exp_util.ads (Find_Prim_Op): Document that Program_Error is raised if no…

exp_util.ads (Find_Prim_Op): Document that Program_Error is raised if no primitive operation is found.

2008-07-30  Robert Dewar  <dewar@adacore.com>

	* exp_util.ads (Find_Prim_Op): Document that Program_Error is raised
	if no primitive operation is found.

	* exp_util.adb: (Find_Prim_Op): Add comments for previous change

From-SVN: r138329

gcc/ada/exp_util.adb

@@ -1582,6 +1582,8 @@ package body Exp_Util is
 
          Next_Elmt (Prim);
 
+         --  Raise Program_Error if no primitive found
+
          if No (Prim) then
             raise Program_Error;
          end if;
@@ -1612,6 +1614,8 @@ package body Exp_Util is
       while not Is_TSS (Node (Prim), Name) loop
          Next_Elmt (Prim);
 
+         --  Raise program error if no primitive found
+
          if No (Prim) then
             raise Program_Error;
          end if;

gcc/ada/exp_util.ads

@@ -360,7 +360,10 @@ package Exp_Util is
    --  Find the first primitive operation of type T whose name is 'Name'.
    --  This function allows the use of a primitive operation which is not
    --  directly visible. If T is a class wide type, then the reference is
-   --  to an operation of the corresponding root type.
+   --  to an operation of the corresponding root type. Raises Program_Error
+   --  exception if no primitive operation is found. This is normally an
+   --  internal error, but in some cases is an expected consequence of
+   --  illegalities elsewhere.
 
    function Find_Prim_Op
      (T    : Entity_Id;
@@ -370,6 +373,9 @@ package Exp_Util is
    --  with the indicated suffix). This function allows use of a primitive
    --  operation which is not directly visible. If T is a class wide type,
    --  then the reference is to an operation of the corresponding root type.
+   --  Raises Program_Error exception if no primitive operation is found.
+   --  This is normally an internal error, but in some cases is an expected
+   --  consequence of illegalities elsewhere.
 
    function Find_Protection_Object (Scop : Entity_Id) return Entity_Id;
    --  Traverse the scope stack starting from Scop and look for an entry,