ada: Compiler hangs on a semantically incorrect program.

A homonyms list should be acyclic. Do not introduce a cycle in an error case.

gcc/ada/ChangeLog:

	* sem_ch6.adb (Install_Entity): If the entity to be installed is
	already installed, assert that an error has already been flagged
	and then return without introducing a cycle in the entity's
	Homonyms list.

diff --git a/gcc/ada/sem_ch6.adb b/gcc/ada/sem_ch6.adb
index b0eeab5bdb6e3909deeeb35262df71d58c35923b..400c3069f9fdfaf160602513a16f871f8de7676e 100644 (file)
--- a/gcc/ada/sem_ch6.adb
+++ b/gcc/ada/sem_ch6.adb
@@ -10932,9 +10932,14 @@ package body Sem_Ch6 is
    procedure Install_Entity (E : Entity_Id) is
       Prev : constant Entity_Id := Current_Entity (E);
    begin
+      if Prev = E then
+         --  avoid creating a Homonym-list cycle
+         pragma Assert (Serious_Errors_Detected > 0);
+         return;
+      end if;
+
       Set_Is_Immediately_Visible (E);
       Set_Current_Entity (E);
-      pragma Assert (Prev /= E);
       Set_Homonym (E, Prev);
    end Install_Entity;