An assignment to an entity E triggers an improper warning that an
immediately preceding assignment to E is useless, when the right-hand
side of the new assignment includes a target name, that is to say the
Ada2020 use of "@" to designate the left-hand side of the assignment.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_ch5.adb (Analyze_Assignment): Do not emit the warning that
a previous value of the target object is useless if the
right-hand side of the assignment includes target names.diff --git a/gcc/ada/sem_ch5.adb b/gcc/ada/sem_ch5.adb
--- a/gcc/ada/sem_ch5.adb
+++ b/gcc/ada/sem_ch5.adb
@@ -1108,6 +1108,12 @@ package body Sem_Ch5 is
-- warnings when an assignment is rewritten as another
-- assignment, and gets tied up with itself.
+ -- We also omit the warning if the RHS includes target names,
+ -- that is to say the Ada2020 "@" that denotes an instance of
+ -- the LHS, which indicates that the current value is being
+ -- used. Note that this implicit reference to the entity on
+ -- the RHS is not treated as a source reference.
+
-- There may have been a previous reference to a component of
-- the variable, which in general removes the Last_Assignment
-- field of the variable to indicate a relevant use of the
@@ -1126,6 +1132,7 @@ package body Sem_Ch5 is
and then Comes_From_Source (N)
and then In_Extended_Main_Source_Unit (Ent)
and then not Has_Deferred_Reference (Ent)
+ and then not Has_Target_Names (N)
then
Warn_On_Useless_Assignment (Ent, N);
end if;
