1 files changed, 171 insertions, 0 deletions
diff --git a/src/fallback.c b/src/fallback.c
new file mode 100644
index 00000000..d5bbbba1
--- /dev/null
+++ b/src/fallback.c
@@ -0,0 +1,171 @@
+/*
+** fallback.c
+** TecCGraf - PUC-Rio
+*/
+ 
+char *rcs_fallback="$Id: fallback.c,v 1.11 1995/02/06 19:34:03 roberto Exp $";
+
+#include <stdio.h>
+#include <string.h>
+ 
+#include "mem.h"
+#include "fallback.h"
+#include "opcode.h"
+#include "inout.h"
+#include "lua.h"
+
+
+static void errorFB (void);
+static void indexFB (void);
+static void gettableFB (void);
+static void arithFB (void);
+static void concatFB (void);
+static void orderFB (void);
+static void GDFB (void);
+static void funcFB (void);
+
+
+/*
+** Warning: This list must be in the same order as the #define's
+*/
+struct FB  luaI_fallBacks[] = {
+{"error", {LUA_T_CFUNCTION, errorFB}},
+{"index", {LUA_T_CFUNCTION, indexFB}},
+{"gettable", {LUA_T_CFUNCTION, gettableFB}},
+{"arith", {LUA_T_CFUNCTION, arithFB}},
+{"order", {LUA_T_CFUNCTION, orderFB}},
+{"concat", {LUA_T_CFUNCTION, concatFB}},
+{"settable", {LUA_T_CFUNCTION, gettableFB}},
+{"gc", {LUA_T_CFUNCTION, GDFB}},
+{"function", {LUA_T_CFUNCTION, funcFB}}
+};
+
+#define N_FB  (sizeof(luaI_fallBacks)/sizeof(struct FB))
+
+void luaI_setfallback (void)
+{
+  int i;
+  char *name = lua_getstring(lua_getparam(1));
+  lua_Object func = lua_getparam(2);
+  if (name == NULL || !(lua_isfunction(func) || lua_iscfunction(func)))
+  {
+    lua_pushnil();
+    return;
+  }
+  for (i=0; i<N_FB; i++)
+  {
+    if (strcmp(luaI_fallBacks[i].kind, name) == 0)
+    {
+      luaI_pushobject(&luaI_fallBacks[i].function);
+      luaI_fallBacks[i].function = *luaI_Address(func);
+      return;
+    }
+  }
+  /* name not found */
+  lua_pushnil();
+}
+
+
+static void errorFB (void)
+{
+  lua_Object o = lua_getparam(1);
+  if (lua_isstring(o))
+    fprintf (stderr, "lua: %s\n", lua_getstring(o));
+  else
+    fprintf(stderr, "lua: unknown error\n");
+}
+ 
+
+static void indexFB (void)
+{
+  lua_pushnil();
+}
+ 
+
+static void gettableFB (void)
+{
+  lua_reportbug("indexed expression not a table");
+}
+ 
+
+static void arithFB (void)
+{
+  lua_reportbug("unexpected type at conversion to number");
+}
+
+static void concatFB (void)
+{
+  lua_reportbug("unexpected type at conversion to string");
+}
+
+
+static void orderFB (void)
+{
+  lua_reportbug("unexpected type at comparison");
+}
+
+static void GDFB (void) { }
+
+static void funcFB (void)
+{
+  lua_reportbug("call expression not a function");
+}
+
+
+/*
+** Lock routines
+*/
+
+static Object *lockArray = NULL;
+static Word lockSize = 0;
+
+int luaI_lock (Object *object)
+{
+  Word i;
+  Word oldSize;
+  if (tag(object) == LUA_T_NIL)
+    return -1;
+  for (i=0; i<lockSize; i++)
+    if (tag(&lockArray[i]) == LUA_T_NIL)
+    {
+      lockArray[i] = *object;
+      return i;
+    }
+  /* no more empty spaces */
+  oldSize = lockSize;
+  if (lockArray == NULL)
+  {
+    lockSize = 10;
+    lockArray = newvector(lockSize, Object);
+  }
+  else
+  {
+    lockSize = 3*oldSize/2 + 5;
+    lockArray = growvector(lockArray, lockSize, Object);
+  }
+  for (i=oldSize; i<lockSize; i++)
+    tag(&lockArray[i]) = LUA_T_NIL;
+  lockArray[oldSize] = *object;
+  return oldSize;
+}
+
+
+void lua_unlock (int ref)
+{
+  tag(&lockArray[ref]) = LUA_T_NIL;
+}
+
+
+Object *luaI_getlocked (int ref)
+{
+  return &lockArray[ref];
+}
+
+
+void luaI_travlock (void (*fn)(Object *))
+{
+  Word i;
+  for (i=0; i<lockSize; i++)
+    fn(&lockArray[i]);
+}
+