.c
new file mode 100644
index 00000000..9b37d9df
--- /dev/null
+++ b/src/lparser.c
@@ -0,0 +1,1333 @@
+/*
+** $Id: lparser.c,v 1.3 1998/07/06 22:07:51 roberto Exp $
+** LL(1) Parser and code generator for Lua
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdio.h>
+
+#include "lauxlib.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "llex.h"
+#include "lmem.h"
+#include "lopcodes.h"
+#include "lparser.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "lua.h"
+#include "luadebug.h"
+#include "lzio.h"
+
+
+/* for limit numbers in error messages */
+#define MES_LIM(x) "(limit=" x ")"
+
+
+/* size of a "normal" jump instruction: OpCode + 1 byte */
+#define JMPSIZE 2
+
+/* maximum number of local variables */
+#define MAXLOCALS 32
+#define SMAXLOCALS "32"
+
+
+/* maximum number of upvalues */
+#define MAXUPVALUES 16
+#define SMAXUPVALUES "16"
+
+
+/*
+** Variable descriptor:
+** must include a "exp" option because LL(1) cannot distinguish
+** between variables, upvalues and function calls on first sight.
+** VGLOBAL: info is constant index of global name
+** VLOCAL: info is stack index
+** VDOT: info is constant index of index name
+** VEXP: info is pc index of "nparam" of function call (or 0 if exp is closed)
+*/
+typedef enum {VGLOBAL, VLOCAL, VDOT, VINDEXED, VEXP} varkind;
+
+typedef struct {
+ varkind k;
+ int info;
+} vardesc;
+
+
+/*
+** Expression List descriptor:
+** tells number of expressions in the list,
+** and, if last expression is open (a function call),
+** where is its pc index of "nparam"
+*/
+typedef struct {
+ int n;
+ int pc; /* 0 if last expression is closed */
+} listdesc;
+
+
+/*
+** Constructors descriptor:
+** "n" indicates number of elements, and "k" signals whether
+** it is a list constructor (k = 0) or a record constructor (k = 1)
+** or empty (k = ';' or '}')
+*/
+typedef struct {
+ int n;
+ int k;
+} constdesc;
+
+
+/* state needed to generate code for a given function */
+typedef struct FuncState {
+ TProtoFunc *f; /* current function header */
+ struct FuncState *prev; /* enclosuring function */
+ int pc; /* next position to code */
+ int stacksize; /* number of values on activation register */
+ int maxstacksize; /* maximum number of values on activation register */
+ int nlocalvar; /* number of active local variables */
+ int nupvalues; /* number of upvalues */
+ int nvars; /* number of entries in f->locvars */
+ int maxcode; /* size of f->code */
+ int maxvars; /* size of f->locvars (-1 if no debug information) */
+ int maxconsts; /* size of f->consts */
+ int lastsetline; /* line where last SETLINE was issued */
+ vardesc upvalues[MAXUPVALUES]; /* upvalues */
+ TaggedString *localvar[MAXLOCALS]; /* store local variable names */
+} FuncState;
+
+
+static int assignment (LexState *ls, vardesc *v, int nvars);
+static int cond (LexState *ls);
+static int funcname (LexState *ls, vardesc *v);
+static int funcparams (LexState *ls, int slf);
+static int listfields (LexState *ls);
+static int localnamelist (LexState *ls);
+static int optional (LexState *ls, int c);
+static int recfields (LexState *ls);
+static int stat (LexState *ls);
+static void block (LexState *ls);
+static void body (LexState *ls, int needself, int line);
+static void chunk (LexState *ls);
+static void constructor (LexState *ls);
+static void decinit (LexState *ls, listdesc *d);
+static void exp0 (LexState *ls, vardesc *v);
+static void exp1 (LexState *ls);
+static void exp2 (LexState *ls, vardesc *v);
+static void explist (LexState *ls, listdesc *e);
+static void explist1 (LexState *ls, listdesc *e);
+static void ifpart (LexState *ls);
+static void parlist (LexState *ls);
+static void part (LexState *ls, constdesc *cd);
+static void recfield (LexState *ls);
+static void ret (LexState *ls);
+static void simpleexp (LexState *ls, vardesc *v);
+static void statlist (LexState *ls);
+static void var_or_func (LexState *ls, vardesc *v);
+static void var_or_func_tail (LexState *ls, vardesc *v);
+
+
+
+static void check_pc (FuncState *fs, int n) {
+ if (fs->pc+n > fs->maxcode)
+ fs->maxcode = luaM_growvector(&fs->f->code, fs->maxcode,
+ Byte, codeEM, MAX_INT);
+}
+
+
+static void code_byte (FuncState *fs, Byte c) {
+ check_pc(fs, 1);
+ fs->f->code[fs->pc++] = c;
+}
+
+
+static void deltastack (LexState *ls, int delta) {
+ FuncState *fs = ls->fs;
+ fs->stacksize += delta;
+ if (fs->stacksize > fs->maxstacksize) {
+ if (fs->stacksize > 255)
+ luaX_error(ls, "function/expression too complex");
+ fs->maxstacksize = fs->stacksize;
+ }
+}
+
+
+static int code_oparg_at (LexState *ls, int pc, OpCode op, int builtin,
+ int arg, int delta) {
+ Byte *code = ls->fs->f->code;
+ deltastack(ls, delta);
+ if (arg < builtin) {
+ code[pc] = op+1+arg;
+ return 1;
+ }
+ else if (arg <= 255) {
+ code[pc] = op;
+ code[pc+1] = arg;
+ return 2;
+ }
+ else if (arg <= MAX_WORD) {
+ code[pc] = op+1+builtin;
+ code[pc+1] = arg>>8;
+ code[pc+2] = arg&0xFF;
+ return 3;
+ }
+ else luaX_error(ls, "code too long " MES_LIM("64K"));
+ return 0; /* to avoid warnings */
+}
+
+
+static int fix_opcode (LexState *ls, int pc, OpCode op, int builtin, int arg) {
+ FuncState *fs = ls->fs;
+ TProtoFunc *f = fs->f;
+ if (arg < builtin) { /* close space */
+ luaO_memdown(f->code+pc+1, f->code+pc+2, fs->pc-(pc+2));
+ fs->pc--;
+ }
+ else if (arg > 255) { /* open space */
+ check_pc(fs, 1);
+ luaO_memup(f->code+pc+1, f->code+pc, fs->pc-pc);
+ fs->pc++;
+ }
+ return code_oparg_at(ls, pc, op, builtin, arg, 0) - 2;
+}
+
+static void code_oparg (LexState *ls, OpCode op, int builtin, int arg,
+ int delta) {
+ check_pc(ls->fs, 3); /* maximum code size */
+ ls->fs->pc += code_oparg_at(ls, ls->fs->pc, op, builtin, arg, delta);
+}
+
+
+static void code_opcode (LexState *ls, OpCode op, int delta) {
+ deltastack(ls, delta);
+ code_byte(ls->fs, op);
+}
+
+
+static void code_constant (LexState *ls, int c) {
+ code_oparg(ls, PUSHCONSTANT, 8, c, 1);
+}
+
+
+static int next_constant (FuncState *fs) {
+ TProtoFunc *f = fs->f;
+ if (f->nconsts >= fs->maxconsts) {
+ fs->maxconsts = luaM_growvector(&f->consts, fs->maxconsts, TObject,
+ constantEM, MAX_WORD);
+ }
+ return f->nconsts++;
+}
+
+
+static int string_constant (FuncState *fs, TaggedString *s) {
+ TProtoFunc *f = fs->f;
+ int c = s->constindex;
+ if (!(c < f->nconsts &&
+ ttype(&f->consts[c]) == LUA_T_STRING && tsvalue(&f->consts[c]) == s)) {
+ c = next_constant(fs);
+ ttype(&f->consts[c]) = LUA_T_STRING;
+ tsvalue(&f->consts[c]) = s;
+ s->constindex = c; /* hint for next time */
+ }
+ return c;
+}
+
+
+static void code_string (LexState *ls, TaggedString *s) {
+ code_constant(ls, string_constant(ls->fs, s));
+}
+
+
+#define LIM 20
+static int real_constant (FuncState *fs, real r) {
+ /* check whether 'r' has appeared within the last LIM entries */
+ TObject *cnt = fs->f->consts;
+ int c = fs->f->nconsts;
+ int lim = c < LIM ? 0 : c-LIM;
+ while (--c >= lim) {
+ if (ttype(&cnt[c]) == LUA_T_NUMBER && nvalue(&cnt[c]) == r)
+ return c;
+ }
+ /* not found; create a luaM_new entry */
+ c = next_constant(fs);
+ cnt = fs->f->consts; /* 'next_constant' may reallocate this vector */
+ ttype(&cnt[c]) = LUA_T_NUMBER;
+ nvalue(&cnt[c]) = r;
+ return c;
+}
+
+
+static void code_number (LexState *ls, real f) {
+ int i;
+ if (f >= 0 && f <= (real)MAX_WORD && (real)(i=(int)f) == f)
+ code_oparg(ls, PUSHNUMBER, 3, i, 1); /* f has a short integer value */
+ else
+ code_constant(ls, real_constant(ls->fs, f));
+}
+
+
+static void flush_record (LexState *ls, int n) {
+ if (n > 0)
+ code_oparg(ls, SETMAP, 1, n-1, -2*n);
+}
+
+
+static void flush_list (LexState *ls, int m, int n) {
+ if (n == 0) return;
+ code_oparg(ls, SETLIST, 1, m, -n);
+ code_byte(ls->fs, n);
+}
+
+
+static void luaI_registerlocalvar (FuncState *fs, TaggedString *varname,
+ int line) {
+ if (fs->maxvars != -1) { /* debug information? */
+ TProtoFunc *f = fs->f;
+ if (fs->nvars >= fs->maxvars)
+ fs->maxvars = luaM_growvector(&f->locvars, fs->maxvars,
+ LocVar, "", MAX_WORD);
+ f->locvars[fs->nvars].varname = varname;
+ f->locvars[fs->nvars].line = line;
+ fs->nvars++;
+ }
+}
+
+
+static void luaI_unregisterlocalvar (FuncState *fs, int line) {
+ luaI_registerlocalvar(fs, NULL, line);
+}
+
+
+static void store_localvar (LexState *ls, TaggedString *name, int n) {
+ FuncState *fs = ls->fs;
+ if (fs->nlocalvar+n < MAXLOCALS)
+ fs->localvar[fs->nlocalvar+n] = name;
+ else
+ luaX_error(ls, "too many local variables " MES_LIM(SMAXLOCALS));
+ luaI_registerlocalvar(fs, name, ls->linenumber);
+}
+
+
+static void add_localvar (LexState *ls, TaggedString *name) {
+ store_localvar(ls, name, 0);
+ ls->fs->nlocalvar++;
+}
+
+
+static int aux_localname (FuncState *fs, TaggedString *n) {
+ int i;
+ for (i=fs->nlocalvar-1; i >= 0; i--)
+ if (n == fs->localvar[i]) return i; /* local var index */
+ return -1; /* not found */
+}
+
+
+static void singlevar (LexState *ls, TaggedString *n, vardesc *var, int prev) {
+ FuncState *fs = prev ? ls->fs->prev : ls->fs;
+ int i = aux_localname(fs, n);
+ if (i >= 0) { /* local value */
+ var->k = VLOCAL;
+ var->info = i;
+ }
+ else { /* check shadowing */
+ FuncState *level = fs;
+ while ((level = level->prev) != NULL)
+ if (aux_localname(level, n) >= 0)
+ luaX_syntaxerror(ls, "cannot access a variable in outer scope", n->str);
+ var->k = VGLOBAL;
+ var->info = string_constant(fs, n);
+ }
+}
+
+
+static int indexupvalue (LexState *ls, TaggedString *n) {
+ FuncState *fs = ls->fs;
+ vardesc v;
+ int i;
+ singlevar(ls, n, &v, 1);
+ for (i=0; i<fs->nupvalues; i++) {
+ if (fs->upvalues[i].k == v.k && fs->upvalues[i].info == v.info)
+ return i;
+ }
+ /* new one */
+ if (++(fs->nupvalues) > MAXUPVALUES)
+ luaX_error(ls, "too many upvalues in a single function "
+ MES_LIM(SMAXUPVALUES));
+ fs->upvalues[i] = v; /* i = fs->nupvalues - 1 */
+ return i;
+}
+
+
+static void pushupvalue (LexState *ls, TaggedString *n) {
+ int i;
+ if (ls->fs->prev == NULL)
+ luaX_syntaxerror(ls, "cannot access upvalue in main", n->str);
+ if (aux_localname(ls->fs, n) >= 0)
+ luaX_syntaxerror(ls, "cannot access an upvalue in current scope", n->str);
+ i = indexupvalue(ls, n);
+ code_oparg(ls, PUSHUPVALUE, 2, i, 1);
+}
+
+
+
+static void check_debugline (LexState *ls) {
+ if (lua_debug && ls->linenumber != ls->fs->lastsetline) {
+ code_oparg(ls, SETLINE, 0, ls->linenumber, 0);
+ ls->fs->lastsetline = ls->linenumber;
+ }
+}
+
+
+static void adjuststack (LexState *ls, int n) {
+ if (n > 0)
+ code_oparg(ls, POP, 2, n-1, -n);
+ else if (n < 0)
+ code_oparg(ls, PUSHNIL, 1, (-n)-1, -n);
+}
+
+
+static void close_exp (LexState *ls, int pc, int nresults) {
+ if (pc > 0) { /* expression is an open function call */
+ Byte *code = ls->fs->f->code;
+ int nparams = code[pc]; /* save nparams */
+ pc += fix_opcode(ls, pc-2, CALLFUNC, 2, nresults);
+ code[pc] = nparams; /* restore nparams */
+ if (nresults != MULT_RET)
+ deltastack(ls, nresults); /* "push" results */
+ deltastack(ls, -(nparams+1)); /* "pop" params and function */
+ }
+}
+
+
+static void adjust_mult_assign (LexState *ls, int nvars, listdesc *d) {
+ int diff = d->n - nvars;
+ if (d->pc == 0) { /* list is closed */
+ /* push or pop eventual difference between list lengths */
+ adjuststack(ls, diff);
+ }
+ else { /* must correct function call */
+ diff--; /* do not count function call itself */
+ if (diff < 0) { /* more variables than values */
+ /* function call must provide extra values */
+ close_exp(ls, d->pc, -diff);
+ }
+ else { /* more values than variables */
+ close_exp(ls, d->pc, 0); /* call should provide no value */
+ adjuststack(ls, diff); /* pop eventual extra values */
+ }
+ }
+}
+
+
+static void code_args (LexState *ls, int nparams, int dots) {
+ FuncState *fs = ls->fs;
+ fs->nlocalvar += nparams; /* "self" may already be there */
+ nparams = fs->nlocalvar;
+ if (!dots) {
+ fs->f->code[1] = nparams; /* fill-in arg information */
+ deltastack(ls, nparams);
+ }
+ else {
+ fs->f->code[1] = nparams+ZEROVARARG;
+ deltastack(ls, nparams+1);
+ add_localvar(ls, luaS_new("arg"));
+ }
+}
+
+
+static void lua_pushvar (LexState *ls, vardesc *var) {
+ switch (var->k) {
+ case VLOCAL:
+ code_oparg(ls, PUSHLOCAL, 8, var->info, 1);
+ break;
+ case VGLOBAL:
+ code_oparg(ls, GETGLOBAL, 8, var->info, 1);
+ break;
+ case VDOT:
+ code_oparg(ls, GETDOTTED, 8, var->info, 0);
+ break;
+ case VINDEXED:
+ code_opcode(ls, GETTABLE, -1);
+ break;
+ case VEXP:
+ close_exp(ls, var->info, 1); /* function must return 1 value */
+ break;
+ }
+ var->k = VEXP;
+ var->info = 0; /* now this is a closed expression */
+}
+
+
+static void storevar (LexState *ls, vardesc *var) {
+ switch (var->k) {
+ case VLOCAL:
+ code_oparg(ls, SETLOCAL, 8, var->info, -1);
+ break;
+ case VGLOBAL:
+ code_oparg(ls, SETGLOBAL, 8, var->info, -1);
+ break;
+ case VINDEXED:
+ code_opcode(ls, SETTABLE0, -3);
+ break;
+ default:
+ LUA_INTERNALERROR("invalid var kind to store");
+ }
+}
+
+
+static int fix_jump (LexState *ls, int pc, OpCode op, int n) {
+ /* jump is relative to position following jump instruction */
+ return fix_opcode(ls, pc, op, 0, n-(pc+JMPSIZE));
+}
+
+
+static void fix_upjmp (LexState *ls, OpCode op, int pos) {
+ int delta = ls->fs->pc+JMPSIZE - pos; /* jump is relative */
+ if (delta > 255) delta++;
+ code_oparg(ls, op, 0, delta, 0);
+}
+
+
+static void codeIf (LexState *ls, int thenAdd, int elseAdd) {
+ FuncState *fs = ls->fs;
+ int elseinit = elseAdd+JMPSIZE;
+ if (fs->pc == elseinit) { /* no else part */
+ fs->pc -= JMPSIZE;
+ elseinit = fs->pc;
+ }
+ else
+ elseinit += fix_jump(ls, elseAdd, JMP, fs->pc);
+ fix_jump(ls, thenAdd, IFFJMP, elseinit);
+}
+
+
+static void func_onstack (LexState *ls, FuncState *func) {
+ FuncState *fs = ls->fs;
+ int i;
+ int c = next_constant(fs);
+ ttype(&fs->f->consts[c]) = LUA_T_PROTO;
+ fs->f->consts[c].value.tf = func->f;
+ if (func->nupvalues == 0)
+ code_constant(ls, c);
+ else {
+ for (i=0; i<func->nupvalues; i++)
+ lua_pushvar(ls, &func->upvalues[i]);
+ code_oparg(ls, CLOSURE, 0, c, -func->nupvalues+1);
+ code_byte(fs, func->nupvalues);
+ }
+}
+
+
+static void init_state (LexState *ls, FuncState *fs, TaggedString *filename) {
+ TProtoFunc *f = luaF_newproto();
+ fs->prev = ls->fs; /* linked list of funcstates */
+ ls->fs = fs;
+ fs->stacksize = 0;
+ fs->maxstacksize = 0;
+ fs->nlocalvar = 0;
+ fs->nupvalues = 0;
+ fs->lastsetline = 0;
+ fs->f = f;
+ f->fileName = filename;
+ fs->pc = 0;
+ fs->maxcode = 0;
+ f->code = NULL;
+ fs->maxconsts = 0;
+ if (lua_debug)
+ fs->nvars = fs->maxvars = 0;
+ else
+ fs->maxvars = -1; /* flag no debug information */
+ code_byte(fs, 0); /* to be filled with stacksize */
+ code_byte(fs, 0); /* to be filled with arg information */
+}
+
+
+static void close_func (LexState *ls) {
+ FuncState *fs = ls->fs;
+ TProtoFunc *f = fs->f;
+ code_opcode(ls, ENDCODE, 0);
+ f->code[0] = fs->maxstacksize;
+ f->code = luaM_reallocvector(f->code, fs->pc, Byte);
+ f->consts = luaM_reallocvector(f->consts, f->nconsts, TObject);
+ if (fs->maxvars != -1) { /* debug information? */
+ luaI_registerlocalvar(fs, NULL, -1); /* flag end of vector */
+ f->locvars = luaM_reallocvector(f->locvars, fs->nvars, LocVar);
+ }
+ ls->fs = fs->prev;
+}
+
+
+
+static int expfollow [] = {ELSE, ELSEIF, THEN, IF, WHILE, REPEAT, DO, NAME,
+ LOCAL, FUNCTION, END, UNTIL, RETURN, ')', ']', '}', ';', EOS, ',', 0};
+
+static int is_in (int tok, int *toks) {
+ int *t = toks;
+ while (*t) {
+ if (*t == tok)
+ return t-toks;
+ t++;
+ }
+ return -1;
+}
+
+
+static void next (LexState *ls) {
+ ls->token = luaX_lex(ls);
+}
+
+
+static void error_expected (LexState *ls, int token) {
+ char buff[100], t[TOKEN_LEN];
+ luaX_token2str(ls, token, t);
+ sprintf(buff, "`%s' expected", t);
+ luaX_error(ls, buff);
+}
+
+static void error_unmatched (LexState *ls, int what, int who, int where) {
+ if (where == ls->linenumber)
+ error_expected(ls, what);
+ else {
+ char buff[100];
+ char t_what[TOKEN_LEN], t_who[TOKEN_LEN];
+ luaX_token2str(ls, what, t_what);
+ luaX_token2str(ls, who, t_who);
+ sprintf(buff, "`%s' expected (to close `%s' at line %d)",
+ t_what, t_who, where);
+ luaX_error(ls, buff);
+ }
+}
+
+static void check (LexState *ls, int c) {
+ if (ls->token != c)
+ error_expected(ls, c);
+ next(ls);
+}
+
+static void check_match (LexState *ls, int what, int who, int where) {
+ if (ls->token != what)
+ error_unmatched(ls, what, who, where);
+ check_debugline(ls); /* to 'mark' the 'what' */
+ next(ls);
+}
+
+static TaggedString *checkname (LexState *ls) {
+ TaggedString *ts;
+ if (ls->token != NAME)
+ luaX_error(ls, "`NAME' expected");
+ ts = ls->seminfo.ts;
+ next(ls);
+ return ts;
+}
+
+
+static int optional (LexState *ls, int c) {
+ if (ls->token == c) {
+ next(ls);
+ return 1;
+ }
+ else return 0;
+}
+
+
+TProtoFunc *luaY_parser (ZIO *z) {
+ struct LexState lexstate;
+ struct FuncState funcstate;
+ luaX_setinput(&lexstate, z);
+ init_state(&lexstate, &funcstate, luaS_new(zname(z)));
+ next(&lexstate); /* read first token */
+ chunk(&lexstate);
+ if (lexstate.token != EOS)
+ luaX_error(&lexstate, "<eof> expected");
+ close_func(&lexstate);
+ return funcstate.f;
+}
+
+
+
+/*============================================================*/
+/* GRAMAR RULES */
+/*============================================================*/
+
+static void chunk (LexState *ls) {
+ /* chunk -> statlist ret */
+ statlist(ls);
+ ret(ls);
+}
+
+static void statlist (LexState *ls) {
+ /* statlist -> { stat [;] } */
+ while (stat(ls)) {
+ LUA_ASSERT(ls->fs->stacksize == ls->fs->nlocalvar,
+ "stack size != # local vars");
+ optional(ls, ';');
+ }
+}
+
+static int stat (LexState *ls) {
+ int line = ls->linenumber; /* may be needed for error messages */
+ FuncState *fs = ls->fs;
+ switch (ls->token) {
+ case IF: { /* stat -> IF ifpart END */
+ next(ls);
+ ifpart(ls);
+ check_match(ls, END, IF, line);
+ return 1;
+ }
+
+ case WHILE: { /* stat -> WHILE cond DO block END */
+ TProtoFunc *f = fs->f;
+ int while_init = fs->pc;
+ int cond_end, cond_size;
+ next(ls);
+ cond_end = cond(ls);
+ check(ls, DO);
+ block(ls);
+ check_match(ls, END, WHILE, line);
+ cond_size = cond_end-while_init;
+ check_pc(fs, cond_size);
+ memcpy(f->code+fs->pc, f->code+while_init, cond_size);
+ luaO_memdown(f->code+while_init, f->code+cond_end, fs->pc-while_init);
+ while_init += JMPSIZE + fix_jump(ls, while_init, JMP, fs->pc-cond_size);
+ fix_upjmp(ls, IFTUPJMP, while_init);
+ return 1;
+ }
+
+ case DO: { /* stat -> DO block END */
+ next(ls);
+ block(ls);
+ check_match(ls, END, DO, line);
+ return 1;
+ }
+
+ case REPEAT: { /* stat -> REPEAT block UNTIL exp1 */
+ int repeat_init = fs->pc;
+ next(ls);
+ block(ls);
+ check_match(ls, UNTIL, REPEAT, line);
+ exp1(ls);
+ fix_upjmp(ls, IFFUPJMP, repeat_init);
+ deltastack(ls, -1); /* pops condition */
+ return 1;
+ }
+
+ case FUNCTION: { /* stat -> FUNCTION funcname body */
+ int needself;
+ vardesc v;
+ if (ls->fs->prev) /* inside other function? */
+ return 0;
+ check_debugline(ls);
+ next(ls);
+ needself = funcname(ls, &v);
+ body(ls, needself, line);
+ storevar(ls, &v);
+ return 1;
+ }
+
+ case LOCAL: { /* stat -> LOCAL localnamelist decinit */
+ listdesc d;
+ int nvars;
+ check_debugline(ls);
+ next(ls);
+ nvars = localnamelist(ls);
+ decinit(ls, &d);
+ ls->fs->nlocalvar += nvars;
+ adjust_mult_assign(ls, nvars, &d);
+ return 1;
+ }
+
+ case NAME: case '%': { /* stat -> func | ['%'] NAME assignment */
+ vardesc v;
+ check_debugline(ls);
+ var_or_func(ls, &v);
+ if (v.k == VEXP) { /* stat -> func */
+ if (v.info == 0) /* is just an upper value? */
+ luaX_error(ls, "syntax error");
+ close_exp(ls, v.info, 0);
+ }
+ else {
+ int left = assignment(ls, &v, 1); /* stat -> ['%'] NAME assignment */
+ adjuststack(ls, left); /* remove eventual 'garbage' left on stack */
+ }
+ return 1;
+ }
+
+ case RETURN: case ';': case ELSE: case ELSEIF:
+ case END: case UNTIL: case EOS: /* 'stat' follow */
+ return 0;
+
+ default:
+ luaX_error(ls, "<statement> expected");
+ return 0; /* to avoid warnings */
+ }
+}
+
+static int SaveWord (LexState *ls) {
+ int res = ls->fs->pc;
+ check_pc(ls->fs, JMPSIZE);
+ ls->fs->pc += JMPSIZE; /* open space */
+ return res;
+}
+
+static int SaveWordPop (LexState *ls) {
+ deltastack(ls, -1); /* pop condition */
+ return SaveWord(ls);
+}
+
+static int cond (LexState *ls) {
+ /* cond -> exp1 */
+ exp1(ls);
+ return SaveWordPop(ls);
+}
+
+static void block (LexState *ls) {
+ /* block -> chunk */
+ FuncState *fs = ls->fs;
+ int nlocalvar = fs->nlocalvar;
+ chunk(ls);
+ adjuststack(ls, fs->nlocalvar - nlocalvar);
+ for (; fs->nlocalvar > nlocalvar; fs->nlocalvar--)
+ luaI_unregisterlocalvar(fs, ls->linenumber);
+}
+
+static int funcname (LexState *ls, vardesc *v) {
+ /* funcname -> NAME [':' NAME | '.' NAME] */
+ int needself = 0;
+ singlevar(ls, checkname(ls), v, 0);
+ if (ls->token == ':' || ls->token == '.') {
+ needself = (ls->token == ':');
+ next(ls);
+ lua_pushvar(ls, v);
+ code_string(ls, checkname(ls));
+ v->k = VINDEXED;
+ }
+ return needself;
+}
+
+static void body (LexState *ls, int needself, int line) {
+ /* body -> '(' parlist ')' chunk END */
+ FuncState newfs;
+ init_state(ls, &newfs, ls->fs->f->fileName);
+ newfs.f->lineDefined = line;
+ check(ls, '(');
+ if (needself)
+ add_localvar(ls, luaS_new("self"));
+ parlist(ls);
+ check(ls, ')');
+ chunk(ls);
+ check_match(ls, END, FUNCTION, line);
+ close_func(ls);
+ func_onstack(ls, &newfs);
+}
+
+static void ifpart (LexState *ls) {
+ /* ifpart -> cond THEN block [ELSE block | ELSEIF ifpart] */
+ int c = cond(ls);
+ int e;
+ check(ls, THEN);
+ block(ls);
+ e = SaveWord(ls);
+ switch (ls->token) {
+ case ELSE:
+ next(ls);
+ block(ls);
+ break;
+
+ case ELSEIF:
+ next(ls);
+ ifpart(ls);
+ break;
+ }
+ codeIf(ls, c, e);
+}
+
+static void ret (LexState *ls) {
+ /* ret -> [RETURN explist sc] */
+ if (ls->token == RETURN) {
+ listdesc e;
+ check_debugline(ls);
+ next(ls);
+ explist(ls, &e);
+ close_exp(ls, e.pc, MULT_RET);
+ code_oparg(ls, RETCODE, 0, ls->fs->nlocalvar, 0);
+ ls->fs->stacksize = ls->fs->nlocalvar; /* removes all temp values */
+ optional(ls, ';');
+ }
+}
+
+
+/*
+** For parsing expressions, we use a classic stack with priorities.
+** Each binary operator is represented by its index in "binop" + FIRSTBIN
+** (EQ=2, NE=3, ... '^'=13). The unary NOT is 0 and UNMINUS is 1.
+*/
+
+/* code of first binary operator */
+#define FIRSTBIN 2
+
+/* code for power operator (last operator)
+** '^' needs special treatment because it is right associative
+*/
+#define POW 13
+
+static int binop [] = {EQ, NE, '>', '<', LE, GE, CONC,
+ '+', '-', '*', '/', '^', 0};
+
+static int priority [POW+1] = {5, 5, 1, 1, 1, 1, 1, 1, 2, 3, 3, 4, 4, 6};
+
+static OpCode opcodes [POW+1] = {NOTOP, MINUSOP, EQOP, NEQOP, GTOP, LTOP,
+ LEOP, GEOP, CONCOP, ADDOP, SUBOP, MULTOP, DIVOP, POWOP};
+
+#define MAXOPS 20
+
+typedef struct {
+ int ops[MAXOPS];
+ int top;
+} stack_op;
+
+
+static void exp1 (LexState *ls) {
+ vardesc v;
+ exp0(ls, &v);
+ lua_pushvar(ls, &v);
+ if (is_in(ls->token, expfollow) < 0)
+ luaX_error(ls, "ill formed expression");
+}
+
+
+static void exp0 (LexState *ls, vardesc *v) {
+ exp2(ls, v);
+ while (ls->token == AND || ls->token == OR) {
+ int is_and = (ls->token == AND);
+ int pc;
+ lua_pushvar(ls, v);
+ next(ls);
+ pc = SaveWordPop(ls);
+ exp2(ls, v);
+ lua_pushvar(ls, v);
+ fix_jump(ls, pc, (is_and?ONFJMP:ONTJMP), ls->fs->pc);
+ }
+}
+
+
+static void push (LexState *ls, stack_op *s, int op) {
+ if (s->top == MAXOPS)
+ luaX_error(ls, "expression too complex");
+ s->ops[s->top++] = op;
+}
+
+
+static void prefix (LexState *ls, stack_op *s) {
+ while (ls->token == NOT || ls->token == '-') {
+ push(ls, s, ls->token==NOT?0:1);
+ next(ls);
+ }
+}
+
+static void pop_to (LexState *ls, stack_op *s, int prio) {
+ int op;
+ while (s->top > 0 && priority[(op=s->ops[s->top-1])] >= prio) {
+ code_opcode(ls, opcodes[op], op<FIRSTBIN?0:-1);
+ s->top--;
+ }
+}
+
+static void exp2 (LexState *ls, vardesc *v) {
+ stack_op s;
+ int op;
+ s.top = 0;
+ prefix(ls, &s);
+ simpleexp(ls, v);
+ while ((op = is_in(ls->token, binop)) >= 0) {
+ op += FIRSTBIN;
+ lua_pushvar(ls, v);
+ /* '^' is right associative, so must 'simulate' a higher priority */
+ pop_to(ls, &s, (op == POW)?priority[op]+1:priority[op]);
+ push(ls, &s, op);
+ next(ls);
+ prefix(ls, &s);
+ simpleexp(ls, v);
+ lua_pushvar(ls, v);
+ }
+ if (s.top > 0) {
+ lua_pushvar(ls, v);
+ pop_to(ls, &s, 0);
+ }
+}
+
+
+static void simpleexp (LexState *ls, vardesc *v) {
+ check_debugline(ls);
+ switch (ls->token) {
+ case '(': /* simpleexp -> '(' exp0 ')' */
+ next(ls);
+ exp0(ls, v);
+ check(ls, ')');
+ break;
+
+ case NUMBER: /* simpleexp -> NUMBER */
+ code_number(ls, ls->seminfo.r);
+ next(ls);
+ v->k = VEXP; v->info = 0;
+ break;
+
+ case STRING: /* simpleexp -> STRING */
+ code_string(ls, ls->seminfo.ts);
+ next(ls);
+ v->k = VEXP; v->info = 0;
+ break;
+
+ case NIL: /* simpleexp -> NIL */
+ adjuststack(ls, -1);
+ next(ls);
+ v->k = VEXP; v->info = 0;
+ break;
+
+ case '{': /* simpleexp -> constructor */
+ constructor(ls);
+ v->k = VEXP; v->info = 0;
+ break;
+
+ case FUNCTION: { /* simpleexp -> FUNCTION body */
+ int line = ls->linenumber;
+ next(ls);
+ body(ls, 0, line);
+ v->k = VEXP; v->info = 0;
+ break;
+ }
+
+ case NAME: case '%':
+ var_or_func(ls, v);
+ break;
+
+ default:
+ luaX_error(ls, "<expression> expected");
+ break;
+ }
+}
+
+static void var_or_func (LexState *ls, vardesc *v) {
+ /* var_or_func -> ['%'] NAME var_or_func_tail */
+ if (optional(ls, '%')) { /* upvalue? */
+ pushupvalue(ls, checkname(ls));
+ v->k = VEXP;
+ v->info = 0; /* closed expression */
+ }
+ else /* variable name */
+ singlevar(ls, checkname(ls), v, 0);
+ var_or_func_tail(ls, v);
+}
+
+static void var_or_func_tail (LexState *ls, vardesc *v) {
+ for (;;) {
+ switch (ls->token) {
+ case '.': /* var_or_func_tail -> '.' NAME */
+ next(ls);
+ lua_pushvar(ls, v); /* 'v' must be on stack */
+ v->k = VDOT;
+ v->info = string_constant(ls->fs, checkname(ls));
+ break;
+
+ case '[': /* var_or_func_tail -> '[' exp1 ']' */
+ next(ls);
+ lua_pushvar(ls, v); /* 'v' must be on stack */
+ exp1(ls);
+ check(ls, ']');
+ v->k = VINDEXED;
+ break;
+
+ case ':': /* var_or_func_tail -> ':' NAME funcparams */
+ next(ls);
+ lua_pushvar(ls, v); /* 'v' must be on stack */
+ code_oparg(ls, PUSHSELF, 8, string_constant(ls->fs, checkname(ls)), 1);
+ v->k = VEXP;
+ v->info = funcparams(ls, 1);
+ break;
+
+ case '(': case STRING: case '{': /* var_or_func_tail -> funcparams */
+ lua_pushvar(ls, v); /* 'v' must be on stack */
+ v->k = VEXP;
+ v->info = funcparams(ls, 0);
+ break;
+
+ default: return; /* should be follow... */
+ }
+ }
+}
+
+static int funcparams (LexState *ls, int slf) {
+ FuncState *fs = ls->fs;
+ int nparams = 1; /* default value */
+ switch (ls->token) {
+ case '(': { /* funcparams -> '(' explist ')' */
+ listdesc e;
+ next(ls);
+ explist(ls, &e);
+ check(ls, ')');
+ close_exp(ls, e.pc, 1);
+ nparams = e.n;
+ break;
+ }
+
+ case '{': /* funcparams -> constructor */
+ constructor(ls);
+ break;
+
+ case STRING: /* funcparams -> STRING */
+ code_string(ls, ls->seminfo.ts);
+ next(ls);
+ break;
+
+ default:
+ luaX_error(ls, "function arguments expected");
+ break;
+ }
+ code_byte(fs, 0); /* save space for opcode */
+ code_byte(fs, 0); /* and nresult */
+ code_byte(fs, nparams+slf);
+ return fs->pc-1;
+}
+
+static void explist (LexState *ls, listdesc *d) {
+ switch (ls->token) {
+ case ELSE: case ELSEIF: case END: case UNTIL:
+ case EOS: case ';': case ')':
+ d->pc = 0;
+ d->n = 0;
+ break;
+
+ default:
+ explist1(ls, d);
+ }
+}
+
+static void explist1 (LexState *ls, listdesc *d) {
+ vardesc v;
+ exp0(ls, &v);
+ d->n = 1;
+ while (ls->token == ',') {
+ d->n++;
+ lua_pushvar(ls, &v);
+ next(ls);
+ exp0(ls, &v);
+ }
+ if (v.k == VEXP)
+ d->pc = v.info;
+ else {
+ lua_pushvar(ls, &v);
+ d->pc = 0;
+ }
+}
+
+static void parlist (LexState *ls) {
+ int nparams = 0;
+ int dots = 0;
+ switch (ls->token) {
+ case DOTS: /* parlist -> DOTS */
+ next(ls);
+ dots = 1;
+ break;
+
+ case NAME: /* parlist, tailparlist -> NAME [',' tailparlist] */
+ init:
+ store_localvar(ls, checkname(ls), nparams++);
+ if (ls->token == ',') {
+ next(ls);
+ switch (ls->token) {
+ case DOTS: /* tailparlist -> DOTS */
+ next(ls);
+ dots = 1;
+ break;
+
+ case NAME: /* tailparlist -> NAME [',' tailparlist] */
+ goto init;
+
+ default: luaX_error(ls, "NAME or `...' expected");
+ }
+ }
+ break;
+
+ case ')': break; /* parlist -> empty */
+
+ default: luaX_error(ls, "NAME or `...' expected");
+ }
+ code_args(ls, nparams, dots);
+}
+
+static int localnamelist (LexState *ls) {
+ /* localnamelist -> NAME {',' NAME} */
+ int i = 1;
+ store_localvar(ls, checkname(ls), 0);
+ while (ls->token == ',') {
+ next(ls);
+ store_localvar(ls, checkname(ls), i++);
+ }
+ return i;
+}
+
+static void decinit (LexState *ls, listdesc *d) {
+ /* decinit -> ['=' explist1] */
+ if (ls->token == '=') {
+ next(ls);
+ explist1(ls, d);
+ }
+ else {
+ d->n = 0;
+ d->pc = 0;
+ }
+}
+
+static int assignment (LexState *ls, vardesc *v, int nvars) {
+ int left = 0;
+ /* dotted variables <a.x> must be stored like regular indexed vars <a["x"]> */
+ if (v->k == VDOT) {
+ code_constant(ls, v->info);
+ v->k = VINDEXED;
+ }
+ if (ls->token == ',') { /* assignment -> ',' NAME assignment */
+ vardesc nv;
+ next(ls);
+ var_or_func(ls, &nv);
+ if (nv.k == VEXP)
+ luaX_error(ls, "syntax error");
+ left = assignment(ls, &nv, nvars+1);
+ }
+ else { /* assignment -> '=' explist1 */
+ listdesc d;
+ check(ls, '=');
+ explist1(ls, &d);
+ adjust_mult_assign(ls, nvars, &d);
+ }
+ if (v->k != VINDEXED || left+(nvars-1) == 0) {
+ /* global/local var or indexed var without values in between */
+ storevar(ls, v);
+ }
+ else { /* indexed var with values in between*/
+ code_oparg(ls, SETTABLE, 0, left+(nvars-1), -1);
+ left += 2; /* table/index are not popped, because they aren't on top */
+ }
+ return left;
+}
+
+static void constructor (LexState *ls) {
+ /* constructor -> '{' part [';' part] '}' */
+ int line = ls->linenumber;
+ int pc = SaveWord(ls);
+ int nelems;
+ constdesc cd;
+ deltastack(ls, 1);
+ check(ls, '{');
+ part(ls, &cd);
+ nelems = cd.n;
+ if (ls->token == ';') {
+ constdesc other_cd;
+ next(ls);
+ part(ls, &other_cd);
+ if (cd.k == other_cd.k) /* repeated parts? */
+ luaX_error(ls, "invalid constructor syntax");
+ nelems += other_cd.n;
+ }
+ check_match(ls, '}', '{', line);
+ fix_opcode(ls, pc, CREATEARRAY, 2, nelems);
+}
+
+static void part (LexState *ls, constdesc *cd) {
+ switch (ls->token) {
+ case ';': case '}': /* part -> empty */
+ cd->n = 0;
+ cd->k = ls->token;
+ return;
+
+ case NAME: {
+ vardesc v;
+ exp0(ls, &v);
+ if (ls->token == '=') {
+ switch (v.k) {
+ case VGLOBAL:
+ code_constant(ls, v.info);
+ break;
+ case VLOCAL:
+ code_string(ls, ls->fs->localvar[v.info]);
+ break;
+ default:
+ luaX_error(ls, "`=' unexpected");
+ }
+ next(ls);
+ exp1(ls);
+ cd->n = recfields(ls);
+ cd->k = 1; /* record */
+ }
+ else {
+ lua_pushvar(ls, &v);
+ cd->n = listfields(ls);
+ cd->k = 0; /* list */
+ }
+ break;
+ }
+
+ case '[': /* part -> recfield recfields */
+ recfield(ls);
+ cd->n = recfields(ls);
+ cd->k = 1; /* record */
+ break;
+
+ default: /* part -> exp1 listfields */
+ exp1(ls);
+ cd->n = listfields(ls);
+ cd->k = 0; /* list */
+ break;
+ }
+}
+
+static int recfields (LexState *ls) {
+ /* recfields -> { ',' recfield } [','] */
+ int n = 1; /* one has been read before */
+ while (ls->token == ',') {
+ next(ls);
+ if (ls->token == ';' || ls->token == '}')
+ break;
+ recfield(ls);
+ n++;
+ if (n%RFIELDS_PER_FLUSH == 0)
+ flush_record(ls, RFIELDS_PER_FLUSH);
+ }
+ flush_record(ls, n%RFIELDS_PER_FLUSH);
+ return n;
+}
+
+static int listfields (LexState *ls) {
+ /* listfields -> { ',' exp1 } [','] */
+ int n = 1; /* one has been read before */
+ while (ls->token == ',') {
+ next(ls);
+ if (ls->token == ';' || ls->token == '}')
+ break;
+ exp1(ls);
+ n++;
+ if (n%LFIELDS_PER_FLUSH == 0)
+ flush_list(ls, n/LFIELDS_PER_FLUSH - 1, LFIELDS_PER_FLUSH);
+ }
+ flush_list(ls, n/LFIELDS_PER_FLUSH, n%LFIELDS_PER_FLUSH);
+ return n;
+}
+
+static void recfield (LexState *ls) {
+ /* recfield -> (NAME | '['exp1']') = exp1 */
+ switch (ls->token) {
+ case NAME:
+ code_string(ls, checkname(ls));
+ break;
+
+ case '[':
+ next(ls);
+ exp1(ls);
+ check(ls, ']');
+ break;
+
+ default: luaX_error(ls, "NAME or `[' expected");
+ }
+ check(ls, '=');
+ exp1(ls);
+}
+