[Ada] Removal of technical debt

gcc/ada/

	* exp_ch3.adb (Check_Missing_Others): Add comment.
	(Build_Initialization_Call): Remove inaccurate accessibility
	comment.
	* sem_ch12.adb (Analyze_Generic_Subprogram_Declaration): Remove
	test for Ada2012.
	(Analyze_Package_Instantiation): Remove speculative comment.
	(Inline_Instance_Body): Add comments for loops.
	(Build_Subprogram_Renaming): Remove comment about fix being
	partial and "ugly."
	(Instantiate_Subprogram_Body): Remove comment referencing DEC
	related internal issue.
	(Subtypes_Match): Add comment and simplify anonymous access
	test.
	(Is_Global): Add test for when E is an expanded name, and
	calculate the scope accordingly.
	* sem_ch6.adb (Analyze_Function_Return): Update comment
	regarding accessibility, and add check for
	Warn_On_Ada_2012_Compatibility.
	(Mask_Type_Refs): Add comments.
	(Analyze_Subprogram_Declaration): Remove mysterious suppression
	of elaboration checks.
	* sem_ch7.adb (Preserve_Full_Attributes): Preserve Is_Atomic
	value.
	* sem_ch8.adb (Most_Descendant_Use_Clause): Remove comment.
	(Note_Redundant_Use): Fix calls to Find_First_Use to be
	Find_Most_Prev.
	(Get_Object_Name): Modify error message to be more descriptive.
	(Known_But_Visible): Remove mysterious special case for
	GNAT_Mode.
	(Find_First_Use): Removed.
	(Find_Most_Prev): Renamed from Find_First_Use.
	* sem_prag.adb (Check_Static_Constraint): Add comments to
	routine.

1 files changed, 11 insertions, 22 deletions

diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb
index 8bf309f95f9..68e10afc7cc 100644
--- a/gcc/ada/sem_ch6.adb
+++ b/gcc/ada/sem_ch6.adb
@@ -1535,14 +1535,12 @@ package body Sem_Ch6 is
             --  Check RM 6.5 (5.9/3)
 
             if Has_Aliased then
-               if Ada_Version < Ada_2012 then
-
-                  --  Shouldn't this test Warn_On_Ada_2012_Compatibility ???
-                  --  Can it really happen (extended return???)
-
+               if Ada_Version < Ada_2012
+                 and then Warn_On_Ada_2012_Compatibility
+               then
                   Error_Msg_N
                     ("ALIASED only allowed for limited return objects "
-                     & "in Ada 2012??", N);
+                     & "in Ada 2012?y?", N);
 
                elsif not Is_Limited_View (R_Type) then
                   Error_Msg_N
@@ -1674,9 +1672,9 @@ package body Sem_Ch6 is
                Related_Nod => N);
          end if;
 
-         --  ??? A real run-time accessibility check is needed in cases
-         --  involving dereferences of access parameters. For now we just
-         --  check the static cases.
+         --  Perform static accessibility checks for cases involving
+         --  dereferences of access parameters. Runtime accessibility checks
+         --  get generated elsewhere.
 
          if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L)
            and then Is_Limited_View (Etype (Scope_Id))
@@ -3827,7 +3825,8 @@ package body Sem_Ch6 is
          Result : Elist_Id := No_Elist;
 
          function Mask_Type_Refs (Node : Node_Id) return Traverse_Result;
-         --  Mask all types referenced in the subtree rooted at Node
+         --  Mask all types referenced in the subtree rooted at Node as
+         --  formally frozen.
 
          --------------------
          -- Mask_Type_Refs --
@@ -3835,7 +3834,8 @@ package body Sem_Ch6 is
 
          function Mask_Type_Refs (Node : Node_Id) return Traverse_Result is
             procedure Mask_Type (Typ : Entity_Id);
-            --  ??? what does this do?
+            --  Mask a given type as formally frozen when outside the current
+            --  scope, or else freeze the type.
 
             ---------------
             -- Mask_Type --
@@ -5665,17 +5665,6 @@ package body Sem_Ch6 is
          end;
       end if;
 
-      --  What is the following code for, it used to be
-
-      --  ???   Set_Suppress_Elaboration_Checks
-      --  ???     (Designator, Elaboration_Checks_Suppressed (Designator));
-
-      --  The following seems equivalent, but a bit dubious
-
-      if Elaboration_Checks_Suppressed (Designator) then
-         Set_Kill_Elaboration_Checks (Designator);
-      end if;
-
       --  For a compilation unit, set body required. This flag will only be
       --  reset if a valid Import or Interface pragma is processed later on.