From fe513fce568f834e1ff24a6ca70fc6dee061013c Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Tue, 19 Dec 2017 10:02:48 +0000
Subject: [PATCH] re PR c++/83116 (Statement with no effect causes wrong code
 of static object constexpr method)

	PR c++/83116
	* constexpr.c (cxx_eval_call_expression): Only look into
	constexpr_call_table if ctx->strict.

	* g++.dg/cpp1y/constexpr-83116.C: New test.

From-SVN: r255813
---
 gcc/cp/ChangeLog                             |  9 +++++++++
 gcc/cp/constexpr.c                           |  2 +-
 gcc/testsuite/g++.dg/cpp1y/constexpr-83116.C | 18 ++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1y/constexpr-83116.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 3c9dc8f4138..d77663a88d4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,12 @@
+2017-12-19  Marek Polacek  <polacek@redhat.com>
+
+	Backported from mainline
+	2017-12-18  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/83116
+	* constexpr.c (cxx_eval_call_expression): Only look into
+	constexpr_call_table if ctx->strict.
+
 2017-12-16  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 327c093a953..9082230b9d5 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1558,7 +1558,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
   tree result = NULL_TREE;
 
   constexpr_call *entry = NULL;
-  if (depth_ok && !non_constant_args)
+  if (depth_ok && !non_constant_args && ctx->strict)
     {
       new_call.hash = iterative_hash_template_arg
 	(new_call.bindings, constexpr_fundef_hasher::hash (new_call.fundef));
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-83116.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-83116.C
new file mode 100644
index 00000000000..18d79e2e1cc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-83116.C
@@ -0,0 +1,18 @@
+// PR c++/83116
+// { dg-do run { target c++14 } }
+// { dg-options "-O2" }
+
+struct S {
+  constexpr S () : s(0) { foo (); }
+  constexpr int foo () { return s; }
+  int s;
+};
+
+int
+main ()
+{
+  static S var;
+  var.s = 5;
+  if (var.s != 5 || var.foo () != 5)
+    __builtin_abort ();
+}