clang/unittests/Analysis/LifetimeSafetyTest.cpp - llvm-project - Git at Google

 //===- LifetimeSafetyTest.cpp - Lifetime Safety Tests -*---------- C++-*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Analysis/Analyses/LifetimeSafety.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Testing/TestAST.h"
 #include "llvm/ADT/StringMap.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <optional>
 #include <vector>

 namespace clang::lifetimes::internal {
 namespace {

 using namespace ast_matchers;
 using ::testing::UnorderedElementsAreArray;

 // A helper class to run the full lifetime analysis on a piece of code
 // and provide an interface for querying the results.
 class LifetimeTestRunner {
 public:
   LifetimeTestRunner(llvm::StringRef Code) {
     std::string FullCode = R"(
       #define POINT(name) void("__lifetime_test_point_" #name)
       struct MyObj { ~MyObj() {} int i; };
     )";
     FullCode += Code.str();

     TestAST = std::make_unique<clang::TestAST>(FullCode);
     ASTCtx = &TestAST->context();

     // Find the target function using AST matchers.
     auto MatchResult =
         match(functionDecl(hasName("target")).bind("target"), *ASTCtx);
     auto *FD = selectFirst<FunctionDecl>("target", MatchResult);
     if (!FD) {
       ADD_FAILURE() << "Test case must have a function named 'target'";
       return;
     }
     AnalysisCtx = std::make_unique<AnalysisDeclContext>(nullptr, FD);
     AnalysisCtx->getCFGBuildOptions().setAllAlwaysAdd();

     // Run the main analysis.
     Analysis = std::make_unique<LifetimeSafetyAnalysis>(*AnalysisCtx);
     Analysis->run();

     AnnotationToPointMap = Analysis->getTestPoints();
   }

   LifetimeSafetyAnalysis &getAnalysis() { return *Analysis; }
   ASTContext &getASTContext() { return *ASTCtx; }

   ProgramPoint getProgramPoint(llvm::StringRef Annotation) {
     auto It = AnnotationToPointMap.find(Annotation);
     if (It == AnnotationToPointMap.end()) {
       ADD_FAILURE() << "Annotation '" << Annotation << "' not found.";
       return nullptr;
     }
     return It->second;
   }

 private:
   std::unique_ptr<TestAST> TestAST;
   ASTContext *ASTCtx = nullptr;
   std::unique_ptr<AnalysisDeclContext> AnalysisCtx;
   std::unique_ptr<LifetimeSafetyAnalysis> Analysis;
   llvm::StringMap<ProgramPoint> AnnotationToPointMap;
 };

 // A convenience wrapper that uses the LifetimeSafetyAnalysis public API.
 class LifetimeTestHelper {
 public:
   LifetimeTestHelper(LifetimeTestRunner &Runner)
       : Runner(Runner), Analysis(Runner.getAnalysis()) {}

   std::optional<OriginID> getOriginForDecl(llvm::StringRef VarName) {
     auto *VD = findDecl<ValueDecl>(VarName);
     if (!VD)
       return std::nullopt;
     auto OID = Analysis.getOriginIDForDecl(VD);
     if (!OID)
       ADD_FAILURE() << "Origin for '" << VarName << "' not found.";
     return OID;
   }

   std::optional<LoanID> getLoanForVar(llvm::StringRef VarName) {
     auto *VD = findDecl<VarDecl>(VarName);
     if (!VD)
       return std::nullopt;
     std::vector<LoanID> LID = Analysis.getLoanIDForVar(VD);
     if (LID.empty()) {
       ADD_FAILURE() << "Loan for '" << VarName << "' not found.";
       return std::nullopt;
     }
     // TODO: Support retrieving more than one loans to a var.
     if (LID.size() > 1) {
       ADD_FAILURE() << "More than 1 loans found for '" << VarName;
       return std::nullopt;
     }
     return LID[0];
   }

   std::optional<LoanSet> getLoansAtPoint(OriginID OID,
                                          llvm::StringRef Annotation) {
     ProgramPoint PP = Runner.getProgramPoint(Annotation);
     if (!PP)
       return std::nullopt;
     return Analysis.getLoansAtPoint(OID, PP);
   }

 private:
   template <typename DeclT> DeclT *findDecl(llvm::StringRef Name) {
     auto &Ctx = Runner.getASTContext();
     auto Results = match(valueDecl(hasName(Name)).bind("v"), Ctx);
     if (Results.empty()) {
       ADD_FAILURE() << "Declaration '" << Name << "' not found in AST.";
       return nullptr;
     }
     return const_cast<DeclT *>(selectFirst<DeclT>("v", Results));
   }

   LifetimeTestRunner &Runner;
   LifetimeSafetyAnalysis &Analysis;
 };

 // ========================================================================= //
 //                         GTest Matchers & Fixture
 // ========================================================================= //

 // It holds the name of the origin variable and a reference to the helper.
 class OriginInfo {
 public:
   OriginInfo(llvm::StringRef OriginVar, LifetimeTestHelper &Helper)
       : OriginVar(OriginVar), Helper(Helper) {}
   llvm::StringRef OriginVar;
   LifetimeTestHelper &Helper;
 };

 /// Matcher to verify the set of loans held by an origin at a specific
 /// program point.
 ///
 /// This matcher is intended to be used with an \c OriginInfo object.
 ///
 /// \param LoanVars A vector of strings, where each string is the name of a
 /// variable expected to be the source of a loan.
 /// \param Annotation A string identifying the program point (created with
 /// POINT()) where the check should be performed.
 MATCHER_P2(HasLoansToImpl, LoanVars, Annotation, "") {
   const OriginInfo &Info = arg;
   std::optional<OriginID> OIDOpt = Info.Helper.getOriginForDecl(Info.OriginVar);
   if (!OIDOpt) {
     *result_listener << "could not find origin for '" << Info.OriginVar.str()
                      << "'";
     return false;
   }

   std::optional<LoanSet> ActualLoansSetOpt =
       Info.Helper.getLoansAtPoint(*OIDOpt, Annotation);
   if (!ActualLoansSetOpt) {
     *result_listener << "could not get a valid loan set at point '"
                      << Annotation << "'";
     return false;
   }
   std::vector<LoanID> ActualLoans(ActualLoansSetOpt->begin(),
                                   ActualLoansSetOpt->end());

   std::vector<LoanID> ExpectedLoans;
   for (const auto &LoanVar : LoanVars) {
     std::optional<LoanID> ExpectedLIDOpt = Info.Helper.getLoanForVar(LoanVar);
     if (!ExpectedLIDOpt) {
       *result_listener << "could not find loan for var '" << LoanVar << "'";
       return false;
     }
     ExpectedLoans.push_back(*ExpectedLIDOpt);
   }

   return ExplainMatchResult(UnorderedElementsAreArray(ExpectedLoans),
                             ActualLoans, result_listener);
 }

 // Base test fixture to manage the runner and helper.
 class LifetimeAnalysisTest : public ::testing::Test {
 protected:
   void SetupTest(llvm::StringRef Code) {
     Runner = std::make_unique<LifetimeTestRunner>(Code);
     Helper = std::make_unique<LifetimeTestHelper>(*Runner);
   }

   OriginInfo Origin(llvm::StringRef OriginVar) {
     return OriginInfo(OriginVar, *Helper);
   }

   // Factory function that hides the std::vector creation.
   auto HasLoansTo(std::initializer_list<std::string> LoanVars,
                   const char *Annotation) {
     return HasLoansToImpl(std::vector<std::string>(LoanVars), Annotation);
   }

   std::unique_ptr<LifetimeTestRunner> Runner;
   std::unique_ptr<LifetimeTestHelper> Helper;
 };

 // ========================================================================= //
 //                                 TESTS
 // ========================================================================= //

 TEST_F(LifetimeAnalysisTest, SimpleLoanAndOrigin) {
   SetupTest(R"(
     void target() {
       int x;
       int* p = &x;
       POINT(p1);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"x"}, "p1"));
 }

 TEST_F(LifetimeAnalysisTest, OverwriteOrigin) {
   SetupTest(R"(
     void target() {
       MyObj s1, s2;

       MyObj* p = &s1;
       POINT(after_s1);

       p = &s2;
       POINT(after_s2);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "after_s1"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "after_s2"));
 }

 TEST_F(LifetimeAnalysisTest, ConditionalLoan) {
   SetupTest(R"(
     void target(bool cond) {
       int a, b;
       int *p = nullptr;
       if (cond) {
         p = &a;
         POINT(after_then);
       } else {
         p = &b;
         POINT(after_else);
       }
       POINT(after_if);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"a"}, "after_then"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"b"}, "after_else"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"a", "b"}, "after_if"));
 }

 TEST_F(LifetimeAnalysisTest, PointerChain) {
   SetupTest(R"(
     void target() {
       MyObj y;
       MyObj* ptr1 = &y;
       POINT(p1);

       MyObj* ptr2 = ptr1;
       POINT(p2);

       ptr2 = ptr1;
       POINT(p3);

       ptr2 = ptr2; // Self assignment
       POINT(p4);
     }
   )");
   EXPECT_THAT(Origin("ptr1"), HasLoansTo({"y"}, "p1"));
   EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p2"));
   EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p3"));
   EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p4"));
 }

 TEST_F(LifetimeAnalysisTest, ReassignToNull) {
   SetupTest(R"(
     void target() {
       MyObj s1;
       MyObj* p = &s1;
       POINT(before_null);
       p = nullptr;
       POINT(after_null);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_null"));
   // After assigning to null, the origin for `p` should have no loans.
   EXPECT_THAT(Origin("p"), HasLoansTo({}, "after_null"));
 }

 TEST_F(LifetimeAnalysisTest, ReassignInIf) {
   SetupTest(R"(
     void target(bool condition) {
       MyObj s1, s2;
       MyObj* p = &s1;
       POINT(before_if);
       if (condition) {
         p = &s2;
         POINT(after_reassign);
       }
       POINT(after_if);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_if"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "after_reassign"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2"}, "after_if"));
 }

 TEST_F(LifetimeAnalysisTest, AssignInSwitch) {
   SetupTest(R"(
     void target(int mode) {
       MyObj s1, s2, s3;
       MyObj* p = nullptr;
       switch (mode) {
         case 1:
           p = &s1;
           POINT(case1);
           break;
         case 2:
           p = &s2;
           POINT(case2);
           break;
         default:
           p = &s3;
           POINT(case3);
           break;
       }
       POINT(after_switch);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "case1"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "case2"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s3"}, "case3"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2", "s3"}, "after_switch"));
 }

 TEST_F(LifetimeAnalysisTest, LoanInLoop) {
   SetupTest(R"(
     void target(bool condition) {
       MyObj* p = nullptr;
       while (condition) {
         MyObj inner;
         p = &inner;
         POINT(in_loop);
       }
       POINT(after_loop);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "in_loop"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "after_loop"));
 }

 TEST_F(LifetimeAnalysisTest, LoopWithBreak) {
   SetupTest(R"(
     void target(int count) {
       MyObj s1;
       MyObj s2;
       MyObj* p = &s1;
       POINT(before_loop);
       for (int i = 0; i < count; ++i) {
         if (i == 5) {
           p = &s2;
           POINT(inside_if);
           break;
         }
         POINT(after_if);
       }
       POINT(after_loop);
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_loop"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "inside_if"));
   // At the join point after if, s2 cannot make it to p without the if.
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "after_if"));
   // At the join point after the loop, p could hold a loan to s1 (if the loop
   // completed normally) or to s2 (if the loop was broken).
   EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2"}, "after_loop"));
 }

 TEST_F(LifetimeAnalysisTest, PointersInACycle) {
   SetupTest(R"(
     void target(bool condition) {
       MyObj v1, v2, v3;
       MyObj *p1 = &v1, *p2 = &v2, *p3 = &v3;

       POINT(before_while);
       while (condition) {
         MyObj* temp = p1;
         p1 = p2;
         p2 = p3;
         p3 = temp;
       }
       POINT(after_loop);
     }
   )");
   EXPECT_THAT(Origin("p1"), HasLoansTo({"v1"}, "before_while"));
   EXPECT_THAT(Origin("p2"), HasLoansTo({"v2"}, "before_while"));
   EXPECT_THAT(Origin("p3"), HasLoansTo({"v3"}, "before_while"));

   // At the fixed point after the loop, all pointers could point to any of
   // the three variables.
   EXPECT_THAT(Origin("p1"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
   EXPECT_THAT(Origin("p2"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
   EXPECT_THAT(Origin("p3"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
   EXPECT_THAT(Origin("temp"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
 }

 TEST_F(LifetimeAnalysisTest, NestedScopes) {
   SetupTest(R"(
     void target() {
       MyObj* p = nullptr;
       {
         MyObj outer;
         p = &outer;
         POINT(before_inner_scope);
         {
           MyObj inner;
           p = &inner;
           POINT(inside_inner_scope);
         } // inner expires
         POINT(after_inner_scope);
       } // outer expires
     }
   )");
   EXPECT_THAT(Origin("p"), HasLoansTo({"outer"}, "before_inner_scope"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "inside_inner_scope"));
   EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "after_inner_scope"));
 }

 } // anonymous namespace
 } // namespace clang::lifetimes::internal
	//===- LifetimeSafetyTest.cpp - Lifetime Safety Tests ----------- C++--===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Analysis/Analyses/LifetimeSafety.h"
	#include "clang/ASTMatchers/ASTMatchFinder.h"
	#include "clang/ASTMatchers/ASTMatchers.h"
	#include "clang/Testing/TestAST.h"
	#include "llvm/ADT/StringMap.h"
	#include "gmock/gmock.h"
	#include "gtest/gtest.h"
	#include <optional>
	#include <vector>

	namespace clang::lifetimes::internal {
	namespace {

	using namespace ast_matchers;
	using ::testing::UnorderedElementsAreArray;

	// A helper class to run the full lifetime analysis on a piece of code
	// and provide an interface for querying the results.
	class LifetimeTestRunner {
	public:
	LifetimeTestRunner(llvm::StringRef Code) {
	std::string FullCode = R"(
	#define POINT(name) void("__lifetime_test_point_" #name)
	struct MyObj { ~MyObj() {} int i; };
	)";
	FullCode += Code.str();

	TestAST = std::make_unique<clang::TestAST>(FullCode);
	ASTCtx = &TestAST->context();

	// Find the target function using AST matchers.
	auto MatchResult =
	match(functionDecl(hasName("target")).bind("target"), *ASTCtx);
	auto *FD = selectFirst<FunctionDecl>("target", MatchResult);
	if (!FD) {
	ADD_FAILURE() << "Test case must have a function named 'target'";
	return;
	}
	AnalysisCtx = std::make_unique<AnalysisDeclContext>(nullptr, FD);
	AnalysisCtx->getCFGBuildOptions().setAllAlwaysAdd();

	// Run the main analysis.
	Analysis = std::make_unique<LifetimeSafetyAnalysis>(*AnalysisCtx);
	Analysis->run();

	AnnotationToPointMap = Analysis->getTestPoints();
	}

	LifetimeSafetyAnalysis &getAnalysis() { return *Analysis; }
	ASTContext &getASTContext() { return *ASTCtx; }

	ProgramPoint getProgramPoint(llvm::StringRef Annotation) {
	auto It = AnnotationToPointMap.find(Annotation);
	if (It == AnnotationToPointMap.end()) {
	ADD_FAILURE() << "Annotation '" << Annotation << "' not found.";
	return nullptr;
	}
	return It->second;
	}

	private:
	std::unique_ptr<TestAST> TestAST;
	ASTContext *ASTCtx = nullptr;
	std::unique_ptr<AnalysisDeclContext> AnalysisCtx;
	std::unique_ptr<LifetimeSafetyAnalysis> Analysis;
	llvm::StringMap<ProgramPoint> AnnotationToPointMap;
	};

	// A convenience wrapper that uses the LifetimeSafetyAnalysis public API.
	class LifetimeTestHelper {
	public:
	LifetimeTestHelper(LifetimeTestRunner &Runner)
	: Runner(Runner), Analysis(Runner.getAnalysis()) {}

	std::optional<OriginID> getOriginForDecl(llvm::StringRef VarName) {
	auto *VD = findDecl<ValueDecl>(VarName);
	if (!VD)
	return std::nullopt;
	auto OID = Analysis.getOriginIDForDecl(VD);
	if (!OID)
	ADD_FAILURE() << "Origin for '" << VarName << "' not found.";
	return OID;
	}

	std::optional<LoanID> getLoanForVar(llvm::StringRef VarName) {
	auto *VD = findDecl<VarDecl>(VarName);
	if (!VD)
	return std::nullopt;
	std::vector<LoanID> LID = Analysis.getLoanIDForVar(VD);
	if (LID.empty()) {
	ADD_FAILURE() << "Loan for '" << VarName << "' not found.";
	return std::nullopt;
	}
	// TODO: Support retrieving more than one loans to a var.
	if (LID.size() > 1) {
	ADD_FAILURE() << "More than 1 loans found for '" << VarName;
	return std::nullopt;
	}
	return LID[0];
	}

	std::optional<LoanSet> getLoansAtPoint(OriginID OID,
	llvm::StringRef Annotation) {
	ProgramPoint PP = Runner.getProgramPoint(Annotation);
	if (!PP)
	return std::nullopt;
	return Analysis.getLoansAtPoint(OID, PP);
	}

	private:
	template <typename DeclT> DeclT *findDecl(llvm::StringRef Name) {
	auto &Ctx = Runner.getASTContext();
	auto Results = match(valueDecl(hasName(Name)).bind("v"), Ctx);
	if (Results.empty()) {
	ADD_FAILURE() << "Declaration '" << Name << "' not found in AST.";
	return nullptr;
	}
	return const_cast<DeclT *>(selectFirst<DeclT>("v", Results));
	}

	LifetimeTestRunner &Runner;
	LifetimeSafetyAnalysis &Analysis;
	};

	// ========================================================================= //
	// GTest Matchers & Fixture
	// ========================================================================= //

	// It holds the name of the origin variable and a reference to the helper.
	class OriginInfo {
	public:
	OriginInfo(llvm::StringRef OriginVar, LifetimeTestHelper &Helper)
	: OriginVar(OriginVar), Helper(Helper) {}
	llvm::StringRef OriginVar;
	LifetimeTestHelper &Helper;
	};

	/// Matcher to verify the set of loans held by an origin at a specific
	/// program point.
	///
	/// This matcher is intended to be used with an \c OriginInfo object.
	///
	/// \param LoanVars A vector of strings, where each string is the name of a
	/// variable expected to be the source of a loan.
	/// \param Annotation A string identifying the program point (created with
	/// POINT()) where the check should be performed.
	MATCHER_P2(HasLoansToImpl, LoanVars, Annotation, "") {
	const OriginInfo &Info = arg;
	std::optional<OriginID> OIDOpt = Info.Helper.getOriginForDecl(Info.OriginVar);
	if (!OIDOpt) {
	*result_listener << "could not find origin for '" << Info.OriginVar.str()
	<< "'";
	return false;
	}

	std::optional<LoanSet> ActualLoansSetOpt =
	Info.Helper.getLoansAtPoint(*OIDOpt, Annotation);
	if (!ActualLoansSetOpt) {
	*result_listener << "could not get a valid loan set at point '"
	<< Annotation << "'";
	return false;
	}
	std::vector<LoanID> ActualLoans(ActualLoansSetOpt->begin(),
	ActualLoansSetOpt->end());

	std::vector<LoanID> ExpectedLoans;
	for (const auto &LoanVar : LoanVars) {
	std::optional<LoanID> ExpectedLIDOpt = Info.Helper.getLoanForVar(LoanVar);
	if (!ExpectedLIDOpt) {
	*result_listener << "could not find loan for var '" << LoanVar << "'";
	return false;
	}
	ExpectedLoans.push_back(*ExpectedLIDOpt);
	}

	return ExplainMatchResult(UnorderedElementsAreArray(ExpectedLoans),
	ActualLoans, result_listener);
	}

	// Base test fixture to manage the runner and helper.
	class LifetimeAnalysisTest : public ::testing::Test {
	protected:
	void SetupTest(llvm::StringRef Code) {
	Runner = std::make_unique<LifetimeTestRunner>(Code);
	Helper = std::make_unique<LifetimeTestHelper>(*Runner);
	}

	OriginInfo Origin(llvm::StringRef OriginVar) {
	return OriginInfo(OriginVar, *Helper);
	}

	// Factory function that hides the std::vector creation.
	auto HasLoansTo(std::initializer_list<std::string> LoanVars,
	const char *Annotation) {
	return HasLoansToImpl(std::vector<std::string>(LoanVars), Annotation);
	}

	std::unique_ptr<LifetimeTestRunner> Runner;
	std::unique_ptr<LifetimeTestHelper> Helper;
	};

	// ========================================================================= //
	// TESTS
	// ========================================================================= //

	TEST_F(LifetimeAnalysisTest, SimpleLoanAndOrigin) {
	SetupTest(R"(
	void target() {
	int x;
	int* p = &x;
	POINT(p1);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"x"}, "p1"));
	}

	TEST_F(LifetimeAnalysisTest, OverwriteOrigin) {
	SetupTest(R"(
	void target() {
	MyObj s1, s2;

	MyObj* p = &s1;
	POINT(after_s1);

	p = &s2;
	POINT(after_s2);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "after_s1"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "after_s2"));
	}

	TEST_F(LifetimeAnalysisTest, ConditionalLoan) {
	SetupTest(R"(
	void target(bool cond) {
	int a, b;
	int *p = nullptr;
	if (cond) {
	p = &a;
	POINT(after_then);
	} else {
	p = &b;
	POINT(after_else);
	}
	POINT(after_if);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"a"}, "after_then"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"b"}, "after_else"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"a", "b"}, "after_if"));
	}

	TEST_F(LifetimeAnalysisTest, PointerChain) {
	SetupTest(R"(
	void target() {
	MyObj y;
	MyObj* ptr1 = &y;
	POINT(p1);

	MyObj* ptr2 = ptr1;
	POINT(p2);

	ptr2 = ptr1;
	POINT(p3);

	ptr2 = ptr2; // Self assignment
	POINT(p4);
	}
	)");
	EXPECT_THAT(Origin("ptr1"), HasLoansTo({"y"}, "p1"));
	EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p2"));
	EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p3"));
	EXPECT_THAT(Origin("ptr2"), HasLoansTo({"y"}, "p4"));
	}

	TEST_F(LifetimeAnalysisTest, ReassignToNull) {
	SetupTest(R"(
	void target() {
	MyObj s1;
	MyObj* p = &s1;
	POINT(before_null);
	p = nullptr;
	POINT(after_null);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_null"));
	// After assigning to null, the origin for `p` should have no loans.
	EXPECT_THAT(Origin("p"), HasLoansTo({}, "after_null"));
	}

	TEST_F(LifetimeAnalysisTest, ReassignInIf) {
	SetupTest(R"(
	void target(bool condition) {
	MyObj s1, s2;
	MyObj* p = &s1;
	POINT(before_if);
	if (condition) {
	p = &s2;
	POINT(after_reassign);
	}
	POINT(after_if);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_if"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "after_reassign"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2"}, "after_if"));
	}

	TEST_F(LifetimeAnalysisTest, AssignInSwitch) {
	SetupTest(R"(
	void target(int mode) {
	MyObj s1, s2, s3;
	MyObj* p = nullptr;
	switch (mode) {
	case 1:
	p = &s1;
	POINT(case1);
	break;
	case 2:
	p = &s2;
	POINT(case2);
	break;
	default:
	p = &s3;
	POINT(case3);
	break;
	}
	POINT(after_switch);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "case1"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "case2"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s3"}, "case3"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2", "s3"}, "after_switch"));
	}

	TEST_F(LifetimeAnalysisTest, LoanInLoop) {
	SetupTest(R"(
	void target(bool condition) {
	MyObj* p = nullptr;
	while (condition) {
	MyObj inner;
	p = &inner;
	POINT(in_loop);
	}
	POINT(after_loop);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "in_loop"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "after_loop"));
	}

	TEST_F(LifetimeAnalysisTest, LoopWithBreak) {
	SetupTest(R"(
	void target(int count) {
	MyObj s1;
	MyObj s2;
	MyObj* p = &s1;
	POINT(before_loop);
	for (int i = 0; i < count; ++i) {
	if (i == 5) {
	p = &s2;
	POINT(inside_if);
	break;
	}
	POINT(after_if);
	}
	POINT(after_loop);
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "before_loop"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"s2"}, "inside_if"));
	// At the join point after if, s2 cannot make it to p without the if.
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1"}, "after_if"));
	// At the join point after the loop, p could hold a loan to s1 (if the loop
	// completed normally) or to s2 (if the loop was broken).
	EXPECT_THAT(Origin("p"), HasLoansTo({"s1", "s2"}, "after_loop"));
	}

	TEST_F(LifetimeAnalysisTest, PointersInACycle) {
	SetupTest(R"(
	void target(bool condition) {
	MyObj v1, v2, v3;
	MyObj p1 = &v1, p2 = &v2, *p3 = &v3;

	POINT(before_while);
	while (condition) {
	MyObj* temp = p1;
	p1 = p2;
	p2 = p3;
	p3 = temp;
	}
	POINT(after_loop);
	}
	)");
	EXPECT_THAT(Origin("p1"), HasLoansTo({"v1"}, "before_while"));
	EXPECT_THAT(Origin("p2"), HasLoansTo({"v2"}, "before_while"));
	EXPECT_THAT(Origin("p3"), HasLoansTo({"v3"}, "before_while"));

	// At the fixed point after the loop, all pointers could point to any of
	// the three variables.
	EXPECT_THAT(Origin("p1"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
	EXPECT_THAT(Origin("p2"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
	EXPECT_THAT(Origin("p3"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
	EXPECT_THAT(Origin("temp"), HasLoansTo({"v1", "v2", "v3"}, "after_loop"));
	}

	TEST_F(LifetimeAnalysisTest, NestedScopes) {
	SetupTest(R"(
	void target() {
	MyObj* p = nullptr;
	{
	MyObj outer;
	p = &outer;
	POINT(before_inner_scope);
	{
	MyObj inner;
	p = &inner;
	POINT(inside_inner_scope);
	} // inner expires
	POINT(after_inner_scope);
	} // outer expires
	}
	)");
	EXPECT_THAT(Origin("p"), HasLoansTo({"outer"}, "before_inner_scope"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "inside_inner_scope"));
	EXPECT_THAT(Origin("p"), HasLoansTo({"inner"}, "after_inner_scope"));
	}

	} // anonymous namespace
	} // namespace clang::lifetimes::internal