fix gcc.dg/switch-2.c

[Geoffrey Keating]

My recent c-semantics.c patch broke gcc.dg/switch-2, as pointed out by
several people.

Tested on powerpc-eabisim.  I have high confidence in it because
Richard Sandiford proposed a nearly-identical patch, thanks Richard!

-- 
- Geoffrey Keating <geoffk@apple.com>

===File ~/patches/gcc-unreachablestkoverflowfix.patch=======
Index: ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ChangeLog,v
retrieving revision 1.17666
diff -u -p -u -p -r1.17666 ChangeLog
--- ChangeLog	2 May 2003 15:27:05 -0000	1.17666
+++ ChangeLog	2 May 2003 18:04:21 -0000
@@ -1,3 +1,8 @@
+2003-05-02  Geoffrey Keating  <geoffk@apple.com>
+
+	* c-semantics.c (genrtl_switch_stmt, genrtl_if_stmt): Call
+	expand_stmt on result of expand_unreachable_stmt.
+
 2003-05-02  Gerald Pfeifer  <pfeifer@dbai.tuwien.ac.at>
 
 	* doc/contrib.texi (Contributors): Add Daniel Berlin.
Index: c-semantics.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-semantics.c,v
retrieving revision 1.57
diff -u -p -u -p -r1.57 c-semantics.c
--- c-semantics.c	1 May 2003 16:13:28 -0000	1.57
+++ c-semantics.c	2 May 2003 18:04:21 -0000
@@ -416,19 +416,20 @@ genrtl_if_stmt (t)
   expand_start_cond (cond, 0);
   if (THEN_CLAUSE (t))
     {
+      tree nextt = THEN_CLAUSE (t);
+      
       if (cond && integer_zerop (cond))
-	expand_unreachable_stmt (THEN_CLAUSE (t), warn_notreached);
-      else
-	expand_stmt (THEN_CLAUSE (t));
+	nextt = expand_unreachable_stmt (nextt, warn_notreached);
+      expand_stmt (nextt);
     }
 
   if (ELSE_CLAUSE (t))
     {
+      tree nextt = ELSE_CLAUSE (t);
       expand_start_else ();
       if (cond && integer_nonzerop (cond))
-	expand_unreachable_stmt (ELSE_CLAUSE (t), warn_notreached);
-      else
-	expand_stmt (ELSE_CLAUSE (t));
+	nextt = expand_unreachable_stmt (nextt, warn_notreached);
+      expand_stmt (nextt);
     }
   expand_end_cond ();
 }
@@ -687,7 +688,7 @@ genrtl_switch_stmt (t)
 
   emit_line_note (input_filename, input_line);
   expand_start_case (1, cond, TREE_TYPE (cond), "switch statement");
-  expand_unreachable_stmt (SWITCH_BODY (t), warn_notreached);
+  expand_stmt (expand_unreachable_stmt (SWITCH_BODY (t), warn_notreached));
   expand_end_case_type (cond, SWITCH_TYPE (t));
 }
 
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