Update lua plugin to 5.2.3

Prior to this patch the Lua plugin used version 5.1.4. This change
reduces the number of modifications in the Lua source using some new
defines and because the upstream source is now more flexible.

Unless otherwise stated, l*.[ch] files are taken unmodified from the
upstream lua-5.2.3.

fscanf.c:
file descriptors in rockbox are just ints, they are hidden behind a
void* now so liolib requires less modifications. fscanf is updated to
use void* too.

getc.c: this is a new file required for getc implementation in lauxlib.c

lauxlib.c: LoadF replaced FILE* with int, the rockbox file
descriptor int are cast to FILE* (actually void* due to typedef).
getc uses the PREFIX version. stdin is not used, as per 5.1.4.

lbaselib.c: now uses strspn in the number parsing. print uses DEBUGF now
rather than being commented out.

lbitlib.c: use the built-in version from 5.2.3 rather than Reuben
Thomas's external library. Backwards compatible and adds some new bit
operations.

ldo.c: the LUAI_THROW/TRY defines are now in the core lua code, so have
been removed from rockconf.h

liolib.c: here the implementation has changed to use the LStream from
the original source, and cast the FILE* pointers to int. This has
reduced the number of modifications from the upstream version.

llex.c: the only change from upstream is to remove the locale include.

lmathlib.c: updated from the 5.2.3 version and re-applied the changes
that were made vs 5.1.4 for random numbers and to remove unsupported
float functions.

loadlib.c: upstream version, with the 5.1.4 changes for missing
functions.

lobject.c: upstream version, with ctype.h added and sprintf changed to
snprintf.

loslib.c: upstream version with locale.h removed and 5.1.4 changes for
unsupportable functions.

lstrlib.c: sprintf changed to snprintf.

ltable.c: upstream with the hashnum function from 5.1.4 to avoid frexp
in luai_hashnum.

luaconf.h: updated to 5.2.3 version, restored relevant parts from the
original 5.1.4 configuration. The COMPAT defines that are no longer
available are not included.

lundump.c: VERSION macro conflicts with the core Rockbox equivalent.

rocklib.c: luaL_reg is no longer available, replaced by luaL_Reg
equivalent. Moved checkboolean/optboolean functions to this file and out
of core lua files. luaL_getn is no longer available, replaced by
luaL_rawlen. luaL_register is deprecated, use the newlib/setfuncs
replacements. rli_init has to be called before setting up the newlib to
avoid overwriting the rb table.

rocklib_aux.pl: use rli_checkboolean from rocklib.c.

rocklua.c: new default bits library used, update the library loading
code with idiomatic 5.2 code.

strcspn.c: no longer needed, but strspn.c is required for strspn in
lbaselib.c

Change-Id: I0c7945c755f79083afe98ec117e1e8cf13de2651
Reviewed-on: http://gerrit.rockbox.org/774
Tested: Richard Quirk <richard.quirk@gmail.com>
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>

1 files changed, 417 insertions, 254 deletions

diff --git a/apps/plugins/lua/ldo.c b/apps/plugins/lua/ldo.c
index f303c744c7..e9dd5fa951 100644
--- a/apps/plugins/lua/ldo.c
+++ b/apps/plugins/lua/ldo.c
@@ -1,11 +1,11 @@
 /*
-** $Id: ldo.c,v 2.38.1.3 2008/01/18 22:31:22 roberto Exp $
+** $Id: ldo.c,v 2.108.1.3 2013/11/08 18:22:50 roberto Exp $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
 
 
-/* #include <setjmp.h> */
+#include <setjmp.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -14,6 +14,7 @@
 
 #include "lua.h"
 
+#include "lapi.h"
 #include "ldebug.h"
 #include "ldo.h"
 #include "lfunc.h"
@@ -39,6 +40,38 @@
 ** =======================================================
 */
 
+/*
+** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By
+** default, Lua handles errors with exceptions when compiling as
+** C++ code, with _longjmp/_setjmp when asked to use them, and with
+** longjmp/setjmp otherwise.
+*/
+#if !defined(LUAI_THROW)
+
+#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP)
+/* C++ exceptions */
+#define LUAI_THROW(L,c)         throw(c)
+#define LUAI_TRY(L,c,a) \
+        try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; }
+#define luai_jmpbuf             int  /* dummy variable */
+
+#elif defined(LUA_USE_ULONGJMP)
+/* in Unix, try _longjmp/_setjmp (more efficient) */
+#define LUAI_THROW(L,c)         _longjmp((c)->b, 1)
+#define LUAI_TRY(L,c,a)         if (_setjmp((c)->b) == 0) { a }
+#define luai_jmpbuf             jmp_buf
+
+#else
+/* default handling with long jumps */
+#define LUAI_THROW(L,c)         longjmp((c)->b, 1)
+#define LUAI_TRY(L,c,a)         if (setjmp((c)->b) == 0) { a }
+#define luai_jmpbuf             jmp_buf
+
+#endif
+
+#endif
+
+
 
 /* chain list of long jump buffers */
 struct lua_longjmp {
@@ -48,18 +81,17 @@ struct lua_longjmp {
 };
 
 
-void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
   switch (errcode) {
-    case LUA_ERRMEM: {
-      setsvalue2s(L, oldtop, luaS_newliteral(L, MEMERRMSG));
+    case LUA_ERRMEM: {  /* memory error? */
+      setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
       break;
     }
     case LUA_ERRERR: {
       setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
       break;
     }
-    case LUA_ERRSYNTAX:
-    case LUA_ERRRUN: {
+    default: {
       setobjs2s(L, oldtop, L->top - 1);  /* error message on current top */
       break;
     }
@@ -68,55 +100,39 @@ void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
 }
 
 
-static void restore_stack_limit (lua_State *L) {
-  lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK - 1);
-  if (L->size_ci > LUAI_MAXCALLS) {  /* there was an overflow? */
-    int inuse = cast_int(L->ci - L->base_ci);
-    if (inuse + 1 < LUAI_MAXCALLS)  /* can `undo' overflow? */
-      luaD_reallocCI(L, LUAI_MAXCALLS);
+l_noret luaD_throw (lua_State *L, int errcode) {
+  if (L->errorJmp) {  /* thread has an error handler? */
+    L->errorJmp->status = errcode;  /* set status */
+    LUAI_THROW(L, L->errorJmp);  /* jump to it */
   }
-}
-
-
-static void resetstack (lua_State *L, int status) {
-  L->ci = L->base_ci;
-  L->base = L->ci->base;
-  luaF_close(L, L->base);  /* close eventual pending closures */
-  luaD_seterrorobj(L, status, L->base);
-  L->nCcalls = L->baseCcalls;
-  L->allowhook = 1;
-  restore_stack_limit(L);
-  L->errfunc = 0;
-  L->errorJmp = NULL;
-}
-
-
-void luaD_throw (lua_State *L, int errcode) {
-  if (L->errorJmp) {
-    L->errorJmp->status = errcode;
-    LUAI_THROW(L, L->errorJmp);
-  }
-  else {
-    L->status = cast_byte(errcode);
-    if (G(L)->panic) {
-      resetstack(L, errcode);
-      lua_unlock(L);
-      G(L)->panic(L);
+  else {  /* thread has no error handler */
+    L->status = cast_byte(errcode);  /* mark it as dead */
+    if (G(L)->mainthread->errorJmp) {  /* main thread has a handler? */
+      setobjs2s(L, G(L)->mainthread->top++, L->top - 1);  /* copy error obj. */
+      luaD_throw(G(L)->mainthread, errcode);  /* re-throw in main thread */
+    }
+    else {  /* no handler at all; abort */
+      if (G(L)->panic) {  /* panic function? */
+        lua_unlock(L);
+        G(L)->panic(L);  /* call it (last chance to jump out) */
+      }
+      abort();
     }
-    exit(EXIT_FAILURE);
   }
 }
 
 
 int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
+  unsigned short oldnCcalls = L->nCcalls;
   struct lua_longjmp lj;
-  lj.status = 0;
+  lj.status = LUA_OK;
   lj.previous = L->errorJmp;  /* chain new error handler */
   L->errorJmp = &lj;
   LUAI_TRY(L, &lj,
     (*f)(L, ud);
   );
   L->errorJmp = lj.previous;  /* restore old error handler */
+  L->nCcalls = oldnCcalls;
   return lj.status;
 }
 
@@ -129,112 +145,127 @@ static void correctstack (lua_State *L, TValue *oldstack) {
   L->top = (L->top - oldstack) + L->stack;
   for (up = L->openupval; up != NULL; up = up->gch.next)
     gco2uv(up)->v = (gco2uv(up)->v - oldstack) + L->stack;
-  for (ci = L->base_ci; ci <= L->ci; ci++) {
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {
     ci->top = (ci->top - oldstack) + L->stack;
-    ci->base = (ci->base - oldstack) + L->stack;
     ci->func = (ci->func - oldstack) + L->stack;
+    if (isLua(ci))
+      ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
   }
-  L->base = (L->base - oldstack) + L->stack;
 }
 
 
+/* some space for error handling */
+#define ERRORSTACKSIZE  (LUAI_MAXSTACK + 200)
+
+
 void luaD_reallocstack (lua_State *L, int newsize) {
   TValue *oldstack = L->stack;
-  int realsize = newsize + 1 + EXTRA_STACK;
-  lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK - 1);
-  luaM_reallocvector(L, L->stack, L->stacksize, realsize, TValue);
-  L->stacksize = realsize;
-  L->stack_last = L->stack+newsize;
+  int lim = L->stacksize;
+  lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
+  lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
+  luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue);
+  for (; lim < newsize; lim++)
+    setnilvalue(L->stack + lim); /* erase new segment */
+  L->stacksize = newsize;
+  L->stack_last = L->stack + newsize - EXTRA_STACK;
   correctstack(L, oldstack);
 }
 
 
-void luaD_reallocCI (lua_State *L, int newsize) {
-  CallInfo *oldci = L->base_ci;
-  luaM_reallocvector(L, L->base_ci, L->size_ci, newsize, CallInfo);
-  L->size_ci = newsize;
-  L->ci = (L->ci - oldci) + L->base_ci;
-  L->end_ci = L->base_ci + L->size_ci - 1;
+void luaD_growstack (lua_State *L, int n) {
+  int size = L->stacksize;
+  if (size > LUAI_MAXSTACK)  /* error after extra size? */
+    luaD_throw(L, LUA_ERRERR);
+  else {
+    int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK;
+    int newsize = 2 * size;
+    if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK;
+    if (newsize < needed) newsize = needed;
+    if (newsize > LUAI_MAXSTACK) {  /* stack overflow? */
+      luaD_reallocstack(L, ERRORSTACKSIZE);
+      luaG_runerror(L, "stack overflow");
+    }
+    else
+      luaD_reallocstack(L, newsize);
+  }
 }
 
 
-void luaD_growstack (lua_State *L, int n) {
-  if (n <= L->stacksize)  /* double size is enough? */
-    luaD_reallocstack(L, 2*L->stacksize);
-  else
-    luaD_reallocstack(L, L->stacksize + n);
+static int stackinuse (lua_State *L) {
+  CallInfo *ci;
+  StkId lim = L->top;
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {
+    lua_assert(ci->top <= L->stack_last);
+    if (lim < ci->top) lim = ci->top;
+  }
+  return cast_int(lim - L->stack) + 1;  /* part of stack in use */
 }
 
 
-static CallInfo *growCI (lua_State *L) {
-  if (L->size_ci > LUAI_MAXCALLS)  /* overflow while handling overflow? */
-    luaD_throw(L, LUA_ERRERR);
-  else {
-    luaD_reallocCI(L, 2*L->size_ci);
-    if (L->size_ci > LUAI_MAXCALLS)
-      luaG_runerror(L, "stack overflow");
-  }
-  return ++L->ci;
+void luaD_shrinkstack (lua_State *L) {
+  int inuse = stackinuse(L);
+  int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
+  if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK;
+  if (inuse > LUAI_MAXSTACK ||  /* handling stack overflow? */
+      goodsize >= L->stacksize)  /* would grow instead of shrink? */
+    condmovestack(L);  /* don't change stack (change only for debugging) */
+  else
+    luaD_reallocstack(L, goodsize);  /* shrink it */
 }
 
 
-void luaD_callhook (lua_State *L, int event, int line) {
+void luaD_hook (lua_State *L, int event, int line) {
   lua_Hook hook = L->hook;
   if (hook && L->allowhook) {
+    CallInfo *ci = L->ci;
     ptrdiff_t top = savestack(L, L->top);
-    ptrdiff_t ci_top = savestack(L, L->ci->top);
+    ptrdiff_t ci_top = savestack(L, ci->top);
     lua_Debug ar;
     ar.event = event;
     ar.currentline = line;
-    if (event == LUA_HOOKTAILRET)
-      ar.i_ci = 0;  /* tail call; no debug information about it */
-    else
-      ar.i_ci = cast_int(L->ci - L->base_ci);
+    ar.i_ci = ci;
     luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-    L->ci->top = L->top + LUA_MINSTACK;
-    lua_assert(L->ci->top <= L->stack_last);
+    ci->top = L->top + LUA_MINSTACK;
+    lua_assert(ci->top <= L->stack_last);
     L->allowhook = 0;  /* cannot call hooks inside a hook */
+    ci->callstatus |= CIST_HOOKED;
     lua_unlock(L);
     (*hook)(L, &ar);
     lua_lock(L);
     lua_assert(!L->allowhook);
     L->allowhook = 1;
-    L->ci->top = restorestack(L, ci_top);
+    ci->top = restorestack(L, ci_top);
     L->top = restorestack(L, top);
+    ci->callstatus &= ~CIST_HOOKED;
+  }
+}
+
+
+static void callhook (lua_State *L, CallInfo *ci) {
+  int hook = LUA_HOOKCALL;
+  ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
+  if (isLua(ci->previous) &&
+      GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
+    ci->callstatus |= CIST_TAIL;
+    hook = LUA_HOOKTAILCALL;
   }
+  luaD_hook(L, hook, -1);
+  ci->u.l.savedpc--;  /* correct 'pc' */
 }
 
 
 static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
   int i;
   int nfixargs = p->numparams;
-  Table *htab = NULL;
   StkId base, fixed;
-  for (; actual < nfixargs; ++actual)
-    setnilvalue(L->top++);
-#if defined(LUA_COMPAT_VARARG)
-  if (p->is_vararg & VARARG_NEEDSARG) { /* compat. with old-style vararg? */
-    int nvar = actual - nfixargs;  /* number of extra arguments */
-    lua_assert(p->is_vararg & VARARG_HASARG);
-    luaC_checkGC(L);
-    htab = luaH_new(L, nvar, 1);  /* create `arg' table */
-    for (i=0; i<nvar; i++)  /* put extra arguments into `arg' table */
-      setobj2n(L, luaH_setnum(L, htab, i+1), L->top - nvar + i);
-    /* store counter in field `n' */
-    setnvalue(luaH_setstr(L, htab, luaS_newliteral(L, "n")), cast_num(nvar));
-  }
-#endif
+  lua_assert(actual >= nfixargs);
   /* move fixed parameters to final position */
+  luaD_checkstack(L, p->maxstacksize);  /* check again for new 'base' */
   fixed = L->top - actual;  /* first fixed argument */
   base = L->top;  /* final position of first argument */
   for (i=0; i<nfixargs; i++) {
-    setobjs2s(L, L->top++, fixed+i);
-    setnilvalue(fixed+i);
-  }
-  /* add `arg' parameter */
-  if (htab) {
-    sethvalue(L, L->top++, htab);
-    lua_assert(iswhite(obj2gco(htab)));
+    setobjs2s(L, L->top++, fixed + i);
+    setnilvalue(fixed + i);
   }
   return base;
 }
@@ -256,100 +287,93 @@ static StkId tryfuncTM (lua_State *L, StkId func) {
 
 
 
-#define inc_ci(L) \
-  ((L->ci == L->end_ci) ? growCI(L) : \
-   (condhardstacktests(luaD_reallocCI(L, L->size_ci)), ++L->ci))
+#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
 
 
+/*
+** returns true if function has been executed (C function)
+*/
 int luaD_precall (lua_State *L, StkId func, int nresults) {
-  LClosure *cl;
-  ptrdiff_t funcr;
-  if (!ttisfunction(func)) /* `func' is not a function? */
-    func = tryfuncTM(L, func);  /* check the `function' tag method */
-  funcr = savestack(L, func);
-  cl = &clvalue(func)->l;
-  L->ci->savedpc = L->savedpc;
-  if (!cl->isC) {  /* Lua function? prepare its call */
-    CallInfo *ci;
-    StkId st, base;
-    Proto *p = cl->p;
-    luaD_checkstack(L, p->maxstacksize);
-    func = restorestack(L, funcr);
-    if (!p->is_vararg) {  /* no varargs? */
-      base = func + 1;
-      if (L->top > base + p->numparams)
-        L->top = base + p->numparams;
-    }
-    else {  /* vararg function */
-      int nargs = cast_int(L->top - func) - 1;
-      base = adjust_varargs(L, p, nargs);
-      func = restorestack(L, funcr);  /* previous call may change the stack */
+  lua_CFunction f;
+  CallInfo *ci;
+  int n;  /* number of arguments (Lua) or returns (C) */
+  ptrdiff_t funcr = savestack(L, func);
+  switch (ttype(func)) {
+    case LUA_TLCF:  /* light C function */
+      f = fvalue(func);
+      goto Cfunc;
+    case LUA_TCCL: {  /* C closure */
+      f = clCvalue(func)->f;
+     Cfunc:
+      luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = restorestack(L, funcr);
+      ci->top = L->top + LUA_MINSTACK;
+      lua_assert(ci->top <= L->stack_last);
+      ci->callstatus = 0;
+      luaC_checkGC(L);  /* stack grow uses memory */
+      if (L->hookmask & LUA_MASKCALL)
+        luaD_hook(L, LUA_HOOKCALL, -1);
+      lua_unlock(L);
+      n = (*f)(L);  /* do the actual call */
+      lua_lock(L);
+      api_checknelems(L, n);
+      luaD_poscall(L, L->top - n);
+      return 1;
     }
-    ci = inc_ci(L);  /* now `enter' new function */
-    ci->func = func;
-    L->base = ci->base = base;
-    ci->top = L->base + p->maxstacksize;
-    lua_assert(ci->top <= L->stack_last);
-    L->savedpc = p->code;  /* starting point */
-    ci->tailcalls = 0;
-    ci->nresults = nresults;
-    for (st = L->top; st < ci->top; st++)
-      setnilvalue(st);
-    L->top = ci->top;
-    if (L->hookmask & LUA_MASKCALL) {
-      L->savedpc++;  /* hooks assume 'pc' is already incremented */
-      luaD_callhook(L, LUA_HOOKCALL, -1);
-      L->savedpc--;  /* correct 'pc' */
+    case LUA_TLCL: {  /* Lua function: prepare its call */
+      StkId base;
+      Proto *p = clLvalue(func)->p;
+      n = cast_int(L->top - func) - 1;  /* number of real arguments */
+      luaD_checkstack(L, p->maxstacksize);
+      for (; n < p->numparams; n++)
+        setnilvalue(L->top++);  /* complete missing arguments */
+      if (!p->is_vararg) {
+        func = restorestack(L, funcr);
+        base = func + 1;
+      }
+      else {
+        base = adjust_varargs(L, p, n);
+        func = restorestack(L, funcr);  /* previous call can change stack */
+      }
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = func;
+      ci->u.l.base = base;
+      ci->top = base + p->maxstacksize;
+      lua_assert(ci->top <= L->stack_last);
+      ci->u.l.savedpc = p->code;  /* starting point */
+      ci->callstatus = CIST_LUA;
+      L->top = ci->top;
+      luaC_checkGC(L);  /* stack grow uses memory */
+      if (L->hookmask & LUA_MASKCALL)
+        callhook(L, ci);
+      return 0;
     }
-    return PCRLUA;
-  }
-  else {  /* if is a C function, call it */
-    CallInfo *ci;
-    int n;
-    luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-    ci = inc_ci(L);  /* now `enter' new function */
-    ci->func = restorestack(L, funcr);
-    L->base = ci->base = ci->func + 1;
-    ci->top = L->top + LUA_MINSTACK;
-    lua_assert(ci->top <= L->stack_last);
-    ci->nresults = nresults;
-    if (L->hookmask & LUA_MASKCALL)
-      luaD_callhook(L, LUA_HOOKCALL, -1);
-    lua_unlock(L);
-    n = (*curr_func(L)->c.f)(L);  /* do the actual call */
-    lua_lock(L);
-    if (n < 0)  /* yielding? */
-      return PCRYIELD;
-    else {
-      luaD_poscall(L, L->top - n);
-      return PCRC;
+    default: {  /* not a function */
+      func = tryfuncTM(L, func);  /* retry with 'function' tag method */
+      return luaD_precall(L, func, nresults);  /* now it must be a function */
     }
   }
 }
 
 
-static StkId callrethooks (lua_State *L, StkId firstResult) {
-  ptrdiff_t fr = savestack(L, firstResult);  /* next call may change stack */
-  luaD_callhook(L, LUA_HOOKRET, -1);
-  if (f_isLua(L->ci)) {  /* Lua function? */
-    while ((L->hookmask & LUA_MASKRET) && L->ci->tailcalls--) /* tail calls */
-      luaD_callhook(L, LUA_HOOKTAILRET, -1);
-  }
-  return restorestack(L, fr);
-}
-
-
 int luaD_poscall (lua_State *L, StkId firstResult) {
   StkId res;
   int wanted, i;
-  CallInfo *ci;
-  if (L->hookmask & LUA_MASKRET)
-    firstResult = callrethooks(L, firstResult);
-  ci = L->ci--;
+  CallInfo *ci = L->ci;
+  if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
+    if (L->hookmask & LUA_MASKRET) {
+      ptrdiff_t fr = savestack(L, firstResult);  /* hook may change stack */
+      luaD_hook(L, LUA_HOOKRET, -1);
+      firstResult = restorestack(L, fr);
+    }
+    L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
+  }
   res = ci->func;  /* res == final position of 1st result */
   wanted = ci->nresults;
-  L->base = (ci - 1)->base;  /* restore base */
-  L->savedpc = (ci - 1)->savedpc;  /* restore savedpc */
+  L->ci = ci = ci->previous;  /* back to caller */
   /* move results to correct place */
   for (i = wanted; i != 0 && firstResult < L->top; i--)
     setobjs2s(L, res++, firstResult++);
@@ -365,112 +389,226 @@ int luaD_poscall (lua_State *L, StkId firstResult) {
 ** The arguments are on the stack, right after the function.
 ** When returns, all the results are on the stack, starting at the original
 ** function position.
-*/ 
-void luaD_call (lua_State *L, StkId func, int nResults) {
+*/
+void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) {
   if (++L->nCcalls >= LUAI_MAXCCALLS) {
     if (L->nCcalls == LUAI_MAXCCALLS)
       luaG_runerror(L, "C stack overflow");
     else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
       luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
   }
-  if (luaD_precall(L, func, nResults) == PCRLUA)  /* is a Lua function? */
-    luaV_execute(L, 1);  /* call it */
+  if (!allowyield) L->nny++;
+  if (!luaD_precall(L, func, nResults))  /* is a Lua function? */
+    luaV_execute(L);  /* call it */
+  if (!allowyield) L->nny--;
   L->nCcalls--;
-  luaC_checkGC(L);
 }
 
 
-static void resume (lua_State *L, void *ud) {
-  StkId firstArg = cast(StkId, ud);
+static void finishCcall (lua_State *L) {
   CallInfo *ci = L->ci;
-  if (L->status == 0) {  /* start coroutine? */
-    lua_assert(ci == L->base_ci && firstArg > L->base);
-    if (luaD_precall(L, firstArg - 1, LUA_MULTRET) != PCRLUA)
-      return;
+  int n;
+  lua_assert(ci->u.c.k != NULL);  /* must have a continuation */
+  lua_assert(L->nny == 0);
+  if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
+    ci->callstatus &= ~CIST_YPCALL;  /* finish 'lua_pcall' */
+    L->errfunc = ci->u.c.old_errfunc;
   }
-  else {  /* resuming from previous yield */
-    lua_assert(L->status == LUA_YIELD);
-    L->status = 0;
-    if (!f_isLua(ci)) {  /* `common' yield? */
-      /* finish interrupted execution of `OP_CALL' */
-      lua_assert(GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_CALL ||
-                 GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_TAILCALL);
-      if (luaD_poscall(L, firstArg))  /* complete it... */
-        L->top = L->ci->top;  /* and correct top if not multiple results */
+  /* finish 'lua_callk'/'lua_pcall' */
+  adjustresults(L, ci->nresults);
+  /* call continuation function */
+  if (!(ci->callstatus & CIST_STAT))  /* no call status? */
+    ci->u.c.status = LUA_YIELD;  /* 'default' status */
+  lua_assert(ci->u.c.status != LUA_OK);
+  ci->callstatus = (ci->callstatus & ~(CIST_YPCALL | CIST_STAT)) | CIST_YIELDED;
+  lua_unlock(L);
+  n = (*ci->u.c.k)(L);
+  lua_lock(L);
+  api_checknelems(L, n);
+  /* finish 'luaD_precall' */
+  luaD_poscall(L, L->top - n);
+}
+
+
+static void unroll (lua_State *L, void *ud) {
+  UNUSED(ud);
+  for (;;) {
+    if (L->ci == &L->base_ci)  /* stack is empty? */
+      return;  /* coroutine finished normally */
+    if (!isLua(L->ci))  /* C function? */
+      finishCcall(L);
+    else {  /* Lua function */
+      luaV_finishOp(L);  /* finish interrupted instruction */
+      luaV_execute(L);  /* execute down to higher C 'boundary' */
     }
-    else  /* yielded inside a hook: just continue its execution */
-      L->base = L->ci->base;
   }
-  luaV_execute(L, cast_int(L->ci - L->base_ci));
 }
 
 
-static int resume_error (lua_State *L, const char *msg) {
-  L->top = L->ci->base;
-  setsvalue2s(L, L->top, luaS_new(L, msg));
-  incr_top(L);
-  lua_unlock(L);
-  return LUA_ERRRUN;
+/*
+** check whether thread has a suspended protected call
+*/
+static CallInfo *findpcall (lua_State *L) {
+  CallInfo *ci;
+  for (ci = L->ci; ci != NULL; ci = ci->previous) {  /* search for a pcall */
+    if (ci->callstatus & CIST_YPCALL)
+      return ci;
+  }
+  return NULL;  /* no pending pcall */
+}
+
+
+static int recover (lua_State *L, int status) {
+  StkId oldtop;
+  CallInfo *ci = findpcall(L);
+  if (ci == NULL) return 0;  /* no recovery point */
+  /* "finish" luaD_pcall */
+  oldtop = restorestack(L, ci->extra);
+  luaF_close(L, oldtop);
+  seterrorobj(L, status, oldtop);
+  L->ci = ci;
+  L->allowhook = ci->u.c.old_allowhook;
+  L->nny = 0;  /* should be zero to be yieldable */
+  luaD_shrinkstack(L);
+  L->errfunc = ci->u.c.old_errfunc;
+  ci->callstatus |= CIST_STAT;  /* call has error status */
+  ci->u.c.status = status;  /* (here it is) */
+  return 1;  /* continue running the coroutine */
+}
+
+
+/*
+** signal an error in the call to 'resume', not in the execution of the
+** coroutine itself. (Such errors should not be handled by any coroutine
+** error handler and should not kill the coroutine.)
+*/
+static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
+  L->top = firstArg;  /* remove args from the stack */
+  setsvalue2s(L, L->top, luaS_new(L, msg));  /* push error message */
+  api_incr_top(L);
+  luaD_throw(L, -1);  /* jump back to 'lua_resume' */
 }
 
 
-LUA_API int lua_resume (lua_State *L, int nargs) {
+/*
+** do the work for 'lua_resume' in protected mode
+*/
+static void resume (lua_State *L, void *ud) {
+  int nCcalls = L->nCcalls;
+  StkId firstArg = cast(StkId, ud);
+  CallInfo *ci = L->ci;
+  if (nCcalls >= LUAI_MAXCCALLS)
+    resume_error(L, "C stack overflow", firstArg);
+  if (L->status == LUA_OK) {  /* may be starting a coroutine */
+    if (ci != &L->base_ci)  /* not in base level? */
+      resume_error(L, "cannot resume non-suspended coroutine", firstArg);
+    /* coroutine is in base level; start running it */
+    if (!luaD_precall(L, firstArg - 1, LUA_MULTRET))  /* Lua function? */
+      luaV_execute(L);  /* call it */
+  }
+  else if (L->status != LUA_YIELD)
+    resume_error(L, "cannot resume dead coroutine", firstArg);
+  else {  /* resuming from previous yield */
+    L->status = LUA_OK;
+    ci->func = restorestack(L, ci->extra);
+    if (isLua(ci))  /* yielded inside a hook? */
+      luaV_execute(L);  /* just continue running Lua code */
+    else {  /* 'common' yield */
+      if (ci->u.c.k != NULL) {  /* does it have a continuation? */
+        int n;
+        ci->u.c.status = LUA_YIELD;  /* 'default' status */
+        ci->callstatus |= CIST_YIELDED;
+        lua_unlock(L);
+        n = (*ci->u.c.k)(L);  /* call continuation */
+        lua_lock(L);
+        api_checknelems(L, n);
+        firstArg = L->top - n;  /* yield results come from continuation */
+      }
+      luaD_poscall(L, firstArg);  /* finish 'luaD_precall' */
+    }
+    unroll(L, NULL);
+  }
+  lua_assert(nCcalls == L->nCcalls);
+}
+
+
+LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
   int status;
+  int oldnny = L->nny;  /* save 'nny' */
   lua_lock(L);
-  if (L->status != LUA_YIELD && (L->status != 0 || L->ci != L->base_ci))
-      return resume_error(L, "cannot resume non-suspended coroutine");
-  if (L->nCcalls >= LUAI_MAXCCALLS)
-    return resume_error(L, "C stack overflow");
   luai_userstateresume(L, nargs);
-  lua_assert(L->errfunc == 0);
-  L->baseCcalls = ++L->nCcalls;
+  L->nCcalls = (from) ? from->nCcalls + 1 : 1;
+  L->nny = 0;  /* allow yields */
+  api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
   status = luaD_rawrunprotected(L, resume, L->top - nargs);
-  if (status != 0) {  /* error? */
-    L->status = cast_byte(status);  /* mark thread as `dead' */
-    luaD_seterrorobj(L, status, L->top);
-    L->ci->top = L->top;
-  }
-  else {
-    lua_assert(L->nCcalls == L->baseCcalls);
-    status = L->status;
+  if (status == -1)  /* error calling 'lua_resume'? */
+    status = LUA_ERRRUN;
+  else {  /* yield or regular error */
+    while (status != LUA_OK && status != LUA_YIELD) {  /* error? */
+      if (recover(L, status))  /* recover point? */
+        status = luaD_rawrunprotected(L, unroll, NULL);  /* run continuation */
+      else {  /* unrecoverable error */
+        L->status = cast_byte(status);  /* mark thread as `dead' */
+        seterrorobj(L, status, L->top);
+        L->ci->top = L->top;
+        break;
+      }
+    }
+    lua_assert(status == L->status);
   }
-  --L->nCcalls;
+  L->nny = oldnny;  /* restore 'nny' */
+  L->nCcalls--;
+  lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
   lua_unlock(L);
   return status;
 }
 
 
-LUA_API int lua_yield (lua_State *L, int nresults) {
+LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) {
+  CallInfo *ci = L->ci;
   luai_userstateyield(L, nresults);
   lua_lock(L);
-  if (L->nCcalls > L->baseCcalls)
-    luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
-  L->base = L->top - nresults;  /* protect stack slots below */
+  api_checknelems(L, nresults);
+  if (L->nny > 0) {
+    if (L != G(L)->mainthread)
+      luaG_runerror(L, "attempt to yield across a C-call boundary");
+    else
+      luaG_runerror(L, "attempt to yield from outside a coroutine");
+  }
   L->status = LUA_YIELD;
+  ci->extra = savestack(L, ci->func);  /* save current 'func' */
+  if (isLua(ci)) {  /* inside a hook? */
+    api_check(L, k == NULL, "hooks cannot continue after yielding");
+  }
+  else {
+    if ((ci->u.c.k = k) != NULL)  /* is there a continuation? */
+      ci->u.c.ctx = ctx;  /* save context */
+    ci->func = L->top - nresults - 1;  /* protect stack below results */
+    luaD_throw(L, LUA_YIELD);
+  }
+  lua_assert(ci->callstatus & CIST_HOOKED);  /* must be inside a hook */
   lua_unlock(L);
-  return -1;
+  return 0;  /* return to 'luaD_hook' */
 }
 
 
 int luaD_pcall (lua_State *L, Pfunc func, void *u,
                 ptrdiff_t old_top, ptrdiff_t ef) {
   int status;
-  unsigned short oldnCcalls = L->nCcalls;
-  ptrdiff_t old_ci = saveci(L, L->ci);
+  CallInfo *old_ci = L->ci;
   lu_byte old_allowhooks = L->allowhook;
+  unsigned short old_nny = L->nny;
   ptrdiff_t old_errfunc = L->errfunc;
   L->errfunc = ef;
   status = luaD_rawrunprotected(L, func, u);
-  if (status != 0) {  /* an error occurred? */
+  if (status != LUA_OK) {  /* an error occurred? */
     StkId oldtop = restorestack(L, old_top);
-    luaF_close(L, oldtop);  /* close eventual pending closures */
-    luaD_seterrorobj(L, status, oldtop);
-    L->nCcalls = oldnCcalls;
-    L->ci = restoreci(L, old_ci);
-    L->base = L->ci->base;
-    L->savedpc = L->ci->savedpc;
+    luaF_close(L, oldtop);  /* close possible pending closures */
+    seterrorobj(L, status, oldtop);
+    L->ci = old_ci;
     L->allowhook = old_allowhooks;
-    restore_stack_limit(L);
+    L->nny = old_nny;
+    luaD_shrinkstack(L);
   }
   L->errfunc = old_errfunc;
   return status;
@@ -483,35 +621,60 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
 */
 struct SParser {  /* data to `f_parser' */
   ZIO *z;
-  Mbuffer buff;  /* buffer to be used by the scanner */
+  Mbuffer buff;  /* dynamic structure used by the scanner */
+  Dyndata dyd;  /* dynamic structures used by the parser */
+  const char *mode;
   const char *name;
 };
 
+
+static void checkmode (lua_State *L, const char *mode, const char *x) {
+  if (mode && strchr(mode, x[0]) == NULL) {
+    luaO_pushfstring(L,
+       "attempt to load a %s chunk (mode is " LUA_QS ")", x, mode);
+    luaD_throw(L, LUA_ERRSYNTAX);
+  }
+}
+
+
 static void f_parser (lua_State *L, void *ud) {
   int i;
-  Proto *tf;
   Closure *cl;
   struct SParser *p = cast(struct SParser *, ud);
-  int c = luaZ_lookahead(p->z);
-  luaC_checkGC(L);
-  tf = ((c == LUA_SIGNATURE[0]) ? luaU_undump : luaY_parser)(L, p->z,
-                                                             &p->buff, p->name);
-  cl = luaF_newLclosure(L, tf->nups, hvalue(gt(L)));
-  cl->l.p = tf;
-  for (i = 0; i < tf->nups; i++)  /* initialize eventual upvalues */
-    cl->l.upvals[i] = luaF_newupval(L);
-  setclvalue(L, L->top, cl);
-  incr_top(L);
+  int c = zgetc(p->z);  /* read first character */
+  if (c == LUA_SIGNATURE[0]) {
+    checkmode(L, p->mode, "binary");
+    cl = luaU_undump(L, p->z, &p->buff, p->name);
+  }
+  else {
+    checkmode(L, p->mode, "text");
+    cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
+  }
+  lua_assert(cl->l.nupvalues == cl->l.p->sizeupvalues);
+  for (i = 0; i < cl->l.nupvalues; i++) {  /* initialize upvalues */
+    UpVal *up = luaF_newupval(L);
+    cl->l.upvals[i] = up;
+    luaC_objbarrier(L, cl, up);
+  }
 }
 
 
-int luaD_protectedparser (lua_State *L, ZIO *z, const char *name) {
+int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
+                                        const char *mode) {
   struct SParser p;
   int status;
-  p.z = z; p.name = name;
+  L->nny++;  /* cannot yield during parsing */
+  p.z = z; p.name = name; p.mode = mode;
+  p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0;
+  p.dyd.gt.arr = NULL; p.dyd.gt.size = 0;
+  p.dyd.label.arr = NULL; p.dyd.label.size = 0;
   luaZ_initbuffer(L, &p.buff);
   status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc);
   luaZ_freebuffer(L, &p.buff);
+  luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size);
+  luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size);
+  luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size);
+  L->nny--;
   return status;
 }