From d23f04a165d7682fc09f5944cac66a7895e48dfe Mon Sep 17 00:00:00 2001
From: Michael Ilseman <milseman@apple.com>
Date: Thu, 20 Nov 2014 19:33:33 +0000
Subject: [PATCH] Compilation test for PostOrderIterator.

If the template specialization for externally managed sets in
PostOrderIterator call too far out of sync with each other, this unit
test will fail to build. This is especially useful for developers who
may not build Clang (the only in-tree user) every time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222447 91177308-0d34-0410-b5e6-96231b3b80d8
---
 unittests/ADT/CMakeLists.txt            |  1 +
 unittests/ADT/PostOrderIteratorTest.cpp | 37 +++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 unittests/ADT/PostOrderIteratorTest.cpp

diff --git a/unittests/ADT/CMakeLists.txt b/unittests/ADT/CMakeLists.txt
index 845e8058200..d899852325c 100644
--- a/unittests/ADT/CMakeLists.txt
+++ b/unittests/ADT/CMakeLists.txt
@@ -27,6 +27,7 @@ set(ADTSources
   PackedVectorTest.cpp
   PointerIntPairTest.cpp
   PointerUnionTest.cpp
+  PostOrderIteratorTest.cpp
   SCCIteratorTest.cpp
   SmallPtrSetTest.cpp
   SmallStringTest.cpp
diff --git a/unittests/ADT/PostOrderIteratorTest.cpp b/unittests/ADT/PostOrderIteratorTest.cpp
new file mode 100644
index 00000000000..1da1078c749
--- /dev/null
+++ b/unittests/ADT/PostOrderIteratorTest.cpp
@@ -0,0 +1,37 @@
+//===- PostOrderIteratorTest.cpp - PostOrderIterator unit tests -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "gtest/gtest.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/CFG.h"
+using namespace llvm;
+
+namespace {
+
+// Whether we're able to compile
+TEST(PostOrderIteratorTest, Compiles) {
+  typedef SmallPtrSet<void *, 4> ExtSetTy;
+
+  // Tests that template specializations are kept up to date
+  void *Null = nullptr;
+  po_iterator_storage<std::set<void *>, false> PIS;
+  PIS.insertEdge(Null, Null);
+  ExtSetTy Ext;
+  po_iterator_storage<ExtSetTy, true> PISExt(Ext);
+  PIS.insertEdge(Null, Null);
+
+  // Test above, but going through po_iterator (which inherits from template
+  // base)
+  BasicBlock *NullBB = nullptr;
+  auto PI = po_end(NullBB);
+  PI.insertEdge(NullBB, NullBB);
+  auto PIExt = po_ext_end(NullBB, Ext);
+  PIExt.insertEdge(NullBB, NullBB);
+}
+}
-- 
2.34.1