re PR middle-end/16558 (bogus missing-return warning)

	PR middle-end/16558
	PR middle-end/19583
	* gimple-low.c (block_may_fallthru): TRY_FINALLY_EXPR only falls
	through if both operands fall through.

From-SVN: r94381

gcc/ChangeLog

+2005-01-28  Ian Lance Taylor  <ian@airs.com>
+
+	PR middle-end/16558
+	PR middle-end/19583
+	* gimple-low.c (block_may_fallthru): TRY_FINALLY_EXPR only falls
+	through if both operands fall through.
+
 2005-01-28  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* cse.c (fold_rtx) <PC>: Don't optimize.
@@ -95,7 +102,7 @@
 	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Only iterate at -O2
 	and better.
 
-2005-01-27  Ian Lance Taylor  <ian@c2micro.com>
+2005-01-27  Ian Lance Taylor  <ian@airs.com>
 
 	PR middle-end/19583
 	* gimple-low.c (try_catch_may_fallthru): New static function.

gcc/gimple-low.c

@@ -348,7 +348,15 @@ block_may_fallthru (tree block)
       return try_catch_may_fallthru (stmt);
 
     case TRY_FINALLY_EXPR:
-      return block_may_fallthru (TREE_OPERAND (stmt, 1));
+      /* The finally clause is always executed after the try clause,
+	 so if it does not fall through, then the try-finally will not
+	 fall through.  Otherwise, if the try clause does not fall
+	 through, then when the finally clause falls through it will
+	 resume execution wherever the try clause was going.  So the
+	 whole try-finally will only fall through if both the try
+	 clause and the finally clause fall through.  */
+      return (block_may_fallthru (TREE_OPERAND (stmt, 0))
+	      && block_may_fallthru (TREE_OPERAND (stmt, 1)));
 
     case MODIFY_EXPR:
       if (TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR)