--------------------------------
function Is_Potentially_Unevaluated (N : Node_Id) return Boolean is
+ function Has_Null_Others_Choice (Aggr : Node_Id) return Boolean;
+ -- Aggr is an array aggregate with static bounds and an others clause;
+ -- return True if the others choice of the given array aggregate does
+ -- not cover any component (i.e. is null).
+
+ function Non_Static_Or_Null_Range (N : Node_Id) return Boolean;
+ -- Return True if the given range is nonstatic or null
+
+ ----------------------------
+ -- Has_Null_Others_Choice --
+ ----------------------------
+
+ function Has_Null_Others_Choice (Aggr : Node_Id) return Boolean is
+ Idx : constant Node_Id := First_Index (Etype (Aggr));
+ Hiv : constant Uint := Expr_Value (Type_High_Bound (Etype (Idx)));
+ Lov : constant Uint := Expr_Value (Type_Low_Bound (Etype (Idx)));
+
+ begin
+ declare
+ Intervals : constant Interval_Lists.Discrete_Interval_List :=
+ Interval_Lists.Aggregate_Intervals (Aggr);
+
+ begin
+ -- The others choice is null if, after normalization, we
+ -- have a single interval covering the whole aggregate.
+
+ return Intervals'Length = 1
+ and then
+ Intervals (Intervals'First).Low = Lov
+ and then
+ Intervals (Intervals'First).High = Hiv;
+ end;
+
+ -- If the aggregate is malformed (that is, indexes are not disjoint)
+ -- then no action is needed at this stage; the error will be reported
+ -- later by the frontend.
+
+ exception
+ when Interval_Lists.Intervals_Error =>
+ return False;
+ end Has_Null_Others_Choice;
+
+ ------------------------------
+ -- Non_Static_Or_Null_Range --
+ ------------------------------
+
+ function Non_Static_Or_Null_Range (N : Node_Id) return Boolean is
+ Low, High : Node_Id;
+
+ begin
+ Get_Index_Bounds (N, Low, High);
+
+ -- Check static bounds
+
+ if not Compile_Time_Known_Value (Low)
+ or else not Compile_Time_Known_Value (High)
+ then
+ return True;
+
+ -- Check null range
+
+ elsif Expr_Value (High) < Expr_Value (Low) then
+ return True;
+ end if;
+
+ return False;
+ end Non_Static_Or_Null_Range;
+
+ -- Local variables
+
Par : Node_Id;
Expr : Node_Id;
+ -- Start of processing for Is_Potentially_Unevaluated
+
begin
Expr := N;
Par := N;
N_Not_In,
N_Or_Else,
N_Quantified_Expression)
+ and then not (Nkind (Par) = N_Aggregate
+ and then Is_Array_Type (Etype (Par)))
loop
Expr := Par;
Par := Parent (Par);
elsif Nkind (Par) = N_Quantified_Expression then
return Expr = Condition (Par);
+ elsif Nkind (Par) = N_Aggregate
+ and then Is_Array_Type (Etype (Par))
+ and then Nkind (Expr) = N_Component_Association
+ then
+ declare
+ Choice : Node_Id;
+ In_Others_Choice : Boolean := False;
+
+ begin
+ -- The expression of an array_component_association is potentially
+ -- unevaluated if the associated choice is a subtype_indication or
+ -- range that defines a nonstatic or null range.
+
+ Choice := First (Choices (Expr));
+ while Present (Choice) loop
+ if Nkind (Choice) = N_Range
+ and then Non_Static_Or_Null_Range (Choice)
+ then
+ return True;
+
+ elsif Nkind (Choice) = N_Identifier
+ and then Present (Scalar_Range (Etype (Choice)))
+ and then
+ Non_Static_Or_Null_Range (Scalar_Range (Etype (Choice)))
+ then
+ return True;
+
+ elsif Nkind (Choice) = N_Others_Choice then
+ In_Others_Choice := True;
+ end if;
+
+ Next (Choice);
+ end loop;
+
+ -- It is also potentially unevaluated if the associated choice
+ -- is an others choice and the applicable index constraint is
+ -- nonstatic or null.
+
+ if In_Others_Choice then
+ if not Compile_Time_Known_Bounds (Etype (Par)) then
+ return True;
+ else
+ return Has_Null_Others_Choice (Par);
+ end if;
+ end if;
+ end;
+
+ return False;
+
else
return False;
end if;
package body Interval_Lists is
+ procedure Check_Consistency (Intervals : Discrete_Interval_List);
+ -- Check that list is sorted, lacks null intervals, and has gaps
+ -- between intervals.
+
function In_Interval
(Value : Uint; Interval : Discrete_Interval) return Boolean;
-- Does the given value lie within the given interval?
+ procedure Normalize_Interval_List
+ (List : in out Discrete_Interval_List; Last : out Nat);
+ -- Perform sorting and merging as required by Check_Consistency.
+
+ -------------------------
+ -- Aggregate_Intervals --
+ -------------------------
+
+ function Aggregate_Intervals (N : Node_Id) return Discrete_Interval_List
+ is
+ pragma Assert (Nkind (N) = N_Aggregate
+ and then Is_Array_Type (Etype (N)));
+
+ function Unmerged_Intervals_Count return Nat;
+ -- Count the number of intervals given in the aggregate N; the others
+ -- choice (if present) is not taken into account.
+
+ function Unmerged_Intervals_Count return Nat is
+ Count : Nat := 0;
+ Choice : Node_Id;
+ Comp : Node_Id;
+ begin
+ Comp := First (Component_Associations (N));
+ while Present (Comp) loop
+ Choice := First (Choices (Comp));
+
+ while Present (Choice) loop
+ if Nkind (Choice) /= N_Others_Choice then
+ Count := Count + 1;
+ end if;
+
+ Next (Choice);
+ end loop;
+
+ Next (Comp);
+ end loop;
+
+ return Count;
+ end Unmerged_Intervals_Count;
+
+ -- Local variables
+
+ Comp : Node_Id;
+ Max_I : constant Nat := Unmerged_Intervals_Count;
+ Intervals : Discrete_Interval_List (1 .. Max_I);
+ Num_I : Nat := 0;
+
+ begin
+ -- No action needed if there are no intervals
+
+ if Max_I = 0 then
+ return Intervals;
+ end if;
+
+ -- Internally store all the unsorted intervals
+
+ Comp := First (Component_Associations (N));
+ while Present (Comp) loop
+ declare
+ Choice_Intervals : constant Discrete_Interval_List
+ := Choice_List_Intervals (Choices (Comp));
+ begin
+ for J in Choice_Intervals'Range loop
+ Num_I := Num_I + 1;
+ Intervals (Num_I) := Choice_Intervals (J);
+ end loop;
+ end;
+
+ Next (Comp);
+ end loop;
+
+ -- Normalize the lists sorting and merging the intervals
+
+ declare
+ Aggr_Intervals : Discrete_Interval_List (1 .. Num_I)
+ := Intervals (1 .. Num_I);
+ begin
+ Normalize_Interval_List (Aggr_Intervals, Num_I);
+ Check_Consistency (Aggr_Intervals (1 .. Num_I));
+ return Aggr_Intervals (1 .. Num_I);
+ end;
+ end Aggregate_Intervals;
+
-----------------
-- In_Interval --
-----------------
return Value >= Interval.Low and then Value <= Interval.High;
end In_Interval;
- procedure Check_Consistency (Intervals : Discrete_Interval_List);
- -- Check that list is sorted, lacks null intervals, and has gaps
- -- between intervals.
-
------------------------
-- Check_Consistency --
------------------------
end if;
end Type_Intervals;
- procedure Normalize_Interval_List
- (List : in out Discrete_Interval_List; Last : out Nat);
- -- Perform sorting and merging as required by Check_Consistency.
-
-----------------------------
-- Normalize_Interval_List --
-----------------------------
List (Idx) := Null_Interval;
Null_Interval_Count := Null_Interval_Count + 1;
else
+ if List (Idx).Low <= List (Not_Null).High then
+ raise Intervals_Error;
+ end if;
+
pragma Assert (List (Idx).Low > List (Not_Null).High);
Not_Null := Idx;
end if;
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