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 relaxes satisfaction_value to accept any INTEGER_CST which
satisfies integer_zerop or integer_onep. (It seems we could get away
with accepting only INTEGER_CSTs of type BOOLEAN_TYPE, but that wouldn't
be a proper relaxation of what the subroutine currently accepts and
would therefore be more risky to backport.)
Passes 'make check-c++', does this look OK to commit to master and to
the GCC 10 branch after a full bootstrap and regtest?
gcc/cp/ChangeLog:
PR c++/95386
* constraint.cc (satisfaction_value): Relax to accept any
INTEGER_CST that satisfies integer_zerop or integer_onep.
gcc/testsuite/ChangeLog:
PR c++/95386
* g++.dg/concepts/pr95386.C: New test.
---
gcc/cp/constraint.cc | 7 ++++---
gcc/testsuite/g++.dg/concepts/pr95386.C | 11 +++++++++++
2 files changed, 15 insertions(+), 3 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..5a247cfb738 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -2490,11 +2490,12 @@ 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)
+ gcc_assert (TREE_CODE (t) == INTEGER_CST);
+ if (integer_onep (t))
return boolean_true_node;
- if (t == boolean_false_node || t == integer_zero_node)
+ if (integer_zerop (t))
return boolean_false_node;
/* Anything else should be invalid. */
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); }
--
2.27.0.rc1.5.gae92ac8ae3
