1 files changed, 255 insertions, 0 deletions

diff --git a/src/lj_state.c b/src/lj_state.c
new file mode 100644
index 00000000..b4bc7a0c
--- /dev/null
+++ b/src/lj_state.c
@@ -0,0 +1,255 @@
+/*
+** State and stack handling.
+** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h
+**
+** Portions taken verbatim or adapted from the Lua interpreter.
+** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
+*/
+
+#define lj_state_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_str.h"
+#include "lj_tab.h"
+#include "lj_func.h"
+#include "lj_meta.h"
+#include "lj_state.h"
+#include "lj_frame.h"
+#include "lj_trace.h"
+#include "lj_dispatch.h"
+#include "lj_vm.h"
+#include "lj_lex.h"
+#include "lj_alloc.h"
+
+/* -- Stack handling ------------------------------------------------------ */
+
+/* Stack sizes. */
+#define LJ_STACK_MIN    LUA_MINSTACK    /* Min. stack size. */
+#define LJ_STACK_MAX    LUAI_MAXSTACK   /* Max. stack size. */
+#define LJ_STACK_START  (2*LJ_STACK_MIN)        /* Starting stack size. */
+#define LJ_STACK_MAXEX  (LJ_STACK_MAX + 1 + LJ_STACK_EXTRA)
+
+/* Explanation of LJ_STACK_EXTRA:
+**
+** Calls to metamethods store their arguments beyond the current top
+** without checking for the stack limit. This avoids stack resizes which
+** would invalidate passed TValue pointers. The stack check is performed
+** later by the call gate. This can safely resize the stack or raise an
+** error. Thus we need some extra slots beyond the current stack limit.
+**
+** Most metamethods need 4 slots above top (cont, mobj, arg1, arg2) plus
+** one extra slot if mobj is not a function. Only lj_meta_tset needs 5
+** slots above top, but then mobj is always a function. So we can get by
+** with 5 extra slots.
+*/
+
+/* Resize stack slots and adjust pointers in state. */
+static void resizestack(lua_State *L, MSize n)
+{
+  TValue *oldst = L->stack;
+  ptrdiff_t delta;
+  MSize realsize = n + 1 + LJ_STACK_EXTRA;
+  GCobj *up;
+  lua_assert((MSize)(L->maxstack-L->stack) == L->stacksize-LJ_STACK_EXTRA-1);
+  lj_mem_reallocvec(L, L->stack, L->stacksize, realsize, TValue);
+  delta = (char *)L->stack - (char *)oldst;
+  L->maxstack = L->stack + n;
+  L->stacksize = realsize;
+  L->base = (TValue *)((char *)L->base + delta);
+  L->top = (TValue *)((char *)L->top + delta);
+  for (up = gcref(L->openupval); up != NULL; up = gcnext(up))
+    gco2uv(up)->v = (TValue *)((char *)gco2uv(up)->v + delta);
+  if (obj2gco(L) == gcref(G(L)->jit_L))
+    setmref(G(L)->jit_base, mref(G(L)->jit_base, char) + delta);
+}
+
+/* Relimit stack after error, in case the limit was overdrawn. */
+void lj_state_relimitstack(lua_State *L)
+{
+  if (L->stacksize > LJ_STACK_MAXEX && L->top - L->stack < LJ_STACK_MAX-1)
+    resizestack(L, LJ_STACK_MAX);
+}
+
+/* Try to shrink the stack (called from GC). */
+void lj_state_shrinkstack(lua_State *L, MSize used)
+{
+  if (L->stacksize > LJ_STACK_MAXEX)
+    return;  /* Avoid stack shrinking while handling stack overflow. */
+  if (4*used < L->stacksize &&
+      2*(LJ_STACK_START+LJ_STACK_EXTRA) < L->stacksize &&
+      obj2gco(L) != gcref(G(L)->jit_L))  /* Don't shrink stack of live trace. */
+    resizestack(L, L->stacksize >> 1);
+}
+
+/* Try to grow stack. */
+void lj_state_growstack(lua_State *L, MSize need)
+{
+  if (L->stacksize > LJ_STACK_MAXEX)  /* overflow while handling overflow? */
+    lj_err_throw(L, LUA_ERRERR);
+  resizestack(L, L->stacksize + (need > L->stacksize ? need : L->stacksize));
+  if (L->stacksize > LJ_STACK_MAXEX) {
+    if (curr_funcisL(L)) {  /* Clear slots of incomplete Lua frame. */
+      TValue *top = curr_topL(L);
+      while (--top >= L->top) setnilV(top);
+    }
+    lj_err_msg(L, LJ_ERR_STKOV);  /* ... to allow L->top = curr_topL(L). */
+  }
+}
+
+void lj_state_growstack1(lua_State *L)
+{
+  lj_state_growstack(L, 1);
+}
+
+/* Allocate basic stack for new state. */
+static void stack_init(lua_State *L1, lua_State *L)
+{
+  L1->stack = lj_mem_newvec(L, LJ_STACK_START + LJ_STACK_EXTRA, TValue);
+  L1->stacksize = LJ_STACK_START + LJ_STACK_EXTRA;
+  L1->top = L1->stack;
+  L1->maxstack = L1->stack+(L1->stacksize - LJ_STACK_EXTRA)-1;
+  setthreadV(L1, L1->top, L1);  /* needed for curr_funcisL() on empty stack */
+  setnilV(L1->top);  /* but clear its type */
+  L1->base = ++L1->top;
+}
+
+/* -- State handling ------------------------------------------------------ */
+
+/* Open parts that may cause memory-allocation errors. */
+static TValue *cpluaopen(lua_State *L, lua_CFunction dummy, void *ud)
+{
+  global_State *g = G(L);
+  UNUSED(dummy);
+  UNUSED(ud);
+  stack_init(L, L);
+  /* NOBARRIER: State initialization, all objects are white. */
+  setgcref(L->env, obj2gco(lj_tab_new(L, 0, LJ_MIN_GLOBAL)));
+  settabV(L, registry(L), lj_tab_new(L, 0, LJ_MIN_REGISTRY));
+  lj_str_resize(L, LJ_MIN_STRTAB-1);
+  lj_meta_init(L);
+  lj_lex_init(L);
+  fixstring(lj_err_str(L, LJ_ERR_ERRMEM));  /* Preallocate memory error msg. */
+  g->gc.threshold = 4*g->gc.total;
+  return NULL;
+}
+
+static void close_state(lua_State *L)
+{
+  global_State *g = G(L);
+#ifndef LUAJIT_USE_SYSMALLOC
+  if (g->allocf == lj_alloc_f) {
+    lj_alloc_destroy(g->allocd);
+  } else
+#endif
+  {
+    lj_func_closeuv(L, L->stack);
+    lj_gc_freeall(g);
+    lua_assert(gcref(g->gc.root) == obj2gco(L));
+    lua_assert(g->strnum == 0);
+    lj_trace_freestate(g);
+    lj_mem_freevec(g, g->strhash, g->strmask+1, GCstr *);
+    lj_str_freebuf(g, &g->tmpbuf);
+    lj_mem_freevec(g, L->stack, L->stacksize, TValue);
+    lua_assert(g->gc.total == sizeof(GG_State));
+    g->allocf(g->allocd, G2GG(g), sizeof(GG_State), 0);
+  }
+}
+
+LUA_API lua_State *lua_newstate(lua_Alloc f, void *ud)
+{
+  GG_State *GG = cast(GG_State *, f(ud, NULL, 0, sizeof(GG_State)));
+  lua_State *L = &GG->L;
+  global_State *g = &GG->g;
+  if (GG == NULL) return NULL;
+  memset(GG, 0, sizeof(GG_State));
+  L->gct = ~LJ_TTHREAD;
+  L->marked = LJ_GC_WHITE0 | LJ_GC_FIXED | LJ_GC_SFIXED;  /* Prevent free. */
+  L->dummy_ffid = FF_C;
+  setmref(L->glref, g);
+  g->gc.currentwhite = LJ_GC_WHITE0 | LJ_GC_FIXED;
+  g->allocf = f;
+  g->allocd = ud;
+  setgcref(g->mainthref, obj2gco(L));
+  setgcref(g->uvhead.prev, obj2gco(&g->uvhead));
+  setgcref(g->uvhead.next, obj2gco(&g->uvhead));
+  g->strmask = ~(MSize)0;
+  setnilV(registry(L));
+  setnilV(&g->nilnode.val);
+  setnilV(&g->nilnode.key);
+  lj_str_initbuf(L, &g->tmpbuf);
+  g->gc.state = GCSpause;
+  setgcref(g->gc.root, obj2gco(L));
+  g->gc.sweep = &g->gc.root;
+  g->gc.total = sizeof(GG_State);
+  g->gc.pause = LUAI_GCPAUSE;
+  g->gc.stepmul = LUAI_GCMUL;
+  lj_dispatch_init((GG_State *)L);
+  L->status = LUA_ERRERR+1;  /* Avoid touching the stack upon memory error. */
+  if (lj_vm_cpcall(L, cpluaopen, NULL, NULL) != 0) {
+    /* Memory allocation error: free partial state. */
+    close_state(L);
+    return NULL;
+  }
+  L->status = 0;
+  return L;
+}
+
+static TValue *cpfinalize(lua_State *L, lua_CFunction dummy, void *ud)
+{
+  UNUSED(dummy);
+  UNUSED(ud);
+  lj_gc_finalizeudata(L);
+  /* Frame pop omitted. */
+  return NULL;
+}
+
+LUA_API void lua_close(lua_State *L)
+{
+  global_State *g = G(L);
+  L = mainthread(g);  /* Only the main thread can be closed. */
+  lj_func_closeuv(L, L->stack);
+  lj_gc_separateudata(g, 1);  /* Separate udata which have GC metamethods. */
+#if LJ_HASJIT
+  G2J(g)->flags &= ~JIT_F_ON;
+  G2J(g)->state = LJ_TRACE_IDLE;
+  lj_dispatch_update(g);
+#endif
+  do {
+    hook_enter(g);
+    L->status = 0;
+    L->cframe = NULL;
+    L->base = L->top = L->stack + 1;
+  } while (lj_vm_cpcall(L, cpfinalize, NULL, NULL) != 0);
+  close_state(L);
+}
+
+lua_State *lj_state_new(lua_State *L)
+{
+  lua_State *L1 = lj_mem_newobj(L, lua_State);
+  L1->gct = ~LJ_TTHREAD;
+  L1->dummy_ffid = FF_C;
+  L1->status = 0;
+  L1->stacksize = 0;
+  L1->stack = NULL;
+  L1->cframe = NULL;
+  /* NOBARRIER: The lua_State is new (marked white). */
+  setgcrefnull(L1->openupval);
+  setmrefr(L1->glref, L->glref);
+  setgcrefr(L1->env, L->env);
+  stack_init(L1, L);  /* init stack */
+  lua_assert(iswhite(obj2gco(L1)));
+  return L1;
+}
+
+void LJ_FASTCALL lj_state_free(global_State *g, lua_State *L)
+{
+  lua_assert(L != mainthread(g));
+  lj_func_closeuv(L, L->stack);
+  lua_assert(gcref(L->openupval) == NULL);
+  lj_mem_freevec(g, L->stack, L->stacksize, TValue);
+  lj_mem_freet(g, L);
+}
+