[multiple changes]

2011-09-05  Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_ch6.adb (Move_Activation_Chain): Rewritten. The routine
	no longer needs to search through the entities of the return
	statement scope to find the _chain.
	* sem_ch5.adb: Add with and use clauses for Exp_Ch6 and Sem_Ch6.
	(Analyze_Block_Statement): Add local variable
	Is_BIP_Return_Statement. Add machinery to install all entities
	produced by the expansion of the return object declaration.
	(Install_Return_Entities): New routine.
	* sem_ch6.ads, sem_ch6.adb (Install_Entity): Moved from body to spec.

2011-09-05  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch10.adb (Analyze_Context): Apply simple fixup if context
	of subunit is incomplete.
	(Analyze_Proper_Body): If parent spec is not available, do not
	attempt analysis.

From-SVN: r178549

gcc/ada/ChangeLog

+2011-09-05  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* exp_ch6.adb (Move_Activation_Chain): Rewritten. The routine
+	no longer needs to search through the entities of the return
+	statement scope to find the _chain.
+	* sem_ch5.adb: Add with and use clauses for Exp_Ch6 and Sem_Ch6.
+	(Analyze_Block_Statement): Add local variable
+	Is_BIP_Return_Statement. Add machinery to install all entities
+	produced by the expansion of the return object declaration.
+	(Install_Return_Entities): New routine.
+	* sem_ch6.ads, sem_ch6.adb (Install_Entity): Moved from body to spec.
+
+2011-09-05  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch10.adb (Analyze_Context): Apply simple fixup if context
+	of subunit is incomplete.
+	(Analyze_Proper_Body): If parent spec is not available, do not
+	attempt analysis.
+
 2011-09-05  Ed Schonberg  <schonberg@adacore.com>
 
 	* sem_disp.adb (Find_Controlling_Arg): Add checks for

gcc/ada/exp_ch6.adb

@@ -4645,38 +4645,29 @@ package body Exp_Ch6 is
       ---------------------------
 
       function Move_Activation_Chain return Node_Id is
-         Chain_Formal  : constant Entity_Id :=
-                           Build_In_Place_Formal
-                            (Par_Func, BIP_Activation_Chain);
-         To            : constant Node_Id :=
-                           New_Reference_To (Chain_Formal, Loc);
-         Master_Formal : constant Entity_Id :=
-                           Build_In_Place_Formal (Par_Func, BIP_Master);
-         New_Master    : constant Node_Id :=
-                           New_Reference_To (Master_Formal, Loc);
-
-         Chain_Id : Entity_Id;
-         From     : Node_Id;
-
       begin
-         Chain_Id := First_Entity (Return_Statement_Entity (N));
-         while Chars (Chain_Id) /= Name_uChain loop
-            Chain_Id := Next_Entity (Chain_Id);
-         end loop;
-
-         From :=
-           Make_Attribute_Reference (Loc,
-             Prefix =>
-               New_Reference_To (Chain_Id, Loc),
-             Attribute_Name => Name_Unrestricted_Access);
-         --  ??? Not clear why "Make_Identifier (Loc, Name_uChain)" doesn't
-         --  work, instead of "New_Reference_To (Chain_Id, Loc)" above.
-
          return
            Make_Procedure_Call_Statement (Loc,
              Name                   =>
                New_Reference_To (RTE (RE_Move_Activation_Chain), Loc),
-             Parameter_Associations => New_List (From, To, New_Master));
+
+             Parameter_Associations => New_List (
+
+               --  Source chain
+
+               Make_Attribute_Reference (Loc,
+                 Prefix         => Make_Identifier (Loc, Name_uChain),
+                 Attribute_Name => Name_Unrestricted_Access),
+
+               --  Destination chain
+
+               New_Reference_To
+                 (Build_In_Place_Formal (Par_Func, BIP_Activation_Chain), Loc),
+
+               --  New master
+
+               New_Reference_To
+                 (Build_In_Place_Formal (Par_Func, BIP_Master), Loc)));
       end Move_Activation_Chain;
 
    --  Start of processing for Expand_N_Extended_Return_Statement
@@ -4708,6 +4699,7 @@ package body Exp_Ch6 is
             --  Recover the function body
 
             Func_Bod := Unit_Declaration_Node (Par_Func);
+
             if Nkind (Func_Bod) = N_Subprogram_Declaration then
                Func_Bod := Parent (Parent (Corresponding_Body (Func_Bod)));
             end if;

gcc/ada/sem_ch10.adb

@@ -1650,6 +1650,16 @@ package body Sem_Ch10 is
 
          if Present (Library_Unit (N)) then
             Set_Corresponding_Stub (Unit (Library_Unit (N)), N);
+
+            --  If the subunit has severe errors, the spec of the enclosing
+            --  body may not be available, in which case do not try analysis.
+
+            if Serious_Errors_Detected > 0
+              and then  No (Library_Unit (Library_Unit (N)))
+            then
+               return;
+            end if;
+
             Analyze_Subunit (Library_Unit (N));
 
          --  Otherwise we must load the subunit and link to it
@@ -1990,6 +2000,16 @@ package body Sem_Ch10 is
                      null;
 
                   else
+                     --  If a subunits has serious syntax errors, the context
+                     --  may not have been loaded. Add a harmless unit name to
+                     --  attempt processing.
+
+                     if Serious_Errors_Detected > 0
+                       and then  No (Entity (Name (Item)))
+                     then
+                        Set_Entity (Name (Item), Standard_Standard);
+                     end if;
+
                      Unit_Name := Entity (Name (Item));
                      while Is_Child_Unit (Unit_Name) loop
                         Set_Is_Visible_Child_Unit (Unit_Name);

gcc/ada/sem_ch5.adb

@@ -29,6 +29,7 @@ with Checks;   use Checks;
 with Einfo;    use Einfo;
 with Errout;   use Errout;
 with Expander; use Expander;
+with Exp_Ch6;  use Exp_Ch6;
 with Exp_Util; use Exp_Util;
 with Freeze;   use Freeze;
 with Lib;      use Lib;
@@ -44,6 +45,7 @@ with Sem;      use Sem;
 with Sem_Aux;  use Sem_Aux;
 with Sem_Case; use Sem_Case;
 with Sem_Ch3;  use Sem_Ch3;
+with Sem_Ch6;  use Sem_Ch6;
 with Sem_Ch8;  use Sem_Ch8;
 with Sem_Disp; use Sem_Disp;
 with Sem_Elab; use Sem_Elab;
@@ -836,10 +838,44 @@ package body Sem_Ch5 is
    -----------------------------
 
    procedure Analyze_Block_Statement (N : Node_Id) is
+      procedure Install_Return_Entities (Scop : Entity_Id);
+      --  Install all entities of return statement scope Scop in the visibility
+      --  chain except for the return object since its entity is reused in a
+      --  renaming.
+
+      -----------------------------
+      -- Install_Return_Entities --
+      -----------------------------
+
+      procedure Install_Return_Entities (Scop : Entity_Id) is
+         Id : Entity_Id;
+
+      begin
+         Id := First_Entity (Scop);
+         while Present (Id) loop
+
+            --  Do not install the return object
+
+            if not Ekind_In (Id, E_Constant, E_Variable)
+              or else not Is_Return_Object (Id)
+            then
+               Install_Entity (Id);
+            end if;
+
+            Next_Entity (Id);
+         end loop;
+      end Install_Return_Entities;
+
+      --  Local constants and variables
+
       Decls : constant List_Id := Declarations (N);
       Id    : constant Node_Id := Identifier (N);
       HSS   : constant Node_Id := Handled_Statement_Sequence (N);
 
+      Is_BIP_Return_Statement : Boolean;
+
+   --  Start of processing for Analyze_Block_Statement
+
    begin
       --  In SPARK mode, we reject block statements. Note that the case of
       --  block statements generated by the expander is fine.
@@ -855,6 +891,16 @@ package body Sem_Ch5 is
          return;
       end if;
 
+      --  Detect whether the block is actually a rewritten return statement of
+      --  a build-in-place function.
+
+      Is_BIP_Return_Statement :=
+        Present (Id)
+          and then Present (Entity (Id))
+          and then Ekind (Entity (Id)) = E_Return_Statement
+          and then Is_Build_In_Place_Function
+                     (Return_Applies_To (Entity (Id)));
+
       --  Normal processing with HSS present
 
       declare
@@ -915,6 +961,14 @@ package body Sem_Ch5 is
          Set_Block_Node (Ent, Identifier (N));
          Push_Scope (Ent);
 
+         --  The block served as an extended return statement. Ensure that any
+         --  entities created during the analysis and expansion of the return
+         --  object declaration are once again visible.
+
+         if Is_BIP_Return_Statement then
+            Install_Return_Entities (Ent);
+         end if;
+
          if Present (Decls) then
             Analyze_Declarations (Decls);
             Check_Completion;

gcc/ada/sem_ch6.adb

@@ -181,9 +181,6 @@ package body Sem_Ch6 is
    --  This procedure makes S, a new overloaded entity, into the first visible
    --  entity with that name.
 
-   procedure Install_Entity (E : Entity_Id);
-   --  Make single entity visible (used for generic formals as well)
-
    function Is_Non_Overriding_Operation
      (Prev_E : Entity_Id;
       New_E  : Entity_Id) return Boolean;

gcc/ada/sem_ch6.ads

@@ -179,6 +179,9 @@ package Sem_Ch6 is
    --  Determines if two subtype definitions are fully conformant. Used
    --  for entry family conformance checks (RM 6.3.1 (24)).
 
+   procedure Install_Entity (E : Entity_Id);
+   --  Place a single entity on the visibility chain
+
    procedure Install_Formals (Id : Entity_Id);
    --  On entry to a subprogram body, make the formals visible. Note that
    --  simply placing the subprogram on the scope stack is not sufficient: