[multiple changes]

2009-04-08  Emmanuel Briot  <briot@adacore.com>

	* prj.ads: Update comment on switches file

	* prj-nmsc.adb: Code clean up. Use renaming clauses.

2009-04-08  Robert Dewar  <dewar@adacore.com>

	* exp_ch4.adb (Expand_Concatenate): Further fixes to bounds handling

2009-04-08  Thomas Quinot  <quinot@adacore.com>

	* ali-util.adb: Minor comment fix

2009-04-08  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch8.adb (Analyze_Use_Type): Improve error message when clause
	appears in a context clause, and the enclosing package is mentioned in
	a limited_with_clause.
	(Use_One_Type): Reject clause if type is still incomplete.

From-SVN: r145722

6 files changed, 317 insertions, 195 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 91ac2e5..a18c7d2 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,5 +1,26 @@
 2009-04-08  Emmanuel Briot  <briot@adacore.com>
 
+	* prj.ads: Update comment on switches file
+
+	* prj-nmsc.adb: Code clean up. Use renaming clauses.
+
+2009-04-08  Robert Dewar  <dewar@adacore.com>
+
+	* exp_ch4.adb (Expand_Concatenate): Further fixes to bounds handling
+
+2009-04-08  Thomas Quinot  <quinot@adacore.com>
+
+	* ali-util.adb: Minor comment fix
+
+2009-04-08  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch8.adb (Analyze_Use_Type): Improve error message when clause
+	appears in a context clause, and the enclosing package is mentioned in
+	a limited_with_clause.
+	(Use_One_Type): Reject clause if type is still incomplete.
+
+2009-04-08  Emmanuel Briot  <briot@adacore.com>
+
 	* prj-nmsc.adb (Check_File, Process_Sources_In_Multi_Language_Mode):
 	avoid copies of Source_Data variables when possible, since these
 	involve calls to memcpy() which are done too many times.
diff --git a/gcc/ada/ali-util.adb b/gcc/ada/ali-util.adb
index 322ec5c..25a0d7a 100644
--- a/gcc/ada/ali-util.adb
+++ b/gcc/ada/ali-util.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2007, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2008, 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- --
@@ -490,7 +490,7 @@ package body ALI.Util is
             if not Source.Table (Src).Source_Found
               or else Sdep.Table (D).Stamp /= Source.Table (Src).Stamp
             then
-               --  If -t debug flag set, output time stamp found/expected
+               --  If -dt debug flag set, output time stamp found/expected
 
                if Source.Table (Src).Source_Found and Debug_Flag_T then
                   Write_Str ("Source: """);
diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
index fa8ef46..b01203d 100644
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -2146,8 +2146,13 @@ package body Exp_Ch4 is
       --  Component type. Elements of this component type can appear as one
       --  of the operands of concatenation as well as arrays.
 
-      Ityp : constant Entity_Id := Etype (First_Index (Atyp));
-      --  Index type
+      Istyp : constant Entity_Id := Etype (First_Index (Atyp));
+      --  Index subtype
+
+      Ityp : constant Entity_Id := Base_Type (Istyp);
+      --  Index type. This is the base type of the index subtype, and is used
+      --  for all computed bounds (which may be out of range of Istyp in the
+      --  case of null ranges).
 
       Intyp : Entity_Id;
       --  This is the type we use to do arithmetic to compute the bounds and
@@ -2239,7 +2244,7 @@ package body Exp_Ch4 is
 
       function To_Intyp (X : Node_Id) return Node_Id is
       begin
-         if Base_Type (Ityp) = Base_Type (Intyp) then
+         if Ityp = Base_Type (Intyp) then
             return X;
 
          elsif Is_Enumeration_Type (Ityp) then
@@ -2271,7 +2276,7 @@ package body Exp_Ch4 is
 
          else
             --  If the value is known at compile time, and known to be out of
-            --  range of the index type or the base type, we can signal that
+            --  range of the index subtype or its base type, we can signal that
             --  we are sure to have a constraint error at run time.
 
             --  There are two reasons for doing this. First of all, it is of
@@ -2285,11 +2290,11 @@ package body Exp_Ch4 is
             Analyze_And_Resolve (X);
 
             if Compile_Time_Compare
-                 (X, Type_High_Bound (Ityp),
+                 (X, Type_High_Bound (Istyp),
                   Assume_Valid => False) = GT
               or else
                Compile_Time_Compare
-                 (X, Type_High_Bound (Base_Type (Ityp)),
+                 (X, Type_High_Bound (Ityp),
                   Assume_Valid => False) = GT
             then
                Apply_Compile_Time_Constraint_Error
@@ -2299,7 +2304,7 @@ package body Exp_Ch4 is
                raise Concatenation_Error;
 
             else
-               if Base_Type (Ityp) = Base_Type (Intyp) then
+               if Ityp = Base_Type (Intyp) then
                   return X;
                else
                   return Convert_To (Ityp, X);
@@ -2345,10 +2350,10 @@ package body Exp_Ch4 is
       --  identity type, and for larger unsigned types we use 64-bits.
 
       elsif Is_Modular_Integer_Type (Ityp) then
-         if RM_Size (Base_Type (Ityp)) < RM_Size (Standard_Unsigned) then
+         if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then
             Intyp := Standard_Unsigned;
-         elsif RM_Size (Base_Type (Ityp)) = RM_Size (Standard_Unsigned) then
-            Intyp := Base_Type (Ityp);
+         elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then
+            Intyp := Ityp;
          else
             Intyp := RTE (RE_Long_Long_Unsigned);
          end if;
@@ -2356,10 +2361,10 @@ package body Exp_Ch4 is
       --  Similar treatment for signed types
 
       else
-         if RM_Size (Base_Type (Ityp)) < RM_Size (Standard_Integer) then
+         if RM_Size (Ityp) < RM_Size (Standard_Integer) then
             Intyp := Standard_Integer;
-         elsif RM_Size (Base_Type (Ityp)) = RM_Size (Standard_Integer) then
-            Intyp := Base_Type (Ityp);
+         elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then
+            Intyp := Ityp;
          else
             Intyp := Standard_Long_Long_Integer;
          end if;
@@ -2395,7 +2400,7 @@ package body Exp_Ch4 is
 
             Opnd_Low_Bound (NN) :=
               Make_Attribute_Reference (Loc,
-                Prefix         => New_Reference_To (Ityp, Loc),
+                Prefix         => New_Reference_To (Istyp, Loc),
                 Attribute_Name => Name_First);
 
             Set := True;
diff --git a/gcc/ada/prj-nmsc.adb b/gcc/ada/prj-nmsc.adb
index 8ad0d7e..c00a69a 100644
--- a/gcc/ada/prj-nmsc.adb
+++ b/gcc/ada/prj-nmsc.adb
@@ -50,8 +50,6 @@ with Ada.Strings.Maps.Constants; use Ada.Strings.Maps.Constants;
 
 package body Prj.Nmsc is
 
-   type Source_Data_Access is access Source_Data;
-
    No_Continuation_String : aliased String := "";
    Continuation_String    : aliased String := "\";
    --  Used in Check_Library for continuation error messages at the same
@@ -798,7 +796,6 @@ package body Prj.Nmsc is
             declare
                Language      : Language_Index;
                Source        : Source_Id;
-               Src_Data      : Source_Data_Access;
                Alt_Lang      : Alternate_Language_Id;
                Alt_Lang_Data : Alternate_Language_Data;
                Continuation  : Boolean := False;
@@ -808,23 +805,25 @@ package body Prj.Nmsc is
                while Language /= No_Language_Index loop
                   Source := Data.First_Source;
                   Source_Loop : while Source /= No_Source loop
-                     Src_Data :=
-                       In_Tree.Sources.Table (Source)'Unrestricted_Access;
-
-                     exit Source_Loop when Src_Data.Language = Language;
+                     declare
+                        Src_Data      : Source_Data renames
+                          In_Tree.Sources.Table (Source);
+                     begin
+                        exit Source_Loop when Src_Data.Language = Language;
 
-                     Alt_Lang := Src_Data.Alternate_Languages;
+                        Alt_Lang := Src_Data.Alternate_Languages;
 
-                     Alternate_Loop :
-                     while Alt_Lang /= No_Alternate_Language loop
-                        Alt_Lang_Data :=
-                          In_Tree.Alt_Langs.Table (Alt_Lang);
-                        exit Source_Loop
-                               when Alt_Lang_Data.Language = Language;
-                        Alt_Lang := Alt_Lang_Data.Next;
-                     end loop Alternate_Loop;
+                        Alternate_Loop :
+                        while Alt_Lang /= No_Alternate_Language loop
+                           Alt_Lang_Data :=
+                             In_Tree.Alt_Langs.Table (Alt_Lang);
+                           exit Source_Loop
+                           when Alt_Lang_Data.Language = Language;
+                           Alt_Lang := Alt_Lang_Data.Next;
+                        end loop Alternate_Loop;
 
-                     Source := Src_Data.Next_In_Project;
+                        Source := Src_Data.Next_In_Project;
+                     end;
                   end loop Source_Loop;
 
                   if Source = No_Source then
@@ -2497,7 +2496,6 @@ package body Prj.Nmsc is
       Name    : File_Name_Type;
 
       Source   : Source_Id;
-      Src_Data : Source_Data_Access;
 
       Project_2 : Project_Id;
       Data_2     : Project_Data;
@@ -2513,9 +2511,13 @@ package body Prj.Nmsc is
          loop
             Source := Data_2.First_Source;
             while Source /= No_Source loop
-               Src_Data := In_Tree.Sources.Table (Source)'Unrestricted_Access;
-               Src_Data.In_Interfaces := False;
-               Source := Src_Data.Next_In_Project;
+               declare
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Source);
+               begin
+                  Src_Data.In_Interfaces := False;
+                  Source := Src_Data.Next_In_Project;
+               end;
             end loop;
 
             Project_2 := Data_2.Extends;
@@ -2538,31 +2540,35 @@ package body Prj.Nmsc is
             loop
                Source := Data_2.First_Source;
                while Source /= No_Source loop
-                  Src_Data :=
-                    In_Tree.Sources.Table (Source)'Unrestricted_Access;
-                  if Src_Data.File = Name then
-                     if not Src_Data.Locally_Removed then
-                        Src_Data.In_Interfaces := True;
-                        Src_Data.Declared_In_Interfaces := True;
-
-                        if Src_Data.Other_Part /= No_Source then
-                           In_Tree.Sources.Table
-                             (Src_Data.Other_Part).In_Interfaces := True;
-                           In_Tree.Sources.Table
-                             (Src_Data.Other_Part).Declared_In_Interfaces :=
-                             True;
-                        end if;
+                  declare
+                     Src_Data : Source_Data renames
+                       In_Tree.Sources.Table (Source);
+                  begin
+                     if Src_Data.File = Name then
+                        if not Src_Data.Locally_Removed then
+                           Src_Data.In_Interfaces := True;
+                           Src_Data.Declared_In_Interfaces := True;
 
-                        if Current_Verbosity = High then
-                           Write_Str ("   interface: ");
-                           Write_Line (Get_Name_String (Src_Data.Path.Name));
+                           if Src_Data.Other_Part /= No_Source then
+                              In_Tree.Sources.Table
+                                (Src_Data.Other_Part).In_Interfaces := True;
+                              In_Tree.Sources.Table
+                                (Src_Data.Other_Part).Declared_In_Interfaces :=
+                                True;
+                           end if;
+
+                           if Current_Verbosity = High then
+                              Write_Str ("   interface: ");
+                              Write_Line
+                                (Get_Name_String (Src_Data.Path.Name));
+                           end if;
                         end if;
-                     end if;
 
-                     exit Big_Loop;
-                  end if;
+                        exit Big_Loop;
+                     end if;
 
-                  Source := Src_Data.Next_In_Project;
+                     Source := Src_Data.Next_In_Project;
+                  end;
                end loop;
 
                Project_2 := Data_2.Extends;
@@ -2596,13 +2602,16 @@ package body Prj.Nmsc is
          if Data.Interfaces_Defined then
             Source := Data.First_Source;
             while Source /= No_Source loop
-               Src_Data := In_Tree.Sources.Table (Source)'Unrestricted_Access;
-
-               if not Src_Data.Declared_In_Interfaces then
-                  Src_Data.In_Interfaces := False;
-               end if;
+               declare
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Source);
+               begin
+                  if not Src_Data.Declared_In_Interfaces then
+                     Src_Data.In_Interfaces := False;
+                  end if;
 
-               Source := Src_Data.Next_In_Project;
+                  Source := Src_Data.Next_In_Project;
+               end;
             end loop;
          end if;
       end if;
@@ -3530,7 +3539,6 @@ package body Prj.Nmsc is
       procedure Check_Library (Proj : Project_Id; Extends : Boolean) is
          Proj_Data : Project_Data;
          Src_Id    : Source_Id;
-         Src       : Source_Data_Access;
 
       begin
          if Proj /= No_Project then
@@ -3544,12 +3552,15 @@ package body Prj.Nmsc is
 
                Src_Id := Proj_Data.First_Source;
                while Src_Id /= No_Source loop
-                  Src := In_Tree.Sources.Table (Src_Id)'Unrestricted_Access;
-
-                  exit when Src.Lang_Kind /= File_Based
-                    or else Src.Kind /= Spec;
+                  declare
+                     Src       : Source_Data renames
+                       In_Tree.Sources.Table (Src_Id);
+                  begin
+                     exit when Src.Lang_Kind /= File_Based
+                       or else Src.Kind /= Spec;
 
-                  Src_Id := Src.Next_In_Project;
+                     Src_Id := Src.Next_In_Project;
+                  end;
                end loop;
 
                if Src_Id /= No_Source then
@@ -6413,6 +6424,8 @@ package body Prj.Nmsc is
    is
       Mains : constant Variable_Value :=
                 Prj.Util.Value_Of (Name_Main, Data.Decl.Attributes, In_Tree);
+      List  : String_List_Id;
+      Elem  : String_Element;
 
    begin
       Data.Mains := Mains.Values;
@@ -6433,6 +6446,22 @@ package body Prj.Nmsc is
            (Project, In_Tree,
             "a library project file cannot have Main specified",
             Mains.Location);
+
+      else
+         List := Mains.Values;
+         while List /= Nil_String loop
+            Elem := In_Tree.String_Elements.Table (List);
+
+            if Length_Of_Name (Elem.Value) = 0 then
+               Error_Msg
+                 (Project, In_Tree,
+                  "?a main cannot have an empty name",
+                  Elem.Location);
+               exit;
+            end if;
+
+            List := Elem.Next;
+         end loop;
       end if;
    end Get_Mains;
 
@@ -7366,29 +7395,32 @@ package body Prj.Nmsc is
 
          declare
             Source   : Source_Id;
-            Src_Data : Source_Data_Access;
 
          begin
             Source := Data.First_Source;
             while Source /= No_Source loop
-               Src_Data := In_Tree.Sources.Table (Source)'Unrestricted_Access;
+               declare
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Source);
+               begin
 
-               if Src_Data.Naming_Exception
-                 and then Src_Data.Path = No_Path_Information
-               then
-                  if Src_Data.Unit /= No_Name then
-                     Error_Msg_Name_1 := Name_Id (Src_Data.Display_File);
-                     Error_Msg_Name_2 := Name_Id (Src_Data.Unit);
-                     Error_Msg
-                       (Project, In_Tree,
-                        "source file %% for unit %% not found",
-                        No_Location);
-                  end if;
+                  if Src_Data.Naming_Exception
+                    and then Src_Data.Path = No_Path_Information
+                  then
+                     if Src_Data.Unit /= No_Name then
+                        Error_Msg_Name_1 := Name_Id (Src_Data.Display_File);
+                        Error_Msg_Name_2 := Name_Id (Src_Data.Unit);
+                        Error_Msg
+                          (Project, In_Tree,
+                           "source file %% for unit %% not found",
+                           No_Location);
+                     end if;
 
-                  Remove_Source (Source, No_Source, Project, Data, In_Tree);
-               end if;
+                     Remove_Source (Source, No_Source, Project, Data, In_Tree);
+                  end if;
 
-               Source := Src_Data.Next_In_Project;
+                  Source := Src_Data.Next_In_Project;
+               end;
             end loop;
          end;
 
@@ -8112,10 +8144,10 @@ package body Prj.Nmsc is
             Add_Src := True;
             while Source /= No_Source loop
                declare
-                  Src_Data : constant Source_Data_Access :=
-                    In_Tree.Sources.Table (Source)'Unrestricted_Access;
-               begin
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Source);
 
+               begin
                   if Unit /= No_Name
                     and then Src_Data.Unit = Unit
                     and then
@@ -8129,10 +8161,10 @@ package body Prj.Nmsc is
                          and then Src_Data.Unit = Unit
                          and then
                            (Src_Data.Kind = Kind
-                            or else
-                              (Src_Data.Kind = Sep and then Kind = Impl)
-                            or else
-                              (Src_Data.Kind = Impl and then Kind = Sep)))
+                             or else
+                               (Src_Data.Kind = Sep  and then Kind = Impl)
+                             or else
+                               (Src_Data.Kind = Impl and then Kind = Sep)))
                     or else
                       (Unit = No_Name and then Src_Data.File = File_Name)
                   then
@@ -8437,7 +8469,6 @@ package body Prj.Nmsc is
 
       procedure Process_Sources_In_Multi_Language_Mode is
          Source   : Source_Id;
-         Src_Data : Source_Data_Access;
          Name_Loc : Name_Location;
          OK       : Boolean;
          FF       : File_Found;
@@ -8449,57 +8480,63 @@ package body Prj.Nmsc is
 
          Source := Data.First_Source;
          while Source /= No_Source loop
-            Src_Data := In_Tree.Sources.Table (Source)'Unrestricted_Access;
+            declare
+               Src_Data : Source_Data renames
+                 In_Tree.Sources.Table (Source);
 
-            --  A file that is excluded cannot also be an exception file name
+            begin
+               --  A file that is excluded cannot also be an exception file
+               --  name
 
-            if Excluded_Sources_Htable.Get (Src_Data.File) /=
-              No_File_Found
-            then
-               Error_Msg_File_1 := Src_Data.File;
-               Error_Msg
-                 (Project, In_Tree,
-                  "{ cannot be both excluded and an exception file name",
-                  No_Location);
-            end if;
+               if Excluded_Sources_Htable.Get (Src_Data.File) /=
+                 No_File_Found
+               then
+                  Error_Msg_File_1 := Src_Data.File;
+                  Error_Msg
+                    (Project, In_Tree,
+                     "{ cannot be both excluded and an exception file name",
+                     No_Location);
+               end if;
 
-            Name_Loc := (Name     => Src_Data.File,
-                         Location => No_Location,
-                         Source   => Source,
-                         Except   => Src_Data.Unit /= No_Name,
-                         Found    => False);
+               Name_Loc := (Name     => Src_Data.File,
+                            Location => No_Location,
+                            Source   => Source,
+                            Except   => Src_Data.Unit /= No_Name,
+                            Found    => False);
 
-            if Current_Verbosity = High then
-               Write_Str ("Putting source #");
-               Write_Str (Source'Img);
-               Write_Str (", file ");
-               Write_Str (Get_Name_String (Src_Data.File));
-               Write_Line (" in Source_Names");
-            end if;
+               if Current_Verbosity = High then
+                  Write_Str ("Putting source #");
+                  Write_Str (Source'Img);
+                  Write_Str (", file ");
+                  Write_Str (Get_Name_String (Src_Data.File));
+                  Write_Line (" in Source_Names");
+               end if;
 
-            Source_Names.Set (K => Src_Data.File, E => Name_Loc);
+               Source_Names.Set (K => Src_Data.File, E => Name_Loc);
 
-            --  If this is an Ada exception, record it in table Unit_Exceptions
+               --  If this is an Ada exception, record it in table
+               --  Unit_Exceptions
 
-            if Src_Data.Unit /= No_Name then
-               declare
-                  Unit_Except : Unit_Exception :=
-                                  Unit_Exceptions.Get (Src_Data.Unit);
+               if Src_Data.Unit /= No_Name then
+                  declare
+                     Unit_Except : Unit_Exception :=
+                       Unit_Exceptions.Get (Src_Data.Unit);
 
-               begin
-                  Unit_Except.Name := Src_Data.Unit;
+                  begin
+                     Unit_Except.Name := Src_Data.Unit;
 
-                  if Src_Data.Kind = Spec then
-                     Unit_Except.Spec := Src_Data.File;
-                  else
-                     Unit_Except.Impl := Src_Data.File;
-                  end if;
+                     if Src_Data.Kind = Spec then
+                        Unit_Except.Spec := Src_Data.File;
+                     else
+                        Unit_Except.Impl := Src_Data.File;
+                     end if;
 
-                  Unit_Exceptions.Set (Src_Data.Unit, Unit_Except);
-               end;
-            end if;
+                     Unit_Exceptions.Set (Src_Data.Unit, Unit_Except);
+                  end;
+               end if;
 
-            Source := Src_Data.Next_In_Project;
+               Source := Src_Data.Next_In_Project;
+            end;
          end loop;
 
          Find_Explicit_Sources
@@ -8513,25 +8550,29 @@ package body Prj.Nmsc is
             Source := In_Tree.First_Source;
 
             while Source /= No_Source loop
-               Src_Data := In_Tree.Sources.Table (Source)'Unrestricted_Access;
+               declare
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Source);
 
-               if Src_Data.File = FF.File then
+               begin
+                  if Src_Data.File = FF.File then
 
-                  --  Check that this is from this project or a project that
-                  --  the current project extends.
+                     --  Check that this is from this project or a project that
+                     --  the current project extends.
 
-                  if Src_Data.Project = Project or else
-                    Is_Extending (Project, Src_Data.Project, In_Tree)
-                  then
-                     Src_Data.Locally_Removed := True;
-                     Src_Data.In_Interfaces := False;
-                     Add_Forbidden_File_Name (FF.File);
-                     OK := True;
-                     exit;
+                     if Src_Data.Project = Project or else
+                       Is_Extending (Project, Src_Data.Project, In_Tree)
+                     then
+                        Src_Data.Locally_Removed := True;
+                        Src_Data.In_Interfaces := False;
+                        Add_Forbidden_File_Name (FF.File);
+                        OK := True;
+                        exit;
+                     end if;
                   end if;
-               end if;
 
-               Source := Src_Data.Next_In_Sources;
+                  Source := Src_Data.Next_In_Sources;
+               end;
             end loop;
 
             if not FF.Found and not OK then
@@ -8547,10 +8588,9 @@ package body Prj.Nmsc is
 
          Check_Object_File_Names : declare
             Src_Id      : Source_Id;
-            Src_Data    : Source_Data_Access;
             Source_Name : File_Name_Type;
 
-            procedure Check_Object;
+            procedure Check_Object (Src_Data : Source_Data);
             --  Check if object file name of the current source is already in
             --  hash table Object_File_Names. If it is, report an error. If it
             --  is not, put it there with the file name of the current source.
@@ -8559,7 +8599,7 @@ package body Prj.Nmsc is
             -- Check_Object --
             ------------------
 
-            procedure Check_Object is
+            procedure Check_Object (Src_Data : Source_Data) is
             begin
                Source_Name := Object_File_Names.Get (Src_Data.Object);
 
@@ -8583,54 +8623,60 @@ package body Prj.Nmsc is
             Object_File_Names.Reset;
             Src_Id := In_Tree.First_Source;
             while Src_Id /= No_Source loop
-               Src_Data := In_Tree.Sources.Table (Src_Id)'Unrestricted_Access;
+               declare
+                  Src_Data : Source_Data renames
+                    In_Tree.Sources.Table (Src_Id);
 
-               if Src_Data.Compiled and then Src_Data.Object_Exists
-                 and then Project_Extends (Project, Src_Data.Project, In_Tree)
-               then
-                  if Src_Data.Unit = No_Name then
-                     if Src_Data.Kind = Impl then
-                        Check_Object;
-                     end if;
+               begin
+                  if Src_Data.Compiled and then Src_Data.Object_Exists
+                    and then Project_Extends
+                      (Project, Src_Data.Project, In_Tree)
+                  then
+                     if Src_Data.Unit = No_Name then
+                        if Src_Data.Kind = Impl then
+                           Check_Object (Src_Data);
+                        end if;
 
-                  else
-                     case Src_Data.Kind is
-                        when Spec =>
-                           if Src_Data.Other_Part = No_Source then
-                              Check_Object;
-                           end if;
+                     else
+                        case Src_Data.Kind is
+                           when Spec =>
+                              if Src_Data.Other_Part = No_Source then
+                                 Check_Object (Src_Data);
+                              end if;
 
-                        when Sep =>
-                           null;
+                           when Sep =>
+                              null;
 
-                        when Impl =>
-                           if Src_Data.Other_Part /= No_Source then
-                              Check_Object;
+                           when Impl =>
+                              if Src_Data.Other_Part /= No_Source then
+                                 Check_Object (Src_Data);
 
-                           else
-                              --  Check if it is a subunit
-
-                              declare
-                                 Src_Ind : constant Source_File_Index :=
-                                             Sinput.P.Load_Project_File
-                                               (Get_Name_String
-                                                  (Src_Data.Path.Name));
-
-                              begin
-                                 if Sinput.P.Source_File_Is_Subunit
-                                     (Src_Ind)
-                                 then
-                                    In_Tree.Sources.Table (Src_Id).Kind := Sep;
-                                 else
-                                    Check_Object;
-                                 end if;
-                              end;
-                           end if;
-                     end case;
+                              else
+                                 --  Check if it is a subunit
+
+                                 declare
+                                    Src_Ind : constant Source_File_Index :=
+                                      Sinput.P.Load_Project_File
+                                        (Get_Name_String
+                                             (Src_Data.Path.Name));
+
+                                 begin
+                                    if Sinput.P.Source_File_Is_Subunit
+                                      (Src_Ind)
+                                    then
+                                       In_Tree.Sources.Table (Src_Id).Kind :=
+                                         Sep;
+                                    else
+                                       Check_Object (Src_Data);
+                                    end if;
+                                 end;
+                              end if;
+                        end case;
+                     end if;
                   end if;
-               end if;
 
-               Src_Id := Src_Data.Next_In_Sources;
+                  Src_Id := Src_Data.Next_In_Sources;
+               end;
             end loop;
          end Check_Object_File_Names;
       end Process_Sources_In_Multi_Language_Mode;
diff --git a/gcc/ada/prj.ads b/gcc/ada/prj.ads
index d06138e..18bbd19 100644
--- a/gcc/ada/prj.ads
+++ b/gcc/ada/prj.ads
@@ -725,7 +725,8 @@ package Prj is
       --  Dependency file time stamp
 
       Switches            : File_Name_Type        := No_File;
-      --  File name of the switches file
+      --  File name of the switches file. For all languages, this is a file
+      --  that ends with the .cswi extension.
 
       Switches_Path       : Path_Name_Type        := No_Path;
       --  Path name of the switches file
diff --git a/gcc/ada/sem_ch8.adb b/gcc/ada/sem_ch8.adb
index 88741a4..4fb37ae 100644
--- a/gcc/ada/sem_ch8.adb
+++ b/gcc/ada/sem_ch8.adb
@@ -2515,7 +2515,7 @@ package body Sem_Ch8 is
 
    procedure Analyze_Use_Type (N : Node_Id) is
       E  : Entity_Id;
-      Id : Entity_Id;
+      Id : Node_Id;
 
    begin
       Set_Hidden_By_Use_Clause (N, No_Elist);
@@ -2544,6 +2544,52 @@ package body Sem_Ch8 is
                   Check_In_Previous_With_Clause (N, Prefix (Id));
                end if;
             end if;
+
+         else
+            --  If the use_type_clause appears in a compilation context,
+            --  check whether it comes from a unit that may appear in a
+            --  limited with_clause, for a better error message.
+
+            if Nkind (Parent (N)) = N_Compilation_Unit
+              and then Nkind (Id) /= N_Identifier
+            then
+               declare
+                  Item : Node_Id;
+                  Pref : Node_Id;
+
+                  function Mentioned (Nam : Node_Id) return Boolean;
+                  --  check whether the prefix of expanded name for the
+                  --  type appears in the prefix of some limited_with_clause.
+
+                  function Mentioned (Nam : Node_Id) return Boolean is
+                  begin
+                     if Nkind (Name (Item)) = N_Selected_Component
+                       and then Chars (Prefix (Name (Item))) = Chars (Nam)
+                     then
+                        return True;
+                     else
+                        return False;
+                     end if;
+                  end Mentioned;
+
+               begin
+                  Pref := Prefix (Id);
+                  Item := First (Context_Items (Parent (N)));
+                  while Present (Item)
+                    and then Item /= N
+                  loop
+                     if Nkind (Item) = N_With_Clause
+                       and then Limited_Present (Item)
+                       and then Mentioned (Pref)
+                     then
+                        Change_Error_Text (Get_Msg_Id,
+                           "premature usage of incomplete type");
+                     end if;
+
+                     Next (Item);
+                  end loop;
+               end;
+            end if;
          end if;
 
          Next (Id);
@@ -7064,7 +7110,10 @@ package body Sem_Ch8 is
       Set_Redundant_Use (Id,
         Is_Known_Used or else Is_Potentially_Use_Visible (T));
 
-      if In_Open_Scopes (Scope (T)) then
+      if Ekind (T) = E_Incomplete_Type then
+         Error_Msg_N ("premature usage of incomplete type", Id);
+
+      elsif In_Open_Scopes (Scope (T)) then
          null;
 
       --  A limited view cannot appear in a use_type clause. However, an