From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 30 May 2017 07:11:09 +0000 (+0200)
Subject: backport: re PR c++/72868 (Constexpr expressions mistreat case ranges)
X-Git-Tag: releases/gcc-5.5.0~313
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04e5af0b57d5a71ef293ca093f8e531d360a3d90;p=thirdparty%2Fgcc.git

backport: re PR c++/72868 (Constexpr expressions mistreat case ranges)

	Backported from mainline
	2016-08-11  Jakub Jelinek  <jakub@redhat.com>

	PR c++/72868
	* constexpr.c (label_matches): Handle case range expressions.

	* g++.dg/cpp1y/constexpr-switch4.C: New test.

From-SVN: r248595
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8a89f21051b0..167d78e938b1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2017-05-30  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2016-08-11  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/72868
+	* constexpr.c (label_matches): Handle case range expressions.
+
 2017-01-12  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/77812
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index e558e69066ae..4b34b9c9653f 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -3092,6 +3092,12 @@ label_matches (tree *jump_target, tree_stmt_iterator i,
 	{
 	  if (!CASE_LOW (stmt))
 	    default_label = i;
+	  else if (CASE_HIGH (stmt))
+	    {
+	      if (tree_int_cst_le (CASE_LOW (stmt), *jump_target)
+		  && tree_int_cst_le (*jump_target, CASE_HIGH (stmt)))
+		return true;
+	    }
 	  else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt)))
 	    return true;
 	}
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c416f4064992..eccc05634545 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -3,6 +3,9 @@
 	Backported from mainline
 	2016-08-11  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/72868
+	* g++.dg/cpp1y/constexpr-switch4.C: New test.
+
 	PR c/72816
 	* gcc.dg/pr72816.c: Remove dg-error.
 
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-switch4.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-switch4.C
new file mode 100644
index 000000000000..383bde934be8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-switch4.C
@@ -0,0 +1,27 @@
+// PR c++/72868
+// { dg-do compile }
+// { dg-options "-std=gnu++14" }
+
+constexpr int
+foo (int i)
+{
+  switch (i)
+    {
+    case 11 ... 12:
+      return 4;
+    case 0 ... 9:
+      return 3;
+    default:
+      return 7;
+    }
+}
+
+#define SA(X) static_assert((X),#X)
+SA (foo (-1) == 7);
+SA (foo (0) == 3);
+SA (foo (3) == 3);
+SA (foo (9) == 3);
+SA (foo (10) == 7);
+SA (foo (11) == 4);
+SA (foo (12) == 4);
+SA (foo (13) == 7);