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[Ada] AI-0178 Incomplete views are limited

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

This AI clarifies the role of incomplete views and plugs an omission in the RM. GNAT always restricted correctly the use of incomplete views and types.

[Ada] AI-0007 Stream read and private scalar types

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The RM as written appeared to limit the possibilities of declaring read attribute procedures for private scalar types. This limitation was not intended, and has never been enforced by GNAT.

[Ada] AI-0008 General access to constrained objects

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The wording in the RM implied that if you have a general access to a constrained object, it could be used to modify the discriminants. This was obviously not intended. A constraint error should be raised, and GNAT has always raised a constraint error in this situation.

[Ada] AI-0015 Constant return objects

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The return object declared in an extended_return_statement may be declared constant. This was always intended, and GNAT has always allowed it.

[Ada] AI-0017 Freezing and incomplete types

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

Taft-amendment types are not frozen by the occurrence of bodies in the enclosing declarative part. GNAT always implemented this properly.

[Ada] AI-0019 Freezing of primitives for tagged types

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The RM suggests that primitive subprograms of a specific tagged type are frozen when the tagged type is frozen. This would be an incompatible change and is not intended. GNAT has never attempted this kind of freezing and its behavior is consistent with the recommendation of this AI.

[Ada] AI-0032 Extended return for class-wide functions

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

If a function returns a class-wide type, the object of an extended return statement can be declared with a specific type that is covered by the class- wide type. This has been implemented in GNAT since the introduction of extended returns. Note AI-0103 complements this one by imposing matching rules for constrained return types.

[Ada] AI-0002 Export C with unconstrained arrays

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The compiler is not required to support exporting an Ada subprogram with convention C if there are parameters or a return type of an unconstrained array type (such as String). GNAT allows such declarations but generates warnings. It is possible, but involved, to write the corresponding C code and certainly such code would be specific to GNAT and non-portable.

[Ada] AI-0034 Categorization of limited views

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

The RM makes certain limited with clauses illegal because of categorization considerations, when the corresponding normal with would be legal. This is not intended, and GNAT has always implemented the recommended behavior.

[Ada] AI-0037 Out-of-range box associations in aggregate

AdaCore — Fri, 27 Aug 2010 12:00:00 +0000

This AI confirms that an association of the form Indx => <> in an array aggregate must raise Constraint_Error if Indx is out of range. The RM specified a range check on other associations, but not when the value of the association was defaulted. GNAT always inserted a constraint check on the index value.