1 files changed, 299 insertions, 0 deletions

diff --git a/src/lua/lfunc.c b/src/lua/lfunc.c
new file mode 100644
index 0000000..10100e5
--- /dev/null
+++ b/src/lua/lfunc.c
@@ -0,0 +1,299 @@
+/*
+** $Id: lfunc.c $
+** Auxiliary functions to manipulate prototypes and closures
+** See Copyright Notice in lua.h
+*/
+
+#define lfunc_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <stddef.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+
+
+
+CClosure *luaF_newCclosure (lua_State *L, int nupvals) {
+  GCObject *o = luaC_newobj(L, LUA_VCCL, sizeCclosure(nupvals));
+  CClosure *c = gco2ccl(o);
+  c->nupvalues = cast_byte(nupvals);
+  return c;
+}
+
+
+LClosure *luaF_newLclosure (lua_State *L, int nupvals) {
+  GCObject *o = luaC_newobj(L, LUA_VLCL, sizeLclosure(nupvals));
+  LClosure *c = gco2lcl(o);
+  c->p = NULL;
+  c->nupvalues = cast_byte(nupvals);
+  while (nupvals--) c->upvals[nupvals] = NULL;
+  return c;
+}
+
+
+/*
+** fill a closure with new closed upvalues
+*/
+void luaF_initupvals (lua_State *L, LClosure *cl) {
+  int i;
+  for (i = 0; i < cl->nupvalues; i++) {
+    GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
+    UpVal *uv = gco2upv(o);
+    uv->v = &uv->u.value;  /* make it closed */
+    setnilvalue(uv->v);
+    cl->upvals[i] = uv;
+    luaC_objbarrier(L, cl, o);
+  }
+}
+
+
+/*
+** Create a new upvalue at the given level, and link it to the list of
+** open upvalues of 'L' after entry 'prev'.
+**/
+static UpVal *newupval (lua_State *L, int tbc, StkId level, UpVal **prev) {
+  GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
+  UpVal *uv = gco2upv(o);
+  UpVal *next = *prev;
+  uv->v = s2v(level);  /* current value lives in the stack */
+  uv->tbc = tbc;
+  uv->u.open.next = next;  /* link it to list of open upvalues */
+  uv->u.open.previous = prev;
+  if (next)
+    next->u.open.previous = &uv->u.open.next;
+  *prev = uv;
+  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
+    L->twups = G(L)->twups;  /* link it to the list */
+    G(L)->twups = L;
+  }
+  return uv;
+}
+
+
+/*
+** Find and reuse, or create if it does not exist, an upvalue
+** at the given level.
+*/
+UpVal *luaF_findupval (lua_State *L, StkId level) {
+  UpVal **pp = &L->openupval;
+  UpVal *p;
+  lua_assert(isintwups(L) || L->openupval == NULL);
+  while ((p = *pp) != NULL && uplevel(p) >= level) {  /* search for it */
+    lua_assert(!isdead(G(L), p));
+    if (uplevel(p) == level)  /* corresponding upvalue? */
+      return p;  /* return it */
+    pp = &p->u.open.next;
+  }
+  /* not found: create a new upvalue after 'pp' */
+  return newupval(L, 0, level, pp);
+}
+
+
+static void callclose (lua_State *L, void *ud) {
+  UNUSED(ud);
+  luaD_callnoyield(L, L->top - 3, 0);
+}
+
+
+/*
+** Prepare closing method plus its arguments for object 'obj' with
+** error message 'err'. (This function assumes EXTRA_STACK.)
+*/
+static int prepclosingmethod (lua_State *L, TValue *obj, TValue *err) {
+  StkId top = L->top;
+  const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
+  if (ttisnil(tm))  /* no metamethod? */
+    return 0;  /* nothing to call */
+  setobj2s(L, top, tm);  /* will call metamethod... */
+  setobj2s(L, top + 1, obj);  /* with 'self' as the 1st argument */
+  setobj2s(L, top + 2, err);  /* and error msg. as 2nd argument */
+  L->top = top + 3;  /* add function and arguments */
+  return 1;
+}
+
+
+/*
+** Raise an error with message 'msg', inserting the name of the
+** local variable at position 'level' in the stack.
+*/
+static void varerror (lua_State *L, StkId level, const char *msg) {
+  int idx = cast_int(level - L->ci->func);
+  const char *vname = luaG_findlocal(L, L->ci, idx, NULL);
+  if (vname == NULL) vname = "?";
+  luaG_runerror(L, msg, vname);
+}
+
+
+/*
+** Prepare and call a closing method. If status is OK, code is still
+** inside the original protected call, and so any error will be handled
+** there. Otherwise, a previous error already activated the original
+** protected call, and so the call to the closing method must be
+** protected here. (A status == CLOSEPROTECT behaves like a previous
+** error, to also run the closing method in protected mode).
+** If status is OK, the call to the closing method will be pushed
+** at the top of the stack. Otherwise, values are pushed after
+** the 'level' of the upvalue being closed, as everything after
+** that won't be used again.
+*/
+static int callclosemth (lua_State *L, StkId level, int status) {
+  TValue *uv = s2v(level);  /* value being closed */
+  if (likely(status == LUA_OK)) {
+    if (prepclosingmethod(L, uv, &G(L)->nilvalue))  /* something to call? */
+      callclose(L, NULL);  /* call closing method */
+    else if (!l_isfalse(uv))  /* non-closable non-false value? */
+      varerror(L, level, "attempt to close non-closable variable '%s'");
+  }
+  else {  /* must close the object in protected mode */
+    ptrdiff_t oldtop;
+    level++;  /* space for error message */
+    oldtop = savestack(L, level + 1);  /* top will be after that */
+    luaD_seterrorobj(L, status, level);  /* set error message */
+    if (prepclosingmethod(L, uv, s2v(level))) {  /* something to call? */
+      int newstatus = luaD_pcall(L, callclose, NULL, oldtop, 0);
+      if (newstatus != LUA_OK && status == CLOSEPROTECT)  /* first error? */
+        status = newstatus;  /* this will be the new error */
+      else {
+        if (newstatus != LUA_OK)  /* suppressed error? */
+          luaE_warnerror(L, "__close metamethod");
+        /* leave original error (or nil) on top */
+        L->top = restorestack(L, oldtop);
+      }
+    }
+    /* else no metamethod; ignore this case and keep original error */
+  }
+  return status;
+}
+
+
+/*
+** Try to create a to-be-closed upvalue
+** (can raise a memory-allocation error)
+*/
+static void trynewtbcupval (lua_State *L, void *ud) {
+  newupval(L, 1, cast(StkId, ud), &L->openupval);
+}
+
+
+/*
+** Create a to-be-closed upvalue. If there is a memory error
+** when creating the upvalue, the closing method must be called here,
+** as there is no upvalue to call it later.
+*/
+void luaF_newtbcupval (lua_State *L, StkId level) {
+  TValue *obj = s2v(level);
+  lua_assert(L->openupval == NULL || uplevel(L->openupval) < level);
+  if (!l_isfalse(obj)) {  /* false doesn't need to be closed */
+    int status;
+    const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
+    if (ttisnil(tm))  /* no metamethod? */
+      varerror(L, level, "variable '%s' got a non-closable value");
+    status = luaD_rawrunprotected(L, trynewtbcupval, level);
+    if (unlikely(status != LUA_OK)) {  /* memory error creating upvalue? */
+      lua_assert(status == LUA_ERRMEM);
+      luaD_seterrorobj(L, LUA_ERRMEM, level + 1);  /* save error message */
+      /* next call must succeed, as object is closable */
+      prepclosingmethod(L, s2v(level), s2v(level + 1));
+      callclose(L, NULL);  /* call closing method */
+      luaD_throw(L, LUA_ERRMEM);  /* throw memory error */
+    }
+  }
+}
+
+
+void luaF_unlinkupval (UpVal *uv) {
+  lua_assert(upisopen(uv));
+  *uv->u.open.previous = uv->u.open.next;
+  if (uv->u.open.next)
+    uv->u.open.next->u.open.previous = uv->u.open.previous;
+}
+
+
+int luaF_close (lua_State *L, StkId level, int status) {
+  UpVal *uv;
+  while ((uv = L->openupval) != NULL && uplevel(uv) >= level) {
+    TValue *slot = &uv->u.value;  /* new position for value */
+    lua_assert(uplevel(uv) < L->top);
+    if (uv->tbc && status != NOCLOSINGMETH) {
+      /* must run closing method, which may change the stack */
+      ptrdiff_t levelrel = savestack(L, level);
+      status = callclosemth(L, uplevel(uv), status);
+      level = restorestack(L, levelrel);
+    }
+    luaF_unlinkupval(uv);
+    setobj(L, slot, uv->v);  /* move value to upvalue slot */
+    uv->v = slot;  /* now current value lives here */
+    if (!iswhite(uv))
+      gray2black(uv);  /* closed upvalues cannot be gray */
+    luaC_barrier(L, uv, slot);
+  }
+  return status;
+}
+
+
+Proto *luaF_newproto (lua_State *L) {
+  GCObject *o = luaC_newobj(L, LUA_VPROTO, sizeof(Proto));
+  Proto *f = gco2p(o);
+  f->k = NULL;
+  f->sizek = 0;
+  f->p = NULL;
+  f->sizep = 0;
+  f->code = NULL;
+  f->sizecode = 0;
+  f->lineinfo = NULL;
+  f->sizelineinfo = 0;
+  f->abslineinfo = NULL;
+  f->sizeabslineinfo = 0;
+  f->upvalues = NULL;
+  f->sizeupvalues = 0;
+  f->numparams = 0;
+  f->is_vararg = 0;
+  f->maxstacksize = 0;
+  f->locvars = NULL;
+  f->sizelocvars = 0;
+  f->linedefined = 0;
+  f->lastlinedefined = 0;
+  f->source = NULL;
+  return f;
+}
+
+
+void luaF_freeproto (lua_State *L, Proto *f) {
+  luaM_freearray(L, f->code, f->sizecode);
+  luaM_freearray(L, f->p, f->sizep);
+  luaM_freearray(L, f->k, f->sizek);
+  luaM_freearray(L, f->lineinfo, f->sizelineinfo);
+  luaM_freearray(L, f->abslineinfo, f->sizeabslineinfo);
+  luaM_freearray(L, f->locvars, f->sizelocvars);
+  luaM_freearray(L, f->upvalues, f->sizeupvalues);
+  luaM_free(L, f);
+}
+
+
+/*
+** Look for n-th local variable at line 'line' in function 'func'.
+** Returns NULL if not found.
+*/
+const char *luaF_getlocalname (const Proto *f, int local_number, int pc) {
+  int i;
+  for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) {
+    if (pc < f->locvars[i].endpc) {  /* is variable active? */
+      local_number--;
+      if (local_number == 0)
+        return getstr(f->locvars[i].varname);
+    }
+  }
+  return NULL;  /* not found */
+}
+