-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
After : Unit_Id;
R : Succ_Reason;
Ea_Id : Elab_All_Id := No_Elab_All_Link);
- -- Establish a successor link, Before must be elaborated before After,
- -- and the reason for the link is R. Ea_Id is the contents to be placed
- -- in the Elab_All_Link of the entry.
+ -- Establish a successor link, Before must be elaborated before After, and
+ -- the reason for the link is R. Ea_Id is the contents to be placed in the
+ -- Elab_All_Link of the entry.
procedure Choose (Chosen : Unit_Id);
- -- Chosen is the next entry chosen in the elaboration order. This
- -- procedure updates all data structures appropriately.
+ -- Chosen is the next entry chosen in the elaboration order. This procedure
+ -- updates all data structures appropriately.
function Corresponding_Body (U : Unit_Id) return Unit_Id;
pragma Inline (Corresponding_Body);
- -- Given a unit which is a spec for which there is a separate body,
- -- return the unit id of the body. It is an error to call this routine
- -- with a unit that is not a spec, or which does not have a separate body.
+ -- Given a unit which is a spec for which there is a separate body, return
+ -- the unit id of the body. It is an error to call this routine with a unit
+ -- that is not a spec, or which does not have a separate body.
function Corresponding_Spec (U : Unit_Id) return Unit_Id;
pragma Inline (Corresponding_Spec);
- -- Given a unit which is a body for which there is a separate spec,
- -- return the unit id of the spec. It is an error to call this routine
- -- with a unit that is not a body, or which does not have a separate spec.
+ -- Given a unit which is a body for which there is a separate spec, return
+ -- the unit id of the spec. It is an error to call this routine with a unit
+ -- that is not a body, or which does not have a separate spec.
procedure Diagnose_Elaboration_Problem;
-- Called when no elaboration order can be found. Outputs an appropriate
pragma Inline (Is_Body_Unit);
-- Determines if given unit is a body
+ function Is_Pure_Or_Preelab_Unit (U : Unit_Id) return Boolean;
+ -- Returns True if corresponding unit is Pure or Preelaborate. Includes
+ -- dealing with testing flags on spec if it is given a body.
+
function Is_Waiting_Body (U : Unit_Id) return Boolean;
pragma Inline (Is_Waiting_Body);
-- Determines if U is a waiting body, defined as a body which has
Link : Elab_All_Id) return Elab_All_Id;
-- Make an Elab_All_Entries table entry with the given Unam and Link
- function Unit_Id_Of (Uname : Unit_Name_Type) return Unit_Id;
- -- This function uses the Info field set in the names table to obtain
- -- the unit Id of a unit, given its name id value.
-
- function Worse_Choice (U1, U2 : Unit_Id) return Boolean;
+ function Pessimistic_Better_Choice (U1, U2 : Unit_Id) return Boolean;
-- This is like Better_Choice, and has the same interface, but returns
- -- true if U1 is a worse choice than U2 in the sense of the -h (horrible
+ -- true if U1 is a worse choice than U2 in the sense of the -p (pessimistic
-- elaboration order) switch. We still have to obey Ada rules, so it is
-- not quite the direct inverse of Better_Choice.
+ function Unit_Id_Of (Uname : Unit_Name_Type) return Unit_Id;
+ -- This function uses the Info field set in the names table to obtain
+ -- the unit Id of a unit, given its name id value.
+
procedure Write_Dependencies;
-- Write out dependencies (called only if appropriate option is set)
-- Note: the checks here are applied in sequence, and the ordering is
-- significant (i.e. the more important criteria are applied first).
- -- Prefer a waiting body to any other case
+ -- Prefer a waiting body to one that is not a waiting body
if Is_Waiting_Body (U1) and then not Is_Waiting_Body (U2) then
if Debug_Flag_B then
return False;
+ -- Prefer a pure or preelaborable unit to one that is not
+
+ elsif Is_Pure_Or_Preelab_Unit (U1)
+ and then not
+ Is_Pure_Or_Preelab_Unit (U2)
+ then
+ if Debug_Flag_B then
+ Write_Line (" True: u1 is pure/preelab, u2 is not");
+ end if;
+
+ return True;
+
+ elsif Is_Pure_Or_Preelab_Unit (U2)
+ and then not
+ Is_Pure_Or_Preelab_Unit (U1)
+ then
+ if Debug_Flag_B then
+ Write_Line (" False: u2 is pure/preelab, u1 is not");
+ end if;
+
+ return False;
+
-- Prefer a body to a spec
elsif Is_Body_Unit (U1) and then not Is_Body_Unit (U2) then
or else ((not Pessimistic_Elab_Order)
and then Better_Choice (U, Best_So_Far))
or else (Pessimistic_Elab_Order
- and then Worse_Choice (U, Best_So_Far))
+ and then Pessimistic_Better_Choice (U, Best_So_Far))
then
if Debug_Flag_N then
Write_Str (" tentatively chosen (best so far)");
or else Units.Table (U).Utype = Is_Body_Only;
end Is_Body_Unit;
+ -----------------------------
+ -- Is_Pure_Or_Preelab_Unit --
+ -----------------------------
+
+ function Is_Pure_Or_Preelab_Unit (U : Unit_Id) return Boolean is
+ begin
+ -- If we have a body with separate spec, test flags on the spec
+
+ if Units.Table (U).Utype = Is_Body then
+ return Units.Table (U + 1).Preelab
+ or else
+ Units.Table (U + 1).Pure;
+
+ -- Otherwise we have a spec or body acting as spec, test flags on unit
+
+ else
+ return Units.Table (U).Preelab
+ or else
+ Units.Table (U).Pure;
+ end if;
+ end Is_Pure_Or_Preelab_Unit;
+
---------------------
-- Is_Waiting_Body --
---------------------
return Elab_All_Entries.Last;
end Make_Elab_Entry;
- ----------------
- -- Unit_Id_Of --
- ----------------
-
- function Unit_Id_Of (Uname : Unit_Name_Type) return Unit_Id is
- Info : constant Int := Get_Name_Table_Info (Uname);
- begin
- pragma Assert (Info /= 0 and then Unit_Id (Info) /= No_Unit_Id);
- return Unit_Id (Info);
- end Unit_Id_Of;
-
- ------------------
- -- Worse_Choice --
- ------------------
+ -------------------------------
+ -- Pessimistic_Better_Choice --
+ -------------------------------
- function Worse_Choice (U1, U2 : Unit_Id) return Boolean is
+ function Pessimistic_Better_Choice (U1, U2 : Unit_Id) return Boolean is
UT1 : Unit_Record renames Units.Table (U1);
UT2 : Unit_Record renames Units.Table (U2);
begin
+ if Debug_Flag_B then
+ Write_Str ("Pessimistic_Better_Choice (");
+ Write_Unit_Name (UT1.Uname);
+ Write_Str (", ");
+ Write_Unit_Name (UT2.Uname);
+ Write_Line (")");
+ end if;
+
-- Note: the checks here are applied in sequence, and the ordering is
-- significant (i.e. the more important criteria are applied first).
- -- If either unit is internal, then use Better_Choice, since the
- -- language requires that predefined units not mess up in the choice
- -- of elaboration order, and for internal units, any problems are
- -- ours and not the programmers.
+ -- If either unit is predefined or internal, then we use the normal
+ -- Better_Choice rule, since we don't want to disturb the elaboration
+ -- rules of the language with -p, same treatment for Pure/Preelab.
+
+ -- Prefer a predefined unit to a non-predefined unit
- if UT1.Internal or else UT2.Internal then
- return Better_Choice (U1, U2);
+ if UT1.Predefined and then not UT2.Predefined then
+ if Debug_Flag_B then
+ Write_Line (" True: u1 is predefined, u2 is not");
+ end if;
- -- Prefer anything else to a waiting body (!)
+ return True;
+
+ elsif UT2.Predefined and then not UT1.Predefined then
+ if Debug_Flag_B then
+ Write_Line (" False: u2 is predefined, u1 is not");
+ end if;
+
+ return False;
+
+ -- Prefer an internal unit to a non-internal unit
+
+ elsif UT1.Internal and then not UT2.Internal then
+ if Debug_Flag_B then
+ Write_Line (" True: u1 is internal, u2 is not");
+ end if;
+
+ return True;
+
+ elsif UT2.Internal and then not UT1.Internal then
+ if Debug_Flag_B then
+ Write_Line (" False: u2 is internal, u1 is not");
+ end if;
+
+ return False;
+
+ -- Prefer a pure or preelaborable unit to one that is not
+
+ elsif Is_Pure_Or_Preelab_Unit (U1)
+ and then not
+ Is_Pure_Or_Preelab_Unit (U2)
+ then
+ if Debug_Flag_B then
+ Write_Line (" True: u1 is pure/preelab, u2 is not");
+ end if;
+
+ return True;
+
+ elsif Is_Pure_Or_Preelab_Unit (U2)
+ and then not
+ Is_Pure_Or_Preelab_Unit (U1)
+ then
+ if Debug_Flag_B then
+ Write_Line (" False: u2 is pure/preelab, u1 is not");
+ end if;
+
+ return False;
+
+ -- Prefer anything else to a waiting body. We want to make bodies wait
+ -- as long as possible, till we are forced to choose them!
elsif Is_Waiting_Body (U1) and then not Is_Waiting_Body (U2) then
+ if Debug_Flag_B then
+ Write_Line (" False: u1 is waiting body, u2 is not");
+ end if;
+
return False;
elsif Is_Waiting_Body (U2) and then not Is_Waiting_Body (U1) then
+ if Debug_Flag_B then
+ Write_Line (" True: u2 is waiting body, u1 is not");
+ end if;
+
return True;
-- Prefer a spec to a body (!)
elsif Is_Body_Unit (U1) and then not Is_Body_Unit (U2) then
+ if Debug_Flag_B then
+ Write_Line (" False: u1 is body, u2 is not");
+ end if;
+
return False;
elsif Is_Body_Unit (U2) and then not Is_Body_Unit (U1) then
+ if Debug_Flag_B then
+ Write_Line (" True: u2 is body, u1 is not");
+ end if;
+
return True;
-- If both are waiting bodies, then prefer the one whose spec is
-- A before the spec of B if it could. Since it could not, there it
-- must be the case that A depends on B. It is therefore a good idea
-- to put the body of B last so that if there is an elaboration order
- -- problem, we will find it (that's what horrible order is about)
+ -- problem, we will find it (that's what pssimistic order is about)
elsif Is_Waiting_Body (U1) and then Is_Waiting_Body (U2) then
- return
- UNR.Table (Corresponding_Spec (U1)).Elab_Position <
- UNR.Table (Corresponding_Spec (U2)).Elab_Position;
+ declare
+ Result : constant Boolean :=
+ UNR.Table (Corresponding_Spec (U1)).Elab_Position <
+ UNR.Table (Corresponding_Spec (U2)).Elab_Position;
+ begin
+ if Debug_Flag_B then
+ if Result then
+ Write_Line (" True: based on waiting body elab positions");
+ else
+ Write_Line (" False: based on waiting body elab positions");
+ end if;
+ end if;
+
+ return Result;
+ end;
end if;
-- Remaining choice rules are disabled by Debug flag -do
-- as Elaborate_Body_Desirable. In the normal case, we generally want
-- to delay the elaboration of these specs as long as possible, so
-- that bodies have better chance of being elaborated closer to the
- -- specs. Worse_Choice as usual wants to do the opposite and
- -- elaborate such specs as early as possible.
+ -- specs. Pessimistic_Better_Choice as usual wants to do the opposite
+ -- and elaborate such specs as early as possible.
-- If we have two units, one of which is a spec for which this flag
-- is set, and the other is not, we normally prefer to delay the spec
- -- for which the flag is set, and so Worse_Choice does the opposite.
+ -- for which the flag is set, so again Pessimistic_Better_Choice does
+ -- the opposite.
if not UT1.Elaborate_Body_Desirable
and then UT2.Elaborate_Body_Desirable
then
+ if Debug_Flag_B then
+ Write_Line (" False: u1 is elab body desirable, u2 is not");
+ end if;
+
return False;
elsif not UT2.Elaborate_Body_Desirable
and then UT1.Elaborate_Body_Desirable
then
+ if Debug_Flag_B then
+ Write_Line (" True: u1 is elab body desirable, u2 is not");
+ end if;
+
return True;
-- If we have two specs that are both marked as Elaborate_Body
-- desirable, we normally prefer the one whose body is nearer to
-- being able to be elaborated, based on the Num_Pred count. This
-- helps to ensure bodies are as close to specs as possible. As
- -- usual, Worse_Choice does the opposite.
+ -- usual, Pessimistic_Better_Choice does the opposite.
elsif UT1.Elaborate_Body_Desirable
and then UT2.Elaborate_Body_Desirable
then
- return UNR.Table (Corresponding_Body (U1)).Num_Pred >=
- UNR.Table (Corresponding_Body (U2)).Num_Pred;
+ declare
+ Result : constant Boolean :=
+ UNR.Table (Corresponding_Body (U1)).Num_Pred >=
+ UNR.Table (Corresponding_Body (U2)).Num_Pred;
+ begin
+ if Debug_Flag_B then
+ if Result then
+ Write_Line (" True based on Num_Pred compare");
+ else
+ Write_Line (" False based on Num_Pred compare");
+ end if;
+ end if;
+
+ return Result;
+ end;
end if;
end if;
-- If we fall through, it means that no preference rule applies, so we
-- use alphabetical order to at least give a deterministic result. Since
- -- Worse_Choice is in the business of stirring up the order, we will
- -- use reverse alphabetical ordering.
+ -- Pessimistic_Better_Choice is in the business of stirring up the
+ -- order, we will use reverse alphabetical ordering.
+
+ if Debug_Flag_B then
+ Write_Line (" choose on reverse alpha order");
+ end if;
return Uname_Less (UT2.Uname, UT1.Uname);
- end Worse_Choice;
+ end Pessimistic_Better_Choice;
+
+ ----------------
+ -- Unit_Id_Of --
+ ----------------
+
+ function Unit_Id_Of (Uname : Unit_Name_Type) return Unit_Id is
+ Info : constant Int := Get_Name_Table_Info (Uname);
+ begin
+ pragma Assert (Info /= 0 and then Unit_Id (Info) /= No_Unit_Id);
+ return Unit_Id (Info);
+ end Unit_Id_Of;
------------------------
-- Write_Dependencies --
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