When an inequality operator is used for a tagged type, the tree node for
the inequality prior to expansion (such as with -gnatc) reflects "/="
operator in Standard rather than being resolved to be a logical negation
of the tagged type's equality function. This is a problem for ASIS in
Corresponding_Equality_Operator. We now ensure that the rewriting of
a tagged inequality happens during analysis rather than being deferred
to expansion.
No simple test available.
Tested on x86_64-pc-linux-gnu, committed on trunk
2012-10-01 Gary Dismukes <dismu...@adacore.com>
* sem_ch4.adb (Find_Equality_Types.Try_One_Interp): Exclude the
predefined interpretation from consideration if it's for a "/="
operator of a tagged type. This will allow Analyze_Equality_Op to
rewrite the "/=" as a logical negation of a call to the appropriate
dispatching equality function. This needs to be done during
analysis rather than expansion for the benefit of ASIS, which
otherwise gets the unresolved N_Op_Ne operator from Standard.
Index: sem_ch4.adb
===================================================================
--- sem_ch4.adb (revision 191890)
+++ sem_ch4.adb (working copy)
@@ -5612,8 +5612,24 @@
return;
end if;
+ -- If the right operand has a type compatible with T1, check for an
+ -- acceptable interpretation, unless T1 is limited (no predefined
+ -- equality available), or this is use of a "/=" for a tagged type.
+ -- In the latter case, possible interpretations of equality need to
+ -- be considered, we don't want the default inequality declared in
+ -- Standard to be chosen, and the "/=" will be rewritten as a
+ -- negation of "=" (see the end of Analyze_Equality_Op). This ensures
+ -- that that rewriting happens during analysis rather than being
+ -- delayed until expansion (this is needed for ASIS, which only sees
+ -- the unexpanded tree). Note that if the node is N_Op_Ne, but Op_Id
+ -- is Name_Op_Eq then we still proceed with the interpretation,
+ -- because that indicates the potential rewriting case where the
+ -- interpretation to consider is actually "=" and the node may be
+ -- about to be rewritten by Analyze_Equality_Op.
+
if T1 /= Standard_Void_Type
and then Has_Compatible_Type (R, T1)
+
and then
((not Is_Limited_Type (T1)
and then not Is_Limited_Composite (T1))
@@ -5622,6 +5638,11 @@
(Is_Array_Type (T1)
and then not Is_Limited_Type (Component_Type (T1))
and then Available_Full_View_Of_Component (T1)))
+
+ and then
+ (Nkind (N) /= N_Op_Ne
+ or else not Is_Tagged_Type (T1)
+ or else Chars (Op_Id) = Name_Op_Eq)
then
if Found
and then Base_Type (T1) /= Base_Type (T_F)
