src/func.c

   1 #include <string.h>
   2
   3 #include "luadebug.h"
   4 #include "table.h"
   5 #include "luamem.h"
   6 #include "func.h"
   7 #include "opcode.h"
   8 #include "inout.h"
   9
  10
  11 static TFunc *function_root = NULL;
  12 static LocVar *currvars = NULL;
  13 static int numcurrvars = 0;
  14 static int maxcurrvars = 0;
  15
  16
  17 /*
  18 ** Initialize TFunc struct
  19 */
  20 void luaI_initTFunc (TFunc *f)
  21 {
  22   f->next = NULL;
  23   f->marked = 0;
  24   f->size = 0;
  25   f->code = NULL;
  26   f->lineDefined = 0;
  27   f->fileName = lua_parsedfile;
  28   f->locvars = NULL;
  29 }
  30
  31 /*
  32 ** Insert function in list for GC
  33 */
  34 void luaI_insertfunction (TFunc *f)
  35 {
  36   lua_pack();
  37   f->next = function_root;
  38   function_root = f;
  39   f->marked = 0;
  40 }
  41
  42
  43 /*
  44 ** Free function
  45 */
  46 void luaI_freefunc (TFunc *f)
  47 {
  48   luaI_free (f->code);
  49   luaI_free (f->locvars);
  50   luaI_free (f);
  51 }
  52
  53
  54 void luaI_funcfree (TFunc *l)
  55 {
  56   while (l) {
  57     TFunc *next = l->next;
  58     luaI_freefunc(l);
  59     l = next;
  60   }
  61 }
  62
  63 /*
  64 ** Garbage collection function.
  65 */
  66 TFunc *luaI_funccollector (long *acum)
  67 {
  68   TFunc *curr = function_root;
  69   TFunc *prev = NULL;
  70   TFunc *frees = NULL;
  71   long counter = 0;
  72   while (curr) {
  73     TFunc *next = curr->next;
  74     if (!curr->marked) {
  75       if (prev == NULL)
  76         function_root = next;
  77       else
  78         prev->next = next;
  79       curr->next = frees;
  80       frees = curr;
  81       ++counter;
  82     }
  83     else {
  84       curr->marked = 0;
  85       prev = curr;
  86     }
  87     curr = next;
  88   }
  89   *acum += counter;
  90   return frees;
  91 }
  92
  93
  94 void lua_funcinfo (lua_Object func, char **filename, int *linedefined)
  95 {
  96   TObject *f = luaI_Address(func);
  97   if (f->ttype == LUA_T_MARK || f->ttype == LUA_T_FUNCTION)
  98   {
  99     *filename = f->value.tf->fileName;
 100     *linedefined = f->value.tf->lineDefined;
 101   }
 102   else if (f->ttype == LUA_T_CMARK || f->ttype == LUA_T_CFUNCTION)
 103   {
 104     *filename = "(C)";
 105     *linedefined = -1;
 106   }
 107 }
 108
 109 /*
 110 ** Stores information to know that variable has been declared in given line
 111 */
 112 void luaI_registerlocalvar (TaggedString *varname, int line)
 113 {
 114   if (numcurrvars >= maxcurrvars)
 115     maxcurrvars = growvector(&currvars, maxcurrvars, LocVar, "", MAX_WORD);
 116   currvars[numcurrvars].varname = varname;
 117   currvars[numcurrvars].line = line;
 118   numcurrvars++;
 119 }
 120
 121 /*
 122 ** Stores information to know that variable has been out of scope in given line
 123 */
 124 void luaI_unregisterlocalvar (int line)
 125 {
 126   luaI_registerlocalvar(NULL, line);
 127 }
 128
 129 /*
 130 ** Copies "currvars" into a new area and store it in function header.
 131 ** The values (varname = NULL, line = -1) signal the end of vector.
 132 */
 133 void luaI_closelocalvars (TFunc *func)
 134 {
 135   func->locvars = newvector (numcurrvars+1, LocVar);
 136   memcpy (func->locvars, currvars, numcurrvars*sizeof(LocVar));
 137   func->locvars[numcurrvars].varname = NULL;
 138   func->locvars[numcurrvars].line = -1;
 139   numcurrvars = 0;  /* prepares for next function */
 140 }
 141
 142 /*
 143 ** Look for n-esim local variable at line "line" in function "func".
 144 ** Returns NULL if not found.
 145 */
 146 char *luaI_getlocalname (TFunc *func, int local_number, int line)
 147 {
 148   int count = 0;
 149   char *varname = NULL;
 150   LocVar *lv = func->locvars;
 151   if (lv == NULL)
 152     return NULL;
 153   for (; lv->line != -1 && lv->line < line; lv++)
 154   {
 155     if (lv->varname)               /* register */
 156     {
 157       if (++count == local_number)
 158         varname = lv->varname->str;
 159     }
 160     else                           /* unregister */
 161       if (--count < local_number)
 162         varname = NULL;
 163   }
 164   return varname;
 165 }
 166