http://d.puremagic.com/issues/show_bug.cgi?id=271

           Summary: Incorrect constant evaluation of TypeInfo equality
                    comparisons
           Product: D
           Version: 0.163
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: wrong-code
          Severity: critical
          Priority: P1
         Component: DMD
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: daiphoenix@lycos.com


Consider:

  writefln( typeid(int) is typeid(int) );  // prints true (Correct)
  writefln( typeid(int) !is typeid(int) ); // prints false (Correct)

  writefln( typeid(int) == typeid(Object) ); // prints 0      (Correct)
  writefln( typeid(int) != typeid(Object) ); // prints false! (Correct)

  // prints true (INCORRECT), should be 1, an int:
  writefln( typeid(int) == typeid(int) );
  // prints true (INCORRECT), should be false:
  writefln( typeid(int) != typeid(int) );

  // prints bool (INCORRECT), should be int
  writefln( typeid(typeof(typeid(int) == typeid(int))) );

The bug is in the constant folding(evaluation) system: if we the check the asm for that code then 1(true) is generated for both == and != calls. Also, the following code, which are all runtime evaluations, work correctly:

  auto ti = typeid(int);
  writefln( ti == ti );          // prints 1     (Correct)
  writefln( ti != ti );          // prints false (Correct)
  writefln( ti == typeid(int) ); // prints 1     (Correct)
  writefln( ti != typeid(int) ); // prints false (Correct)


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=271


bugzilla@digitalmars.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED




------- Comment #1 from bugzilla@digitalmars.com  2006-08-11 19:19 -------
Fixed DMD 0.164


-- 

d-bugmail@puremagic.com schrieb am 2006-07-29:
> http://d.puremagic.com/issues/show_bug.cgi?id=271

> Consider:
>
>   writefln( typeid(int) is typeid(int) );  // prints true (Correct)
>   writefln( typeid(int) !is typeid(int) ); // prints false (Correct)
>
>   writefln( typeid(int) == typeid(Object) ); // prints 0      (Correct)
>   writefln( typeid(int) != typeid(Object) ); // prints false! (Correct)
>
>   // prints true (INCORRECT), should be 1, an int:
>   writefln( typeid(int) == typeid(int) );
>   // prints true (INCORRECT), should be false:
>   writefln( typeid(int) != typeid(int) );
>
>   // prints bool (INCORRECT), should be int
>   writefln( typeid(typeof(typeid(int) == typeid(int))) );
>
> The bug is in the constant folding(evaluation) system: if we the check the asm for that code then 1(true) is generated for both == and != calls. Also, the following code, which are all runtime evaluations, work correctly:
>
>   auto ti = typeid(int);
>   writefln( ti == ti );          // prints 1     (Correct)
>   writefln( ti != ti );          // prints false (Correct)
>   writefln( ti == typeid(int) ); // prints 1     (Correct)
>   writefln( ti != typeid(int) ); // prints false (Correct)

http://dstress.kuehne.cn/run/t/typeid_90_A.d http://dstress.kuehne.cn/run/t/typeid_90_B.d http://dstress.kuehne.cn/run/t/typeid_90_C.d http://dstress.kuehne.cn/run/t/typeid_90_D.d http://dstress.kuehne.cn/run/t/typeid_90_E.d http://dstress.kuehne.cn/run/t/typeid_90_F.d http://dstress.kuehne.cn/run/t/typeid_90_G.d http://dstress.kuehne.cn/run/t/typeid_90_H.d http://dstress.kuehne.cn/run/t/typeid_90_I.d http://dstress.kuehne.cn/run/t/typeid_90_J.d http://dstress.kuehne.cn/run/t/typeid_90_K.d

Thomas

Thomas Kuehne wrote:
> http://dstress.kuehne.cn/run/t/typeid_90_G.d

I don't think this test case is correct. You test the type-of a TypeInfo (which is an Object) equality operation vs the type-of an int(which is a primitive type) equality operation. Nothing says that such type-of should be the same (even though I very much think it should).

What I do think is not correct is the following (second line) :

writefln( typeid(typeof(typeid(int) == typeid(char))) );// int
writefln( typeid(typeof(typeid(int) == typeid(int))) );//bool INCORRECT?
writefln( typeid(typeof(new Object == new Object)) ); // int

writefln( typeid(typeof(typeid(int) != typeid(char))) ); // bool
writefln( typeid(typeof(typeid(int) != typeid(int))) );  // bool
writefln( typeid(typeof(new Object != new Object)) ); // bool

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D

Bruno Medeiros schrieb am 2006-08-14:
> Thomas Kuehne wrote:
>> http://dstress.kuehne.cn/run/t/typeid_90_G.d

for reference the test was:
#
# assert(typeid(typeof(typeid(int) == typeid(int))).toString()
#   == typeid(typeof(args[0].length == args.length)).toString());
#

> I don't think this test case is correct. You test the type-of a TypeInfo (which is an Object) equality operation vs the type-of an int(which is a primitive type) equality operation. Nothing says that such type-of should be the same (even though I very much think it should).
>
> What I do think is not correct is the following (second line) :
>
> writefln( typeid(typeof(typeid(int) == typeid(char))) );// int
> writefln( typeid(typeof(typeid(int) == typeid(int))) );//bool INCORRECT?
> writefln( typeid(typeof(new Object == new Object)) ); // int
>
> writefln( typeid(typeof(typeid(int) != typeid(char))) ); // bool
> writefln( typeid(typeof(typeid(int) != typeid(int))) );  // bool
> writefln( typeid(typeof(new Object != new Object)) ); // bool

See new issue tracker: http://d.puremagic.com/issues/show_bug.cgi?id=288

Thomas