llvm/clang/include/clang/Frontend/Utils.h

//===- 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;
class CodeGenOptions;

/// 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,
                            const CodeGenOptions &CodeGenOpts);

/// 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 { … };

/// 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 { … };

/// 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 { … };

/// 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 = { … };

/// 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 { … };

/// 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