* gdb.texinfo (Omissions from Ada): Document that there is now
limited aggregate support.
This commit is contained in:
parent
52ce64369c
commit
860701dc69
|
@ -1,3 +1,8 @@
|
|||
2006-01-02 Paul N. Hilfinger <hilfinger@gnat.com>
|
||||
|
||||
* gdb.texinfo (Omissions from Ada): Document that there is now
|
||||
limited aggregate support.
|
||||
|
||||
2005-12-28 Eli Zaretskii <eliz@gnu.org>
|
||||
|
||||
* gdb.texinfo (Registers): Describe how to refer to SSE and MMX
|
||||
|
|
|
@ -9812,7 +9812,52 @@ The other component-by-component array operations (@code{and}, @code{or},
|
|||
are not implemented.
|
||||
|
||||
@item
|
||||
There are no record or array aggregates.
|
||||
@cindex array aggregates (Ada)
|
||||
@cindex record aggregates (Ada)
|
||||
@cindex aggregates (Ada)
|
||||
There is limited support for array and record aggregates. They are
|
||||
permitted only on the right sides of assignments, as in these examples:
|
||||
|
||||
@smallexample
|
||||
set An_Array := (1, 2, 3, 4, 5, 6)
|
||||
set An_Array := (1, others => 0)
|
||||
set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6)
|
||||
set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9))
|
||||
set A_Record := (1, "Peter", True);
|
||||
set A_Record := (Name => "Peter", Id => 1, Alive => True)
|
||||
@end smallexample
|
||||
|
||||
Changing a
|
||||
discriminant's value by assigning an aggregate has an
|
||||
undefined effect if that discriminant is used within the record.
|
||||
However, you can first modify discriminants by directly assigning to
|
||||
them (which normally would not be allowed in Ada), and then performing an
|
||||
aggregate assignment. For example, given a variable @code{A_Rec}
|
||||
declared to have a type such as:
|
||||
|
||||
@smallexample
|
||||
type Rec (Len : Small_Integer := 0) is record
|
||||
Id : Integer;
|
||||
Vals : IntArray (1 .. Len);
|
||||
end record;
|
||||
@end smallexample
|
||||
|
||||
you can assign a value with a different size of @code{Vals} with two
|
||||
assignments:
|
||||
|
||||
@smallexample
|
||||
set A_Rec.Len := 4
|
||||
set A_Rec := (Id => 42, Vals => (1, 2, 3, 4))
|
||||
@end smallexample
|
||||
|
||||
As this example also illustrates, @value{GDBN} is very loose about the usual
|
||||
rules concerning aggregates. You may leave out some of the
|
||||
components of an array or record aggregate (such as the @code{Len}
|
||||
component in the assignment to @code{A_Rec} above); they will retain their
|
||||
original values upon assignment. You may freely use dynamic values as
|
||||
indices in component associations. You may even use overlapping or
|
||||
redundant component associations, although which component values are
|
||||
assigned in such cases is not defined.
|
||||
|
||||
@item
|
||||
Calls to dispatching subprograms are not implemented.
|
||||
|
|
Loading…
Reference in New Issue