From: arne@vajhoej.dk   
      
   On 11/15/2025 10:04 AM, Dan Cross wrote:   
   > In article <10f30sp$1koun$4@dont-email.me>,   
   >> I consider the 3 biggest memory unsafe problems to be:   
   >> * no out of bounds check for array index   
   >> * allowing use of deallocated memory   
   >> * memory leak due to memory never being deallocated   
      
   >> Pascal only prevents the first not the other two.   
   >>   
   >> The other two are not as common in Pascal as in C,   
   >> because dynamic memory allocation is not as common in   
   >> Pascal as in C.   
   >   
   > Pascal is certainly an improvement over (at least) C and   
   > assembler languages in this domain: as I recall, it doesn't   
   > support arbitrary pointer arithmetic,   
      
   Standard: no.   
      
   VMS: only if jumping through hoops.   
      
   Delphi: easy peasy.   
      
   VMS code:   
      
   program pasptr(input,output);   
      
   type   
       char_arr = packed array [1..3] of char;   
       char_arr_ptr = ^char_arr;   
      
   var   
       p : char_arr_ptr;   
       hack1, hack3 : char_arr_ptr;   
       hack2, hack4 : [unsafe] char_arr_ptr;   
      
   begin   
       new(p);   
       p^ := 'ABC';   
       writeln(p^[1]);   
       hack1 := (p::integer + 1)::char_arr_ptr;   
       writeln(hack1^[1]);   
       hack2 := p::integer + 2;   
       writeln(hack2^[1]);   
       hack3 := (iaddress(p^) + 1)::char_arr_ptr;   
       writeln(hack3^[1]);   
       hack4 := iaddress(p^) + 2;   
       writeln(hack4^[1]);   
       dispose(p);   
   end.   
      
   That code is screaming for a code review.   
      
   Delphi code:   
      
   program pasptr(input, output);   
      
   var   
      p : pchar;   
      hack1, hack2 : pchar;   
      
   begin   
      GetMem(p, 3);   
      p := 'ABC';   
      writeln(p[0]);   
      hack1 := p + 1;   
      writeln(hack1[0]);   
      hack2 := @p[0] + 2;   
      writeln(hack2[0]);   
   end.   
      
   That code is C in Pascal.   
      
   >                                       and arrays are properly   
   > typed by including the array size in the type, and so on.   
   Either the dimension(s) is in the compile time declaration or   
   passed at runtime.   
      
   Arne   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)