c++: ICE with -Wlogical-op [PR107755]

Here we crash in the middle end because warn_logical_operator calls
build_range_check which calls various fold_* functions and those
don't work too well when we're still processing template trees.  For
instance here we crash because we're converting a RECORD_TYPE to bool.
At this point VIEW_CONVERT_EXPR<struct Foo>(b) hasn't yet been converted
to Foo::operator bool (&b).

I was excited to fix this with instantiation_dependent_expression_p
which can now be called from c-family/ as well, but the problem isn't
that the expression is dependent.  So, p_t_d it is.

	PR c++/107755

gcc/cp/ChangeLog:

	* call.cc (build_new_op): Don't call warn_logical_operator when
	processing a template.

gcc/testsuite/ChangeLog:

	* g++.dg/warn/Wlogical-op-4.C: New test.

2 files changed, 24 insertions, 1 deletions

diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 5715a7c..f7c5d9d 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -7335,7 +7335,7 @@ build_new_op (const op_location_t &loc, enum tree_code code, int flags,
     case TRUTH_ORIF_EXPR:
     case TRUTH_AND_EXPR:
     case TRUTH_OR_EXPR:
-      if (complain & tf_warning)
+      if ((complain & tf_warning) && !processing_template_decl)
 	warn_logical_operator (loc, code, boolean_type_node,
 			       code_orig_arg1, arg1,
 			       code_orig_arg2, arg2);
diff --git a/gcc/testsuite/g++.dg/warn/Wlogical-op-4.C b/gcc/testsuite/g++.dg/warn/Wlogical-op-4.C
new file mode 100644
index 0000000..745c911
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wlogical-op-4.C
@@ -0,0 +1,23 @@
+// PR c++/107755
+// { dg-do compile }
+// { dg-options "-Wlogical-op" }
+
+struct Foo
+{
+  operator bool() const { return false; }
+};
+
+bool a;
+Foo b;
+
+template <typename ignored>
+static bool Bar()
+{
+  return (true && (false ? a : b));
+  return (false || (false ? a : b));
+}
+
+bool Baz()
+{
+  return Bar<void>();
+}