PR# 16974 Classes with generic constraints crash compiler in {AST_TYPE_A_GENERATOR}.process_formal_as

Problem Report Summary

Submitter: prestoat2000

Category: Compiler

Priority: Medium

Date: 2010/07/20

Class: Bug

Severity: Serious

Number: 16974

Release: 6.7.83946

Confidential: No

Status: Closed

Responsible:

Environment: Mozilla/5.0 (X11; U; SunOS i86pc; en-US; rv:1.9.1.8) Gecko/20100226 Firefox/3.5.8 OpenSolaris snv_134 on x86

Synopsis: Classes with generic constraints crash compiler in {AST_TYPE_A_GENERATOR}.process_formal_as

Description

A set of classes which appear to be valid and that has a generic
constraint that references a generic class with a generic constraint
linked to another formal crashes the compiler in
{AST_TYPE_A_GENERATOR}.process_formal_as.

Added eweasel test term187 for this bug.

To Reproduce

Run eweasel test term187.

Problem Report Interactions

From:alexk_es Date:2011/09/28 Status: Closed Download

Fixed in rev#87352 of EiffelStudio 7.0 intermediate release.

From:prestoat2000 Date:2010/08/25 Download

I ran the associated test (term187) with a workbench compiler with
assertions enabled (rev 84288).  I got a compiler crash with:

-------------------------------------------------------------------------------
FORMAL_GENERIC_LIST_AS
                    i_th @2                valid_index:
<0000000012ADCC40>  (From ARRAYED_LIST)    Precondition violated.        Fail
-------------------------------------------------------------------------------

The compiler is trying to look at the 2nd element of the list but there
is only one element.  It appears to be checking the generic constraint
for class TEST1 which is 

   G -> TEST2 [TEST3 [INTEGER], INTEGER]

Note that TEST1 has only one formal generic, whereas TEST2 has 2 formals.
I think the compiler is getting confused and looking at the wrong class
or looking at the list of actual generics for the wrong class.