[multiple changes]

2010-10-08  Robert Dewar  <dewar@adacore.com>

	* sem_util.adb, sem_prag.adb: Minor reformatting

2010-10-08  Hristian Kirtchev  <kirtchev@adacore.com>

	* gnat_rm.texi: Remove the section on pragma Implemented_By_Entry.
	Add section on pragma Implemented.

2010-10-08  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch3.adb (Derive_Subprogram): If an abstract extension has a
	concrete parent with a concrete constructor, the inherited constructor
	is abstract even if the derived type is a null extension.

From-SVN: r165155

gcc/ada/ChangeLog

+2010-10-08  Robert Dewar  <dewar@adacore.com>
+
+	* sem_util.adb, sem_prag.adb: Minor reformatting
+
+2010-10-08  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* gnat_rm.texi: Remove the section on pragma Implemented_By_Entry.
+	Add section on pragma Implemented.
+
+2010-10-08  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch3.adb (Derive_Subprogram): If an abstract extension has a
+	concrete parent with a concrete constructor, the inherited constructor
+	is abstract even if the derived type is a null extension.
+
 2010-10-08  Thomas Quinot  <quinot@adacore.com>
 
 	* sem_ch4.adb: Minor reformatting.

gcc/ada/gnat_rm.texi

@@ -142,7 +142,7 @@ Implementation Defined Pragmas
 * Pragma Finalize_Storage_Only::
 * Pragma Float_Representation::
 * Pragma Ident::
-* Pragma Implemented_By_Entry::
+* Pragma Implemented::
 * Pragma Implicit_Packing::
 * Pragma Import_Exception::
 * Pragma Import_Function::
@@ -760,7 +760,7 @@ consideration, the use of these pragmas should be minimized.
 * Pragma Finalize_Storage_Only::
 * Pragma Float_Representation::
 * Pragma Ident::
-* Pragma Implemented_By_Entry::
+* Pragma Implemented::
 * Pragma Implicit_Packing::
 * Pragma Import_Exception::
 * Pragma Import_Function::
@@ -2474,41 +2474,51 @@ maximum allowed length is 31 characters, so if it is important to
 maintain compatibility with this compiler, you should obey this length
 limit.
 
-@node Pragma Implemented_By_Entry
-@unnumberedsec Pragma Implemented_By_Entry
-@findex Implemented_By_Entry
+@node Pragma Implemented
+@unnumberedsec Pragma Implemented
+@findex Implemented
 @noindent
 Syntax:
 
 @smallexample @c ada
-pragma Implemented_By_Entry (LOCAL_NAME);
+pragma Implemented (procedure_LOCAL_NAME, implementation_kind);
+
+implementation_kind ::= By_Entry | By_Protected_Procedure | By_Any
 @end smallexample
 
 @noindent
-This is a representation pragma which applies to protected, synchronized and
-task interface primitives. If the pragma is applied to primitive operation Op
-of interface Iface, it is illegal to override Op in a type that implements
-Iface, with anything other than an entry.
+This is an Ada 2012 representation pragma which applies to protected, task
+and synchronized interface primitives. The use of pragma Implemented provides
+a way to impose a static requirement on the overriding opreration by adhering
+to one of the three implementation kids: entry, protected procedure or any of
+the above.
 
 @smallexample @c ada
-type Iface is protected interface;
-procedure Do_Something (Object : in out Iface) is abstract;
-pragma Implemented_By_Entry (Do_Something);
+type Synch_Iface is synchronized interface;
+procedure Prim_Op (Obj : in out Iface) is abstract;
+pragma Implemented (Prim_Op, By_Protected_Procedure);
 
-protected type P is new Iface with
-   procedure Do_Something;  --  Illegal
-end P;
+protected type Prot_1 is new Synch_Iface with
+   procedure Prim_Op;  --  Legal
+end Prot_1;
 
-task type T is new Iface with
-   entry Do_Something;      --  Legal
-end T;
+protected type Prot_2 is new Synch_Iface with
+   entry Prim_Op;      --  Illegal
+end Prot_2;
+
+task type Task_Typ is new Synch_Iface with
+   entry Prim_Op;      --  Illegal
+end Task_Typ;
 @end smallexample
 
 @noindent
-NOTE: The pragma is still in its design stage by the Ada Rapporteur Group. It
-is intended to be used in conjunction with dispatching requeue statements as
-described in AI05-0030. Should the ARG decide on an official name and syntax,
-this pragma will become language-defined rather than GNAT-specific.
+When applied to the procedure_or_entry_NAME of a requeue statement, pragma
+Implemented determines the runtime behavior of the requeue. Implementation kind
+By_Entry guarantees that the action of requeueing will procede from an entry to
+another entry. Implementation kind By_Protected_Procedure transforms the
+requeue into a dispatching call, thus eliminating the chance of blocking. Kind
+By_Any shares the behavior of By_Entry and By_Protected_Procedure depending on
+the target's overriding subprogram kind.
 
 @node Pragma Implicit_Packing
 @unnumberedsec Pragma Implicit_Packing

gcc/ada/sem_ch3.adb

@@ -12601,6 +12601,9 @@ package body Sem_Ch3 is
       if Ekind (Parent_Subp) = E_Procedure then
          Set_Is_Valued_Procedure
            (New_Subp, Is_Valued_Procedure (Parent_Subp));
+      else
+         Set_Has_Controlling_Result
+           (New_Subp, Has_Controlling_Result (Parent_Subp));
       end if;
 
       --  No_Return must be inherited properly. If this is overridden in the
@@ -12654,6 +12657,15 @@ package body Sem_Ch3 is
       then
          Set_Is_Abstract_Subprogram (New_Subp);
 
+      --  AI05-0097 : an inherited operation that dispatches on result is
+      --  abstract if the derived type is abstract, even if the parent type
+      --  is concrete and the derived type is a null extension.
+
+      elsif Has_Controlling_Result (Alias (New_Subp))
+        and then Is_Abstract_Type (Etype (New_Subp))
+      then
+         Set_Is_Abstract_Subprogram (New_Subp);
+
       --  Finally, if the parent type is abstract we must verify that all
       --  inherited operations are either non-abstract or overridden, or that
       --  the derived type itself is abstract (this check is performed at the

gcc/ada/sem_prag.adb

@@ -8074,8 +8074,8 @@ package body Sem_Prag is
                return;
             end if;
 
-            --  Ada 2012 (AI05-0030): Implementation_kind "By_Protected_
-            --  Procedure" cannot be applied to the primitive procedure of a
+            --  Ada 2012 (AI05-0030): Cannot apply the Implementation_kind
+            --  "By_Protected_Procedure" to the primitive procedure of a
             --  task interface.
 
             if Chars (Arg2) = Name_By_Protected_Procedure

gcc/ada/sem_util.adb

@@ -5243,10 +5243,8 @@ package body Sem_Util is
 
    function Implementation_Kind (Subp : Entity_Id) return Name_Id is
       Impl_Prag : constant Node_Id := Get_Rep_Pragma (Subp, Name_Implemented);
-
    begin
       pragma Assert (Present (Impl_Prag));
-
       return
         Chars (Expression (Last (Pragma_Argument_Associations (Impl_Prag))));
    end Implementation_Kind;