lib/Tooling/CompilationDatabase.cpp - third_party/swift-clang - Git at Google

 //===--- CompilationDatabase.cpp - ----------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file contains implementations of the CompilationDatabase base class
 //  and the FixedCompilationDatabase.
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Tooling/CompilationDatabase.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Driver/Action.h"
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Job.h"
 #include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "clang/Tooling/CompilationDatabasePluginRegistry.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
 #include <sstream>
 #include <system_error>
 using namespace clang;
 using namespace tooling;

 LLVM_INSTANTIATE_REGISTRY(CompilationDatabasePluginRegistry)

 CompilationDatabase::~CompilationDatabase() {}

 std::unique_ptr<CompilationDatabase>
 CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
                                        std::string &ErrorMessage) {
   llvm::raw_string_ostream ErrorStream(ErrorMessage);
   for (CompilationDatabasePluginRegistry::iterator
        It = CompilationDatabasePluginRegistry::begin(),
        Ie = CompilationDatabasePluginRegistry::end();
        It != Ie; ++It) {
     std::string DatabaseErrorMessage;
     std::unique_ptr<CompilationDatabasePlugin> Plugin(It->instantiate());
     if (std::unique_ptr<CompilationDatabase> DB =
             Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
       return DB;
     ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
   }
   return nullptr;
 }

 static std::unique_ptr<CompilationDatabase>
 findCompilationDatabaseFromDirectory(StringRef Directory,
                                      std::string &ErrorMessage) {
   std::stringstream ErrorStream;
   bool HasErrorMessage = false;
   while (!Directory.empty()) {
     std::string LoadErrorMessage;

     if (std::unique_ptr<CompilationDatabase> DB =
             CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
       return DB;

     if (!HasErrorMessage) {
       ErrorStream << "No compilation database found in " << Directory.str()
                   << " or any parent directory\n" << LoadErrorMessage;
       HasErrorMessage = true;
     }

     Directory = llvm::sys::path::parent_path(Directory);
   }
   ErrorMessage = ErrorStream.str();
   return nullptr;
 }

 std::unique_ptr<CompilationDatabase>
 CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
                                           std::string &ErrorMessage) {
   SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
   StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);

   std::unique_ptr<CompilationDatabase> DB =
       findCompilationDatabaseFromDirectory(Directory, ErrorMessage);

   if (!DB)
     ErrorMessage = ("Could not auto-detect compilation database for file \"" +
                    SourceFile + "\"\n" + ErrorMessage).str();
   return DB;
 }

 std::unique_ptr<CompilationDatabase>
 CompilationDatabase::autoDetectFromDirectory(StringRef SourceDir,
                                              std::string &ErrorMessage) {
   SmallString<1024> AbsolutePath(getAbsolutePath(SourceDir));

   std::unique_ptr<CompilationDatabase> DB =
       findCompilationDatabaseFromDirectory(AbsolutePath, ErrorMessage);

   if (!DB)
     ErrorMessage = ("Could not auto-detect compilation database from directory \"" +
                    SourceDir + "\"\n" + ErrorMessage).str();
   return DB;
 }

 CompilationDatabasePlugin::~CompilationDatabasePlugin() {}

 namespace {
 // Helper for recursively searching through a chain of actions and collecting
 // all inputs, direct and indirect, of compile jobs.
 struct CompileJobAnalyzer {
   void run(const driver::Action *A) {
     runImpl(A, false);
   }

   SmallVector<std::string, 2> Inputs;

 private:

   void runImpl(const driver::Action *A, bool Collect) {
     bool CollectChildren = Collect;
     switch (A->getKind()) {
     case driver::Action::CompileJobClass:
       CollectChildren = true;
       break;

     case driver::Action::InputClass: {
       if (Collect) {
         const driver::InputAction *IA = cast<driver::InputAction>(A);
         Inputs.push_back(IA->getInputArg().getSpelling());
       }
     } break;

     default:
       // Don't care about others
       ;
     }

     for (const driver::Action *AI : A->inputs())
       runImpl(AI, CollectChildren);
   }
 };

 // Special DiagnosticConsumer that looks for warn_drv_input_file_unused
 // diagnostics from the driver and collects the option strings for those unused
 // options.
 class UnusedInputDiagConsumer : public DiagnosticConsumer {
 public:
   UnusedInputDiagConsumer() : Other(nullptr) {}

   // Useful for debugging, chain diagnostics to another consumer after
   // recording for our own purposes.
   UnusedInputDiagConsumer(DiagnosticConsumer *Other) : Other(Other) {}

   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
                         const Diagnostic &Info) override {
     if (Info.getID() == clang::diag::warn_drv_input_file_unused) {
       // Arg 1 for this diagnostic is the option that didn't get used.
       UnusedInputs.push_back(Info.getArgStdStr(0));
     }
     if (Other)
       Other->HandleDiagnostic(DiagLevel, Info);
   }

   DiagnosticConsumer *Other;
   SmallVector<std::string, 2> UnusedInputs;
 };

 // Unary functor for asking "Given a StringRef S1, does there exist a string
 // S2 in Arr where S1 == S2?"
 struct MatchesAny {
   MatchesAny(ArrayRef<std::string> Arr) : Arr(Arr) {}
   bool operator() (StringRef S) {
     for (const std::string *I = Arr.begin(), *E = Arr.end(); I != E; ++I)
       if (*I == S)
         return true;
     return false;
   }
 private:
   ArrayRef<std::string> Arr;
 };
 } // namespace

 /// \brief Strips any positional args and possible argv[0] from a command-line
 /// provided by the user to construct a FixedCompilationDatabase.
 ///
 /// FixedCompilationDatabase requires a command line to be in this format as it
 /// constructs the command line for each file by appending the name of the file
 /// to be compiled. FixedCompilationDatabase also adds its own argv[0] to the
 /// start of the command line although its value is not important as it's just
 /// ignored by the Driver invoked by the ClangTool using the
 /// FixedCompilationDatabase.
 ///
 /// FIXME: This functionality should probably be made available by
 /// clang::driver::Driver although what the interface should look like is not
 /// clear.
 ///
 /// \param[in] Args Args as provided by the user.
 /// \return Resulting stripped command line.
 ///          \li true if successful.
 ///          \li false if \c Args cannot be used for compilation jobs (e.g.
 ///          contains an option like -E or -version).
 static bool stripPositionalArgs(std::vector<const char *> Args,
                                 std::vector<std::string> &Result) {
   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
   UnusedInputDiagConsumer DiagClient;
   DiagnosticsEngine Diagnostics(
       IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
       &*DiagOpts, &DiagClient, false);

   // The clang executable path isn't required since the jobs the driver builds
   // will not be executed.
   std::unique_ptr<driver::Driver> NewDriver(new driver::Driver(
       /* ClangExecutable= */ "", llvm::sys::getDefaultTargetTriple(),
       Diagnostics));
   NewDriver->setCheckInputsExist(false);

   // This becomes the new argv[0]. The value is actually not important as it
   // isn't used for invoking Tools.
   Args.insert(Args.begin(), "clang-tool");

   // By adding -c, we force the driver to treat compilation as the last phase.
   // It will then issue warnings via Diagnostics about un-used options that
   // would have been used for linking. If the user provided a compiler name as
   // the original argv[0], this will be treated as a linker input thanks to
   // insertng a new argv[0] above. All un-used options get collected by
   // UnusedInputdiagConsumer and get stripped out later.
   Args.push_back("-c");

   // Put a dummy C++ file on to ensure there's at least one compile job for the
   // driver to construct. If the user specified some other argument that
   // prevents compilation, e.g. -E or something like -version, we may still end
   // up with no jobs but then this is the user's fault.
   Args.push_back("placeholder.cpp");

   // Remove -no-integrated-as; it's not used for syntax checking,
   // and it confuses targets which don't support this option.
   Args.erase(std::remove_if(Args.begin(), Args.end(),
                             MatchesAny(std::string("-no-integrated-as"))),
              Args.end());

   const std::unique_ptr<driver::Compilation> Compilation(
       NewDriver->BuildCompilation(Args));

   const driver::JobList &Jobs = Compilation->getJobs();

   CompileJobAnalyzer CompileAnalyzer;

   for (const auto &Cmd : Jobs) {
     // Collect only for Assemble jobs. If we do all jobs we get duplicates
     // since Link jobs point to Assemble jobs as inputs.
     if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass)
       CompileAnalyzer.run(&Cmd.getSource());
   }

   if (CompileAnalyzer.Inputs.empty()) {
     // No compile jobs found.
     // FIXME: Emit a warning of some kind?
     return false;
   }

   // Remove all compilation input files from the command line. This is
   // necessary so that getCompileCommands() can construct a command line for
   // each file.
   std::vector<const char *>::iterator End = std::remove_if(
       Args.begin(), Args.end(), MatchesAny(CompileAnalyzer.Inputs));

   // Remove all inputs deemed unused for compilation.
   End = std::remove_if(Args.begin(), End, MatchesAny(DiagClient.UnusedInputs));

   // Remove the -c add above as well. It will be at the end right now.
   assert(strcmp(*(End - 1), "-c") == 0);
   --End;

   Result = std::vector<std::string>(Args.begin() + 1, End);
   return true;
 }

 FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
     int &Argc, const char *const *Argv, Twine Directory) {
   const char *const *DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
   if (DoubleDash == Argv + Argc)
     return nullptr;
   std::vector<const char *> CommandLine(DoubleDash + 1, Argv + Argc);
   Argc = DoubleDash - Argv;

   std::vector<std::string> StrippedArgs;
   if (!stripPositionalArgs(CommandLine, StrippedArgs))
     return nullptr;
   return new FixedCompilationDatabase(Directory, StrippedArgs);
 }

 FixedCompilationDatabase::
 FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
   std::vector<std::string> ToolCommandLine(1, "clang-tool");
   ToolCommandLine.insert(ToolCommandLine.end(),
                          CommandLine.begin(), CommandLine.end());
   CompileCommands.emplace_back(Directory, StringRef(),
                                std::move(ToolCommandLine),
                                StringRef());
 }

 std::vector<CompileCommand>
 FixedCompilationDatabase::getCompileCommands(StringRef FilePath) const {
   std::vector<CompileCommand> Result(CompileCommands);
   Result[0].CommandLine.push_back(FilePath);
   Result[0].Filename = FilePath;
   return Result;
 }

 std::vector<std::string>
 FixedCompilationDatabase::getAllFiles() const {
   return std::vector<std::string>();
 }

 std::vector<CompileCommand>
 FixedCompilationDatabase::getAllCompileCommands() const {
   return std::vector<CompileCommand>();
 }

 namespace clang {
 namespace tooling {

 // This anchor is used to force the linker to link in the generated object file
 // and thus register the JSONCompilationDatabasePlugin.
 extern volatile int JSONAnchorSource;
 static int LLVM_ATTRIBUTE_UNUSED JSONAnchorDest = JSONAnchorSource;

 } // end namespace tooling
 } // end namespace clang
	//===--- CompilationDatabase.cpp - ----------------------------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file contains implementations of the CompilationDatabase base class
	// and the FixedCompilationDatabase.
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Tooling/CompilationDatabase.h"
	#include "clang/Basic/Diagnostic.h"
	#include "clang/Basic/DiagnosticOptions.h"
	#include "clang/Driver/Action.h"
	#include "clang/Driver/Compilation.h"
	#include "clang/Driver/Driver.h"
	#include "clang/Driver/DriverDiagnostic.h"
	#include "clang/Driver/Job.h"
	#include "clang/Frontend/TextDiagnosticPrinter.h"
	#include "clang/Tooling/CompilationDatabasePluginRegistry.h"
	#include "clang/Tooling/Tooling.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/Option/Arg.h"
	#include "llvm/Support/Host.h"
	#include "llvm/Support/Path.h"
	#include <sstream>
	#include <system_error>
	using namespace clang;
	using namespace tooling;

	LLVM_INSTANTIATE_REGISTRY(CompilationDatabasePluginRegistry)

	CompilationDatabase::~CompilationDatabase() {}

	std::unique_ptr<CompilationDatabase>
	CompilationDatabase::loadFromDirectory(StringRef BuildDirectory,
	std::string &ErrorMessage) {
	llvm::raw_string_ostream ErrorStream(ErrorMessage);
	for (CompilationDatabasePluginRegistry::iterator
	It = CompilationDatabasePluginRegistry::begin(),
	Ie = CompilationDatabasePluginRegistry::end();
	It != Ie; ++It) {
	std::string DatabaseErrorMessage;
	std::unique_ptr<CompilationDatabasePlugin> Plugin(It->instantiate());
	if (std::unique_ptr<CompilationDatabase> DB =
	Plugin->loadFromDirectory(BuildDirectory, DatabaseErrorMessage))
	return DB;
	ErrorStream << It->getName() << ": " << DatabaseErrorMessage << "\n";
	}
	return nullptr;
	}

	static std::unique_ptr<CompilationDatabase>
	findCompilationDatabaseFromDirectory(StringRef Directory,
	std::string &ErrorMessage) {
	std::stringstream ErrorStream;
	bool HasErrorMessage = false;
	while (!Directory.empty()) {
	std::string LoadErrorMessage;

	if (std::unique_ptr<CompilationDatabase> DB =
	CompilationDatabase::loadFromDirectory(Directory, LoadErrorMessage))
	return DB;

	if (!HasErrorMessage) {
	ErrorStream << "No compilation database found in " << Directory.str()
	<< " or any parent directory\n" << LoadErrorMessage;
	HasErrorMessage = true;
	}

	Directory = llvm::sys::path::parent_path(Directory);
	}
	ErrorMessage = ErrorStream.str();
	return nullptr;
	}

	std::unique_ptr<CompilationDatabase>
	CompilationDatabase::autoDetectFromSource(StringRef SourceFile,
	std::string &ErrorMessage) {
	SmallString<1024> AbsolutePath(getAbsolutePath(SourceFile));
	StringRef Directory = llvm::sys::path::parent_path(AbsolutePath);

	std::unique_ptr<CompilationDatabase> DB =
	findCompilationDatabaseFromDirectory(Directory, ErrorMessage);

	if (!DB)
	ErrorMessage = ("Could not auto-detect compilation database for file \"" +
	SourceFile + "\"\n" + ErrorMessage).str();
	return DB;
	}

	std::unique_ptr<CompilationDatabase>
	CompilationDatabase::autoDetectFromDirectory(StringRef SourceDir,
	std::string &ErrorMessage) {
	SmallString<1024> AbsolutePath(getAbsolutePath(SourceDir));

	std::unique_ptr<CompilationDatabase> DB =
	findCompilationDatabaseFromDirectory(AbsolutePath, ErrorMessage);

	if (!DB)
	ErrorMessage = ("Could not auto-detect compilation database from directory \"" +
	SourceDir + "\"\n" + ErrorMessage).str();
	return DB;
	}

	CompilationDatabasePlugin::~CompilationDatabasePlugin() {}

	namespace {
	// Helper for recursively searching through a chain of actions and collecting
	// all inputs, direct and indirect, of compile jobs.
	struct CompileJobAnalyzer {
	void run(const driver::Action *A) {
	runImpl(A, false);
	}

	SmallVector<std::string, 2> Inputs;

	private:

	void runImpl(const driver::Action *A, bool Collect) {
	bool CollectChildren = Collect;
	switch (A->getKind()) {
	case driver::Action::CompileJobClass:
	CollectChildren = true;
	break;

	case driver::Action::InputClass: {
	if (Collect) {
	const driver::InputAction *IA = cast<driver::InputAction>(A);
	Inputs.push_back(IA->getInputArg().getSpelling());
	}
	} break;

	default:
	// Don't care about others
	;
	}

	for (const driver::Action *AI : A->inputs())
	runImpl(AI, CollectChildren);
	}
	};

	// Special DiagnosticConsumer that looks for warn_drv_input_file_unused
	// diagnostics from the driver and collects the option strings for those unused
	// options.
	class UnusedInputDiagConsumer : public DiagnosticConsumer {
	public:
	UnusedInputDiagConsumer() : Other(nullptr) {}

	// Useful for debugging, chain diagnostics to another consumer after
	// recording for our own purposes.
	UnusedInputDiagConsumer(DiagnosticConsumer *Other) : Other(Other) {}

	void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
	const Diagnostic &Info) override {
	if (Info.getID() == clang::diag::warn_drv_input_file_unused) {
	// Arg 1 for this diagnostic is the option that didn't get used.
	UnusedInputs.push_back(Info.getArgStdStr(0));
	}
	if (Other)
	Other->HandleDiagnostic(DiagLevel, Info);
	}

	DiagnosticConsumer *Other;
	SmallVector<std::string, 2> UnusedInputs;
	};

	// Unary functor for asking "Given a StringRef S1, does there exist a string
	// S2 in Arr where S1 == S2?"
	struct MatchesAny {
	MatchesAny(ArrayRef<std::string> Arr) : Arr(Arr) {}
	bool operator() (StringRef S) {
	for (const std::string I = Arr.begin(), E = Arr.end(); I != E; ++I)
	if (*I == S)
	return true;
	return false;
	}
	private:
	ArrayRef<std::string> Arr;
	};
	} // namespace

	/// \brief Strips any positional args and possible argv[0] from a command-line
	/// provided by the user to construct a FixedCompilationDatabase.
	///
	/// FixedCompilationDatabase requires a command line to be in this format as it
	/// constructs the command line for each file by appending the name of the file
	/// to be compiled. FixedCompilationDatabase also adds its own argv[0] to the
	/// start of the command line although its value is not important as it's just
	/// ignored by the Driver invoked by the ClangTool using the
	/// FixedCompilationDatabase.
	///
	/// FIXME: This functionality should probably be made available by
	/// clang::driver::Driver although what the interface should look like is not
	/// clear.
	///
	/// \param[in] Args Args as provided by the user.
	/// \return Resulting stripped command line.
	/// \li true if successful.
	/// \li false if \c Args cannot be used for compilation jobs (e.g.
	/// contains an option like -E or -version).
	static bool stripPositionalArgs(std::vector<const char *> Args,
	std::vector<std::string> &Result) {
	IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
	UnusedInputDiagConsumer DiagClient;
	DiagnosticsEngine Diagnostics(
	IntrusiveRefCntPtr<clang::DiagnosticIDs>(new DiagnosticIDs()),
	&*DiagOpts, &DiagClient, false);

	// The clang executable path isn't required since the jobs the driver builds
	// will not be executed.
	std::unique_ptr<driver::Driver> NewDriver(new driver::Driver(
	/* ClangExecutable= */ "", llvm::sys::getDefaultTargetTriple(),
	Diagnostics));
	NewDriver->setCheckInputsExist(false);

	// This becomes the new argv[0]. The value is actually not important as it
	// isn't used for invoking Tools.
	Args.insert(Args.begin(), "clang-tool");

	// By adding -c, we force the driver to treat compilation as the last phase.
	// It will then issue warnings via Diagnostics about un-used options that
	// would have been used for linking. If the user provided a compiler name as
	// the original argv[0], this will be treated as a linker input thanks to
	// insertng a new argv[0] above. All un-used options get collected by
	// UnusedInputdiagConsumer and get stripped out later.
	Args.push_back("-c");

	// Put a dummy C++ file on to ensure there's at least one compile job for the
	// driver to construct. If the user specified some other argument that
	// prevents compilation, e.g. -E or something like -version, we may still end
	// up with no jobs but then this is the user's fault.
	Args.push_back("placeholder.cpp");

	// Remove -no-integrated-as; it's not used for syntax checking,
	// and it confuses targets which don't support this option.
	Args.erase(std::remove_if(Args.begin(), Args.end(),
	MatchesAny(std::string("-no-integrated-as"))),
	Args.end());

	const std::unique_ptr<driver::Compilation> Compilation(
	NewDriver->BuildCompilation(Args));

	const driver::JobList &Jobs = Compilation->getJobs();

	CompileJobAnalyzer CompileAnalyzer;

	for (const auto &Cmd : Jobs) {
	// Collect only for Assemble jobs. If we do all jobs we get duplicates
	// since Link jobs point to Assemble jobs as inputs.
	if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass)
	CompileAnalyzer.run(&Cmd.getSource());
	}

	if (CompileAnalyzer.Inputs.empty()) {
	// No compile jobs found.
	// FIXME: Emit a warning of some kind?
	return false;
	}

	// Remove all compilation input files from the command line. This is
	// necessary so that getCompileCommands() can construct a command line for
	// each file.
	std::vector<const char *>::iterator End = std::remove_if(
	Args.begin(), Args.end(), MatchesAny(CompileAnalyzer.Inputs));

	// Remove all inputs deemed unused for compilation.
	End = std::remove_if(Args.begin(), End, MatchesAny(DiagClient.UnusedInputs));

	// Remove the -c add above as well. It will be at the end right now.
	assert(strcmp(*(End - 1), "-c") == 0);
	--End;

	Result = std::vector<std::string>(Args.begin() + 1, End);
	return true;
	}

	FixedCompilationDatabase *FixedCompilationDatabase::loadFromCommandLine(
	int &Argc, const char const Argv, Twine Directory) {
	const char const DoubleDash = std::find(Argv, Argv + Argc, StringRef("--"));
	if (DoubleDash == Argv + Argc)
	return nullptr;
	std::vector<const char *> CommandLine(DoubleDash + 1, Argv + Argc);
	Argc = DoubleDash - Argv;

	std::vector<std::string> StrippedArgs;
	if (!stripPositionalArgs(CommandLine, StrippedArgs))
	return nullptr;
	return new FixedCompilationDatabase(Directory, StrippedArgs);
	}

	FixedCompilationDatabase::
	FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
	std::vector<std::string> ToolCommandLine(1, "clang-tool");
	ToolCommandLine.insert(ToolCommandLine.end(),
	CommandLine.begin(), CommandLine.end());
	CompileCommands.emplace_back(Directory, StringRef(),
	std::move(ToolCommandLine),
	StringRef());
	}

	std::vector<CompileCommand>
	FixedCompilationDatabase::getCompileCommands(StringRef FilePath) const {
	std::vector<CompileCommand> Result(CompileCommands);
	Result[0].CommandLine.push_back(FilePath);
	Result[0].Filename = FilePath;
	return Result;
	}

	std::vector<std::string>
	FixedCompilationDatabase::getAllFiles() const {
	return std::vector<std::string>();
	}

	std::vector<CompileCommand>
	FixedCompilationDatabase::getAllCompileCommands() const {
	return std::vector<CompileCommand>();
	}

	namespace clang {
	namespace tooling {

	// This anchor is used to force the linker to link in the generated object file
	// and thus register the JSONCompilationDatabasePlugin.
	extern volatile int JSONAnchorSource;
	static int LLVM_ATTRIBUTE_UNUSED JSONAnchorDest = JSONAnchorSource;

	} // end namespace tooling
	} // end namespace clang