llvm/unittests/IR/MetadataTest.cpp - toolchain/llvm-project - Gitiles

 //===- llvm/unittest/IR/Metadata.cpp - Metadata unit tests ----------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/Support/raw_ostream.h"
 #include "gtest/gtest.h"
 using namespace llvm;

 namespace {

 class MetadataTest : public testing::Test {
 protected:
   LLVMContext Context;
   MDNode *getNode() { return MDNode::get(Context, None); }
   MDNode *getNode(Metadata *MD) { return MDNode::get(Context, MD); }
   MDNode *getNode(Metadata *MD1, Metadata *MD2) {
     Metadata *MDs[] = {MD1, MD2};
     return MDNode::get(Context, MDs);
   }
 };
 typedef MetadataTest MDStringTest;

 // Test that construction of MDString with different value produces different
 // MDString objects, even with the same string pointer and nulls in the string.
 TEST_F(MDStringTest, CreateDifferent) {
   char x[3] = { 'f', 0, 'A' };
   MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
   x[2] = 'B';
   MDString *s2 = MDString::get(Context, StringRef(&x[0], 3));
   EXPECT_NE(s1, s2);
 }

 // Test that creation of MDStrings with the same string contents produces the
 // same MDString object, even with different pointers.
 TEST_F(MDStringTest, CreateSame) {
   char x[4] = { 'a', 'b', 'c', 'X' };
   char y[4] = { 'a', 'b', 'c', 'Y' };

   MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
   MDString *s2 = MDString::get(Context, StringRef(&y[0], 3));
   EXPECT_EQ(s1, s2);
 }

 // Test that MDString prints out the string we fed it.
 TEST_F(MDStringTest, PrintingSimple) {
   char *str = new char[13];
   strncpy(str, "testing 1 2 3", 13);
   MDString *s = MDString::get(Context, StringRef(str, 13));
   strncpy(str, "aaaaaaaaaaaaa", 13);
   delete[] str;

   std::string Str;
   raw_string_ostream oss(Str);
   s->print(oss);
   EXPECT_STREQ("!\"testing 1 2 3\"", oss.str().c_str());
 }

 // Test printing of MDString with non-printable characters.
 TEST_F(MDStringTest, PrintingComplex) {
   char str[5] = {0, '\n', '"', '\\', (char)-1};
   MDString *s = MDString::get(Context, StringRef(str+0, 5));
   std::string Str;
   raw_string_ostream oss(Str);
   s->print(oss);
   EXPECT_STREQ("!\"\\00\\0A\\22\\5C\\FF\"", oss.str().c_str());
 }

 typedef MetadataTest MDNodeTest;

 // Test the two constructors, and containing other Constants.
 TEST_F(MDNodeTest, Simple) {
   char x[3] = { 'a', 'b', 'c' };
   char y[3] = { '1', '2', '3' };

   MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
   MDString *s2 = MDString::get(Context, StringRef(&y[0], 3));
   ConstantAsMetadata *CI = ConstantAsMetadata::get(
       ConstantInt::get(getGlobalContext(), APInt(8, 0)));

   std::vector<Metadata *> V;
   V.push_back(s1);
   V.push_back(CI);
   V.push_back(s2);

   MDNode *n1 = MDNode::get(Context, V);
   Metadata *const c1 = n1;
   MDNode *n2 = MDNode::get(Context, c1);
   Metadata *const c2 = n2;
   MDNode *n3 = MDNode::get(Context, V);
   MDNode *n4 = MDNode::getIfExists(Context, V);
   MDNode *n5 = MDNode::getIfExists(Context, c1);
   MDNode *n6 = MDNode::getIfExists(Context, c2);
   EXPECT_NE(n1, n2);
   EXPECT_EQ(n1, n3);
   EXPECT_EQ(n4, n1);
   EXPECT_EQ(n5, n2);
   EXPECT_EQ(n6, (Metadata *)nullptr);

   EXPECT_EQ(3u, n1->getNumOperands());
   EXPECT_EQ(s1, n1->getOperand(0));
   EXPECT_EQ(CI, n1->getOperand(1));
   EXPECT_EQ(s2, n1->getOperand(2));

   EXPECT_EQ(1u, n2->getNumOperands());
   EXPECT_EQ(n1, n2->getOperand(0));
 }

 TEST_F(MDNodeTest, Delete) {
   Constant *C = ConstantInt::get(Type::getInt32Ty(getGlobalContext()), 1);
   Instruction *I = new BitCastInst(C, Type::getInt32Ty(getGlobalContext()));

   Metadata *const V = LocalAsMetadata::get(I);
   MDNode *n = MDNode::get(Context, V);
   TrackingMDRef wvh(n);

   EXPECT_EQ(n, wvh);

   delete I;
 }

 TEST_F(MDNodeTest, SelfReference) {
   // !0 = !{!0}
   // !1 = !{!0}
   {
     MDNode *Temp = MDNode::getTemporary(Context, None);
     Metadata *Args[] = {Temp};
     MDNode *Self = MDNode::get(Context, Args);
     Self->replaceOperandWith(0, Self);
     MDNode::deleteTemporary(Temp);
     ASSERT_EQ(Self, Self->getOperand(0));

     // Self-references should be distinct, so MDNode::get() should grab a
     // uniqued node that references Self, not Self.
     Args[0] = Self;
     MDNode *Ref1 = MDNode::get(Context, Args);
     MDNode *Ref2 = MDNode::get(Context, Args);
     EXPECT_NE(Self, Ref1);
     EXPECT_EQ(Ref1, Ref2);
   }

   // !0 = !{!0, !{}}
   // !1 = !{!0, !{}}
   {
     MDNode *Temp = MDNode::getTemporary(Context, None);
     Metadata *Args[] = {Temp, MDNode::get(Context, None)};
     MDNode *Self = MDNode::get(Context, Args);
     Self->replaceOperandWith(0, Self);
     MDNode::deleteTemporary(Temp);
     ASSERT_EQ(Self, Self->getOperand(0));

     // Self-references should be distinct, so MDNode::get() should grab a
     // uniqued node that references Self, not Self itself.
     Args[0] = Self;
     MDNode *Ref1 = MDNode::get(Context, Args);
     MDNode *Ref2 = MDNode::get(Context, Args);
     EXPECT_NE(Self, Ref1);
     EXPECT_EQ(Ref1, Ref2);
   }
 }

 TEST_F(MDNodeTest, Print) {
   Constant *C = ConstantInt::get(Type::getInt32Ty(Context), 7);
   MDString *S = MDString::get(Context, "foo");
   MDNode *N0 = getNode();
   MDNode *N1 = getNode(N0);
   MDNode *N2 = getNode(N0, N1);

   Metadata *Args[] = {ConstantAsMetadata::get(C), S, nullptr, N0, N1, N2};
   MDNode *N = MDNode::get(Context, Args);

   std::string Expected;
   {
     raw_string_ostream OS(Expected);
     OS << "!{";
     C->printAsOperand(OS);
     OS << ", ";
     S->printAsOperand(OS);
     OS << ", null";
     MDNode *Nodes[] = {N0, N1, N2};
     for (auto *Node : Nodes)
       OS << ", <" << (void *)Node << ">";
     OS << "}\n";
   }

   std::string Actual;
   {
     raw_string_ostream OS(Actual);
     N->print(OS);
   }

   EXPECT_EQ(Expected, Actual);
 }

 TEST_F(MDNodeTest, NullOperand) {
   // metadata !{}
   MDNode *Empty = MDNode::get(Context, None);

   // metadata !{metadata !{}}
   Metadata *Ops[] = {Empty};
   MDNode *N = MDNode::get(Context, Ops);
   ASSERT_EQ(Empty, N->getOperand(0));

   // metadata !{metadata !{}} => metadata !{null}
   N->replaceOperandWith(0, nullptr);
   ASSERT_EQ(nullptr, N->getOperand(0));

   // metadata !{null}
   Ops[0] = nullptr;
   MDNode *NullOp = MDNode::get(Context, Ops);
   ASSERT_EQ(nullptr, NullOp->getOperand(0));
   EXPECT_EQ(N, NullOp);
 }

 typedef MetadataTest MetadataAsValueTest;

 TEST_F(MetadataAsValueTest, MDNode) {
   MDNode *N = MDNode::get(Context, None);
   auto *V = MetadataAsValue::get(Context, N);
   EXPECT_TRUE(V->getType()->isMetadataTy());
   EXPECT_EQ(N, V->getMetadata());

   auto *V2 = MetadataAsValue::get(Context, N);
   EXPECT_EQ(V, V2);
 }

 TEST_F(MetadataAsValueTest, MDNodeMDNode) {
   MDNode *N = MDNode::get(Context, None);
   Metadata *Ops[] = {N};
   MDNode *N2 = MDNode::get(Context, Ops);
   auto *V = MetadataAsValue::get(Context, N2);
   EXPECT_TRUE(V->getType()->isMetadataTy());
   EXPECT_EQ(N2, V->getMetadata());

   auto *V2 = MetadataAsValue::get(Context, N2);
   EXPECT_EQ(V, V2);

   auto *V3 = MetadataAsValue::get(Context, N);
   EXPECT_TRUE(V3->getType()->isMetadataTy());
   EXPECT_NE(V, V3);
   EXPECT_EQ(N, V3->getMetadata());
 }

 TEST_F(MetadataAsValueTest, MDNodeConstant) {
   auto *C = ConstantInt::getTrue(Context);
   auto *MD = ConstantAsMetadata::get(C);
   Metadata *Ops[] = {MD};
   auto *N = MDNode::get(Context, Ops);

   auto *V = MetadataAsValue::get(Context, MD);
   EXPECT_TRUE(V->getType()->isMetadataTy());
   EXPECT_EQ(MD, V->getMetadata());

   auto *V2 = MetadataAsValue::get(Context, N);
   EXPECT_EQ(MD, V2->getMetadata());
   EXPECT_EQ(V, V2);
 }

 typedef MetadataTest ValueAsMetadataTest;

 TEST_F(ValueAsMetadataTest, UpdatesOnRAUW) {
   Type *Ty = Type::getInt1PtrTy(Context);
   std::unique_ptr<GlobalVariable> GV0(
       new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
   auto *MD = ValueAsMetadata::get(GV0.get());
   EXPECT_TRUE(MD->getValue() == GV0.get());
   ASSERT_TRUE(GV0->use_empty());

   std::unique_ptr<GlobalVariable> GV1(
       new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
   GV0->replaceAllUsesWith(GV1.get());
   EXPECT_TRUE(MD->getValue() == GV1.get());
 }

 typedef MetadataTest TrackingMDRefTest;

 TEST_F(TrackingMDRefTest, UpdatesOnRAUW) {
   Type *Ty = Type::getInt1PtrTy(Context);
   std::unique_ptr<GlobalVariable> GV0(
       new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
   TypedTrackingMDRef<ValueAsMetadata> MD(ValueAsMetadata::get(GV0.get()));
   EXPECT_TRUE(MD->getValue() == GV0.get());
   ASSERT_TRUE(GV0->use_empty());

   std::unique_ptr<GlobalVariable> GV1(
       new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
   GV0->replaceAllUsesWith(GV1.get());
   EXPECT_TRUE(MD->getValue() == GV1.get());

   // Reset it, so we don't inadvertently test deletion.
   MD.reset();
 }

 TEST_F(TrackingMDRefTest, UpdatesOnDeletion) {
   Type *Ty = Type::getInt1PtrTy(Context);
   std::unique_ptr<GlobalVariable> GV(
       new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
   TypedTrackingMDRef<ValueAsMetadata> MD(ValueAsMetadata::get(GV.get()));
   EXPECT_TRUE(MD->getValue() == GV.get());
   ASSERT_TRUE(GV->use_empty());

   GV.reset();
   EXPECT_TRUE(!MD);
 }

 TEST(NamedMDNodeTest, Search) {
   LLVMContext Context;
   ConstantAsMetadata *C =
       ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), 1));
   ConstantAsMetadata *C2 =
       ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), 2));

   Metadata *const V = C;
   Metadata *const V2 = C2;
   MDNode *n = MDNode::get(Context, V);
   MDNode *n2 = MDNode::get(Context, V2);

   Module M("MyModule", Context);
   const char *Name = "llvm.NMD1";
   NamedMDNode *NMD = M.getOrInsertNamedMetadata(Name);
   NMD->addOperand(n);
   NMD->addOperand(n2);

   std::string Str;
   raw_string_ostream oss(Str);
   NMD->print(oss);
   EXPECT_STREQ("!llvm.NMD1 = !{!0, !1}\n",
                oss.str().c_str());
 }
 }
	//===- llvm/unittest/IR/Metadata.cpp - Metadata unit tests ----------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/IR/Metadata.h"
	#include "llvm/IR/Constants.h"
	#include "llvm/IR/Instructions.h"
	#include "llvm/IR/LLVMContext.h"
	#include "llvm/IR/Module.h"
	#include "llvm/IR/Type.h"
	#include "llvm/Support/raw_ostream.h"
	#include "gtest/gtest.h"
	using namespace llvm;

	namespace {

	class MetadataTest : public testing::Test {
	protected:
	LLVMContext Context;
	MDNode *getNode() { return MDNode::get(Context, None); }
	MDNode getNode(Metadata MD) { return MDNode::get(Context, MD); }
	MDNode getNode(Metadata MD1, Metadata *MD2) {
	Metadata *MDs[] = {MD1, MD2};
	return MDNode::get(Context, MDs);
	}
	};
	typedef MetadataTest MDStringTest;

	// Test that construction of MDString with different value produces different
	// MDString objects, even with the same string pointer and nulls in the string.
	TEST_F(MDStringTest, CreateDifferent) {
	char x[3] = { 'f', 0, 'A' };
	MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
	x[2] = 'B';
	MDString *s2 = MDString::get(Context, StringRef(&x[0], 3));
	EXPECT_NE(s1, s2);
	}

	// Test that creation of MDStrings with the same string contents produces the
	// same MDString object, even with different pointers.
	TEST_F(MDStringTest, CreateSame) {
	char x[4] = { 'a', 'b', 'c', 'X' };
	char y[4] = { 'a', 'b', 'c', 'Y' };

	MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
	MDString *s2 = MDString::get(Context, StringRef(&y[0], 3));
	EXPECT_EQ(s1, s2);
	}

	// Test that MDString prints out the string we fed it.
	TEST_F(MDStringTest, PrintingSimple) {
	char *str = new char[13];
	strncpy(str, "testing 1 2 3", 13);
	MDString *s = MDString::get(Context, StringRef(str, 13));
	strncpy(str, "aaaaaaaaaaaaa", 13);
	delete[] str;

	std::string Str;
	raw_string_ostream oss(Str);
	s->print(oss);
	EXPECT_STREQ("!\"testing 1 2 3\"", oss.str().c_str());
	}

	// Test printing of MDString with non-printable characters.
	TEST_F(MDStringTest, PrintingComplex) {
	char str[5] = {0, '\n', '"', '\\', (char)-1};
	MDString *s = MDString::get(Context, StringRef(str+0, 5));
	std::string Str;
	raw_string_ostream oss(Str);
	s->print(oss);
	EXPECT_STREQ("!\"\\00\\0A\\22\\5C\\FF\"", oss.str().c_str());
	}

	typedef MetadataTest MDNodeTest;

	// Test the two constructors, and containing other Constants.
	TEST_F(MDNodeTest, Simple) {
	char x[3] = { 'a', 'b', 'c' };
	char y[3] = { '1', '2', '3' };

	MDString *s1 = MDString::get(Context, StringRef(&x[0], 3));
	MDString *s2 = MDString::get(Context, StringRef(&y[0], 3));
	ConstantAsMetadata *CI = ConstantAsMetadata::get(
	ConstantInt::get(getGlobalContext(), APInt(8, 0)));

	std::vector<Metadata *> V;
	V.push_back(s1);
	V.push_back(CI);
	V.push_back(s2);

	MDNode *n1 = MDNode::get(Context, V);
	Metadata *const c1 = n1;
	MDNode *n2 = MDNode::get(Context, c1);
	Metadata *const c2 = n2;
	MDNode *n3 = MDNode::get(Context, V);
	MDNode *n4 = MDNode::getIfExists(Context, V);
	MDNode *n5 = MDNode::getIfExists(Context, c1);
	MDNode *n6 = MDNode::getIfExists(Context, c2);
	EXPECT_NE(n1, n2);
	EXPECT_EQ(n1, n3);
	EXPECT_EQ(n4, n1);
	EXPECT_EQ(n5, n2);
	EXPECT_EQ(n6, (Metadata *)nullptr);

	EXPECT_EQ(3u, n1->getNumOperands());
	EXPECT_EQ(s1, n1->getOperand(0));
	EXPECT_EQ(CI, n1->getOperand(1));
	EXPECT_EQ(s2, n1->getOperand(2));

	EXPECT_EQ(1u, n2->getNumOperands());
	EXPECT_EQ(n1, n2->getOperand(0));
	}

	TEST_F(MDNodeTest, Delete) {
	Constant *C = ConstantInt::get(Type::getInt32Ty(getGlobalContext()), 1);
	Instruction *I = new BitCastInst(C, Type::getInt32Ty(getGlobalContext()));

	Metadata *const V = LocalAsMetadata::get(I);
	MDNode *n = MDNode::get(Context, V);
	TrackingMDRef wvh(n);

	EXPECT_EQ(n, wvh);

	delete I;
	}

	TEST_F(MDNodeTest, SelfReference) {
	// !0 = !{!0}
	// !1 = !{!0}
	{
	MDNode *Temp = MDNode::getTemporary(Context, None);
	Metadata *Args[] = {Temp};
	MDNode *Self = MDNode::get(Context, Args);
	Self->replaceOperandWith(0, Self);
	MDNode::deleteTemporary(Temp);
	ASSERT_EQ(Self, Self->getOperand(0));

	// Self-references should be distinct, so MDNode::get() should grab a
	// uniqued node that references Self, not Self.
	Args[0] = Self;
	MDNode *Ref1 = MDNode::get(Context, Args);
	MDNode *Ref2 = MDNode::get(Context, Args);
	EXPECT_NE(Self, Ref1);
	EXPECT_EQ(Ref1, Ref2);
	}

	// !0 = !{!0, !{}}
	// !1 = !{!0, !{}}
	{
	MDNode *Temp = MDNode::getTemporary(Context, None);
	Metadata *Args[] = {Temp, MDNode::get(Context, None)};
	MDNode *Self = MDNode::get(Context, Args);
	Self->replaceOperandWith(0, Self);
	MDNode::deleteTemporary(Temp);
	ASSERT_EQ(Self, Self->getOperand(0));

	// Self-references should be distinct, so MDNode::get() should grab a
	// uniqued node that references Self, not Self itself.
	Args[0] = Self;
	MDNode *Ref1 = MDNode::get(Context, Args);
	MDNode *Ref2 = MDNode::get(Context, Args);
	EXPECT_NE(Self, Ref1);
	EXPECT_EQ(Ref1, Ref2);
	}
	}

	TEST_F(MDNodeTest, Print) {
	Constant *C = ConstantInt::get(Type::getInt32Ty(Context), 7);
	MDString *S = MDString::get(Context, "foo");
	MDNode *N0 = getNode();
	MDNode *N1 = getNode(N0);
	MDNode *N2 = getNode(N0, N1);

	Metadata *Args[] = {ConstantAsMetadata::get(C), S, nullptr, N0, N1, N2};
	MDNode *N = MDNode::get(Context, Args);

	std::string Expected;
	{
	raw_string_ostream OS(Expected);
	OS << "!{";
	C->printAsOperand(OS);
	OS << ", ";
	S->printAsOperand(OS);
	OS << ", null";
	MDNode *Nodes[] = {N0, N1, N2};
	for (auto *Node : Nodes)
	OS << ", <" << (void *)Node << ">";
	OS << "}\n";
	}

	std::string Actual;
	{
	raw_string_ostream OS(Actual);
	N->print(OS);
	}

	EXPECT_EQ(Expected, Actual);
	}

	TEST_F(MDNodeTest, NullOperand) {
	// metadata !{}
	MDNode *Empty = MDNode::get(Context, None);

	// metadata !{metadata !{}}
	Metadata *Ops[] = {Empty};
	MDNode *N = MDNode::get(Context, Ops);
	ASSERT_EQ(Empty, N->getOperand(0));

	// metadata !{metadata !{}} => metadata !{null}
	N->replaceOperandWith(0, nullptr);
	ASSERT_EQ(nullptr, N->getOperand(0));

	// metadata !{null}
	Ops[0] = nullptr;
	MDNode *NullOp = MDNode::get(Context, Ops);
	ASSERT_EQ(nullptr, NullOp->getOperand(0));
	EXPECT_EQ(N, NullOp);
	}

	typedef MetadataTest MetadataAsValueTest;

	TEST_F(MetadataAsValueTest, MDNode) {
	MDNode *N = MDNode::get(Context, None);
	auto *V = MetadataAsValue::get(Context, N);
	EXPECT_TRUE(V->getType()->isMetadataTy());
	EXPECT_EQ(N, V->getMetadata());

	auto *V2 = MetadataAsValue::get(Context, N);
	EXPECT_EQ(V, V2);
	}

	TEST_F(MetadataAsValueTest, MDNodeMDNode) {
	MDNode *N = MDNode::get(Context, None);
	Metadata *Ops[] = {N};
	MDNode *N2 = MDNode::get(Context, Ops);
	auto *V = MetadataAsValue::get(Context, N2);
	EXPECT_TRUE(V->getType()->isMetadataTy());
	EXPECT_EQ(N2, V->getMetadata());

	auto *V2 = MetadataAsValue::get(Context, N2);
	EXPECT_EQ(V, V2);

	auto *V3 = MetadataAsValue::get(Context, N);
	EXPECT_TRUE(V3->getType()->isMetadataTy());
	EXPECT_NE(V, V3);
	EXPECT_EQ(N, V3->getMetadata());
	}

	TEST_F(MetadataAsValueTest, MDNodeConstant) {
	auto *C = ConstantInt::getTrue(Context);
	auto *MD = ConstantAsMetadata::get(C);
	Metadata *Ops[] = {MD};
	auto *N = MDNode::get(Context, Ops);

	auto *V = MetadataAsValue::get(Context, MD);
	EXPECT_TRUE(V->getType()->isMetadataTy());
	EXPECT_EQ(MD, V->getMetadata());

	auto *V2 = MetadataAsValue::get(Context, N);
	EXPECT_EQ(MD, V2->getMetadata());
	EXPECT_EQ(V, V2);
	}

	typedef MetadataTest ValueAsMetadataTest;

	TEST_F(ValueAsMetadataTest, UpdatesOnRAUW) {
	Type *Ty = Type::getInt1PtrTy(Context);
	std::unique_ptr<GlobalVariable> GV0(
	new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
	auto *MD = ValueAsMetadata::get(GV0.get());
	EXPECT_TRUE(MD->getValue() == GV0.get());
	ASSERT_TRUE(GV0->use_empty());

	std::unique_ptr<GlobalVariable> GV1(
	new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
	GV0->replaceAllUsesWith(GV1.get());
	EXPECT_TRUE(MD->getValue() == GV1.get());
	}

	typedef MetadataTest TrackingMDRefTest;

	TEST_F(TrackingMDRefTest, UpdatesOnRAUW) {
	Type *Ty = Type::getInt1PtrTy(Context);
	std::unique_ptr<GlobalVariable> GV0(
	new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
	TypedTrackingMDRef<ValueAsMetadata> MD(ValueAsMetadata::get(GV0.get()));
	EXPECT_TRUE(MD->getValue() == GV0.get());
	ASSERT_TRUE(GV0->use_empty());

	std::unique_ptr<GlobalVariable> GV1(
	new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
	GV0->replaceAllUsesWith(GV1.get());
	EXPECT_TRUE(MD->getValue() == GV1.get());

	// Reset it, so we don't inadvertently test deletion.
	MD.reset();
	}

	TEST_F(TrackingMDRefTest, UpdatesOnDeletion) {
	Type *Ty = Type::getInt1PtrTy(Context);
	std::unique_ptr<GlobalVariable> GV(
	new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage));
	TypedTrackingMDRef<ValueAsMetadata> MD(ValueAsMetadata::get(GV.get()));
	EXPECT_TRUE(MD->getValue() == GV.get());
	ASSERT_TRUE(GV->use_empty());

	GV.reset();
	EXPECT_TRUE(!MD);
	}

	TEST(NamedMDNodeTest, Search) {
	LLVMContext Context;
	ConstantAsMetadata *C =
	ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), 1));
	ConstantAsMetadata *C2 =
	ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), 2));

	Metadata *const V = C;
	Metadata *const V2 = C2;
	MDNode *n = MDNode::get(Context, V);
	MDNode *n2 = MDNode::get(Context, V2);

	Module M("MyModule", Context);
	const char *Name = "llvm.NMD1";
	NamedMDNode *NMD = M.getOrInsertNamedMetadata(Name);
	NMD->addOperand(n);
	NMD->addOperand(n2);

	std::string Str;
	raw_string_ostream oss(Str);
	NMD->print(oss);
	EXPECT_STREQ("!llvm.NMD1 = !{!0, !1}\n",
	oss.str().c_str());
	}
	}