//===- Utils.h - Misc utilities for the front-end ---------------*- 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 header contains miscellaneous utilities for various front-end actions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_FRONTEND_UTILS_H
#define LLVM_CLANG_FRONTEND_UTILS_H
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LLVM.h"
#include "clang/Driver/OptionUtils.h"
#include "clang/Frontend/DependencyOutputOptions.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Support/FileCollector.h"
#include "llvm/Support/VirtualFileSystem.h"
#include <cstdint>
#include <memory>
#include <string>
#include <system_error>
#include <utility>
#include <vector>
namespace clang {
class ASTReader;
class CompilerInstance;
class CompilerInvocation;
class DiagnosticsEngine;
class ExternalSemaSource;
class FrontendOptions;
class PCHContainerReader;
class Preprocessor;
class PreprocessorOptions;
class PreprocessorOutputOptions;
/// InitializePreprocessor - Initialize the preprocessor getting it and the
/// environment ready to process a single file.
void InitializePreprocessor(Preprocessor &PP, const PreprocessorOptions &PPOpts,
const PCHContainerReader &PCHContainerRdr,
const FrontendOptions &FEOpts);
/// DoPrintPreprocessedInput - Implement -E mode.
void DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
const PreprocessorOutputOptions &Opts);
/// An interface for collecting the dependencies of a compilation. Users should
/// use \c attachToPreprocessor and \c attachToASTReader to get all of the
/// dependencies.
/// FIXME: Migrate DependencyGraphGen to use this interface.
class DependencyCollector {
public:
virtual ~DependencyCollector();
virtual void attachToPreprocessor(Preprocessor &PP);
virtual void attachToASTReader(ASTReader &R);
ArrayRef<std::string> getDependencies() const { return Dependencies; }
/// Called when a new file is seen. Return true if \p Filename should be added
/// to the list of dependencies.
///
/// The default implementation ignores <built-in> and system files.
virtual bool sawDependency(StringRef Filename, bool FromModule,
bool IsSystem, bool IsModuleFile, bool IsMissing);
/// Called when the end of the main file is reached.
virtual void finishedMainFile(DiagnosticsEngine &Diags) {}
/// Return true if system files should be passed to sawDependency().
virtual bool needSystemDependencies() { return false; }
/// Add a dependency \p Filename if it has not been seen before and
/// sawDependency() returns true.
virtual void maybeAddDependency(StringRef Filename, bool FromModule,
bool IsSystem, bool IsModuleFile,
bool IsMissing);
protected:
/// Return true if the filename was added to the list of dependencies, false
/// otherwise.
bool addDependency(StringRef Filename);
private:
llvm::StringSet<> Seen;
std::vector<std::string> Dependencies;
};
/// Builds a dependency file when attached to a Preprocessor (for includes) and
/// ASTReader (for module imports), and writes it out at the end of processing
/// a source file. Users should attach to the ast reader whenever a module is
/// loaded.
class DependencyFileGenerator : public DependencyCollector {
public:
DependencyFileGenerator(const DependencyOutputOptions &Opts);
void attachToPreprocessor(Preprocessor &PP) override;
void finishedMainFile(DiagnosticsEngine &Diags) override;
bool needSystemDependencies() final { return IncludeSystemHeaders; }
bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem,
bool IsModuleFile, bool IsMissing) final;
protected:
void outputDependencyFile(llvm::raw_ostream &OS);
private:
void outputDependencyFile(DiagnosticsEngine &Diags);
std::string OutputFile;
std::vector<std::string> Targets;
bool IncludeSystemHeaders;
bool PhonyTarget;
bool AddMissingHeaderDeps;
bool SeenMissingHeader;
bool IncludeModuleFiles;
DependencyOutputFormat OutputFormat;
unsigned InputFileIndex;
};
/// Collects the dependencies for imported modules into a directory. Users
/// should attach to the AST reader whenever a module is loaded.
class ModuleDependencyCollector : public DependencyCollector {
std::string DestDir;
bool HasErrors = false;
llvm::StringSet<> Seen;
llvm::vfs::YAMLVFSWriter VFSWriter;
llvm::FileCollector::PathCanonicalizer Canonicalizer;
std::error_code copyToRoot(StringRef Src, StringRef Dst = {});
public:
ModuleDependencyCollector(std::string DestDir)
: DestDir(std::move(DestDir)) {}
~ModuleDependencyCollector() override { writeFileMap(); }
StringRef getDest() { return DestDir; }
virtual bool insertSeen(StringRef Filename) { return Seen.insert(Filename).second; }
virtual void addFile(StringRef Filename, StringRef FileDst = {});
virtual void addFileMapping(StringRef VPath, StringRef RPath) {
VFSWriter.addFileMapping(VPath, RPath);
}
void attachToPreprocessor(Preprocessor &PP) override;
void attachToASTReader(ASTReader &R) override;
virtual void writeFileMap();
virtual bool hasErrors() { return HasErrors; }
};
/// AttachDependencyGraphGen - Create a dependency graph generator, and attach
/// it to the given preprocessor.
void AttachDependencyGraphGen(Preprocessor &PP, StringRef OutputFile,
StringRef SysRoot);
/// AttachHeaderIncludeGen - Create a header include list generator, and attach
/// it to the given preprocessor.
///
/// \param DepOpts - Options controlling the output.
/// \param ShowAllHeaders - If true, show all header information instead of just
/// headers following the predefines buffer. This is useful for making sure
/// includes mentioned on the command line are also reported, but differs from
/// the default behavior used by -H.
/// \param OutputPath - If non-empty, a path to write the header include
/// information to, instead of writing to stderr.
/// \param ShowDepth - Whether to indent to show the nesting of the includes.
/// \param MSStyle - Whether to print in cl.exe /showIncludes style.
void AttachHeaderIncludeGen(Preprocessor &PP,
const DependencyOutputOptions &DepOpts,
bool ShowAllHeaders = false,
StringRef OutputPath = {},
bool ShowDepth = true, bool MSStyle = false);
/// The ChainedIncludesSource class converts headers to chained PCHs in
/// memory, mainly for testing.
IntrusiveRefCntPtr<ExternalSemaSource>
createChainedIncludesSource(CompilerInstance &CI,
IntrusiveRefCntPtr<ExternalSemaSource> &Reader);
/// Optional inputs to createInvocation.
struct CreateInvocationOptions {
/// Receives diagnostics encountered while parsing command-line flags.
/// If not provided, these are printed to stderr.
IntrusiveRefCntPtr<DiagnosticsEngine> Diags = nullptr;
/// Used e.g. to probe for system headers locations.
/// If not provided, the real filesystem is used.
/// FIXME: the driver does perform some non-virtualized IO.
IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS = nullptr;
/// Whether to attempt to produce a non-null (possibly incorrect) invocation
/// if any errors were encountered.
/// By default, always return null on errors.
bool RecoverOnError = false;
/// Allow the driver to probe the filesystem for PCH files.
/// This is used to replace -include with -include-pch in the cc1 args.
/// FIXME: ProbePrecompiled=true is a poor, historical default.
/// It misbehaves if the PCH file is from GCC, has the wrong version, etc.
bool ProbePrecompiled = false;
/// If set, the target is populated with the cc1 args produced by the driver.
/// This may be populated even if createInvocation returns nullptr.
std::vector<std::string> *CC1Args = nullptr;
};
/// Interpret clang arguments in preparation to parse a file.
///
/// This simulates a number of steps Clang takes when its driver is invoked:
/// - choosing actions (e.g compile + link) to run
/// - probing the system for settings like standard library locations
/// - spawning a cc1 subprocess to compile code, with more explicit arguments
/// - in the cc1 process, assembling those arguments into a CompilerInvocation
/// which is used to configure the parser
///
/// This simulation is lossy, e.g. in some situations one driver run would
/// result in multiple parses. (Multi-arch, CUDA, ...).
/// This function tries to select a reasonable invocation that tools should use.
///
/// Args[0] should be the driver name, such as "clang" or "/usr/bin/g++".
/// Absolute path is preferred - this affects searching for system headers.
///
/// May return nullptr if an invocation could not be determined.
/// See CreateInvocationOptions::ShouldRecoverOnErrors to try harder!
std::unique_ptr<CompilerInvocation>
createInvocation(ArrayRef<const char *> Args,
CreateInvocationOptions Opts = {});
} // namespace clang
#endif // LLVM_CLANG_FRONTEND_UTILS_H