[PATCH] PR fortran/46152 -- fix namespace pollution in type-spec matching

[Jerry DeLisle]

On 10/31/2010 07:37 AM, Steve Kargl wrote:
> On Sun, Oct 31, 2010 at 11:54:47AM +0100, Janus Weil wrote:
>>
>> What do you think about adding the following hunk in match.c to
>> improve the error message for this case:
>>
>>
>> @@ -2874,7 +2861,15 @@ gfc_match_allocate (void)
>>     if (m == MATCH_ERROR)
>>       goto cleanup;
>>     else if (m == MATCH_NO)
>> -    ts.type = BT_UNKNOWN;
>> +    {
>> +      char name[GFC_MAX_SYMBOL_LEN + 1];
>> +      if (gfc_match ("%n :: ", name) == MATCH_YES)
>> +       {
>> +         gfc_error ("Error in type-spec at %L",&old_locus);
>> +         goto cleanup;
>> +       }
>> +      ts.type = BT_UNKNOWN;
>> +    }
>>     else
>>       {
>>         if (gfc_match (" :: ") == MATCH_YES)
>>
>>
>> so that the test case becomes:
>>
>>
>> Index: gcc/testsuite/gfortran.dg/allocate_derived_1.f90
>> ===================================================================
>> --- gcc/testsuite/gfortran.dg/allocate_derived_1.f90    (revision 166088)
>> +++ gcc/testsuite/gfortran.dg/allocate_derived_1.f90    (working copy)
>> @@ -32,7 +32,7 @@
>>    allocate(t1 :: x(2))
>>    allocate(t2 :: x(3))
>>    allocate(t3 :: x(4))
>> - allocate(tx :: x(5))  ! { dg-error "is not an accessible derived type" }
>> + allocate(tx :: x(5))  ! { dg-error "Error in type-spec" }
>>    allocate(u0 :: x(6))  ! { dg-error "may not be ABSTRACT" }
>>    allocate(v1 :: x(7))  ! { dg-error "is type incompatible with typespec" }
>>
>>
>> I think this would be much better than complaining about something
>> being wrong with the allocate-object, since the colons indicate that
>> the (optional) type-spec is present, so we might as well make use of
>> this information.
>>
>> With this change the patch is ok from my side.
>>
>
> Thanks.  Your suggestion is exactly what was needed!
> I could not come up with what I considered a clean
> solution for
>
> module a
>     type rael
>       integer i
>     end type rael
>     type b
>       real x
>     end type b
> end module a
>
> program c
>     use a, only : b
>     real, allocatable :: x(:)
>     allocate(rael :: x(1))    ! inaccessible type or a typographical error?
> end program c
>

You are approved to commit now if regression testing passes.  No need to wait.

Jerry