llvm-project/clang-tools-extra/clangd/GlobalCompilationDatabase.h

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//===--- GlobalCompilationDatabase.h -----------------------------*- C++-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_GLOBALCOMPILATIONDATABASE_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_GLOBALCOMPILATIONDATABASE_H
#include "Function.h"
#include "Path.h"
#include "llvm/ADT/StringMap.h"
#include <memory>
#include <mutex>
#include <vector>
namespace clang {
namespace tooling {
class CompilationDatabase;
struct CompileCommand;
} // namespace tooling
namespace clangd {
class Logger;
struct ProjectInfo {
// The directory in which the compilation database was discovered.
// Empty if directory-based compilation database discovery was not used.
std::string SourceRoot;
};
/// Provides compilation arguments used for parsing C and C++ files.
class GlobalCompilationDatabase {
public:
virtual ~GlobalCompilationDatabase() = default;
/// If there are any known-good commands for building this file, returns one.
/// If the ProjectInfo pointer is set, it will also be populated.
virtual llvm::Optional<tooling::CompileCommand>
getCompileCommand(PathRef File, ProjectInfo * = nullptr) const = 0;
/// Makes a guess at how to build a file.
/// The default implementation just runs clang on the file.
/// Clangd should treat the results as unreliable.
virtual tooling::CompileCommand getFallbackCommand(PathRef File) const;
using CommandChanged = Event<std::vector<std::string>>;
/// The callback is notified when files may have new compile commands.
/// The argument is a list of full file paths.
CommandChanged::Subscription watch(CommandChanged::Listener L) const {
return OnCommandChanged.observe(std::move(L));
}
protected:
mutable CommandChanged OnCommandChanged;
};
/// Gets compile args from tooling::CompilationDatabases built for parent
/// directories.
class DirectoryBasedGlobalCompilationDatabase
: public GlobalCompilationDatabase {
public:
DirectoryBasedGlobalCompilationDatabase(
llvm::Optional<Path> CompileCommandsDir);
~DirectoryBasedGlobalCompilationDatabase() override;
/// Scans File's parents looking for compilation databases.
/// Any extra flags will be added.
llvm::Optional<tooling::CompileCommand>
getCompileCommand(PathRef File, ProjectInfo * = nullptr) const override;
private:
tooling::CompilationDatabase *getCDBForFile(PathRef File,
ProjectInfo *) const;
std::pair<tooling::CompilationDatabase *, /*Cached*/ bool>
getCDBInDirLocked(PathRef File) const;
mutable std::mutex Mutex;
/// Caches compilation databases loaded from directories(keys are
/// directories).
mutable llvm::StringMap<std::unique_ptr<clang::tooling::CompilationDatabase>>
CompilationDatabases;
/// Used for command argument pointing to folder where compile_commands.json
/// is located.
llvm::Optional<Path> CompileCommandsDir;
};
/// Wraps another compilation database, and supports overriding the commands
/// using an in-memory mapping.
class OverlayCDB : public GlobalCompilationDatabase {
public:
// Base may be null, in which case no entries are inherited.
// FallbackFlags are added to the fallback compile command.
OverlayCDB(const GlobalCompilationDatabase *Base,
std::vector<std::string> FallbackFlags = {});
llvm::Optional<tooling::CompileCommand>
getCompileCommand(PathRef File, ProjectInfo * = nullptr) const override;
tooling::CompileCommand getFallbackCommand(PathRef File) const override;
/// Sets or clears the compilation command for a particular file.
void
setCompileCommand(PathRef File,
llvm::Optional<tooling::CompileCommand> CompilationCommand);
private:
mutable std::mutex Mutex;
llvm::StringMap<tooling::CompileCommand> Commands; /* GUARDED_BY(Mut) */
const GlobalCompilationDatabase *Base;
std::vector<std::string> FallbackFlags;
CommandChanged::Subscription BaseChanged;
};
} // namespace clangd
} // namespace clang
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_GLOBALCOMPILATIONDATABASE_H