clang-tools-extra/clangd/unittests/PreambleTests.cpp - llvm-project - Git at Google

 //===--- PreambleTests.cpp --------------------------------------*- 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 "Annotations.h"
 #include "Compiler.h"
 #include "Headers.h"
 #include "Hover.h"
 #include "Preamble.h"
 #include "SourceCode.h"
 #include "TestFS.h"
 #include "TestTU.h"
 #include "XRefs.h"
 #include "clang/Format/Format.h"
 #include "clang/Frontend/PrecompiledPreamble.h"
 #include "clang/Lex/PreprocessorOptions.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <clang/Frontend/FrontendActions.h>
 #include <memory>
 #include <string>
 #include <vector>

 using testing::Contains;
 using testing::Field;
 using testing::Matcher;
 using testing::MatchesRegex;

 namespace clang {
 namespace clangd {
 namespace {

 MATCHER_P2(Distance, File, D, "") {
   return arg.first() == File && arg.second == D;
 }

 // Builds a preamble for BaselineContents, patches it for ModifiedContents and
 // returns the includes in the patch.
 IncludeStructure
 collectPatchedIncludes(llvm::StringRef ModifiedContents,
                        llvm::StringRef BaselineContents,
                        llvm::StringRef MainFileName = "main.cpp") {
   MockFS FS;
   auto TU = TestTU::withCode(BaselineContents);
   TU.Filename = MainFileName.str();
   // ms-compatibility changes meaning of #import, make sure it is turned off.
   TU.ExtraArgs = {"-fno-ms-compatibility"};
   auto BaselinePreamble = TU.preamble();
   // Create the patch.
   TU.Code = ModifiedContents.str();
   auto PI = TU.inputs(FS);
   auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename), PI,
                                            *BaselinePreamble);
   // Collect patch contents.
   IgnoreDiagnostics Diags;
   auto CI = buildCompilerInvocation(PI, Diags);
   PP.apply(*CI);
   // Run preprocessor over the modified contents with patched Invocation. We
   // provide a preamble and trim contents to ensure only the implicit header
   // introduced by the patch is parsed and nothing else.
   // We don't run PP directly over the patch cotents to test production
   // behaviour.
   auto Bounds = Lexer::ComputePreamble(ModifiedContents, *CI->getLangOpts());
   auto Clang =
       prepareCompilerInstance(std::move(CI), &BaselinePreamble->Preamble,
                               llvm::MemoryBuffer::getMemBufferCopy(
                                   ModifiedContents.slice(0, Bounds.Size).str()),
                               PI.TFS->view(PI.CompileCommand.Directory), Diags);
   PreprocessOnlyAction Action;
   if (!Action.BeginSourceFile(*Clang, Clang->getFrontendOpts().Inputs[0])) {
     ADD_FAILURE() << "failed begin source file";
     return {};
   }
   IncludeStructure Includes;
   Clang->getPreprocessor().addPPCallbacks(
       Includes.collect(Clang->getSourceManager()));
   if (llvm::Error Err = Action.Execute()) {
     ADD_FAILURE() << "failed to execute action: " << std::move(Err);
     return {};
   }
   Action.EndSourceFile();
   return Includes;
 }

 // Check preamble lexing logic by building an empty preamble and patching it
 // with all the contents.
 TEST(PreamblePatchTest, IncludeParsing) {
   // We expect any line with a point to show up in the patch.
   llvm::StringRef Cases[] = {
       // Only preamble
       R"cpp(^#include "a.h")cpp",
       // Both preamble and mainfile
       R"cpp(
         ^#include "a.h"
         garbage, finishes preamble
         #include "a.h")cpp",
       // Mixed directives
       R"cpp(
         ^#include "a.h"
         #pragma directive
         // some comments
         ^#include_next <a.h>
         #ifdef skipped
         ^#import "a.h"
         #endif)cpp",
       // Broken directives
       R"cpp(
         #include "a
         ^#include "a.h"
         #include <b
         ^#include <b.h>)cpp",
       // Directive is not part of preamble if it is not the token immediately
       // followed by the hash (#).
       R"cpp(
         ^#include "a.h"
         #/**/include <b.h>)cpp",
   };

   for (const auto &Case : Cases) {
     Annotations Test(Case);
     const auto Code = Test.code();
     SCOPED_TRACE(Code);

     auto Includes =
         collectPatchedIncludes(Code, /*BaselineContents=*/"").MainFileIncludes;
     auto Points = Test.points();
     ASSERT_EQ(Includes.size(), Points.size());
     for (size_t I = 0, E = Includes.size(); I != E; ++I)
       EXPECT_EQ(Includes[I].HashLine, Points[I].line);
   }
 }

 TEST(PreamblePatchTest, ContainsNewIncludes) {
   constexpr llvm::StringLiteral BaselineContents = R"cpp(
     #include <a.h>
     #include <b.h> // This will be removed
     #include <c.h>
   )cpp";
   constexpr llvm::StringLiteral ModifiedContents = R"cpp(
     #include <a.h>
     #include <c.h> // This has changed a line.
     #include <c.h> // This is a duplicate.
     #include <d.h> // This is newly introduced.
   )cpp";
   auto Includes = collectPatchedIncludes(ModifiedContents, BaselineContents)
                       .MainFileIncludes;
   EXPECT_THAT(Includes, ElementsAre(AllOf(Field(&Inclusion::Written, "<d.h>"),
                                           Field(&Inclusion::HashLine, 4))));
 }

 TEST(PreamblePatchTest, MainFileIsEscaped) {
   auto Includes = collectPatchedIncludes("#include <a.h>", "", "file\"name.cpp")
                       .MainFileIncludes;
   EXPECT_THAT(Includes, ElementsAre(AllOf(Field(&Inclusion::Written, "<a.h>"),
                                           Field(&Inclusion::HashLine, 0))));
 }

 TEST(PreamblePatchTest, PatchesPreambleIncludes) {
   MockFS FS;
   IgnoreDiagnostics Diags;
   auto TU = TestTU::withCode(R"cpp(
     #include "a.h"
     #include "c.h"
   )cpp");
   TU.AdditionalFiles["a.h"] = "#include \"b.h\"";
   TU.AdditionalFiles["b.h"] = "";
   TU.AdditionalFiles["c.h"] = "";
   auto PI = TU.inputs(FS);
   auto BaselinePreamble = buildPreamble(
       TU.Filename, *buildCompilerInvocation(PI, Diags), PI, true, nullptr);
   // We drop c.h from modified and add a new header. Since the latter is patched
   // we should only get a.h in preamble includes.
   TU.Code = R"cpp(
     #include "a.h"
     #include "b.h"
   )cpp";
   auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename), TU.inputs(FS),
                                            *BaselinePreamble);
   // Only a.h should exists in the preamble, as c.h has been dropped and b.h was
   // newly introduced.
   EXPECT_THAT(PP.preambleIncludes(),
               ElementsAre(AllOf(Field(&Inclusion::Written, "\"a.h\""),
                                 Field(&Inclusion::Resolved, testPath("a.h")))));
 }

 llvm::Optional<ParsedAST> createPatchedAST(llvm::StringRef Baseline,
                                            llvm::StringRef Modified) {
   auto BaselinePreamble = TestTU::withCode(Baseline).preamble();
   if (!BaselinePreamble) {
     ADD_FAILURE() << "Failed to build baseline preamble";
     return llvm::None;
   }

   IgnoreDiagnostics Diags;
   MockFS FS;
   auto TU = TestTU::withCode(Modified);
   auto CI = buildCompilerInvocation(TU.inputs(FS), Diags);
   if (!CI) {
     ADD_FAILURE() << "Failed to build compiler invocation";
     return llvm::None;
   }
   return ParsedAST::build(testPath(TU.Filename), TU.inputs(FS), std::move(CI),
                           {}, BaselinePreamble);
 }

 std::string getPreamblePatch(llvm::StringRef Baseline,
                              llvm::StringRef Modified) {
   auto BaselinePreamble = TestTU::withCode(Baseline).preamble();
   if (!BaselinePreamble) {
     ADD_FAILURE() << "Failed to build baseline preamble";
     return "";
   }
   MockFS FS;
   auto TU = TestTU::withCode(Modified);
   return PreamblePatch::createFullPatch(testPath("main.cpp"), TU.inputs(FS),
                                         *BaselinePreamble)
       .text()
       .str();
 }

 TEST(PreamblePatchTest, Define) {
   // BAR should be defined while parsing the AST.
   struct {
     const char *const Contents;
     const char *const ExpectedPatch;
   } Cases[] = {
       {
           R"cpp(
         #define BAR
         [[BAR]])cpp",
           R"cpp(#line 0 ".*main.cpp"
 #line 2
 #define         BAR
 )cpp",
       },
       // multiline macro
       {
           R"cpp(
         #define BAR \

         [[BAR]])cpp",
           R"cpp(#line 0 ".*main.cpp"
 #line 2
 #define         BAR
 )cpp",
       },
       // multiline macro
       {
           R"cpp(
         #define \
                 BAR
         [[BAR]])cpp",
           R"cpp(#line 0 ".*main.cpp"
 #line 3
 #define         BAR
 )cpp",
       },
   };

   for (const auto &Case : Cases) {
     SCOPED_TRACE(Case.Contents);
     Annotations Modified(Case.Contents);
     EXPECT_THAT(getPreamblePatch("", Modified.code()),
                 MatchesRegex(Case.ExpectedPatch));

     auto AST = createPatchedAST("", Modified.code());
     ASSERT_TRUE(AST);
     std::vector<Range> MacroRefRanges;
     for (auto &M : AST->getMacros().MacroRefs) {
       for (auto &O : M.getSecond())
         MacroRefRanges.push_back(O.Rng);
     }
     EXPECT_THAT(MacroRefRanges, Contains(Modified.range()));
   }
 }

 TEST(PreamblePatchTest, OrderingPreserved) {
   llvm::StringLiteral Baseline = "#define BAR(X) X";
   Annotations Modified(R"cpp(
     #define BAR(X, Y) X Y
     #define BAR(X) X
     [[BAR]](int y);
   )cpp");

   llvm::StringLiteral ExpectedPatch(R"cpp(#line 0 ".*main.cpp"
 #line 2
 #define     BAR\(X, Y\) X Y
 #line 3
 #define     BAR\(X\) X
 )cpp");
   EXPECT_THAT(getPreamblePatch(Baseline, Modified.code()),
               MatchesRegex(ExpectedPatch.str()));

   auto AST = createPatchedAST(Baseline, Modified.code());
   ASSERT_TRUE(AST);
 }

 TEST(PreamblePatchTest, LocateMacroAtWorks) {
   struct {
     const char *const Baseline;
     const char *const Modified;
   } Cases[] = {
       // Addition of new directive
       {
           "",
           R"cpp(
             #define $def^FOO
             $use^FOO)cpp",
       },
       // Available inside preamble section
       {
           "",
           R"cpp(
             #define $def^FOO
             #undef $use^FOO)cpp",
       },
       // Available after undef, as we don't patch those
       {
           "",
           R"cpp(
             #define $def^FOO
             #undef FOO
             $use^FOO)cpp",
       },
       // Identifier on a different line
       {
           "",
           R"cpp(
             #define \
               $def^FOO
             $use^FOO)cpp",
       },
       // In presence of comment tokens
       {
           "",
           R"cpp(
             #\
               define /* FOO */\
               /* FOO */ $def^FOO
             $use^FOO)cpp",
       },
       // Moved around
       {
           "#define FOO",
           R"cpp(
             #define BAR
             #define $def^FOO
             $use^FOO)cpp",
       },
   };
   for (const auto &Case : Cases) {
     SCOPED_TRACE(Case.Modified);
     llvm::Annotations Modified(Case.Modified);
     auto AST = createPatchedAST(Case.Baseline, Modified.code());
     ASSERT_TRUE(AST);

     const auto &SM = AST->getSourceManager();
     auto *MacroTok = AST->getTokens().spelledTokenAt(
         SM.getComposedLoc(SM.getMainFileID(), Modified.point("use")));
     ASSERT_TRUE(MacroTok);

     auto FoundMacro = locateMacroAt(*MacroTok, AST->getPreprocessor());
     ASSERT_TRUE(FoundMacro);
     EXPECT_THAT(FoundMacro->Name, "FOO");

     auto MacroLoc = FoundMacro->NameLoc;
     EXPECT_EQ(SM.getFileID(MacroLoc), SM.getMainFileID());
     EXPECT_EQ(SM.getFileOffset(MacroLoc), Modified.point("def"));
   }
 }

 TEST(PreamblePatchTest, LocateMacroAtDeletion) {
   {
     // We don't patch deleted define directives, make sure we don't crash.
     llvm::StringLiteral Baseline = "#define FOO";
     llvm::Annotations Modified("^FOO");

     auto AST = createPatchedAST(Baseline, Modified.code());
     ASSERT_TRUE(AST);

     const auto &SM = AST->getSourceManager();
     auto *MacroTok = AST->getTokens().spelledTokenAt(
         SM.getComposedLoc(SM.getMainFileID(), Modified.point()));
     ASSERT_TRUE(MacroTok);

     auto FoundMacro = locateMacroAt(*MacroTok, AST->getPreprocessor());
     ASSERT_TRUE(FoundMacro);
     EXPECT_THAT(FoundMacro->Name, "FOO");
     auto HI =
         getHover(*AST, offsetToPosition(Modified.code(), Modified.point()),
                  format::getLLVMStyle(), nullptr);
     ASSERT_TRUE(HI);
     EXPECT_THAT(HI->Definition, testing::IsEmpty());
   }

   {
     // Offset is valid, but underlying text is different.
     llvm::StringLiteral Baseline = "#define FOO";
     Annotations Modified(R"cpp(#define BAR
     ^FOO")cpp");

     auto AST = createPatchedAST(Baseline, Modified.code());
     ASSERT_TRUE(AST);

     auto HI = getHover(*AST, Modified.point(), format::getLLVMStyle(), nullptr);
     ASSERT_TRUE(HI);
     EXPECT_THAT(HI->Definition, "#define BAR");
   }
 }

 MATCHER_P(referenceRangeIs, R, "") { return arg.Loc.range == R; }

 TEST(PreamblePatchTest, RefsToMacros) {
   struct {
     const char *const Baseline;
     const char *const Modified;
   } Cases[] = {
       // Newly added
       {
           "",
           R"cpp(
             #define ^FOO
             ^[[FOO]])cpp",
       },
       // Moved around
       {
           "#define FOO",
           R"cpp(
             #define BAR
             #define ^FOO
             ^[[FOO]])cpp",
       },
       // Ref in preamble section
       {
           "",
           R"cpp(
             #define ^FOO
             #undef ^FOO)cpp",
       },
   };

   for (const auto &Case : Cases) {
     Annotations Modified(Case.Modified);
     auto AST = createPatchedAST("", Modified.code());
     ASSERT_TRUE(AST);

     const auto &SM = AST->getSourceManager();
     std::vector<Matcher<ReferencesResult::Reference>> ExpectedLocations;
     for (const auto &R : Modified.ranges())
       ExpectedLocations.push_back(referenceRangeIs(R));

     for (const auto &P : Modified.points()) {
       auto *MacroTok = AST->getTokens().spelledTokenAt(SM.getComposedLoc(
           SM.getMainFileID(),
           llvm::cantFail(positionToOffset(Modified.code(), P))));
       ASSERT_TRUE(MacroTok);
       EXPECT_THAT(findReferences(*AST, P, 0).References,
                   testing::ElementsAreArray(ExpectedLocations));
     }
   }
 }

 TEST(TranslatePreamblePatchLocation, Simple) {
   auto TU = TestTU::withHeaderCode(R"cpp(
     #line 3 "main.cpp"
     int foo();)cpp");
   // Presumed line/col needs to be valid in the main file.
   TU.Code = R"cpp(// line 1
     // line 2
     // line 3
     // line 4)cpp";
   TU.Filename = "main.cpp";
   TU.HeaderFilename = "__preamble_patch__.h";
   TU.ImplicitHeaderGuard = false;

   auto AST = TU.build();
   auto &SM = AST.getSourceManager();
   auto &ND = findDecl(AST, "foo");
   EXPECT_NE(SM.getFileID(ND.getLocation()), SM.getMainFileID());

   auto TranslatedLoc = translatePreamblePatchLocation(ND.getLocation(), SM);
   auto DecompLoc = SM.getDecomposedLoc(TranslatedLoc);
   EXPECT_EQ(DecompLoc.first, SM.getMainFileID());
   EXPECT_EQ(SM.getLineNumber(DecompLoc.first, DecompLoc.second), 3U);
 }

 TEST(PreamblePatch, ModifiedBounds) {
   struct {
     const char *const Baseline;
     const char *const Modified;
   } Cases[] = {
       // Size increased
       {
           "",
           R"cpp(
             #define FOO
             FOO)cpp",
       },
       // Stayed same
       {"#define FOO", "#define BAR"},
       // Got smaller
       {
           R"cpp(
             #define FOO
             #undef FOO)cpp",
           "#define FOO"},
   };

   for (const auto &Case : Cases) {
     auto TU = TestTU::withCode(Case.Baseline);
     auto BaselinePreamble = TU.preamble();
     ASSERT_TRUE(BaselinePreamble);

     Annotations Modified(Case.Modified);
     TU.Code = Modified.code().str();
     MockFS FS;
     auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename),
                                              TU.inputs(FS), *BaselinePreamble);

     IgnoreDiagnostics Diags;
     auto CI = buildCompilerInvocation(TU.inputs(FS), Diags);
     ASSERT_TRUE(CI);

     const auto ExpectedBounds =
         Lexer::ComputePreamble(Case.Modified, *CI->getLangOpts());
     EXPECT_EQ(PP.modifiedBounds().Size, ExpectedBounds.Size);
     EXPECT_EQ(PP.modifiedBounds().PreambleEndsAtStartOfLine,
               ExpectedBounds.PreambleEndsAtStartOfLine);
   }
 }

 TEST(PreamblePatch, DropsDiagnostics) {
   llvm::StringLiteral Code = "#define FOO\nx;/* error-ok */";
   // First check that this code generates diagnostics.
   EXPECT_THAT(*TestTU::withCode(Code).build().getDiagnostics(),
               testing::Not(testing::IsEmpty()));
   // Ensure they are dropeed when a patched preamble is used.
   EXPECT_FALSE(createPatchedAST("", Code)->getDiagnostics());
 }

 TEST(PreamblePatch, MacroLoc) {
   llvm::StringLiteral Baseline = "\n#define MACRO 12\nint num = MACRO;";
   llvm::StringLiteral Modified = " \n#define MACRO 12\nint num = MACRO;";
   auto AST = createPatchedAST(Baseline, Modified);
   ASSERT_TRUE(AST);
 }

 TEST(PreamblePatch, NoopWhenNotRequested) {
   llvm::StringLiteral Baseline = "#define M\nint num = M;";
   llvm::StringLiteral Modified = "#define M\n#include <foo.h>\nint num = M;";
   auto TU = TestTU::withCode(Baseline);
   auto BaselinePreamble = TU.preamble();
   ASSERT_TRUE(BaselinePreamble);

   TU.Code = Modified.str();
   MockFS FS;
   auto PP = PreamblePatch::createMacroPatch(testPath(TU.Filename),
                                             TU.inputs(FS), *BaselinePreamble);
   EXPECT_TRUE(PP.text().empty());
 }
 } // namespace
 } // namespace clangd
 } // namespace clang
	//===--- PreambleTests.cpp --------------------------------------- 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 "Annotations.h"
	#include "Compiler.h"
	#include "Headers.h"
	#include "Hover.h"
	#include "Preamble.h"
	#include "SourceCode.h"
	#include "TestFS.h"
	#include "TestTU.h"
	#include "XRefs.h"
	#include "clang/Format/Format.h"
	#include "clang/Frontend/PrecompiledPreamble.h"
	#include "clang/Lex/PreprocessorOptions.h"
	#include "llvm/ADT/STLExtras.h"
	#include "llvm/ADT/StringExtras.h"
	#include "llvm/ADT/StringRef.h"
	#include "llvm/Support/Error.h"
	#include "llvm/Support/MemoryBuffer.h"
	#include "llvm/Support/VirtualFileSystem.h"
	#include "gmock/gmock.h"
	#include "gtest/gtest.h"
	#include <clang/Frontend/FrontendActions.h>
	#include <memory>
	#include <string>
	#include <vector>

	using testing::Contains;
	using testing::Field;
	using testing::Matcher;
	using testing::MatchesRegex;

	namespace clang {
	namespace clangd {
	namespace {

	MATCHER_P2(Distance, File, D, "") {
	return arg.first() == File && arg.second == D;
	}

	// Builds a preamble for BaselineContents, patches it for ModifiedContents and
	// returns the includes in the patch.
	IncludeStructure
	collectPatchedIncludes(llvm::StringRef ModifiedContents,
	llvm::StringRef BaselineContents,
	llvm::StringRef MainFileName = "main.cpp") {
	MockFS FS;
	auto TU = TestTU::withCode(BaselineContents);
	TU.Filename = MainFileName.str();
	// ms-compatibility changes meaning of #import, make sure it is turned off.
	TU.ExtraArgs = {"-fno-ms-compatibility"};
	auto BaselinePreamble = TU.preamble();
	// Create the patch.
	TU.Code = ModifiedContents.str();
	auto PI = TU.inputs(FS);
	auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename), PI,
	*BaselinePreamble);
	// Collect patch contents.
	IgnoreDiagnostics Diags;
	auto CI = buildCompilerInvocation(PI, Diags);
	PP.apply(*CI);
	// Run preprocessor over the modified contents with patched Invocation. We
	// provide a preamble and trim contents to ensure only the implicit header
	// introduced by the patch is parsed and nothing else.
	// We don't run PP directly over the patch cotents to test production
	// behaviour.
	auto Bounds = Lexer::ComputePreamble(ModifiedContents, *CI->getLangOpts());
	auto Clang =
	prepareCompilerInstance(std::move(CI), &BaselinePreamble->Preamble,
	llvm::MemoryBuffer::getMemBufferCopy(
	ModifiedContents.slice(0, Bounds.Size).str()),
	PI.TFS->view(PI.CompileCommand.Directory), Diags);
	PreprocessOnlyAction Action;
	if (!Action.BeginSourceFile(*Clang, Clang->getFrontendOpts().Inputs[0])) {
	ADD_FAILURE() << "failed begin source file";
	return {};
	}
	IncludeStructure Includes;
	Clang->getPreprocessor().addPPCallbacks(
	Includes.collect(Clang->getSourceManager()));
	if (llvm::Error Err = Action.Execute()) {
	ADD_FAILURE() << "failed to execute action: " << std::move(Err);
	return {};
	}
	Action.EndSourceFile();
	return Includes;
	}

	// Check preamble lexing logic by building an empty preamble and patching it
	// with all the contents.
	TEST(PreamblePatchTest, IncludeParsing) {
	// We expect any line with a point to show up in the patch.
	llvm::StringRef Cases[] = {
	// Only preamble
	R"cpp(^#include "a.h")cpp",
	// Both preamble and mainfile
	R"cpp(
	^#include "a.h"
	garbage, finishes preamble
	#include "a.h")cpp",
	// Mixed directives
	R"cpp(
	^#include "a.h"
	#pragma directive
	// some comments
	^#include_next <a.h>
	#ifdef skipped
	^#import "a.h"
	#endif)cpp",
	// Broken directives
	R"cpp(
	#include "a
	^#include "a.h"
	#include <b
	^#include <b.h>)cpp",
	// Directive is not part of preamble if it is not the token immediately
	// followed by the hash (#).
	R"cpp(
	^#include "a.h"
	#/**/include <b.h>)cpp",
	};

	for (const auto &Case : Cases) {
	Annotations Test(Case);
	const auto Code = Test.code();
	SCOPED_TRACE(Code);

	auto Includes =
	collectPatchedIncludes(Code, /BaselineContents=/"").MainFileIncludes;
	auto Points = Test.points();
	ASSERT_EQ(Includes.size(), Points.size());
	for (size_t I = 0, E = Includes.size(); I != E; ++I)
	EXPECT_EQ(Includes[I].HashLine, Points[I].line);
	}
	}

	TEST(PreamblePatchTest, ContainsNewIncludes) {
	constexpr llvm::StringLiteral BaselineContents = R"cpp(
	#include <a.h>
	#include <b.h> // This will be removed
	#include <c.h>
	)cpp";
	constexpr llvm::StringLiteral ModifiedContents = R"cpp(
	#include <a.h>
	#include <c.h> // This has changed a line.
	#include <c.h> // This is a duplicate.
	#include <d.h> // This is newly introduced.
	)cpp";
	auto Includes = collectPatchedIncludes(ModifiedContents, BaselineContents)
	.MainFileIncludes;
	EXPECT_THAT(Includes, ElementsAre(AllOf(Field(&Inclusion::Written, "<d.h>"),
	Field(&Inclusion::HashLine, 4))));
	}

	TEST(PreamblePatchTest, MainFileIsEscaped) {
	auto Includes = collectPatchedIncludes("#include <a.h>", "", "file\"name.cpp")
	.MainFileIncludes;
	EXPECT_THAT(Includes, ElementsAre(AllOf(Field(&Inclusion::Written, "<a.h>"),
	Field(&Inclusion::HashLine, 0))));
	}

	TEST(PreamblePatchTest, PatchesPreambleIncludes) {
	MockFS FS;
	IgnoreDiagnostics Diags;
	auto TU = TestTU::withCode(R"cpp(
	#include "a.h"
	#include "c.h"
	)cpp");
	TU.AdditionalFiles["a.h"] = "#include \"b.h\"";
	TU.AdditionalFiles["b.h"] = "";
	TU.AdditionalFiles["c.h"] = "";
	auto PI = TU.inputs(FS);
	auto BaselinePreamble = buildPreamble(
	TU.Filename, *buildCompilerInvocation(PI, Diags), PI, true, nullptr);
	// We drop c.h from modified and add a new header. Since the latter is patched
	// we should only get a.h in preamble includes.
	TU.Code = R"cpp(
	#include "a.h"
	#include "b.h"
	)cpp";
	auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename), TU.inputs(FS),
	*BaselinePreamble);
	// Only a.h should exists in the preamble, as c.h has been dropped and b.h was
	// newly introduced.
	EXPECT_THAT(PP.preambleIncludes(),
	ElementsAre(AllOf(Field(&Inclusion::Written, "\"a.h\""),
	Field(&Inclusion::Resolved, testPath("a.h")))));
	}

	llvm::Optional<ParsedAST> createPatchedAST(llvm::StringRef Baseline,
	llvm::StringRef Modified) {
	auto BaselinePreamble = TestTU::withCode(Baseline).preamble();
	if (!BaselinePreamble) {
	ADD_FAILURE() << "Failed to build baseline preamble";
	return llvm::None;
	}

	IgnoreDiagnostics Diags;
	MockFS FS;
	auto TU = TestTU::withCode(Modified);
	auto CI = buildCompilerInvocation(TU.inputs(FS), Diags);
	if (!CI) {
	ADD_FAILURE() << "Failed to build compiler invocation";
	return llvm::None;
	}
	return ParsedAST::build(testPath(TU.Filename), TU.inputs(FS), std::move(CI),
	{}, BaselinePreamble);
	}

	std::string getPreamblePatch(llvm::StringRef Baseline,
	llvm::StringRef Modified) {
	auto BaselinePreamble = TestTU::withCode(Baseline).preamble();
	if (!BaselinePreamble) {
	ADD_FAILURE() << "Failed to build baseline preamble";
	return "";
	}
	MockFS FS;
	auto TU = TestTU::withCode(Modified);
	return PreamblePatch::createFullPatch(testPath("main.cpp"), TU.inputs(FS),
	*BaselinePreamble)
	.text()
	.str();
	}

	TEST(PreamblePatchTest, Define) {
	// BAR should be defined while parsing the AST.
	struct {
	const char *const Contents;
	const char *const ExpectedPatch;
	} Cases[] = {
	{
	R"cpp(
	#define BAR
	[[BAR]])cpp",
	R"cpp(#line 0 ".*main.cpp"
	#line 2
	#define BAR
	)cpp",
	},
	// multiline macro
	{
	R"cpp(
	#define BAR \

	[[BAR]])cpp",
	R"cpp(#line 0 ".*main.cpp"
	#line 2
	#define BAR
	)cpp",
	},
	// multiline macro
	{
	R"cpp(
	#define \
	BAR
	[[BAR]])cpp",
	R"cpp(#line 0 ".*main.cpp"
	#line 3
	#define BAR
	)cpp",
	},
	};

	for (const auto &Case : Cases) {
	SCOPED_TRACE(Case.Contents);
	Annotations Modified(Case.Contents);
	EXPECT_THAT(getPreamblePatch("", Modified.code()),
	MatchesRegex(Case.ExpectedPatch));

	auto AST = createPatchedAST("", Modified.code());
	ASSERT_TRUE(AST);
	std::vector<Range> MacroRefRanges;
	for (auto &M : AST->getMacros().MacroRefs) {
	for (auto &O : M.getSecond())
	MacroRefRanges.push_back(O.Rng);
	}
	EXPECT_THAT(MacroRefRanges, Contains(Modified.range()));
	}
	}

	TEST(PreamblePatchTest, OrderingPreserved) {
	llvm::StringLiteral Baseline = "#define BAR(X) X";
	Annotations Modified(R"cpp(
	#define BAR(X, Y) X Y
	#define BAR(X) X
	[[BAR]](int y);
	)cpp");

	llvm::StringLiteral ExpectedPatch(R"cpp(#line 0 ".*main.cpp"
	#line 2
	#define BAR\(X, Y\) X Y
	#line 3
	#define BAR\(X\) X
	)cpp");
	EXPECT_THAT(getPreamblePatch(Baseline, Modified.code()),
	MatchesRegex(ExpectedPatch.str()));

	auto AST = createPatchedAST(Baseline, Modified.code());
	ASSERT_TRUE(AST);
	}

	TEST(PreamblePatchTest, LocateMacroAtWorks) {
	struct {
	const char *const Baseline;
	const char *const Modified;
	} Cases[] = {
	// Addition of new directive
	{
	"",
	R"cpp(
	#define $def^FOO
	$use^FOO)cpp",
	},
	// Available inside preamble section
	{
	"",
	R"cpp(
	#define $def^FOO
	#undef $use^FOO)cpp",
	},
	// Available after undef, as we don't patch those
	{
	"",
	R"cpp(
	#define $def^FOO
	#undef FOO
	$use^FOO)cpp",
	},
	// Identifier on a different line
	{
	"",
	R"cpp(
	#define \
	$def^FOO
	$use^FOO)cpp",
	},
	// In presence of comment tokens
	{
	"",
	R"cpp(
	#\
	define /* FOO */\
	/* FOO */ $def^FOO
	$use^FOO)cpp",
	},
	// Moved around
	{
	"#define FOO",
	R"cpp(
	#define BAR
	#define $def^FOO
	$use^FOO)cpp",
	},
	};
	for (const auto &Case : Cases) {
	SCOPED_TRACE(Case.Modified);
	llvm::Annotations Modified(Case.Modified);
	auto AST = createPatchedAST(Case.Baseline, Modified.code());
	ASSERT_TRUE(AST);

	const auto &SM = AST->getSourceManager();
	auto *MacroTok = AST->getTokens().spelledTokenAt(
	SM.getComposedLoc(SM.getMainFileID(), Modified.point("use")));
	ASSERT_TRUE(MacroTok);

	auto FoundMacro = locateMacroAt(*MacroTok, AST->getPreprocessor());
	ASSERT_TRUE(FoundMacro);
	EXPECT_THAT(FoundMacro->Name, "FOO");

	auto MacroLoc = FoundMacro->NameLoc;
	EXPECT_EQ(SM.getFileID(MacroLoc), SM.getMainFileID());
	EXPECT_EQ(SM.getFileOffset(MacroLoc), Modified.point("def"));
	}
	}

	TEST(PreamblePatchTest, LocateMacroAtDeletion) {
	{
	// We don't patch deleted define directives, make sure we don't crash.
	llvm::StringLiteral Baseline = "#define FOO";
	llvm::Annotations Modified("^FOO");

	auto AST = createPatchedAST(Baseline, Modified.code());
	ASSERT_TRUE(AST);

	const auto &SM = AST->getSourceManager();
	auto *MacroTok = AST->getTokens().spelledTokenAt(
	SM.getComposedLoc(SM.getMainFileID(), Modified.point()));
	ASSERT_TRUE(MacroTok);

	auto FoundMacro = locateMacroAt(*MacroTok, AST->getPreprocessor());
	ASSERT_TRUE(FoundMacro);
	EXPECT_THAT(FoundMacro->Name, "FOO");
	auto HI =
	getHover(*AST, offsetToPosition(Modified.code(), Modified.point()),
	format::getLLVMStyle(), nullptr);
	ASSERT_TRUE(HI);
	EXPECT_THAT(HI->Definition, testing::IsEmpty());
	}

	{
	// Offset is valid, but underlying text is different.
	llvm::StringLiteral Baseline = "#define FOO";
	Annotations Modified(R"cpp(#define BAR
	^FOO")cpp");

	auto AST = createPatchedAST(Baseline, Modified.code());
	ASSERT_TRUE(AST);

	auto HI = getHover(*AST, Modified.point(), format::getLLVMStyle(), nullptr);
	ASSERT_TRUE(HI);
	EXPECT_THAT(HI->Definition, "#define BAR");
	}
	}

	MATCHER_P(referenceRangeIs, R, "") { return arg.Loc.range == R; }

	TEST(PreamblePatchTest, RefsToMacros) {
	struct {
	const char *const Baseline;
	const char *const Modified;
	} Cases[] = {
	// Newly added
	{
	"",
	R"cpp(
	#define ^FOO
	^[[FOO]])cpp",
	},
	// Moved around
	{
	"#define FOO",
	R"cpp(
	#define BAR
	#define ^FOO
	^[[FOO]])cpp",
	},
	// Ref in preamble section
	{
	"",
	R"cpp(
	#define ^FOO
	#undef ^FOO)cpp",
	},
	};

	for (const auto &Case : Cases) {
	Annotations Modified(Case.Modified);
	auto AST = createPatchedAST("", Modified.code());
	ASSERT_TRUE(AST);

	const auto &SM = AST->getSourceManager();
	std::vector<Matcher<ReferencesResult::Reference>> ExpectedLocations;
	for (const auto &R : Modified.ranges())
	ExpectedLocations.push_back(referenceRangeIs(R));

	for (const auto &P : Modified.points()) {
	auto *MacroTok = AST->getTokens().spelledTokenAt(SM.getComposedLoc(
	SM.getMainFileID(),
	llvm::cantFail(positionToOffset(Modified.code(), P))));
	ASSERT_TRUE(MacroTok);
	EXPECT_THAT(findReferences(*AST, P, 0).References,
	testing::ElementsAreArray(ExpectedLocations));
	}
	}
	}

	TEST(TranslatePreamblePatchLocation, Simple) {
	auto TU = TestTU::withHeaderCode(R"cpp(
	#line 3 "main.cpp"
	int foo();)cpp");
	// Presumed line/col needs to be valid in the main file.
	TU.Code = R"cpp(// line 1
	// line 2
	// line 3
	// line 4)cpp";
	TU.Filename = "main.cpp";
	TU.HeaderFilename = "__preamble_patch__.h";
	TU.ImplicitHeaderGuard = false;

	auto AST = TU.build();
	auto &SM = AST.getSourceManager();
	auto &ND = findDecl(AST, "foo");
	EXPECT_NE(SM.getFileID(ND.getLocation()), SM.getMainFileID());

	auto TranslatedLoc = translatePreamblePatchLocation(ND.getLocation(), SM);
	auto DecompLoc = SM.getDecomposedLoc(TranslatedLoc);
	EXPECT_EQ(DecompLoc.first, SM.getMainFileID());
	EXPECT_EQ(SM.getLineNumber(DecompLoc.first, DecompLoc.second), 3U);
	}

	TEST(PreamblePatch, ModifiedBounds) {
	struct {
	const char *const Baseline;
	const char *const Modified;
	} Cases[] = {
	// Size increased
	{
	"",
	R"cpp(
	#define FOO
	FOO)cpp",
	},
	// Stayed same
	{"#define FOO", "#define BAR"},
	// Got smaller
	{
	R"cpp(
	#define FOO
	#undef FOO)cpp",
	"#define FOO"},
	};

	for (const auto &Case : Cases) {
	auto TU = TestTU::withCode(Case.Baseline);
	auto BaselinePreamble = TU.preamble();
	ASSERT_TRUE(BaselinePreamble);

	Annotations Modified(Case.Modified);
	TU.Code = Modified.code().str();
	MockFS FS;
	auto PP = PreamblePatch::createFullPatch(testPath(TU.Filename),
	TU.inputs(FS), *BaselinePreamble);

	IgnoreDiagnostics Diags;
	auto CI = buildCompilerInvocation(TU.inputs(FS), Diags);
	ASSERT_TRUE(CI);

	const auto ExpectedBounds =
	Lexer::ComputePreamble(Case.Modified, *CI->getLangOpts());
	EXPECT_EQ(PP.modifiedBounds().Size, ExpectedBounds.Size);
	EXPECT_EQ(PP.modifiedBounds().PreambleEndsAtStartOfLine,
	ExpectedBounds.PreambleEndsAtStartOfLine);
	}
	}

	TEST(PreamblePatch, DropsDiagnostics) {
	llvm::StringLiteral Code = "#define FOO\nx;/* error-ok */";
	// First check that this code generates diagnostics.
	EXPECT_THAT(*TestTU::withCode(Code).build().getDiagnostics(),
	testing::Not(testing::IsEmpty()));
	// Ensure they are dropeed when a patched preamble is used.
	EXPECT_FALSE(createPatchedAST("", Code)->getDiagnostics());
	}

	TEST(PreamblePatch, MacroLoc) {
	llvm::StringLiteral Baseline = "\n#define MACRO 12\nint num = MACRO;";
	llvm::StringLiteral Modified = " \n#define MACRO 12\nint num = MACRO;";
	auto AST = createPatchedAST(Baseline, Modified);
	ASSERT_TRUE(AST);
	}

	TEST(PreamblePatch, NoopWhenNotRequested) {
	llvm::StringLiteral Baseline = "#define M\nint num = M;";
	llvm::StringLiteral Modified = "#define M\n#include <foo.h>\nint num = M;";
	auto TU = TestTU::withCode(Baseline);
	auto BaselinePreamble = TU.preamble();
	ASSERT_TRUE(BaselinePreamble);

	TU.Code = Modified.str();
	MockFS FS;
	auto PP = PreamblePatch::createMacroPatch(testPath(TU.Filename),
	TU.inputs(FS), *BaselinePreamble);
	EXPECT_TRUE(PP.text().empty());
	}
	} // namespace
	} // namespace clangd
	} // namespace clang