C++ PATCH to fix ICE with -Wbool-operation (PR c++/82040)

[Marek Polacek <polacek@redhat.com>]

Here we got into re-entering the error reporting routines because the
warning_at call wasn't guarded with "complain", and crash ensued.

Bootstrapped/regtested on x86_64-linux, ok for trunk/7?

2017-08-31  Marek Polacek  <polacek@redhat.com>

	PR c++/82040
	* typeck.c (cp_build_unary_op): Avoid re-entering reporting routines.

	* g++.dg/warn/Wbool-operation-1.C: New test.

diff --git gcc/cp/typeck.c gcc/cp/typeck.c
index 171c2dfb57c..b303ceaede1 100644
--- gcc/cp/typeck.c
+++ gcc/cp/typeck.c
@@ -5982,6 +5982,7 @@ cp_build_unary_op (enum tree_code code, tree xarg, bool noconvert,
 	{
 	  /* Warn if the expression has boolean value.  */
 	  if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE
+	      && (complain & tf_error)
 	      && warning_at (location, OPT_Wbool_operation,
 			     "%<~%> on an expression of type bool"))
 	    inform (location, "did you mean to use logical not (%<!%>)?");
diff --git gcc/testsuite/g++.dg/warn/Wbool-operation-1.C gcc/testsuite/g++.dg/warn/Wbool-operation-1.C
index e69de29bb2d..4512b858287 100644
--- gcc/testsuite/g++.dg/warn/Wbool-operation-1.C
+++ gcc/testsuite/g++.dg/warn/Wbool-operation-1.C
@@ -0,0 +1,11 @@
+// PR c++/82040
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wbool-operation" }
+
+template <class c>
+decltype (~c{})
+call ()
+{
+  return ~false; // { dg-warning "on an expression of type bool" }
+}
+template int call<bool>();

	Marek