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.

(cherry picked from commit 5ce8961b46f050a96e8c542b34b1cf024ba95f1b)

diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 67c30f380f262986a9ca3081c01590a2ea5a35f4..ae9a029ee5608dd75eb172601bad426f91ac237f 100644 (file)
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -6901,7 +6901,7 @@ 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 (file)
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>();
+}