[multiple changes]

2017-01-13  Javier Miranda  <miranda@adacore.com>

	* einfo.ads (Component_Bit_Offset): Fix documentation.
	* sem_ch13.adb (Check_Record_Representation_Clause): Skip check
	on record holes for components with unknown compile-time offsets.

2017-01-13  Bob Duff  <duff@adacore.com>

	* ali.ads, ali.adb (Static_Elaboration_Model_Used): Remove unused flag.
	* g-locfil.ads: Minor comment fix.

2017-01-13  Bob Duff  <duff@adacore.com>

	* binde.adb (Elab_New): New elaboration order algorithm
	that is expected to cause fewer ABE issues. This is a work in
	progress. The new algorithm is currently disabled, and can be
	enable by the -dp switch, or by modifying the Do_Old and Do_New
	etc. flags and rebuilding. Experimental code is included to
	compare the results of the old and new algorithms.
	* binde.ads: Use GNAT.Dynamic_Tables instead of Table, so we
	can have multiple of these tables, so the old and new algorithms
	can coexist.
	* bindgen.ads (Gen_Output_File): Pass Elab_Order as an 'in'
	parameter of type array. This avoids the global variable, and
	allows bounds checking (which is normally defeated by the tables
	packages). It also ensures that the Elab_Order is read-only
	to Bindgen.
	* bindgen.adb: Pass Elab_Order as an 'in' parameter to all
	subprograms that need it, as above.
	* debug.adb: Document new -dp switch. Modify doc of old -do
	switch.
	* gnatbind.adb (Gnatbind): Make use of new interfaces to Binde
	and Bindgen.  Move writing of closure (-R and -Ra switches)
	to Binde; that's more convenient.

2017-01-13  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch6.adb (Analyze_Expression_Function): If the expression
	function is a completion, all entities referenced in the
	expression are frozen. As a consequence, a reference to an
	uncompleted private type from an enclosing scope is illegal.

From-SVN: r244419

gcc/ada/ChangeLog

 2017-01-13  Javier Miranda  <miranda@adacore.com>
 
+	* einfo.ads (Component_Bit_Offset): Fix documentation.
+	* sem_ch13.adb (Check_Record_Representation_Clause): Skip check
+	on record holes for components with unknown compile-time offsets.
+
+2017-01-13  Bob Duff  <duff@adacore.com>
+
+	* ali.ads, ali.adb (Static_Elaboration_Model_Used): Remove unused flag.
+	* g-locfil.ads: Minor comment fix.
+
+2017-01-13  Bob Duff  <duff@adacore.com>
+
+	* binde.adb (Elab_New): New elaboration order algorithm
+	that is expected to cause fewer ABE issues. This is a work in
+	progress. The new algorithm is currently disabled, and can be
+	enable by the -dp switch, or by modifying the Do_Old and Do_New
+	etc. flags and rebuilding. Experimental code is included to
+	compare the results of the old and new algorithms.
+	* binde.ads: Use GNAT.Dynamic_Tables instead of Table, so we
+	can have multiple of these tables, so the old and new algorithms
+	can coexist.
+	* bindgen.ads (Gen_Output_File): Pass Elab_Order as an 'in'
+	parameter of type array. This avoids the global variable, and
+	allows bounds checking (which is normally defeated by the tables
+	packages). It also ensures that the Elab_Order is read-only
+	to Bindgen.
+	* bindgen.adb: Pass Elab_Order as an 'in' parameter to all
+	subprograms that need it, as above.
+	* debug.adb: Document new -dp switch. Modify doc of old -do
+	switch.
+	* gnatbind.adb (Gnatbind): Make use of new interfaces to Binde
+	and Bindgen.  Move writing of closure (-R and -Ra switches)
+	to Binde; that's more convenient.
+
+2017-01-13  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch6.adb (Analyze_Expression_Function): If the expression
+	function is a completion, all entities referenced in the
+	expression are frozen. As a consequence, a reference to an
+	uncompleted private type from an enclosing scope is illegal.
+
+2017-01-13  Javier Miranda  <miranda@adacore.com>
+
 	* sem_ch6.adb (Freeze_Expr_Types): New subprogram.
 	(Analyze_Subprogram_Body_Helper): At the occurrence of an
 	expression function declaration that is a completion, its

gcc/ada/ali.adb

@@ -116,7 +116,6 @@ package body ALI is
       Partition_Elaboration_Policy_Specified := ' ';
       Queuing_Policy_Specified               := ' ';
       SSO_Default_Specified                  := False;
-      Static_Elaboration_Model_Used          := False;
       Task_Dispatching_Policy_Specified      := ' ';
       Unreserve_All_Interrupts_Specified     := False;
       Frontend_Exceptions_Specified          := False;
@@ -1996,14 +1995,6 @@ package body ALI is
 
          Skip_Eol;
 
-         --  Check if static elaboration model used
-
-         if not Units.Table (Units.Last).Dynamic_Elab
-           and then not Units.Table (Units.Last).Internal
-         then
-            Static_Elaboration_Model_Used := True;
-         end if;
-
          C := Getc;
 
          --  Scan out With lines for this unit

gcc/ada/ali.ads

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, 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- --
@@ -523,11 +523,6 @@ package ALI is
    --  Set to True if at least one ALI file contains '-fstack-check' in its
    --  argument list.
 
-   Static_Elaboration_Model_Used : Boolean := False;
-   --  Set to False by Initialize_ALI. Set to True if any ALI file for a
-   --  non-internal unit compiled with the static elaboration model is
-   --  encountered.
-
    Task_Dispatching_Policy_Specified : Character := ' ';
    --  Set to blank by Initialize_ALI. Set to the appropriate task dispatching
    --  policy character if an ali file contains a P line setting the

gcc/ada/binde.ads

@@ -23,30 +23,38 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
---  This package contains the routines to determine elaboration order
+--  This package contains the routine that determines library-level elaboration
+--  order.
 
 with ALI;   use ALI;
-with Table;
+with Namet; use Namet;
 with Types; use Types;
 
+with GNAT.Dynamic_Tables;
+
 package Binde is
 
-   --  The following table records the chosen elaboration order. It is used
-   --  by Gen_Elab_Calls to generate the sequence of elaboration calls. Note
-   --  that units are included in this table even if they have no elaboration
+   package Unit_Id_Tables is new GNAT.Dynamic_Tables
+     (Table_Component_Type => Unit_Id,
+      Table_Index_Type     => Nat,
+      Table_Low_Bound      => 1,
+      Table_Initial        => 500,
+      Table_Increment      => 200);
+   use Unit_Id_Tables;
+
+   subtype Unit_Id_Table is Unit_Id_Tables.Instance;
+   subtype Unit_Id_Array is Unit_Id_Tables.Table_Type;
+
+   procedure Find_Elab_Order
+     (Elab_Order          : out Unit_Id_Table;
+      First_Main_Lib_File : File_Name_Type);
+   --  Determine elaboration order.
+   --
+   --  The Elab_Order table records the chosen elaboration order. It is used by
+   --  Gen_Elab_Calls to generate the sequence of elaboration calls. Note that
+   --  units are included in this table even if they have no elaboration
    --  routine, since the table is also used to drive the generation of object
    --  files in the binder output. Gen_Elab_Calls skips any units that have no
    --  elaboration routine.
 
-   package Elab_Order is new Table.Table (
-     Table_Component_Type => Unit_Id,
-     Table_Index_Type     => Nat,
-     Table_Low_Bound      => 1,
-     Table_Initial        => 500,
-     Table_Increment      => 200,
-     Table_Name           => "Elab_Order");
-
-   procedure Find_Elab_Order;
-   --  Determine elaboration order
-
 end Binde;

gcc/ada/bindgen.ads

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, 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- --
@@ -32,9 +32,13 @@
 
 --  See the body for exact details of the file that is generated
 
+with Binde; use Binde;
+
 package Bindgen is
 
-   procedure Gen_Output_File (Filename : String);
+   procedure Gen_Output_File
+     (Filename   : String;
+      Elab_Order : Unit_Id_Array);
    --  Filename is the full path name of the binder output file
 
    procedure Set_Bind_Env (Key, Value : String);

gcc/ada/debug.adb

@@ -181,14 +181,14 @@ package body Debug is
    --  dl
    --  dm
    --  dn  List details of manipulation of Num_Pred values
-   --  do  Use old preference for elaboration order
-   --  dp
+   --  do  Use older preference for elaboration order
+   --  dp  Use new preference for elaboration order
    --  dq
    --  dr
    --  ds
    --  dt
    --  du  List units as they are acquired
-   --  dv
+   --  dv  Verbose debugging printouts
    --  dw
    --  dx  Force binder to read xref information from ali files
    --  dy
@@ -809,14 +809,25 @@ package body Debug is
    --      the algorithm used to determine a correct order of elaboration. This
    --      is useful in diagnosing any problems in its behavior.
 
-   --  do  Use old elaboration order preference. The new preference rules
+   --  do  Use older elaboration order preference. The new preference rules
    --      prefer specs with no bodies to specs with bodies, and between two
    --      specs with bodies, prefers the one whose body is closer to being
    --      able to be elaborated. This is a clear improvement, but we provide
    --      this debug flag in case of regressions.
 
+   --  dp  Use new elaboration order preference. The new preference rules
+   --      elaborate all units within a strongly connected component together,
+   --      with no other units in between. In particular, if a spec/body pair
+   --      can be elaborated together, it will be. In the new order, the binder
+   --      behaves as if every pragma Elaborate_All that would be legal is
+   --      present, even if it does not appear in the source code. NOTE: We
+   --      intend to reverse the sense of this switch at some point, so the new
+   --      preference is the default.
+
    --  du  List unit name and file name for each unit as it is read in
 
+   --  dv  Verbose debugging printouts
+
    --  dx  Force the binder to read (and then ignore) the xref information
    --      in ali files (used to check that read circuit is working OK).
 

gcc/ada/einfo.ads

@@ -670,14 +670,13 @@ package Einfo is
 --       stored in a non-standard way, see body for details.
 
 --    Component_Bit_Offset (Uint11)
---       Defined in record components (E_Component, E_Discriminant) if a
---       component clause applies to the component. First bit position of
---       given component, computed from the first bit and position values
---       given in the component clause. A value of No_Uint means that the
---       value is not yet known. The value can be set by the appearance of
---       an explicit component clause in a record representation clause,
---       or it can be set by the front-end in package Layout, or it can be
---       set by the backend. By the time backend processing is completed,
+--       Defined in record components (E_Component, E_Discriminant). First
+--       bit position of given component, computed from the first bit and
+--       position values given in the component clause. A value of No_Uint
+--       means that the value is not yet known. The value can be set by the
+--       appearance of an explicit component clause in a record representation
+--       clause, or it can be set by the front-end in package Layout, or it can
+--       be set by the backend. By the time backend processing is completed,
 --       this field is always set. A negative value is used to represent
 --       a value which is not known at compile time, and must be computed
 --       at run-time (this happens if fields of a record have variable

gcc/ada/g-locfil.ads

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---                     Copyright (C) 1995-2010, AdaCore                     --
+--                     Copyright (C) 1995-2016, AdaCore                     --
 --                                                                          --
 -- 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- --
@@ -39,7 +39,7 @@ package GNAT.Lock_Files is
    --  Exception raised if file cannot be locked
 
    subtype Path_Name is String;
-   --  Pathname is used by all services provided in this unit to specified
+   --  Pathname is used by all services provided in this unit to specify
    --  directory name and file name. On DOS based systems both directory
    --  separators are handled (i.e. slash and backslash).
 

gcc/ada/sem_ch13.adb

@@ -10374,15 +10374,26 @@ package body Sem_Ch13 is
                   Nbit := Sbit;
                   for J in 1 .. Ncomps loop
                      CEnt := Comps (J);
-                     Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
 
-                     if Error_Msg_Uint_1 > 0 then
-                        Error_Msg_NE
-                          ("?H?^-bit gap before component&",
-                           Component_Name (Component_Clause (CEnt)), CEnt);
-                     end if;
+                     declare
+                        CBO : constant Uint := Component_Bit_Offset (CEnt);
+
+                     begin
+                        --  Skip components with unknown offsets
+
+                        if CBO /= No_Uint and then CBO >= 0 then
+                           Error_Msg_Uint_1 := CBO - Nbit;
 
-                     Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
+                           if Error_Msg_Uint_1 > 0 then
+                              Error_Msg_NE
+                                ("?H?^-bit gap before component&",
+                                 Component_Name (Component_Clause (CEnt)),
+                                 CEnt);
+                           end if;
+
+                           Nbit := CBO + Esize (CEnt);
+                        end if;
+                     end;
                   end loop;
 
                   --  Process variant parts recursively if present

gcc/ada/sem_ch6.adb

@@ -274,6 +274,7 @@ package body Sem_Ch6 is
       New_Spec : Node_Id;
       Orig_N   : Node_Id;
       Ret      : Node_Id;
+      Ret_Type : Entity_Id;
 
       Prev : Entity_Id;
       --  If the expression is a completion, Prev is the entity whose
@@ -366,16 +367,34 @@ package body Sem_Ch6 is
       then
          Set_Has_Completion (Prev, False);
          Set_Is_Inlined (Prev);
+         Ret_Type := Etype (Prev);
 
          --  An expression function that is a completion freezes the
-         --  expression. This means freezing the return type, and if it is
-         --  an access type, freezing its designated type as well.
+         --  expression. This means freezing the return type, and if it is an
+         --  access type, freezing its designated type as well.
 
          --  Note that we cannot defer this freezing to the analysis of the
          --  expression itself, because a freeze node might appear in a nested
          --  scope, leading to an elaboration order issue in gigi.
 
-         Freeze_Before (N, Etype (Prev));
+         --  An entity can only be frozen if it has a completion, so we must
+         --  check this explicitly. If it is declared elsewhere it will have
+         --  been frozen already, so only types declared in currently opend
+         --  scopes need to be tested.
+
+         if Ekind (Ret_Type) = E_Private_Type
+           and then In_Open_Scopes (Scope (Ret_Type))
+           and then not Is_Generic_Type (Ret_Type)
+           and then not Is_Frozen (Ret_Type)
+           and then No (Full_View (Ret_Type))
+         then
+            Error_Msg_NE
+              ("premature use of private type&",
+               Result_Definition (Specification (N)), Ret_Type);
+
+         else
+            Freeze_Before (N, Ret_Type);
+         end if;
 
          if Is_Access_Type (Etype (Prev)) then
             Freeze_Before (N, Designated_Type (Etype (Prev)));