libjava/testsuite/libjava.lang/newarray_overflow.java

   1 /* This test checks for two slightly different overflow scenarios in
   2  * array allocation.
   3  *
   4  * The first is that the number of bytes needed for an array size
   5  * overflows on a 32 bit machine.
   6  *
   7  * The second is that on a 64 machine, the number of bytes silently
   8  * gets truncated, resulting in too small an object being
   9  * allocated.  */
  10
  11 class newarray_overflow
  12 {
  13   static boolean failed = false;
  14
  15   static void int_check()
  16   {
  17     int[] x;
  18     try
  19       {
  20         x = new int [1 << 30];
  21       }
  22     catch (OutOfMemoryError e)
  23       {
  24         return;
  25       }
  26     /* If we really get away with it (64 bit machine), that's cool.  */
  27     if (x == null) {
  28       System.err.println ("int check: new returned null.");
  29       failed = true;
  30       return;
  31     }
  32     try
  33       {
  34         // Only check a few places so we don't thrash too badly.
  35         for (int i = 0; i < x.length; i += (1 << 24))
  36           if (x[i] != 0)
  37             failed = true;
  38       }
  39     catch (Throwable e)
  40       {
  41         System.err.print ("int check: ");
  42         System.err.println (e);
  43         failed = true;
  44       }
  45   }
  46
  47   static void object_check()
  48   {
  49     Object[] x;
  50     try
  51       {
  52         x = new Object [1 << 30];
  53         System.err.println ("Alloc succeeded.");
  54         System.err.println (x);
  55       }
  56     catch (OutOfMemoryError e)
  57       {
  58         return;
  59       }
  60     /* If we really get away with it (64 bit machine), that's cool.  */
  61     if (x == null) {
  62       System.err.println ("Object check: new returned null.");
  63       failed = true;
  64       return;
  65     }
  66     try
  67       {
  68         for (int i = 0; i < x.length; i += (1 << 24))
  69           if (x[i] != null)
  70             failed = true;
  71       }
  72     catch (Throwable e)
  73       {
  74         System.err.print ("Object check: ");
  75         System.err.println (e);
  76         failed = true;
  77       }
  78   }
  79
  80   public static void main (String[] ignore)
  81   {
  82     int_check();
  83     object_check();
  84
  85     if (!failed)
  86       System.out.println ("ok");
  87   }
  88 }