[Ada] Fix failing assertions on SPARK elaboration

Checking of SPARK elaboration rules may lead to assertion failures on a
compiler built with assertions. Now fixed.

There is no impact on compilation.

2019-08-14  Yannick Moy  <moy@adacore.com>

gcc/ada/

	* sem_disp.adb (Check_Dispatching_Operation): Update assertion
	for the separate declarations created in GNATprove mode.
	* sem_disp.ads (Is_Overriding_Subprogram): Update comment.
	* sem_elab.adb (SPARK_Processor): Fix test for checking of
	overriding primitives.

From-SVN: r274448

gcc/ada/ChangeLog

+2019-08-14  Yannick Moy  <moy@adacore.com>
+
+	* sem_disp.adb (Check_Dispatching_Operation): Update assertion
+	for the separate declarations created in GNATprove mode.
+	* sem_disp.ads (Is_Overriding_Subprogram): Update comment.
+	* sem_elab.adb (SPARK_Processor): Fix test for checking of
+	overriding primitives.
+
 2019-08-14  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* inline.adb (Add_Inlined_Body): Tweak comments.

gcc/ada/sem_disp.adb

@@ -1149,6 +1149,10 @@ package body Sem_Disp is
          --     overridden primitives. The wrappers include checks on these
          --     modified conditions. (AI12-113).
 
+         --  5. Declarations built for subprograms without separate spec which
+         --     are eligible for inlining in GNATprove (inside
+         --     Sem_Ch6.Analyze_Subprogram_Body_Helper).
+
          if Present (Old_Subp)
            and then Present (Overridden_Operation (Subp))
            and then Is_Dispatching_Operation (Old_Subp)
@@ -1168,7 +1172,9 @@ package body Sem_Disp is
               or else Get_TSS_Name (Subp) = TSS_Stream_Read
               or else Get_TSS_Name (Subp) = TSS_Stream_Write
 
-              or else Present (Contract (Overridden_Operation (Subp))));
+              or else Present (Contract (Overridden_Operation (Subp)))
+
+              or else GNATprove_Mode);
 
             Check_Controlling_Formals (Tagged_Type, Subp);
             Override_Dispatching_Operation (Tagged_Type, Old_Subp, Subp);

gcc/ada/sem_disp.ads

@@ -151,7 +151,8 @@ package Sem_Disp is
    --  Returns True if E is a null procedure that is an interface primitive
 
    function Is_Overriding_Subprogram (E : Entity_Id) return Boolean;
-   --  Returns True if E is an overriding subprogram
+   --  Returns True if E is an overriding subprogram and False otherwise, in
+   --  particular for an inherited subprogram.
 
    function Is_Tag_Indeterminate (N : Node_Id) return Boolean;
    --  Returns true if the expression N is tag-indeterminate. An expression

gcc/ada/sem_elab.adb

@@ -49,6 +49,7 @@ with Sem_Aux;  use Sem_Aux;
 with Sem_Cat;  use Sem_Cat;
 with Sem_Ch7;  use Sem_Ch7;
 with Sem_Ch8;  use Sem_Ch8;
+with Sem_Disp; use Sem_Disp;
 with Sem_Prag; use Sem_Prag;
 with Sem_Util; use Sem_Util;
 with Sinfo;    use Sinfo;
@@ -15233,9 +15234,12 @@ package body Sem_Elab is
          begin
             --  Nothing to do for predefined primitives because they are
             --  artifacts of tagged type expansion and cannot override source
-            --  primitives.
+            --  primitives. Nothing to do as well for inherited primitives as
+            --  the check concerns overridding ones.
 
-            if Is_Predefined_Dispatching_Operation (Prim) then
+            if Is_Predefined_Dispatching_Operation (Prim)
+              or else not Is_Overriding_Subprogram (Prim)
+            then
                return;
             end if;