blob: c453e8d7df19206e4b18b4fc08dac296c72eb654 [file] [log] [blame]
//===- CompilationDatabase.cpp --------------------------------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file contains implementations of the CompilationDatabase base class
// and the FixedCompilationDatabase.
// FIXME: Various functions that take a string &ErrorMessage should be upgraded
// to Expected.
#include "clang/Tooling/CompilationDatabase.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticIDs.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/LLVM.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/ArrayRef.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Option/Arg.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/LineIterator.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstring>
#include <iterator>
#include <memory>
#include <sstream>
#include <string>
#include <system_error>
#include <utility>
#include <vector>
using namespace clang;
using namespace tooling;
CompilationDatabase::~CompilationDatabase() = default;
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;
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;
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;
std::vector<CompileCommand> CompilationDatabase::getAllCompileCommands() const {
std::vector<CompileCommand> Result;
for (const auto &File : getAllFiles()) {
auto C = getCompileCommands(File);
std::move(C.begin(), C.end(), std::back_inserter(Result));
return Result;
CompilationDatabasePlugin::~CompilationDatabasePlugin() = default;
namespace {
// Helper for recursively searching through a chain of actions and collecting
// all inputs, direct and indirect, of compile jobs.
struct CompileJobAnalyzer {
SmallVector<std::string, 2> Inputs;
void run(const driver::Action *A) {
runImpl(A, false);
void runImpl(const driver::Action *A, bool Collect) {
bool CollectChildren = Collect;
switch (A->getKind()) {
case driver::Action::CompileJobClass:
CollectChildren = true;
case driver::Action::InputClass:
if (Collect) {
const auto *IA = cast<driver::InputAction>(A);
// 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 {
UnusedInputDiagConsumer(DiagnosticConsumer &Other) : Other(Other) {}
void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
const Diagnostic &Info) override {
if (Info.getID() == diag::warn_drv_input_file_unused) {
// Arg 1 for this diagnostic is the option that didn't get used.
} else if (DiagLevel >= DiagnosticsEngine::Error) {
// If driver failed to create compilation object, show the diagnostics
// to user.
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;
ArrayRef<std::string> Arr;
// Filter of tools unused flags such as -no-integrated-as and -Wa,*.
// They are not used for syntax checking, and could confuse targets
// which don't support these options.
struct FilterUnusedFlags {
bool operator() (StringRef S) {
return (S == "-no-integrated-as") || S.startswith("-Wa,");
std::string GetClangToolCommand() {
static int Dummy;
std::string ClangExecutable =
llvm::sys::fs::getMainExecutable("clang", (void *)&Dummy);
SmallString<128> ClangToolPath;
ClangToolPath = llvm::sys::path::parent_path(ClangExecutable);
llvm::sys::path::append(ClangToolPath, "clang-tool");
return ClangToolPath.str();
} // namespace
/// 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,
std::string &ErrorMsg) {
IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
llvm::raw_string_ostream Output(ErrorMsg);
TextDiagnosticPrinter DiagnosticPrinter(Output, &*DiagOpts);
UnusedInputDiagConsumer DiagClient(DiagnosticPrinter);
DiagnosticsEngine Diagnostics(
IntrusiveRefCntPtr<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(),
// This becomes the new argv[0]. The value is used to detect libc++ include
// dirs on Mac, it isn't used for other platforms.
std::string Argv0 = GetClangToolCommand();
Args.insert(Args.begin(), Argv0.c_str());
// 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.
// 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.erase(std::remove_if(Args.begin(), Args.end(), FilterUnusedFlags()),
const std::unique_ptr<driver::Compilation> Compilation(
if (!Compilation)
return false;
const driver::JobList &Jobs = Compilation->getJobs();
CompileJobAnalyzer CompileAnalyzer;
for (const auto &Cmd : Jobs) {
// Collect only for Assemble, Backend, and Compile jobs. If we do all jobs
// we get duplicates since Link jobs point to Assemble jobs as inputs.
// -flto* flags make the BackendJobClass, which still needs analyzer.
if (Cmd.getSource().getKind() == driver::Action::AssembleJobClass ||
Cmd.getSource().getKind() == driver::Action::BackendJobClass ||
Cmd.getSource().getKind() == driver::Action::CompileJobClass) {;
if (CompileAnalyzer.Inputs.empty()) {
ErrorMsg = "warning: no compile jobs found\n";
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);
Result = std::vector<std::string>(Args.begin() + 1, End);
return true;
FixedCompilationDatabase::loadFromCommandLine(int &Argc,
const char *const *Argv,
std::string &ErrorMsg,
Twine Directory) {
if (Argc == 0)
return nullptr;
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, ErrorMsg))
return nullptr;
return std::make_unique<FixedCompilationDatabase>(Directory, StrippedArgs);
FixedCompilationDatabase::loadFromFile(StringRef Path, std::string &ErrorMsg) {
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
if (std::error_code Result = File.getError()) {
ErrorMsg = "Error while opening fixed database: " + Result.message();
return nullptr;
std::vector<std::string> Args{llvm::line_iterator(**File),
return std::make_unique<FixedCompilationDatabase>(
llvm::sys::path::parent_path(Path), std::move(Args));
FixedCompilationDatabase(Twine Directory, ArrayRef<std::string> CommandLine) {
std::vector<std::string> ToolCommandLine(1, GetClangToolCommand());
CommandLine.begin(), CommandLine.end());
CompileCommands.emplace_back(Directory, StringRef(),
FixedCompilationDatabase::getCompileCommands(StringRef FilePath) const {
std::vector<CompileCommand> Result(CompileCommands);
Result[0].Filename = FilePath;
return Result;
namespace {
class FixedCompilationDatabasePlugin : public CompilationDatabasePlugin {
loadFromDirectory(StringRef Directory, std::string &ErrorMessage) override {
SmallString<1024> DatabasePath(Directory);
llvm::sys::path::append(DatabasePath, "compile_flags.txt");
return FixedCompilationDatabase::loadFromFile(DatabasePath, ErrorMessage);
} // namespace
static CompilationDatabasePluginRegistry::Add<FixedCompilationDatabasePlugin>
X("fixed-compilation-database", "Reads plain-text flags file");
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;
} // namespace tooling
} // namespace clang