src/fallback.c

   1 /*
   2 ** fallback.c
   3 ** TecCGraf - PUC-Rio
   4 */
   5
   6 char *rcs_fallback="$Id: fallback.c,v 1.11 1995/02/06 19:34:03 roberto Exp $";
   7
   8 #include <stdio.h>
   9 #include <string.h>
  10
  11 #include "mem.h"
  12 #include "fallback.h"
  13 #include "opcode.h"
  14 #include "inout.h"
  15 #include "lua.h"
  16
  17
  18 static void errorFB (void);
  19 static void indexFB (void);
  20 static void gettableFB (void);
  21 static void arithFB (void);
  22 static void concatFB (void);
  23 static void orderFB (void);
  24 static void GDFB (void);
  25 static void funcFB (void);
  26
  27
  28 /*
  29 ** Warning: This list must be in the same order as the #define's
  30 */
  31 struct FB  luaI_fallBacks[] = {
  32 {"error", {LUA_T_CFUNCTION, errorFB}},
  33 {"index", {LUA_T_CFUNCTION, indexFB}},
  34 {"gettable", {LUA_T_CFUNCTION, gettableFB}},
  35 {"arith", {LUA_T_CFUNCTION, arithFB}},
  36 {"order", {LUA_T_CFUNCTION, orderFB}},
  37 {"concat", {LUA_T_CFUNCTION, concatFB}},
  38 {"settable", {LUA_T_CFUNCTION, gettableFB}},
  39 {"gc", {LUA_T_CFUNCTION, GDFB}},
  40 {"function", {LUA_T_CFUNCTION, funcFB}}
  41 };
  42
  43 #define N_FB  (sizeof(luaI_fallBacks)/sizeof(struct FB))
  44
  45 void luaI_setfallback (void)
  46 {
  47   int i;
  48   char *name = lua_getstring(lua_getparam(1));
  49   lua_Object func = lua_getparam(2);
  50   if (name == NULL || !(lua_isfunction(func) || lua_iscfunction(func)))
  51   {
  52     lua_pushnil();
  53     return;
  54   }
  55   for (i=0; i<N_FB; i++)
  56   {
  57     if (strcmp(luaI_fallBacks[i].kind, name) == 0)
  58     {
  59       luaI_pushobject(&luaI_fallBacks[i].function);
  60       luaI_fallBacks[i].function = *luaI_Address(func);
  61       return;
  62     }
  63   }
  64   /* name not found */
  65   lua_pushnil();
  66 }
  67
  68
  69 static void errorFB (void)
  70 {
  71   lua_Object o = lua_getparam(1);
  72   if (lua_isstring(o))
  73     fprintf (stderr, "lua: %s\n", lua_getstring(o));
  74   else
  75     fprintf(stderr, "lua: unknown error\n");
  76 }
  77
  78
  79 static void indexFB (void)
  80 {
  81   lua_pushnil();
  82 }
  83
  84
  85 static void gettableFB (void)
  86 {
  87   lua_reportbug("indexed expression not a table");
  88 }
  89
  90
  91 static void arithFB (void)
  92 {
  93   lua_reportbug("unexpected type at conversion to number");
  94 }
  95
  96 static void concatFB (void)
  97 {
  98   lua_reportbug("unexpected type at conversion to string");
  99 }
 100
 101
 102 static void orderFB (void)
 103 {
 104   lua_reportbug("unexpected type at comparison");
 105 }
 106
 107 static void GDFB (void) { }
 108
 109 static void funcFB (void)
 110 {
 111   lua_reportbug("call expression not a function");
 112 }
 113
 114
 115 /*
 116 ** Lock routines
 117 */
 118
 119 static Object *lockArray = NULL;
 120 static Word lockSize = 0;
 121
 122 int luaI_lock (Object *object)
 123 {
 124   Word i;
 125   Word oldSize;
 126   if (tag(object) == LUA_T_NIL)
 127     return -1;
 128   for (i=0; i<lockSize; i++)
 129     if (tag(&lockArray[i]) == LUA_T_NIL)
 130     {
 131       lockArray[i] = *object;
 132       return i;
 133     }
 134   /* no more empty spaces */
 135   oldSize = lockSize;
 136   if (lockArray == NULL)
 137   {
 138     lockSize = 10;
 139     lockArray = newvector(lockSize, Object);
 140   }
 141   else
 142   {
 143     lockSize = 3*oldSize/2 + 5;
 144     lockArray = growvector(lockArray, lockSize, Object);
 145   }
 146   for (i=oldSize; i<lockSize; i++)
 147     tag(&lockArray[i]) = LUA_T_NIL;
 148   lockArray[oldSize] = *object;
 149   return oldSize;
 150 }
 151
 152
 153 void lua_unlock (int ref)
 154 {
 155   tag(&lockArray[ref]) = LUA_T_NIL;
 156 }
 157
 158
 159 Object *luaI_getlocked (int ref)
 160 {
 161   return &lockArray[ref];
 162 }
 163
 164
 165 void luaI_travlock (void (*fn)(Object *))
 166 {
 167   Word i;
 168   for (i=0; i<lockSize; i++)
 169     fn(&lockArray[i]);
 170 }
 171