[codegen] Optimize multiple constraints

[eclipse-ocl-bot]

| --- | --- | | Bugzilla Link | 401786 | | Status | NEW | | Importance | P3 enhancement | | Reported | Feb 26, 2013 08:31 EDT | | Modified | Jun 07, 2020 13:19 EDT | | Reporter | Ed Willink |

Description

Given constraints written as:

def checkSimpleConstraint() : Boolean = ...\ inv SimpleConstraint: checkSimpleConstraint()\ inv ComplexConstraint: checkSimpleConstraint() implies ...

the constraint evaluation should recognise that SimpleConstraint guard ComplexConstraint and avoid calling checkSimpleConstraint() twice.

[eclipse-ocl-bot]

By Ed Willink on Mar 15, 2013 07:10

It shouldn't be necessary for a user to refactor at all.

Constraints such as:\ inv A: ...\ inv B: ...\ inv C: ...

can be evaluated as (A and B and C) so that common sub-expression elimination hoists shared terms. It is only necessary to annotate the nested terms that correspond to explicit invariants to ensure that error reports reflect the user perspective.

[eclipse-ocl-bot]

By Ed Willink on Jun 07, 2020 13:11

This suggestion should also be searchable as a callable constraint / inavariant.

In Bug 544629#c8 The symbolic evaluator needs to pull in an invariant to provide some extra truth to avoid the symbolic validation failing.

An invariant may therefore be invoked as a true-valued-function in any function.

[eclipse-ocl-bot]

By Ed Willink on Jun 07, 2020 13:19

(In reply to Ed Willink from comment #2)

An invariant may therefore be invoked as a true-valued-function in any function.

But as a cached Boolean-valued prerequisite from any invariant.

CG/evaluation options could enable:

• evaluate function-called-invariants
• evaluate post-conditions
• evaluate post-conditions