Re: range check test programs

29 Jul 2003

      On Sat, 12 Jul 2003, Frank Heckenbach wrote:

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Perhaps you've missed Francois' previous mail where he quoted the
items I have thought of already (appended below). If you can think
of more (which Francois didn't already write), fine, but first we
need someone to write those tests.
Sure.

Here is the point when I think I've done what I could. Let's go step by
step with this list (I'm sorry if I'm repepating something that has been
said already, but the list archive appears to be out :-(:
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What's missing is a test where the formal discriminants are of a
subrange type and the actual discriminants (in `New' or a variable
declaration) are out of range.
TEST    mir040a.pas:    gpc1: warnings being treated as errors
./mir040a.pas: In main program:
./mir040a.pas:34: warning: tag value must be a constant of ordinal type
failed   (I think it could be the problem in GPC, since the code is precisely
    the same, as with integer subrange bounds conformant arrays.)

Am I allowed to suppress this specific warning, is it possible
to do suppress it, or have I done something wrong?

(mir040a.pas is in attachment.)
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Initialization of types, variables and typed constants. (I.e.,
variables (or fields) or subrange type with an out-of-range
initializer; must be locally, otherwise GPC won't accept
non-constants initializers.)
Done. mir041[ceil][ul].pas
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The `FillChar' test (fsc20.pas) shouldn't (I think) work like this
since it takes an untyped parameter. (Some people (ab)use it for
strange purposes.) Instead, the 3rd parameter may also be an
integer, so it's an error if it's < 0 or > Ord (MaxChar).
Done: mir042[ul].pas
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I've found some more missing cases:
- `Return' (where the result type is a subrange and the `Return'
  value is out of range)
Done. mir0{24c[ul],25[ei][ul],26l[ul].pas
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- `Pack', `Unpack' (the index parameter)
Done. mir03[56]*.pas
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- `Include', `Exclude'
Done. mir028*.pas
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- `Inc', `Dec'
Done. mir027*.pas
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- 4th parameter of `BlockRead', `BlockWrite' (not obvious, but GPC
  allows a subrange here which may be too small for the actual
  result)
Done. mir039*.pas
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- `Val' (2nd and 3rd parameter)
Done 2nd parm. mir034[ab].pas

Q: What is the legal range for 3rd parm of Val?
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- `and', `or', `xor', `shl', `shr' used as procedures, e.g., if a is
  of type 1 .. 10: a := 5; or (a, 8) (whereas normal use as
  operators will be covered by assignments or whatever is done with
  them)
Done. mir03[0-3]*.pas
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- Conformant arrays (i.e., where the index type in the conformant
  array in the formal parameter list is a subrange, and the actual
  parameter's range is too big -- check both bounds)
Integer subrange Done. Problems with Char and enumerated subranges.
I can confirm that it gives me this error:

TEST    mir038ea.pas:   ./mir038ea.pas: In main program:
./mir038ea.pas:29: invalid operands to binary `+'
./mir038ea.pas:29: incompatible type for argument 1 of `conformantArray'
./mir038ea.pas:11:  routine declaration
failed

{$gnu-pascal}
program mir038ea;
{slice array write, what Francois has done for Integer here is for subrange}
uses GPC;
type TGrayScale = (Black, Gray10, Gray20, Gray30, Gray40, Gray50,
                   Gray60, Gray70, Gray80, Gray90, White);
     TMidTones = Gray30..Gray70;
var v   : array[1..100] of Integer;
    i,j : TGrayScale;
procedure  conformantArray(a: array[l..u : TMidTones] of Integer);
begin
end;

procedure ExpectError;
begin
  if ExitCode = 0 then
    WriteLn ('failed')
  else
    begin
      WriteLn ('OK');
      Halt (0) {!}
    end
end;

begin
   AtExit(ExpectError);
   i:=Gray30; j:=White;
   {j > upper}
   conformantArray(v[i..j]);
end.
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- `New' with variant records (where the variant tag is of subrange
  type)
See the generated warning in test above.
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- sets (e.g., assigning a set of a larger range to one of a smaller
  range where the former contains out of range elements)
Done. mir029*.pas

Conclusion:

1. variant record warning
2. Val's 3rd parameter
3. Possible bug with conformant arrays when bounds are of Char subrange,
   confirmed it occurs with enumerated subranges too
4. All tests WILL AND MUST give "failed" if you don't have range-checking
   compiler, with range-checking on, they should give OK

The latest result is at

    http://www.alu.hr/~mtodorov/pascal/rngv0.03.tar.gz

There is significantly more of them now than in v0.02, and some bugs are
fixed.

I think we're moving somewhere.

Have a nice day,
Mirsad

-- 
"I have a dream!" -- Martin Luther King Jr.

Mirsad Todorovac

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