From: Jason Merrill <jason@redhat.com>
Date: Thu, 21 Jul 2016 06:05:51 +0000 (-0400)
Subject: PR c++/71896 - constexpr pointer-to-member comparison.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=dd5dda561e34151f0145d0c0ceabf4d4a14509a3;p=gcc.git

PR c++/71896 - constexpr pointer-to-member comparison.

	* constexpr.c (cxx_eval_binary_expression): Handle comparison
	between lowered and unlowered PTRMEM_CST.

From-SVN: r238562
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index be223f2c177..78487eac174 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2016-07-21  Jason Merrill  <jason@redhat.com>
 
+	PR c++/71896
+	* constexpr.c (cxx_eval_binary_expression): Handle comparison
+	between lowered and unlowered PTRMEM_CST.
+
 	PR c++/65168
 	* typeck.c (cp_truthvalue_conversion): Compare pointers to nullptr.
 	Don't set c_inhibit_evaluation_warnings.
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 346fdfad908..240c606f82c 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1838,6 +1838,10 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t,
 	       && (null_member_pointer_value_p (lhs)
 		   || null_member_pointer_value_p (rhs)))
 	r = constant_boolean_node (!is_code_eq, type);
+      else if (TREE_CODE (lhs) == PTRMEM_CST)
+	lhs = cplus_expand_constant (lhs);
+      else if (TREE_CODE (rhs) == PTRMEM_CST)
+	rhs = cplus_expand_constant (rhs);
     }
 
   if (r == NULL_TREE)
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem6.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem6.C
new file mode 100644
index 00000000000..ed18ab1a630
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-ptrmem6.C
@@ -0,0 +1,13 @@
+// PR c++/71896
+// { dg-do compile { target c++11 } }
+
+struct Foo {
+  int x;
+};
+
+constexpr bool compare(int Foo::*t) { return t == &Foo::x; }
+
+constexpr bool b = compare(&Foo::x);
+
+#define SA(X) static_assert ((X),#X)
+SA(b);