From aef6e234a8a78db39b4ba034cc4c100c07c294a7 Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Fri, 29 May 2020 21:12:21 -0400
Subject: [PATCH] c++: satisfaction value of type typedef to bool [PR95386]

In the testcase below, the satisfaction value of fn1<int>'s constraint
is INTEGER_CST '1' of type BOOLEAN_TYPE value_type, which is a typedef
to the standard boolean_type_node.  But satisfaction_value expects to
see exactly boolean_true_node or integer_one_node, which this value is
neither, causing us to trip over the assert therein.

This patch changes satisfaction_value to accept INTEGER_CST of any
boolean type.

gcc/cp/ChangeLog:

	PR c++/95386
	* constraint.cc (satisfaction_value): Accept INTEGER_CST of any
	boolean type.

gcc/testsuite/ChangeLog:

	PR c++/95386
	* g++.dg/concepts/pr95386.C: New test.
---
 gcc/cp/constraint.cc                    | 14 +++++++-------
 gcc/testsuite/g++.dg/concepts/pr95386.C | 11 +++++++++++
 2 files changed, 18 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/concepts/pr95386.C

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index eb72bfe5936..92ff283013e 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -2490,15 +2490,15 @@ satisfy_disjunction (tree t, tree args, subst_info info)
 tree
 satisfaction_value (tree t)
 {
-  if (t == error_mark_node)
+  if (t == error_mark_node || t == boolean_true_node || t == boolean_false_node)
     return t;
-  if (t == boolean_true_node || t == integer_one_node)
-    return boolean_true_node;
-  if (t == boolean_false_node || t == integer_zero_node)
-    return boolean_false_node;
 
-  /* Anything else should be invalid.  */
-  gcc_assert (false);
+  gcc_assert (TREE_CODE (t) == INTEGER_CST
+	      && same_type_p (TREE_TYPE (t), boolean_type_node));
+  if (integer_zerop (t))
+    return boolean_false_node;
+  else
+    return boolean_true_node;
 }
 
 /* Build a new template argument list with template arguments corresponding
diff --git a/gcc/testsuite/g++.dg/concepts/pr95386.C b/gcc/testsuite/g++.dg/concepts/pr95386.C
new file mode 100644
index 00000000000..3c683e5693c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/concepts/pr95386.C
@@ -0,0 +1,11 @@
+// PR c++/95386
+// { dg-do compile { target concepts } }
+
+template <typename> struct blah {
+ typedef bool value_type;
+ constexpr operator value_type() { return false; }
+};
+
+template <class T> void fn1(T) requires (!blah<T>());
+
+void fn2() { fn1(0); }
-- 
2.30.2