Refine predicate Must_Slide to ensure that no spurious range checks are
generated when context subtype and aggregate subtype are non-static.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_aggr.adb (Must_Slide): If the aggregate only contains an
others_clause no sliding id involved. Otherwise sliding is
required if any bound of the aggregate or the context subtype is
non-static.diff --git a/gcc/ada/exp_aggr.adb b/gcc/ada/exp_aggr.adb
--- a/gcc/ada/exp_aggr.adb
+++ b/gcc/ada/exp_aggr.adb
@@ -124,7 +124,8 @@ package body Exp_Aggr is
-- constants that are done in place.
function Must_Slide
- (Obj_Type : Entity_Id;
+ (Aggr : Node_Id;
+ Obj_Type : Entity_Id;
Typ : Entity_Id) return Boolean;
-- A static array aggregate in an object declaration can in most cases be
-- expanded in place. The one exception is when the aggregate is given
@@ -1776,7 +1777,7 @@ package body Exp_Aggr is
if Nkind (Parent (N)) = N_Assignment_Statement
and then Is_Array_Type (Comp_Typ)
and then Present (Component_Associations (Expr_Q))
- and then Must_Slide (Comp_Typ, Etype (Expr_Q))
+ and then Must_Slide (N, Comp_Typ, Etype (Expr_Q))
then
Set_Expansion_Delayed (Expr_Q, False);
Set_Analyzed (Expr_Q, False);
@@ -6855,7 +6856,7 @@ package body Exp_Aggr is
and then Parent_Kind = N_Object_Declaration
and then Present (Expression (Parent_Node))
and then not
- Must_Slide (Etype (Defining_Identifier (Parent_Node)), Typ)
+ Must_Slide (N, Etype (Defining_Identifier (Parent_Node)), Typ)
and then not Is_Bit_Packed_Array (Typ)
then
In_Place_Assign_OK_For_Declaration := True;
@@ -9616,13 +9617,16 @@ package body Exp_Aggr is
----------------
function Must_Slide
- (Obj_Type : Entity_Id;
+ (Aggr : Node_Id;
+ Obj_Type : Entity_Id;
Typ : Entity_Id) return Boolean
is
begin
-- No sliding if the type of the object is not established yet, if it is
-- an unconstrained type whose actual subtype comes from the aggregate,
- -- or if the two types are identical.
+ -- or if the two types are identical. If the aggregate contains only
+ -- an Others_Clause it gets its type from the context and no sliding
+ -- is involved either.
if not Is_Array_Type (Obj_Type) then
return False;
@@ -9633,8 +9637,13 @@ package body Exp_Aggr is
elsif Typ = Obj_Type then
return False;
+ elsif Is_Others_Aggregate (Aggr) then
+ return False;
+
else
-- Sliding can only occur along the first dimension
+ -- If any the bounds of non-static sliding is required
+ -- to force potential range checks.
declare
Bounds1 : constant Range_Nodes :=
@@ -9648,7 +9657,8 @@ package body Exp_Aggr is
not Is_OK_Static_Expression (Bounds1.Last) or else
not Is_OK_Static_Expression (Bounds2.Last)
then
- return False;
+ return True;
+
else
return Expr_Value (Bounds1.First) /= Expr_Value (Bounds2.First)
or else
