[multiple changes]

2015-10-16  Bob Duff  <duff@adacore.com>

	* debug.adb: Document -gnatdQ switch.

2015-10-16  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch12.adb (Analyze_Formal_Subprogram): Implement rule that
	a formal abstract subprogram cannot have a null default: RM 12.6
	(4 1.2).

From-SVN: r228869

gcc/ada/ChangeLog

 2015-10-16  Bob Duff  <duff@adacore.com>
 
+	* debug.adb: Document -gnatdQ switch.
+
+2015-10-16  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch12.adb (Analyze_Formal_Subprogram): Implement rule that
+	a formal abstract subprogram cannot have a null default: RM 12.6
+	(4 1.2).
+
+2015-10-16  Bob Duff  <duff@adacore.com>
+
 	* sem_util.ads, sinput.ads, bcheck.adb: Minor comment fixes.
 
 2015-10-16  Javier Miranda  <miranda@adacore.com>

gcc/ada/debug.adb

@@ -80,7 +80,7 @@ package body Debug is
    --  dN   No file name information in exception messages
    --  dO   Output immediate error messages
    --  dP   Do not check for controlled objects in preelaborable packages
-   --  dQ
+   --  dQ   Use old secondary stack method
    --  dR   Bypass check for correct version of s-rpc
    --  dS   Never convert numbers to machine numbers in Sem_Eval
    --  dT   Convert to machine numbers only for constant declarations
@@ -430,6 +430,11 @@ package body Debug is
    --       in preelaborable packages, but this restriction is a huge pain,
    --       especially in the predefined library units.
 
+   --  dQ   Use old method for determining what goes on the secondary stack.
+   --       This disables some newer optimizations. The intent is to use this
+   --       temporarily to measure before/after efficiency. ???Remove this
+   --       when we are done (see Sem_Util.Requires_Transient_Scope).
+
    --  dR   Bypass the check for a proper version of s-rpc being present
    --       to use the -gnatz? switch. This allows debugging of the use
    --       of stubs generation without needing to have GLADE (or some

gcc/ada/sem_ch12.adb

@@ -1075,7 +1075,7 @@ package body Sem_Ch12 is
       --  package. As usual an other association must be last in the list.
 
       procedure Check_Overloaded_Formal_Subprogram (Formal : Entity_Id);
-      --  Apply RM 12.3 (9): if a formal subprogram is overloaded, the instance
+      --  Apply RM 12.3(9): if a formal subprogram is overloaded, the instance
       --  cannot have a named association for it. AI05-0025 extends this rule
       --  to formals of formal packages by AI05-0025, and it also applies to
       --  box-initialized formals.
@@ -2820,8 +2820,19 @@ package body Sem_Ch12 is
 
       if Nkind (N) = N_Formal_Abstract_Subprogram_Declaration then
          Set_Is_Abstract_Subprogram (Nam);
+
          Set_Is_Dispatching_Operation (Nam);
 
+         --  A formal abstract procedure cannot have a null default
+         --  (RM 12.6(4 1.2)).
+
+         if Nkind (Spec) = N_Procedure_Specification
+           and then Null_Present (Spec)
+         then
+            Error_Msg_N
+              ("a formal abstract subprogram cannot default to null", Spec);
+         end if;
+
          declare
             Ctrl_Type : constant Entity_Id := Find_Dispatching_Type (Nam);
          begin
@@ -10737,7 +10748,7 @@ package body Sem_Ch12 is
       --  Re-establish the state of information on which checks are suppressed.
       --  This information was set in Body_Info at the point of instantiation,
       --  and now we restore it so that the instance is compiled using the
-      --  check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01).
+      --  check status at the instantiation (RM 11.5(7.2/2), AI95-00224-01).
 
       Local_Suppress_Stack_Top := Body_Info.Local_Suppress_Stack_Top;
       Scope_Suppress           := Body_Info.Scope_Suppress;
@@ -11052,7 +11063,7 @@ package body Sem_Ch12 is
       --  Re-establish the state of information on which checks are suppressed.
       --  This information was set in Body_Info at the point of instantiation,
       --  and now we restore it so that the instance is compiled using the
-      --  check status at the instantiation (RM 11.5 (7.2/2), AI95-00224-01).
+      --  check status at the instantiation (RM 11.5(7.2/2), AI95-00224-01).
 
       Local_Suppress_Stack_Top := Body_Info.Local_Suppress_Stack_Top;
       Scope_Suppress           := Body_Info.Scope_Suppress;
@@ -11970,7 +11981,7 @@ package body Sem_Ch12 is
          --  If the formal and actual types are abstract, check that there
          --  are no abstract primitives of the actual type that correspond to
          --  nonabstract primitives of the formal type (second sentence of
-         --  RM95-3.9.3(9)).
+         --  RM95 3.9.3(9)).
 
          if Is_Abstract_Type (A_Gen_T) and then Is_Abstract_Type (Act_T) then
             Check_Abstract_Primitives : declare