//===- CompilationDatabase.h ------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file provides an interface and multiple implementations for
// CompilationDatabases.
//
// While C++ refactoring and analysis tools are not compilers, and thus
// don't run as part of the build system, they need the exact information
// of a build in order to be able to correctly understand the C++ code of
// the project. This information is provided via the CompilationDatabase
// interface.
//
// To create a CompilationDatabase from a build directory one can call
// CompilationDatabase::loadFromDirectory(), which deduces the correct
// compilation database from the root of the build tree.
//
// See the concrete subclasses of CompilationDatabase for currently supported
// formats.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
#define LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/VirtualFileSystem.h"
#include <memory>
#include <string>
#include <utility>
#include <vector>
namespace clang {
namespace tooling {
/// Specifies the working directory and command of a compilation.
struct CompileCommand {
CompileCommand() = default;
CompileCommand(const Twine &Directory, const Twine &Filename,
std::vector<std::string> CommandLine, const Twine &Output)
: Directory(Directory.str()), Filename(Filename.str()),
CommandLine(std::move(CommandLine)), Output(Output.str()) {}
/// The working directory the command was executed from.
std::string Directory;
/// The source file associated with the command.
std::string Filename;
/// The command line that was executed.
std::vector<std::string> CommandLine;
/// The output file associated with the command.
std::string Output;
/// If this compile command was guessed rather than read from an authoritative
/// source, a short human-readable explanation.
/// e.g. "inferred from foo/bar.h".
std::string Heuristic;
friend bool operator==(const CompileCommand &LHS, const CompileCommand &RHS) {
return LHS.Directory == RHS.Directory && LHS.Filename == RHS.Filename &&
LHS.CommandLine == RHS.CommandLine && LHS.Output == RHS.Output &&
LHS.Heuristic == RHS.Heuristic;
}
friend bool operator!=(const CompileCommand &LHS, const CompileCommand &RHS) {
return !(LHS == RHS);
}
};
/// Interface for compilation databases.
///
/// A compilation database allows the user to retrieve compile command lines
/// for the files in a project.
///
/// Many implementations are enumerable, allowing all command lines to be
/// retrieved. These can be used to run clang tools over a subset of the files
/// in a project.
class CompilationDatabase {
public:
virtual ~CompilationDatabase();
/// Loads a compilation database from a build directory.
///
/// Looks at the specified 'BuildDirectory' and creates a compilation database
/// that allows to query compile commands for source files in the
/// corresponding source tree.
///
/// Returns NULL and sets ErrorMessage if we were not able to build up a
/// compilation database for the build directory.
///
/// FIXME: Currently only supports JSON compilation databases, which
/// are named 'compile_commands.json' in the given directory. Extend this
/// for other build types (like ninja build files).
static std::unique_ptr<CompilationDatabase>
loadFromDirectory(StringRef BuildDirectory, std::string &ErrorMessage);
/// Tries to detect a compilation database location and load it.
///
/// Looks for a compilation database in all parent paths of file 'SourceFile'
/// by calling loadFromDirectory.
static std::unique_ptr<CompilationDatabase>
autoDetectFromSource(StringRef SourceFile, std::string &ErrorMessage);
/// Tries to detect a compilation database location and load it.
///
/// Looks for a compilation database in directory 'SourceDir' and all
/// its parent paths by calling loadFromDirectory.
static std::unique_ptr<CompilationDatabase>
autoDetectFromDirectory(StringRef SourceDir, std::string &ErrorMessage);
/// Returns all compile commands in which the specified file was
/// compiled.
///
/// This includes compile commands that span multiple source files.
/// For example, consider a project with the following compilations:
/// $ clang++ -o test a.cc b.cc t.cc
/// $ clang++ -o production a.cc b.cc -DPRODUCTION
/// A compilation database representing the project would return both command
/// lines for a.cc and b.cc and only the first command line for t.cc.
virtual std::vector<CompileCommand> getCompileCommands(
StringRef FilePath) const = 0;
/// Returns the list of all files available in the compilation database.
///
/// By default, returns nothing. Implementations should override this if they
/// can enumerate their source files.
virtual std::vector<std::string> getAllFiles() const { return {}; }
/// Returns all compile commands for all the files in the compilation
/// database.
///
/// FIXME: Add a layer in Tooling that provides an interface to run a tool
/// over all files in a compilation database. Not all build systems have the
/// ability to provide a feasible implementation for \c getAllCompileCommands.
///
/// By default, this is implemented in terms of getAllFiles() and
/// getCompileCommands(). Subclasses may override this for efficiency.
virtual std::vector<CompileCommand> getAllCompileCommands() const;
};
/// A compilation database that returns a single compile command line.
///
/// Useful when we want a tool to behave more like a compiler invocation.
/// This compilation database is not enumerable: getAllFiles() returns {}.
class FixedCompilationDatabase : public CompilationDatabase {
public:
/// Creates a FixedCompilationDatabase from the arguments after "--".
///
/// Parses the given command line for "--". If "--" is found, the rest of
/// the arguments will make up the command line in the returned
/// FixedCompilationDatabase.
/// The arguments after "--" must not include positional parameters or the
/// argv[0] of the tool. Those will be added by the FixedCompilationDatabase
/// when a CompileCommand is requested. The argv[0] of the returned command
/// line will be "clang-tool".
///
/// Returns NULL in case "--" is not found.
///
/// The argument list is meant to be compatible with normal llvm command line
/// parsing in main methods.
/// int main(int argc, char **argv) {
/// std::unique_ptr<FixedCompilationDatabase> Compilations(
/// FixedCompilationDatabase::loadFromCommandLine(argc, argv));
/// cl::ParseCommandLineOptions(argc, argv);
/// ...
/// }
///
/// \param Argc The number of command line arguments - will be changed to
/// the number of arguments before "--", if "--" was found in the argument
/// list.
/// \param Argv Points to the command line arguments.
/// \param ErrorMsg Contains error text if the function returns null pointer.
/// \param Directory The base directory used in the FixedCompilationDatabase.
static std::unique_ptr<FixedCompilationDatabase>
loadFromCommandLine(int &Argc, const char *const *Argv, std::string &ErrorMsg,
const Twine &Directory = ".");
/// Reads flags from the given file, one-per-line.
/// Returns nullptr and sets ErrorMessage if we can't read the file.
static std::unique_ptr<FixedCompilationDatabase>
loadFromFile(StringRef Path, std::string &ErrorMsg);
/// Reads flags from the given buffer, one-per-line.
/// Directory is the command CWD, typically the parent of compile_flags.txt.
static std::unique_ptr<FixedCompilationDatabase>
loadFromBuffer(StringRef Directory, StringRef Data, std::string &ErrorMsg);
/// Constructs a compilation data base from a specified directory
/// and command line.
FixedCompilationDatabase(const Twine &Directory,
ArrayRef<std::string> CommandLine);
/// Returns the given compile command.
///
/// Will always return a vector with one entry that contains the directory
/// and command line specified at construction with "clang-tool" as argv[0]
/// and 'FilePath' as positional argument.
std::vector<CompileCommand>
getCompileCommands(StringRef FilePath) const override;
private:
/// This is built up to contain a single entry vector to be returned from
/// getCompileCommands after adding the positional argument.
std::vector<CompileCommand> CompileCommands;
};
/// Transforms a compile command so that it applies the same configuration to
/// a different file. Most args are left intact, but tweaks may be needed
/// to certain flags (-x, -std etc).
///
/// The output command will always end in {"--", Filename}.
tooling::CompileCommand transferCompileCommand(tooling::CompileCommand,
StringRef Filename);
/// Returns a wrapped CompilationDatabase that defers to the provided one,
/// but getCompileCommands() will infer commands for unknown files.
/// The return value of getAllFiles() or getAllCompileCommands() is unchanged.
/// See InterpolatingCompilationDatabase.cpp for details on heuristics.
std::unique_ptr<CompilationDatabase>
inferMissingCompileCommands(std::unique_ptr<CompilationDatabase>);
/// Returns a wrapped CompilationDatabase that will add -target and -mode flags
/// to commandline when they can be deduced from argv[0] of commandline returned
/// by underlying database.
std::unique_ptr<CompilationDatabase>
inferTargetAndDriverMode(std::unique_ptr<CompilationDatabase> Base);
/// Returns a wrapped CompilationDatabase that will expand all rsp(response)
/// files on commandline returned by underlying database.
std::unique_ptr<CompilationDatabase>
expandResponseFiles(std::unique_ptr<CompilationDatabase> Base,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS);
} // namespace tooling
} // namespace clang
#endif // LLVM_CLANG_TOOLING_COMPILATIONDATABASE_H