This patch updates the freezing of expressions to account for a case when the
freezing expression is part of the Actions list of a N_Expression_With_Actions
node. In this case, any freeze nodes must remain in the Actions list.
------------
-- Source --
------------
-- use_before_decl.adb
with Ada.Text_IO; use Ada.Text_IO;
procedure Use_Before_Decl is
type String_Ptr is access all String;
type String_Ptr_Array is array (Positive range <>) of String_Ptr;
pragma Pack (String_Ptr_Array);
type String_Ptr_Array_Ptr is access all String_Ptr_Array;
procedure Print (Data : String_Ptr_Array_Ptr) is
begin
if Data = null then
Put_Line ("Empty");
else
for Index in Data.all'Range loop
if Data.all (Index) /= null
and then Data.all (Index).all'Length > 0
then
Put_Line (Data.all (Index).all);
end if;
end loop;
end if;
end Print;
Data : String_Ptr_Array_Ptr;
begin
Data := new String_Ptr_Array (1 .. 3);
for Index in Data.all'Range loop
Data.all (Index) := new String'("Value" & Index'Img);
end loop;
Print (Data);
end Use_Before_Decl;
----------------------------
-- Compilation and output --
----------------------------
$ gnatmake -q use_before_decl.adb
$ ./use_before_decl
Value 1
Value 2
Value 3
Tested on x86_64-pc-linux-gnu, committed on trunk
2014-07-31 Hristian Kirtchev <kirtc...@adacore.com>
* freeze.adb (Freeze_Expression): Update the loop in charge
of finding a proper insertion place for freeze nodes to handle
N_Expression_With_Actions nodes.
Index: freeze.adb
===================================================================
--- freeze.adb (revision 213332)
+++ freeze.adb (revision 213333)
@@ -6143,14 +6143,27 @@
exit when Is_List_Member (P);
- -- Note: The N_Loop_Statement is a special case. A type that
- -- appears in the source can never be frozen in a loop (this
- -- occurs only because of a loop expanded by the expander), so we
- -- keep on going. Otherwise we terminate the search. Same is true
- -- of any entity which comes from source. (if they have predefined
- -- type, that type does not appear to come from source, but the
- -- entity should not be frozen here).
+ -- Freeze nodes produced by an expression coming from the Actions
+ -- list of a N_Expression_With_Actions node must remain within the
+ -- Actions list. Inserting the freeze nodes further up the tree
+ -- may lead to use before declaration issues in the case of array
+ -- types.
+ when N_Expression_With_Actions =>
+ if Is_List_Member (P)
+ and then List_Containing (P) = Actions (Parent_P)
+ then
+ exit;
+ end if;
+
+ -- Note: N_Loop_Statement is a special case. A type that appears
+ -- in the source can never be frozen in a loop (this occurs only
+ -- because of a loop expanded by the expander), so we keep on
+ -- going. Otherwise we terminate the search. Same is true of any
+ -- entity which comes from source. (if they have predefined type,
+ -- that type does not appear to come from source, but the entity
+ -- should not be frozen here).
+
when N_Loop_Statement =>
exit when not Comes_From_Source (Etype (N))
and then (No (Nam) or else not Comes_From_Source (Nam));
