This patch modifies the analysis of aspects Depends and Global. The machinery
can now process renamings of entire objects. Legal renamings are replaced by
the object they rename.
------------
-- Source --
------------
-- renamings.ads
package Renamings
with Abstract_State => (Input_State with Volatile, Input)
is
type Composite_Record is record
Comp : Integer;
end record;
Rec : Composite_Record;
type Composite_Array is array (1 .. 5) of Composite_Record;
Arr : Composite_Array;
-- "entire object" renamings
Ren_1 : Composite_Record renames Rec;
Ren_2 : Composite_Record renames Ren_1;
-- illegal renamings
Ren_3 : Integer renames Rec.Comp;
Ren_4 : Composite_Record renames Arr (3);
Ren_5 : Integer renames Arr (3).Comp;
procedure OK_1
with Global => Ren_1;
procedure OK_2
with Global => Ren_2;
procedure Error_1
with Global => (Rec, Ren_1, Ren_2);
procedure Error_2
with Global => (Ren_3, Ren_4, Ren_5);
end Renamings;
-- replacement.ads
package Replacement is
Obj : Integer;
Ren : Integer renames Obj;
procedure OK_1
with Global => Ren;
function OK_2 return Integer
with Depends => (OK_2'Result => Ren);
end Replacement;
----------------------------
-- Compilation and output --
----------------------------
$ gcc -c -gnat12 -gnatd.V renamings.ads
$ gcc -c -gnat12 -gnatd.V -gnatdg replacement.ads
renamings.ads:27:27: duplicate global item
renamings.ads:27:34: duplicate global item
renamings.ads:29:22: global item must denote variable or state
renamings.ads:29:29: global item must denote variable or state
renamings.ads:29:36: global item must denote variable or state
Source recreated from tree for Replacement (spec)
replacement_E : short_integer := 0;
package replacement is
replacement__obj : integer;
replacement__ren___XR_replacement__obj___XE : _renaming_type;
replacement__ren : integer renames replacement__obj;
procedure replacement__ok_1
with global => ren;
function replacement__ok_2 return integer
with depends => (
replacement__ok_2'result => replacement__obj);
pragma depends ((
replacement__ok_2'result => replacement__obj));
pragma global (replacement__obj);
freeze replacement__ok_1 []
end replacement;
cannot generate code for file replacement.ads (package spec)
Tested on x86_64-pc-linux-gnu, committed on trunk
2013-04-11 Hristian Kirtchev <[email protected]>
* sem_prag.adb (Analyze_Pragma): Both pragma Depends and Global can now
support renamings of entire objects. Legal renamings are replaced by
the object they rename.
(Is_Renaming): New routine.
Index: sem_prag.adb
===================================================================
--- sem_prag.adb (revision 197781)
+++ sem_prag.adb (working copy)
@@ -806,6 +806,9 @@
-- Returns True if pragma appears within the context clause of a unit,
-- and False for any other placement (does not generate any messages).
+ function Is_Renaming (N : Node_Id) return Boolean;
+ -- Determine whether arbitrary node N is a renaming
+
function Is_Static_String_Expression (Arg : Node_Id) return Boolean;
-- Analyzes the argument, and determines if it is a static string
-- expression, returns True if so, False if non-static or not String.
@@ -3013,6 +3016,17 @@
return True;
end Is_In_Context_Clause;
+ -----------------
+ -- Is_Renaming --
+ -----------------
+
+ function Is_Renaming (N : Node_Id) return Boolean is
+ begin
+ return
+ Is_Entity_Name (N)
+ and then Present (Renamed_Object (Entity (N)));
+ end Is_Renaming;
+
---------------------------------
-- Is_Static_String_Expression --
---------------------------------
@@ -9017,8 +9031,8 @@
Null_Seen : in out Boolean)
is
Is_Output : constant Boolean := not Is_Input;
+ Grouped : Node_Id;
Item_Id : Entity_Id;
- Grouped : Node_Id;
begin
-- Multiple input or output items appear as an aggregate
@@ -9106,15 +9120,19 @@
else
Analyze (Item);
- if Is_Entity_Name (Item) then
- Item_Id := Entity_Of (Item);
+ -- Find the entity of the item. If this is a renaming,
+ -- climb the renaming chain to reach the root object.
+ -- Renamings of non-entire objects do not yield an
+ -- entity (Empty).
- if Present (Item_Id)
- and then Ekind_In (Item_Id, E_Abstract_State,
- E_In_Parameter,
- E_In_Out_Parameter,
- E_Out_Parameter,
- E_Variable)
+ Item_Id := Entity_Of (Item);
+
+ if Present (Item_Id) then
+ if Ekind_In (Item_Id, E_Abstract_State,
+ E_In_Parameter,
+ E_In_Out_Parameter,
+ E_Out_Parameter,
+ E_Variable)
then
-- Detect multiple uses of the same state, variable
-- or formal parameter. If this is not the case,
@@ -9148,6 +9166,15 @@
Append_Unique_Elmt (Item_Id, All_Inputs_Seen);
end if;
+ -- When the item renames an entire object, replace
+ -- the item with a reference to the object.
+
+ if Is_Renaming (Item) then
+ Rewrite (Item,
+ New_Reference_To (Item_Id, Sloc (Item)));
+ Analyze (Item);
+ end if;
+
-- All other input/output items are illegal
else
@@ -10809,7 +10836,7 @@
(Item : Node_Id;
Global_Mode : Name_Id)
is
- Id : Entity_Id;
+ Item_Id : Entity_Id;
begin
-- Detect one of the following cases
@@ -10826,13 +10853,18 @@
Analyze (Item);
- if Is_Entity_Name (Item) then
- Id := Entity (Item);
+ -- Find the entity of the item. If this is a renaming, climb
+ -- the renaming chain to reach the root object. Renamings of
+ -- non-entire objects do not yield an entity (Empty).
+ Item_Id := Entity_Of (Item);
+
+ if Present (Item_Id) then
+
-- A global item cannot reference a formal parameter. Do
-- this check first to provide a better error diagnostic.
- if Is_Formal (Id) then
+ if Is_Formal (Item_Id) then
Error_Msg_N
("global item cannot reference formal parameter",
Item);
@@ -10841,14 +10873,23 @@
-- The only legal references are those to abstract states
-- and variables.
- elsif not Ekind_In (Entity (Item), E_Abstract_State,
- E_Variable)
+ elsif not Ekind_In (Item_Id, E_Abstract_State,
+ E_Variable)
then
Error_Msg_N
("global item must denote variable or state", Item);
return;
end if;
+ -- When the item renames an entire object, replace the
+ -- item with a reference to the object.
+
+ if Is_Renaming (Item) then
+ Rewrite (Item,
+ New_Reference_To (Item_Id, Sloc (Item)));
+ Analyze (Item);
+ end if;
+
-- Some form of illegal construct masquerading as a name
else
@@ -10860,7 +10901,7 @@
-- The same entity might be referenced through various way.
-- Check the entity of the item rather than the item itself.
- if Contains (Seen, Id) then
+ if Contains (Seen, Item_Id) then
Error_Msg_N ("duplicate global item", Item);
-- Add the entity of the current item to the list of
@@ -10871,16 +10912,16 @@
Seen := New_Elmt_List;
end if;
- Append_Elmt (Id, Seen);
+ Append_Elmt (Item_Id, Seen);
end if;
- if Ekind (Id) = E_Abstract_State
- and then Is_Volatile_State (Id)
+ if Ekind (Item_Id) = E_Abstract_State
+ and then Is_Volatile_State (Item_Id)
then
-- A global item of mode In_Out or Output cannot denote a
-- volatile Input state.
- if Is_Input_State (Id)
+ if Is_Input_State (Item_Id)
and then (Global_Mode = Name_In_Out
or else
Global_Mode = Name_Output)
@@ -10892,7 +10933,7 @@
-- A global item of mode In_Out or Input cannot reference
-- a volatile Output state.
- elsif Is_Output_State (Id)
+ elsif Is_Output_State (Item_Id)
and then (Global_Mode = Name_In_Out
or else
Global_Mode = Name_Input)
